Title of Invention

PROCESS FOR PRODUCING A TRANSPARENT OPTICAL ELEMENT, OPTICAL COMPONENT INVOLVED IN THIS PROCESS AND OPTICAL ELEMENT THUS OBTAINED

Abstract To produce a transparent optical element (11), one starts with producing an optical component (10) having at least one transparent array of cells (15) that are juxtaposed parallel to one surface of the component, each cell being hermetically sealed and containing a substance having an optical property. This optical component is then cut along a defined contour on its surface, corresponding to a predetermined shape of the optical element. Preferably, the array of cells constitutes a layer having a height of less than 100 µm perpendicular to the surface of the component.
Full Text

PROCESS FOR PRODUCING A TRANSPARENT OPTICAL ELEMENT,
OPTICAL COMPONENT INVOLVED IN THIS PROCESS AND OPTICAL
ELEMENT THUS OBTAINED
The present invention relates to the production of
transparent elements incorporating optical functions.
It applies especially to the production of ophthalmic
lenses having various optical properties.
Ametropia-correcting lenses are conventionally
manufactured by shaping a transparent material having a
refractive index higher than that of air. The shape of
the lenses is chosen so that the refraction at the
material/air interfaces causes suitable focussing onto
the retina of the wearer. The lens is generally cut so
as to fit into a spectacle frame, with appropriate
positioning relative to the pupil of the corrected eye.
It is known to vary the refractive index within the
material of an ophthalmic lens, thereby making it
possible to limit the geometrical constraints (see for
example EP-A-0 728 572) . This method was proposed above
all for contact lenses. The index gradient is obtained
for example by diffusion, selective irradiation or
selective heating during the manufacture of the solid
object constituting the lens. Although this provides
for manufacture for each treatable case of ametropia,
the method does not lend itself well to mass
production. Otherwise, it is possible to manufacture,
on an industrial scale, series of objects of graded
index, to select that one which is closest to the one
suitable for an eye to be corrected, and to carry out a
re-shaping operation on it, by machining and polishing,
in order to adapt it to this eye. In this case, the
need to carry out a re-shaping operation on the lenses
means that a great deal of the attraction of the method
over the conventional methods is lost.

of between 0.10 µm and 5 µm. In a first embodiment of
the invention, the walls have a thickness of between
0.10 µm and 5 µm, and preferably between 0.10 µm and
0.35 µm, so that they also produce virtually no
undesirable diffractive effects in the visible
spectrum. Such thin walls may provide a very high fill
factor τ of the optical surface with the substance
having a beneficial optical effect .
In a second embodiment, the walls have a thickness of
between 0.40 µm and 2.00 µm. For example, this
thickness may be equal to 1.00 µm. In a third
embodiment, the walls have a thickness of between
2.00 µm and 3.5 µm, it being possible for example for
this to be equal to 3.0 µm. The constituent material of
the cell walls will be chosen in such a way that the
cells will no longer be discernible from the material
with which said cells are filled. The expression "not
discernible" is understood to mean that there is no
visible scattering, no visible diffraction and no
parasitic reflections. In particular, this may be
achieved in practice by suitably adjusting the
refractive index and the absorption.
The array of cells may be formed directly on a rigid
transparent substrate, or within a flexible transparent
film that is subsequently transferred onto a rigid
transparent substrate. Said rigid transparent substrate
may be convex, concave or planar on that side which
receives the array of cells.
In one method of implementing the process, the
substance having an optical property contained in at
least some of the cells is in the form of a liquid or
gel. Said substance may especially have at least one of
the optical properties chosen from coloration,
photochromism, polarization and refractive index.
It may especially be in the form of a liquid or gel and

