Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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METHOD OF MANUFACTURING AN ELECTRO-ACTIVE LENS
FIELD OF THE INVENTION
[0001] The present invention relates to an efficient method of manufacturing
an
electro-active lens.
SUMMARY OF THE INVENTION
[0002] In an exemplary embodiment of the invention, a method of manufacturing
an
electro-active lens from a lens blank is disclosed. The lens blank comprises a
front
surface, a back surface, a thickness and an index of refraction. An electro-
active
element may be placed on either the front or back surface of the lens blank.
The
method further comprises forming a covering layer over the surface of the lens
blank
containing the electro-active element.
[0003] In another exemplary embodiment, another method of manufacturing an
electro-active lens is disclosed. The method comprises molding a lens blank
having
a front surface, a back surface, a thickness and an index of refraction around
an
electro-active element.
[0004] Aspects of the present invention will now be described in more detail
with
reference to exemplary embodiments thereof as shown in the appended drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] Figure 1 is a flow chart of a method of manufacturing an electro-active
lens
according to an exemplary embodiment of the invention.
[0006] Figure 2 is a flow chart of a method of manufacturing an electro-active
lens
according to an exemplary embodiment of the invention.
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[0007] Figures 2A-2F illustrate a lens at various stages in the method shown
in
Figure 2.
[0008] Figure 3 illustrates a top view of a semi-finished fly-away mold gasket
according to an exemplary embodiment of the invention.
[0009] Figure 4 illustrates a cross-section of the semi-finished fly-away mold
gasket
of Figure 3.
[0010] Figure 5 is a flow chart of a method of manufacturing an electro-active
lens
according to another exemplary embodiment of the invention.
[0011] Figures 5A-5F illustrate a lens at various stages in the method shown
in
Figure 5.
[0012] Figure 6 is a flow chart of a method of manufacturing an electro-active
lens
according to yet another exemplary embodiment of the invention.
[0013] Figures 6A-6E illustrate a lens at various stages in the method shown
in
Figure 6.
[0014] Figure 7 is a flow chart of a method of manufacturing an electro-active
lens
according to an exemplary embodiment of the invention.
[0015] Figures 7A illustrate an electro-active lens manufactured by the method
described in Figure 7.
[0016] Figures 8A-8C illustrate conductive bus arrangements according to
alternative embodiments of the invention.
[0017] Figure 9A-9C illustrate an exemplary embodiment of an electro-active
lens
having conductive bus arrangements.
[0018] Figure l0A illustrates a rear view of a spectacles frame having an
electro-
active lens manufactured according to an exemplary embodiment of the
invention.
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[0019] Figure lOB illustrates a top view of a spectacles frame having an
electro-
active lens manufactured according to an exemplary embodiment of the
invention.
[0020] Figures 11A and 11B illustrate an alternative embodiment of the
spectacles
frame of Figures l0A and lOB having an electro-active lens manufacture
according
to an exemplary embodiment of the invention.
[0021] Figures 12A and 12B illustrate an alternative embodiment of the
spectacles
frame of Figures l0A and lOB having an electro-active lens manufacture
according
to an exemplary embodiment of the invention.
[0022] Figure 13A-13D illustrate a battery attachment mounted on or near a
frame
hinge according to an exemplary embodiment of the invention.
[0023] Figure 14 illustrates integrated electrical components for use in
manufacturing an electro-active lens according to an exemplary embodiment of
the
invention.
[0024] Figure 15 illustrates another embodiment of integrated electrical
components
for use in manufacturing an electro-active lens according to an exemplary
embodiment of the invention.
[0025] Figure 16 is a flow chart of a method of finishing and mounting
integrated
electronic components in manufacturing an electro-active lens according to
still
another exemplary embodiment of the invention.
[0026] Figures 16A-16E illustrate a lens at various stages in the method shown
in
Figure 16.
[0027] Figure 17 is a flow chart of a method of finishing a lens with
electronic
components in manufacturing an electro-active lens according to another
exemplary
embodiment of the invention.
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[0028] Figures 17A-17E illustrate a lens at various stages in the method shown
in
Figure 17.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0029] In 1998, there were approximately 92 million eye examinations performed
in
the United States alone. The vast majority of these examinations involved a
thorough check for eye pathology both internal and external, analysis of
muscle
balance and binocularity, measurement of the cornea and, in many cases, the
pupil,
and finally a refractive examination, which was both objective and subjective.
[0030] Refractive examinations are performed to understand/diagnose the
magnitude and type of the refractive error of one's eye. The types of
refractive error
that are currently able to be diagnosed & measured, are myopia, hyperopia,
astigmatism, and presbyopia. Current refractors (phoropters) attempt to
correct one's
vision to 20/20 distance and near vision. In some cases, 20/15 distance vision
can be
achieved; however, this is by far the exception.
[0031] It should be pointed out that the theoretical limit to which the retina
of one's
eye can process and define vision is approximately 20/08. This is far better
than the
level of vision which is currently obtained by way of both today's refractors
(phoropters) and conventional spectacle lenses. What is missing from these
conventional devices is the ability to correct for non-conventional refractive
error,
such as aberrations, irregular astigmatism, or ocular layer irregularities.
