U.S. patent application number 14/157156 was filed with the patent office on 2014-05-15 for refractive-diffractive multifocal lens.
This patent application is currently assigned to PixelOptics, Inc. (Estate of). The applicant listed for this patent is PixelOptics, Inc. (Estate of). Invention is credited to Ronald D. Blum, Roger Clarke, Joshua N. Haddock, Venkatramani S. Iyer, William Kokonaski.
Application Number | 20140132916 14/157156 |
Document ID | / |
Family ID | 40765768 |
Filed Date | 2014-05-15 |
United States Patent
Application |
20140132916 |
Kind Code |
A1 |
Iyer; Venkatramani S. ; et
al. |
May 15, 2014 |
Refractive-Diffractive Multifocal Lens
Abstract
Aspects of the present invention provide multifocal lenses
having one or more multifocal inserts comprising one or more
diffractive regions. A diffractive region of a multifocal insert of
the present invention can provide a constant optical power or can
provide a progression of optical power, or any combination thereof.
A multifocal insert of the present invention can be fabricated from
any type of material and can be inserted into any type of bulk lens
material. A diffractive region of a multifocal insert of the
present invention can be positioned to be in optical communication
with one or more optical regions of a host lens to provide a
combined desired optical power in one or more vision zones. Index
matching layers of the preset invention can be used to reduce
reflection losses at interfaces of the host lens and multifocal
insert.
Inventors: |
Iyer; Venkatramani S.;
(Roanoke, VA) ; Kokonaski; William; (Gig Harbor,
WA) ; Haddock; Joshua N.; (Roanoke, VA) ;
Clarke; Roger; (Cambridge, GB) ; Blum; Ronald D.;
(Roanoke, VA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
PixelOptics, Inc. (Estate of) |
Wilmington |
DE |
US |
|
|
Assignee: |
PixelOptics, Inc. (Estate
of)
Wilmington
DE
|
Family ID: |
40765768 |
Appl. No.: |
14/157156 |
Filed: |
January 16, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13487572 |
Jun 4, 2012 |
8662665 |
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14157156 |
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13005876 |
Jan 13, 2011 |
8197063 |
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13487572 |
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12270116 |
Nov 13, 2008 |
7883207 |
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13005876 |
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12059908 |
Mar 31, 2008 |
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12270116 |
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11964030 |
Dec 25, 2007 |
7883206 |
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12059908 |
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12238932 |
Sep 26, 2008 |
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12270116 |
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11964030 |
Dec 25, 2007 |
7883206 |
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12238932 |
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11964030 |
Dec 25, 2007 |
7883206 |
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11964030 |
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61030789 |
Feb 22, 2008 |
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61038811 |
Mar 24, 2008 |
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61013822 |
Dec 14, 2007 |
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60970024 |
Sep 5, 2007 |
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60956813 |
Aug 20, 2007 |
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60935573 |
Aug 20, 2007 |
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60935492 |
Aug 16, 2007 |
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60935226 |
Aug 1, 2007 |
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60924975 |
Jun 7, 2007 |
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60907367 |
Mar 29, 2007 |
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60978776 |
Oct 10, 2007 |
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60960606 |
Oct 5, 2007 |
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60960607 |
Oct 5, 2007 |
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60970024 |
Sep 5, 2007 |
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60956813 |
Aug 20, 2007 |
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60935573 |
Aug 20, 2007 |
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60935492 |
Aug 16, 2007 |
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60935226 |
Aug 1, 2007 |
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60907097 |
Mar 21, 2007 |
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60905304 |
Mar 7, 2007 |
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Current U.S.
Class: |
351/159.42 |
Current CPC
Class: |
G02C 2202/16 20130101;
G02C 7/061 20130101; G02C 7/06 20130101; G02C 2202/20 20130101 |
Class at
Publication: |
351/159.42 |
International
Class: |
G02C 7/06 20060101
G02C007/06 |
Claims
1-13. (canceled)
14. An ophthalmic lens having a far distance zone, comprising: a
diffractive optical power region for providing a first incremental
add power; a discontinuity located between the far distance zone
and said diffractive optical power region; and a progressive
optical power region for providing a second incremental add power,
wherein at least a portion of said diffractive optical power region
and said progressive optical power region are in optical
communication such that said first incremental add power and said
second incremental add power together provide a near distance add
power for a user.
15. The ophthalmic lens of claim 1, further comprising: a distance
of said progressive optical power region corresponding to
intermediate distance vision correction over which the optical
power is constant.
16. The ophthalmic lens of claim 2, wherein said distance of said
progressive optical power region has a length of approximately 1
millimeter to approximately 6 millimeters or greater.
17. The ophthalmic lens of claim 14, further comprising: a blending
of optical efficiency across at least a portion of said
discontinuity.
18. The ophthalmic lens of claim 17, wherein at least a portion of
said blending of optical efficiency occurs over a distance of
approximately 2 millimeters or less.
19. The ophthalmic lens of claim 14, wherein a portion of said lens
provides an optical add power for intermediate distance vision
correction and said optical add power is between 45% and 55% of the
optical add power required for providing a user's near distance
vision correction.
20. The ophthalmic lens of claim 14, wherein the lens has a fitting
point, and wherein the top of said diffractive optical power region
is between approximately 2 millimeters and approximately 5
millimeters below said fitting point and the top of said
progressive optical power region is between approximately 4
millimeters and approximately 8 millimeters below the top of said
diffractive optical power region.
21. The ophthalmic lens of claim 14, wherein said discontinuity is
caused by a step in optical power.