Patent Application US 2004/0008319 proposes to modulate
the refractive index parallel to the surface of a lens,
such as a spectacle lens, using ink-jet heads of the
kind employed in printers. These heads are controlled
so as to deposit drops of solutions of polymers having
different indices onto the surface of the object so as
to obtain the desired variation of the index over the
surface. The polymers are then solidified by
irradiation or solvent removal. Control of the physical
phenomena of interaction between the drops and the
substrate, during both deposition and solidification,
makes this method very difficult to put into practice.
Furthermore, its use on a large scale is problematic
since, here again, the index modulation is obtained
during the manufacture of the solid object constituting
the lens, and the subsequent customization assumes that
a re-shaping operation is carried out on the lens.
Another field of application of the invention is that
of photochromic lenses. The structure of such a lens
incorporates a layer whose light absorption spectrum
depends on the light received. The photochromic dye of
this layer is usually solid, although it is known that
liquids or gels have superior properties, especially in
terms of speed of reaction to the variations in
luminosity.
Nevertheless, lenses are known in which the
photosensitive dye is a liquid or a gel, spacers being
provided in the thickness of the layer in order to
define the volume occupied by the dye between adjacent
transparent layers, with an impermeable barrier around
the periphery of this volume. Such a lens is
manufactured for a specific spectacle frame. It is not
possible to cut the lens in order to fit it to another
frame. It is also difficult to adapt it to the
ametropia of a lens to be corrected.

It may also be beneficial to vary the light absorption
parallel to the surface of the lens and/or to make this
absorption dependent on the polarization of the light.
Among other types of ophthalmic lenses to which the
invention may apply, mention may be made of active
systems in which a variation in an optical property
results from an electrical stimulus. This is the case
of electrochromic lenses, or else lenses having
variable refractive properties (see for example US-A-
5 359 444 or WO 03/077012). These techniques generally
make use of liquid crystals or electrochemical systems.
Among these various types of lenses, or others that are
not necessarily limited to ophthalmic optics, it would
be desirable to be able to provide a structure that
allows one or more optical functions to be introduced
in a flexible and modular manner, while still
maintaining the possibility of cutting the optical
element obtained, with a view to incorporating it into
a specified spectacle frame or one chosen elsewhere, or
into any other means of holding said optical element in
place.
One object of the present invention is to meet this
requirement. Another object is to be able to produce
the optical element on an industrial scale under
appropriate conditions.
The invention thus proposes a process for producing a
transparent optical element, comprising the following
steps:
producing an optical component having at least
one transparent array of cells that are juxtaposed
parallel to one surface of the component, each cell
being hermetically sealed and containing a substance
having an optical property; and
cutting the optical component along a defined
contour on said surface, corresponding to a

predetermined shape of the optical element.
The cells may be filled with various substances chosen
for their optical properties, for example those
associated with their refractive index, their light
absorptivity or polarization, their response to
electrical or light stimuli, etc.
The structure therefore is adapted for many
applications, particularly those involving variable
optical functions. It implies dividing the surface of
the optical element into discrete pixels, thereby
offering great flexibility in the design, but also in
the use of the element.
In particular, it is noteworthy that the optical
component can be cut to the desired peripheral shapes,
allowing it to be incorporated and fitted to various
holding supports such as, for example, a spectacle
frame or a helmet. The process may also include,
without affecting the integrity of the structure, a
step in which the optical component is drilled so as to
fasten the optical element to its holding support.
The layer formed by the array of cells will
advantageously have a height of less than 100 µm.
According to various embodiments of the invention, this
height is preferably between 10 µm and 50 pm, or
between 1 µm and 10 µm. In particular, it may be equal
to about 5 µm.
Within the context of the invention, the array of
juxtaposed cells is preferably configured so that the
fill factor τ, defined as the area occupied by the
cells filled with the substance, per unit area of the
component, is greater than 90%. In other words, the
cells of the array occupy at least 90% of the area of
the component, at least in a region of the component
that is provided with the array of cells.

