U.S. patent application number 14/212176 was filed with the patent office on 2016-12-15 for lens assembly apparatus and method.
The applicant listed for this patent is Manuel Aschwanden, Thomas Kern, Charles King, Dennis Ray Kirchhoefer, David Niederer, Christoph Romer, Thomas Schmidhausler, Daniel Warren, Shu-Heng Yang. Invention is credited to Manuel Aschwanden, Thomas Kern, Charles King, Dennis Ray Kirchhoefer, David Niederer, Christoph Romer, Thomas Schmidhausler, Daniel Warren, Shu-Heng Yang.
Application Number | 20160363737 14/212176 |
Document ID | / |
Family ID | 42729066 |
Filed Date | 2016-12-15 |
United States Patent
Application |
20160363737 |
Kind Code |
A9 |
Aschwanden; Manuel ; et
al. |
December 15, 2016 |
Lens Assembly Apparatus And Method
Abstract
An optical apparatus includes a housing, a deformable lens, and
a lens shaper. The lens shaper defines the shape of the deformable
lens. A first mechanism is positioned within the housing to adjust
an optical property of the deformable lens. A second mechanism is
positioned within the housing to adjust an optical property of the
deformable lens. The second mechanism is at least one of an
electromechanical actuator or motor. The first mechanism and the
second mechanism are different types of mechanisms.
Inventors: |
Aschwanden; Manuel; (Zurich,
CH) ; Niederer; David; (Kuttigen, CH) ;
Schmidhausler; Thomas; (Pfaffikon, CH) ; Romer;
Christoph; (Zurich, CH) ; Kern; Thomas;
(Zurich, CH) ; Yang; Shu-Heng; (Hsinchu, TW)
; King; Charles; (Chicago, IL) ; Kirchhoefer;
Dennis Ray; (Plainfield, IL) ; Warren; Daniel;
(Geneva, IL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Aschwanden; Manuel
Niederer; David
Schmidhausler; Thomas
Romer; Christoph
Kern; Thomas
Yang; Shu-Heng
King; Charles
Kirchhoefer; Dennis Ray
Warren; Daniel |
Zurich
Kuttigen
Pfaffikon
Zurich
Zurich
Hsinchu
Chicago
Plainfield
Geneva |
IL
IL
IL |
CH
CH
CH
CH
CH
TW
US
US
US |
|
|
Prior
Publication: |
|
Document Identifier |
Publication Date |
|
US 20140285911 A1 |
September 25, 2014 |
|
|
Family ID: |
42729066 |
Appl. No.: |
14/212176 |
Filed: |
March 14, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
12720093 |
Mar 9, 2010 |
8699141 |
|
|
14212176 |
|
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|
|
61160041 |
Mar 13, 2009 |
|
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61245438 |
Sep 24, 2009 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G02B 3/14 20130101; H04N
5/2254 20130101; G02B 7/04 20130101; G02B 7/10 20130101; G02B
26/0825 20130101; H04N 5/2328 20130101; G02B 7/182 20130101 |
International
Class: |
G02B 7/10 20060101
G02B007/10 |
Claims
1. An optical apparatus comprising: a housing; a deformable lens; a
lens shaper which defines the shape of the deformable lens; a first
mechanism positioned within the housing to adjust an optical
property of the deformable lens; a second mechanism positioned
within the housing to adjust an optical property of the deformable
lens wherein the second mechanism is at least one of an
electromechanical actuator or motor and further wherein the first
mechanism and the second mechanism are different types of
mechanisms.
2. The optical apparatus of claim 1 wherein the first mechanism
utilizes one or more components selected from the group consisting
of: screws, threads, and mechanical positioning.
3. The optical apparatus of claim 1 further comprising: a locking
mechanism which prevents the first mechanism from further adjusting
an optical property of the deformable lens.
4. The optical apparatus of claim 3 wherein one or more elements of
the locking mechanism involve at least one of a process selected
from a group consisting of: application of adhesive, welding,
clamping and heat staking.
5. The optical apparatus of claim 1 wherein the first mechanism is
removable from the housing.
6. The optical apparatus of claim 1 wherein the deformable lens is
at least partially defined by a container.
7. The optical apparatus of claim 1 wherein deformation of the
deformable lens causes a change in the optical property of the
deformable lens.
8. The optical apparatus of claim 7 wherein the first mechanism
changes a position of the lens shaper with respect to the container
which causes the deformable lens to deform, thereby changing the
optical property of the deformable lens.
9. The optical apparatus of claim 1 further comprising a membrane,
wherein the first mechanism acts to change an initial tension of at
least a portion of the membrane.
10. An optical apparatus comprising: a displacement mechanism; a
container; a lens shaper; wherein the container at least partially
encloses a filler material wherein the filler material at least
partially defines a plurality of deformable lenses, the
displacement mechanism capable of changing an optical property of
at least one of the plurality of deformable lenses.
11. The optical apparatus of claim 10 further comprising a
membrane, wherein the membrane at least partially encloses the
filler material.
12. The optical apparatus of claim 10 further comprising: at least
one light source which interacts with at least one of the plurality
of deformable lenses.
13. The optical apparatus of claim 10 further comprising a
reflector in communication with one or more of the plurality of
deformable lenses.
14. An optical apparatus comprising: a deformable lens; a lens
shaper at least partially defining a shape of the deformable lens;
a support member; and a membrane, wherein the lens shaper and the
support member clamp the membrane such that the membrane is always
in contact with the lens shaper; wherein the deformable lens can
have a convex or a concave shape, and the lens shaper and the
support member are stationary with respect to each other.
15. An optical apparatus comprising: a deformable lens defined at
least by a first membrane and a filler material; a lens shaper,
wherein the deformable lens is in contact with the lens shaper at a
contact region, and not in contact with the lens shaper at a
non-contact region, a first detachment point defined as the
interface between the contact region and the non-contact region;
wherein the first detachment point defines a diameter of the
deformable lens; wherein a shape of the lens shaper allows for a
location of the first detachment point to vary with deformation of
the deformable lens, such that the diameter of the deformable lens
varies with the location of the first detachment point.
16. The optical apparatus of claim 15 wherein an axial position of
the detachment point varies with the deformation of the deformable
lens.
17. The optical apparatus of claim 15 further comprising: a first
support member; a second membrane which is a subset of the first
membrane that is in contact with the lens shaper at the contact
region; a third membrane which is connected with an end of the
second membrane and the first support member; a second detachment
point which is located at a connection point between the second
membrane and the third membrane; a first theoretical line which is
tangent to the lens shaper at the first detachment point and a
second theoretical line which is tangent to the lens shaper at the
second detachment point; a connection angle defined as an angle
between the first theoretical line and the second theoretical line
and is a supplementary angle to an angle that contains a majority
of the lens shaper; a connection angle positive sense defined as
being in a direction from the second theoretical line through the
first theoretical line and towards the lens shaper wherein the
connection angle does not span across the lens shaper; wherein the
absolute value of the connection angle is between 0 and 180
degrees.
18. The optical apparatus of claim 15 wherein only frictional
forces are used to hold the first membrane to the lens shaper.
19. The optical apparatus of claim 15 further comprising: a second
lens shaper; and a third lens shaper, wherein deformation of the
deformable lens causes the lens shaper to shift from the second
lens shaper to the third lens shaper and changes the diameter of
the deformable lens.
20. The optical apparatus of claim 15 further comprising: a second
lens shaper; and a third lens shaper, wherein deformation of the
deformable lens causes the detachment point to shift from the
second lens shaper to the third lens shaper and changes an axial
position of the deformable lens.
21. An optical apparatus comprising: a deformable lens capable of
assuming a plurality of shapes; a lens shaper at least partially
defining a shape of the deformable lens; an actuation device
capable of changing at least one optical property of the deformable
lens; wherein an inner surface of the lens shaper extends from a
first face having a first perimeter having a first shape, to a
second face having a second perimeter having a second shape,
wherein the first shape and the second shape are different; wherein
the shape of the deformable lens can be defined by either the first
face of the lens shaper or the second face.
22. The optical apparatus of claim 21 wherein the first face of the
lens shaper is substantially circular and the second face of the
lens shaper is substantially non-circular.
23. The optical apparatus of claim 21 wherein the first face of the
lens shaper is substantially non-circular and the second face of
the lens shaper is substantially non-circular.
Description
CROSS REFERENCES TO RELATED APPLICATIONS
[0001] This patent is a division of U.S. application Ser. No.
12/720,093, filed Mar. 9, 2010, which claims benefit under 35
U.S.C. .sctn.119 (e) to U.S. Provisional Application No. 61/160,041
entitled "Lens Assembly System and Method" filed Mar. 13, 2009
having attorney docket number PO9007 and U.S. Provisional
Application No. 61/245,438 entitled "Lens Assembly Apparatus and
Method of Operation" filed Sep. 24, 2009 having attorney docket
number PO9010 the contents of all of which are incorporated herein
by reference in their entireties.
TECHNICAL FIELD
[0002] This patent relates to optical apparatuses which incorporate
lenses and methods of operating lenses.
BACKGROUND OF THE INVENTION
[0003] Various optical lens systems have been used over the years
for different purposes. For instance, some lens systems provide for
magnification of an image while other lens systems provide for
zooming in on an image. Lens systems can also be used for various
applications and/or in different environments. For example, a lens
system may be part of a digital camera and the user may wish to
zoom in on objects that are far away in order to obtain images of
these objects or to focus on objects that are close. In other
examples, the lens system may be part of a camera in a cellular
phone or other small electronic device where the user desires to
obtain nearby images.
[0004] While various types of lens systems have been employed in
various applications, these previous systems suffered from several
disadvantages. To take one example, due to the desired
miniaturization of systems, system components need to be as small
as possible. Unfortunately, previous systems had components that
were bulky and miniaturization became difficult to accomplish.
Previous systems also often used a wide variety of moving parts
that frequently moved along an axis of the lens system.
Unfortunately, these moving parts had a tendency to break requiring
the replacement of system components and leading to the
unreliability of these previous approaches. These systems also
utilized a large number of parts and this also added to the
unreliability (and cost) of these approaches. For all these
reasons, previous systems were costly to produce and user
satisfaction with these systems was often negatively impacted by
the above-mentioned disadvantages.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] For a more complete understanding of the disclosure,
reference should be made to the following detailed description and
accompanying drawings wherein:
[0006] FIGS. 1A and 1B illustrate a cross-sectional view of a
magnetic coil lens assembly according to various embodiments of the
present invention;
[0007] FIGS. 2A and 2B illustrates a cross-sectional view of a
magnetic coil lens assembly according to various embodiments of the
present invention in which a coil is positioned on both sides of a
membrane;
[0008] FIG. 3 illustrates a cross-sectional view of a magnetic coil
lens assembly according to various embodiments of the present
invention in which a plurality of coils are positioned to move a
plurality of membranes;
[0009] FIG. 4 includes cross-sectional drawings that illustrate a
production process for assembling a deformable lens and removing
gas bubbles from a lens assembly according to various embodiments
of the present invention;
[0010] FIG. 5 comprises a flowchart that together with the
cross-sectional drawings of FIG. 4 illustrate a production process
for assembling a deformable lens and removing gas bubbles from a
lens assembly according to various embodiments of the present
invention;
[0011] FIG. 6 illustrates a cross-sectional view of a magnetic coil
lens assembly having a single axially polarized motor according to
various embodiments of the present invention;
[0012] FIG. 7 illustrates a perspective view of a lens defining
structure of the example of FIG. 6 according to various embodiments
of the present invention;
[0013] FIG. 8 illustrates a cross-sectional view of a flux guiding
structure in a magnetic coil lens assembly according to various
embodiments of the present invention where a single motor structure
drives two coils;
[0014] FIG. 9 illustrates a perspective cross-sectional view of a
motor structure to activate a dual variable lens structure
according to various embodiments of the present invention;
[0015] FIG. 10 illustrates a perspective cross-sectional view of a
magnetic structure which is used to define a lens and/or reservoir
shaping point according to various embodiments of the present
invention;
[0016] FIG. 11 illustrates a perspective cross-sectional view of a
magnetic coil lens assembly having magnets which are distributed
into corners of a flux guiding structure according to various
embodiments of the present invention;
[0017] FIG. 12 illustrates an isolated perspective view of a coil
and bobbin arrangement of the example of FIG. 11 according to
various embodiments of the present invention;
[0018] FIGS. 13A and 13B illustrate an isolated perspective view of
the coil and bobbin arrangement of FIG. 12 with magnets positioned
in corners of the arrangement according to various embodiments of
the present invention;
[0019] FIG. 14 illustrates a perspective cross-sectional view of a
magnetic coil lens assembly having a lens shaper sleeve according
to various embodiments of the present invention;
[0020] FIG. 15 illustrates a coil connection in a magnetic lens
assembly according to various embodiments of the present
invention;
[0021] FIG. 16 illustrates a perspective cross-sectional view of
the magnetic lens assembly of the example of FIG. 15 according to
various embodiments of the present invention;
[0022] FIGS. 17A and 17B illustrate whole and cross-sectional
perspective views of a magnetic lens assembly having two tunable
lenses stacked in a housing according to various embodiments of the
present invention;
[0023] FIG. 18 illustrates an isolated view of a bobbin-membrane
interface of a magnetic lens assembly according to various
embodiments of the present invention;
[0024] FIG. 19 illustrates another isolated view of the
bobbin-membrane interface where the membrane is clamped and
mechanically held in the bobbin of FIG. 18 according to various
embodiments of the present invention;
[0025] FIG. 20a illustrates a lens assembly in which a positioning
of a reservoir and lens is optimized for space reduction according
to various embodiments of the present invention;
[0026] FIG. 20b illustrates another view of the lens assembly of
FIG. 20a in which a positioning of a reservoir and lens is
optimized for space reduction according to various embodiments of
the present invention;
[0027] FIG. 21 illustrates another lens assembly in which a
positioning of a reservoir and the bobbin shape and lens is
optimized for space reduction according to various embodiments of
the present invention;
[0028] FIGS. 22A and 22B illustrate a lens assembly utilizing
piezo-actuation according to various embodiments of the present
invention;
[0029] FIGS. 23A, 23B and 23C illustrates an interior view of the
lens assembly of FIG. 22 according to various embodiments of the
present invention;
[0030] FIGS. 24A and 24B illustrates a perspective view of a lens
assembly having a voice coil actuator with a double wound coil
according to various embodiments of the present invention;
[0031] FIG. 25 illustrates a perspective isolated view of upper and
lower coils of the assembly of FIG. 24 showing the lower coil wound
opposite of the upper coil according to various embodiments of the
present invention;
[0032] FIG. 26 illustrates an isolated cross-sectional view of the
assembly of FIG. 24 according to various embodiments of the present
invention;
[0033] FIGS. 27A and 27B illustrates a perspective view of the
assembly of FIG. 26 and further illustrates current flow and
magnetic field flow on a top part of the assembly in one direction
and on a bottom part in the opposite direction according to various
embodiments of the present invention;
[0034] FIG. 28 illustrates a field guiding ring that optimizes the
magnetic flux generated by the assembly of FIG. 26 according to
various embodiments of the present invention;
[0035] FIG. 29 illustrates magnetic flux generated by the assembly
of FIG. 26 in which the magnets are polarized at an angle according
to various embodiments of the present invention;
[0036] FIG. 30 illustrates a perspective cross-sectional view of a
lens assembly in which a bobbin is a lens defining structure
according to various embodiments of the present invention;
[0037] FIG. 31 illustrates an isolated view of a beveled contact
point for a membrane and inner diameter of a ring structure of a
lens assembly according to various embodiments of the present
invention;
[0038] FIG. 32 illustrates a perspective cross-sectional view of a
lens assembly according to various embodiments of the present
invention;
[0039] FIG. 33 illustrates a perspective cross-sectional view of
another lens assembly according to various embodiments of the
present invention;
[0040] FIG. 34 illustrates a perspective cross-sectional view of
still another lens assembly according to various embodiments of the
present invention;
[0041] FIG. 35 illustrates a perspective cross-sectional view of
another lens assembly according to various embodiments of the
present invention;
[0042] FIG. 36 illustrates a perspective cross-sectional view of
yet another lens assembly according to various embodiments of the
present invention;
[0043] FIGS. 37A-T illustrate various views of another example of a
lens assembly according to various embodiments of the present
invention;
[0044] FIGS. 38A-F illustrate various views of a lens assembly
showing one example of the optimization of bobbin design according
to various embodiments of the present invention;
[0045] FIGS. 39A-E illustrate various views of another example of a
lens aperture, reservoir, and magnetic subassemblies according to
various embodiments of the present invention;
[0046] FIGS. 40A-C illustrate various views of another example of a
lens assembly according to various embodiments of the present
invention;
[0047] FIGS. 41A-B illustrate various views of another example of a
lens assembly according to various embodiments of the present
invention;
[0048] FIGS. 42A-D illustrate various lens configurations according
to various embodiments of the present invention;
[0049] FIG. 43 illustrates alignment of the coil and magnet
according to various embodiments of the present invention;
[0050] FIG. 44 comprises a flowchart of one example the operation
of a lens assembly according to various embodiments of the present
invention;
[0051] FIGS. 45A-45C comprise various perspective cross-sectional
views of a lens assembly according to various embodiments of the
present invention;
[0052] FIGS. 46A and 46B comprise perspective exploded and
cross-sectional views of another example of a lens assembly
according to various embodiments of the present invention;
[0053] FIGS. 47A-47D comprise perspective cross-sectional and
exploded views of a lens assembly according to various embodiments
of the present invention in which a plurality of one or more motors
are positioned to deform a plurality of membranes;
[0054] FIGS. 48A-48C comprise perspective cross-sectional and
exploded views of a lens assembly having tiltable lens according to
various embodiments of the present invention;
[0055] FIG. 49 comprises a perspective cross-sectional view of a
lens assembly according to various embodiments of the present
invention;
[0056] FIGS. 50A-50D comprise perspective cross-sectional and
exploded views of a lens assembly according to various embodiments
of the present invention;
[0057] FIGS. 51A-51B comprise perspective cross-sectional and
exploded views of a lens assembly according to various embodiments
of the present invention;
[0058] FIGS. 52A-52C comprise perspective and cross-sectional views
of a lens assembly according to various embodiments of the present
invention in which various types of linkage structures are used to
effectuate lens movement;
[0059] FIGS. 53A-53D is one example of a voltage waveform applied
to a piezoelectric motor according to various embodiments of the
present invention;
[0060] FIGS. 54A-D comprise various diagrams of a mechanical
linkage structure and operation and movement of the linkage
structure according to various embodiments of the present
invention;
[0061] FIGS. 55A-B comprise various perspective diagrams of
mechanical linkages according to various embodiments of the present
invention
[0062] FIGS. 56A and 56B comprise diagrams of a lens assembly
according to various embodiments of the present invention;
[0063] FIGS. 57A and 57B comprise perspective views of a lens
assembly according to various embodiments of the present
invention;
[0064] FIGS. 58A, 58B, 58C, and 58D comprise views of actuators in
lens assemblies according to various embodiments of the present
invention;
[0065] FIGS. 59A and 59B comprise views of a lens assembly
according to various embodiments of the present invention;
[0066] FIG. 60 comprises a view of a lens assembly according to
various embodiments of the present invention;
[0067] FIG. 61 comprises a perspective view of a lens array
assembly according to various embodiments of the present
invention;
[0068] FIG. 62A and FIG. 62B comprise views of a lens assembly
according to various embodiments of the present invention;
[0069] FIG. 63A and FIG. 63B comprise views of a lens assembly
according to various embodiments of the present invention;
[0070] FIG. 64A and FIG. 64B comprise views of a lens assembly
according to various embodiments of the present invention;
[0071] FIG. 65A and FIG. 65B comprise views of a lens shaper
according to various embodiments of the present invention.
[0072] Skilled artisans will appreciate that elements in the
figures are illustrated for simplicity and clarity. It will further
be appreciated that certain actions and/or steps may be described
or depicted in a particular order of occurrence while those skilled
in the art will understand that such specificity with respect to
sequence is not actually required. It will also be understood that
the terms and expressions used herein have the ordinary meaning as
is accorded to such terms and expressions with respect to their
corresponding respective areas of inquiry and study except where
specific meanings have otherwise been set forth herein.
DETAILED DESCRIPTION
[0073] Many of the present approaches provide a magnetic lens
assembly that includes a magnetic-coil actuator (e.g., a voice coil
motor) which deforms one or more membranes (e.g., a polymeric
membrane) in the lens assembly. Other devices such as piezo
electric devices could also be used. In many of these examples, the
membrane may define at least partially one or more reservoirs that
are filled with a filler material (e.g., liquid, gel, or polymer).
The membrane, filler material, and a container opposite the
membrane, may provide a lens. It should be noted that the teen
"lens" should be interpreted, in most if not all of the following
embodiments--as applicable--as "a three dimensional space filled
with a filler material and communicating with a reservoir." The
resulting deformation of the membrane occurs via pressure provided
from movement of the filler material (e.g., optical fluid) within
the reservoir. Deformation of the lens alters the optical
characteristics of the lens as desired or required. Consequently,
miniaturization is achieved, overall part count is reduced, the
number of moving parts is decreased, costs are reduced, system
weight is decreased, and system reliability is increased.
[0074] In many of these embodiments, a lens assembly includes a
moving coil, a flux guiding structure, one or more magnets, and a
lens. The lens includes a membrane that at least partially defines
a reservoir (e.g., a fluid reservoir). The coil is excited by
current and a magnetic flux forms and is directed by the flux
guiding structure. The flux creates an electromotive force that
moves the coil. The force may be related to the strength of the
magnetic field, multiplied by the length of the wire and the
current flowing through the wire. The movement of the coil acts to
push or pull the membrane and thereby move the filler material
(e.g., fluid) within the reservoir creating a pressure and thereby
deforming the shape of the membrane and overall lens. Consequently,
the optical properties of the lens are altered. Put another way,
the optically active area of the membrane is altered. Such lenses
are sometime referred to herein as focus tunable lenses or fluid
tunable lenses.
[0075] In other examples, the position of the coil is fixed.
Excitation of the coil moves magnetized parts, which in turn move
the membrane. Hence, the optical properties of the lens are
adjusted.
[0076] A housing structure (e.g., plastic) may be used to support
all or some of the assembly elements. In some examples, portions of
the housing structure are pushed (or pulled) by the coil to push
(or pull) the membrane. In many examples, a bobbin pushes on the
membrane.
[0077] As mentioned, if a motor is employed as the actuator, the
motor structure may include several members including one or more
permanent magnets and a flux guiding structure having one or more
parts or portions. The flux guiding structure guides and directs
the magnetic field to produce an electromotive force of sufficient
magnitude and direction to move the coil as desired.
[0078] Additionally, the motor structure may include various parts
that provide fixturing and alignment functions for the assembly
(e.g., support and definition of the shape or other properties of
the membrane or other portions of the lens). In this regard, the
flux guiding structure may also provide for the housing of the
lens, define the lens shape, support the lens structure, define the
boundary conditions of the reservoir, support the components that
define the reservoir, provide structure to the assembly, and/or
define one or more reservoirs. Moreover, these tasks may be
performed at the same time as the flux guiding structure provides
magnetic field direction and guidance.
[0079] The coil component of the magnetic lens is directly attached
to or indirectly interacts with (via another element or elements
such as a bobbin) the membrane, which as mentioned, is deformable.
Also as mentioned, the membrane defines one or more reservoirs.
These reservoirs may be filled with a polymer, gel, fluid, or ionic
liquid to name a few examples of filler materials. Other examples
of filler materials are possible.
[0080] In some of these examples, the coil interacts with the
membrane on a side of the membrane that does not contain the filler
material (e.g., a fluid). Consequently, the reservoir can be filled
in a more convenient manner without entrapping air bubbles in the
reservoir since edges from the coil may not exist inside the
reservoir. Additionally, electrical connections between the coil
and devices external to the assembly are easier to accomplish
because the coil is in an air-only space.
