U.S. patent application number 17/009538 was filed with the patent office on 2022-03-03 for optical arrangement of adaptive illumination system with variable illuminating angle and vcm motor.
The applicant listed for this patent is ZEBRA TECHNOLOGIES CORPORATION. Invention is credited to Igor Vinogradov.
Application Number | 20220066203 17/009538 |
Document ID | / |
Family ID | |
Filed Date | 2022-03-03 |
United States Patent
Application |
20220066203 |
Kind Code |
A1 |
Vinogradov; Igor |
March 3, 2022 |
OPTICAL ARRANGEMENT OF ADAPTIVE ILLUMINATION SYSTEM WITH VARIABLE
ILLUMINATING ANGLE AND VCM MOTOR
Abstract
A method and apparatus for illuminating at least one object
appearing in a field of view (FOV). An illumination system includes
an illumination source configured to provide illumination to
illuminate a target of the object. A collimating lens is configured
to collimate the illumination and to provide the illumination to a
fixed multiple lens array (MLA). The fixed multiple lens array
provides the illumination to a movable MLA. The movable MLA is
configured to provide the illumination to the target to illuminate
the target. The position of the movable MLA may be adjusted to
alter the illumination full field angle.
Inventors: |
Vinogradov; Igor; (Oakdale,
NY) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
ZEBRA TECHNOLOGIES CORPORATION |
Lincolnshire |
IL |
US |
|
|
Appl. No.: |
17/009538 |
Filed: |
September 1, 2020 |
International
Class: |
G02B 27/00 20060101
G02B027/00; G02B 27/30 20060101 G02B027/30; G02B 3/00 20060101
G02B003/00; G02B 7/02 20060101 G02B007/02; G06K 7/10 20060101
G06K007/10 |
Claims
1. An optical assembly for an adaptive illumination system, the
optical assembly comprising: an illumination source configured to
provide light along an optical axis to provide illumination to a
target, wherein the illumination has an illumination full field
angle; a collimating lens disposed along the optical axis and
configured to receive the light from the illumination source and
further configured to collimate the light; a fixed multiple lens
array disposed along the optical axis and configured to receive the
light from the collimating lens; and a movable multiple lens array
disposed along the optical axis and configured to receive the light
from the fixed lens array, wherein the position of the movable
multiple lens array is adjustable and the position of the movable
lens array may be adjusted to change the illumination full field
angle.
2. The optical assembly of claim 1, further comprising a motor
physically coupled to the movable multiple lens array and
configured to adjust the position of the movable multiple lens
array.
3. The optical assembly of claim 2, wherein the motor is a voice
coil motor.
4. The optical assembly of claim 1, wherein the movable multiple
lens array has a travel distance of between 0.2 and 1
millimeter.
5. The optical assembly of claim 1, wherein the illuminating full
field angle can be changed from 24 degrees to 46 degrees.
6. The optical assembly of claim 1, wherein the illuminating full
field angle is less than 50 degrees.
7. The optical assembly of claim 1, wherein the illumination source
is a light emitting diode.
8. The optical assembly of claim 1, wherein the collimating lens
has a first surface along the optical axis and a second surface
along the optical axis and wherein the first surface is a planar
surface and the second surface is a convex surface having a
positive optical power, index of refraction between 1.4 and 2, and
am Abbe value of between 20 and 70.
9. The optical assembly of claim 1, wherein the fixed multiple lens
array comprises a first surface along the optical axis and a second
surface along the optical axis, and wherein the first surface is a
planar surface and the second surface comprises a plurality of lens
cells.
10. The optical assembly of claim 9, wherein the plurality of lens
cells comprises a plurality of convex lens cells having a lens cell
size of approximately 0.4 millimeters by 0.5 millimeters.
11. The optical assembly of claim 1, wherein the fixed multiple
lens array comprises a plastic material.
12. The optical assembly of claim 1, wherein the movable multiple
lens array comprises a first surface along the optical axis and a
second surface along the optical axis, and wherein the first
surface comprises a plurality of lens cells and the second surface
comprises a planar surface.
13. The optical assembly of claim 12, wherein the plurality of lens
cells comprises a plurality of convex lens cells having a lens cell
size of approximately 0.4 millimeters by 0.5 millimeters.
14. The optical assembly of claim 1, wherein the movable multiple
lens array comprises a plastic material.
15. The optical assembly of claim 1, further comprising a third
multiple lens array disposed along the optical axis configured to
receive the light from the movable multiple lens array, and wherein
the third multiple lens array is further configured to provide the
light to the target.
16. The optical assembly of claim 15, wherein the third fixed
multiple lens array comprises a first surface along the optical
axis and a second surface along of the optical axis, and wherein
the first surface comprises a plurality of concave lenses and the
second surface comprises a planar surface.
17. The optical assembly of claim 15, further comprising a motor
physically coupled to the third multiple lens array configured to
adjust the position of the third multiple lens array.
18. The optical assembly of claim 17, wherein the motor is an
actuator, a voice coil motor, a piezoelectric device, or a
microelectromechanical systems (MEMS) motor.
19. The optical assembly of claim 1, wherein the movable lens array
comprises a first surface along the optical axis and a second
surface along the optical axis, and wherein the first surface of
the movable lens array comprises a plurality of convex lenses and
the second surface of the movable lens array comprises a plurality
of convex lenses.
20. The optical assembly of claim 1, wherein the target is one of a
1D barcode, 2D barcode, QR code, UPC code, or indicia indicative of
an object of interest.
21. The optical assembly of claim 1, wherein the illuminating full
field angle can be changed from 16 degrees to 42 degrees.
Description
BACKGROUND OF THE INVENTION
[0001] Imaging devices generally capture images within a given
field of view (FOV). It is often required that that scanning
devices capture images at various distances and at various fields
of view to effectively decode information in an image for use in
machine vision applications. Additionally, the demand for portable
sensors is increasing which requires the use of smaller sensors
further requiring active alignment of the sensors necessitating an
air gap between optics and the sensor. Accordingly, portable
scanning devices must be capable of functioning with a wide field
of view while generating sharp images over a working range for the
purposes of machine vision.
[0002] Imaging barcode readers require illumination sources to
illuminate a target. Compact imaging systems, such as a compact
barcode reader, may require an internal illumination source which
is often difficult to implement due to size, power requirements, a
desired field of view (FOV), and/or illumination requires. Even
further, typical auto-focus imaging systems, which can focus at a
range of depths and/or FOVs, may not function efficiently with an
internal or external illumination system having a fixed
illumination profile. For example, it may be preferred to have a
wide illumination FOV for reading a barcode at short distances,
while having a narrow illumination FOV for reading barcodes at
farther distances. Typical imaging systems fail at accomplishing
this because many wide FOV illumination systems cannot provide
enough illumination to image a target that is at a farther
distance. While some systems may address these, and other issues,
via a combination of complicated custom optics and bulky
components, such systems are fairly complex, costly, large, and can
adversely impact reliability of the device.
[0003] Accordingly, there is a need for improved systems, methods,
and devices which address these issues.
SUMMARY
[0004] In an embodiment, the present invention is an optical
assembly adaptive illumination of an object of interest. The
optical assembly comprises an illumination source configured to
provide light along an optical axis to provide illumination to a
target, wherein the illumination has an illumination full field
angle; a collimating lens disposed along the optical axis and
configured to receive the light from the illumination source and
further configured to collimate the light; a fixed multiple lens
array disposed along the optical axis and configured to receive the
light from the collimating lens; and a movable multiple lens array
disposed along the optical axis and configured to receive the light
from the fixed lens array, wherein the position of the movable
multiple lens array is adjustable and the position of the movable
lens array may be adjusted to change the illumination full field
angle.
[0005] In a variation of the current embodiment, the optical
assembly further includes a motor physically coupled to the movable
multiple lens array and configured to adjust the position of the
movable multiple lens array, and in an embodiment, the motor may be
a voice coil motor. In a variation of the current embodiment, the
movable multiple lens array may have a travel distance of between
0.2 and 1 millimeter.
[0006] In a variation of the current embodiment, the illuminating
full field angle may be changed from 24 degrees to 46 degrees. In a
variation of the current embodiment, the illuminating full field
angle may be changed from 16 degrees to 42 degrees.