Advantageously, the fill factor is between 90% and
99.5% inclusive, and even more preferably the fill
factor is between 96% and 98.5% inclusive.
In order for the pixel structure not to cause
undesirable diffraction effects, it is possible to make
the dimensions of the cells so as to be adapted with
the wavelengths of the spectrum of the light in
question. The geometry of the array of cells is
characterized by dimensional parameters that may in
general relate to the dimensions of the cells parallel
to the surface of the optical component, to their
height corresponding to the height h of the walls
separating them, and to the thickness d of these walls,
measured parallel to the surface of the component. The
dimensions of the cells parallel to the surface define
the area σ of a cell. In the simple case where the
cells are square with sides of length D (figure 4) ,
this area is given by σ = D2, and the fill factor τ is
approximately given by D2/(D+d)2. The expressions for σ
and τ are easily obtained for any other spatial
organization of the cells.
The main source of defects in an array of cells may
consist of the grid of walls. These walls are the
source of a transparency defect of the optical
component. In the meaning of the invention, an optical
component is said to be transparent when an image
observation through this optical component is perceived
without significant contrast reduction, that is to say
when an image formation through the optical component
is obtained without impairing the image quality. Thus,
the walls which separate the optical component cells
interact with light, by diffracting this light. Within
the context of the invention, diffraction is defined as
being the light spreading phenomenon which is observed
when a luminous wave is materially bound ("Optique -

Fondement et applications" - J. P. Perez - Dunod - 7cme
edition - Paris 2004 - Page 262) . More specifically,
the light energy impinging a wall is concentrated in a
solid angle. Because of this, a light emitting point is
no longer perceived as a point through an optical
component which comprises such walls. This microscopic
diffraction appears macroscopically like diffusion.
This macroscopic diffusion, or incoherent diffusion,
appears as a milky rendering of the pixellized
structure of the optical component, and so as a
contrast reduction of an image observed through the
structure. This contrast reduction may be considered as
a transparency reduction, as defined above. Such
behaviour of macroscopic diffusion cannot be accepted
for an optical element obtained from a pixellized
optical component according to the invention, in
particular for an ophthalmic lens which has to be
transparent and should not incorporate any cosmetic
defect which could impair the vision of the wearer of
this lens. By dimensioning the cells judiciously, it is
possible to reduce the diffracted energy for a given
wavelength.
Thus, within the context of the invention, it will be
possible to give the cells dimensions of greater than
1 urn parallel to the surface of the component. In
particular, these cell dimensions parallel to the
surface of the component may be between 5 um and
100 µm. In the application to ophthalmic optics, it may
be desirable to avoid excessively large cells,
something which would give the surface of the lenses a
visible texture. Advantageously, the cells may have a
dimension of between 10 µm and 40 µm.
Parallel to the surface of the component, the cells
will preferably be separated by walls with a thickness

it may incorporate a photochromic dye, thereby making
it possible for a photochromic element with a very
rapid response to be conveniently produced.
For the application to the manufacture of corrective
lenses, it is necessary for different cells of the
optical component to contain substances having a
different refractive index. Typically, the refractive
index will be adapted so as to vary over the surface of
the component according to the estimated ametropia of
an eye to be corrected.
For the application to the manufacture of optical
lenses having a polarization optical property, the
cells of the optical component will especially contain
liquid crystals that may or may not be combined with
dyes .
One subject of the present invention is also a process
for producing an optical component as defined above,
which comprises the formation, on a substrate, of a
grid of walls for defining the cells parallel to said
surface of the component, a collective or individual
filling of the cells with the substance having an
optical property in the form of a liquid or gel, and
the closing of the cells on their opposite side from
the substrate.
The array of cells of the optical component may include
several groups of cells containing different
substances. Likewise, each cell may be filled with a
substance having one or more optical properties as
described above. It is also possible to fill several
arrays of cells over the thickness of the component. In
this embodiment, the arrays of cells may have identical
or different properties within each layer, or the cells
within each array of cells may also have different
optical properties. Thus it is possible to envisage
having a layer in which the array of cells contains a

substance for obtaining a refractive index variation
and another layer or array of cells contains a
substance having a photochromic property.
Another aspect of the invention relates to an optical
component used in the above process. This optical
component comprises at least one transparent array of
cells that are juxtaposed parallel to one surface of
the component. Each cell is hermetically sealed and
contains a substance having an optical property.
Preferably, the cells are separated by walls with a
height of less than 100 µm, advantageously less than
50 µm, and may have dimensions of greater than 1 µm
parallel to the surface of the component.
Yet another aspect of the invention relates to a
transparent optical element, especially a spectacle
lens, produced by cutting such an optical component.
Other features and advantages of the present invention
will become apparent in the description hereinbelow of
non-limiting exemplary embodiments, with reference to
the appended drawings accompanying in which:
Figure 1 is a front view of an optical
component according to the invention;
Figure 2 is a front view of an optical element
obtained from this optical component;
Figure 3 is a schematic sectional view of an
optical component according to the invention;
Figures 4 and 5 are diagrams showing two types
of lattice that can be used for arranging the cells in
an optical component according to the invention;
Figures 6 and 7 are schematic sectional views
showing this optical component at two stages of its
manufacture; and
Figure 8 is a schematic sectional view
illustrating another method of manufacturing an optical
component according to the invention.