[0081] Coil placement may vary. For example, the coil may be placed
within the reservoir (e.g., within a liquid that fills the
reservoir), partially within the reservoir (e.g., on both sides of
the reservoir separated by the membrane), or completely outside the
reservoir (on one or both sides of the reservoir). When fitted
within the reservoir, the coil may also float in the reservoir. As
mentioned, the coil may also be fixed in position in some of these
examples.
[0082] The coil can be electrically connected to the other portions
of the assembly by various approaches. For example, in one
embodiment, the coil wires can be connected with the flux guiding
structure, which is electrically insulated by or from the permanent
magnet. In another embodiment, the wires are guided outside of the
assembly through holes in the housing, magnet and/or the
metal-based structure. In still another embodiment, the wires are
connected to a metal structure (e.g., a metal spring), or connected
or integrated to portions of the assembly (e.g., the bobbin). In
yet another embodiment, the wires are guided outside through
holes/slits in the assembly and fixed onto a metal structure
integrated into the interior of the assembly. In other examples,
the wires may be coupled to an electrically conductive
membrane.
[0083] In some of these embodiments, a push approach is used where
the coil (or bobbin) pushes on the membrane to achieve deformation.
In other examples, a push-pull approach is used where the membrane
is both pushed and pulled. The membrane and coil (or bobbin) are
attached by an adhesive (e.g., glue) or any other type of fastener
arrangement (e.g., screws, snap connectors, ultrasonic welding, hot
melting, or the like). Pull only approaches may also be used. The
determination of the type of approach used may depend upon, among
other factors, the overall height desired for the assembly and a
starting focus or zoom position of lenses used in the assembly.
[0084] The approaches described herein can be used to form various
types of lens assemblies having any number of lenses used in any
combination or order. For example, any number of the tunable lenses
described herein can be used in conjunction with other optical
elements or lenses to form any type of optical assembly.
[0085] The present approaches additionally provide a lens assembly
that includes an electrical-to-mechanical actuation device (e.g., a
piezoelectric motor or some other type of actuation device) that
deforms one or more membranes in the lens assembly. In some of
these embodiments, a lens (e.g., a fluid lens) is formed between or
bounded by a membrane (e.g., a polymeric membrane) and a container
(e.g., a glass plate, optical element, lens, or some other
structure). The membrane and/or container may also define at least
partially one or more reservoirs that are filled with a filler
material. The reservoirs communicate with the lens (e.g., a fluid
or gel lens) through holes, channels, slits, or the like and the
piezoelectric motor is coupled directly or indirectly to the
container. Together, the container and the membrane function to
hold the filler material in the reservoir(s) section(s) and lens
section(s). Actuation of the electrical-to-mechanical actuation
device causes movement of the container (e.g., in the area of the
reservoir) which, in turn, moves the filler material between the
reservoir and the lens area to create a pressure and thereby deform
the membrane. The resultant deformation of the membrane and
movement of the filler material alters the optical characteristics
of the lens as desired or required. Consequently, miniaturization
is achieved, overall part count is reduced, the number of moving
parts is decreased, costs are reduced, system weight is decreased,
and system reliability is increased.
[0086] It will be understood that various types of
electrical-to-mechanical actuation devices may be used in the
approaches described herein to move components of the lens
assembly. For example and as mentioned, piezoelectric motors may be
used. However, it will be appreciated that these approaches are not
limited to the use of piezoelectric motors but may, for example,
include any motor or motor-like device such as miniature stepper
motors or screw drive motors to name two examples. In other words,
although many of the examples described herein utilize a
piezoelectric motor, any other type of motor (or other
electrical-to-mechanical actuation device) may also be used.
[0087] In others of these embodiments, a lens assembly includes a
piezoelectric motor (or some other type of electrical-to-mechanical
actuation device), a linkage structure, and a container and
membrane assembly. The container and membrane assembly includes a
membrane that at least partially defines one or more reservoirs
(e.g., a fluid reservoir) and a lens (e.g., a fluid or gel lens)
such that a liquid filler material (e.g., a fluid or gel) is able
to flow or otherwise move between the reservoir(s) and the lens.
The piezoelectric motor is actuated by an electrical signal. The
actuation of the piezoelectric motor (and deformation of a
piezoelectric material located therein) directly or indirectly
pushes or pulls the linkage structure which, in turn, directly or
indirectly acts on the reservoir of the lens assembly to move the
filler material (e.g., optical fluid) between the reservoir and the
lens. Movement of the filler material creates a pressure against
the membrane and thereby deforms the shape of the membrane to alter
the optical properties of the lens. A lens shaper may be attached
to a portion of the membrane to form and/or define the outer
perimeter of the lens. A housing structure may be used to support
all or some of the assembly elements. In some examples, portions of
the housing structure are pushed (or pulled) by the piezoelectric
motor (or other type of electrical-to-mechanical actuation device)
to push (or pull) the membrane via actuation of the linkage
structure.
[0088] As mentioned, if a piezoelectric motor is employed as the
electrical-to-mechanical actuation device, the piezoelectric motor
structure may include several members including one or more
piezoelectric elements that move a linkage structure having one or
more parts or portions. More specifically, the linkage structure
may include one or more elements that act to receive a mechanical
force from the motor and guide and direct this force to move (e.g.,
push or pull) the membrane. The linkage structure may include one
or more pins, paddles, rings, rods, bobbins, hinges, or pivots to
name a few examples. In other examples, the separate linkage
structure may be omitted and portions of the motor may act directly
on the membrane.
[0089] Additionally, the linkage structure may include various
parts that provide fixturing and alignment functions for the
assembly (e.g., support and definition of the shape or other
properties of the membrane or other portions of the lens). In this
regard, the linkage structure may also provide for the housing of
the lens, define the lens shape, support the lens structure, define
the boundary conditions of the reservoir, support the components
that define the reservoir, provide structure to the assembly,
and/or define one or more reservoirs. These functions may also be
at least partially provided by other elements not in the linkage
structure.
[0090] As mentioned, the membrane may define the side of one or
more reservoirs and a lens shape. The reservoirs and lens may be
filled with a filler material such as a polymer, gel, or fluid to
name a few examples of filler materials. Other examples of filler
materials are also possible. The inner perimeter of the lens shaper
defines the outer perimeter of the inner section of the membrane,
and restrains the membrane from moving at the edge of the lens
shaper.
[0091] The placement of the electrical-to-mechanical actuation
device may also vary in the present approaches. For example when a
piezoelectric motor is used, the piezoelectric motor may be placed
within the reservoir (e.g., within a liquid that fills the
reservoir), partially within the reservoir (e.g., on both sides of
the reservoir separated by the membrane or container), or
completely outside the reservoir (on one or both sides of the
reservoir).
[0092] The electrical-to-mechanical actuation device (e.g., a
piezoelectric motor) can be electrically connected to the other
portions of the assembly by various approaches. For example, in one
embodiment the connection wires are guided outside of the assembly
through holes in the housing. In still another embodiment, the
wires are connected to a metal structure (e.g., a metal spring), or
connected or integrated to portions of the assembly. In yet another
embodiment, the wires are guided outside through holes/slits in the
assembly and fixed onto a metal structure integrated into the
interior of the assembly.
[0093] In some of these embodiments, a push-only approach is used
by the motor to directly or indirectly push the container (e.g.,
via the linkage structure) and achieve deformation of the membrane,
thereby altering an optical property of the lens. In other
examples, a push-pull approach is used where the container (or some
other element) is both pushed and pulled. Attachment of the motor,
the container, and the linkage structure may be accomplished via
various approaches such as by an adhesive (e.g., glue) or any other
type of fastener arrangement (e.g., screws, nails, or the like).
Pull-only approaches may also be used. The determination of the
type of approach used to move the container (and achieve lens
deformation) may depend upon, among other factors, the overall
height desired for the assembly and a starting focus or zoom
position of lenses used in the assembly.
[0094] In many of these embodiments, an optical apparatus includes
a first membrane, a second membrane, and at least one
electromagnetically displaceable component. The first membrane
includes an optically active area. The first membrane and the
second membrane are coupled by a filler material disposed in a
reservoir. The at least one electromagnetically displaceable
component is coupled to the filler material via the second
membrane, such that a displacement of the at least one
electromagnetically displaceable component is operative to cause a
deformation of the optically active area of the first membrane by
movement of the filler material.
[0095] The filler material may be a liquid, an ionic liquid, a gel,
a gas, and a polymer. Other examples of filler materials are
possible. In some aspects, the filler material and the membrane are
the same material.
[0096] In one example, the electromagnetically displaceable
component includes a coil. In another example, the
electromagnetically displaceable component includes at least one
magnet. In some examples, the electromagnetically displaceable
component is constructed from a magnetically soft material.
[0097] In some approaches when a coil is used, applying the current
to the electrical coil is operative with a magnetic field to create
an electromotive force and to move the electrical coil in a
generally axial direction with respect to the optical axis of the
lens. In some aspects, the coil is stationary with respect to the
container and the at least one magnet is movable with respect to
the coil.
[0098] In yet other embodiments, the electromagnetically
displaceable component is mechanically coupled to the second
membrane, such that a deformation of the second membrane results in
a deformation of the first membrane by movement of the filler
material. In some other examples, the electromagnetically
displaceable component is attached to the second membrane section
by an attachment mechanism such as by mechanical adhesion, chemical
adhesion, dispersive adhesion, electrostatic adhesion and diffusive
adhesion.
[0099] In other aspects, the electromagnetically displaceable
component delimits at least one of the first membrane and the
second membrane. In still other examples, the first membrane and
the second membrane are delimited from each other by a lens shaper.
In some approaches, the lens shaper comprises a circular opening
which defines the shape of the optically active area of the first
membrane.
[0100] In some of these examples, the at least one
electromagnetically displaceable component is positioned on either
side of the second membrane. In other approaches, the second
membrane laterally surrounds the first membrane. In yet other
examples, the electromagnetically displaceable component laterally
surrounds the first membrane.
[0101] In some of these approaches, at least one of the first
membrane or the second membrane are arranged in a pre-stretched
manner. In other aspects, the membrane is at least partially
constructed from at least one material such as gels, elastomers,
thermoplast, and duroplast. Other examples of materials can be used
to construct the membrane.
[0102] In other aspects, the coil comprises a bobbin, which is
attached to the second membrane and an electrically conductive
wire, which is arranged on the bobbin. In some approaches, the
bobbin is constructed from a rigid material.
[0103] In still other aspects, the coil operates to interact with a
magnetized structure. In some of these examples, the magnetized
structure comprises at least one magnet. The magnetized structure
comprises a flux guiding structure and the flux guiding structure
may be constructed from a magnetically soft material. In some
aspects, a periphery of the magnetized structure is substantially
rectangular in shape.
[0104] The optical apparatus so constructed can be used in a wide
variety of systems such as optical focusing systems, zoom systems,
and illumination systems. Other examples of systems are
possible.
[0105] In others of these embodiments, an optical apparatus
includes at least one electromagnetically displaceable component
and a continuous membrane. The membrane has a first membrane
section and a second membrane section and the second membrane
section extends from the first membrane section. The first membrane
section and the second membrane section are coupled via a filler
material. A displacement of the at least one electromagnetically
displaceable component causes movement of the second membrane
section, thereby causing movement of the filler material that
deforms at least a part of the first membrane section.
[0106] In some aspects, the filler material is a deformable
material. In other aspects, the electromagnetically displaceable
component includes a coil. In still other aspects, the
electromagnetically displaceable component includes a magnet. In
yet other aspects, the electromagnetically displaceable component
is constructed from a magnetically soft material.
[0107] In some of these examples, the electromagnetically
displaceable component is attached to the second membrane section
by an attachment mechanism such as by mechanical adhesion, chemical
adhesion, dispersive adhesion, electrostatic adhesion and diffusive
adhesion.
[0108] In other aspects, the electromagnetically displaceable
component delimits at least one of the first membrane section and
the second membrane section. In some examples, the first membrane
section and the second membrane section are delimited from each
other by a lens shaper. In some approaches, the lens shaper
comprises a circular opening which defines the shape of the
optically active area of the first membrane section. In other
examples, the electromagnetically displaceable component surrounds
the first membrane section.
[0109] In other aspects, at least one of the first membrane section
and the second membrane section may be arranged in a pre-stretched
manner. The membrane may be at least partially constructed from at
least one material selected from gels, elastomers, thermoplast, and
duroplast. Other examples of materials are possible.
[0110] In other examples, the coil is coupled to a bobbin which is
attached to the second membrane. When a bobbin is used, the bobbin
may be constructed from a rigid material.
[0111] In some aspects, the coil operates to interact with a
magnetized structure. In some approaches, the magnetized structure
comprises at least one magnet. In other aspects, the magnetized
structure comprises a flux guiding structure. The flux guiding
structure may be constructed from a magnetically soft material.
[0112] In some examples, the electromagnetically displaceable
component is part of a motor system. In some approaches, a
periphery of the motor system is substantially rectangular in
shape.
[0113] The apparatus may be used in a wide variety of different
systems. For example it may be at least part of an optical focusing
system, zoom system, and illumination system. Other examples of
systems are possible.
[0114] In yet others of these embodiments, an optical apparatus
includes at least one actuator element, a mechanical linkage
element, a lens, a reservoir in communication with the lens, a
membrane, and a container. The membrane and the container at least
partially enclose a filler material and the membrane is coupled to
the mechanical linkage element. Electrical excitation of the at
least one actuator element is operative to causes a plurality of
movements of the at least one actuator element. Each of the
plurality of movements occurs over a first distance, and the
plurality of movements of the at least one actuator element are
operative to move the mechanical linkage element a second distance.
The second distance is substantially greater than the first
distance, and the movement of the mechanical linkage element causes
a displacement of the membrane and the filler material. The
displacement of the filler material alters at least one optical
property of the lens.
[0115] In some aspects, the at least one actuator element includes
a piezo actuator element. The piezo actuator element may be part of
a piezo motor.
[0116] In other aspects, the actuator element is at least part of
one of a piezo motor, stepper motor, voicecoil motor, screw drive
motor, microelectromechanical system motor, or magnetostrictive
motor. In yet other aspects, the filler material and the membrane
are constructed from the same material. In some examples, the
membrane is arranged in a pre-stretched manner. In some approaches,
the membrane is at least partially constructed from at least one
material such as gels, elastomers, thermoplast, and duroplast.
[0117] The apparatus may be at least part of one of an optical
focusing system, zoom system, and illumination system. Other
examples of systems are possible.
[0118] In others of these embodiments, a motor includes a first
magnet; a first coil placed proximate to the first magnet; a second
magnet; a second coil placed proximate to the second magnet; a
first flux which is generated by the first magnet; a second flux
generated by the second magnet; and a third flux which is generated
by both the first and second magnet. A current excitation of the
first coil is operative with the first and third flux to create a
sufficient force to displace the first coil with respect to the
first magnet and excitation of the second coil is operative with
the second and third flux to create a sufficient force to displace
the second coil with respect to the second magnet. At least some of
the first flux, the second flux, or the third flux passes through a
deformable optical element.
[0119] In some aspects, a flux guiding structure is arranged such
that the flux guiding structure increases the flux density at the
first coil and the second coil and the flux guiding structure
optimizes the force. In other examples, the third flux is a
significant portion of the total flux and increases the flux
density at the coils. In some approaches, the first coil is
mechanically coupled to an optical element. The motor may also
include at least one additional magnet configured to increase the
flux density at the coils.
[0120] In others of these embodiments, an optical apparatus
includes a deformable lens, a first reservoir, an optical sensor,
and a motor. The first reservoir communicates with the deformable
lens. The optical sensor receives light which passes through the
deformable lens. The motor includes a first magnet; a first coil
placed proximate to the first magnet; and a first flux which is
generated by the first magnet wherein the first flux flows through
a first coil and interacts with current in the first coil to create
a force. A portion of the motor is positioned between the first
reservoir and the optical sensor. In other examples, the optical
apparatus further includes a second reservoir and a portion of the
motor is positioned between the first reservoir and the second
reservoir.
[0121] In still others of these embodiments, an optical apparatus
includes a semi-permeable membrane, a container, a lens, and a
filler material. The lens is defined by the semi-permeable membrane
and the container. The filler material is disposed within the lens
and contained therein by the membrane and the container. The
semi-permeable membrane is at least partially constructed from a
material that is permeable to gases but substantially impermeable
to the filler material and the gases residing within the lens
diffuse through the membrane when the lens is closed by the
membrane and the container. The optical properties of the optical
apparatus are changed by deforming the filler material.
[0122] The optical apparatus may further include a mechanically
displaceable component that is mechanically coupled to the semi
permeable membrane. In some examples, the semi-permeable membrane
has physical properties wherein at least approximately 90% of the
gas trapped between the semi-permeable membrane and the container
diffuses through the semi-permeable membrane within less than
approximately 24 hours when a pressure difference of approximately
one atmosphere exists across the semi-permeable membrane. Other
examples are possible.
[0123] In others of these embodiments, an optical apparatus
includes a deformable lens, a motor, and a mechanical linkage. The
deformable lens has an optical axis and the mechanical linkage is
actuated by the motor and coupled to the deformable lens through a
filler material, such that an interface exists between the
mechanical linkage structure and the filler material. The interface
substantially surrounds the optical axis.
[0124] In some examples, the motor moves a first distance and the
first distance is less than a peak displacement of the deformable
lens. In other examples, the motor moves in an axial direction. In
some examples, the mechanical linkage disposed at the interface
between the filler material and the mechanical linkage is
substantially non-deformable.
[0125] In other aspects, the mechanical linkage structure provides
a non-deformable surface at the interface. The filler material
provides a deformable area adjacent to the interface. The
non-deformable surface is in a range from approximately 25 percent
to approximately 900 percent of the deformable area. In some
examples, the mechanical linkage also includes a bobbin which is
attached to an electrically conductive coil.
[0126] In others of these embodiments, an optical apparatus
includes an actuator device, a lens, a reservoir, a membrane, and a
container. The actuator device includes at least one piezo motor
and the at least one piezo motor has a first portion and a second
portion and a piezo actuator and the second portion is movable with
respect to the first portion and coupled to a linkage structure.
The reservoir is in communication with the lens. The membrane and a
container at least partially enclose the filler material within the
lens and reservoir and the membrane is mechanically coupled with
the linkage structure. Excitation of the at least one piezo motor
is operative to move the second portion of the at least one piezo
motor to move the linkage structure and cause a displacement of the
membrane and the filler material. The displacement of the filler
material alters at least one optical property of the lens.
[0127] In still others of these embodiments, an optical apparatus
includes at least one piezo motor, a lens, a reservoir, a membrane,
and a container. The reservoir is in communication with the lens.
The membrane and a container at least partially enclose a filler
material within the lens and reservoir. A linkage member is coupled
to the at least one piezo motor and the membrane and the linkage
member is rotatable about a hinge. Excitation of the at least one
piezo motor is operative to rotate the linkage member about the
hinge and create a substantially axial directed force that is
operative to cause a displacement of the membrane and the filler
material. The displacement of the filler material altering at least
one optical property of the lens.
[0128] In still others of these embodiments, an optical apparatus
includes a housing, a deformable lens, a lens shaper, a first
mechanism, and a second mechanism. The lens shaper defines the
shape of the deformable lens. The first mechanism is positioned
within the housing to adjust an optical property of the deformable
lens. The second mechanism is positioned within the housing to
adjust an optical property of the deformable lens. The second
mechanism is at least one of an electromechanical actuator or motor
and the first mechanism and the second mechanism are different
types of mechanisms.
[0129] In some examples, the first mechanism utilizes one or more
components such as screws, threads, and mechanical positioning.
Other examples are possible.
[0130] In some approaches, the optical apparatus may further
include a locking mechanism which prevents the first mechanism from
further adjusting an optical property of the deformable lens. In
other approaches, one or more elements of the locking mechanism may
involve at least one of a process such as application of adhesive,
welding, clamping and heat staking.
[0131] In some aspects, the first mechanism is removable from the
housing. In other aspects, the deformable lens is at least
partially defined by a container. In still other aspects,
deformation of the deformable lens causes a change in the optical
property of the deformable lens.
[0132] In other aspects, the first mechanism changes a position of
the lens shaper with respect to the container which causes the
deformable lens to deform, thereby changing the optical property of
the deformable lens. In other examples, the optical apparatus
further includes a membrane and the first mechanism acts to change
an initial tension of at least a portion of the membrane.
[0133] In still others of these embodiments, an optical apparatus
includes a displacement mechanism, a container, and a lens shaper.
The container at least partially encloses a filler material and the
filler material at least partially defines a plurality of
deformable lenses. The displacement mechanism is capable of
changing an optical property of at least one of the plurality of
deformable lenses.
[0134] In other examples, the apparatus further includes a membrane
and the membrane at least partially encloses the filler material.
In other examples, the apparatus further includes at least one
light source which interacts with at least one of the plurality of
deformable lenses. The light source is an element such as a light
emitting diode, a laser, a halogen lamp, or a discharge lamp. In
still other examples, the apparatus further includes a reflector in
communication with one or more of the plurality of deformable
lenses. The optical apparatus may be used for illumination
purposes.
[0135] In others of these embodiments, an optical apparatus
includes a light source and a reflector. The light source emits
light rays and the reflector redirects parts of the light rays
emitted by the light source onto a deformable lens, which receives
both light rays directly emitted by the light source, and also
receives the light rays redirected by the reflector. An actuation
mechanism is coupled to the deformable lens and is operative to
cause a deformation of the deformable lens, causing a change in the
optical properties of the optical apparatus.
[0136] In some aspects, the deformable lens is constructed from at
least one material such as a gel and a polymer. Other examples are
possible. In other aspects, the light source is an element such as
a light emitting diode, a laser, a halogen lamp, and a discharge
lamp. Other examples of light sources are possible. In still other
examples, the reflector is an element such as a free-form metal,
mirror, free-form plastic. Other examples of reflectors are
possible. In other examples, the optical apparatus further includes
at least one rigid optical element such as a filter, a lens, a
diffuser, a grating, a micro-structure, and a mirror.
[0137] In other aspects, the deformation of the deformable lens is
caused by a movement of the rigid optical element towards the light
source. In still other aspects, the deformation of the deformable
lens is caused by a displacement of a lens shaper.
[0138] In some examples, the deformable lens is constructed from a
first deformable material which is at least partially surrounded by
a deformable membrane. In some approaches, the first deformable
material is at least one material such as gas, liquid, ionic
liquid, gel, and polymer.
[0139] The actuation mechanism may include a variety of different
mechanisms. For example, the actuation mechanism may be a manual or
an electromechanical mechanism.
[0140] In some examples, the deformable lens is coupled to the
reflector. In other examples, a plurality of optical apparatuses
may be arranged so as to form an optical system (e.g., a system for
illumination).
[0141] In still others of these embodiments, an optical apparatus
includes a first deformable lens, a first reservoir, a first
container, a second deformable lens, a second reservoir, a second
container, and an electromechanical actuation device. The first
reservoir is in communication with the first deformable lens by
means of a first filler material. The first container at least
partially encloses the filler material within the first deformable
lens and the first reservoir. The second reservoir is in
communication with the second deformable lens by means of a second
filler material. The second container at least partially encloses
the filler material within the second deformable lens and the
second reservoir. The electromechanical actuation device is
operative in a plurality of directions and at least one direction
of the electromechanical actuation device is operative to change
one optical property of the first deformable lens. The second
direction of the electromechanical actuation device is operative to
change one optical property of the second deformable lens.
[0142] In still others of these embodiments, an optical apparatus
includes a deformable lens, a lens shaper, a support member, and a
membrane. The lens shaper at least partially defines a shape of the
deformable lens. The lens shaper and the support member clamp the
membrane such that the membrane is always (or substantially always)
in contact with the lens shaper. The deformable lens can have a
convex or a concave shape, and the lens shaper and the support
member are stationary with respect to each other.