[0007] In a variation of the current embodiment, the collimating
lens has a first surface along the optical axis and a second
surface along the optical axis and wherein the first surface is a
planar surface and the second surface is a convex surface having a
positive optical power, index of refraction between 1.4 and 2, and
am Abbe value of between 20 and 70.
[0008] In a variation of the current embodiment, the fixed multiple
lens array comprises a first surface along the optical axis and a
second surface along the optical axis, and wherein the first
surface is a planar surface and the second surface comprises a
plurality of lens cells.
[0009] In a variation of the current embodiment, the movable
multiple lens array comprises a first surface along the optical
axis and a second surface along the optical axis, and wherein the
first surface comprises a plurality of lens cells and the second
surface comprises a planar surface.
[0010] In a variation of the current embodiment, the optical
assembly further includes a third multiple lens array disposed
along the optical axis configured to receive the light from the
movable multiple lens array, and wherein the third multiple lens
array is further configured to provide the light to the target; and
further wherein the third lens array comprises a first surface
along the optical axis and a second surface along of the optical
axis, and wherein the first surface comprises a plurality of
concave lenses and the second surface comprises a planar
surface.
[0011] In a variation of the current embodiment, the target is one
of a 1D barcode, 2D barcode, QR code, UPC code, or indicia
indicative of the object of interest.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0012] The accompanying figures, where like reference numerals
refer to identical or functionally similar elements throughout the
separate views, together with the detailed description below, are
incorporated in and form part of the specification, and serve to
further illustrate embodiments of concepts that include the claimed
invention, and explain various principles and advantages of those
embodiments.
[0013] FIG. 1 is a schematic side elevation view of an imaging
device having an adaptive illumination system in accordance with
some embodiments.
[0014] FIG. 2 is a schematic top-view of an imaging scanning
station having an autofocus system and an adaptive illumination
system in accordance with some embodiments.
[0015] FIG. 3 illustrates a block connection diagram of system
including an imaging reader.
[0016] FIG. 4A is a cross-sectional side view of an optical
assembly of an adaptive illumination system
[0017] FIG. 4B is a perspective view with ray tracing of the
optical assembly of FIG. 4A.
[0018] FIGS. 5A is a cross-sectional side view of the optical
assembly of FIG. 4A having a motor position distance of 0
millimeters.
[0019] FIG. 5B is an image of the illumination field of the optical
configuration of FIG. 5A.
[0020] FIG. 5C is the illumination full field angle in polar
coordinates for the optical configuration of FIG. 5A.
[0021] FIG. 6A is a cross-sectional side view of the optical
assembly of FIG. 4A having a motor position distance of 0.5
millimeters.
[0022] FIG. 6B is an image of the illumination field of the optical
configuration of FIG. 6A.
[0023] FIG. 6C is the illumination full field angle in polar
coordinates for the optical configuration of FIG. 6A.
[0024] FIG. 7A is a cross-sectional side view of the optical
assembly of FIG. 4A having a motor position distance of 1
millimeter.
[0025] FIG. 7B is an image of the illumination field of the optical
configuration of FIG. 7A.
[0026] FIG. 7C is the illumination full field angle in polar
coordinates for the optical configuration of FIG. 7A.
[0027] FIG. 8 is a cross-sectional view of an optical assembly of
the adaptive illumination system of FIGS. 1 and 2 in accordance
with some embodiments.
[0028] FIG. 9A is a cross-sectional side view of the optical
assembly of FIG. 8 having a motor position distance of 0
millimeters.
[0029] FIG. 9B is an image of the illumination field of the optical
configuration of FIG. 9A.
[0030] FIG. 9C is the illumination full field angle in polar
coordinates for the optical configuration of FIG. 9A.
[0031] FIG. 10A is a cross-sectional side view of the optical
assembly of FIG. 8 having a motor position distance of 0.25
millimeters.
[0032] FIG. 10B is an image of the illumination field of the
optical configuration of FIG. 10A.
[0033] FIG. 10C is the illumination full field angle in polar
coordinates for the optical configuration of FIG. 10A.
[0034] FIG. 11A is a cross-sectional side view of the optical
assembly of FIG. 8 having a motor position distance of 0.5
millimeters.
[0035] FIG. 11B is an image of the illumination field of the
optical configuration of FIG. 11A.
[0036] FIG. 11C is the illumination full field angle in polar
coordinates for the optical configuration of FIG. 11A.
[0037] Skilled artisans will appreciate that elements in the
figures are illustrated for simplicity and clarity and have not
necessarily been drawn to scale. For example, the dimensions of
some of the elements in the figures may be exaggerated relative to
other elements to help to improve understanding of embodiments of
the present invention.
[0038] The apparatus and method components have been represented
where appropriate by conventional symbols in the drawings, showing
only those specific details that are pertinent to understanding the
embodiments of the present invention so as not to obscure the
disclosure with details that will be readily apparent to those of
ordinary skill in the art having the benefit of the description
herein.
DETAILED DESCRIPTION
[0039] Portable high-performance optical imaging systems for
machine vision employ small imaging sensors to maintain small form
factors. For example a typical machine vision imaging sensor has an
imaging sensor rectangular area of around 3 by 3 millimeters with
sensor pixels areas of approximately 3 microns. Some
high-performance compact machine vision systems require wide angle
fields of view (FOVs) (e.g., greater than 40 degrees) in addition
to small form factor imaging sensors. Barcode readers often require
wide imaging FOVs for efficiently reading barcodes at short
distances, while requiring narrower FOVs to efficiently read
barcodes at further distances. The change in the FOV of a barcode
reader changes the pixels per module (PPM) that is able to be
imaged by the barcode reader, and therefore, changes the efficiency
of barcode imaging and reading. Typically, a barcode reader
requires a minimum PPM to properly read a barcode.
[0040] To implement a compact barcode reader or imaging system, an
internal illumination system may be required. It is often difficult
to make an illumination system that meets the wide FOV illumination
requirements of high performance barcode readers, while at the same
time, producing enough light at farther distances to illuminate a
target and properly image and read the target. As described herein,
it may be beneficial to have the ability to increase an
illumination FOV of an illumination system to read barcodes at
short distances, while being able to decrease the FOV of the
illumination system to provide more illumination to a target at a
farther distance to allow for enough PPMs to read barcodes at
different distances.
[0041] The current disclosure describes a compact optical assembly
with an adaptive illumination system. The optical assembly can
change the FOV of the adaptive illumination system according to the
distance of an object of interest. For example, the optical
assembly may include an imaging system having a focus distance to
an object of interest. The illumination system may be configured to
have a wide FOV when the imaging system is focused at a shorter
focal distance, and the illumination system may be configured to
have a narrow FOV when the imaging system is focused at a further
distance, therefore adjusting the amount of illumination received
by the object of interest at different distances from the optical
assembly. The described adaptive illumination system may be
employed in an optical assembly having digital zoom, optical zoom,
auto-focus, variable focus elements, or any other optical assembly
configured to change the imaging focus or to perform optical
detection at different target distances.
[0042] The current disclosure describes an adaptive illumination
system that employs a collimating lens, and a plurality of multiple
lens arrays (MLAs) that improves upon current technologies by: (i)
enabling wide FOV illuminations for objects at a range of
distances, (ii) providing narrow FOV illuminations for objects at a
range of distances, (iii) provides efficient reading of targets are
a large range of focal distances of the imaging system, and (iii)
reduces the size and cost of autofocusing optical imaging systems,
and specifically the illumination system, for machine vision.
[0043] In an exemplary implementation, the present application
provides an optical assembly with an adaptive illumination system
providing adaptive illumination of an object of interest. In
various embodiments of the present disclosure, the optical assembly
includes an illumination source, a collimating lens, a fixed MLA,
and a movable MLA disposed along an optical illumination axis. The
illumination source is configured to provide light along the
optical axis to provide illumination to a target with the
illumination of the target having an illumination full field angle.
The collimation lens is disposed along the optical axis configured
to receive the light from the illumination source and further
configured to collimate the light along the optical axis. The fixed
multiple lens array is disposed along the optical axis configured
to receive the light from the collimating lens, and the movable
multiple lens array is disposed along the optical axis configured
to receive the light from the fixed lens array. The position of the
movable multiple lens array is adjustable and which may be adjusted
to change the illumination full field angle of the
illumination.