These
aberrations, irregular astigmatism, and/or ocular layer irregularities may be
a result
of one's visual system or a result of aberrations caused by conventional
eyeglasses,
or a combination of both.
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[0032] In accordance with exemplary embodiments of the invention, methods of
manufacturing an electro-active lens are disclosed. The electro-active lens
may be
used to provide vision correction for one or more focal lengths, and may
further
correct non-conventional refractive error including higher order aberrations.
[0033] To assist with understanding certain embodiments of the invention,
explanations of various terms are now provided. "Attaching" can include
bonding,
depositing, adhering, and other well-known attachment methods. A "controller"
can
include or be included in a processor, a microprocessor, an integrated
circuit, a
computer chip, and/or a chip. A "conductive bus" operates to conduct data in
the
form of an electrical signal from one place to another place. "Near distance
refractive error" can include presbyopia and any other refractive error needed
to be
corrected for one to see clearly at near distance. "Intermediate distance
refractive
error" can include the degree of presbyopia needed to be corrected an
intermediate
distance and any other refractive error needed to be corrected for one to see
clearly
at intermediate distance. "Far distance refractive error" can include any
refractive
error needed to be corrected for one to see clearly at far distance. "
Conventional
refractive error" can include myopia, hyperopia, astigmatism, and/or
presbyopia.
"Non-conventional refractive error" can include irregular astigmatism,
aberrations of
the ocular system including coma, chromatic aberrations, and spherical
aberrations,
as well as any other higher order aberrations or refractive error not included
in
conventional refractive error. "Optical refractive error" can include any
aberrations
associated with a lens optic.
[0034] In certain embodiments, a "spectacle" can include one lens. In other
embodiments, a "spectacle" can include more than one lens. A "multi-focal"
lens can
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include bifocal, trifocal, quadrafocal, and/or progressive addition lens. A
"finished"
lens blank can include a lens blank that has a finished optical surface on
both sides.
A "semi-finished" lens blank can include a lens blank that has, on one side
only, a
finished optical surface, and on the other side, a non-optically finished
surface, the
lens needing further modifications, such as, for example, grinding and/or
polishing,
to make it into a useable lens. An "unfinished" lens blank has no finished
surface on
either side. "Base lens" refers to the non-electro-active portion of a lens
blank
which has been finished.
[0035] "Surfacing" can include grinding and/or polishing off excess material
to
finish a non-finished surface of a semi-finished or unfinished lens blank. The
lens
blank may also be finished using free form machining techniques that have
recently
been adopted by the ophthalmic lens industry. Free forming techniques allow a
completely arbitrary shape to be placed on the lens blank that may be used to
complete conventional error correction, but may also be used to correct higher
order
aberrations to provide for a non-conventional error correction that may lead
to vision
correction better than 20/20. Further, the lens blank can be fabricated by
bonding
two or more lens wafers together to form a finished lens or a semi-finished
lens
blank. It should be appreciated that the lens blank, whether finished,
unfinished, or
semi-finished, may initially be fabricated using free form techniques to
correct for
either or both of conventional and non-conventional refractive error.
[0036] A method of manufacturing an electro-active lens is disclosed as shown
in
Figure 1. The method comprises providing a lens blank as shown in step 10. The
lens blank may be any type of lens blank and has a front and back surface, a
thickness, and an index of refraction. In step 20, an electro-active element
is placed
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on either the front or back surface of the lens blank. In step 30, a covering
layer is
formed over the surface of the lens blank containing the electro-active
element. This
covering layer protects the electro-active element and fixes the electro-
active
element at a location on the lens blank. The material used to create the
covering
layer may also, in combination with the lens blank, provide a fixed distance
vision
correction to a wearer of the lens.
[0037] The electro-active element may comprise one or more layers of electro-
active material, such as a polymer gel and/or liquid crystals which, when
activated
by an applied electrical voltage, produce an index of refraction which is
variable
with the amount of the electrical voltage applied to the electro-active
material.
When a wearer views through an area of the electro-active lens containing the
electro-active element, the wearer may achieve vision correction based on the
index
of refraction of the electro-active element, which may be in addition to
vision
correction provided by the non-electro-active portion of the lens. Suitable
electro-
active materials include various classes of liquid crystals and polymer gels.
These
classes include nematic, smectic, and cholesteric liquid crystals, polymer
liquid
crystals, polymer dispersed liquid crystals, and polymer stabilized liquid
crystals as
well as electro-optic polymers.
[0038] If liquid crystals such as nematic liquid crystals are used as the
electro-active
material, an alignment layer may be required because nematic and many other
liquid
crystals, are birefringent. That is, they display two different focal lengths
when
exposed to unpolarized light absent an applied voltage. This birefringence
gives rise
to double or fuzzy images on the retina. To alleviate this birefringence, a
second
layer of electro-active material may be used, aligned orthogonal to the first
layer of
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electro-active material. In this manner, both polarizations of light are
focused
equally by both of the layers, and all light is focused at the same focal
length.