[0143] In yet others of these embodiments, an optical apparatus
includes a lens shaper, a support member, and a membrane. The lens
shaper surrounds an opening in the lens assembly and has an inner
ring portion and an outer portion, the inner ring portion extending
from the outer portion in a generally axial direction. The membrane
is generally disposed between the lens shaper and the support
member. The membrane is flexible and deforms across the opening in
the optical apparatus. The membrane has a radius that varies based
upon the shape of the membrane, and the radius is selectively
adjustable. The membrane radially extends from the opening so as to
be in contact with the inner ring portion of the lens shaper.
[0144] In still others of these embodiments, an optical apparatus
includes a deformable lens, a lens shaper, and a first detachment
point. The deformable lens defines at least by a first membrane and
a filler material. The deformable lens is in contact with the lens
shaper at a contact region, and not in contact with the lens shaper
at a non-contact region. The first detachment point is defined as
the interface between the contact region and the non-contact
region. The first detachment point defines a diameter of the
deformable lens. The shape of the lens shaper allows for a location
of the first detachment point to vary with deformation of the
deformable lens, such that the diameter of the deformable lens
varies with the location of the first detachment point. In some
examples, an axial position of the detachment point varies with the
deformation of the deformable lens.
[0145] In others of these examples, the optical apparatus further
includes a first support member; a second membrane which is a
subset of the first membrane that is in contact with the lens
shaper at the contact region; a third membrane which is connected
with an end of the second membrane and the first support member; a
second detachment point which is located at a connection point
between the second membrane and the third membrane; a first
theoretical line which is tangent to the lens shaper at the first
detachment point and a second theoretical line which is tangent to
the lens shaper at the second detachment point; and a connection
angle defined as an angle between the first theoretical line and
the second theoretical line and is a supplementary angle to an
angle that contains a majority of the lens shaper. A connection
angle positive sense is defined as being in a direction from the
second theoretical line through the first theoretical line and
towards the lens shaper wherein the connection angle does not span
across the lens shaper. The absolute value of the connection angle
is between 0 and 180 degrees.
[0146] In some examples, only frictional forces are used to hold
the first membrane to the lens shaper.
[0147] In still other examples, the apparatus further includes a
second lens shaper, and a third lens shaper. Deformation of the
deformable lens causes the lens shaper to shift from the second
lens shaper to the third lens shaper and changes the diameter of
the deformable lens.
[0148] In still other examples, the optical apparatus further
includes a second lens shaper and a third lens shaper. Deformation
of the deformable lens causes the detachment point to shift from
the second lens shaper to the third lens shaper and changes an
axial position of the deformable lens.
[0149] In still others of these embodiments, an optical apparatus
includes a deformable lens, a lens shaper, and an actuation device.
The deformable lens is capable of assuming a plurality of shapes.
The lens shaper at least partially defines a shape of the
deformable lens. The actuation device is capable of changing at
least one optical property of the deformable lens. An inner surface
of the lens shaper extends from a first face and has a first
perimeter having a first shape and extends to a second face having
a second perimeter having a second shape. The first shape and the
second shape are different. The shape of the deformable lens can be
defined by the first face of the lens shaper or the second
face.
[0150] In some examples, the first face of the lens shaper is
substantially circular and the second face of the lens shaper is
substantially non-circular. In other examples, the first face of
the lens shaper is substantially non-circular and the second face
of the lens shaper is substantially non-circular.
[0151] The approaches described herein can be used to form various
types of lens assemblies having any number of lenses or other
optical components used in any combination. For example, any number
of the tunable lenses described herein can be used in conjunction
with other optical elements or lenses to form any type of lens
assembly to achieve any optical purpose or function. Additionally,
the assembly may be combined with other focus tunable and non-focus
tunable lenses, filters and any other combination of optical
systems, including mirrors, gratings, prisms, shutters, image
stabilizers and apertures. Any of the tunable or focus adjustable
lenses described herein can be incorporated into a system according
to any approach described in the application entitled "Zoom Lens
System and Method" having attorney docket number 97373 and filed on
the same day as the present application, the contents of which are
incorporated herein in their entirety.
[0152] Referring now to the figures and particularly FIGS. 1a and
1b, one example of a lens assembly 100 is described. The lens
assembly 100 includes a flux guiding structure 102, a magnet 104, a
plastic holder 106, an optical membrane 108, a coil 110 (disposed
in a chamber 107), a bottom plate 112 (e.g., a glass plate), and a
vent 114. The assembly forms a central opening 118, which is filled
with air. A cover (e.g., a glass cover and not shown) may be placed
on the top of the assembly to protect the internal components from
debris and/or provide other optical functions. The central opening
118 extends in an axial direction (in the direction of the z-axis)
through the assembly 100. Light rays 152 representative of an image
move through the central opening 118 in the lens structure in the
axial direction. Once acted on by the components of the lens
structure, a sensor 150 (e.g., a charged coupled device (CCD)) or
CMOS device receives and senses the image.
[0153] As described elsewhere herein, the flux guiding structure
102 provides a path for magnetic flux provided by the permanent
magnet 104 created by excitation of the coil 110. The flux guiding
structure 102 may be composed of any suitable paramagnetic material
such as metal and in particular iron. More specifically, a
magnetically soft iron, steel, or Ni--Fe material may be used.
Other examples of metals and other compositions of materials are
possible.
[0154] The optical membrane 108 and bottom plate 112 form and
define a lens and a reservoir 116. Different filler materials
(e.g., fluid, gas, gel, or other materials) can be used to fill the
reservoir 116. The refractive indexes of the filler materials used
to fill the reservoir 116 may also vary. In one example, a fluid is
used as the filler material and the refractive index of the fluid
in the reservoir 116 is selected to be different from the
refractive index of the air in the opening 118. The bottom plate
112 may be constructed from glass and provide optical correction
functions. Also, the plate 112 may prevent debris from entering the
assembly 100.
[0155] The optical membrane 108 separating the upper and lower part
of the lens is made of flexible material. The central section of
the membrane and the actuator (torus) section (where the coil 110
is attached) may be made of the same membrane material. However, in
other examples the actuator section of the membrane and the
central/optical section are constructed of different membrane
materials. The properties of the membrane and/or the filler
materials (e.g., an optical fluid) combine to provide reflective,
refractive, diffractive, and absorptive, and/or color filtering
functions. Other functions may also be provided by the membrane 108
and/or the filler material in the reservoir 116. An optional top
plate (not shown) may be used to cover the top of the assembly
100.
[0156] The coil 110 is any wound wire coil structure and can be
configured in a variety of different ways. For example, the coil
110 may be a single coil or a double coil. The wire in the coil 110
may also be of any suitable gauge or diameter. The coil 110 may be
attached to the membrane with any type of adhesive or fastener
(e.g., glue).
[0157] The magnet 104 is any suitable permanent magnet that is
polarized in a direction that creates the desired flux flow. For
example, the magnet 104 may be magnetized in an axial angle of zero
degrees with respect to the optical axis. Other magnetization or
polarizations and angular directions for the magnetization of the
magnet 104 may be provided. The magnet 104 may be a single
ring-shaped magnet or alternatively, be constructed from several
segments.
[0158] The holder 106 may be composed of any suitable material. In
one example, it is constructed of a plastic (e.g., the holder may
be a plastic or the like). The holder 106 supports some or all of
the remaining members of the assembly 100.
[0159] As mentioned, the shape of the overall lens (e.g., including
the membrane 108 and reservoir 116) can be varied depending upon
the optical function desired. For example, spherical lenses (e.g.,
convex and concave), aspherical lenses (e.g., convex and concave),
cylindrical lenses (e.g., defined by a square housing instead of
round), flat lenses, micro lenses (e.g. a micro lens array or a
diffraction grating), and lenses which include an antireflection
coating (e.g., a nano structure) that are integrated or attached to
the optically active section of the lens can be provided. Other
types of lenses are possible.
[0160] In the example of FIGS. 1a and 1b, the filler material
(e.g., an optical fluid) is retained in the reservoir 116 on one
side by the flexible membrane 108 and on the other side by a rigid
material, for example, by a plate 112 (e.g., a correction glass
plate). However, in other examples, both sides of the reservoir are
encased by a separate membrane (i.e., two flexible membranes and
one motor structure).
[0161] The vents 114 allow air to flow in and out of the chamber
107 as the coil 110 moves within the chamber. To take one example,
as the coil 110 moves downward, air enters the chamber 107 and as
the coil moves upward, air exits the chamber 107.
[0162] The assembly 100 may be stacked in any combination with the
above-described focus tunable lens, such as, for example, with
other focus tunable and non-focus tunable lenses, filters and any
other combination of optical systems, including mirrors, gratings,
prisms, and apertures. The assembly 100 be used with or include
other elements as well.
[0163] In one example of the operation of the system of FIGS. 1a
and 1b, application of a current through the coil 110 results in a
movement of the coil 110 (e.g., up or down, depending on the
direction of the current). The amount and direction of current
provided may be controlled by any number of devices or approaches.
For example, a user may manually press a switch, button, or other
actuator to control current flow. In another example, current flow
may be controlled by a program or algorithm (e.g., an autofocus or
zoom program or algorithm), which adjusts automatically the current
flow supplied to the coil 110.
[0164] More specifically, in FIG. 1a, the current is zero amperes
and the coil is in a first position. Referring now to FIG. 1b,
current is applied to the coil 110 and the resultant interaction of
the current and the magnetic field of the magnet 104 creates an
electromotive force that moves the coil 110 from the first position
to a second position in an axial direction (along the z-axis).
Movement of the coil 110 to the second position pushes the membrane
108 and this pressing of the membrane 108 displaces the filler
material (e.g., optical fluid) in the reservoir and moves the
membrane 108 from a first position (as shown in FIG. 1A) to a
second position (as shown in FIG. 1B). Consequently, the shape of
the lens section (e.g., the membrane 108 and the plate 112 and the
filler material) changes. Changing the shape of the lens alters the
optical properties of the lens. Inhomogeneous material thickness or
hardness for the membrane 108 may also be used to alter the optical
properties of the lens.
[0165] Referring now to FIGS. 2a and 2b, another example of a lens
assembly 200 is described. The lens assembly 200 includes a flux
guiding structure 202, a first magnet 204, a second magnet 205, a
membrane 208, a coil 210 (disposed in a chamber 207), a bottom
plate 212 (e.g., a glass or polycarbonate plate), a top plate 213
(e.g., a glass plate), and vents 214 and 215. The top plate 213 and
membrane 208 define a first reservoir 218 and the bottom plate 212
and membrane 208 form a second reservoir 216. Each of the
reservoirs 216 and 218 are filled with a filler material such as a
liquid, gel, or some other filler material. A support structure
(e.g., a plastic component and not shown in FIGS. 2a and 2b) may
support all or some of the elements of the assembly 200. The vents
214 allow air to flow in and out of the chamber 207 as the coil 210
moves within the chamber 207. A central opening 230 extends in an
axial direction (in the direction of the z-axis) through the
assembly 200. Light rays 252 representative of an image move
through the central opening 230 in the lens structure in the axial
direction. Once acted on by the components of the lens structure, a
sensor 250 (e.g., a charge coupled device (CCD)) receives and
senses the image.
[0166] In this example, the coil 210 is attached on both sides of
the membrane 208. Attachment may be made by any adhesive or
fastener arrangement (e.g., glue). This allows, for example, an
operation that requires merely pushing on the membrane 208 rather
than pulling the membrane, to thereby shift or tune the lens from a
convex shape to a concave shape. Accordingly, the support structure
(e.g., the bobbin) may not need to be glued or otherwise attached
onto the membrane 208. To prevent gravitational effects, both sides
of the reservoirs 216 and 218 are filled with a filler material
(e.g., liquids) having similar densities, but with different
indices of refraction.
[0167] As described elsewhere herein, the flux guiding structure
202 provides a path for magnetic flux created by the permanent
magnet and interacting with the magnetic fields of the coils 210.
The flux guiding structure 202 may be composed of any suitable
metal such as iron. Other examples of magnetically soft materials
or other compositions are possible.
[0168] In the example of FIG. 2A and FIG. 2B, the optical membrane
208 separates the upper and lower part of the lens is made of
flexible material. The central section of the membrane 208 and the
actuator (torus) section (where the coil 210 is attached) may be
made of one membrane material. However, in other examples the
actuator section of the membrane and the central/optical section
are constructed of different membrane materials. As with the
example of FIG. 1A and FIG. 1B, the membrane or the filler material
(e.g., an optical fluid) can combine to provide various reflective,
refractive, diffractive, and absorptive, or color filtering
properties for the system. Other properties may also be
provided.
[0169] The coil 210 is any wound wire coil and can be configured in
a variety of different ways. For example, the coil 210 may be a
single coil or a double coil. Additionally, the wire in the coil
210 may be of any suitable gauge or diameter. The magnets 204 and
205 are any suitable permanent magnets that are polarized in a
direction that creates the desired flux flow (e.g., the magnets may
be radially or axially polarized).
[0170] The holder (not shown) may be composed of any suitable
material. As mentioned, the holder may be a plastic part or similar
arrangement. In one example, it is constructed of a plastic. The
holder supports some or all of the remaining members of the
assembly.
[0171] The shape of the lens (e.g., the relative positioning of the
membrane 208 with respect to each of the reservoirs 216 and 218)
can be varied. For example, spherical lenses (e.g., convex and
concave), aspherical lenses (e.g., convex and concave), cylindrical
lenses (e.g., defined by a square housing instead of round), flat
lenses, and any micro lenses (e.g., a micro lens array or a
diffraction grating), and lenses including antireflection coating
(e.g., nano structure), which can be integrated or attached to the
optically active section of the lens can be created. Other examples
are also possible.
[0172] In the example of FIGS. 2A and 2B, the membrane 208
separates the reservoirs 216 and 218. Plates 212 and 213 enclose
the other sides of the reservoirs 216 and 218. The plates 212 and
213 may be constructed from glass and provide optical correction
functions. Also, the plates 212 and 213 may prevent debris from
entering the assembly 200 when an air gap is on the other side of
the plate.
[0173] The assembly 200 may be stacked in any combination with the
above-described focus tunable lens, such as, for example, with
other focus tunable and non-focus tunable lenses, filters and any
other combination of optical systems, including mirrors, gratings,
prisms, and apertures. The assembly 200 can be used with other
elements as well.
[0174] In one example of the operation of the system of FIGS. 2A
and 2B, application of a current through the coil 210 results in a
movement of the coil 210 (e.g., up or down, depending on the
direction of the current). The amount and direction of current
provided may be controlled by any number of devices or approaches.
For example, a user may manually press a switch, button, or other
actuator to control current flow. In another example, current flow
may be controlled by a program or algorithm (e.g., an autofocus or
zoom program or algorithm), which adjusts automatically the current
flow supplied to the coil.
[0175] More specifically, in FIG. 2A, the current is zero amperes
and the coil is in a first position and membrane 208 is also in a
first position. Referring now to FIG. 2B, current is applied to the
coil 210. The current interacts with the magnetic flux created by
the magnets 204 and 205 and the flux guiding structures and the
resultant electromotive force moves the coil 210 from the first
position to a second position in an axial direction along the
z-axis. Movement of the coil 210 to the second position pushes the
membrane 208 and this pushing of the membrane 208 displaces the
filler material in the reservoirs 216 and 218 such that the
membrane 208 moves upward. This movement alters the optical
properties of the lens since the relative shapes of the first
reservoir 216, second reservoir 218, and membrane 208 are changed.
Inhomogeneous material thickness or hardness for the membrane 208
may also be used to alter the optical properties of the lens.
[0176] Referring now to FIG. 3, another example of a lens assembly
300 is described. The lens assembly 300 includes a flux guiding
structure 302, a first magnet 304, a second magnet 305, a holder
306, a first membrane 308, a second membrane 309, a first coil 310
(disposed in a chamber 327), a second coil 311 (disposed in a
second chamber 328) a top plate 312, a first vent 314, and a second
vent 315. A chamber 316 is formed between the top plate 312 (e.g.,
a glass plate) and the first membrane 308 and is filled with air. A
reservoir 318 is formed between the first membrane 308 and the
second membrane 309 and is filled with a filler material. A second
opening 313 extends at the bottom of the assembly and is filled
with air. A central opening 330 extends in an axial direction (in
the direction of the z-axis) through the assembly 300. Light rays
352 representative of an image move through the central opening 330
in the lens structure in the axial direction. Once acted on by the
components of the lens structure, a sensor 350 (e.g., a charge
coupled device (CCD)) receives and senses the image.
[0177] The vents 314 and 315 allow air to flow in and out of
chambers 327 and 328, and the coils 310 and 311 move within these
chambers. To take one example, as the coil 310 moves downward, air
enters the chamber 327 and as the coil moves upward, air exits the
chamber 327.
[0178] The plate 312 may be constructed from glass and provide
optical correction functions. Also, the plate 312 may prevent
debris from entering the assembly 300.
[0179] In this example, two motors are used. More specifically,
both sides of the lens (e.g., the first membrane 308, reservoir
318, and second membrane 309) are deformed using a separate motor
positioned on each side of this lens. When one of the chamber 316
or the opening 313 (when this opening is sealed with a cover or
plate) is air-tight sealed, then both of the lens sides (i.e., the
membranes 308 and 309) can be deformed independently of each
other.
[0180] The flux guiding structure 302 provides a path for magnetic
flux created by the first magnet 304 and the second magnet 305. The
flux guiding structure 302 may be composed of any suitable
magnetically soft material such as iron. Other examples of metals
or other compositions are also possible.
[0181] The optical membrane 308 and 309 separating the upper and
lower part made of flexible materials. The central section of the
membrane and the actuator (torus) section (where the coils 310 or
311 is attached) may be made of one membrane material. However, in
other examples the actuator section of the membrane and the
central/optical section are constructed of different membrane
materials. As described elsewhere herein the membrane 308, membrane
309 and/or reservoir 318 can provide various reflective,
refractive, diffractive, and absorptive, or color filtering
functions for the overall system. Other examples of functions may
be provided as well.
[0182] The coils 310 and 311 are any wound wire coils and can be
configured in a variety of different ways. For example, the coil
310 or 311 may be a single coil or a double coil. The wire in the
coils 310 and 311 may be of any suitable gauge or diameter. The
wire could also be rectangular or hexagonal for improved packing
density. The magnets 304 and 305 are any suitable magnet that is
polarized in a direction that creates the desired flux flow.
[0183] The holder 306 may be composed of any suitable material. In
one example, it is a component that is constructed of a plastic.
The holder 306 supports some or all of the remaining members of the
assembly.
[0184] The shape of the lens (e.g., the membrane 308, 309 and the
reservoir 318) can be varied to produce various types of lenses.
For example, spherical lenses (e.g., convex and concave),
aspherical lenses (e.g., convex and concave), cylindrical lenses
(e.g., defined by a square housing instead of round), flat lenses,
micro lenses (e.g. micro lens array, diffraction grating), and
lenses including antireflection coatings (e.g., nano structures)
that can be integrated or attached to the optically active section
of the lens can be created. Other examples of lens structures are
possible. Inhomogeneous material thickness or hardness for the
membrane 308 may also be used to alter the optical properties of
the lens.
[0185] As shown in FIG. 3, the membranes 308 and 309 constrain the
filler material in the reservoir 318. The top cover provides an
air-tight seal for the chamber 316. A bottom cover (not shown) may
also seal the opening 313.
[0186] The assembly 300 may be stacked in any combination with the
above-described focus tunable lens, such as, for example, with
other focus tunable and non-focus tunable lenses, filters and any
other combination of optical systems, including mirrors, gratings,
prisms, and apertures. The assembly 300 may be used with other
elements as well.
[0187] In one example of the operation of the system of FIG. 3,
electric current can be applied to one or both of the coils 310 and
311. The amount and direction of current provided may be controlled
by any number of devices or approaches. For example, a user may
manually press a switch, button, or other actuator to control
current flow. In another example, current flow may be controlled by
a program or algorithm (e.g., an autofocus program), which adjusts
automatically the current flow supplied to the coil. The
interaction of the current with the magnetic field of the magnets
creates an electromotive force that moves one or both of the coils
in an axial direction along the z-axis. Movement of the coils 310
and/or 311 displaces the filler material (e.g., optical fluid) in
the reservoir 318, thereby altering the overall lens shape. Since
the chamber 316 is sealed, movement of each of the membranes 308
and 309 can be independently controlled.
[0188] The membranes as described herein can be produced by using
various methods and manufacturing techniques. For example, the
membranes can be formed using knife coating, curtain coating,
calendaring, injection molding, nano-imprinting, sputtering, hot
embossing, casting, spin-coating, spraying, and/or chemical
self-assembly techniques. Other examples are possible.
[0189] The membranes can also be constructed from various
materials. For example, the membranes can be constructed from gels
(for example, Optical Gel OG-1001 by Litway); polymers (e.g., PDMS
Sylgard 186 by Dow Corning, or Neukasil RTV 25); acrylic materials
(e.g. VHB 4910 by the 3M Company); polyurethane; and/or elastomers
to name a few examples. In many of these examples, the membranes
are constructed from a permeable material through which air (but
not liquids or gels) can pass. Other examples are possible.
[0190] Additionally, in some examples, the membranes are
pre-stretched. This technique may provide an improved optical
quality and faster response in movement or deformation of the
membrane. For example, the membrane may be mounted in a
prestretched manner under elastic tension. The membrane may be
stretched in stages such that the elastic tension of the inner area
of the membrane is less than the tension in the outer area of the
membrane. In other embodiments, prestretching is not used.
[0191] Referring now to FIGS. 4 and 5, one example of an approach
for forming a lens assembly is described. At step 502 (FIG. 4a), a
housing is provided. The housing may include a flux guiding
structure and a plastic holder to name two example elements.
Generally speaking, material choices for the parts of the lens
assemblies described herein can be selected to minimize frictional
forces between the moving parts of the lens assemblies described
herein. For example, durable plastics may be used.
[0192] At step 504 (FIG. 4b), the membrane is coupled or connected
to the housing. The membrane can have a flexible anti-reflective
coating having, for example, a nanostructure molded in a flexible
material integrated or attached to the lens defining membrane. The
coating can have a thin layer of nanoparticles (e.g., SiO2
particles evenly distributed on a thin layer on the membrane).
Other coatings are also contemplated which are known to those
skilled in the art.
[0193] At step 506 (FIG. 4c) the structure is flipped upside down
and a vacuum is drawn. A fluid (e.g., oil) is then applied over the
membrane. The fluid can be applied by various methods. For
instance, ink-jetting, dispensing, pumping, and/or dosing may be
used. Other approaches are also contemplated which are known to
those skilled in the art.
[0194] At step 508 (FIG. 4d) a cover (e.g., a glass cover) is
coupled to the housing. The coupling may be made by glue or some
other adhesive or fastener (e.g., screw, snap connectors,
ultrasonic welding, hot melting, or the like). The cover, which is
in the optical path of the lens can be, for example, reflective,
diffractive, transparent, absorptive, refractive or a color-filter
glass. It can also take any shape, including but not limited to,
prisms, lenses, or micro or nanostructures, including
anti-reflective, anti-scratch, and anti-glare coating. Other
examples are possible.
[0195] At step 510 (FIG. 4e), the housing is again reversed
(flipped over) and air bubbles appear at the top. At step 512 (FIG.
4f), the air penetrates the membrane leaving a reservoir free or
substantially free from air bubbles through diffusion. The fluid
chamber can be sealed by various methods, such as, for example,
heat melting, gluing, chemical cross-linking, ultrasonic welding,
and/or clamping. Other sealing approaches are also contemplated
which are known to those skilled in the art.
[0196] Referring now to FIGS. 6-8, an example of a lens assembly
600 is described. The lens assembly 600 includes a first bobbin 601
(e.g., an L-shaped bobbin), a second bobbin 602 (e.g., an L-shaped
bobbin), a first coil 604, a second coil 605, magnets 606, an outer
case return structure 608, a central core 610, a metal cylinder
612, (appearing as a pole in the cross-sectional view) a first
fluid lens 613, a second fluid lens 614, a fixed lens 616, aperture
portions 618, and lens attach points 620. A separate image sensor
650 receives images through the assembly 600. Attachments to the
sensor 650 (e.g., a CCD sensor) and a top cover and further
corrective optical elements are not shown in these examples.