[0044] A first embodiment of an imaging device, that may include an
adaptive illumination system as described herein, is shown
schematically in FIGS. 1-3. The imaging device 100 includes a
housing 102, an illumination system 150, and an imaging system 110
at least partially disposed within the housing 102 that includes an
imaging camera assembly. Specifically, the imaging system 110
includes an image sensor 112 and a lens assembly 120. The device
100 may be adapted to be inserted into a docking station 101 which,
in some examples, may include an AC power source 101a to provide
power for the device 100. The device 100 may further include an
onboard power supply 103, such as a battery and a printed circuit
board 106 that may accommodate a memory and a controller that
controls operation of the imaging system 110. In embodiments, the
device 100 may include a trigger (not shown in the illustration) is
used to activate the imaging system 110 to capture an image. The
device 100 may include any number of additional components such as
decoding systems, processors, and/or circuitry coupled to the
circuit board 106 to assist in operation of the device 100.
[0045] The housing 102 includes a forward or reading head portion
102b which supports the imaging system 110 within an interior
region of the housing 102. The imaging system 110 may, but does not
have to be, modular as it may be removed or inserted as a unit into
the devices, allowing the ready substitution of illumination
systems 150 and/or imaging systems 110 having different
illumination and/or imaging characteristics (e.g., illumination
systems having different illumination sources, lenses, illumination
filters, illumination FOVs and ranges of FOVs, camera assemblies
having different focal distances, working ranges, and imaging FOVs)
for use in different devices and systems. In some examples, the
field of view may be static.
[0046] The image sensor 112 may have a plurality of photosensitive
elements forming a substantially flat surface and may be fixedly
mounted relative to the housing 102 using any number of components
and/or approaches. The image sensor 112 further has a defined
central imaging axis, A, that is normal to the substantially flat
surface. In some embodiments, the imaging axis A is coaxial with a
central axis of the lens assembly 120. The lens assembly 120 may
also be fixedly mounted relative to the housing 102 using any
number of components and/or approaches. In the illustrated
embodiment, the lens assembly 120 is positioned between a front
aperture 114 and the image sensor 112. The front aperture 114
blocks light from objects outside of the field of view which
reduces imaging problems due to stray light from objects other than
the target object. Additionally, the front aperture 114 in
conjunction with a one or more lenses allows for the image to form
correctly on the imaging sensor 112.
[0047] The housing 102 includes an illumination system 150
configured to illuminate a target object of interest for imaging of
the target. The target may be a 1D barcode, 2D barcode, QR code,
UPC code, or another indicia indicative of the object of interest
such as alphanumeric characters or other indicia. The illumination
system 150 may be an adaptive illumination system as described
further herein. The illumination system 150 may adaptively provide
a wide-angle illumination FOV 122a to enable wide-angle imagine of
a close target 124a, or provide a narrow-angle illumination FOV
122b to for imagine of a far-away target 124b.
[0048] FIG. 2 illustrates an embodiment of a scanning station 200
that includes an adaptive illumination system. Goods 102 are moved
across or along a scanning surface 204, are illuminated by an
adaptive illumination source 150, and imaged by an imaging system
110, of an imaging reader 206 to identify the goods 202. In some
embodiments, the scanning station 200 is a point-of-sale (POS)
station, which may have a computer system and an interface, not
shown, for optically scanning goods and identifying the goods and
characteristics of the goods for affecting a transaction. In some
embodiments, the scanning station is part of an inventory delivery
system, where goods are conveyed by the scanning surface or across
the scanning surface to monitor and control delivery of the goods,
for example, shipping goods from a facility or receiving shipped
goods to a facility.
[0049] The scanning surface 204 may be a stationary surface, such
that the goods 202 are manually moved relative to the surface 204.
In embodiments, the scanning surface 204 may move the goods 202 or
be moved by another automated means. In other embodiments, the
scanning surface 204 may be a moving surface, such as by a conveyor
system such as a conveyer belt, pneumatic conveyer, wheel conveyer,
roller conveyer, chain conveyer, flat conveyer, vertical conveyer,
trolley conveyer, or another conveyer. In any case, the goods 202
may be moved continuously relative to the imaging reader 206, such
that the goods 202 are constantly moving through a current working
(or scanning) range of the station 200. For example, the station
may have a wide-angle working range 208a and a narrow FOV 208b
depending on the distance of the good 202, an illumination FOV of
the adaptive illumination system 150, and/or an FOV of the imaging
system 110. In some examples, the goods 202 move in a discretized
manner, where, at least part of the time the goods 202 are
maintained fixed on the surface 204 relative to the imaging reader
206 for a period of time, sufficient to allow one or more images to
be captured of the goods 202.
[0050] The goods 202 may move along different substantially linear
paths 210A, 210B, etc. each path traversing the working ranges 208a
and 208b but at a different distance from the imaging reader 206.
The adaptive illumination system 150 may change the illumination
FOV depending on the distance of the goods 202 from the imaging
reader 206. For example, the imaging system 110 may determine an
imaging focal distance of the good 202 and the adaptive
illumination system 150 may change the illumination FOV depending
on the imaging focal distance. In embodiments, a controller may
control the adaptive illumination system 150 to control the FOV of
the adaptive illumination system 150. The paths 210A, 210B are for
illustration purposes, as the goods 202 may traverse across the
surface 204 at any distance from the imaging reader 206, and,
accordingly, the adaptive illumination system may provide a range
of illumination FOVs for imaging the goods depending on the
distance of the goods 202 from the imaging reader 206.
[0051] FIG. 3 illustrates a block connection diagram of system 300
including an imaging reader 206. While in reference herein to the
imaging reader 206 of FIG. 2, the system 300 may be implemented
with the imaging device 100 of FIG. 1. In FIG. 3 the imaging reader
206 may have one or more processors and one or more memories
storing computer executable instructions to perform operations
associated with the systems and methods as described herein. The
imaging reader 206 includes a network input/output (I/O) interface
for connecting the reader to the server 212, an inventory
management system (not shown), and other imaging readers. These
devices may be connected via any suitable communication means,
including wired and/or wireless connectivity components that
implement one or more communication protocol standards like, for
example, TCP/IP, WiFi (802.11b), Bluetooth, Ethernet, or any other
suitable communication protocols or standards. The imaging reader
106 further includes a display for providing information such as
visual indicators, instructions, data, and images to a user.
[0052] In some embodiments, the server 212 (and/or other connected
devices) may be located in the same scanning station 200. In other
embodiments, server 212 (and/or other connected devices) may be
located at a remote location, such as on a cloud-platform or other
remote location. In still other embodiments, server 212 (and/or
other connected devices) may be formed of a combination of local
and cloud-based computers.
[0053] Server 212 is configured to execute computer instructions to
perform operations associated with the systems and methods as
described herein. The server 212 may implement enterprise service
software that may include, for example, RESTful (representational
state transfer) API services, message queuing service, and event
services that may be provided by various platforms or
specifications, such as the J2EE specification implemented by any
one of the Oracle WebLogic Server platform, the JBoss platform, or
the IBM WebSphere platform, etc. Other technologies or platforms,
such as Ruby on Rails, Microsoft .NET, or similar may also be
used.
[0054] In the illustrated example, the imaging reader 206 includes
an adaptive illumination system 150, which may include a visible
light source (e.g., a light emitting diode (LED) emitting at 640
nm) or an infrared light source (e.g., emitting at or about 700 nm,
850 nm, or 940 nm, for example), with the adaptive illumination
system 150 capable of generating an illumination beam that
illuminates the a working range 208a or 208b for imaging over an
entire working distance of that working range 208a or 208b. That
is, the adaptive illumination system 150 is configured to
illuminate over at least each of the entire working ranges 208a and
208b. In embodiments, the adaptive illumination system 150 may be
capable of illuminating a plurality of working ranges with each
having a corresponding FOV and working distance from the imaging
reader 206. The illumination intensity of the adaptable
illumination system 150 and the sensitivity of an imaging reader
can determine the further and closest distances (defining the
distance of the working range, also termed the scanning range), and
the working ranges in respect to illumination FOV, over which a
good can be scanned, and a barcode on the good can be decoded.