22. The ophthalmic lens of claim 14, wherein said diffractive
optical power region is located on a surface of the lens or
embedded within the lens.
23. The ophthalmic lens of claim 14, wherein said progressive
optical power region is located on a surface of the lens or
embedded within the lens.
24. The ophthalmic lens of claim 14, wherein said progressive
optical power region comprises a progressive optical power surface
generated by one of free-forming, molding, or casting.
25. The ophthalmic lens of claim 14, wherein said diffractive
optical power region is generated by one of free-forming a surface
of the lens, molding a surface of the lens, or casting a surface of
the lens.
26. The ophthalmic lens of claim 14, wherein a portion of said lens
provides an optical add power for far-intermediate distance vision
correction and said optical add power is between 20% and 44% of the
optical add power required for providing a user's near distance
vision correction.
27. The ophthalmic lens of claim 14, farther comprising a near
distance vision correction zone and a far-intermediate distance
vision correction zone, wherein said progressive optical power
region provides the optical add power for the far-intermediate
distance vision correction zone in an area below the near distance
vision correction zone.
28. A lens, comprising: a first layer having a first index of
refraction, wherein the first layer comprises a far distance zone
and a first optical element; and a second layer having a second
index of refraction different from the first index of refraction,
wherein the second layer comprises a far distance zone and a second
optical element, wherein an optical discontinuity occurs at a
boundary of the first optical element and the far distance zone of
the first layer due to a step-up in optical power between the first
optical element and the far distance zone of the first layer,
wherein the first optical element is located 4 millimeters below a
fitting point of the lens, wherein the second optical element
comprises a progressive optical power region, the progressive
optical power region contributing a second portion of a total near
distance add power of the lens, and wherein the first and second
optical elements are in optical communication such that a first
portion of the total near distance add power of the lens and the
second portion of the total near distance add power of the lens are
combined to provide the total near distance add power of the
lens.
29. The lens of claim 28, wherein the first and second optical
elements are aligned to form far-intermediate and intermediate
vision zones.
30. The lens of claim 29, wherein the far-intermediate vision zone
has an add power between approximately 20% and approximately 44% of
the total near distance add power of the lens and the intermediate
vision zone has an add power between approximately 45% and
approximately 55% of the total near distance add power of the
lens.
31. A lens comprising: a first layer having a first index of
refraction and having a first external surface and a second
internal surface, a second layer having a second index of
refraction different from the first index of refraction and having
a first internal surface and second external surface, wherein the
second internal surface of the first layer and the first internal
surface of the second layer are in physical contact to form a
single interface, and wherein said interface comprises two optical
zones, and wherein the second external surface of the second layer
provides a progression in optical power, and wherein an optical
zone of said interface and the progression in optical power are in
optical communication for providing a combined optical power for
correcting the near distance vision of a user.
32. The lens of claim 31, wherein one of the optical zones is
diffractive and comprises surface relief diffractive
structures.
33. The lens of claim 31, wherein there is a discontinuity in
optical power between the two optical zones.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 13/005,876, filed on Jan. 13, 2011, which is a
continuation of U.S. patent application Ser. No. 12/270,116, filed
on Nov. 13, 2008, which is a continuation-in-part of U.S. patent
application Ser. No. 12/059,908, filed on Mar. 31, 2008 which is a
continuation-in-part of U.S. patent application Ser. No.
11/964,030, filed on Dec. 25, 2007.
[0002] U.S. patent application Ser. No. 12/270,116 is also a
continuation-in-part of U.S. patent application Ser. No.
12/238,932, filed on Sep. 26, 2008. The contents of each of the
above-referenced applications are hereby incorporated by reference
in their entireties.
[0003] This application claims priority from and incorporates by
reference in their entirety the following provisional applications:
[0004] U.S. Appl. No. 61/013,822, filed on Dec. 14, 2007; [0005]
U.S. Appl. No. 61/030,789, filed on Feb. 22, 2008; [0006] U.S.
Appl. No. 61/038,811, filed on Mar. 24, 2008; [0007] U.S. Appl. No.
60/970,024, filed on Sep. 5, 2007; [0008] U.S. Appl. No.
60/956,813, filed on Aug. 20, 2007; [0009] U.S. Appl. No.
60/935,573, filed on Aug. 20, 2007; [0010] U.S. Appl. No.
60/935,492, filed on Aug. 16, 2007; [0011] U.S. Appl. No.
60/935,226, filed on Aug. 1, 2007; [0012] U.S. Appl. No.
60/924,975, filed on Jun. 7, 2007; [0013] U.S. Appl. No.
60/907,367, filed on Mar. 29, 2007; [0014] U.S. Appl. No.
60/978,776, filed on Oct. 10, 2007; [0015] U.S. Appl. No.
60/960,606, filed on Oct. 5, 2007; [0016] U.S. Appl. No.
60/960,607, filed on Oct. 5, 2007; [0017] U.S. Appl. No.
60/907,097, filed on Mar. 21, 2007; and [0018] U.S. Appl. No.
60/905,304, filed on Mar. 7, 2007.
BACKGROUND OF THE INVENTION
[0019] 1. Field of the Invention
[0020] The present invention generally relates to lenses. More
specifically, the present invention provides an insert having a
diffractive region that can be embedded into any host lens material
to form a multifocal lens.