[0197] The lens aperture portions 618 include an opening and are
fixed in all directions and are defined at least in part by the
flux guiding structure. In this example, the plastic holds
everything and the flux guiding structure is embedded in the
plastic. This approach results in much higher optical quality than
for structures that have a moving magnet or coil which are defining
the boundary of the lens. The improved optical quality is due at
least in part to the use of a single part to define most or all of
the tolerancing structures. In addition, optical quality strongly
relies on the accuracy of the lateral placement of the lens.
[0198] The bobbins 601 and 602 may be any structures that hold some
or all of the other assembly elements in place. The coils 604 and
605 are any electrical coils that are constructed from wound wire.
The coils 604 and 605 may be constructed from, for example, wires
wound around a portion of the bobbins, or be a chip-inductor
fabricated coil. Other examples of coils are possible. The bobbins
601 and 602 are also moved to deform the lenses.
[0199] The magnets 606 are any permanent magnets that are polarized
in any suitable direction (e.g., a radial direction). The metal
cylinder 612 and outer case return structure 608 provide a flux
guiding structure that may be constructed from metals or other
paramagnetic/magnetically soft materials. This structure provides a
flux path that acts to develop an electromotive force that moves
the coils. This flux guiding structure may be created using insert
molding techniques to name one approach. Other construction
techniques can also be used. Thus, in this example, two independent
coils are disposed in the same motor structure.
[0200] As mentioned, two independent coils 604 and 605 are used
and, when excited, move the bobbins 601 and 602. Movement of the
bobbins 601 and 602 changes the shape and optical properties of the
lenses at the top or bottom of the assembly. For example, the
lenses 613 and 614 may be defined by membranes and fixed plates and
movement of the bobbins moves or displaces the filler material in
the reservoirs as described elsewhere herein. The two focus tunable
lenses 613 and 614 are used to achieve an optical zoom effect. When
the properties of one of the lenses 613 or 614 are changed, then
the other lens is adjusted, to focus the image back onto the image
sensor. Therefore, either of the individual tunable lenses can be
used as autofocus and/or zoom lens. The fixed lens 616 may be
constructed of glass or plastic (or other suitable material) and is
a divergent lens that is used to reduce the height of the assembly
while still being able to illuminate the entire or substantially
the entire sensor 650.
[0201] The central core 610 of the assembly 600 may be molded from
plastic or other suitable material and be a fixture that provides
support for the membranes or other system components. The central
core 610 also defines the location of all optical parts. For
example, the central core 610 defines the position of the fluid
lens 614 and the fixed lens 616. The central core 610 may also
include all or part of the flux guiding structure. The examples of
FIGS. 6-8 include focusing lenses (lens 613) and a zoom lens (lens
614). A single motor structure is provided.
[0202] A plate (e.g., a glass plate, not shown) may be placed on
top of the structure. Thus, moving from top of the assembly
downward, are a first fluid lens system (i.e., the plate, a fluid
reservoir, and membrane) and the bobbin. A similar fluid lens
system is disposed at the bottom of assembly. As the coils 604 and
605 are excited, they move the bobbins 601 and 602 and thereby
adjust the optical properties of the system.
[0203] In this example, all fixturing and optical features are
placed in the central core 610. Consequently, the number and
complexity of the parts needed to construct the assembly are
minimized. In some examples, the main cost of the assembly is
determined by the tolerance of the lens attach circles, apertures,
corrected lenses, meniscus lens, other optical elements, and charge
coupled device (CCD) sensor placement.
[0204] The examples shown with respect to FIGS. 6-8 include an
inverted top lens. In this case, the top lens falls downward
towards a sensor instead of outward to the object. Upward force of
the bobbin produces a downward movement of the lens and downward
force produces a downward upward movement. This placement may yield
space, cost, and magnetic effect advantages. However, in other
approaches the fluid reservoir faces upward towards the object. In
this case, downward force of the coil/bobbin produces an upward
force on the lens (see, e.g., FIGS. 1A and 1B).
[0205] As shown in FIG. 7, the outer portion of the assembly
includes a ring 622 that is an attachment point for the upper
membrane of the upper lens. The ring 622 is disposed around the
molded central core 610.
[0206] Referring now to FIG. 8, one example of a desired magnetic
flux pattern directed by the flux guiding structure is shown. This
structure is for an eight-magnet structure but can be changed to a
four-magnet structure and the guiding structure would be suitably
modified. The structure could also be an axial magnetized structure
with two plates. Cylinder 612 could be bent and the inside portion
(shown as a pole in these figures) moved inward. Moving the
cylinder 612 away into the corners of the assembly allows for the
use of insert molded connectors that could protrude from the bottom
and make circuit connections.
[0207] The central core 610 contains most of the fixturing for the
entire assembly and the outer clamping structure also serves as a
flux guiding structure. The central core 610 contains the bottom
aperture. Fixtures for corrective lens structure also are formed in
the aperture. The central core 610 may contain structures having
inserts for pole piece magnetic structure, high precision lens
defining structures, wire routing for voice coil lead out wire,
insert molding for pins for out of the unit connection to circuit
board, to name a few examples.
[0208] As shown in FIG. 8, flux lines 630 are formed and directed
as shown. The flux lines 630 are formed in a direction
perpendicular to the z-axis (axial direction) and through the coil.
This selected direction of the flux through the coil creates the
desired (and maximizes) and available electromotive force needed to
move the coil.
[0209] Referring now to FIG. 9, another example of a lens assembly
is described. A ring structure 902 (e.g., lip) defines the lens
(e.g., the membrane 904, filler material, container, etc.). The
ring structure 902 affects the concentrity, flatness, parallelism,
circularity, and surface finish of the membrane 904 and hence the
optical properties of the lens. As with the examples discussed
elsewhere herein, a flux guiding structure 911 (the structure that
guides the magnetic flux for the magnet) can be disposed in several
different portions of the assembly depending upon the desired
outcome.
[0210] The assembly includes magnets 906, a first coil 908, a
second coil 910, a cylindrical metal piece 912, a first bobbin 914
and a second bobbin 918. The example of FIG. 9 operates in a
similar way as the examples of FIG. 6-8 except that one of the
bobbins pushes upward while the other bobbin pushes downward.
[0211] Referring now to FIG. 10, another example of a lens assembly
1000 is described. This example has similar components that have
been described with respect to the other examples herein. However,
in this example, the flux guiding structure is utilized to define
the lens shaping points. The example of FIG. 10 is a push-pull
example where the membrane is both pushed and pulled. An
axially-polarized magnet is also used.
[0212] The assembly 1000 includes a flux guiding structure 1002, a
magnet 1004, a coil 1006, and a top plate 1008. Indexing portion
1001 for an optional top cover is also provided, and membrane
contact points 1010 for a membrane (not shown) are attached to the
coil and the flux guiding structure 1002. The operation of the
assembly 1000 in moving the membrane is accomplished similarly to
the examples of FIG. 1A and FIG. 1B.
[0213] Referring now to FIGS. 11-16, a lens assembly 1100 is shown
where the magnets are disposed at the corners of the flux guiding
structure and polarized in a radial direction. It will be
appreciated that like numbers in these figures refer to like
elements (e.g., element 1116 in FIG. 11 is the same as element 1216
in FIG. 12 and so forth). This example may reduce the overall
height and/or diameter of the lens and be particularly advantageous
for applications that require a compact size. Additionally, this
example is configurable to be coupled to image sensors that are
square (or rectangular) in cross-sectional shape.
[0214] The assembly 1100 includes a flux guiding structure 1102, a
coil 1104, a first magnet 1116, a second magnet 1118, a third
magnet 1120, a fourth magnet 1122, a bobbin 1106, flexible contacts
1128, and a reservoir 1108 formed between a membrane 1110 and a
plate 1112. A lens shaper sleeve 1114 secures and defines the
membrane 1110. A control element 1124 is used to control the
current in the coil 1104. As mentioned previously, the control of
element 1124 may be any actuator (e.g., a button, switch, knob or
the like) manually adjusted by the user or a control program (e.g.,
an autofocus or zoom algorithm) that automatically adjusts the
current based upon, for example, properties of the received image.
Different control elements can be provided to control different
lenses.
[0215] The placement of the magnets at the corners of the assembly
1100 can be done by using self-alignment of the magnetized magnets
into the flux guiding structure. This could also be done manually
and magnetized later. The positioning of the magnets 1116, 1118,
1120, and 1122 at the corners also provides more freedom for
guiding the coil wires out of the housing. In particular, it is
possible to lead the wires out of the housing on the side of the
housing where no magnets are present. Slits can be formed on the
flat side of the housing to provide for ventilation. To account for
the movement of the coil, it is possible to either connect the coil
wire to a flexible spring contact, which is guided outside.
Alternatively, in another example, the flexibility of the coil wire
can be used to guide the wire to a fixed electrical contact
integrated into the housing of the lens, as seen in FIG. 16.
[0216] The shapes and configuration of components of any of the
examples used herein may also vary. In addition, in the examples of
FIGS. 11-16 two oppositely polarized magnets can be used in each of
the four corners eliminating the need for at least some portions or
even the vast majority of the flux guiding structure.
Anti-reflective (AR) coatings may be used on various structures of
the assembly to reduce reflection of light as it passes through the
assembly.
[0217] Matching the bobbin shape to the fluid retaining structure
may be performed. Matching the shape benefits or reduces overall
part size, improves shock performance, and reduces the total force
needed to move the structure.
[0218] By using a generally square-shaped bobbin, the axial
displacement of the bobbin can be reduced to approximately 10% of
the diameter of the optical active lens portion defined by the lens
shaper sleeve 1114. This may prove advantageous, when, for example,
a lens deformation from approximately 10% of the lens radius to
approximately 70% of the lens radius is required.
[0219] As shown, the first magnet 1116, second magnet 1118, third
magnet 1120, and fourth magnet 1122 are in the corners of the
assembly and the magnet is magnetized radially inward in the
direction of arrows 1330. Also, as shown, the wires of coils are
directly bonded to the flexible metal contact connected to the
plastic bobbin. This prevents a complex attachment of the wire
after it is taken from the coil winding machine.
[0220] As mentioned, the voice coil motor structure provided has
four triangular magnets in the corners. Such a design reduces
height, width, and length of the assembly. Height is reduced
because thick plates can be avoided. The rectangular design allows
matching to a sensor that is rectangular in shape. The lens shaper
sleeve 1114 allows the reduction of the tolerances on the metal
return structure, while maintaining accuracy for the lens defining
structure. This reduces the manufacturing costs for the assembly.
As shown in FIGS. 15-16, alternative coil connection approaches can
be employed utilizing the flexibility of the coil wire to make
electrical connections to an electrical conductor.
[0221] Referring now to FIGS. 17a and 17b, another example of a
lens assembly 1700 is described. The assembly includes and upper
flexible lens 1702, a bi-concave lens 1704, a lower flexible lens
1706, and an infrared (IR) filter 1708. A spacer 1710 separates
different portions of the assembly 1700.
[0222] The assembly 1700 can utilize any combination of individual
tunable lenses (e.g., the lenses 1702 and 1706) consisting of at
least one focus tunable lens (e.g., for autofocus) or multiple
lenses (e.g., with a possible zoom feature) in combination with
other focus tunable lenses or other hard optical elements such as,
for example, lenses, filters, diffusers, optical apertures and
other examples. The stacking of lenses in a lens barrel may allow
for simple assembly and cost reduction. Additionally, it is
possible to guide the electric contact out of the lens barrel to
the control integrated circuit by providing slots into the outer
lens barrel.
[0223] Referring now to FIGS. 18 and 19, one example of attachment
of a membrane 1801 to a bobbin 1804 is described. In this example,
the bobbin is the structure around which the coil is wound. A coil
1802 when energized moves thereby moving the bobbin 1804 due to the
interaction of the coil current with a magnetic field created by
the magnet 1806 as directed by a flux guiding path. The membrane
1801 and a cap 1810 are position at an angle indicated by
identifier 1808.
[0224] By indenting, inserting, or otherwise providing the lens
film capture system into the bobbin or molded magnet, a low profile
assembly is provided that may not retain air bubbles in the filling
stage of assembly. Further, the thin ring could be welded in place
for a secure connection. In some examples, there is an
approximately 90 degree meeting of the membrane and the cap on the
liquid side of the lens. However, in the example shown in FIG. 18,
the angle 1808 is closer to approximately 180 degrees. Because
there may be a 0.05 mm radius (as the membrane is positioned
between the cap 1810 and the bobbin 1804), there will still be a
mild indentation (or some small angle between the cap and the
membrane) but the angle will be much smaller than in other
examples.
[0225] A cap 1810 captures the membrane between the cap 1810 and
the bobbin 1804. Curves 1812 of the bobbin 1804 help avoid air
bubble creation or formation in the reservoir. Although applicable
to many types of lens assemblies, this example is particularly
useful in lens assemblies that utilize both the pushing and the
pulling the membrane. The channel indicates a path that creates a
path around the membrane. A hole indicates a pierce and is shown in
FIG. 20B.
[0226] Referring now to FIGS. 20a, 20b, and 21 another example of a
lens assembly is described. A membrane 2002 moves between position
2004 and 2006 and a reservoir 2008 is formed between plate 2010 and
the membrane 2002. A coil 2012 is energized and the electromagnetic
force created pushes the coil 2012 against the membrane 2002. As
especially shown in FIG. 20b, fluid is exchanged via a channel
(e.g., hole) 2014 in the membrane 2002 from a first portion 2016 of
the reservoir to a second portion 2018 of the reservoir as movement
occurs.
[0227] In the example of FIG. 20a and FIG. 20b, the reservoir is
split between different portions. To connect the portions, the
channel 2014 is disposed in the membrane that affects movement of
fluid around the membrane and between different portions of the
reservoir. The channel 2014 could be positioned in the membrane at
any vertical location. In alternative examples, independent
membranes could be used instead of providing a channel. When using
independent membranes, the reservoir location may be completely
independent of the lens location. Because the fluid is being
squeezed, for example, the reservoir can be in any location and
squeezed in any orientation.
[0228] In the example of FIG. 21, as compared to the example of
FIGS. 20a and 20b, the reservoir is lowered. The motor structure is
placed so that the coil 2012 is just under the tangent 2100 of the
initial curve of the membrane. For example, the motor may be moved
a half a millimeter distance compared to the previous examples.
Consequently, a structure is provided that may be less than 10 mm
in height. In this example, the bobbin shape is optimized to
achieve a large lens deformation with small travel. Optimization of
the bobbin structure is further discussed elsewhere in this
specification.
[0229] Referring now to FIGS. 22A, 22B, 23A, 23B, and 23C, examples
of lens assemblies are described where the voice coil motor is
replaced by a piezo actuator. Instead of using a voice coil motor,
these examples deform the lens using a traveling piezo actuator
also called a piezo motor. By using the stick-slip effect, the
small piezo movement can be translated into a large travel
distance.
[0230] The piezo actuator 2202 includes a slider 2204 with piezos
2206. A lens defining sleeve 2208 fits into the slider 2204 and
attaches to a membrane 2210 that covers a reservoir 2212. The
reservoir 2212 is formed between the membrane 2210 and a glass
cover 2211. A housing cover 2214 fits over the entire assembly.
Actuator of the piezo elements 2206 moves the slider 2204 up and
down impacting the membrane 2210 and changes the shape of the
membrane 2210 via the impact. A cover (e.g., glass) is disposed at
the bottom of the assembly.
[0231] As shown especially in FIGS. 23A-C, piezo elements are fixed
to the slider 2204. Alternatively, a single piezo ring can be used.
The slider 2204 travels up and down displacing liquid in the
reservoir 2212 and thereby changes the shape of the lens.
[0232] These examples illustrate moving the slider 2204 along a
vertical path utilizing a piezo actuator elements 2206. As shown,
the piezo actuator elements 2206 are disposed in a ring shape, with
individual strips integrated into the housing or on a moving
component. An advantage of utilizing a piezo-actuated force is that
a relatively large force may be provided by the piezo actuator
elements 2206. In addition, these piezo actuators may only need
power when moving the slider 2204 up and down. Once a specific
focal length is reached, the slider 2204 and the piezo elements
2206 remain fixed in place without using any additional power.
[0233] Referring now to FIGS. 24-30, another example of a lens
assembly 2400 is described. A double coil 2402 presses a bobbin
2404 when excited. The bobbin 2404 is cylindrically shaped and this
shape reduces friction. Flexible contacts 2406 excite the coil.
Magnets 2408 are positioned around the coils 2402. Referring now to
FIG. 30, the bobbin 2402 defines the shape of the membrane 2410. A
lens shaper sleeve 2412 attaches to the membrane 2410. A bottom
plate of cover 2416 seals a reservoir 2414 formed between the
membrane 2410 and the plate 2416. These examples provide a compact
assembly since the axial movement of the lens defining structure
enables not only a displacement of the liquid under the bobbin but
also changes the distance between the lens defining structure and
the bottom plate of cover 2416. This results in an increased
optical effect. In another example, the magnets may be polarized at
an angle (and in radial or non-radial directions as desired).
[0234] Referring now again to FIGS. 25 and 26, an embodiment
similar to FIG. 24 is shown. Here, the upper coil is wound
clockwise and the lower coil is wound counter clockwise. A wire
jump 2413 is provided from upper coil to lower coil. An arched
surface 2415 provides less friction and contact between the bobbin
and the lens shaper (e.g., metal cylinder). Alternatively, ribs may
be placed on the axis of movement. The membrane helps to keep the
relative position of the bobbin perpendicular to the lens shaper
due to the constant pressure in the reservoir. To achieve current
flow in two directions, the wire turns around at a wire jump
point.
[0235] Referring now especially to FIGS. 27, 28 and 29, flux
pattern adjustment based upon the design of the lens assembly is
described. FIG. 27 shows an example flux pattern where no
cylindrical steel cylinder (e.g., cylinder 612 in FIG. 6 that is
shown as a pole in the cross-section) is used as a flux guiding
structure. In the example of FIG. 6, two bobbins move in different
directions. In both FIG. 6 and the present examples of FIGS. 25-29,
radially inward and outward flux is utilized. However, in the
examples of FIGS. 25-29 the bobbin moves in one same direction and
the coil winding changes direction so that the force acts in only
one direction.
[0236] FIG. 28 shows an example where a steel cylinder is used in
the flux guiding structure. FIG. 29 shows an example of the flux
pattern where the magnets are polarized at an angle, which changes
the magnetization direction. In all of these examples, the coil is
wound onto the bobbin. In the example of FIG. 29, the coil has 250
windings, is energized to 100 milli-amperes, and ceramic magnets
are used.
[0237] Referring now to FIG. 31, another example of a lens assembly
is described. A lens defining point 3102 occurs where the membrane
moves from a fully deformed position 3104 to a least deformed
position 3105. The structure 3107 is beveled and presses against
the membrane (the structure is shown raised in FIG. 31 for purposes
of clarity; it is pressed against the membrane). Beveling may
result in various advantages in the present approaches. For
instance, if the contact point between the membrane and the
assembly is shaped whereby it has one or more bevels, it may
provide a more measureable part. Multiple bevels may also reduce
the error associated with the radius 3113 of the lens defining
point 3102. The bevels can also have different shapes such as
circles, ovals or squares.
[0238] As shown in FIG. 31, a first bevel 3106, matched to the
membrane at a low position and high side, just above the position
of the lens at full height is provided. A second bevel 1309 and
third bevel 1311 are also present. The lens may contact some or all
of the second bevel 1309 and the third bevel 1311 but not the first
bevel 1306 as it is deformed. However, the lens defining point 3102
remains constant.
[0239] The lens defining point may actually be a radius (i.e., a
length). Whether the lens defining point 3102 is a single point or
an arc (length) this point can move or remain at a fixed position
depending on the shape of the lens shaper. Examples with single
bevels may be manufactured in metal while examples using multiple
bevels may be manufactured in plastic.
[0240] Referring now to FIG. 32, another example of a lens assembly
3200 is described. The assembly 3200 includes a lens shaper (e.g.,
a plastic component) 3202, a membrane 3204, a coil 3206, a metal
pusher 3208, a housing (e.g., a plastic housing) 3210, a metal
housing 3212, and a cover (e.g., a glass cover) 3214. The cover
3214 and membrane 3204 define a reservoir 3216. In this example,
magnets are not used.
[0241] The metal pusher 3208 and metal housing 3212 are constructed
of magnetically permeable or soft magnetic materials and magnetized
in a polarization such that when current flows through the coil
3206, the metal pusher 3208 moves upward or downward. A rectified
response is achieved where the movement of the pusher is
proportional to the amplitude of the current but independent of the
direction of the current. For example, at 0 amps, the device is in
a rest position. At +0.1 amps and -0.1 amps it moves to the same
closed position. The metal pusher 3208 is attached to the membrane
3204 by an adhesive, fastener, or some other arrangement. The
properties of the remaining components have been discussed
elsewhere herein and will not be discussed further here.
[0242] In operation, the coil 3206 is fixed and when actuated the
metal pusher 3208 is drawn downward. Consequently, the filler
material (e.g., optical fluid) in the reservoir 3216 is displaced,
the membrane 3204 changes shape, and the optical properties of the
lens (membrane 3204, filler material, plate 3212) are adjusted.
[0243] More specifically, when no current flows through the coil
3206, no magnetic field exists and no magnetic field flows through
the metal housing 3212 (constructed of magnetically permeable or
soft magnetic materials). When a current flows through the coil
3206, a closed magnetic flux builds up in the metal parts and this
flux flows through the metal housing 3212 and the metal pusher
3208. The resulting attraction force between the metal pusher 3208
and the metal housing 3212 causes a deformation of the membrane
3204 in the outer ring, resulting in a change of the membrane 3204
in the central, optically active part.
[0244] One advantage of the example described with respect to FIG.
32 is that no permanent magnet snap-in can occur since no permanent
magnets are used. Generally speaking, when the magnets are
positioned too close together, the attraction force between the
magnet and metal is larger than the retention force of the membrane
and the elastic membrane that prevent the magnet and metal from
coming together. Once this occurs, "snap-in" happens, and the
magnet and metal can generally do no more (by themselves) to
separate themselves when the current is removed, meaning that the
device is locked in a fixed position. The configuration of FIG. 32
prevents snap-in from occurring and, if it does occur, allows
snap-in to be easily reversed.
[0245] As shown, no permanent magnets are required making this
approach inexpensive to produce. The coil 3206 is fixed in the
housing and does not move. This makes it shock resistant and easy
to make electrical connections with internal and external
components or devices. Additionally, the lens shaper 3202 is fixed,
providing a high optical quality.
[0246] Referring now to FIG. 33, another example of a lens assembly
3300 is described. The assembly 3300 includes a lens shaper (e.g.,
a plastic component that is not magnetized) 3302, a membrane 3304,
a coil 3306, a metal pusher 3308, a magnet 3310, a metal housing
3312, and a cover (e.g., a glass cover) 3314. The cover 3314 and
membrane 3304 define a reservoir 3316. An elastic rubber seal 3318
is positioned between the metal pusher 3308 and the coil 3306. The
seal 3318 is used as a sealing element as well as for preventing
"snap-in."
[0247] In this example, a permanent magnet 3310 is used that
creates a constant flux in the metal housing 3312 and the metal
pusher 3308. This causes a permanent attraction of the metal pusher
3308 and the metal housing 3312.
[0248] The metal pusher 3308 is magnetized in a polarization
pattern such that when current flows through the coil 3306 (and
depending upon the direction of the current) and due to the
magnetic field created by the magnet 3310, the metal pusher 3308
moves upward or downward. The metal pusher 3308 is attached to the
membrane 3304 by an adhesive, fastener, or some other arrangement.
The properties of the remaining components have been discussed
elsewhere herein and will not be discussed further here.
[0249] In operation, the coil 3306 is fixed and when actuated the
metal pusher 3308 is moved. Consequently, the filler material
(e.g., optical fluid) in the reservoir 3316 is displaced, the
membrane 3304 changes shape, and the optical properties of the lens
(membrane 3304, reservoir 3316, plate 3312) are adjusted.