[0039] Alternatively, the use of cholesteric liquid crystals, which have a
large chiral
component, may be used instead as a preferred electro-active material. Unlike
nematic and other common liquid crystals, cholesteric liquid crystals do not
have the
polarity of nematic liquid crystals, avoiding the need for multiple layers of
electro-
active material.
[0040] Various electro-active layers which may be used in the electro-active
element of embodiments of the present invention are described in
PCT/US03/12528
filed April 23, 2003 which is herein incorporated by reference in its
entirety.
[0041] The lens blank may be any type of lens blank and may include, for
example,
a semi-finished blank, an unfinished lens blank, a lens wafer, a preformed
optic or a
finished lens. The covering layer may be formed by conformal sealing such as
by
molding or surface-casting, or by covering the lens blank with a lens wafer.
[0042] In an exemplary embodiment of the invention, an electro-active lens is
manufactured from a semi-finished blank, with a covering layer formed by
conformal sealing. An electro-active element may be placed on either the front
or
back surface of the semi-finished blank. The conformal seal forms a protective
covering layer over the surface of the lens blank on which the electro-active
element
was placed, burying the electro-active element within the lens. Figure 2 is a
flow
chart which illustrates a method of manufacturing the electro-active lens
using
conformally sealed semi-finished blanks according to an embodiment of the
invention. Figures 2A-E illustrate the lens at various stages of the method
illustrated
in Figure 2. At step 100, a semi-finished blank 230, having a back concave
surface
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202 and a front convex surface 204, may be selected, as shown in Figure 2A. At
step 110, a recess 205 may be cut in the front convex surface 204 of the semi-
finished blank 230, as shown in Figure 2B. At step 120, an electro-active
element
200 may be placed in the recess 205. Additionally, a conductive bus 210
connected
to the electro-active element 200 may be placed in the recess 205. Preferably,
the
conductive bus 210 may be constructed of an optically transparent, flexible
material,
such as an extruded or cast polymer film of ophthalmic grade material which
has
been coated with a transparent conducting material such as indium-tin-oxide
and/or
conductive polymers. The conductive bus 210 may have a plurality of apertures,
which may promote better bonding of the conductive bus to the lens blank 230.
[0043] At step 130, the electro-active element 200 and the conductive bus 210
can
be conformally sealed into the semi-finished blank 230, as shown in Figure 2D,
using a mold 220 containing a sealant, such as an optically clear resin, which
preferably has an index of refraction near or equal to the index of refraction
of the
lens blank.
[0044] The electro-active element 200 and the conductive bus 210 is placed in
the
mold 220 and capped with the lens blank 230. The resin may be cured by way of
example only, by thermal energy, light energy, or a combination of the two.
Light
sources may include any one of or a combination of visible, ultraviolet or
infrared
sources.
[0045] At step 140, the semi-finished blank 230 can be demolded as shown in
Figure 2E to provide a semi-finished electro-active lens blank 235. The cured
resin
creates a covering layer 215 over the front convex surface 204, which has the
effect
of burying the electro-active element 200 and conductive bus 210 within the
electro-
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active lens. The electro-active lens blank 235 has a covering surface 208
having a
radius of curvature equal to that of the mold 220. The radius of curvature of
the
covering surface 208 in combination with the radius of curvature of the back
concave surface 202 provides the fixed optical power.
[0046] A hard, scratch-resistant coating may optionally be applied to the lens
as
shown in step 150. Hard coating may be accomplished by dipping or spin coating
the lens prior to finishing the semi-finished electro-active lens blank 235.
It should
be appreciated that the hard coating may be applied to an inner surface of
mold 220
before filling the mold with resin and curing the resin to the front convex
surface
204 of the lens blank, such that when the resin has cured and the covering
layer is
formed, the hard coat is already on the covering surface 208.
[0047] At step 160, the semi-finished electro-active lens blank 235 can be
finished
to a desired prescription, as shown in Figure 2F, by surfacing the electro-
active lens
blank 235 by known techniques to produce an electro-active lens 240. The
electro-
active lens 240 may subsequently be edged to fit in a spectacles frame.
[0048] It should be appreciated that the front convex surface 204 and back
concave
surface 202 of the lens blank 230 may have any or no degree of curvature,
which
may later be applied through various surfacing techniques. Once the lens blank
230
has been conformally sealed to bury the electro-active element 200 and
conductive
bus 210, the final degree of curvature imparted to back concave surface 202
and the
covering surface 208 after finishing, not the front convex surface 204,
determines
the optical characteristics of the electro-active lens 240.
[0049] In an exemplary embodiment of the invention, the manufacturing of the
electro-active lens uses a preformed optic such as, but not limited to a
finished, or
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single vision lens, for example. Figure 6 illustrates a method of
manufacturing an
electro-active lens from a lens blank which is a single vision lens using a
conformal
sealing approach similar to that described above in relation to Figure 2 to
create a
covering layer to contain the electro-active element within the lens. However,
unlike the semi-finished blank described with respect to the method in Figure
2, a
single vision lens already has a prescription and does not need further
surfacing to
provide the correct fixed optical power to a wearer of the lens. Accordingly,
in this
embodiment, the conformal sealing is preferably done in such a manner as to
not
change the power of the original finished lens. This may be accomplished, for
example, by using a mold to produce a radius of curvature on the covering
surface of
the covering layer equal to that of the front convex surface of the single'
vision lens.