[0055] The adaptive illumination system 150 may be controlled by a
processor and may be a continuous light source, an intermittent
light source, or a signal-controlled light source, such as a light
source trigged by an object detection system coupled (or formed as
part of though not shown) to the imaging reader 206. The adaptable
illumination system may include a light source such as a laser
diode, an LED, a black body radiation source, an infrared light
source, a near-infrared light source, an ultraviolet light source,
a visible light source, an omnidirectional illumination source, or
another illumination source. Additionally, the adaptive
illumination system 150 may include optics for dispersing,
focusing, and/or filtering optical radiation for illumination of
the target object. In embodiments, the adaptive illumination system
150 may be housed inside of the housing 102 of FIG. 1 or may attach
to the external surfaces of the housing 102. In embodiments, the
adaptive imaging system 150 may be housed in the imaging reader 206
of FIG. 3 or may attach to the external surface of the imaging
reader 206. In embodiments, the adaptive imaging system 150 may be
a separate device or component from the housing 102 and/or imaging
reader 106, with the adaptive illumination system 150 configured to
illuminate the target object for capturing an image by the imagine
device 100 or the imaging reader 106.
[0056] The imaging reader 106 further includes the imaging system
110 having an imaging sensor 306 positioned to capture images of an
illuminated target, such as the goods 102 or another object of
interest (001), within a working range 208a or 208b of the imagine
reader 206. In some embodiments, the imaging sensor 306 is formed
of one or more CMOS imaging arrays. In some embodiments the imaging
sensor may be a charge coupled device or another solid-state
device. The imaging sensor 306 may be a one-megapixel sensor with
pixels of approximately three microns in size. In embodiments, the
imaging sensor includes 3-millimeter pixels, having a total of
about 2 megapixels, resulting in an overall imaging sensor width
and length of 3 microns in each dimension. In embodiments, the
imaging sensor 306 may be a variable focus imaging sensor such as
an auto-focus camera capable of changing imaging focal planes for
imaging objects at different distances from the imaging reader
206.
[0057] The imaging reader may include one or more windows 310 for
allowing illumination from the adaptive illumination system 150 to
exit the imaging reader 206, and for light from the 001 to reach
the image sensor 306. In embodiments, the adaptive illumination
system 150 may be external to the imaging reader 206 and the
external illumination system may include a window for transmitting
the illumination, or the external illumination system may emit the
illumination into free space without the use of a window. In
embodiments, the adaptive illumination system 150 may provide
illumination to an 001 through optical filters, a window, spatial
filters, an aperture, or another structure to provide the
illumination of the OOI.
[0058] A focus controller 314 is coupled to the controls the
imaging sensor 306 and any variable focus optics (e.g., a
deformable lens, a liquid lens, a translatable lens, a translatable
grating, or other variable focus optical elements) to define one or
more discrete imaging planes for the imaging sensor 306. In
embodiments, the imaging system 110 may include a focusing lens
drive, a shift lens drive, a zoom lens drive, an aperture drive,
angular velocity drive, voice coil motor drive, and/or other drive
units for controlling the focal distance of the imaging system 110,
which may further include multiple lens, lens stages, etc. In
embodiments, once a focal plane for imaging an 001 is established
by the image sensor 306, the focus controller 314, and/or a
processor in communication with the image sensor 306 and focus
controller 314, information indicative of the focal distance may be
provided to the illumination controller 55. The illumination
controller 155 may process the information indicative of the focal
distance to determine a desired FOV and illumination distance
(i.e., illumination intensity output) of the adaptive illumination
system 150. The illumination controller 155 may then control the
adaptive illumination system 150 to cause the adaptive illumination
system 150 to provide illumination according to the determined FOV
an illumination distance. In some embodiments, the adaptive
illumination system 150 includes a movable multiple lens array
coupled to a voice coil actuator motor that is controllably
adjusted by the illumination controller 155 to change the
illumination FOV.
[0059] In embodiments, the memory may store information regarding
the focal distances of OOIs such as the good 202 and the
illumination controller 155 may retrieve the information from the
memory to determine a desired illumination FOV and illumination
intensity, or a plurality of potential illumination FOVs and
illumination intensities. The illumination controller 155 may then
determine, based on information from the focus controller 314 one
of the plurality of illumination FOVS and illumination intensities,
and control the adaptive illumination system 150 to provide
illumination at the determined illumination FOV and illumination
intensity. Further, the illumination controller may control the
adaptive illumination system 150 to provide illumination according
to various FOVs and illumination intensities to determine desired
illumination parameters for a given OOI, or to provide the imaging
system 110 with various illuminations for capturing a plurality of
images on an OOI. A preferred illumination may then be determined
by the imaging system 110, or a processor in communications with
the imaging system 110, and the illumination controller 155 may be
provided with the determined desired illumination.
[0060] FIGS. 4A and 4B illustrate an optical assembly 400 of the
adaptive illumination system 150 of FIGS. 1 and 2 in accordance
with some embodiments. FIG. 4A is a cross-sectional side view of
the optical assembly 400, while FIG. 4B is a perspective view of
the optical assembly 400 including ray tracing. Referring now to
FIGS. 4A and 4B, the optical assembly 400 includes an illumination
source 402, a collimating lens 404, a fixed multiple lens array
(MLA) 410, and a movable MLA 414. The optical source 402 provides
illumination along an optical axes A to provide illumination to a
target. In embodiments, the target may be an object of interest
itself, or the target may include indicia indicative of an object
of interest such as a barcode, alphanumeric identifier, or other
indicia. The illumination source 402 provides illumination to the
collimating lens 404. In embodiments, the illumination source 402
may include a laser diode, an LED, a black body radiation source,
an infrared light source, a near-infrared light source, an
ultraviolet light source, a visible light source, an
omnidirectional illumination source, or another light source. The
collimating lens 404 is disposed along the optical axis A
configured to receive the illumination in the form of light from
the illumination source 402. The collimating lens 404 has a first
surface 404a configured to receive the light from the illumination
source 402, and a second surface 404b configured to provide the
light to the movable MLA 414. The first surface 404a of the
collimating lens 404 is a planar surface and the second surface
404b of the collimating lens is a convex surface. In embodiments,
the collimating lens may be an acrylic, polycarbonate, Zeonex, a
glass material such as BK1, H-ZLAF68, H-LAK53B or another glass,
plastic, or optical material capable of transmitting light through
it. In embodiments, both the first and second surfaces 404a and
404b are convex surfaces and each of the first and second surfaces
404a and 404b may be spherical or aspherical. In embodiments, the
collimating lens 404 has an overall positive optical power with an
index of refraction from 1.4 to 2.0 and Abbe value from 20 to 70.
The collimating lens 404 is configured to collimate the light, or
to approximately collimate the light, to provide the collimated
light to the fixed MLA 410. In embodiments, the collimating lens
404 collimates the light to have a divergence of less than
1.degree., less than 2.degree., less than 5.degree., less than
8.degree., less than 10.degree., less than 15.degree., or less than
20.degree..
[0061] The fixed MLA 410 is disposed along the optical axis A
configured to receive the light from the collimating lens 404. The
fixed MLA 410 has a first surface 410a disposed along the optical
axis A configured to receive the light from the collimating lens
404 and a second surface 410b disposed along the optical axis A
configured to provide the light to the movable MLA 414. The first
surface 410a of the fixed MLA 410 is a planar surface and the
second surface 410b of the fixed MLA 410b is a surface having a
plurality of lens cells that make up the multiple lens array (MLA)
of the fixed MLA 410. In embodiments, the plurality of lens cells
is a plurality of convex lens cells. Each lens cell of the
plurality of convex lens cells may have a size of approximately
0.6.+-.0.05 by 0.7.+-.0.05 millimeters, 0.5.+-.0.05 by 0.6.+-.0.05
millimeters, 0.4.+-.0.05 millimeters by 0.5.+-.0.05 millimeters,
0.3.+-.0.05 millimeters by 0.4.+-.0.05 millimeters, 0.2.+-.0.05 by
0.3.+-.0.05 millimeters, 0.1.+-.0.05 by 0.2.+-.0.05 millimeters. In
embodiments, lens cells of the plurality of lens cells may have
equal dimensions, for example, each lens cell may have a size of
0.1.+-.0.05 by 0.1.+-.0.05 millimeters, 0.2.+-.0.05 by 0.2.+-.0.05
millimeters, 0.3.+-.0.05 by 0.3.+-.0.05 millimeters, or dimensions
greater than 0.3 millimeters. In embodiments, the width and height
of each of the lens cells of the plurality of lens cells may
independently be between 0.2 millimeters to 1.2 millimeters. In
embodiments, the fixed MLA 410 may be a plastic material such as
Zeonex, Acrylic, Polycarbonate, K26R, E48R or another plastic
material. In embodiments, the fixed MLA 410 may be a glass material
or other optical material able to transmit light. In embodiments,
the fixed MLA 410 has an index of refraction of 1.45 to 1.8 and an
Abbe value of 25 to 65. In embodiments, each of the lenses of the
plurality of lens cells have an effective focal distance of
approximately 0.2.+-.0.05 millimeters to 1.0.+-.0.05 millimeters.