[0250] More specifically, the initial distance between the metal
housing 3312 and the metal pusher 3308 is defined by the elastic
rubber seal 3318 that works against the attraction forces of the
metal pusher 3308 and the magnet 3310. When a current flows through
the coil 3306, a controllable field is superimposed onto the DC
field. Depending on the current direction, the attraction between
the metal pusher 3308 and the magnet 3310 increases or decreases.
To avoid snap in, the elastic rubber seal 3318 is adjusted such
that the force required to compress the rubber increases more than
the attraction force between the metal pusher 3308 and the magnet
3310, when the distance between the metal pusher 3308 and the
magnet 3310 decrease.
[0251] As shown, no moving coil and no problem with lead out wires
exists. The lens can be tuned in both directions, meaning that the
force on the metal pusher 3308 can be increased or decreased with a
control current. The rubber used in the elastic rubber seal 3318 is
chosen to be hard enough to prevent snap in from occurring. Snap in
can also be prevented by putting non-magnetic elements in the metal
at distances that prevent snap in.
[0252] Referring now to FIG. 34, another example of a lens assembly
3400 is described. The assembly 3400 includes a membrane 3404, a
coil 3406, a metal pusher 3408, a magnet 3410, a metal housing
3412, and a cover (e.g., a glass cover) 3414. The cover 3414 and
membrane 3404 define a reservoir 3416. An elastic rubber seal 3418
is positioned between the metal pusher 3308 and the coil 3406. In
this example, the metal pusher 3408 defines the shape of the
membrane 3404. Compared to the examples of FIGS. 32 and 33, no lens
shaper is used, providing a smaller form factor. The elastic rubber
seal 3418 can be constructed such that the metal pusher 3408
remains well centered and snap in is prevented. In this example,
the position and shape of the lens changes as current is
applied.
[0253] The metal pusher 3408 is magnetized in a polarization such
that when current flows through the coil 3406 (and depending upon
the direction of the current) and due to the magnetic field created
by the magnet 3410, the metal pusher moves upward or downward. The
metal pusher 3408 is attached to the membrane 3404 by an adhesive,
fastener, or some other arrangement.
[0254] In operation, the coil 3406 is fixed and when actuated the
metal pusher 3408 is moved. Consequently, the filler material
(e.g., optical fluid) in the reservoir 3416 is displaced, the
membrane 3404 changes shape, and the optical properties of the lens
(membrane 3404, reservoir 3416, plate 3412) are adjusted.
[0255] Referring now to FIG. 35, another example of a lens assembly
3500 is described. The assembly 3500 includes a lens shaper (e.g.,
a metal component) 3502, a membrane 3504, a coil 3506, a metal
housing 3512, and a cover (e.g., a glass cover) 3514. The cover
3514 and membrane 3504 define a reservoir 3516. In this example,
magnets and a metal pusher are not used. An elastic seal 3518 is
positioned between the metal lens shaper 3502 and the coil 3506.
The metal lens shaper 3502 is attached to and defines the membrane
3504. Compared to the example of FIG. 32, no lens shaper is used,
providing a smaller form factor. Additionally, the elastic rubber
seal 3518 can be constructed such that the metal pusher 3508
remains well centered and snap in is prevented. In this example,
the position and shape of the lens changes as current is
applied.
[0256] The metal lens shaper 3502 is magnetized in a polarization
pattern such that when current flows through the coil 3506, the
metal lens shaper 3502 moves. The metal lens shaper 3502 is
attached to the membrane 3504 by an adhesive, fastener, or some
other arrangement. The properties of the remaining components have
been discussed elsewhere herein and will not be discussed further
here.
[0257] In operation, the coil 3506 is fixed and when actuated the
metal lens shaper 3502 is drawn downward. Consequently, the filler
material (e.g., optical fluid) in the reservoir 3516 is displaced,
the membrane 3504 changes shape, and the optical properties of the
lens (membrane 3504, reservoir 3516, plate 3512) are adjusted.
[0258] Referring now to FIG. 36, another example of a lens assembly
3600 is described. The assembly 3600 includes a lens shaper (e.g.,
a metal component) 3602, a membrane 3604, a coil 3606, a metal
housing 3612, and a cover (e.g., a glass cover) 3614. The cover
3614 and membrane 3604 define a reservoir 3616. In this example,
magnets and a metal pusher are not used and the coil 3606 is on the
same side of the membrane 3604 as the metal lens shaper 3602. An
elastic seal 3618 is positioned between the metal lens shaper 3602
and the coil 3606. The lens shaper 3602 is attached to and defines
the membrane 3604. To minimize height, the metal lens shaper 3602
is disposed on the side of the flexible membrane 3604. The membrane
3604 can be attached to the metal housing 3612 for easy sealing of
the liquid in the lens, or the elastic rubber seal 3618 can be used
as sealing material. In this example, the position and shape of the
lens changes as current is applied.
[0259] The metal lens shaper 3602 is magnetized in a polarization
such that when current flows through the coil 3606, the metal lens
shaper 3602 moves. Amplitude of the current determines movement of
the lens shaper 3602. The metal lens shaper 3602 and the coil 3606
are attached to the membrane 3604 by an adhesive, fastener, or some
other arrangement. The properties of the remaining components have
been discussed elsewhere herein and will not be discussed further
here.
[0260] In operation, the coil 3606 is not-fixed as in the examples
of FIGS. 32-35 but moves with the lens shaper 3602. When the coil
3603 is actuated, the metal lens shaper 3602 is drawn downward.
Consequently, the filler material (e.g., optical fluid) in the
reservoir 3616 is displaced, the membrane 3604 changes shape, and
the optical properties of the lens (membrane 3604, reservoir 3616,
plate 3612) are adjusted.
[0261] As mentioned, the present approaches provide various
advantages. Further, the wear provided by any of the approaches
described herein is superior as compared to that of previous
systems. Since many lens assemblies are often required to provide
100,000 cycles of operation to meet industrial or government
requirements, a plastic construction for many of the assembly
components would likely ensure the assembly components
so-constructed would not fail due to the durability of plastic.
However, other materials may also be used.
[0262] In some push-only lenses as described herein, the coil would
not need to be in contact continually with the lens. The voice coil
could be wound on a bobbin or encapsulated so that it could float
and occasionally rub in the motor gap. Tolerancing can be
configured to enable the bobbin/coating to rub on the motor and not
the coils.
[0263] The closeness of coil to motor may help to minimize shock
problems created when the assembly is bumped, moved, or jarred. An
advantage of these approaches is that proximity of the coil to the
motor wall may allow for assembly to function without disposable
fixtures.
[0264] Using the lens defining structure as a flux guiding
structure allows maximizing the amount of metal and magnet that can
be used and thus maximizing the force generated by the moving coil
and, thus, minimizing the power consumption. Further, using
magnetic members as one part of the housing of the lens assembly
allows an easy assembly without the requirement for glues, making
an assembly much easier and more cost efficient.
[0265] A moving coil as used in the approaches described herein
prevents sticking of magnets to metallic structures. If a moving
permanent magnet were connected to the deformable membrane and a
strong mechanic shock happens, the magnet could permanently stick
to the metal structure (snap in), resulting in a failure of the
lens. This problem is avoided by the approaches described herein
with the use of moving coils.
[0266] For a zoom module two tunable lenses are employed and allow
for the independent control of both lenses. This is not the case
when multiple, moving magnets are used instead of moving coils.
[0267] Further, the membrane deformation can be easily controlled
by varying the current flowing through the coil since the lens
membrane acts as a spring. In addition and as mentioned, the
manufacturing process is very simple, especially in the case where
a deformation of the lens from a flat shape to a balloon shape is
assumed.
[0268] Referring now collectively to FIGS. 37A-37T, another example
of a lens assembly 3700 is described. The lens assembly 3700
includes a top membrane 3702, a bottom membrane 3703, a core
subassembly 3704, a housing base subassembly 3706, a final cover
subassembly 3708, a cushion 3710 (to provide cushioning of the
elements in the assembly 3700 and which can be constructed of any
suitable flexible material such as silicon gel), a top motor
subassembly 3712, and a bottom motor subassembly 3714. The assembly
3700 is configured to achieve one example of an optimal tolerance
structure. Some or all of the optical elements in the assembly 3700
are referenced or indexed through a minimum number of additional or
intervening elements.
[0269] As shown in FIG. 37K, FIG. 37L, and FIG. 37T, the top and
bottom membranes 3702 and 3703 are similar to the other membranes
described herein. In many of these examples, the membranes 3702 and
3703 are at least partially permeable to air. When fully deformed,
the membrane 3702 has been moved in an upward direction and when
fully deformed, the membrane 3703 has been moved in a downward
direction. Other characteristics of the membranes have been
discussed previously herein and will not be discussed further
here.
[0270] As shown especially in FIG. 37B and FIG. 37J, the core
subassembly 3704 includes a top lens cover 3720 (e.g., constructed
from glass or some other transparent material), a top lens aperture
portion 3722 (including an aperture or opening 3723), a central
lens piece 3724, a bottom lens aperture portion 3726 (including an
aperture or opening 3727), and a bottom glass cover 3728. As shown
especially in FIG. 37C, the top membrane 3702 fits over the core
subassembly 3704 and may be attached by an adhesive (e.g., glue) or
some fastener arrangement.
[0271] As shown in FIG. 37S, the central lens piece 3724 includes a
corrective lens 3780 (e.g., with a diameter of approximately 3 mm
in one example), an aperture retaining feature 3782 (for retaining
and holding one of the aperture portions), a retaining feature 3783
(for retaining a cover), a vent 3784 (for releasing air from the
inner portion of the central lens piece 3724, automation handling
points 3785 (for indexing/alignment of the assembly for, example,
attachment to other parts), a reservoir 3785 (with a cover on the
bottom of reservoir), and a membrane attachment surface 3786. The
aperture portions and covers are applied to the central lens piece
3724 to form the core subassembly 3704. It will be under stood that
FIG. 37S shows only one side of the central lens piece 3724 and
that the same features are also present on the bottom portion of
the central lens piece 3724 (for the bottom fluid tunable
lens).
[0272] The center lens piece 3724 may be formed as part of the
outer housing which allows for lower part count, low cost, and
higher tolerances. As mentioned, this structure contains two
reservoirs for each of the two fluid tunable lenses.
[0273] Also as mentioned, indexing features can be used (e.g., four
holes with two on each side to allow for ease of assembly). Vent
holes are also provided to allow air to escape during vacuum
assembly process and to prevent trapped humid air from condensing
when temperatures are colder. The bottom surface of the central
lens piece attaches to the bottom lens shaper 3762 to define
optical tolerances for the bottom membrane 3703.
[0274] The top lens aperture portion 3722 and the bottom lens
aperture portion 3726 are constructed from a material such as
Polyethylene terephthalate (PET) and have apertures 3723 and 3727
extending through respectively. The material is colored black in
many of these approaches.
[0275] As shown in FIG. 37D and FIG. 37N, the bottom motor
subassembly 3714 includes a coil 3730, a bobbin 3731, magnets 3732,
and a flux guiding structure 3734. As shown in FIG. 37E and FIG.
37M, the top motor subassembly includes a coil 3740, a bobbin 3741,
magnets 3742, and a flux guiding structure 3744. To minimize coil
travel, the bobbins 3731 and 3741 surround the optical parts of the
assembly 3700.
[0276] As shown, the motors may include an L-shaped (in the cross
section) octagonal flux guiding structures 3734 and 3744. This
configuration creates a magnetic structure for the assembly that is
both compact and provides for a higher operating point of the
magnet to allow for usage of higher energy product magnets even at
high temperatures.
[0277] As shown in FIG. 37F and FIG. 371, the final cover
subassembly 3708 includes a protective cover 3750 and a lens shaper
3752. As shown in FIGS. 37G and 37H, the housing base subassembly
3706 includes a meniscus lens 3760 and a bottom lens shaper
3762.
[0278] The top lens shaper 3752 includes various features. For
example, force alignment ribs 3753 force the top motor structure
into place and align the top plate to the rest of the structure.
The ribs also provide a force to push the motor structure into the
gel cushion. This feature minimizes the stress of the top cover and
helps to maintain good tolerances of lens shaper. The lens forming
feature also provides barometric relief using vents 3754. Notches
3755 provide coil alignment feature with other portions of the
assembly. The inner diameter of the bobbin aligns with an outer
diameter 3756 of the lens shaper 3752. The lens shaper 3752
includes a cover glass alignment feature (e.g., in the form of a
ring). An undercut is also provided to support gluing of the lens
shaper 3752 to the membrane. These features may be included in the
bottom lens shaper 3762 as well.
[0279] In many of these examples, the configuration (e.g., shape
and dimensions) of the bobbin structure is optimized. In this
respect and as shown in FIG. 37O, the bobbin 3741 is somewhat
shaped (in the cross section) like a "T." The shape of the bobbin
is optimized according to various parameters. First, the force
displacement of the coil/bobbin is required to be great enough to
move the bobbin 3741 with the coil 3740 and displace enough fluid
for full deformation of the lens. In one example, the coil 3740 is
arranged/placed in a high magnetic field area as the membrane 3702
is displaced. Another parameter that may be optimized is the
location where the inner diameter of the bobbin 3741 meets the
outer diameter of the lens shaper 3752.
[0280] If the dimensions of the bobbin 3741 are too small, for
example, if the vertical portion of the "T" is too small,
inadequate force is provided to move the bobbin 3741 by the coil
3740. If the horizontal portion of the "T" is too small, the
membrane may become overstretched because too much bobbin travel is
required to displace enough liquid. In another example, if the
vertical dimensions (i.e., the vertical portion of the "T") of the
bobbin are too long, too high of a fluid displacement occurs in the
x-direction of the reservoir. On the other hand if the horizontal
direction (i.e., the horizontal portion of the "T") of the bobbin
is too large, too much force is required to displace the liquid. It
is desirable to provide medium displacement conditions (somewhere
midway between low displacement and high displacement) by altering
the horizontal and vertical dimensions of the bobbin
accordingly.
[0281] Referring now to FIG. 37P and FIG. 37Q, an example of an
optimized T-shape is shown for the bobbin 3741 as it holds the coil
3740. It will be appreciated that as used herein "T-shaped" may
refer to a structure that is somewhat T-shaped (even in the shape
of an L) rather than exactly T-shaped). In this example, the shape
of the bobbin is optimized such that in the deformed state, an
S-like curve of the membrane 3702 is formed as the membrane 3702 is
moved from a non-deformed condition (FIG. 37P) to a fully deformed
condition (FIG. 37Q). As the membrane 3702 is moved, it is altered
into the "S" shape of FIG. 37Q, which in some examples, has been
found to be an optimal shape.
[0282] The system of FIG. 37 operates in a similar way to some of
the other examples described herein. That is, the coils associated
with each lens are excited by current. This current interacts with
a magnetic flux generated by a permanent magnet guided by a flux
guiding structure associated with each fluid tunable lens. The
interaction between the current and the magnetic flux creates an
electromotive force that moves the corresponding coil. The movement
of the coils act to push their associated membranes and thereby
moves the filler material (e.g., fluid) within the reservoirs
creating a pressure and thereby deforming the shape of the membrane
and overall lens. Consequently, the optical properties of the lens
are altered as required.
[0283] The square (or at least rectangular) cross-sectional shape
of the bobbin 3741 also provides for preferred force versus
displacement characteristics. The coil placement within the bobbin
allows for preferred force displacement in a push only structure.
The coil placement is arranged so that the coil hits the maximum
magnetic flux at point of maximum displacement. The ribs on top of
the coil provide routing features of wires 3749 (see FIG. 37R). The
bobbin 3741 is also configured so that wires from the coil can not
be crimped and damaged as the coil and bobbin move.
[0284] The shape of the bobbin and the size of the horizontal
portion of the "T" gives the distance between the bobbin and fluid
structure so that the membrane achieves an S-shaped displacement
between the bobbin and coil. A membrane that becomes bubble-shaped
in a fully deformed state is undesirable as then the membrane may
rub against/impact other structures. This approach provides a
compact structure and the force displacement curve is changed by
changing the surface area of the portion bobbin that makes contact
with the membrane/fluid reservoir. Optimal configuration of the
surface area of the bobbin with respect to the surface area of the
fluid lens creates leverage so different displacements are obtained
from the lens. When the bobbin is positioned radially outward from
the centrally located optical structure, more surface area on the
bobbin is created and an effective transformation ratio is
achieved.
[0285] All lenses in the lens stack are indexed/can be easily
referenced and their position determined in this example. This
allows for extremely low tolerances on the parts used. In this
regard, the bottom lens shaper 3762 extends further up the assembly
than the top lens shaper extends downward. This part contains the
lens alignment, meniscus lens, image sensor and reference surfaces
to all lenses and lens defining parts. The welding features (the
poles shown on the top of the assembly of FIG. 37A) allow for heat
melt fixturing as well as for alignment and easy assembly. The wire
slot is carefully shaped so that wire can not be broken and can be
brought to a location that is solderable.
[0286] Various approaches can be used to apply anti-reflective
coatings to the existing interfaces (e.g., where air interfaces
with a membrane) in the assembly 3700. In one example, a master
sheet can be used to replicate the nanostructure and transfer this
structure onto the membrane. An uncured polymer is coated onto the
nanostructured master sheet. The master sheet is placed onto the
stretched membrane. The polymer is cured (e.g., using UV or a heat
cure). The master sheet is peeled off of the prestretched membrane,
which has the nanostructured polymer layer attached. Nanoparticles
are applied onto the membrane by inkjet printing or spray coating.
Nanostructures are hot embossed or plasma etched onto the membrane,
which may be prestretched.
[0287] Various approaches can be used to apply the top membrane to
the core/aperture subassembly. The core with apertures subassembly
is inserted into vacuum chamber to avoid air bubbles trapped in the
fluid. Air bubbles can degrade the optical quality. Glue is applied
to top attachment surface. Fluid is dispensed into the top liquid
reservoir. The membrane is placed on top surface and the glue is
cured. The remaining air diffuses through the semi-permeable
membrane.
[0288] The core assembly can be assembled using the following
procedure. The core assembly with apertures subassembly is inserted
into a vacuum chamber (e.g., 10 mbar to remove 99% of air or 100
mbar to remove 90% of the air). Glue is applied to the top
attachment surface. Fluid is dispensed in the top liquid container
(reservoir). A membrane is placed on the top surface and the glue
is cured. UV cement may also be used for time savings and to
provide stability.
[0289] The central lens portion is then reversed (i.e., flipped
over). Glue is applied to the bottom attachment surface. Fluid is
dispensed into the bottom liquid container (reservoir). A membrane
is placed on the bottom surface. The glue is cured. The core is
removed from vacuum chamber and singulation of the part may be
performed (e.g., a hot knife can be used).
[0290] Other portions of the assembly 3700 of FIG. 37 may be
assembled in a variety of different ways. The core with apertures
assembly may be assembled by applying the top lens aperture to the
top side of the central lens piece (CLP) The top lens cover is
added to top side of CLP. Glue is applied into groove between the
aperture and CLP. A fixture is used to secure glass during
operation. The CLP is flipped (i.e., reversed) and the bottom lens
aperture is applied to the bottom side of the CLP. The bottom lens
cover is attached to the bottom side of the CLP. Glue is applied
into groove between the aperture and the CLP and the glue is cured
under ultraviolet radiation. A thicker glue may be used to avoid
flow problems.
[0291] Pre-stretching of the membranes may be used to provide
better optical quality. Prestretching may prevent wrinkling of the
lens, reduce gravitational effects on the lens shape, and allow for
faster responses of the lens of electrical application to the
coil.
[0292] The housing base can be assembled by inserting the meniscus
lens into the bottom lens shaper. Glue is applied into groove
between the meniscus lens and the bottom lens shaper and the glue
is cured.
[0293] The bottom motor subassembly can be assembled by inserting
the bottom flux guiding structure in the bottom lens shaper. The
bottom magnets are inserted onto the bottom flux guiding structure.
Glue is applied into gaps between the magnets and cement curing
temperature is lowered. The bottom coil is inserted onto the
magnets by inserting/threading the wires through the bottom lens
shaper and attaching the wires to any relating pins (e.g., on an
external device).
[0294] The top motor subassembly is assembled by inserting the top
magnets into the top flux guiding structure (e.g., into the corners
and, if necessary, cement is applied). The top coil is inserted
onto the magnets by inserting/threading the wires through the top
flux guiding structure.
[0295] The final cover subassembly may be assembled by placing the
top protection plate onto the top lens shaper. Glue is applied into
gap between top protection plate and the top lens shaper and the
glue is cured.
[0296] The core of the assembly is assembled by inserting the core
subassembly into the bottom motor subassembly. The cushion is
applied on core subassembly. The cushion can be made from silicon
rubber of an appropriate hardness and flexibility. The cushion can
be delivered in a roll for use in the assembly process. The flaps
of the cushion are applied to cover the central lens. The top motor
is inserted and the final cover is placed onto the alignment pins.
A hot melt is used with the alignment pins with the final cover.
The wires from the coil are soldered to the appropriate pins (e.g.,
of an external device).
[0297] It will be appreciated that the manufacturing/assembly
approaches described above are examples only and may be
changed/modified as needed to suit the particular requirements of a
user or specific design. For example, the materials, processes
used, tools used, dimensions, actions performed, and the order of
the steps performed can be altered/changed with these approaches.
In addition, other examples of approaches for
assembling/manufacturing all or some of the above-mentioned
elements are possible.
[0298] Referring now to FIGS. 38A-F, one example of a bobbin
structure that has its dimensions and configuration optimized
according to the principles described herein is described. Now
referring specifically to FIG. 38A, the inner diameter of a bobbin
3802 is matched to the outer diameter of the lens defining
structure 3804. It has been found that if the bobbin 3802 has a 1%
tolerance and lens defining structure 3804 has a tolerance of 1%,
the difference between the two elements is barely larger than 2% of
the radius of the assembly. A coil 3806 is positioned inward of the
magnet 3808.
[0299] For the top motor, the bobbin 3802 is optimally placed when
the coil 3806 just reaches the end of the magnet 3808 indicated by
position 3803. The top dimension of the coil 3806 is as large as
the assembly will allow. In some examples, this extends to the top
of the magnet 3808 while in other examples it does not.
[0300] A limited space exists between the lens defining structure
3804 and the outer diameter of the lens assembly. Both the coil
3806 and the magnet 3808 fit into this space. In some examples, the
optimum amount of coil 3806 from a force perspective is
approximately 0.5 mm. Larger coil widths produce the same amount of
force but the operating point of the magnet 3808 will be reduced as
the magnet gets smaller. Winding widths of less than approximately
0.5 mm have been found to produce less force in these
approaches.
[0301] Referring now to FIG. 38B, a membrane 3810 is shown in the
un-deformed position. As shown in FIG. 38C, the membrane 3810 is
shown in the fully deformed condition.
[0302] Referring now to FIG. 38D, if the portion 3805 (the
horizontal portion of the T) is too large, the membrane 3810 will
stretch as a straight line and extra force will be required to
deform the membrane 3810. Referring now to FIG. 38F, if the portion
3805 is too small, the membrane 3810 will tend deform inward and
force will be wasted deforming the reservoir portion of the
membrane 3810. In one example as shown in FIG. 38E of an optimum
configuration for the portion 3805 (and the bobbin 3802),
deformation of the membrane 3810 will tend to assume an S-like
shape.
[0303] Referring now collectively to FIGS. 39A-39E, another example
of a lens assembly 3900 is described. In this example, the bottom
flexible lens points to an object and not the sensor as shown in
the examples of FIG. 37. The lens assembly 3900 includes a top
membrane 3902, a bottom membrane 3903, a first core subassembly
3904, a second core subassembly 3905, a housing base subassembly
3906, a final cover subassembly 3908, a top motor subassembly 3912,
a bottom motor subassembly 3713, a first aperture portion 3922, a
second aperture portion 3923, a top fixed lens 3940 (e.g., a
corrective lens), a bottom fixed lens 3941 (e.g., a meniscus lens),
a first plate 3943, a second plate 3944, a first reservoir 3945,
and a second reservoir 3946. The plate and membrane combinations
define the shape of the respective reservoirs. Consequently, the
assembly 3900 includes two tunable (e.g., fluid tunable) lenses and
two fixed lenses. The assembly 3900 can be operated to provide
zoom, autofocus, or other optical functions.