[0021] 2. Background Art
[0022] There is a desire to improve the performance and cosmetic
appeal of multifocal lenses. Traditional multifocal lenses; such as
bifocal and trifocals, suffer from a number of disadvantages. As an
example, many traditional multifocal lenses have a visible
discontinuity separating each vision zone. Blended multifocals can
reduce the visibility associated with these abrupt discontinuities
but generally at the cost of rendering the blend zones optically
unusable due to high levels of distortion and/or astigmatism.
Traditional progressive lenses can provide multiple vision zones
with invisible boundaries and no image breaks but these lenses
typically have narrow vision zones and are associated with large
amounts of unwanted astigmatism.
[0023] Diffractive optical structures have many adventures over
refractive optical structures and can reduce the visibility of
discontinuities between vision zones when used to construct
multifocal lenses. However, lenses using diffractive optical
structures to date have suffered from a number of compromises
including severe chromatic aberration due to dispersion and
ghosting due to poor diffraction efficiency.
[0024] Accordingly, what is needed is multifocal lens that exploits
the advantages of diffractive optical structures to provide less
visible discontinuities while additionally reducing vision
compromises commonly associated with diffractive optics.
BRIEF DESCRIPTION OF THE DRAWINGS/FIGURES
[0025] FIG. 1 illustrates a multifocal lens according to an aspect
of the present invention.
[0026] FIG. 2 illustrates a front view and a corresponding
cross-sectional view of a first multifocal lens of the present
invention.
[0027] FIG. 3 illustrates a front view and a corresponding
cross-sectional view of a second multifocal lens of the present
invention.
[0028] FIG. 4 illustrates a front view and a corresponding
cross-sectional view of a third multifocal lens of the present
invention.
[0029] FIG. 5 illustrates a front view and a corresponding
cross-sectional view of a fourth multifocal lens of the present
invention.
[0030] FIG. 6 illustrates a process for fabricating a multifocal
lens of the present invention.
[0031] FIG. 7 illustrates a close-up view of a possible alignment
of a diffractive and a progressive optical power region in
accordance with an aspect of the present invention
DETAILED DESCRIPTION OF THE INVENTION
[0032] Aspects of the present invention provide multifocal lenses
having one or more multifocal inserts comprising one or more
diffractive regions. A diffractive region of a multifocal insert of
the present invention can provide a constant optical power or can
provide a progression of optical power, or any combination thereof.
A multifocal insert of the present invention can be fabricated from
any type of material and can be inserted into any type of bulk lens
material. A diffractive region of a multifocal insert of the
present invention can be positioned to be in optical communication
with one or more optical regions of a host lens to provide a
combined desired optical power in one or more vision zones. Index
matching layers of the present invention can be used to reduce
reflection losses at interfaces of the host lens and multifocal
insert.
[0033] A multifocal insert of the present invention can be applied
to any type of optical lens or device including ophthalmic lenses
such as, but not limited to, contact lenses, intra-ocular lenses,
corneal in-lays, corneal on-lays, and spectacle lenses.
[0034] The multifocal lens of the present invention can be a
finished lens (edge and ready to mount in a frame), a finished lens
blank (not yet edge and ready to mount in a frame), a semi-finished
lens blank (finished on at least one outer surface but not yet
finished on a second outer surface) or a non-finished lens blank
(having neither outer surface finished). Further, the present
invention allows for any reflective or diffractive optical power
including plane (i.e., no optical power).
[0035] FIG. 1 illustrates a multifocal lens 100 according to an
aspect of the present invention. The multifocal lens 100 can
comprise host lens material or layer 102 and an insert or internal
layer 104. The host lens material 102 and the insert 104 can
comprise different materials having different indices of
refraction. The host lens material 102 and the insert 104 can
comprise substantially homogeneous materials. The host lens
material 102 can have an index of refraction that ranges, for
example, from 1.30 to 2.0. The insert 104 can have a different
index of refraction that also ranges, for example, from 1.30 to 2.0
The host lens material 102 can be considered to be bulk lens
material.
[0036] The multifocal lens 100 can be finished, non-finished, or
semi-finished lens blank. The multifocal lens 100 can be a final
ophthalmic lens. The multifocal lens 100 can be subjected to or can
include modifications from any know lens processing including, but
not limited to, tinting (e.g., including adding a photochromic),
anti-reflection coating, anti-soiling coating, scratch resistance
hard coating, ultra-violet coating, selective filtering of high
energy light, drilling, edging surfacing, polishing and free
forming or direct digital surfacing.
[0037] The multifocal lens 100 can be a static lens. For example,
the multifocal lens 100 can be a bifocal, trifocal or multifocal
lens, a lens having a progressive addition surface, a lens having a
diffractive surface, a lens having a progressive region of optical
power or any combination thereof. Overall, the multifocal lens can
be any lens having one or more regions of constant or fixed optical
power, including different optical powers.
[0038] The multifocal lens 100 can be a dynamic lens. For example,
the multifocal lens 100 can be an electro-active lens, a fluid
lens, a mechanically focusing lens, or a membrane spectacle lens.
Overall, the multifocal lens 100 can be any lens capable of having
its external convex and/or concave curvature altered mechanically
or manually, or its optical power or depth of focus changed or
altered in a dynamic manner.
[0039] The insert 104 can comprise one or more diffractive regions.
The diffractive region can be a static (e.g., non-dynamic or
non-electro-active) or a dynamic electro-active diffractive region,
or any combination thereof. The diffractive region can provide
constant optical power, a progression of optical power or a
combination thereof. The diffractive region of the insert 104 can
provide discrete changes in optical power without the abrupt sag or
slope discontinuities of a conventional refractive surface. As an
electro-active diffractive region, the diffractive region can
provide an alterable optical power. The diffractive region of the
insert 104 can also be cropped or blended. Cropping can reduce the
size of the diffractive region (e.g., by removing or not forming a
portion of a concentric ring of a typical diffractive structure)
while maintaining a desired shape and effective optical power.