In embodiments, the lens surface of each of the lenses of the
plurality of lenses may be spherical, aspherical, toroidal, or free
form. In a preferred embodiment, the fixed MLA 410 has a positive
optical power. In embodiments, the lens surface of each of the
lenses of the plurality of lenses may be a toroidal shape with X
and Y radii of 0.2 to 2.0 millimeters. As described herein, X and Y
axis may be considered a horizontal and vertical axis, or any two
orthogonal dimensional axes in a coordinate space. In embodiments,
the thickness of the fixed MLA 410 is between 0.2 millimeters and
1.2 millimeter. In embodiments, the first and second surfaces 410a
and 410b of the fixed MLA 410 may be a same material, or the first
surface 410a of the fixed MLA 410 may be a first material and the
second surface 410b of the fixed MLA 410 may be a second material
that is different than the first material. In embodiments, the
first surface 410a of the fixed MLA 410 may include a plurality of
lens cell and the second surface 410b of the fixed MLA 410 may be a
planar surface. In embodiments, both the first surface 410a and the
second surface 410b of the fixed MLA 410 may be a planar surface,
or both may be a surface having a plurality of lens cells. In
embodiments, either of the first and second surfaces 410a and 410b
of the fixed MLA 410 may each independently be a concave or convex
surface.
[0062] The movable MLA 414 is disposed along the optical axis A
configured to receive the light from the fixed MLA 410. The movable
MLA 414 has a first surface 414a disposed along the optical axis
configured to receive the light from the fixed MLA 410 and a second
surface 414b disposed along the optical axis A configured to
provide the light to the target. The first surface 414a of the
movable MLA 414 is a surface having a plurality of lens cells that
make up the multiple lens array of the movable MLA 410, and the
second surface 414b of the movable MLA 414b is a planar surface. In
embodiments, the plurality of lens cells is a plurality of convex
lens cells. Each lens cell of the plurality of convex lens cells
may have a size of approximately 0.6.+-.0.05 by 0.7.+-.0.05
millimeters, 0.5.+-.0.05 by 0.6.+-.0.05 millimeters, 0.4.+-.0.05
millimeters by 0.5.+-.0.05 millimeters, 0.3.+-.0.05 millimeters by
0.4.+-.0.05 millimeters, 0.2.+-.0.05 by 0.3.+-.0.05 millimeters,
0.1.+-.0.05 by 0.2.+-.0.05 millimeters. In embodiments, lens cells
of the plurality of lens cells may have equal dimensions, for
example, each lens cell may have a size of 0.1.+-.0.05 by
0.1.+-.0.05 millimeters, 0.2.+-.0.05 by 0.2.+-.0.05 millimeters,
0.3.+-.0.05 by 0.3.+-.0.05 millimeters, or dimensions greater than
0.3 millimeters. In embodiments, the width and height of each of
the lens cells of the plurality of lens cells may independently be
between 0.2 millimeters to 1.2 millimeters. In embodiments, the
movable MLA 414 may be a plastic material such as Zeonex, Acrylic,
Polycarbonate, K26R, E48R or another plastic material. In
embodiments, the movable MLA 414 may be a glass material or other
optical material able to transmit light. In embodiments, the
movable MLA 414 has an index of refraction of 1.45 to 1.8 and an
Abbe value of 25 to 65. In embodiments, each of the lenses of the
plurality of lens cells have an effective focal distance of
approximately 0.2.+-.0.05 millimeters to 1.0.+-.0.05 millimeters.
In embodiments, the lens surface of each of the lenses of the
plurality of lenses may be spherical, aspherical, toroidal, or free
form. In a preferred embodiment, the movable MLA 414 has a positive
optical power. In embodiments, the lens surface of each of the
lenses of the plurality of lenses may be a toroidal shape with X
and Y radii of 0.2 to 2.0 millimeters. In embodiments, the
thickness of the fixed MLA 410 is between 0.2 millimeters and 1.2
millimeter. In embodiments, the first and second surfaces 414a and
414b of the movable MLA 414 may be a same material, or the first
surface 414a of the movable MLA 414 may be a first material and the
second surface 414b of the movable MLA 414 may be a second material
that is different from the first material. In embodiments, the
first surface 414a of the movable MLA 414 may be a planar surface
and the second surface 414b of the movable MLA 414 may include a
plurality of lens cells. In embodiments, both the first surface
414a and the second surface 414b of the movable MLA 414 may be a
planar surface, or both may be a surface having a plurality of lens
cells. In embodiments, either of the first and second surfaces 414a
and 414b of the movable MLA 414 may each independently be a concave
or convex surface. In preferred embodiments, the overall length of
the optical assembly 400 along the optical axis A from the
illumination source 402 to the movable MLA 414 is less than 11 mm.
In embodiments, the length of the optical assembly 400 may be 25
millimeters or less.
[0063] In embodiments, a motor 416 is coupled to the movable MLA
414 configured to move the movable MLA 414 closer to change the
position of the movable MLA 414 to adjust the illumination FOV of
the optical assembly 400 of the adaptable illumination system 150.
In embodiments, the motor 416 may be an actuator, a voice coil
motor, a piezoelectric device, a microelectromechanical systems
(MEMS) motor, or another compact motor. In embodiments, the motor
416 may be configured to move the movable MLA 414 a travel distance
of between 0.2 millimeters and 3 millimeters. At a given separation
distance 420 of the movable MLA 414 from the fixed MLA 410 the
adaptable illumination system 150 exhibits a first illumination
FOV, and at a different distance 420, the illumination system
exhibits a different illumination FOV. For example, as the distance
420 between the movable MLA 414 and the fixed MLA 410 increased the
illumination FOV narrows.
[0064] FIGS. 5A, 6A, and 7A are cross-sectional side views of the
optical assembly of FIG. 4A having a distance 420 of 0 millimeters,
0.5 millimeters, and 1 millimeter respectively. The distance 420 is
measured as a distance of motion of the motor 416, which may be
described herein as the motor position distance. A distance 420 of
0 millimeters as described here corresponds to a separation of 0.2
millimeters between the second surface 410b of the fixed MLA 410
and the first surface 414a of the movable MLA 414. Therefore,
distances 420 of 0.5 millimeters and 1 millimeters correspond to
separations of 0.7 millimeters and 1.2 millimeters, respectively,
between the second surface 410b of the fixed MLA 410 and the first
surface 414a of the movable MLA 414. In embodiments, the motor 416
may be configured to allow the movable MLA 414 to physically come
into contact with the fixed MLA 410 and therefore the separation of
the two MLA's would be 0 millimeters. In embodiments, the motor 416
may be configured to move the movable MLA 414 to any range of
distances 420 to provide a desired illumination FOV for
illuminating the target.
[0065] FIGS. 5B, 6B, and 7B are images of the illumination field of
the optical configurations of the optical assemblies 400 of FIGS.
5A, 6A, and 7A respectively, at a distance of 200 millimeters from
the collimating lens along the optical axis, A. FIGS. 5C, 6C, and
7C are the illumination full field angles in polar coordinates for
the optical configurations of the optical assemblies 400 shown in
FIGS. 5A, 6A, and 7A respectively. The light intensity shown in
FIGS. 5C, 6C, and 7C is normalized to one. The polar illumination
plots illustrate the far field light radiant intensity
distribution, which represents how much light propagates within a
particular angle segment. The Y-axis has a maximum of 1.0 which
represents the normalized light radiant intensity within an angle
segment. The FOVs represented in FIGS. 5C, 6C, and 7C were defined
as the 0.5 (i.e., 50%) light intensity drop off of the
illumination.