[0304] In this example, two core subassemblies 3904 and 3905 are
provided and each of these subassemblies serves one liquid
reservoir (chamber) 3945 and 3946. Consequently, production yield
problems are reduced, since the reservoirs (containers) can be
constructed independently. Additionally, no side actions (i.e., the
process in injection molding that requires a part of the tool to
come from/positioned/used the side, that allows for making a
structure that cannot be created by a two dimensional process) are
required to provide the barometric relieve holes in the lenses. The
top lens shaper and bottom fixed lens 3941 (e.g., a meniscus lens)
are both fixed using, for example, heat melt.
[0305] As shown in FIG. 39B, the top motor subassembly 3912
includes a top coil 3930 top magnets 3931, and a top bobbin 3950.
The bottom motor subassembly 3913 includes a bottom coil 3932,
bottom magnets 3933, and a bottom bobbin 3951. A top lens shaper
3934 defines the lens 3902. A bottom lens shaper 3936 defines the
bottom lens 3903. The operation of the assembly 3900 to adjust the
shape of membranes 3902 and 3903 has been described previously and
will not be repeated here.
[0306] As shown in FIG. 39C, coil wires 3938 exit through the
bottom lens shaper 3936. Threading of the wires 3938 is used to
remove the wires 3938 from the assembly 3900 during the
manufacturing process.
[0307] As shown in FIG. 39D, the first aperture portion 3922 is
colored black to provide absorptive properties. A bottom cushion
3917 is used to fix the bottom motor and to compensate tolerances.
Heat welding 3919 may be used similar to the final cover assembly.
As shown in FIG. 39E, vents 3937 may be used to provide barometric
relief for the assembly 3900.
[0308] Referring now to FIGS. 40A-C, another example of a lens
assembly 4000 is described. The lens assembly 4000 includes a top
membrane 4002, a core subassembly 4004, a housing base subassembly
4006, a final cover subassembly 4008, a motor subassembly 4012, a
first aperture portion 4022 (e.g., colored black to provide
absorptive properties), a second aperture portion 4023 (e.g.,
colored black to provide non-reflective properties), a top fixed
lens (e.g., a corrective lens) 4041, a middle fixed lens 4040
(e.g., a corrective lens), a bottom fixed lens 4042 (e.g., a
meniscus lens), a cushion 4010 (to provide cushioning of the
elements in the assembly 4000 and which can be constructed of any
suitable flexible material such as rubber), a top cover 4044 (e.g.,
constructed of glass), a top lens shaper 4045, a plate 4046, and a
reservoir 4047. The plate and membrane combination defines the
shape of the reservoir 4047. The motor subassembly 4012 includes a
bobbin 4050, a coil 4051, and magnets 4052. The operation of the
assembly 4000 in adjusting the shape of membrane 4002 has been
described previously and will not be repeated here. In addition,
the many of the elements present in FIG. 40 have already been
discussed herein (e.g., with respect to the examples of FIGS. 37
and 39) and their composition and functionality will not be
discussed further here.
[0309] The assembly 4000 includes one fluid tunable lens and three
fixed lenses. Barometric relief may be provided via chamfers 4053
in the fixed lenses. In this example, the fixed lenses 4040, 4041,
and 4042 may be press fit into the assembly 4000. In one example,
the tunable lens may be operated as a part of an autofocus
module.
[0310] Referring now to FIGS. 41a and 41b, another example of lens
shaping is described. A first membrane 4102 is attached at an
attachment point (4104 in FIGS. 41a and 4106 in FIG. 41b). A second
attachment point 418 is also shown in FIG. 41A. The assembly also
includes a support 4108 and a lens shaper 4110. FIG. 41a shows the
lens in a convex shape and FIG. 41b shows the lens in a concave
shape. A first theoretical line 4136 and a second theoretical line
4138 are also shown in FIG. 41A. The lines define a connection
angle 4135.
[0311] To achieve a precise lens that can be tuned in a convex and
concave state while keeping a high quality shape, the lens shaper
4110 is formed such that the membrane attach point is defined by a
single lens shaper. To avoid the use of glue, the support 4108 is
placed at a first angle alpha between the support 4108 and the lens
shaper and this angle alpha is larger than the curvature of the
membrane in the concave position (indicated by the angle beta). In
one advantage of these approaches, no gluing is needed as between
the lens shaper and the support and, at the same time, the lens
attachment point is well defined.
[0312] As shown in FIG. 41A, the deformable lens defines at least
by the first membrane 4102 and a filler material. The deformable
lens is in contact with the lens shaper 4110 at a contact region,
and not in contact with the lens shaper at a non-contact region.
The first detachment point 4104 is defined as the interface between
the contact region and the non-contact region. The first detachment
point 4104 defines a diameter of the deformable lens. The shape of
the lens shaper 4110 allows for a location of the first detachment
point 4104 to vary with deformation of the deformable lens, such
that the diameter of the deformable lens varies with the location
of the first detachment point 4104. In some examples, an axial
position of the detachment point 4104 varies with the deformation
of the deformable lens.
[0313] In others of these examples, the optical apparatus further
includes a first support member 4108; a second membrane (or
membrane portion or section) 4132 which is a subset of the first
membrane that is in contact with the lens shaper 4110 at the
contact region; a third membrane (or membrane portion or section)
4140 which is connected with an end of the second membrane 4132 and
the first support member 4108; a second detachment point 4138 which
is located at a connection point between the second membrane 4132
and the third membrane 4140. The first theoretical line 4136 is
tangent to the lens shaper 4140 at the first detachment point 4140
and the second theoretical line 4134 is tangent to the lens shaper
4110 at the second detachment point 4138. The connection angle 4135
is defined as an angle between the first theoretical line 4136 and
the second theoretical line 4134 and is a supplementary angle to an
angle that contains a majority of the lens shaper 4110. A
connection angle positive sense is defined as being in a direction
from the second theoretical line 4134 through the first theoretical
line 4136 and towards the lens shaper 4110 wherein the connection
angle 4135 does not span across the lens shaper 4110. The absolute
value of the connection angle 4135 is between 0 and 180
degrees.
[0314] In some examples, only frictional forces are used to hold
the first membrane 4102 to the lens shaper.
[0315] In still other examples, the apparatus further includes a
second lens shaper, and a third lens shaper. Deformation of the
deformable lens causes the lens shaper to shift from the second
lens shaper to the third lens shaper and changes the diameter of
the deformable lens.
[0316] In still other examples, the optical apparatus further
includes a second lens shaper and a third lens shaper. Deformation
of the deformable lens causes the detachment point to shift from
the second lens shaper to the third lens shaper and changes an
axial position of the deformable lens.
[0317] Referring now to FIGS. 42A-D, it will be appreciated that
the above-described approaches can be used in conjunction with two
variable lens structures 4202 and 4204. As shown in these examples,
the bottom and top lens can expand into either concave or convex
shapes and can be used in the various combinations shown and
according to the various approaches described herein.
[0318] Referring now to FIG. 43, a coil 4302 moves from a first
position 4304 to a second position 4306. If the coil 4302 were to
move below a plane 4308 of a magnet 4310, the flux normal to the
current in the coil that produces the moving force would rapidly
decrease or be eliminated. In the present example, in the most
deformed state the coil 4302 is aligned to the bottom surface of
the magnet 4310. As shown in FIG. 43, a flux plot is shown where
the coil 4302 is in the most deformed position. As shown, the
bottom of the coil 4302 is aligned with the bottom of the magnet
4310.
[0319] The approaches described herein can be used with membranes
that are thicker than used in previous systems. In some examples,
membranes having a thickness of 10-50 um and a stiffness (Young's
modulus) of 0.5 MPa are used. Other examples are possible.
[0320] Relatively thick membranes offer several advantages. For
example, thicker membranes allow easier processing of the membrane
in production and their shape is easier to maintain. Additionally,
the membrane is less prone to gravitational effects (when the lens
is in a vertical position) so that larger lenses are possible that
still provide good optical quality. Also, a thicker membrane is
less likely to rupture when handled or when a shock occurs. The
membrane thickness is easier to control (1 um thickness variation
is only 1% for a 100 um thick membrane, but 10% for a 10 um thick
membrane) and results in an improved optical quality. Additionally,
thicker membranes make it easier to integrate an AR coating into a
thicker membrane.
[0321] Referring now to FIG. 44, one example of an approach for
adjusting the optical characteristics of one or more lenses is
described. At step 4402, conversion of electrical energy to
mechanical energy occurs. The conversion of electrical energy to
mechanical energy may be accomplished by using any
electrical-to-mechanical actuation device such as a piezoelectric
motor, a magnetostrictive motor, a stepper motor, or a voice coil
motor to name a few examples. The piezoelectric motor may be a
quasi-static, ultrasonic, stepping, inertial, standing wave,
travelling wave, bidirectional, or unidirectional piezoelectric
motor to name a few examples. Such motors are of the models
typically manufactured by Williams and Brown, Konico Minolta, New
Focus, Lavrinenko, Bacnsiavichus, Nanomotion, Physik Instrumente,
or New Scale corporations to name a few examples of piezoelectric
motor manufacturers.
[0322] In some of the examples described herein, the motor is
described as being a piezoelectric motor. However, it will be
appreciated that the motor may be any type of suitable
electrical-to-mechanical actuation device such as a electroactive
polymer motor, magnetostrictive motor, a voice coil motor, or a
stepper motor. Other examples of motors or devices are
possible.
[0323] At step 4404, the mechanical force (produced at step 4402)
is converted to a pressure that eventually alters the optical
properties of a lens. The lens may be a three-dimensional space
filled with a filler material and communicating with a reservoir.
The electrical-to-mechanical actuation device (e.g., piezoelectric
motor) creates the mechanical force to directly or indirectly act
on a filler material within the lens and/or the reservoir.
[0324] In one approach, the linkage structure mechanically
interconnects to a surface of a reservoir and the linkage structure
includes drive rods, paddles, pins, adhesives, to name a few
examples. The mechanical force communicated by the linkage
structure creates a pressure over a surface of the reservoir and
the pressure moves the filler material in the reservoir and/or
lens. More specifically and as mentioned, the reservoir
communicates with the lens and the filler material is exchanged
between the reservoir and the lens based upon the direction,
magnitude, or other property of the force acting on the reservoir.
It will be appreciated that in many of the examples described
herein, one or more reservoirs are described as being
interconnected or communicating with a lens and filler material is
exchanged between these two distinct spaces. However, it will be
appreciated that instead of two labeled, separate, and distinct
spaces (i.e., lens and reservoir) a single space (e.g., a single
reservoir) can be used and filler moved within this single
space.
[0325] Additionally, the reservoir can be one or more reservoirs.
Multiple reservoirs, combinations or reservoirs and tubes or
channels may also be used. The reservoir can be directly connected
to the lens (i.e., the optical area where optical properties are
determined) via an open channel or opening or through a network of
one or more fluid chambers. Other configurations are possible.
[0326] At step 4406, pressure to the membrane causes optical
deformation of the lens to occur. The dimensions, curvature, and
shape of membrane at least in part determine the optical properties
of the lens within the lens assembly. The pressure in the filler
(e.g., optical fluid) deforms the membrane and determines the
amount of deformation that occurs. The membrane can be deformed so
as to be concave, convex, or flat in shape. The curvature of the
membrane can be spherical among other shapes. Other examples are
possible.
[0327] Referring now to FIG. 45A, one example of a lens assembly
4500 is described. The lens assembly 4500 includes a top housing
4501 having a top lens shaper 4522, a bottom housing 4502 having a
bottom lens shaper 4523, a top filler 4512, which is enclosed
between a top container 4503 and a top membrane 4505, a bottom
filler 4513, which is enclosed between a bottom container 4504 and
a bottom membrane 4506. It will be appreciated that in the figures
the term "top" will denote the side of the lens assembly through
which light enters the lens assembly, and that "bottom" will denote
the side of the lens assembly through which light exits the lens
assembly to be projected, for example, on a sensor. It will also be
appreciated that although in all the examples the optic axis, being
the line through the nominal center of the optical components, is
illustrated as single straight line, it is possible to introduce a
reflective component, such as a mirror or prism, to alter the
direction of the optic axis before, in between, or after the
optical components in the lens assembly. The membrane 4505 may be
divided by a top lens shaper 4522 into an inner section 4565 and an
outer section 4555. The membrane 4506 may be divided by a bottom
lens shaper 4523 into an inner section 4566 and an outer section
4556. A perimeter of the inner section 4565 extended toward the top
container 4503 divides the filler into a lens (bounded by the inner
section 4565) and a reservoir (exterior to the inner section). A
perimeter of the inner section 4566 extended toward the bottom
container 4504 divides the filler 4513 into a lens (bounded by the
inner section 4566) and a reservoir (exterior to the inner
section). The containers 4503 and 4504 in one example are hard
plastic members (e.g., plates). In another example, the containers
4503 and 4504 are constructed from glass and/or other optical
materials and provide optical correction functions. Other materials
may also be used to construct the containers 4503 and 4504. Light
rays 4550 pass through and their properties are altered by the lens
assembly 4500 and the altered rays are sensed by a sensor 4552,
which may, in one example, be an electronic sensor chip.
[0328] The housings 4501, 4502 support all or some of the other
elements and may be constructed of plastic or any other suitable
material. The top lens shaper 4522 and the bottom lens shaper 4523
define the two-dimensional shape of their respective membranes and
hence the shape of the lens. In particular, the lens shapers
contact the respective membranes 4505 and 4506 and define the
perimeter of, and to a certain extent, the shape of the lenses 4531
and 4535 due to their contact with the membranes 4505 and 4506.
Other factors which can contribute to the shape of the lenses 4505,
4506 are elastic stress in the membrane, and the hydraulic pressure
of the filler in the filler volume. The filler volume is considered
as the total volume of filler in the lens and reservoir, a
preponderance of which may exist between the membrane and the
container. A balance of forces between the filler pressure and
restoring forces in the membrane as constrained by the shaper ring
determines the shape of the lens.
[0329] The membranes 4505 and 4506 bounding the lens are made at
least partially of a flexible material. The inner sections of the
membranes and the outer sections may be made of the same membrane
material. However, in other examples the actuator section of the
membrane and the inner section are constructed of different
membrane materials. The properties of the membranes 4505 and 4506
and/or the filler materials (e.g., an optical fluid) combine to
provide reflective, refractive, diffractive, and absorptive, and/or
color filtering functions. Other functions may also be provided by
the membrane and/or the filler material in the reservoirs. An
optional top plate (not shown) may be used to cover the top of the
assembly 4500.
[0330] The membranes 4505 and 4506 and the containers 4503 and
4504, define a filler volume which consists of the reservoirs 4533
and 4537, as well as lenses 4531 and 4535, respectively. Different
filler materials (e.g., fluid, ionic liquids, gas, gel, or other
materials) can be used to fill the reservoirs 4533, 4537 and lenses
4531, 4535. The refractive indexes of the filler materials 4512 and
4513 used to fill the reservoirs and lenses may also vary. In one
example, a fluid is used as the filler material and the refractive
index of the fluid in the reservoirs and lenses is selected to be
different from the refractive index of the surrounding air.
[0331] By axially moving or interacting with the containers 4503
and 4504 using piezoelectric motors (for clarity, not shown in FIG.
45A), the membranes 4505 and 4506 are deformed (via pressure from
movement of the filler materials 4512 and 4513) resulting in a
changed optical behavior of the lenses in the lens assembly. A top
corrective lens 4520 is positioned at the bottom of the first
container 4503 and a second corrective lens 4529 is positioned at
the top of the second container 4504. The corrective lenses 4520
and 4529 are passive components (e.g., their shape does not change)
and ensure proper focusing of the light 4550 passing through the
lens assembly 4500. For example, if the lens assembly provides zoom
and/or autofocus functions, then the corrective lenses 4520 and
4529 ensure proper focusing of the received light at the sensor
4552.
[0332] Referring now to FIGS. 45B and 45C, one example of a lens
assembly shown in two states of operation is described. The labels
for the elements in these figures correspond to the labels used in
FIG. 45A. As shown in FIG. 45B, the top corrective lens 4520 and
the bottom corrective lens 4529 are separated by a distance d3. As
shown in FIG. 45C, the piezoelectric motor (for clarity not shown
in these figures) has been actuated to move the containers 4503
and/or 4504. Consequently, since the containers 4503 and 4504 move,
the distance between the corrective lenses 4520 and 4522 decreases
as shown in FIG. 45C to a distance d4. Consequently, the approaches
described herein can automatically adjust at least some focusing
properties of the lens 4500.
[0333] Referring now to FIGS. 46A and 46B, a detailed view of a
lens assembly showing the piezoelectric motors that are located in
the corners of the housing is described. A lens assembly 4600
includes a top housing 4601, a top lens shaper 4622, a bottom
housing 4602, a bottom lens shaper 4623, a top filler 4612, which
is enclosed between a top container 4603 and a top membrane 4605, a
bottom filler 4613, which is enclosed between a bottom container
4604 and a bottom membrane 4606. The top membrane 4605 may be
divided by a top lens shaper 4622 into an inner section 4665 and an
outer section 4655. The bottom membrane 4606 may be divided by a
bottom lens shaper 4623 into an inner section 4666 and an outer
section 4656. A perimeter of the inner section 4665 extended toward
the top container 4603 divides the filler into a lens (bounded by
the inner section 4665) and a reservoir (exterior to the inner
section). A perimeter of the inner section 4666 extended toward the
bottom container 4604 divides the filler 4613 into a lens (bounded
by the inner section 4666) and a reservoir (exterior to the inner
section). The containers 4603 and 4604 in one example are hard
plastic members (e.g., plates). In another example, the containers
4603 and 4604 are constructed from glass and/or other optical
materials and provide optical correction functions. Other materials
may also be used to construct the containers 4603 and 4604. As they
move, the containers 4603 and 4604 are guided by ball bearings 4640
and 4641 on one side of the assembly 4600 and on the other side of
the assembly 4600 by a first piezoelectric motor 4642 and a second
piezoelectric motor 4643. The piezoelectric motors 4642 and 4643
may be coupled to linkages 4645 and 4646 and the linkages 4645 and
4646 may, in turn, be coupled to the containers 4603 and 4604. The
ball bearings 4640 and 4641 may couple to linkages 4648 and the
linkages 4647 and 4648 may communicate with the containers 4603 and
4604. In other examples, the linkages are omitted.
[0334] The membranes 4605 and 4606 bounding the lens are made at
least partially of a flexible material. The inner sections of the
membranes and the outer sections may be made of the same membrane
material. However, in other examples the actuator section of the
membrane and the inner section are constructed of different
membrane materials. The properties of the membranes 4605 and 4606
and/or the filler materials (e.g., an optical fluid) combine to
provide reflective, refractive, diffractive, and absorptive, and/or
color filtering functions. Other functions may also be provided by
the membrane and/or the filler material in the reservoirs. An
optional top plate (not shown) may be used to cover the top of the
assembly 4600.
[0335] The membranes 4605 and 4606 and the containers 4603 and
4604, define a filler volume which consists of the reservoirs 4633
and 4637, as well as lenses 4631 and 4635, respectively. Different
filler materials (e.g., fluid, gas, gel, or other materials) can be
used to fill the reservoirs 4633, 4637 and lenses 4631, 4635. The
refractive indexes of the filler materials 4612 and 4613 used to
fill the reservoirs and lenses may also vary. In one example, a
fluid is used as the filler material and the refractive index of
the fluid in the reservoirs and lenses is selected to be different
from the refractive index of the surrounding air.
[0336] By axially moving or interacting with the containers 4603
and 4604 using piezoelectric motors 4642 and 4643, the membranes
4605 and 4606 are deformed (via pressure from movement of the
filler materials 4612 and 4613) resulting in a changed optical
behavior of the lenses in the lens assembly. A top corrective lens
4620 is positioned at the bottom of the first container 4603 and a
second corrective lens 4629 is positioned at the top of the second
container 4604. The corrective lenses 4620 and 4629 are passive
components (e.g., their shape does not change) and ensure proper
focusing of the light passing through the lens assembly 4600. For
example, if the lens assembly provides zoom and/or autofocus
functions, then the corrective lenses 4620 and 4629 ensure proper
focusing of the received light at the sensor (for clarity, not
shown in FIG. 46A or 46B.)
[0337] As shown in FIGS. 46A and 46B, the containers are guided on
one side with ball-bearings 4640 and 4641 and on the other side by
the piezoelectric motors 4642 and 4643. When a voltage is applied
to the piezoelectric motors 4642 and 4643, the piezoelectric
material (within the piezoelectric motors) deforms or vibrates,
resulting in movement of some elements of the motors, and this
movement is communicated to the linkages 4645 and 4646 which are
moved, and this linkage movement moves the containers generally in
a direction indicated by arrows labeled 4624. In this example, the
piezoelectric motors 4642 and 4643 are independently controlled
(i.e., separate control signals are applied to each to
independently control the shaping of each lens).
[0338] The deformation or vibration of the piezoelectric material
within the piezoelectric motors 4642 or 4643 is controlled such
that in one direction, the linkage is sticking on a contact surface
of the container and in the other direction, the linkages and
containers are sliding on or with respect to each other (i.e.,
slipping), thereby enabling container movement in a specific
direction. This "stick-slip" behavior results in an axial movement
of the containers. By changing the shape (or other characteristic)
of the electrical signal, the stick-slip motion can be reversed,
resulting in a reversed direction of the axial movement of the
containers. The various container movements result in various
deformations of the membrane (and lens) and thus result in a change
of the optical properties of lens. In some examples, ball bearings
are used to prevent tilting of the liquid container and to reduce
friction force. Alternatively, the piezoelectric motors may
directly drive or move the containers without an intermediate
linkage. It will also be appreciated that two piezoelectric motors
are provided and this provides for the independent control of each
resulting in the ability to independently shape the top and bottom
lenses (i.e., two degrees of freedom). In another embodiment, a
single motor capable of independent motion along two axes may also
be used.
[0339] The piezoelectric motors 4642 or 4643 can be shear, stack or
rotating piezoelectric motors to name a few examples. For example,
the piezoelectric motor in FIGS. 46A and 46B is a shear piezo block
that is fixed on the housing 4602 of the lens assembly.
Alternatively, the piezoelectric motors 4642 and 4643 may be
connected to a metal, plastic or ceramic pin that rotates due to
deformation of the piezoelectric material located within these
devices (e.g., see the example of FIGS. 50 and 55). This rotation
is translated in an axial movement of the containers, which are
interconnected to the optical membrane. In general, it is
advantageous to position the piezoelectric motors 4642 or 4643 in
or at a non-moving part with respect to the housing 4602, such that
it is easier to connect the piezoelectric motor 4642 or 4643 with
an electrical power supply.
[0340] In an embodiment, to allow for efficient functioning of the
device, an air exchange between the optical opening in the housing
and the section with the motor pushing onto the membrane is
required. This can either be achieved through venting holes 4651 or
small slits in the housing. Venting holes 4651 are placed so that
the air displaced by fluid movement in the lens and the reservoir
can equalize with the outside air. Alternatively, the exchange
could occur between the air over the reservoir and the air over the
lens. If desired, an air spring could be used to slow air movement
and the vents could be removed.
[0341] The assembly 4600 may be combined with other focus tunable
and non-focus tunable lenses, filters and any other combination of
optical systems, including mirrors, gratings, prisms, shutters,
image stabilizers and apertures. The assembly 4600 can be used with
or include other elements as well.
[0342] The amount and direction of piezoelectric motor movement may
be controlled by any number of devices or approaches. For example,
a user may manually press a switch, button, or other control device
to control the voltage. In another examples, the applied voltage
may be controlled by a program or algorithm (e.g., an autofocus or
zoom program or algorithm), which adjusts automatically the voltage
applied to the motors.