The optical component 10 shown in Figure 1 is a blank
for a spectacle lens. A spectacle lens comprises an
ophthalmic lens. The term "ophthalmic lens" is
understood to mean a lens that is fitted to a spectacle
frame in order to protect the eye and/or correct the
sight, these lenses being chosen from afocal, unifocal,
bifocal, trifocal and varifocal lenses.
Although ophthalmic optics is the preferred field of
application of the invention, it will be understood
that this invention is applicable to transparent
optical elements of other types, such as for example
lenses for optical instruments, filters, optical sight
lenses, eye visors, optics for lightenning devices,
etc. Included within the invention in ophthalmic optics
are ophthalmic lenses, but also contact lenses and
ocular implants.
Figure 2 shows a spectacle lens 11 obtained by cutting
the blank 10 around a predefined outline, shown by the
broken line in Figure 1. In principle, this outline is
arbitrary, provided that it falls within the extent of
the blank. Mass-produced blanks can thus be used to
obtain lenses that can be adapted so as to fit a large
variety of spectacle frames. The edge of the cut lens
may be trimmed without any problem, in a conventional
manner, in order to give it a shape matched to the
spectacle frame and to the method of fastening the lens
to this spectacle frame and/or for aesthetic reasons.
It is also possible to drill holes 14 into it, for
example for receiving screws used to fasten it to the
spectacle frame.
The general shape of the blank 10 may conform to
industry standards, for example with a circular outline
of 60 mm diameter, a convex front face 12 and a concave
rear face 13 (Figure 3) . The conventional cutting,
trimming and drilling tools may thus be used to obtain
the lens 11 from the blank 10.

In Figures 1 and 2, the surface layers have been
partially cut away so as to reveal the pixellated
structure of the blank 10 and of the lens 11. This
structure consists of an array of cells or
microcavities 15 formed in a layer 17 of the
transparent component (Figure 3). In these figures, the
dimensions of this layer 17 and of the cells 15 have
been exaggerated relative to those of the blank 10 and
its substrate 16 so as to make it easier to examine the
drawing.
The lateral dimensions D of the cells 15 (parallel to
the surface of the blank 10) are greater than 1 micron
in order to avoid diffraction effects in the visible
spectrum. In practice, these dimensions are between
10 pm and 100 urn. It follows that the array of cells
can be produced using well-controlled technologies in
the field of microelectronics and micromechanical
devices.
It is therefore possible for the array of cells not to
be visible on the lens 11 or on the blank 10.
According to the invention, the height h of the layer
17 that incorporates the array of cells 15 is
preferably less than 100 pm, and more preferably
between 1 pm and 10 pm inclusive. Advantageously, this
height h is about 5 pm.
The walls 18 that separate the cells 15 ensure that
they are sealed from one another. They have a thickness
d of between 0.10 µm and 5.00 µm inclusive, in
particular making it possible to obtain a high fill
factor of the optical component. This wall thickness
may for example be equal to about 0.35 pm. A high fill
factor provides a high effectiveness of the desired
optical function provided by the substance contained in
the cells 15. This fill factor is between 90% and 99.5%