However, it should be appreciated that even if a finished single vision lens
is used,
the optical power may be changed if desired by using a mold to produce a
covering
layer having a covering surface which has a desired curvature different from
that of
the front convex surface of the single vision lens.
[0050] As shown in Figure 6, at step 700, a single vision base lens 800 can be
selected, as further shown in Figure 6A. At step 710, a recess 810 may be cut
into
the front convex surface 804 of the single vision base lens 800 shown in
Figure 6B.
Alternatively, the single vision base lens 800 may already have a recess 810,
such as
may have been formed in the single vision base lens 800 during its original
manufacture. At step 720, an electro-active element 200 and conductive bus 210
may be placed in the recess 810 as shown in Figure 6C. At step 730, the
electro-
active element 200 and bus 210 are conformally sealed using a resin-containing
mold 820 as shown in Figure 6D. At step 740, the mold 820 is removed and a
hard
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coating may optionally be applied. In certain embodiments the hard coat is
transferred from the mold during the conformal sealing. In this case the inner
concave surface of the mold used to produce the convex covering surface 808 of
the
covering layer would have been pre-coated with a hard coat resin that is cured
and
transferred in the conformal sealing process. Because the single vision base
lens
described in this example may already be finished to have a desired fixed
optical
power prior to conformal sealing, the inner surface of the mold 820 is
preferably
concave with a radius of curvature equal to that of the front convex surface
804 of
the single vision base lens 800. This yields a convex covering surface 808
upon
removal of the single vision base lens 800 from the mold 820 after conformal
sealing which is substantially identical in curvature to that of the front
convex
surface 804, as shown in Figure 6E, resulting in little to no change in the
fixed
optical power of the single vision base lens 800.
[0051] Use of conformal sealing in the manufacture of an electro-active lens
can
reduce the number of stock-keeping-units (SKUs) to 539, a significant
reduction
compared to the number of SKUs commonly required for conventional lenses.
[0052] To understand the significance of this improvement, one must understand
the
number of traditional lens blanks needed to address most prescriptions. About
95%
of corrective prescriptions include a sphere power correction within a range
of -6.00
diopters to +6.00 diopters, in 0.25 diopter increments. Based on this range,
there are
about 49 commonly prescribed sphere powers. Of those prescriptions that
include an
astigmatism correction, about 90% fall within the range of -4.00 diopters to
+4.00
diopters, in 0.25 diopter increments. Based on this range, there are about 33
commonly prescribed astigmatic (or cylinder) powers. Because astigmatism has
an
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axis component, however, there are about 180 degrees of astigmatic axis
orientations, which are typically prescribed in 1 degree increments. Thus,
there are
180 different astigmatic axis prescriptions.
[0053] Moreover, many prescriptions include a bifocal component to correct for
presbyopia. Of those prescriptions that have a presbyopic correction, about
95% fall
within the range of +1.00 to +3.00 diopters, in 0.25 diopter increments,
thereby
resulting in about 9 commonly prescribed presbyopic powers.
[0054] This results in the possibility of 2,619,540 (49 x 33 x 180 x 9)
different lens
prescriptions, requiring a very large number of SKUs for a lens manufacturer.
This
large number of SKUs is further increased due to the variety of raw materials
available for lens manufacturing as well as other special features available
for
inclusion in lens such as photochromic tints. By providing most vision
correction
electro-actively, the number of SKUs is greatly reduced.
[0055] In another exemplary embodiment of the invention, the electro-active
lens is
manufactured by attaching two lens wafers together, with an electro-active
element
sandwiched between the two lens wafers.
[0056] As shown in Figure 7, at step 1000, a front and back lens wafer may be
selected to have the desired optical characteristics for the fixed distance
refractive
power to match a wearer's vision prescription. As shown in Figure 7A, a
concave
back lens wafer 900 and a convex front lens wafer 930 are selected. The front
lens
wafer 930 may have a radius of curvature of R1, while the back lens wafer 900
may
have a radius of curvature R2. The fixed optical power of the lens wafers
equals (n-
1) x (1/Rl - 1/RZ), where "n" equals the index of refraction of the material
used to
manufacture the lens wafers. Where both Rl and RZ are parallel to one another,
the
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resulting base lens formed by attaching the lens wafers has a fixed optical
power of
zero.
[0057] As with other the electro-active lenses described herein, optical power
for
near and intermediate vision correction results from the addition of the fixed
optical
power, which typically provides optical power to provide far distance vision
correction, plus the optical power provided by viewing through an area of the
electro-active lens containing the electro-active element. It should be
appreciated,
however, that any lens may be manufactured to have a fixed optical power which
equals zero such that all vision correction is provided by viewing through the
area of
the electro-active lens containing the electro-active element. Likewise,
viewing
through the area of the lens containing the electro-active element may provide
correction of non-conventional refractive error, including correction of
higher order
aberrations, for all focal lengths.