[0343] Referring now to FIGS. 47A-D, another example of a lens
assembly 4700 is described. The lens assembly 4700 includes a top
housing 4701, a bottom housing 4702, a top lens shaper 4722, a
bottom lens shaper 4723, a top and a bottom container 4703 and
4704, four piezoelectric motors 4742, 4743, 4744, and 4753, four
electric cushions 4710, 4777, 4778, and 4779, a top ring 4714 and
bottom ring 4715, and a top and bottom membrane 4705 and 4706,
respectively. The top membrane 4705 and top container 4703 form a
top filler volume 4717 and the bottom membrane 4706 and bottom
container 4704 form a bottom filler volume 4718. The filler volumes
4717, 4718 include all of the three dimension space between the
membrane and containers. Each of the filler volumes 4717 and 4718
are filled with a filler material such as a liquid, ionic liquid,
gel, or some other filler material. Vents 4751 allow air to flow in
and out of the non-filled regions in the lens assembly 4700. The
various elements are constructed according to the approaches
described elsewhere herein and this construction will not be
repeated here.
[0344] A central opening 4730 extends in an axial direction (in the
direction of the z-axis) through the assembly 4700. Light rays 4750
project through the central opening 4730 in the lens structure in
the axial direction. Once acted on by the tunable lenses and other
optical components not shown in the drawing of the lens structure,
a sensor 4752 (e.g., a capacitive charged device (CCD)) may receive
and sense the image. The sensor 4752 may communicate with other
processing elements that further process and/or store the obtained
image.
[0345] In this example, the rings 4714 and 4715 are attached to the
membranes 4705 and 4706, respectively. Attachment may be made by
any adhesive or fastener arrangement (e.g., glue). This allows, for
example, an operation that requires pushing and pulling on the
membrane 4705 and 4706, to thereby shift or tune the lens from a
convex shape to a concave shape. To prevent gravitational effects,
both sides of the reservoirs 4712 and 4713 may, in an embodiment,
be filled with a filler material (e.g., liquids) having similar
densities, but with different indices of refraction.
[0346] In the example of FIGS. 47A-47D, the optical membrane 4705
is made of flexible material. The inner section of the membranes
4705 and 4706 and the outer section may be made of one membrane
material. However, in other examples the outer section of the
membrane and the inner section are constructed of different
membrane materials. The membrane or the filler material (e.g., an
optical fluid) can combine to provide various reflective,
refractive, diffractive, and absorptive, or color filtering
properties for the system. Other properties may also be
provided.
[0347] The piezoelectric motors 4742, 4743, 4744, and 4753 are made
of any type of bending, shear, stack or rotating, or multi-modal
piezoelectric actuator. The electrical cushions 4710, 4777, 4778,
and 4779 can be made of conducting and non-conducting polymers
(e.g., foam) and may be used to fill out the structure to prevent
component movement, allow for assembly tolerances, and/or
slippage.
[0348] The rings 4714 and 4715 may be made of material(s)
contemplated by those of skill in the art. In one example, the
rings 4714 and 4715 are constructed from a plastic material. To
improve the stick-slip interaction with the piezoelectric motors
4742, 4743, 4744, and 4753, the rings 4714 and 4715 may be made of
metal or may incorporate a metal pin that is in direct contact with
the piezoelectric motors 4742, 4743, 4744, and 4753. During
stick-slip operation, the piezoelectric motor moves the rings 4714
and 4715 via contact with the rings 4714 and 4715. Eventually,
contact may be lost (e.g., as the piezoelectric motor rotates or a
portion thereof rotates off or away from the ring 4714 or 4715) and
the piezoelectric motor 4742, 4743, 4744, and 4753 and the ring
slide against each other (i.e., slipping occurs). For example, the
piezoelectric motors 4742, 4743, 4744, and 4753 may have or drive a
rotating cylindrical portion that at one time contacts the ring
4714 or 4715 and through friction with the ring sticks or adheres
to (due to friction) the ring. During this time, the ring 4714 or
4715 is moved. At other times, the friction is not strong enough to
engage/move the ring 4714 or 4715 and the ring and cylindrical
element of the piezoelectric motor 4742 or 4743 slide
against/relative to each other. In this way, the rings 4714 or 4715
are moved by the piezoelectric motors 4742, 4743, 4744, and 4753.
It will be appreciated however, that other actuating approaches and
techniques besides the stick-slip approach can be used to move the
rings 4714 or 4715.
[0349] By using stick-slip or other approaches to move mechanical
parts, the piezoelectric motor is moving the lens rings 4714 or
4715 in axial direction either upward or downward generally in
directions indicated by the arrow labeled 4724. The rings 4714 and
4715 push or pull onto or into the membrane, resulting in a
deformation of the membranes 4705 and 4706, respectively. This
deformation results in movement of the filler material and, a
change in the shape of the lens, and consequently a change of the
optical properties of the lens. One advantage of this approach is
that the fixed position of the lens shapers act to reduce tolerance
requirements on the movement. To further reduce the lateral
dimension of the lens assembly it is also possible to use the ring,
which is pushing onto the membrane as a lens defining ring as
described elsewhere herein. Such an approach may save space for the
lens shaper.
[0350] The inner portions of the reservoirs (i.e. the volume
defined by the inner perimeter of the lens shapers projected toward
the base of their respective containers) define lenses 4731 and
4735 and the three-dimensional shape of the lenses 4731 and 4735
can be varied. For example, spherical lenses (e.g., convex and
concave), aspherical lenses (e.g., convex and concave), cylindrical
lenses (e.g., defined by a square lens shaper instead of round),
flat lenses, and any micro lenses (e.g., a micro lens array or a
diffraction grating), and nano lens structures (e.g. including
antireflection coating), which can be integrated or attached to the
optically active section of the lens can be created. Other examples
of lens shapes can be created. Inhomogeneous material thickness,
hardness or prestretching of the membranes may also be used to
alter the optical properties of the lens.
[0351] The assembly 4700 may be combined with other focus tunable
and non-focus tunable lenses, filters and any other combination of
optical systems, including mirrors, gratings, prisms, and
apertures. The assembly 4700 can be used with other elements as
well.
[0352] In one example of the operation of the system of FIGS.
47A-4D, application of a driving signal voltage to the
piezoelectric motors 4742, 4743, 4744, and 4753 results in a
movement of the rings 4714 and 4715 (e.g., upward or downward,
depending on the shape, timing, frequency and/or other
characteristic of the applied electrical signal). The shape and
other characteristics of the electrical control signal may be
controlled and provided to the motor by any number of devices or
approaches. For example, a user may manually press a switch,
button, or other control device or interface to control the
voltage. In another example, voltage may be controlled by a program
or algorithm (e.g., an autofocus or zoom program or algorithm).
[0353] Referring now to FIGS. 53A-D, the waveform applied to the
stick-slip motor may be a sawtooth waveform. As shown in FIG. 53A,
the linkage element 5302 may be pushed by the motor leg 5304 during
the slow-rising portion of the waveform (as it is applied to the
motor at point 5306) and sticks when the waveform drops. At point
5308, sticking is still occurring (See FIG. 53B), but slipping
occurs at point 5310 (see FIG. 53C). Sticking occurs at point 5312
(see FIG. 53D). Applied waveforms may be high frequency waveforms
(e.g., 320 kHz) and different resonant frequency modes of the
piezoelectric motor are actuated to accomplish movement in a
preferred direction.
[0354] Referring now to FIGS. 48A-C, still another example of a
lens assembly 4800 is described. The lens assembly 4800 includes a
housing 4802, a top and bottom lens shaper 4822 and 4823,
respectively, a top and a bottom container 4803 and 4804,
respectively, a piezoelectric motor 4842 and a ball bearing with
balls 4808 and fixtures 4807, a top membrane 4805 and a bottom
membrane 4806. A top filler volume 4817 is formed between the top
container 4803 (e.g., a glass plate) and the first membrane 4805. A
bottom filler volume 4818 is formed between the bottom liquid
container 4804 and the second membrane 4806 and is filled with a
filler material. A central opening 4830 extends in an axial
direction (in the direction of the z-axis) through the assembly
4800. Light rays 4850 are representative of an image move through
the central opening 4830 in the lens structure in the axial
direction. Once acted on by the components of the lens structure, a
sensor 4852 (e.g., a capacitive charged device (CCD)) receives and
senses the image conveyed by the light rays 4850.
[0355] In this example, three piezoelectric motors are used. More
specifically, the top lens shaper is moved by a first piezoelectric
motor 4842. The bottom lens shaper is moved by second piezo motor
(not shown) and a third piezoelectric motor 4844 and guided by a
ball bearing 4808. The second and third piezoelectric motors 4844
can be controlled individually (and also separately from the first
piezoelectric motor 4842), resulting in the ability to not only
axially move the lens shaper, but also tilt the lens shaper. This
technique can be used to achieve image stabilization and also to
compensate for assembly tolerances.
[0356] The inner section of the membrane and the outer section may
be made of one type of membrane material. However, in other
examples the outer section of the membrane and the inner section
are constructed of different membrane materials. The membranes 4805
and 4806, the reservoirs 4812 and 4813, and the top and bottom
containers 4803 and 4804 can provide various reflective,
refractive, diffractive, and absorptive, or color filtering
functions for the overall system. Other examples of functions may
be provided by the membranes/reservoirs.
[0357] The shape of the lens can be varied to produce various types
of lenses. For example, spherical lenses (e.g., convex and
concave), aspherical lenses (e.g., convex and concave), cylindrical
lenses (e.g., defined by a square housing instead of round), flat
lenses, micro lenses (e.g. micro lens array, diffraction grating),
and nano lens structures (e.g. including antireflection coatings)
that can be integrated or attached to the optically active section
of the lens can be created. Other examples of lens structures are
possible. Inhomogeneous material thickness or hardness for the
membranes 4805 and 4806 may also be used to alter the optical
properties of the lens.
[0358] The assembly 4800 may be stacked in any combination with the
above-described focus tunable lens, such as, for example, with
other focus tunable and non-focus tunable lenses, filters and any
other combination of optical systems, including mirrors, gratings,
prisms, shutters, image stabilizers, and apertures. The assembly
4800 may be configured with other elements as well.
[0359] In one example of the operation of the system of FIGS.
48A-C, an electric signal can be applied to one or all of the
piezoelectric motors. The electrical signal provided may be
controlled by any number of devices or approaches. For example, a
user may manually press a switch, button, or other actuator to
control the applied voltage. In another example, voltage may be
controlled by a program or algorithm (e.g., an autofocus program),
which adjusts automatically the voltage supplied to the
piezoelectric motor. The direct interaction of the piezoelectric
motor with the lens shaper results in an axial movement of the lens
shaper 4822 or 4823 along the z-axis. Movement of the lens shapers
4822 and 4823 displaces the filler material (e.g., optical fluid)
in the filler volumes, thereby altering the overall lens shape and
the optical properties of the lens.
[0360] As mentioned, the membranes as described herein can be
produced by using various methods and manufacturing techniques. For
example, the membranes can be formed using knife coating,
calendaring, water-casting, injection molding, nano-imprinting,
sputtering, hot embossing, casting, spin-coating, spraying, curtain
coating, and/or chemical self-assembly techniques. Other examples
are possible.
[0361] The membranes can also be constructed from various
materials. For example, the membranes can be constructed from gels
(for example, Optical Gel OG-1001 by Litway); polymers (e.g., PDMS
Sylgard 186 by Dow Corning, or Neukasil RTV 25); acrylic materials
(e.g. VHB 4910 by the 3M Company); polyurethane; and/or elastomers
to name a few examples. In many of these examples, the membranes
are constructed from a material through which air (but not liquids
or gels) can pass. Other examples are also possible.
[0362] Additionally, in some examples, the membranes are
pre-stretched. This technique may provide an improved optical
quality and faster response in movement or deformation of the
membrane. For example, the membrane may be mounted in a
prestretched manner under elastic tension. The membrane may be
stretched in stages such that the elastic tension of the inner area
of the membrane is less than the tension in the outer area of the
membrane. In other embodiments, prestretching is not used.
[0363] Referring now to FIG. 49, another example of a lens assembly
4900 is described. A housing 4901 encloses a container 4903 and a
portion of the housing 4901 also functions as a lens shaper 4922. A
piezoelectric motor 4942 is coupled to the container 4903. A
membrane 4905 holds filler material 4912 in a filler volume 4917
between the membrane 4905 and the container 4903. The filler volume
4917 has an inner section or lens portion 4931 and an outer section
or reservoir portion 4921. Ball bearings 4907 are used to reduce
frictional forces and prevent the tilting between the housing 4901
and the container 4903. The detailed construction and placement of
the above-mentioned elements have been described elsewhere herein
and will not be repeated here.
[0364] The piezoelectric motor 4942 is coupled to the container
4903. The coupling may be by glue or any other suitable fastener
mechanism or fastening approach. The housing 4901 has an integrated
lens shaper 4922 and the housing 4901 is moved by the piezoelectric
motor (e.g., with a stick-slip motion) between the piezoelectric
motor 4942 and the housing. The movement of the housing 4901
results in movement of the filler material 4912 within the filler
volume 4917 and the deformation of the membrane 4905. Consequently,
the optical properties of the inner section 4931 changes.
[0365] Referring now to FIGS. 50A-B, another example of a lens
assembly 5000 is described. The assembly 5000 includes housings
5001, 5002 that enclose a lens shaper 5022, a container 5003, a
membrane 5005, filler material 5012, a filler volume 5017 (formed
between the membrane 5005 and the container 5003), a ring 5014, and
a piezoelectric motor 5042. The construction and placement of these
elements have been described previously and will not be described
again here. In this example, the piezoelectric motor 5024 and pin
5016 act as a screw-drive motor. The piezoelectric motor 5042 is
coupled by a pin 5016 and engaged in a hole in ring 5014. Rotation
of the pin 5016 pushes or pulls the ring 5014 at the area of
engagement in the direction indicated by the arrow 5024. The ring
5014 is coupled to/is incorporated with a flexible hinge 5028 that
allows bending of the ring along the hinge 5028.
[0366] In this example and as compared to some other examples
described herein, the use of ball bearings is eliminated thereby
reducing the part count. The membrane 5005 is deformed by moving
the ring 5014 on one side (with an upward and downward movement
indicated generally by an arrow labeled 5024) using the
piezoelectric motor 5042. On the opposite side, the ring 5014 is
attached to the housing 5002. As mentioned, the ring includes a
flexible hinge 5028 that allows bending to occur. When the ring is
moved by the piezoelectric motor, it is tilted (with respect to the
z-axis) and pushes and pulls the outer section of the membrane 5005
and this, in turn deforms the outer section of the filler volume
5017 and changes the shape of the inner section or lens portion
5031 of the filler volume 5017. Movement may be accomplished along
the arrows labeled 5049 and 5024.
[0367] The tilting of the ring 5014 does not affect the optical
qualities of the lens portion 5031, because the lens portion shaper
5022 defines the deformable lens 5031. Instead of utilizing the
hinge 5028, the apparatus of FIGS. 50A-B may also allow the fixed
side of the tilting ring to rotate about a point as shown in FIGS.
50C-D. Referring now specifically to FIGS. 50C-D, The ring 5014 may
be fixed at point 5057 and as pin 5014 moves upward and downward in
the direction indicated by the arrow labeled 5024, the ring rotates
in the direction indicated by the arrow labeled 5049.
[0368] The piezoelectric motor 5042 turns a pin 5016 and the pin is
engaged to a hole in the ring 5014. The turning of the pin 5016
caused by a stick-slip or multi-modal vibration in the
piezoelectric motor 5042 pushes or pulls the ring 5014 in an upward
or downward direction generally as indicated by the arrow indicated
by the label 5024. Alternatively, the pin 5016 and the
piezoelectric motor 5042 may be a single element and connected
directly to the ring 5014. It will be appreciated that the examples
of FIG. 50A-D are particularly advantageous for focusing lenses
that require less tuning than zoom lenses.
[0369] Referring now to FIGS. 51A-B, another example of a lens
assembly 5100 is described. The assembly 5100 includes housings
5101, 5102 that enclose a lens shaper 5122, a container 5103, a
membrane 5105, filler material 5112, a filler volume 5117 (formed
between the membrane 5105 and the container 5103), ball bearings
5107 and a piezoelectric motor 5142. These elements have been
described previously (e.g., with respect to FIGS. 45 and 46) and
will not be described again here.
[0370] In this example, the shape of the piezoelectric motor 5142
is configured so as to grip or clamp the container 5103 (e.g., in a
U-shape). More specifically, an extension member 5125 of the
container 5103 is clamped by the piezoelectric motor 5142. When
actuated, the piezoelectric motor 5142 moves the extension member
5125 (and hence the entire container 5103) upward and downward
(e.g., according to stick-slip motion). As described, this motion
of the extension member 5125 impacts the filler volume 5117 to move
the membrane 5105 and alter the shape of the inner section or lens
portion 5131. This, in turn, changes the optical properties of the
lens portion 5131 (the portion that optically acts on light rays
5150 passing through the lens assembly 5100).
[0371] Referring now to FIG. 52A, one example of an asymmetrically
designed lens module 5200 (e.g., such as that used with a camera)
is described. A first connector linkage 5259 (and a step element
5262) and a second connector linkage 5261 connect a paddle 5258 to
a piezoelectric motor 5242. Linkages 5259 and 5261 can be part of
the paddle 5258, the piezoelectric motor 5242, or independent
parts. The linkages 5259 and 5261 function to transmit force from
the piezoelectric motor 5242 to the paddle 5258. The step element
5262 is inserted into or coupled to the paddle 5258 so that the
connection can be made without contacting the outer portion 5255 of
a membrane 5205 or the container 5203. A membrane 5255 is disposed
between the paddle 5258 and top container 5203. The container 5203
may be a plastic part or a glass plate to name two examples of
container configuration. A bottom container 5204 is also disposed
within the assembly 5200. It will be appreciated that a second
membrane/paddle arrangement including the bottom container may also
be used but is for simplicity not shown in FIG. 52A. A corrective
lens barrel housing 5263 houses the above-mentioned elements. In
this configuration, it is shown as integral portion of the top
container 5203 and the bottom container 5204. The lens barrel
housing 5263 also includes fixturing for corrective optical
elements and corrective optical elements (not shown). In one
example, the aperture is molded as an integral part of the lens
barrel but this is not required.
[0372] The paddle 5258 is mechanically interconnected or coupled to
both the motor and the fluid. In one example, the paddle 5258 is
flat and may include stiffening ribs. The shape and size of the
paddle 5258 can be optimized to communicate forces (e.g., push) on
the filler material efficiently. In this example, the paddle
includes legs 5264. The legs 5264 allow paddle-to-filler
interaction to be low when the movement of the paddle is slow and
allow the paddle-to-filler interaction is high when the movement is
faster.
[0373] The membrane 5205 is divided by a lens shaper (not shown)
into an inner section 5265 and an outer section 5255. The edge of
the inner section of the membrane which contacts the lens shaper
constrains the membrane by defining the outer shape of the lens.
Hinges 5228 and 5229 are coupled to the paddle 5258 and the top
container 5203. In this example, the hinges are disposed at a
discrete point at the end of the legs 5264. The hinges 5228 and
5229 could be made from a variety of different materials such as
glue, membrane material, and may be disposed at a pocket in the
container 5203. The hinges 5228 and 5229 could be made from the
legs 5264 and extend upward into the leg 5264 by making the leg
5264 flexible. The hinges 5228 and 5229 could be part of the
container 5203.
[0374] Referring now to FIG. 52B, the apparatus of FIG. 52A is
shown with the apparatus pushing the lens outward and increasing
its curvature. More particularly, the piezoelectric motor pushes on
a linkage 5259 that is mechanically connected to the paddle 5258,
which pushes into the container 5203 and pushes fluid into the lens
5235 changing its shape. The membrane 5205 containing the filler
stretches at points labeled as 5280, 5281 and 5282. The membrane
5205 is held in place at the outer edge at the points labeled as
5283 and 5284.
[0375] The membrane 5205 is held in place at the points labeled as
5285 and 5286 and these are also the locations that define the
outer edge of the lens shape. As shown, the membrane 5205 is
disposed between the paddle 5258 and the container 5203. This
positioning is advantageous during manufacturing since it allows
for ease of construction of the assembly 5200. In another example,
the paddle 5258 pushes directly on the container 5203.
[0376] Referring now to FIG. 52C, the apparatus of FIGS. 52A and
52B is shown pushing the lens inward producing a lens shape that is
concave in shape instead of convex in shape. It will be appreciated
that bi-directional movement of the filler material within the
reservoir formed between the membrane 5205 and the container 5203
may be employed but is not required. For instance, depending on the
amount of initial filling of the reservoir, the lens could change
curvature rather than allow for movement. It is shown here in this
example as changing from a convex shape to a concave shape.
[0377] The motor pushes on a linkage 5259 that is mechanically
connected to the paddle 5258 pushes into a container 5203 and
pushes filler (e.g., optical fluid) into the lens 5235 changing its
shape. The membrane 5205 containing the fluid stretches at 5280,
5281, and 5282. The membrane 5205 is held in place at the outer
edge at points labeled as 5283 and 5284. The membrane 5205 is held
in place at the points labeled as 5285 and 5286 and this is also
the location that defines the outer edge of the lens shape.
[0378] Referring now to FIGS. 54A-D, another example of a
mechanical linkage for moving the liquid containers axially with
respect to the lens shapers is described. It will be appreciated
that some elements of the lens assembly already discussed herein
are omitted from FIGS. 54A-D for clarity. In this example, an
electrical-to-mechanical actuation device 5467 capable of
independently and simultaneously deforming in two dimensions is
disposed on one wall of the lens assembly housing (not shown for
clarity.) For example, this actuation device may comprise an
electroactive polymer which deforms in the horizontal direction
when a voltage is applied across a set of electrodes 5468 and in
the vertical direction when a voltage is applied across a second
set of electrodes 5469.
[0379] The actuation device 5467 is affixed to a bottom ring 5415
at drive point 5470. A mechanical linkage 5471 having an
articulated member 5472, a rigid member 5473, and a pivot 5474
couples vertical motion of the actuator 5467 at the drive point
5470 to vertical movement of the bottom ring 5415 and horizontal
actuation to vertical movement of the top ring 5414. Articulation
in the linkage 5471 and guide brackets 5475 and 5476 are used so as
to not over constrain the mechanical system and bind all intended
motion.
[0380] The articulated member 5472 is coupled to the bottom ring
5415 via a guide bracket 5476 affixed to the bottom ring 5415. The
rigid member 5473 is similarly connected to the top ring 5414 via a
top guide bracket 5475 affixed to the top ring 5414.
[0381] Upon actuation in the vertical direction, the bottom ring
5415 is moved in a vertical direction. The articulated member 5472
is free to move horizontally within the bottom guide bracket 5476
so as to couple this motion into the rigid member 5473. Upon
actuation in the horizontal direction, the articulated member 5472
slides freely through the bottom guide bracket 5476 and rotates the
rigid member 5473 about the pivot 5474, thus causing a vertical
motion of the rigid member 5473 at the top guide bracket 5475. The
top guide bracket 5475 permits the rigid member 5473 to rotate
freely. The vertical motion of the rigid member 5473 at the top
guide bracket 5475 is coupled to the top ring 5414.
[0382] The operation of the mechanical linkage 5471 is further
illustrated in FIG. 54B-D. In the unactuated state of the actuation
device in FIG. 54B, the mechanical linkage holds the rings in a
rest position. Upon vertical actuation at the drive point 5470,
shown in FIG. 54C, the articulated member 5472 moves with the
bottom ring 5415 with minimal coupling to the rigid member 5473.
Upon horizontal actuation at the drive point 5470, shown in FIG.
54D, the articulated member 5472 pushes horizontally on the rigid
member 5473, which rotates about the pivot 5474 and results in a
vertical motion at the top guide bracket 5475.