Overall, a diffractive region of the insert 104 can be or can
exhibit any of the characteristics (e.g., variation in shape, size,
orientation, positioning, blending, cropping, optical power
provided, fabrication, blending efficiency, etc. ) of any of the
diffractive regions described in U.S. patent application Ser. No.
12/166,526, filed on Jul. 2, 2008, which is hereby incorporated by
reference in its entirety.
[0040] The insert 104 can be fabricated as an optical film, an
optical wafer, a rigid optic or a lens blank. The diffractive
region of the insert 104 can be fabricated, for example, to have a
thickness ranging from 1 .mu.m to 100 .mu.m. As an optical film,
the insert 104 can have a thickness, for example, ranging from 50
.mu.m to 500 .mu.m. As a rigid optic lens wafer, or lens blank, the
insert 104 can be fabricated, for example, to have a thickness of
0.1 mm to 7 mm.
[0041] Surrounding the diffractive region of the insert 104 can be
a refractive region. The refractive region of the insert 104 can be
of any optical power, including plano. By including a refractive
and diffractive region of differing optical powers, the insert 104
of the present invention can be considered to be a
refractive-diffractive multifocal insert.
[0042] The host lens material 102 can have different indices of
refraction on the front and back surfaces of the multifocal lens
100. That is, the front layer of the host lens material 102 can
comprise a material that is different from a material comprising
the back layer of the host lens material 102. The front and/or back
surfaces of the multifocal lens 100 can comprise refractive optics,
elements or regions. For example, a far distance zone of the
multifocal lens 100 located in an upper region of the multifocal
lens 100 can provide plano optical power while one or more near
distance zones located in a lower region of the multifocal lens 100
can provide positive optical power. The radii of curvature of the
front and back surfaces of the multifocal lens 100 can be
predetermined so as to generate known amounts of refractive optical
power. The front, back or internal surfaces of the multifocal lens
100 can comprise progressive surfaces or regions. The progressive
regions can be added by grinding and polishing, by free-forming, or
by molding or casting.
[0043] The multifocal lens 100 can comprise one or more index
matching layers 106 (which can also be considered index mediating,
mitigating or bridging layers as may be used in the discussion
below). The index matching layers 106 can be used to reduce
reflection losses between the host lens material 102 and the insert
104. The index matching layer 10 can have, for example, a
reflective index that is substantially equal to the arithmetic mean
of the refractive indices of the host lens material 102 and the
insert 104. Additionally, the index matching layer 106 can be used
as primer layer to promote adhesion between the host lens material
102 and the insert 104 and while reducing the visibility of a
diffractive region positioned on the insert 104. Index matching
layers/mediating layers 106 may or may not be used depending upon
the difference between the indices of refraction between the host
lens material 102 and the insert 104. Additional details on the
design and use of index matching layers is described in U.S. patent
application Ser. No. 12/238,932, filed on Sep. 26, 2008, which is
hereby incorporated by reference.
[0044] the multifocal lens 100 can provide multiple vision zones
that are wider and exhibit less distortion than traditional
multifocal lenses including progressive addition lenses. Further,
the multifocal lens 100 can provide the multiple vision zones with
a significantly reduced or invisible break between adjacent vision
zones as compared to traditional bifocal or trifocal lenses. A
diffractive region of the insert 104 can provide one or more
constant, progressive or variable optical powers that can be
combined with the one or more constant, progressive or variable
optical powers provided by the surfaces of the host lens material
102. The one or more constant, progressive or variable optical
powers contributed in part by the surfaces of the host lens
material 102 can be provided by the front and/or back surfaces or
layers of the host lens material 102.
[0045] The optical powers provided by a diffractive region of the
insert 104 can be combined with the optical powers of the host lens
material 102 as described in U.S. patent application Ser. No.
12/059,908, filed on Mar. 31, 2008, U.S. patent application Ser.
No. 11/964,030, filed on Dec. 25, 2007, and U.S. patent application
Ser. No. 12/238,932, filed on Sep. 26, 2008 each of which is hereby
incorporated by reference in their entirety. In general, the
diffractive region of the insert 104 can be fabricated to provide
any desired optical power including, but not limited to, any
optical power within a range of +0.12 D to +3.00 D. Further, the
diffractive region of the insert 104 can be positioned to be in
optical communication with the optical powers provided by the host
lens material 102 to provide any desired near distance add power
with any corresponding desired intermediate distance corrective
prescription.
[0046] The multifocal lens 100 can comprise a far distance viewing
region that can comprise refractive optics (e.g., refractive
regions of the host lens material 102 in combination with
refractive regions of the insert 104). The multifocal lens 100 can
comprise one or more viewing regions (e.g., far intermediate,
intermediate and/or near viewing regions) that can comprise
refractive optics, diffractive optics or a combination thereof
(e.g., refractive regions of the host lens material 102 in
combination with diffractive regions of the insert 104.) The
multifocal lens 100 can therefore use the combination of refractive
and diffractive optics positioned on one or more surfaces or layers
to provide multiple vision zones of varying optical power. As such,
the multifocal lens 100 can be considered to be a
refractive-diffractive multifocal lens.