[0058] It should further be appreciated that through the use of customized
casting,
free-form manufacturing, or light initiated refractive index changes or light
initiated
refraction changes, it is possible to correct for non-conventional refractive
error
using the base lens only or in combination with the electro-active element. In
these
embodiments, the base lens may provide correction of non-conventional
refractive
error independent of the electro-active element, which may correct for
spherical
power adjustments or errors associated with conventional refractive error such
as
presbyopia.
[0059] Referring again to Figure 7A, a recess may be cut into either one or
both of
the surface opposite the convex surface of the front lens wafer 930 and the
surface
opposite the concave side of the back lens wafer 900. Alternatively, a recess
may
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already be present in the lens wafers 900, 930, having been previously
created, such
as at the time of manufacture. Figure 7A illustrates the front lens wafer 930
having
a single recess 940 in the surface opposite the convex surface of the front
lens wafer
930. An electro-active element 910 and a flexible conductive bus 920 may be
placed between the back lens wafer 900 and the front lens wafer 930, the
electro-
active element 910 and the flexible conductive bus 920 situated to fit within
the
recess 940. As described in step 1030, the front lens wafer 930 and the back
lens
wafer 900 may be bonded together with an index matched adhesive, to produce an
electro-active lens.
[0060] In certain embodiments, the electro-active lens may be manufactured
from
laminated lens wafers, with the back lens wafer providing cylinder power and
the
combination of the back and front lens wafers completing the sphere power of
the
lens.
[0061] It should be appreciated that in certain embodiments in the manufacture
of
an electro-active lens, step 1010 as shown in Figure 7 is optional and no
recess is
required for the conductive bus and electro-active element. For example, in
certain
embodiments an electro-active element and conductive bus may be sandwiched
between two lens wafers, while maintaining the proper relationship of the two
wafers so as not to create a prismatic power unless it is desired to address
the
particular vision needs of the wearer. An index matched ophthalmic grade resin
may be applied between the layers and held in place by, way of example only, a
peripheral gasket until cured, at which point the gasket could be removed
resulting
in an electro-active lens.
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[0062] In another exemplary embodiment of the invention, an electro-active
lens
can be manufactured by molding the entire lens around an electro-active
element,
which is disposed in the bulk of the final electro-active lens product. Figure
3
illustrates a top view of a semi-finished fly-away mold gasket 610 holding an
electro-active element 200 and buses 410-413. The electro-active element 200
may
be electrically connected to four conductive buses 410, 411, 412, 413. The
conductive buses 410, 411, 412, and 413 extend from the electro-active element
200
radially outward to a mold gasket ring 420. Figure 4 illustrates a cross-
sectional
view of the semi-finished fly-away mold gasket of Figure 3, including the
electro-
active element 200 and the buses 410-413.
[0063] Figure 5 illustrates a method of manufacture of electro-active lenses
using a
fully molded semi-finished blank according to an embodiment of the invention.
At
step 500, a mold assembly which includes a top mold 600 and a bottom mold 620,
and a fly-away gasket 610 having a gasket top cavity 640, a gasket bottom
cavity
650, an electro-active element and a conductive bus may be selected, as shown
in
Figure 5A. At step 510, the gasket 610 may be placed on the bottom mold 620,
as
shown in Figure 5B. At step 520, a resin 660 can be added to the mold
assembly,
which when cured, will form the lens. The resin passes into the gasket bottom
cavity 650 through spaces between, or apertures in, the conductive buses. It
should
also be appreciated that the mold assembly shown in Figure 5D could be filled
with
a resin through a sealable aperture in the side of the gasket 610.
[0064] Ophthalmic grade resins such as those used in conformal sealing may be
used. These resins include dietilenglycol bis allylcarbonate, such as CR39~
available from PPG Industries, Inc. of Pittsburgh Pennsylvania, high index
polymers
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and other well known ophthalmic resin materials. At step 530, the top mold 600
may be positioned over the gasket top cavity 640, as shown in Figure 5D. The
resin
between the top mold 600 and bottom mold 620 is cured in step 540, as shown in
Figure 5E. At step 550, the top mold 600 and bottom mold 620 may be removed
along with the outer gasket ring 420, to produce a semi-finished electro-
active lens
blank, which may then be subjected to various finishing techniques to produce
the
finished electro-active lens.
[0065] It should be appreciated that while this embodiment describes the
molding
process in terms of cast molding, injection molding may also be used in the
manufacture of an electro-active lens. In these embodiments, a material such
as
polycarbonate, for example, may be injection molded into a die and cured
around an
electro-active element and conductive bus contained within the die to
manufacture
an electro-active lens.
[0066] Various conductive bus arrangements may be used to manufacture the
electro-active lens of the exemplary embodiments of the invention. Typically,
a bus
or group of buses may be placed in any manner to conduct electricity radially
outward from the electro-active element. As shown in Figure 8A, the electro-
active
element 200 may be electrically connected to a single conductive bus 1100. The
bus
1100 extends radially outward from the electro-active element 200. When the
bus
extends outward from the electro-active element it may also be utilized as an
electrical lead to connect a power source directly or indirectly to the
electro-active
element 200.