[0383] Those skilled in the art will recognize that this example
linkage will only approximately allow independent motion of the top
and bottom rings 5414 and 5415. Some motion of the bottom ring 5415
is likely to couple to motion of the top ring 5414 and vice-versa.
The linkage 5471 is intended to minimize this effect. Alternative
mechanisms are contemplated for independently, or approximately
independently, coupling a two-degree-of-freedom actuation device to
two members moving along a common axis.
[0384] FIG. 55A shows a portion of a lens module 5500 having a
variable optical lens 5531. The module 5500 has an electrical to
mechanical actuation mechanism utilizing linkages to a fluid system
and the variable optical lens 5531. Housings and connections are
not shown in whole in FIG. 55A; only the connection points are
provided in order to isolate this description to the actuation
mechanism.
[0385] A connection 5587 is provided between the housing (not
shown) and a paddle 5558. The paddle 5558 may have a substantial
"U" shape, although other shapes are contemplated. The legs 5564
may be spaced apart to fit around the lens 5531. The connection
5587 may be, for example, in a form of a ball bearing structure or
mechanical guide which could allow for a vertical movement of the
paddle 5558. The connection 5587, in another embodiment, could also
be a hinge. More specifically, the hinge may be a living hinge made
from the same material used to construct the paddle. In an
embodiment, the hinge is constructed from a different material,
such as, for example, an additional portion of plastic. In yet
another embodiment, the material could be elastomeric, an adhesive,
or other like material capable of providing the desired properties
of a hinge. This type of connection 5587 or joining may lead to
generally rotational movement of the paddle 5558 about the
connection 5587. In another embodiment, the connection 5587 could
be a pocket or groove into which the legs 5564 of the paddle 5507
could fit. This embodiment may reduce or eliminate the need for an
adhesive or additional connection structure. It could be a
connection 5587 to which, for example, a damping compound is added.
This will lead to generally rotational movement; however, the
pockets or grooves could be designed for other types of movement.
The connection 5587, in yet another embodiment, could be a hinge or
round portion positioned into a round slot to allow for convenient
rotation.
[0386] A filler volume 5517 may be formed between the paddle 5558
and the container 5503. The filler may be displaced towards or away
from the lens 5531 as a result of movement of the paddle 5558. A
drive linkage 5559 may be provided which connects the motion of a
transducer or motor (electrical to mechanical) 5542 to the paddle
5558. The linkage 5559 may be, for example, a shaft, threaded rod,
or other type of linkage. The motor 5542 may be, for example, a
miniature stepper motor, brushless motor, piezoelectric motor,
electroactive polymer motor, or any other type of transducer
capable of providing the desired function. In the embodiment
illustrated in FIG. 55A, the motor 5542 turns or pushes a linkage
5559. In an embodiment, the motor 5542 could be a screw drive
turning linkage 5559, and linkage 5559 could be a threaded rod
engaged in a threaded section 5588 of paddle 5558. In another
embodiment, this area 5588 of the paddle 5558 may have or form a
pocket or groove to allow the linkage 5559, which could be
contoured or rounded to fit within the engagement area 5588, to
push or pull the paddle 5558.
[0387] Location of the engagement feature 5588 on the paddle 5558
may affect the leverage that is obtained when the motor 5542 is
actuated. For example, a motor 5542 capable of delivering high
force over a small displacement may be used optimally when the
engagement feature 5588 is close to the connection 5587, where a
motor 5542 capable of delivering low force over larger displacement
may be used optimally with the engagement feature 5588 is more
distant from the connection 5588. The shape of the paddle 5558 may
be designed to distribute the pushing or pulling force over the
membrane 5505 to increase the mechanical efficiency of the
structure.
[0388] FIG. 55B illustrates another embodiment in which the paddle
5558 is actuated by the motor 5549. In this embodiment, the paddle
5558 has an extension 5589 which extends substantially non-parallel
to a plane defined by the body of the paddle 5558. The extension
5589 may have an engagement feature 5588 which is pushed or pulled
by the linkage 5559. The linkage 5559 connected to the motor 5542
may have a contoured or rounded end to mate with the engagement
feature 5588. By providing this type of interface, movement of a
transducer is not in the same plane as the movement of the paddle
5558. This changes the leverage and provides potential space
optimization. Other linkages and/or interfaces are possible,
including, but not limited to, simple frictional attachments. It is
further appreciated that any combination of single, dual, or
multiple lens assemblies, utilizing single, dual, or multiple
motors are contemplated as necessary for a given application, such
as, for example, a single lens assembly (i.e., a single variable
lens) being used for focusing and/or zooming. In other embodiments,
two or more assemblies, in combination, may be used for carrying
out these functions.
[0389] Referring now to FIGS. 56A and 56B another example of a lens
assembly is described. The lens assembly includes a container that
has a first section 5601, an optically transparent section 5612, an
optical fluid 5616, a membrane 5608, a lens shaper 5602 having gas
exchange hole 5615, a cover plate 5613 (e.g., constructed of
glass), a bottom housing 5606, a top housing 5605 connected by a
thread 5631 and a tolerance absorbing ring 5630. The absorbing ring
5630 may be a ring approximately 0.2 mm in thickness and
constructed from silicone, polyurethane or acrylic material. Other
dimensions and materials can also be used to constrict the ring
5630. The other elements of the figure have been discussed above
and function generally in the same way as described previously.
[0390] By adjusting the distance between the first section 5601 and
the lens shaper 5602 using the screwing mechanism between bottom
housing 5606 and the top housing 5605 and the soft tolerance
absorbing ring 5630, which is compressible (and decompressable) in
the direction indicated by the arrow labeled 5632, production
tolerances in the fill volume of the fluid 5616 and the container
volume can be compensated. The adjustment occurs by mechanical
adjustment that may be made manually or by an automated device.
Other adjustment approaches may also be used. In these approaches,
easy adjustment of the initial focal length of the lens system
after filling is accomplished by making the above-mentioned
adjustment along the direction indicated by the arrow labeled
5632.
[0391] Referring now to FIG. 57A and FIG. 57B another example of a
lens assembly 5700 is described. As shown in FIG. 57A, the lens
assembly 5700 consists of a lens barrel housing 5704 which contains
a number of lenses 5705, 5706 and 5707, which are used for image
correction purpose. These lenses can be constructed from a plastic
such as Polycarbonate, Polystyren or other optically clear plastic
materials. Other examples of materials can also be used. An
optically clear liquid 5702 (or other filler material) is enclosed
by a deformable membrane 5701 and an optically transparent
container 5703. The container 5703 and the housing 5704 are
interconnected to each other via mechanical interlocking or gluing.
The central part of the housing 5710 is in contact with the
deformable membrane 5701 and defines the shape of the membrane. A
coil 5708 is connected to the deformable membrane 5701. The
magnetic field indicated by the label 5711 of magnet 5709 interacts
with the electrical current flowing through the coil 5708 resulting
in an axial force on the coil in the direction of the arrow labeled
5712. This force translates in deformation of the membrane 5701 and
thus changing the shape of central, optically active part of the
deformable membrane 5701 acting on the light rays 5713. This
embodiment requires only a very small number of parts, enabling a
very cost efficient autofocus module. Additionally, it is very
tolerance insensitive.
[0392] FIG. 57B describes a similar embodiment with one difference
being that the magnet 5709 is moving and the coil 5708 is fixed on
the lens barrel housing 5704. All the other elements shown in FIG.
57B are the same as FIG. 57A and perform similar functions.
[0393] Referring now to FIG. 58A, one example of a symmetrical
actuator is described. The structure surrounds the central axis
5826. The structure includes a first coil 5802, a second coil 5804,
a first magnet 5818, a second magnet 5820, and a third magnet 5822.
When wires in the coils 5802 and 5804 are excited by an electrical
current, the coils 5802 and 5804 interact with a magnetic flux as
shown that is directed by a bottom return flux guiding structure
5806, a top return flux guiding structure 5808, a side return flux
guiding structure 5810 in a direction indicated by the arrows
labeled 5812. By reversing the polarization of all the magnets the
flow, would be equivalent but reversed. The side return magnetic
flux guiding structure 5810 includes a side return overhang portion
5824 to help absorb the manufacturing tolerances associated by the
parts and/or control stray fields More or less overhang would not
change the basic principal of operation of this example. The
magnets, coils, and magnetic flux return structures can be
implemented as described elsewhere herein.
[0394] In the example of FIG. 58A, a significant portion of the
flux lines flow through the coils 5802 and 5804 substantially
perpendicular to the direction of the current flow. In other words,
a structure is created that contains stray field and focuses field
at the coil with the appropriate angular relationship and thus
generates an optimized amount of force for the given space. The
flux is concentrated in the path indicated by the arrows labeled
5812. As a result, the coils 5802 and 5804 receive a sufficient
force to be moved and/or move other elements that adjust
characteristics of the lens as has been described previously
herein.
[0395] Referring now to FIGS. 58B and 58C, another actuator is
described. The actuator includes a first coil 5856, a first magnet
5852, a second coil 5858 and a second magnet 5854. The actuator is
disposed in close proximity to containers 5864 and 5866 (described
elsewhere herein) and near outer light rays within the primary
optical path 5868 in 58B and 5880 in 58C. The interaction of the
magnets 5852 and 5854 and the electric current as it is applied to
the wires in the coils 5856 and 5858 interacts with magnetic flux
lines that flow in the directions indicated by the arrows labeled
5872, 5874, and 5876. The flux lines flow through the optical
structure of the lens that may include the containers 5864 and 5866
and some lines of the flux will cross into the primary optical path
5868. FIG. 58B shows the primary flux paths 5872, 5874, 5876 and
FIG. 58C shows the secondary flux paths. The magnets, coils, and
magnetic flux return structures can be implemented as described
elsewhere herein.
[0396] A first (top) portion of the bottom magnet 5854 share flux
lines created by a second (bottom) portion of the top magnet 5852.
As shown, flux lines are reused and reinforced as between the
magnets 5852 and 5854 and become part of the same magnetic circuit.
The bottom magnet 5454 provides a path with less magnetic
reluctance for the top magnet 5852 than would be provided without
the bottom magnet 5854. As a consequence, an efficient actuator
structure is provided that produces sufficient force to move the
coils 5856 and 5858 (that directly or indirectly move the membranes
as described elsewhere in this application) and, at the same time,
is small enough to fit into extremely confined and discontinuous
spaces remaining after placement of the optics within the
assembly.
[0397] It will be appreciated that although the actuators described
in FIGS. 58A and 58B (as well as elsewhere herein) are shown as
being part of a lens assembly, the actuators can be used with
respect to other types of devices and with a wide variety of other
applications. For example, the actuators may be used in conjunction
with speakers (e.g., to move tweeter and woofer speakers to mention
one example). Other examples are possible. In fact, the actuators
described herein can be used to supply force to any suitable
component of any type of system or any type of application.
[0398] FIG. 58D shows an example of the optical portion of the
assembly. This example includes a top variable optical assembly
5890 which contains a membrane 5892, optical filler material 5893,
container 5891 and a corrective lens 5894 embedded in the container
5894. This assembly 5890 is the farthest optical component away
from the sensor 5899. This approach allows for an assembly that
will maximize performance while minimizing height from sensor 5899
to cover 5898 (e.g., cover glass). A further aspect is having
optical elements 5894 imbedded into the container 5891. In this
example, the second lens is a push-pull (convex-concave) lens
allowing a very compact optics design.
[0399] In the examples of FIGS. 58A-58D, the magnetic structures
are coupled together and also coupled through one or more optical
elements of the system (e.g., through the lens, containers, or
membranes). Very small air gaps in both motor structures. The side
return structures may be self-attaching to the housing thereby
providing easy assembly with no adhesive (e.g., glue) required.
These approaches are also fault tolerant from an assembly point of
view, since a loose positioning of the magnetic structure will only
minimally reduce the magnetic force generated by the coils.
Additionally, the magnets are well defined and the posts in the
housing define the location of the magnets.
[0400] Referring now to FIGS. 59A and 59B, an example of a lens
assembly 5900 is described. The lens assembly includes a top
housing 5905, a top container 5904, a top magnetic return structure
5926, an aperture 5921, a cover plate 5901, filler material 5903, a
membrane 5902, a corrective lens 5925, a magnet 5914, a top bobbin
5912, a top coil 5913, a return structure 5915, a flex circuit
conduit 5920, filler material 5906, a magnet 5919, a bottom bobbin
5916, a bottom coil 5917, a magnetic flux return structure 5918, a
sensor cover 5911 (e.g., a glass plate), a membrane 5908, a bottom
housing 5910, a meniscus lens 5909, and a bottom container
5907.
[0401] The construction, operation, and interaction of these
components have generally been described elsewhere herein and will
not be described again here. Additionally, it will be appreciated
that one example of the operation and actuation has been described
above with respect to FIG. 58B.
[0402] As shown in FIG. 59B, the flex circuit 5920 is coupled to a
connector 5922. A flexible electrical connector 5921 (e.g., a wire)
extends from the connector 5922 and is wound around the bobbin 5916
to form the coil 5917. Thus, current flows from an outside current
source (not shown), to the flex circuit 5920, through the connector
5922, through the conductor 5921, around the coil (surrounding the
bobbin), and back out through the flex circuit 5920. The wire
connection for coil 5913 is through the flex and the connector 5924
guided down to the flex through the post 5923.
[0403] The conductors 5921 are free moving and absorb only little
force while moving. The conductors 5921 are disposed so as to
provide for space-saving capabilities with respect to the top coil
and also provide for safety because the conductors 5921 pass
through a protection channel to guide them to the external source
or connection.
[0404] Bottom conductors on the bottom coil 5917 slide under the
magnet 5919 and reside a substantial distance away from the
membrane 5908. A gap in the bottom housing 5910 allows easy guiding
of the conductors to the external source.
[0405] As shown, the top bobbin 5912 includes four finger elements
to hold the top coil 5913. This construction approach provides for
a shock absorption capability and a space saving property allowing
for a smaller assembly to be constructed than would be the case if
the top bobbin were not so constructed. This bobbin configuration
also enables the optics to be positioned closer to the top cover
5901. Generally speaking, the earlier (i.e., closer to the top) the
first tunable lens is located in the optical path, the shorter the
module can be constructed because the light can be reshaped at the
earliest possible position.
[0406] Temperature improvement is provided because the coil 5913 is
positioned a substantial distance away from the membrane and filler
material but close to heat conducting external metal. The square
shape of the bobbin 5912 maximizes length of wire in magnetic
field. Corners of square-shaped bobbins are not generally flux
efficient and therefore this approach provides for posts in the
corner to improve efficiency. Post configuration with square bobbin
5912 also minimizes the space between magnet 5914 and the flux
guiding structure 5915 and reduces costs because the wires does not
need to be glued or attached with some other adhesive. The
spider-like fingers of the bobbin 5912 provide for the shortest
distance between membrane pushing ring and coil holding
structure.
[0407] The bottom bobbin 5916 is mechanically interconnected to the
membrane 5908. The bobbin 5916 has a large travel range and has
almost same force due in part to long magnet 5919 and relatively
straight field lines created.
[0408] The top housing 5905 is a barrel design and includes all
lenses except the meniscus lens 5909. The top housing 5905
additionally provides lens shaper functions. One side of housing
references most of the optical components (e.g., providing parallel
referencing) enabling a single pin-mold and thus providing better
concentricity and tolerances The top housing 5905 protects the coil
5913 from mechanical shock (i.e., the coil 5913 is mechanically
constrained). Additionally, the top housing has holes enabling air
flow from the optical section into the motor section and thus
providing integral barometrical relief function. The bottom tunable
lens is a push-pull lens (as has been described elsewhere herein)
using the lens shaper and retainer mechanism/support member as
shown in FIGS. 41A and B. The variable radius of lens not only
changes the shape of the lens but mechanical clamping structures
may also provide this function. When deforming the lens, not only
the shape of the lens changes but also its axial position as well
as the radius.
[0409] The meniscus lens 5909 is disposed tightly to the housing
5910 that is directly connected to the image sensor making it cost
efficient and tolerance insensitive. The corrective lens 5925
(which may be any corrective optical element constructed of any
material) is disposed in the container 5904. In this respect, the
corrective lens 5925 is integral with the filler-filled lens
structures described herein.
[0410] So assembled, the assembly 5900 includes first tunable lens
(including elements 5903, 5902, 5904, 5912, and 5913) for focusing
of light rays that enter through cover 5901. A second tunable lens
(including elements 5906, 5908, 5907, 5916, and 5917) is also
provided and is for zooming. Consequently, two different tunable
systems are provided which can be optimized for different
functions, constraints. The corrective lens 5925 corrects optical
error such as spherical aberrations. The meniscus lens 5909 helps
to achieve chief ray angle requirements. In many of these examples,
all optical components described above are circular or generally
circular in shape. However, as required, other shapes may also be
used.
[0411] In these examples, the amount of filler material that causes
deformation of the membrane is constant (however, its relative
displacement within a particular lens changes). The magnets 5914
and 5919 may be polarized providing a field perpendicular to the
coils 5913 and 5917 and the coils 5913 and 5917 and magnets 5914
and 5919 are displaced relative to each other.
[0412] Referring now to FIG. 60, another example of a lens assembly
6000 is described. The assembly 6000 is similar to that described
in FIGS. 59A and 59B and like numbers refer to the same elements.
It will be appreciated that actuation of the actuators of FIG. 60
operates in the manner described above with respect to the
actuators of FIG. 58A. More specifically, the assembly 6000
includes a top housing 6005, a top flux guiding structure 6019, a
cover 6001 (e.g., constructed of glass), filler material 6003, a
membrane 6002, a top container 6004, an outer shield or housing
6030, a pusher 6012, a coil 6013, a magnet 6020, a bottom coil
6017, a bottom magnet 6021, a outer return structure 6015, a bottom
bobbin 6016, a meniscus lens 6009, a bottom container 6007, a
corrective lens 6025, filler material 6006, a membrane 6008, a lens
shaper 6022, a bottom return structure 6018, and a magnet 6014.
[0413] In the example of FIG. 60, interconnections between optical
lenses are minimized because of the lens barrel design meaning that
a majority of the optical elements are referenced to one side of
the housing 6005, minimizing assembly and part tolerance. The
bottom bobbin 6016 is split into two sections, so that the coil
6017 can be added after the stacking of the lens.
[0414] Referring now to FIG. 61, one example of a lens array 6100
is described. The lens array 6100 includes a transparent optical
plate 6101, a container element 6102, a housing 6108, light sources
(e.g., emitting diodes (LEDs)) 6107, lens areas 6106, filler
material 6104 that includes displaced filler material within a
region 6105. In operation, the container 6102 is displacing the
filler material by pushing on this through optical plate 6101. This
creates a pressure to move the filler material 6104 selectively to
and from the regions 6105. In this respect, the regions 6105 (and
shapes of the lenses there-defined) may be the same or different.
Consequently, light transmitted from the light sources 6107 can
have one or more of its properties altered as it travels through
the filler material 6104 and through the plate 6101. The properties
affected may include light distribution, brightness, and color, to
name a few examples. Other examples are possible. The assembly 6100
may be used to provide light in any environment or any context such
as within buildings, outdoors, and within vehicles. The light
sources 6107 may be any light emitting device such as LEDs. The
filler material 6104 may be any type of liquid, gel, polymer,
gaseous or any other deformable filler materials that has already
been mentioned herein. Other actuations approaches (e.g., using
piezo electric elements or mechanical pushing of 6101) as described
herein may also be used in place of the container 6102. The filler
material can be made of one material or a membrane and a liquid
material.
[0415] Referring now to FIGS. 62A and 62B, another example of a
lens assembly 6200 is described. The assembly 6200 includes a light
source 6201 (e.g., a LED), a first optical media 6202 (e.g. gas,
liquid polymer, or glass), a rigid optical element 6203 (e.g., a
lens, diffuser, filter, or grating), a second optical media 6208
(e.g., a gas, liquid polymer, or glass), a reflector 6204 (e.g.,
freeform mirror), a deformable filler material 6205 (e.g., a
liquid, gel, or polymer), and a rigid corrective optical element
6206 (e.g., a lens, diffuser, filter, or grating). When the
corrective optical element 6206 is mechanically or electrically
displaced in axial direction 6209, the filler material 6205 is
deformed, resulting in a deformation at the interface of 6210
thereby changing the direction of the light rays 6207.
[0416] An interface 6210 separating the second optical media 6208
and the filler material 6205 can be a deformable membrane made of
the same or a different material than the second optical media 6208
or the deformable filler material 6205. The assembly of 6200 can be
used for light steering applications such as illumination system.
The assembly of 6200 can be a standalone unit, part of an array or
part of larger optical system.
[0417] Referring now to FIGS. 63A and 63B, another example of a
lens assembly is described. The assembly 6300 includes a light
source 6301 (e.g., a LED), a reflector 6202 (e.g., a freeform
mirror), a deformable filler material 6203 (e.g., a liquid, gel, or
polymer), and a lens shaper 6304. When the lens shaper 6304 is
mechanically or electrically displaced in axial direction 6306, the
filler material 6303 is deformed, resulting in a deformation of the
interface of 6307 and thus change of the light rays 6305.
[0418] An interface 6307 separates the deformable filler material
6303 and the optical media 6308 and the interface 6307 can be a
deformable membrane made of the same or a different material than
the optical media 6308 or the deformable filler material 6303. The
assembly of 6300 can be used for light steering applications such
as illumination system. The assembly of 6300 can be a standalone
unit, part of an array or part of a larger optical system.
[0419] Referring now to FIGS. 64A and 64B, another example of a
lens assembly is described. The assembly 6400 includes a light
source 6401 (e.g. LED), a reflector 6402 (e.g. freeform mirror), a
first optical media 6406 (e.g. gas, liquid polymer, or glass), a
deformable filler material 6403 (e.g., liquid, gel, or polymer),
and a lens shaper 6404. When the lens shaper 6404 is mechanically
or electrically displaced in axial direction 6407, the filler
material 6403 is deformed, resulting in a deformation of the
interfaces 6408 and 6409 and thus the direction of the light rays
6405 changes.
[0420] The interfaces 6408 and 6409 separating the deformable
filler material 6403 and the optical media 6406 and 6410
respectively can be a deformable membrane constructed of the same
or a different material than the optical media 6406, 6403, and
6410. The assembly of 6400 can be used for light steering
applications such as illumination system. The assembly of 6400 can
be a standalone unit, part of an array or part of a larger optical
system.
[0421] Referring now to FIG. 65A, one example of a lens shaper 6500
that can be used with the embodiments herein described. The lens
shaper 6500 includes a first surface 6511 extending from a first
face 6521 having a first perimeter 6501 with a first shape, to a
second face 6522 having a second perimeter 6502 with a second
shape. The first shape and the second shape are different. The
membrane shape is defined the lens shaper. When the lens is changed
from a convex state to a concave state, different perimeters of the
lens shapers define the shape of the membrane and thus the shape of
the deformable lens. The lens shaper 6500 transforms the shape of
the membrane/deformable lens from a large elliptical lens defined
by the perimeter 6501, into a small elliptical lens defined by the
perimeter 6502. Referring now to FIG. 65B another of lens shaper
6510 for use with the examples described herein is described. In
this example, the lens shaper 6510 includes a rectangular first
perimeter 6511 and a circular second perimeter 6512. Depending on
the deformation of the membrane, the membrane shape is defined by
different parts of the lens shaper and thus the shape of the
deformable lens changes from a substantially rectangular lens to a
circular lens.
[0422] While the present disclosure is susceptible to various
modifications and alternative forms, certain embodiments are shown
by way of example in the drawings and these embodiments were
described in detail herein. It will be understood, however, that
this disclosure is not intended to limit the invention to the
particular forms described, but to the contrary, the invention is
intended to cover all modifications, alternatives, and equivalents
falling within the spirit and scope of the invention.
[0423] Preferred embodiments of this invention are described
herein, including the best mode known to the inventors for carrying
out the invention. It should be understood that the illustrated
embodiments are exemplary only, and should not be taken as limiting
the scope of the invention.
* * * * *