[0047] By locating and distributing the desired refractive curves
or diffractive structures on multiple surfaces, layers or regions
of the multifocal lens 100, each of which are in desired location
for providing an appropriate and desired optical alignment with
respect to one another, enables the multifocal lens 100 to provide
multiple vision zones that are wider than traditional multifocal or
progressive lenses as described n the related patent applications
mentioned above.
[0048] The diffractive region of the insert 104 may or may not
include an optical power discontinuity. The diffractive region of
the insert 104 may not be visible to an observer of the multifocal
lens 100. Specifically, because the diffractive structures of the
diffractive region of the insert 104 can be fabricated to have
minimal heights, the diffractive region of the insert 104 may be
nearly invisible to an observer--particularly when covered by
another layer (i.e., the front layer of the host lens material
102). Further, any discontinuity introduced by the diffractive
region's optical power can introduce little or no prismatic optical
power jump. An image break introduced by such a discontinuity can
be that of a prismatic image break, a magnification image break, a
perceived clear/blur image break, or any combination thereof. A
change in optical power of approximately 0.08 diopters (D) or
larger may be considered as introducing a discontinuity that causes
such an image break. As described in the incorporated and related
patent applications, any discontinuity can be located in a region
traversed by a wearer's line of vision between a near to far
distance region or can be located in the periphery of the
diffractive region.
[0049] Overall, the multifocal lens 100 can comprise any number of
discontinuities (including no discontinuities). One or more
discontinuities can be introduced by a single diffractive region or
by multiple diffractive regions.
[0050] As previously described, the host lens material 102 and the
insert 104 can be fabricated from any material having different
indices of refraction. The materials used to form the host lens
material 102 can be any lens material described in U.S. application
Ser. No. 12/059,908, filed on Mar. 31, 2008 or U.S. application
Ser. No. 11/964,030, filed on Dec. 25, 2007, including those listed
below in Table 1.
TABLE-US-00001 TABLE I INDEX OF ABBE MATERIAL REFRACTION VALUE
SUPPLIER CR39 1.498 55 PPG Nouryset 200 1.498 55 Great Lakes Rav-7
1.50 58 Evergreen/Great Lakes Co. Trivex 1.53 1.53 44 PPG Trivex
1.60 1.60 42 PPG MR-8 1.597 41 Mitsui MR-7 1.665 31 Mitsui MR-10
1.668 31 Mitsui MR-20 1.594 43 Mitsui Brite-5 1.548 38 Doosan Corp.
(Korea) Brite-60 1.60 35 Doosan Corp. (Korea) Brite-Super 1.553 42
Doosan Corp. (Korea) TS216 1.59 32 Tokuyama Polycarbonate 1.598 31
GE UDEL P-1700 1.634 23.3 Solvay NT-06 Radel A-300 NT 1.653 22
Solvay Radel R-5000 NT 1.675 18.7 Solvay Byry 1.70 36 Hoya Essilor
High Index 1.74 33 Essilor
[0051] The difference in the refractive indices between the host
lens material 102 and the insert 104 can be any value such as, but
not limited to, greater than 0.01. One skilled in the relevant
art(s) will appreciate how a diffractive region of the insert 104
can be designed to account for being placed between materials
having a different refractive index (e.g., an index of refraction
different from air) and provide a desired optical power. Further,
the index of refractive of the host material 102 can be larger than
the index of refraction of the insert 104. This can result in a
thinner lens as any curves of the host lens material 102 can be
made to be flatter than if the index of refraction of the host lens
material 104 was smaller.
[0052] The insert 104 can be inserted or embedded into the host
lens material 102 (with or without one or more index mediating
and/or matching layers 106) by any known lens fabrication technique
or process. For example, the insert 104 can be molded within the
host lens material 102 when the host lens material 102 is first
fabricated and/or cast from liquid resin as a lens blank. The
insert 104 can also be embedded between two lens wafers that form
the from and back components of the host lens material 102. The two
lens wafers can then be adhesively bonded together so as to form
the multifocal lens 100 as a lens blank. Additional detail on
methods of fabricating the multifocal lens 100 is provided in the
previously mentioned related patent applications.
[0053] A diffractive region of the insert 104 can be embedded as an
uncured or semi-cured resin. The diffractive region can also be
formed or inserted into the multifocal lens 100 by injection
molding, stamping, embossing or thermal forming. The diffractive
region can also be fabricated by diamond turning a mold or mold
master (for use in subsequent mold replications) that is then used
to cast a desired diffractive optic. Thus insert 104 can be, for
example, a material such as polysulfone, polyimide, polyetherimide
or polycarbonate.
[0054] The insert 104 can alternatively comprise a layer of
photo-sensitive material with uniform thickness (i.e., not
initially comprising surface relief diffractive structures). The
refractive index of the photo-sensitive material can permanently
and irreversibly change to predetermined value when exposed to
optical radiation. The photo-sensitive material may be exposed to
radiation in a pattern predetermined to form a desired diffractive
optical power region. For example, a diffractive phase profile may
be "written " on the photo-sensitive material by means of exposure
through an optical mask or a scanning laser source. The optical
radiation can be, for example, within the ultra-violet or visible
wavelength bands, although other wavelengths can be used.
[0055] FIG. 2 illustrates a front view 202 and a corresponding
cross-sectional view 204 of a multifocal lens of the present
invention. The multifocal lens depicted in FIG. 2 can be a lens
blank. The multifocal lens has a refractive region 208 and a
diffractive region 206. The refractive region 208 can provide
desired optical power in an upper region and lower region of the
multifocal lens. The refractive region 208 can be of my desired
optical power. As an example, the entire refractive region 208 can
be of plano optical power. The provided optical power can vary
within the refractive region 208 as will be understood by one
skilled in the pertinent art(s).