[0067] In another embodiment, as shown in Figure 8B, the electro-active
element
200 may be electrically connected to a plurality of conductive buses, such as
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conductive buses 1110, 1111, 1112. As with the single conductive bus of Figure
7A, each of buses 1110, 1111, 1112 may be electrically connected at one end to
the
electro-active element 200 and may extend radially outward from the electro-
active
element 200. Preferably, each of buses 1110, 1111, 1112 are spaced evenly
around
the electro-active element 200. It should be appreciated that any number of
buses
may be arranged to extend outward from the electro-active element 200 in a
full or
partial wagon-wheel configuration. Increasing the number of buses includes an
advantage of providing a larger number of positions at which electronic
components
such as a rangefinder, controller, and power supply may be placed to activate
the
electro-active element and provide electro-active vision correction.
[0068] In yet another embodiment, as shown in Figure 8C, the electro-active
element 200 may be electrically connected to a disk shaped conductive bus 1120
that
at least partially encircles the electro-active optical element 200. The
conductive
bus 1120 may comprise a plurality of perforations or apertures 1125. These
perforations 1125 may be advantageous to allow resin to flow through and
around
the conductive bus 1120 lock the electro-active element 200 into the lens
blank
during manufacturing of the electro-active lens and may enhance bonding
between
the conductive bus 1120 and lens wafers, if the electro-active lens is
manufactured
with the use of lens wafers. The conductive bus 1120 is electrically connected
at the
inner periphery of the disk to the electro-active optical element 200.
[0069] Figure 9A illustrates an electro-active lens 1200 having a conductive
bus
arrangement connected to a rangefinder and controller. The conductive bus
arrangement comprises an electro-active element 1205, an electro-active
substrate
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wafer 1210, an integrated controllerlrangefinder 1220, a base lens 1230 and
drive
signal buses 1240.
[0070] The rangefinder may comprise a transmitter and detector coupled to a
controller. In another embodiment, a single device can be fabricated to act in
dual
mode as both a transmitter and detector connected to the controller.
[0071] The controller may be a processor, microprocessor, integrated circuit,
or chip
that contains at least one memory component. The controller stores information
such as a vision prescription that may include the wearer's prescription for
several
different viewing distances. The controller may be a component of, or integral
with,
the rangefinder. It should be appreciated, however, that the controller and
rangefinder may be separate components and need not be located at identical
locations, only that the controller and rangefinder be electrically connected.
It
should also be appreciated that other view detectors, such as a micro tilt
switch to
determine a wearer's head tilt or an eyetracker to determine a wearer's line
of vision
could be used in lieu of, or in combination with, the rangefinder to determine
what
object a wearer is viewing and how the electro-active element should be
activated to
provide a focal length corresponding to the object being viewed to provide the
wearer with proper vision correction.
[0072] The rangefinder is in electronic communication with the electro-active
element, either directly or via the controller, through signals distributed
through the
conductive bus. When the rangefinder detects that the focal length produced by
the
electro-active element should be switched to provide a different focal length,
the
rangefinder may electronically signal the controller. In response to this
signal, the
controller adjusts the voltage applied to the electro-active element to
produce a
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refractive index change that by itself, or in combination with other
refractive index
changes such as provided by the fixed optical power of the base lens will
provide the
desired vision correction. This refractive index change may be used to correct
for
conventional refractive error, unconventional refractive error when the
refractive
index change is generated in a prescribed pattern using a pixilated electro-
active
element, or a combination of both conventional and non-conventional error
correction, either or both of which are consistent with a vision prescription
stored in
the memory of the controller. The new index of refraction produces the
appropriate
optical power in the electro-active lens to correspond to the change in focal
length.
[0073] In the case where non-conventional refractive error is corrected only
by the
electro-active element and not through the use of free form lens techniques, a
pixilated electro-active element is used. Non-conventional refractive error
may be
corrected by applying a voltage to the electro-active element, which creates a
refractive index change to a plurality of pixels, contained within the electro-
active
element thus creating a grid or pattern having a variety of indices of
refraction which
in combination provide for the correction of non-conventional refractive
error.
[0074] The rangefinder may use various sources such as lasers, light emitting
diodes, radio-frequency waves, microwaves, or ultrasonic impulses to locate
the
object and determine its distance. The light transmitter may be a vertical
cavity
surface-emitting laser (VCSEL) is used as the light transmitter. The small
size and
flat profile of these devices make them attractive for this application. In
another
embodiment, an organic light emitting diode, or OLED, is used as the light
source
for the rangefinder. The advantage of this device is that OLEDs can often be
fabricated in a way that they are mostly transparent. Thus, an OLED may be a
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preferable rangefinder to keep the lens aesthetically pleasing, since it could
be
incorporated into the lens or frames without being noticeable.