inclusive, advantageously between 96% and 98.5%
inclusive. By judiciously combining the lateral
dimension (D) of the cells with the thickness (d) and
height (h) of the walls separating the cells, it is
possible to obtain an optical component having a high
fill factor, which is not visible depending on the
optical property or properties of the substances
contained in said cells.
For example, with cells arranged in a square lattice
(Figure 4) or hexagonal lattice (Figure 5) , walls 18
with a thickness d = 2 µm and pixels of dimension
D = 100 µm, only 4% of the area is absorbing (τ ≈ 96%) .
For walls 18 with a thickness d = 1 µm and pixels of
dimension D = 40 µm (or d = 0.5 µm and D = 20 µm) , only
about 5% of the area is absorbing (τ ≈ 95%) . The lower
limit may be about τ = 90%.
The honeycomb or hexagonal-type lattice, shown in
Figure 5, is a preferred arrangement as it optimizes
the mechanical strength of the array of cells for a
given aspect ratio. However, within the context of the
invention all possible lattice arrangements complying
with a crystal geometry are conceivable. Thus, a
lattice of rectangular, triangular or octagonal
geometry can be produced. Within the context of the
invention, it is also possible to have a combination of
various geometrical lattice shapes in order to form the
array of cells, while still respecting the dimensions
of the cells as defined above.
The layer 17 incorporating the array of cells 15 may be
covered with a number of additional layers 19, 20
(Figure 3) , as is usual in ophthalmic optics. These
layers provide, for example, such functions as impact
resistance, scratch resistance, coloration,
antireflection, antisoiling, etc. In the example shown,
the layer 17 incorporating the array of cells is placed
immediately on top of the transparent substrate 16, but

it will be understood that one or more intermediate
layers may be placed between them, such as layers
providing impact resistance, scratch resistance or
coloration functions.
Moreover, it is possible for several arrays of cells to
be present in the multilayer stack formed on the
substrate. It is thus possible, for example, for the
multilayer stack to include, in particular, a layer
incorporating arrays of cells containing a substance
allowing the element to be provided with photochromic
functions and another layer allowing the element to be
provided with refractive-index-variation functions.
These layers incorporating arrays of cells may also be
alternated with additional layers as described above.
The various combinations are possible thanks in
particular to the great flexibility of the process for
producing the transparent optical element. Thus, within
the context of the invention, the optical component may
include an array of cells in which each cell is filled
with a substance having one or more optical properties,
or else in which the array of cells 15 includes several
groups of cells containing different substances. The
optical component may also consist of a stack
comprising at least two layers incorporating an array
of cells, each array of cells having identical optical
properties, or each array of cells having different
optical properties, or the cells within each array of
cells having different optical properties.
The transparent substrate 16 may be made of glass or
various polymer materials commonly used in ophthalmic
optics. Among the polymer materials which can be used,
one can cite, for information but in a non-limitating
purpose, polycarbonate materials, polyamides,
polyimides, polysulfons, copolymers of
polyethylenterephtalate and polycarbonate, polyolefins,
in particular polynorbornens, polymers and copolymers

of diethylen glycol di(allylcarbonate), (meth)acrylic
polymers and copolymers, in particular (meth)acrylic
polymers and copolymers derived from A-bisphonol,
thio(meth)acrylic polymers and copolymers, urethane and
thiourethane polymers and copolymers, epoxy polymers
and copolymers, and episulfide polymers and copolymers.
The layer 17 incorporating the array of cells is
preferably located on its convex front face 12, the
concave rear face 13 remaining free in order to undergo
any re-shaping operation, by machining and polishing,
should this be necessary. However, if the transparent
optical element is a corrective lens, the ametropia
correction may be achieved by spatially varying the
refractive index of the substances contained in the
cells 15, which makes it possible to dispense with any
rework on the rear face, and consequently providing
greater flexibility in the design and/or the
implementation of the various layers and coatings with
which the lens has to be provided. The optical
component may also be located on the concave face of a
lens. Of course, the optical component may also be
incorporated onto a plane optical element.
Figures 6 and 7 illustrate a first way in which the
array of cells is produced on the substrate 16. The
technique here is similar to those used for
manufacturing electrophoretic display devices. Such
techniques are described for example in documents
WO 00/77570, WO 02/01281, US 2002/0176963, US 6 327 072
or US 6 597 340. The array of cells can also be
produced using fabrication processes deriving from
microlectronics, well-known to those skilled in the
art. By way of non-limiting illustration, mention may
be made of the processes such as hot printing, hot
embossing, photolithography, (hard, soft, positive or
negative), microdeposition, such as microcontact
printing, screen printing, or else ink-jet printing.