[0066] As shown by the FIGS. 5A-5C, 6A-6C, and 7A-7C, the
illumination FOV decreases with increased distance 420 between the
fixed MLA 410 and the movable MLA 414. The illumination FOV is
tuned from approximately 42 degrees in FIG. 5C, to approximately 16
degrees in FIG. 7C. Therefore, the optical configuration of FIG. 7A
allows for illumination of a target at further distances than
either of the optical configurations of FIGS. 5A or 6A, and the
configuration of FIG. 5A may provide for more efficient imaging or
reading of a target that is closer to the adaptive illumination
system 150. In embodiments, the FOV may be tuned from 10 to 20
degrees, 20 to 40 degrees, 30 to 60 degrees, to less than 50
degrees, to greater than 60 degrees, or to any range of values
between 4 and 80 degrees.
[0067] FIG. 8 illustrates an optical assembly 800 of the adaptive
illumination system 150 of FIGS. 1 and 2 in accordance with some
embodiments. FIG. 8 is a cross-sectional side view of the optical
assembly 800. Referring now to FIG. 8 optical assembly 800 includes
an illumination source 802, a collimating lens 804, a first fixed
MLA 806, a movable MLA 810, and a second fixed MLA 814. The
illumination source 802 provides illumination along an optical axes
B to provide illumination to a target. In embodiments, the target
may be an object of interest itself, or the target may include
indicia indicative of an object of interest such as a barcode,
alphanumeric identifier, or other indicia. The illumination source
802 provides illumination to the collimating lens 804. In
embodiments, the illumination source may include a laser diode, an
LED, a black body radiation source, an infrared light source, a
near-infrared light source, an ultraviolet light source, a visible
light source, an omnidirectional illumination source, or another
light source. The collimating lens 804 is disposed along the
optical axis B configured to receive the illumination in the form
of light from the illumination source 802. The collimating lens 804
has a first surface 804a configured to receive the light from the
illumination source 802, and a second surface 804b configured to
provide the light to the first fixed MLA 806. The first surface
804a of the collimating lens 804 is a planar surface and the second
surface 804b of the collimating lens 804 is a convex surface. In
embodiments, the collimating lens 804 may be acrylic,
polycarbonate, Zeonex, a glass material such as BK1, H-ZLAF68,
H-LAK536 or another glass, plastic, or optical material capable of
transmitting light through it. In embodiments, both the first and
second surfaces 804a and 804b are convex surfaces and each of the
first and second surfaces 804a and 804b may be spherical or
aspherical. In embodiments, the collimating lens 804 has an overall
positive optical power with an index of refraction from 1.4 to 2.0
and Abbe value from 20 to 70. The collimating lens 804 is
configured to collimate the light, or to approximately collimate
the light, to provide the collimated light to the first fixed MLA
806. In embodiments, the collimating lens 804 collimates the light
to have a divergence of less than 1.degree., less than 2.degree.,
less than 5.degree., less than 8.degree., less than 10.degree., or
less than 15.degree..
[0068] The first fixed MLA 806 is disposed along the optical axis B
configured to receive the light from the collimating lens 802. The
first fixed MLA 806 has a first surface 806a disposed along the
optical axis B configured to receive the light from the collimating
lens 804 and a second surface 810b disposed along the optical axis
B configured to provide the light to the movable MLA 810. The first
surface 806a of the first fixed MLA 806 is a planar surface and the
second surface 806b of the first fixed MLA 806 is a surface having
a plurality of lens cells that make up the multiple lens array
(MLA) of the first fixed MLA 806. In embodiments, the plurality of
lens cells is a plurality of convex lens cells. Each lens cell of
the plurality of convex lens cells may have a size of approximately
0.6.+-.0.05 by 0.7.+-.0.05 millimeters, 0.5.+-.0.05 by 0.6.+-.0.05
millimeters, 0.4.+-.0.05 millimeters by 0.5.+-.0.05 millimeters,
0.3.+-.0.05 millimeters by 0.4.+-.0.05 millimeters, 0.2.+-.0.05 by
0.3.+-.0.05 millimeters, 0.1.+-.0.05 by 0.2.+-.0.05 millimeters. In
embodiments, lens cells of the plurality of lens cells may have
equal dimensions, for example, each lens cell may have a size of
0.1.+-.0.05 by 0.1.+-.0.05 millimeters, 0.2.+-.0.05 by 0.2.+-.0.05
millimeters, 0.3.+-.0.05 by 0.3.+-.0.05 millimeters, or dimensions
greater than 0.3 millimeters. In embodiments, the width and height
of each of the lens cells of the plurality of lens cells may
independently be between 0.2 millimeters to 1.2 millimeters. In
embodiments, the first fixed MLA 806 may be a plastic material such
as Zeonex, Acrylic, Polycarbonate, K26R, E48R or another plastic
material. In embodiments, the first fixed MLA 806 may be a glass
material or other optical material able to transmit light. In
embodiments, the first fixed MLA 806 has an index of refraction
from 1.45 to 1.8 and an Abbe value of 25 to 65. In embodiments,
each of the lenses of the plurality of lens cells have an effective
focal distance of approximately 0.2.+-.0.05 millimeters to
1.0.+-.0.05 millimeters. In embodiments, the lens surface of each
of the lenses of the plurality of lenses may be spherical,
aspherical, toroidal, or free form. In a preferred embodiment, the
first fixed MLA 806 has a positive optical power. In embodiments,
the lens surface of each of the lenses of the plurality of lenses
may be a toroidal shape with X and Y radii of 0.2 to 2.0
millimeters. In embodiments, the thickness of the first fixed MLA
806 is between 0.2 millimeters and 1.2 millimeter.
[0069] In embodiments, the first and second surfaces 806a and 806b
of the first fixed MLA 806 may be a same material, or the first
surface 806a of the first fixed MLA 806 may be a first material and
the second surface 806b of the first fixed MLA 806 may be a second
material that is different than the first material. In embodiments,
the first surface 80a of the first fixed MLA 806 may include a
plurality of lens cells and the second surface 806b of the first
fixed MLA 806 may be a planar surface. In embodiments, both the
first surface 806a and the second surface 806b of the first fixed
MLA 806 may be a planar surface, or both the first surface 806a and
the second surface 806b may be a surface having a plurality of lens
cells.
[0070] The movable MLA 810 is disposed along the optical axis B
configured to receive the light from the first fixed MLA 806. The
movable MLA 810 has a first surface 810a disposed along the optical
axis B configured to receive the light from the first fixed MLA 806
and a second surface 810b disposed along the optical axis B
configured to provide the light to the second fixed MLA 814. The
first surface 810a of the movable MLA 810 is a surface having a
plurality of lens cells, and the second surface 810b of the movable
MLA 810 is a surface having a plurality of lens cells. In
embodiments, plurality of lens cells of the first surface 810a is a
plurality of convex lens cells, and the plurality of lens cells of
the second surface 810b is a plurality of convex lens cells. Each
lens cell of the plurality of lens cells of the first and second
surfaces 810a and 810b may have a size of approximately 0.6.+-.0.05
by 0.7.+-.0.05 millimeters, 0.5.+-.0.05 by 0.6.+-.0.05 millimeters,
0.4.+-.0.05 millimeters by 0.5.+-.0.05 millimeters, 0.3.+-.0.05
millimeters by 0.4.+-.0.05 millimeters, 0.2.+-.0.05 by 0.3.+-.0.05
millimeters, 0.1.+-.0.05 by 0.2.+-.0.05 millimeters. In
embodiments, lens cells of the pluralities of lens cells of the
first and second surfaces 810a and 810b may have equal dimensions,
for example, each lens cell may have a size of 0.1.+-.0.05 by
0.1.+-.0.05 millimeters, 0.2.+-.0.05 by 0.2.+-.0.05 millimeters,
0.3.+-.0.05 by 0.3.+-.0.05 millimeters, or dimensions greater than
0.3 millimeters. In embodiments, the lens cells of the plurality of
lens cells of the first surface 810a may have same dimensions as
the lens cells of the plurality of lens cells of the second surface
810b, or the plurality of lens cells of the first surface 810a may
have different dimensions than the lens cells of the plurality of
lens cells of the second surface 810b. In embodiments, the width
and height of each of the lens cells of the plurality of lens cells
of the first and/or second surfaces 810a and 810b may independently
be between 0.2 millimeters to 1.2 millimeters. In embodiments, the
movable MLA 810 may be a plastic material such as Zeonex, Acrylic,
Polycarbonate, K26R, E48R or another plastic material. In
embodiments, the movable MLA 810 may be a glass material or other
optical material able to transmit light. In embodiments, the
movable MLA 810 has an index of refraction from 1.45 to 1.8 and an
Abbe value of 25 to 65. In embodiments, each of the lenses of the
plurality of lens cells of the first and/or second surfaces 810a
and 810b have an effective focal distance of approximately
0.2.+-.0.05 millimeters to 1.0.+-.0.05 millimeters. In embodiments,
the lens surface of each of the lenses of the plurality of lenses
may be spherical, aspherical, toroidal, or free form. In a
preferred embodiment, the movable MLA 810 has a positive optical
power. In embodiments, the lens surface of each of the lenses of
the plurality of lenses may be a toroidal shape with X and Y radii
of 0.2 to 2.0 millimeters. In embodiments, the thickness of the
movable MLA 810 is between 0.2 millimeters and 1.2 millimeter. In
embodiments, the first and second surfaces 810a and 810b of the
movable MLA 810 may be a same material, or the first surface 810a
of the movable MLA 810 may be a first material and the second
surface 810b of the movable MLA 810 may be a second material that
is different from the first material. In embodiments, the first
surface 810a of the movable MLA 810 may be a planar surface and the
second surface 810b of the movable MLA 810 may include a plurality
of lens cells, or the first surface 810a of the movable MLA 810 may
be a surface having a plurality of lens cells and the second
surface 810b of the movable MLA 810 may be a planar surface. In
embodiments, both the first surface 810a and the second surface
810b of the movable MLA 810 may be a planar surface.