[0075] Referring to Figure 9B, which is a cross-sectional view from the top of
the
lens shown in Figure 9A, the controller/rangefinder 1220 may be contained
within
an electro-active substrate 1250 that may be further processed to produce an
electro-
active lens. Vias 1290 may be used to provide electrical connection to
circuitry
buried in the base lens 1230. The outer surface of the base lens 1230 may then
be
coated with transparent conductors 1293, 1296 which can be used to make
electrical
contact with a positive and negative terminal of an external power source, so
that
power can be applied to the electro-active element 1205 and the
controller/rangefinder 1220 by applying a potential across the two exterior
surfaces
of the lens.
[0076] The controller/rangefinder 1220 may be connected to the electro-active
element 1205 by a series of conductive buses, such as in any of the
configurations
described herein. Preferably, the bus may be of a wagon wheel construction
where
the buses form spokes of the wheel, with the electro-active element serving as
the
hub. The wagon wheel construction provides the option of the
controller/rangefinder 1220 being mounted on the lens 1200 in a number of
different
locations. The controllerlrangefinder 1220 may be connected at any point on
any
conductive bus 1240 and is preferably at a periphery of the lens near the
frame, or
the controller/rangefinder 1220 alternatively may be attached to the frame,
connected to the conductive bus 1240 via leads. This wagon-wheel conductive
bus
configuration also provides multiple locations to apply a voltage across the
electro-
active element 1205 from a power source.
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[0077] Alternatively, in certain embodiments an electrical conducting surface
may
be used as shown in Figure 9C. In these embodiments a conducting penetrating
mechanism, such as a clamp having a first jaw 1282 and a second jaw 1284 may
be
used, each jaw attached to opposite terminals of a power source. The jaws
1282,
1284 may be tightened such that a portion of the jaws may penetrate the
surface of
the lens 1200 or otherwise make contact with the surface of transparent
conductors
1293, 1296 and thus conducting electrical power from the power source. In
Figure
9C, the connective jaws 1282, 1284 are shown on opposite sides of the lens.
However, it should be appreciated that both jaws 1282, 1284 may penetrate the
same
side of the lens, provided that the proper insulation separates the positive
and
negative leads.
[0078] In yet another embodiment of the invention, the contacts to a power
supply,
such as a battery, may be mounted on or near a frame hinge 1305 of a spectacle
lens
which may contain an electro-active lens 1200 manufactured in accordance with
the
methods described herein. Figure 10A illustrates a rear view of a spectacles
frame
with the contacts to the power supply mounted on or near the hinge of the
frame
according to an exemplary embodiment the invention. Figure lOB illustrates a
top
view of a spectacles frame with the contacts to the battery mounted on or near
the
frame hinge according to an exemplary embodiment the invention. In some
embodiments, the power supply, such as a battery 1320, may be connected to the
lens through the front of the lens by drilling holes 1330 to the power
terminals 1380,
1385 in the lens.
[0079] In some embodiments, the controller/rangefinder 1220 is mounted in the
lens
1200 and the power to the controller/rangefinder 1220 and the electro-active
element
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1205 is supplied by a battery 1320 attached to the frame 1300. Figures l0A and
lOB illustrate an embodiment in which the contacts 1310 to the battery 1320
are
mounted on or near the frame hinge 1305, for example on the temple area of the
frame. Alternatively, as shown in Figures 11A and 11B, the contacts 1310 to
the
battery 1320 can also be made though the back of the lens 1200. The contacts
1310
may be made from transparent, conductive materials such as ITO or other
conductive oxides or with a transparent conductive polymer.
[0080] Figures 12A and 12B illustrate an alternative embodiment of the
contacts
1310 to the battery 1320 mounted on or near the frame hinge 1305. The contacts
1310 may extend through the side of the frame 1300 into the side of the lens
1200.
In such cases it may be advantageous to coat the outer edge of the lens 1200
with
two conductive strips that are electrically isolated from one another to
impede the
current being supplied to the device. These conductive strips may provide
better
surface contact and reduced impedance for the voltage being supplied to the
electro-
active element 1205.
[0081] It is also possible to use a screw and frame hinge to mount an external
power
supply to the frame. In some embodiments the controller may also be mounted to
the
frame in this manner. Figures 13A-13D illustrate a battery attachment mounted
on
the frame hinge. The battery attachment comprises a battery 1320 with an
attached
support ring 1420, a frame screw 1410, and frame hinge 1305. The battery
support
ring 1420 may be inserted in the frame hinge 1305 to receive the screw 1410.
The
screw 1410 may be inserted through the frame hinge 1305, which may be threaded
to hold the screw 1410. Figure 13D shows an alternative embodiment in which
the
battery attachment may further comprise a battery cradle 1322 from which
battery
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1320 may be removed or replaced without disengaging the screw 1410 from the
battery support ring 1420.