In the example in question, a film of a solution of
radiation-curable, for example UV-curable, monomers is
deposited at first on the substrate 16. This film is
exposed to ultraviolet radiation through a mask, which
masks off the squares or hexagons distributed in a
lattice and corresponding to the positions of the
microcavities 15. By selective curing, the walls 18
standing up on top of a support layer 21 are left in
place. The monomer solution is then removed and the
component is in the state shown in Figure 6.
To obtain a similar structure, another possibility is
to use a photolithography technique. This starts with
the deposition on the substrate 16 of a layer of
material, for example a polymer, with a thickness of
the order of the intended height for the walls 18, for
example 5 µm or 20 µm. Next, a film of a photoresist is
deposited on this layer, this film being exposed
through a mask in the form of a grid pattern. The
unexposed regions are removed upon developing the
photoresist, in order to leave a mask aligned with
respect to the positions of the walls, through which
the layer of material is subjected to anisotropic
etching. This etching, which forms the microcavities
15, is continued down to the desired depth, after which
the mask is removed by chemical etching.
Starting from the state shown in Figure 6, the
microcavities 15 are filled with the substance having
an optical property, in the liquid or gel state. A
prior treatment of the front face of the component may
optionally be applied in order to facilitate the
surface wetting of the material of the walls and of the
bottom of the microcavities. The solution or suspension
forming the substance with an optical property may be
the same for all the microcavities of the array, in
which case it may be introduced simply by dipping the
component into a suitable bath, using a process of the
screen-printing type, a spin coating process, a process

in which the substance is spread using a roller or a
doctor blade, or else a spray process. It is also
possible to inject it locally into the individual
microcavities using an ink-jet head.
The latter technique will typically be adopted when the
substance with an optical property differs from one
microcavity to another, several ink-jet heads being
moved over the surface in order to fill the
microcavities in succession.
However, especially in the case in which the
microcavities are formed by selective etching, another
possibility is to hollow out at first a group of
microcavities, to collectively fill them with a first
substance, and then to close them off, the rest of the
surface of the component remaining masked during these
operations. Next, the selective etching is repeated
through a resist mask covering at least the regions of
microcavities that have already been filled, in
addition to the wall regions, and the new microcavities
are filled with a different substance and then closed
off. This process may be repeated one or more times if
it is desired to distribute different substances over
the surface of the component.
To hermetically seal an array of filled microcavities,
an adhesive-coated plastic film is for example applied,
this being thermally welded or hot-laminated onto the
top of the walls 18. It is also possible to deposit
onto the region to be closed off a curable material in
solution, this material being immiscible with the
substance having an optical property contained in the
microcavities, and then to cure this material, for
example using heat or irradiation.
Once the array of microcavities 15 has been completed
(Figure 7), the component may receive the additional
layers or coatings 19, 20 in order to complete its

manufacture. Components of this type are mass produced
and then stored, to be taken up again later and
individually cut according to the requirements of a
customer.
If the substance having an optical property is not
intended to remain in the liquid or gel state, a
solidification treatment may be applied to it, for
example a heating and/or irradiation sequence, at an
appropriate stage after the moment when the substance
has been deposited.
In a variant shown in Figure 8, the optical component
consisting of an array of microcavities 25 is
constructed in the form of a flexible transparent film
27. Such a film 27 can be produced by techniques
similar to those described above. In this case, the
film 27 can be produced on a planar substrate, i.e. one
that is not convex or concave.
The film 27 is for example manufactured on an
industrial scale, with a relatively large size, in
order to make savings in the combined execution of the
steps of the process, and then it is cut to the
appropriate dimensions in order to be transferred onto
the substrate 16 of a blank. This transfer may be
carried out by adhesively bonding the flexible film, by
thermoforming the film, or even by a physical adhesion
effect in a vacuum. The film 27 may then receive
various coatings, as in the previous case, or may be
transferred onto the substrate 16 which is itself
coated with one or more additional layers as described
above.
In one field of application of the invention, the
optical property of the substance introduced into the
microcavities 15 is its refractive index. The
refractive index of the substance is varied over the
surface of the component in order to obtain a