[0071] In embodiments, a motor 816 is coupled to the movable MLA
810 configured to move the movable MLA 810 along the optical axis B
between the first fixed MLA 806 and the second fixed MLA 814 to
adjust the illumination FOV of the optical assembly 800 of the
adaptable illumination system 150. In embodiments, the motor 416
may be an actuator, a voice coil motor, a piezoelectric device, a
microelectromechanical systems (MEMS) motor, or another compact
motor. In embodiments, the motor 416 may be configured to move the
movable MLA 414 a travel distance of between 0.2 millimeters and 3
millimeters. In embodiments, the motor 816 may be configured to
move the movable MLA 810 a travel distance of between 0.2
millimeters and 1 millimeter. At a given separation distance 820
between the second surface 806b of the first fixed MLA 806 and the
first surface 810a of the movable MLA 810, the adaptable
illumination system 150 exhibits a first illumination FOV, and at a
different distance 820, the illumination system 150 exhibits a
different illumination FOV. For example, as the distance 820
between the movable MLA 810 and the first fixed MLA 806 is
increased the illumination FOV narrows.
[0072] The second fixed MLA 814 is disposed along the optical axis
B configured to receive the light from the movable MLA 810. The
second fixed MLA 814 has a first surface 814a disposed along the
optical axis B configured to receive the light from the movable MLA
810 and a second surface 814b disposed along the optical axis B
configured to provide the light to the target. The first surface
814a of the second fixed MLA 814 is a surface having a plurality of
lens cells and the second surface 814b of the second fixed MLA 814
is a planar surface. In embodiments, the plurality of lens cells is
a plurality of concave lens cells. Each lens cell of the plurality
of concave lens cells may have a size of approximately 0.6.+-.0.05
by 0.7.+-.0.05 millimeters, 0.5.+-.0.05 by 0.6.+-.0.05 millimeters,
0.4.+-.0.05 millimeters by 0.5.+-.0.05 millimeters, 0.3.+-.0.05
millimeters by 0.4.+-.0.05 millimeters, 0.2.+-.0.05 by 0.3.+-.0.05
millimeters, 0.1.+-.0.05 by 0.2.+-.0.05 millimeters. In
embodiments, lens cells of the plurality of lens cells may have
equal dimensions, for example, each lens cell may have a size of
0.1.+-.0.05 by 0.1.+-.0.05 millimeters, 0.2.+-.0.05 by 0.2.+-.0.05
millimeters, 0.3.+-.0.05 by 0.3.+-.0.05 millimeters, or dimensions
greater than 0.3 millimeters. In embodiments, the width and height
of each of the lens cells of the plurality of lens cells may
independently be between 0.2 millimeters to 1.2 millimeters. In
embodiments, the second fixed MLA 814 may be a plastic material
such as Zeonex, Acrylic, Polycarbonate, K26R, E48R or another
plastic material. In embodiments, the second fixed MLA 814 may be a
glass material or other optical material able to transmit light. In
embodiments, the second fixed MLA 814 has an index of refraction
from 1.45 to 1.8 and an Abbe value of 25 to 65. In embodiments,
each of the lenses of the plurality of lens cells have an effective
focal distance of approximately 0.2.+-.0.05 millimeters to
1.0.+-.0.05 millimeters. In embodiments, the lens surface of each
of the lenses of the plurality of lenses may be spherical,
aspherical, toroidal, or free form. In a preferred embodiment, the
second fixed MLA 806 has a negative optical power. In embodiments,
the lens surface of each of the lenses of the plurality of lenses
may be a toroidal shape with X and Y radii of 0.2 to 2.0
millimeters. In embodiments, the thickness of the first fixed MLA
806 is between 0.2 millimeters and 1.2 millimeter.
[0073] In embodiments, the first and second surfaces 814a and 814b
of the second fixed MLA 814 may be a same material, or the first
surface 814a of the second fixed MLA 814 may be a first material
and the second surface 814b of the second fixed MLA 814 may be a
second material that is different than the first material. In
embodiments, the first surface 814a of the second fixed MLA 814 may
be a planar surface and the second surface 814b of the second fixed
MLA 814 may have a plurality of lens cells. In embodiments, both
the first surface 814a and the second surface 814b of the second
fixed MLA 814 may be a planar surface, or both the first surface
814a and the second surface 814b may be a surface having a
plurality of lens cells. In embodiments, the overall length of the
optical assembly 800 along the optical axis B from the illumination
source 802 to the second surface 814b of the second fixed MLA 814
is less than 25 mm. In embodiments, the overall length of the three
MLA elements along the optical axis B from the first surface 806a
of the first fixed MLA 806 to the second surface 814b of the second
fixed MLA 814 may be 3 millimeters, between 1 and 5 millimeters, or
less than 7 millimeters.
[0074] In embodiments, a motor may be physically coupled to the
second fixed MLA 814 to allow the second fixed MLA 814 to translate
and therefore be a second movable MLA. The motor physically coupled
to the second fixed MLA 814 may be configured to move the second
fixed MLA 814 along the optical axis B to change the illumination
FOV of the adaptive illumination system 150. In embodiments, the
motor 416 may be an actuator, a voice coil motor, a piezoelectric
device, a microelectromechanical systems (MEMS) motor, or another
compact motor. In embodiments, the motor 416 may be configured to
move the movable MLA 414 a travel distance of between 0.2
millimeters and 3 millimeters. In embodiments, the motor may be
configured to move the second fixed MLA 814 a travel distance of
between 0.2 millimeters and 1 millimeter
[0075] FIGS. 9A, 10A, and 11A are cross-sectional side views of the
optical assembly 800 of FIG. 8 having a distance 820 of 0
millimeters, 0.25 millimeters, and 0.5 millimeters respectively.
The distance 820 is measured as a distance of motion of the motor
816. A distance 820 of 0 millimeters as described here corresponds
to a separation of 0.2 millimeters between the second surface 806b
of the first fixed MLA 806 and the first surface 810a of the
movable MLA 810. Therefore, distances 820 of 0.25 millimeters and
0.5 millimeters correspond to separations of 0.45 millimeters and
0.7 millimeters, respectively, between the second surface 806b of
the first fixed MLA 806 and the first surface 810a of the movable
MLA 810. In embodiments, the motor 816 may be configured to allow
the movable MLA 810 to physically come into contact with the first
fixed MLA 806 and/or physically in contact with the second fixed
MLA 814. In embodiments, the motor 816 may be configured to move
the movable MLA 810 to any range of distances 820 to provide a
desired illumination FOV for illuminating the target.