[0056] The diffractive region 206 is shown to be cropped. In
particular, the diffractive region 206 is shaped as a portion of a
circle but is not so limited. That is, the diffractive region 206
can comprise any shape as previously mentioned. For example, the
diffractive region can be a semi-circle. Additionally, the diameter
of the diffractive region 206 can be any value including, but not
limited to, 40 mm. The diffractive region 206 can provide a
constant optical power. As an example, the diffractive region 206
can provide +0.75 Diopters (D) of optical power. A discontinuity
may result due to a step-up or step-down in optical power between
the refractive region 208 and the diffractive region 206.
[0057] As shown in the side view 204, the multifocal lens comprises
the host less material 102 and the insert 104. As an example, the
insert 104 can be approximately 100 .mu.m thick and can have an
index of refraction of 1.60. The insert 104 can comprise the
diffractive region 206 and a refraction region 210. The refractive
region 210 can provide any optical power including plano optical
power. As such, the insert 104 can be considered to be a thin
refractive-diffractive multifocal optic.
[0058] The host lens malarial 102 that surrounds the insert 104 can
be a refractive single vision leas. The host lens material can be
finished on the front convex curvature and can be unfinished on the
back side of the semi-finished lens blank. The host lens material
can have any index of refraction, including, but not limited to, a
refractive index within the range of 1.30 to 2.00.
[0059] The optical power of an upper region of the multifocal lens
(e.g., the optical power of the overall refractive region 208) can
be provided by the refractive region 210 of the insert 104 and the
refractive regions of the host lens material 102. The optical power
of a lower region of the multifocal lens can be provided by the
diffractive region 206 of the insert 104. Once the back unfinished
surface is finished by surfacing or free forming, the multifocal
lens depicted FIG. 2 can be a bifocal lens having an add power of
+0.75 D. In general, the total add power of the multifocal lens
depicted in FIG. 2 can be any add power as contributed by the
diffractive structure.
[0060] FIG. 3 illustrates a front view 302 and a corresponding
cross-sectional view 304 of multifocal lens of the present
invention. The multifocal lens depicted in FIG. 3 can be a lens
blank. The diffractive region 206 can be a progressive diffractive
region. Specifically, a top 306 of the diffractive region 206 can
begin or start with a minimum optical power that can increase to a
maximum optical power at a maximum optical power region 308. The
diffractive region 206 can be formed by cropping.
[0061] As an example only, the minimum optical power can be plano
optical power and the maximum optical power can be +1.75 D.
Alternatively, the minimum optical power can be +0.25 D optical
power and the maximum
[0062] optical power can be +1.00 D. A discontinuity may or may not
result due to a step-up or step-down in optical power between the
refractive region 208 and the diffractive region 206. For example,
if the diffractive region 206 begins with an optical power that is
substantially the same as the optical power provided by the
adjacent portion of the refractive region 208, then no
discontinuity may result. Alternatively, if the diffractive region
206 begins with an optical power that is different than the optical
power provided by the adjacent portion of the refractive region
208, then a discontinuity may result.
[0063] As shown in the side view 304, the multifocal lens comprises
the host lens material 102 and the insert 104. As an example, the
insert 104 can range from approximately 0.1 mm to 1 mm thick and
can have an index of refraction of 1.60.
[0064] The host lens material 102 that surrounds the insert 104 can
be a refractive single vision lens. The host lens material can be
finished on the front convex curvature and can be unfinished on the
back side of the semi-finished lens back. The host lens material
can have an index of refraction, for example, of 1.49. The optical
power of a lower region of the multifocal lens (e.g., one or more
near distance vision zones) can be provided by the progressive
diffractive region 206 of the insert 104.
[0065] Once the back unfinished surface is finished by surfacing or
free forming, the multifocal lens depicted in FIG. 3 can provide
multiple vision zones with multiple or varying optical powers
provided by the progressive diffractive structure 206. When the
multifocal lens is finished, and the progressive structure begins
with a power that is substantially the same as a power provided in
a distance region (e.g., a top 306 of the diffractive region 206
and the refractive region 210 are both plano), then the multifocal
lens can be considered a multifocal progressive addition lens.
Alternatively, when the multifocal lens is finished, and the
progressive structure begins with a power that varies from a power
provided in a distance region (e.g., a top 306 of the diffractive
region 206 and the refractive region 210 are not both plano), then
the multifocal lens may be considered to be different from a
traditional progressive addition lens yet still provide a
progression of optical powers.
[0066] The multifocal lens depicted in FIG. 3 can have its front
surface and or back surface free formed or digital surfaced to
provide an additional incremental add power region. Further, this
additional incremental add power can comprise a spherical add power
or a progressive optical power and can be in optical communication
with the diffractive structure 206.
[0067] FIG. 4 illustrates a front view 402 and a corresponding
cross-sectional view 404 of a multifocal lens of the present
invention. The multifocal lens depicted in FIG. 4 can be a lens
blank. The diffractive region 206 can be a progressive diffractive
region. Specifically, a top 306 of the diffractive region 206 can
begin or start with a minimum optical power that can increase to a
maximum optical power at a maximum optical power region 308. The
diffractive region 206 can be formed by cropping.
[0068] As an example only, the minimum optical power can be +0.01 D
(or, e.g., +0.25 D) and the maximum optical power can by +1.00 D. A
discontinuity may result due to a step-up in optical power between
the refractive region 208 and the diffractive region 206 (e.g., if
the diffractive structure 206 contributes to an optical power that
is 0.08 D or greater). For example, the refractive region 208 may
be of plano optical power such that a step-up in optical power
results between the refractive region 208 and the diffractive
region 206.