[0082] The controller, rangefinder, and power supply of the electro-active
lens may
be separate components placed on the lens or spectacle frame or they may be
integrated into a single module. Figure 14 illustrates an integrated battery,
controller, and rangefinder which form a single control module for use in
accordance
with exemplary embodiments of the invention. The control module may comprise,
by way of example only, a semi-circular photo-detector 1700 and a semi-
circular
light emitting diode 1710 which together form the rangefinder as a first
component
of the module. A controller 1720 may be positioned behind the rangefinder to
form
a second component, and a disk-shaped battery 1730 may be placed behind the
controller 1720. As shown in Figure 15, these components form a single control
module 1810 which can be attached to the electro-active element 1830 via a
conductive bus 1820 to provide power to the electro-active element 1830 and to
switch focal lengths of the lens 1800 to provide the required vision
correction for
wearer of the lens.
[0083] Figure 16 illustrates a method of finishing and mounting an integrated
control module into the lens. At step 1900, a layout may be selected for a
desired
spectacle frame taking into consideration the lens blank size and also the
location of
the wearer's pupils and the distance between them. At step 1910, a lens blank
1975,
which may typically be a preformed optic or semi-finished blank may be
decentered
based on the size of the lens blank and the wearer's pupil alignment. In some
cases,
decentering may also be desired to produce a desired prismatic effect. The
lens
blank may also be rotated if an astigmatic correction is provided by the non-
electro-
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active portion of the lens. At step 1920, the lens blank 1975 may be surface
cast or
ground to provide a needed distance prescription for the wearer. At step 1930,
a
recess may be cut or molded into the surface for receiving the electro-active
element
1977 and conductive bus 1979. It should be appreciated that step 1930 is
optional,
and that a recess may previously have been created. At step 1940 the electro-
active
element and conductive bus, as well as a controller/rangefinder 1981 are
inserted
within the recess and conformally sealed to bury these components within the
lens.
The bus may preferably be oriented in a location that the rangefinder and
controller
can be placed near the edge of the spectacles frame, preferably near the
temple of a
wearer.
[0084] However, it should be appreciated, that as with other embodiments, the
controller and rangefinder need not be buried within the lens, but that either
one or
both may later be added, such as by placement on a spectacles frame, or on the
lens
surface, and then electrically connected to the conductive bus contained
within the
lens. At step 1950 the lens is edged into a shape for placement within a
spectacles
frame and then mounted within that frame. When edging the lens to the fit the
spectacle frame, the lens should be edged to remove only those portions of the
lens
which do not contain the electro-active element. Finally, at step 1960 the
battery is
connected to the conductive bus. If the controller was not preprogrammed prior
to
installation, it may be programmed to contain information particular to the
wearer,
such as the wearer's vision prescription for different focal lengths.
[0085] Alternatively, any one or all of the rangefinder, controller, and
battery may
be mounted on the spectacles frame and connected to the electro-active lens
through
leads passing to the electro-active element. Figure 17 illustrates a method of
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finishing and dispensing a lens with a rangefinder, battery, and a controller
in the
spectacles frame. At step 2000, a layout may be selected. At step 2010, a
preformed optic or a semi-finished blank can be decentered and rotated as
shown in
Figure 17b. If the lens has a toric power and the electro-active element is
placed
over the optical center of the lens, the bus must be oriented relative to the
toric axis.
At step 2020, the lens may be ground to a toric and sphere shape, as
illustrated in
Figure 17C. The lens may be edged, as in step 2030, for placement in a
spectacle
frame shown in Figure 17D. At step 2040, the rangefinder, battery, and
controller,
shown as an integrated control module 2060, may be mounted on the spectacles
frame, to complete the process as shown in Figure 17E. Alternatively, it
should be
appreciated that the integrated control module may be mounted on the
spectacles
frame during frame manufacture.
[0086] If required for the wearer's vision needs, prism may be added during
the
various embodiments of manufacturing an electro-active lens. For example, if a
semi-finished blank is used, prism may be added and surfaced into the lens as
required by the vision prescription or in some cases the prism can be created
by the
decentration of the lens relative to the wearer's inter-pupillary distance.
[0087] Similarly, other methods of modifying the electro-active lens during
manufacture may be achieved such as by tinting the lens after surfacing, but
preferably prior to hard coating. The lens can be also made photo-chromic by
conformally coating the lens with a photo-chromic layer or a material that is
easily
imbibed with a photo-chromic dye. Alternatively, the tint may be produced by
an
electro-chromic tint created by the electro-active element or by adding
additional
layers of electro-active material to the electro-active element.
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[0088] An optional anti-reflective coating may applied to the lens, either
before or
after edging. To avoid out-gassing which may occur during application of the
anti-
reflective coating, the electro-active element should be completely sealed
within the
lens.
[0089] The present invention is not to be limited in scope by the specific
embodiments described herein. Indeed, various modifications of the present
invention, in addition to those described herein, will be apparent to those of
ordinary
skill in the art from the foregoing description and accompanying drawings.
Thus,
such modifications are intended to fall within the scope of the following
appended
claims. Further, although the present invention has been described herein in
the
context of a particular implementation in a particular environment for a
particular
purpose, those of ordinary skill in the art will recognize that its usefulness
is not
limited thereto and that the present invention can be beneficially implemented
in any
number of environments for any number of purposes. Accordingly, the claims set
forth below should be construed in view of the full breath and spirit of the
present
invention as disclosed herein.
27