[0076] FIGS. 9B, 10B, and 11B are images of the illumination field
of the optical configurations of the optical assemblies 800 of
FIGS. 9A, 10A, and 11A respectively, at a distance of 200
millimeters from the collimating lens along the optical axis, B.
FIGS. 9C, 10C, and 11C are the illumination field angles in polar
coordinates for the optical configurations of the optical
assemblies 800 shown in FIGS. 9A, 10A, and 11A respectively. As
described herein, the illumination field angles shown in FIGS. 9C,
10C, and 11C may be considered to define the illumination FOV. The
light intensity shown in FIGS. 9C, 10C, and 11C is normalized to
one. The polar illumination plots illustrate the far field light
radiant intensity distribution, which represents how much light
propagates within a particular angle segment. The Y-axis has a
maximum of 1.0 which represents the normalized light radiant
intensity within an angle segment. The FOVs represented in FIGS.
9C, 10C, and 11C were defined as the 0.5 (i.e., 50%) light
intensity drop off of the illumination. As shown by the FIGS.
9A-9C, 10A-10C, and 11A-11C, the illumination FOV decreases with
increased distance 820 between the first fixed MLA 806 and the
movable MLA 810. The illumination FOV is tuned from approximately
46 degrees in FIG. 9C, to approximately 24 degrees in FIG. 11C.
Therefore, the optical configuration of FIG. 11A allows for
illumination of a target at further distances than either of the
optical configurations of FIGS. 10A or 9A, and the configuration of
FIG. 9A may provide for more efficient imaging or reading of a
target that is closer to the adaptive illumination system 150. In
embodiments, the illumination FOV may be tuned from 10 to 20
degrees, 20 to 40 degrees, 30 to 60 degrees, to less than 50
degrees, to greater than 60 degrees, or to any range of values
between 4 and 80 degrees.
[0077] The above description of the accompanying drawing of FIG. 3
is one example of the systems and methods described herein.
Alternative implementations of the examples presented include one
or more additional or alternative elements, processes and/or
devices. Additionally or alternatively, one or more of the example
blocks of the diagram may be combined, divided, re-arranged or
omitted. Components represented by the blocks of the diagram are
implemented by hardware, software, firmware, and/or any combination
of hardware, software and/or firmware. In some examples, at least
one of the components represented by the blocks is implemented by a
logic circuit. As used herein, the term "logic circuit" is
expressly defined as a physical device including at least one
hardware component configured (e.g., via operation in accordance
with a predetermined configuration and/or via execution of stored
machine-readable instructions) to control one or more machines
and/or perform operations of one or more machines. Examples of a
logic circuit include one or more processors, one or more
coprocessors, one or more microprocessors, one or more controllers,
one or more digital signal processors (DSPs), one or more
application specific integrated circuits (ASICs), one or more field
programmable gate arrays (FPGAs), one or more microcontroller units
(MCUs), one or more hardware accelerators, one or more
special-purpose computer chips, and one or more system-on-a-chip
(SoC) devices. Some example logic circuits, such as ASICs or FPGAs,
are specifically configured hardware for performing operations
(e.g., one or more of the operations described herein and
represented by the flowcharts of this disclosure, if such are
present). Some example logic circuits are hardware that executes
machine-readable instructions to perform operations (e.g., one or
more of the operations described herein and represented by the
flowcharts of this disclosure, if such are present). Some example
logic circuits include a combination of specifically configured
hardware and hardware that executes machine-readable instructions.
The above description refers to various operations described herein
and flowcharts that may be appended hereto to illustrate the flow
of those operations. Any such flowcharts are representative of
example methods disclosed herein. In some examples, the methods
represented by the flowcharts implement the apparatus represented
by the block diagrams. Alternative implementations of example
methods disclosed herein may include additional or alternative
operations. Further, operations of alternative implementations of
the methods disclosed herein may combined, divided, re-arranged or
omitted. In some examples, the operations described herein are
implemented by machine-readable instructions (e.g., software and/or
firmware) stored on a medium (e.g., a tangible machine-readable
medium) for execution by one or more logic circuits (e.g.,
processor(s)). In some examples, the operations described herein
are implemented by one or more configurations of one or more
specifically designed logic circuits (e.g., ASIC(s)). In some
examples the operations described herein are implemented by a
combination of specifically designed logic circuit(s) and
machine-readable instructions stored on a medium (e.g., a tangible
machine-readable medium) for execution by logic circuit(s).
[0078] As used herein, each of the terms "tangible machine-readable
medium," "non-transitory machine-readable medium" and
"machine-readable storage device" is expressly defined as a storage
medium (e.g., a platter of a hard disk drive, a digital versatile
disc, a compact disc, flash memory, read-only memory, random-access
memory, etc.) on which machine-readable instructions (e.g., program
code in the form of, for example, software and/or firmware) are
stored for any suitable duration of time (e.g., permanently, for an
extended period of time (e.g., while a program associated with the
machine-readable instructions is executing), and/or a short period
of time (e.g., while the machine-readable instructions are cached
and/or during a buffering process)). Further, as used herein, each
of the terms "tangible machine-readable medium," "non-transitory
machine-readable medium" and "machine-readable storage device" is
expressly defined to exclude propagating signals. That is, as used
in any claim of this patent, none of the terms "tangible
machine-readable medium," "non-transitory machine-readable medium,"
and "machine-readable storage device" can be read to be implemented
by a propagating signal.
[0079] In the foregoing specification, specific embodiments have
been described. However, one of ordinary skill in the art
appreciates that various modifications and changes can be made
without departing from the scope of the invention as set forth in
the claims below. Accordingly, the specification and figures are to
be regarded in an illustrative rather than a restrictive sense, and
all such modifications are intended to be included within the scope
of present teachings. Additionally, the described
embodiments/examples/implementations should not be interpreted as
mutually exclusive, and should instead be understood as potentially
combinable if such combinations are permissive in any way. In other
words, any feature disclosed in any of the aforementioned
embodiments/examples/implementations may be included in any of the
other aforementioned embodiments/examples/implementations.
[0080] The benefits, advantages, solutions to problems, and any
element(s) that may cause any benefit, advantage, or solution to
occur or become more pronounced are not to be construed as a
critical, required, or essential features or elements of any or all
the claims. The claimed invention is defined solely by the appended
claims including any amendments made during the pendency of this
application and all equivalents of those claims as issued.
[0081] Moreover in this document, relational terms such as first
and second, top and bottom, and the like may be used solely to
distinguish one entity or action from another entity or action
without necessarily requiring or implying any actual such
relationship or order between such entities or actions. The terms
"comprises," "comprising," "has", "having," "includes",
"including," "contains", "containing" or any other variation
thereof, are intended to cover a non-exclusive inclusion, such that
a process, method, article, or apparatus that comprises, has,
includes, contains a list of elements does not include only those
elements but may include other elements not expressly listed or
inherent to such process, method, article, or apparatus. An element
proceeded by "comprises . . . a", "has . . . a", "includes . . .
a", "contains . . . a" does not, without more constraints, preclude
the existence of additional identical elements in the process,
method, article, or apparatus that comprises, has, includes,
contains the element. The terms "a" and "an" are defined as one or
more unless explicitly stated otherwise herein. The terms
"substantially", "essentially", "approximately", "about" or any
other version thereof, are defined as being close to as understood
by one of ordinary skill in the art, and in one non-limiting
embodiment the term is defined to be within 10%, in another
embodiment within 5%, in another embodiment within 1% and in
another embodiment within 0.5%. The term "coupled" as used herein
is defined as connected, although not necessarily directly and not
necessarily mechanically. A device or structure that is
"configured" in a certain way is configured in at least that way,
but may also be configured in ways that are not listed.
[0082] The Abstract of the Disclosure is provided to allow the
reader to quickly ascertain the nature of the technical disclosure.
It is submitted with the understanding that it will not be used to
interpret or limit the scope or meaning of the claims. In addition,
in the foregoing Detailed Description, it can be seen that various
features are grouped together in various embodiments for the
purpose of streamlining the disclosure. This method of disclosure
is not to be interpreted as reflecting an intention that the
claimed embodiments require more features than are expressly
recited in each claim. Rather, as the following claims reflect,
inventive subject matter may lie in less than all features of a
single disclosed embodiment. Thus, the following claims are hereby
incorporated into the Detailed Description, with each claim
standing on its own as a separately claimed subject matter.
* * * * *