[0069] The multifocal lens can further comprises a progressive
optical power region 406. The progressive optical power region 406
can be refractive progressive optical power region. The progressive
optical power region 206 can be located on the front or back
surface of the multifocal lens. For example, the progressive
optical power region 206 can be added by molding or by
free-forming. The refractive progressive optical power region 206
can be positioned anywhere on a surface of the multifocal lens so
that any portion can overlap any portion of the diffractive
structure 206. The progressive optical power region 406, as an
example, can begin with plano optical power and can increase to
+1.00 D of the optical power. As such, the progressive optical
power region 406 can provide a first incremental add power and the
diffractive structure 20 can provide a second incremental add
power. Together, when aligned and in proper optical communication
with one another, the first and second incremental add powers can
provide a total add power of +2.00 D.
[0070] As shown in the side view 304, the multifocal lens comprises
the host lens material 102 and the insert 104. As an example, the
insert 104 can range from approximately 0.1 mm to 1 mm thick and
can have an index of refraction of 1.60.
[0071] The host lens material 102 that surrounds the insert 104 can
be a refractive multifocal lens. The host lens material can be
finished on the front convex curvature and can be unfinished on the
back side of the semi-finished lens blank. The host lens material
can have an index of refraction, for example, of 1.49. The optical
power of a lower region of the multifocal lens can be provided by
the progressive diffractive region 206 of the insert 104 in optical
communication with the progressive optical power region 406 of the
host lens material. Additionally, one or more vision zones in the
lower region of the multifocal lens can be solely more vision by
the diffractive structure 206.
[0072] Once the back unfinished surface is finished by surfacing or
free forming, the multifocal lens depicted in FIG. 4 can provided
multiple vision zones with multiple or varying optical powers that
can be provided by the progressive diffractive structure 206 alone
or in combination with the progressive optical power region
406.
[0073] In general, according to an aspect of the invention, a
diffractive region of an insert of the present invention can
provide a first incremental add power and a refractive region of a
surface of bulk lens material can provide a second incremental add
power. Together, the first and second incremental add powers can
provide a total desired add power for a multifocal lens of the
present invention. This can be accomplished by ensuring that the
diffractive region of the insert (at least a portion thereof) is in
optical communication with the refractive region (or regions) of
the bulk lens material. Further, the diffractive region of the
insert and the refractive region (or regions) of the bulk lens
material can be oriented or aligned to form multiple vision zones
having various optical powers as will be appreciated by one skilled
in the pertinent art(s).
[0074] According to an aspect of the present invention, the
diffractive region of an insert of the present invention can
provide 20% to 100% of the total desired add power of an overall
lens. In many designs, it may be desired for the diffractive region
to provide 30% or approximately 33% of a total desired add power of
a lens. Given an add power contribution provided by the diffractive
region, an add power of the refraction regions (s) of the bulk lens
material can be determined. Further, in many designs, the add power
of the diffractive region can vary from +0.125 D to +3.00 D in
steps of 0.125 D.
[0075] FIG. 5 illustrates a front view 502 and a corresponding
cross-sectional view 504 of a multifocal lens of the present
invention. The multifocal lens depicted in FIG. 5 can be a lens
blank. The diffractive region 206 can provide a constant optical
power. The diffractive region 206 be formed by cropping. As an
example, the diffractive region 206 can provide +0.75 D of optical
power. A discontinuity may result due to a step-up in optical power
between the refractive region 208 and the diffractive region 206.
For example, the refractive region 208 may be of any optical power,
including plano optical power, such that a step-up in optical power
results between the refractive region 208 and the diffractive
region 206.
[0076] The multifocal lens can further comprise a progressive
optical power region 406. The progressive optical power region 406
can be positioned anywhere on the multifocal lens and be positioned
to be in optical communication with the diffractive region 206. The
progressive optical power region 406 can be a refractive
progressive optical power region. The progressive optical power
region 206 can be located on the front or back surface of the
multifocal lens. As an example, the progressive optical power
region 406 can begin with plano optical power and can increase to
+1.25 D of optical power. As such, the progressive optical power
region 406 can provide a first incremental add power and the
diffractive structure 206 can provide a second incremental add
power. Together, the first and second incremental add powers can
provided a total add power of +2.00 D.
[0077] As shown in the side view 504, the multifocal lens comprises
the host lens material 102 and the insert 104. As an example, the
insert 104 can range
[0078] from approximately 0.1 mm to 1 mm thick and can have an
index of refraction of 1.60.
[0079] The host lens material 102 that surrounds the index of 104
can be a refractive multifocal lens. The host lens material can be
finished on the front convex curvature and unfinished on the back
side of the semi-finished lens blank. The host lens material can
have an index of refraction, for example, of 1.49. The optical
power of a lower region of the multifocal lens can be provided by
the progressive diffractive region 206 of the insert 104 in optical
communication with the progressive optical power region 406 of the
host lens material. Additionally, one or more vision zones or
regions can be located at or preferably below a fitting point of
the lens and can be solely provided by the diffractive structure
206. The fitting point of the lends can be a point on the lens that
will align with the center of a wearer's pupil.
[0080] Once the back unfinished surface is finished by surfacing or
free forming, the multifocal lens depicted in FIG. 5 can provide
multiple vision zones with multiple or varying optical powers
provided by the progressive diffractive structure 206 alone or in
combination with the progressive optical power region 406. The
progressive optical power region 406 can begin above or below the
diffractive region 206. Based on the positioning of the progressive
optical power region 406 and the optical powers of the progressive
optical power region 406 and the diffractive region 208 of the lens
and a near vision region of the lens.
[0081] In general, a refractive-diffractive multifocal insert of
the present invention can be combined with one or more other
layers, surfaces or optics as described in more detail in any of
the previously mentioned related patent applications that have been
incorporated by reference.
[0082] FIG. 7 illustrates a close-up view of possible alignment and
positioning of the diffractive region 206 and the progressive
optical power region 406 in accordance with an aspect of the
present invention. Specifically, FIG. 7 depicts a possible overlap
between the upper portions of the diffractive region 206 and the
progressive optical power region 406. The diffractive structures of
the diffractive region 206 are not shown in FIG. 7 for clarity only
(instead, only a boundary of the diffractive region 206 is
depicted).
[0083] As shown in FIG. 7, a top 702 of the progressive optical
power region 406 is aligned with the top of the diffractive region
206. A first distance 704 can correspond to a first change in the
optical power provided by the progressive optical power region 406.
Specifically, the first change can be from a beginning optical
power value (e.g., zero D) to a first optical power value. A second
distance 706 can correspond to a second change in the optical power
provided by the progressive optical power region 406. Specifically,
the second change can be from the first optical power value to a
second optical power value. A third distance 708 can correspond to
a third changes in the optical power provided by the progressive
optical power region 406. Specifically, the changes can be from a
second optical power value to a third optical power. Accordingly,
as shown in FIG. 7, the progressive optical power region 406 can
change from a starting optical power at the top 702 of the
progressive optical power region 406 to a third optical power value
by the end of a third distance 708.
[0084] The length of the first, second and third distances 704, 706
and 708, as well as the corresponding first. second and third
optical power values can be adjusted and modified to accommodate
any ramp-up in optical power within the progressive optical power
region 406. For a sharp ramp up in optical power, the distances
704, 706 and 708 can be designed to be short and/or the power
changes within each zone can be high. For slow ramp up in optical
power, the distances 704, 706, and 708 can be designed to be
extended and/or the power changes within each zone can be low. In
general, the distances 704, 706 and 708 and corresponding power
changes values can be designed to be any value.
[0085] As an example, each of the distances 704, 706 and 708 can be
1 mm in length and the changes In optical power can be +0.03 D in
the first distance 704, +0.03 D in the second distance 706, and
+0.04 D in the third distance 708. Under this scenario, the first
optical power value is +0.03 D, the second optical power value is
+0.06 D, and the third optical power value is +0.1 D.
[0086] As previously mentioned, the shape of the diffractive region
206 is not limited to the shape depicted in FIG. 7. That is, the
diffractive region 206 can be any shape resulting from cropping
including a portion of a circle. Any shaped diffractive region 206
can have a top that is aligned with a top or start 702 of the
progressive optical power region 406 as shown in FIG. 7.
[0087] A multifocal lens comprising an embedded or buried
refractive-diffractive multifocal insert optic of the present
invention can be fabricated according to any of the methods
described in the related and incorporated patent applications. As
an example, the refractive diffractive multifocal insert optic of
the present invention can comprise a preform. One or more external
refractive layers can be added to the preform by casting and curing
an optical grade resin on top of the preform.
[0088] An example of this process is shown in FIG. 6. FIG. 6 shows
a preform 602. The perform preform 602 can comprise a
refractive-diffractive multifocal optic of the present invention.
The preform 602 comprises a refractive region and a diffractive
region 604. The diffractive region 604 can be cropped. A resin
layer 606 can be cast on top of the preform 602 to form a
multifocal lens 608 of the present invention. The resin layer 606
can form a front surface of the multifocal lens. The resin layer
606 can be later finished to include a progressive region. The
resin layer 606 can be cast and cured on preform 602. The resin
layer 606 or layer 602 can be photochromatic, polarized, tinted,
include a selective high energy wavelength filter, or can form a
portion of an electro-active element. If layer 602 is
photochromatic then layer 606 can be selected of a material so as
to block as little ultraviolet (UV) light as possible.
[0089] In the description above, it will be appreciate by one
skilled in the pertinent art(s) that the diffractive structures
employed above can be replaced with refractive surface relief
Fresnel optical power regions. Surface relief Fresnel optical power
regions can comprise a series of optical zones that represent the
shape of a conventional refractive surface relief optical power
region but modulated over a pre-determined thiclmess. Such smface
relief Fresnel optical power regions can be superimposed on a
substrate having a lmnown refractive index. As is the case for
refractive optics, Snell's law applies and can be used for
designing the surface relief Fresnel optical power regions. For a
given design of a surface relief Fresnel optical power region, the
angle at which the light rays will be bent will be determined by
the refractive index values of the materials forming the surface
relief Fresnel optical power regions and the incident angle of said
light rays.
Conclusion
[0090] While various embodiment of the present invention have been
described above, it should be understood that they have been
presented by way of example and not limitation. As such, all
optical powers, add powers, incremental add powers, optical power
ranges, refractive indices, refractive index ranges, thicknesses,
thickness ranges, distances from the fitting point of the lens, and
diameter measurements that have been provided are examples only and
are not intended to be limiting. It will be apparent to one skilled
in the pertinent art that various changes in form and detail can be
made therein without departing from the spirit and scope of the
invention. Therefore, the present invention should only be defined
in accordance with the following claims and their equivalents.
* * * * *