corrective lens. In a first embodiment of the
invention, the variation may be produced by introducing
substances of different indices during the manufacture
of the array of microcavities 15.
In another embodiment of the invention, the variation
may be achieved by introducing into the microcavities
15 a substance whose refractive index may be
subsequently adjusted by irradiation. The writing of
the corrective optical function is then carried out by
exposing the blank 10 or the lens 11 to light whose
energy varies over the surface in order to obtain the
desired index profile, so as to correct the vision of a
patient. This light is typically that produced by a
laser, the writing equipment being similar to that used
for etching CD-ROMs or other optical memory media. The
greater or lesser exposure of the photosensitive
substance may result from a variation in the power of
the laser and/or of the choice of the exposure time.
Among the substances that can be used in this
application, mention may be made, for example, of
mesoporous materials and liquid crystals. The liquid
crystals may be frozen by a polymerization reaction,
for example one induced by irradiation. Thus, they may
be frozen in a chosen state in order to introduce a
predetermined optical retardation in the lightwaves
that pass through them. In the case of a mesoporous
material, the refractive index of the material is
controlled through the variation in its porosity.
Another possibility is to use photopolymers that have
the well-known property of changing its refractive
index over the course of the irradiation-induced curing
reaction. These index changes are due to a modification
of the density of the material and to a change in the
chemical structure. It will be preferable to use
photopolymers that undergo only a very small volume
change during the polymerization reaction.

The selective polymerization of the solution or
suspension is carried out in the presence of radiation
that is spatially differentiated with respect to the
surface of the component, so as to obtain the desired
index variation. This variation is determined
beforehand according to the estimated ametropia of a
patient's eye to be corrected.
In another application of the invention, the substance
introduced in liquid or gel form into the microcavities
has a photochromic property. Among the substances used
in this application, mention may be made, by way of
examples, of photochromic compounds containing a
central unit such as a spirooxazine, spiro-indoline-
[2,3']benzoxazine, chromene, spiroxazine homoazaadaman-
tane, spirofluorene-{2H)-benzopyrane or naphtho[2,1-b]-
pyrane core such as those described in particular in
the Patents and Patent Applications FR 2 763 070, EP 0
676 401, EP 0 489 655, EP 0 653 428, EP 0 407 237, FR 2
718 447, US 6 281 366 and EP 1 204 714.
Within the context of the invention, the substance
having an optical property may also be a dye, or a
pigment capable of modifying the degree of
transmission.

WE CLAIM :
1. Process for producing a transparent optical element (11), comprising the
steps of:
- producing an optical component (10) having at least one transparent array of
cells (15; 25) that are juxtaposed parallel to a surface of the component,
each cell being hermetically sealed and containing a substance having an
optical property; and
- cutting the optical component (10) along a contour defined on said surface,
corresponding to a predetermined shape for the optical element (11),
characterized in that the set of cells (15; 25) comprises several groups of
cells containing different substances.

2. Process as claimed in claim 1, wherein the set of cells constitutes a layer
having, perpendicular to said surface, a height of less than 100 µm.
3. Process as claimed in claim 2, wherein the layer formed by the set of cells
has a height of between 10 µm and 50 µm.
4. Process as claimed in claim 2, wherein the layer formed by the set of cells
has a height of between 1 µm and 10 µm.
5. Process as claimed in claim 4, wherein the layer formed by the set of cells
has a height of about 5 µm.

6. Process as claimed in any one of the preceding claims, which furthermore
comprises a step of drilling through the optical component (10) in order to
fasten the optical element (11) to a holding support.
7. Process as claimed in one of the preceding claims, wherein the production of
the optical component (10) comprises the formation of the set of cells (15)
on a rigid transparent substrate (16).
8. Process as claimed in one of the preceding claims, wherein the production of
the optical component (10) comprises the formation of the set of cells (25)
within a flexible transparent film (27) followed by the transfer of said film
onto a rigid transparent substrate (16).
9. Process as claimed in claim 7 or 8, wherein the rigid transparent substrate
(16) is convex, concave or planar on that side which receives the set of cells
(15; 25).
10. Process as claimed in any one of the preceding claims, wherein the substance
having an optical property contained in at least some of the cells (15; 25) is
in the form of a liquid or gel.
11. Process as claimed in claim 10, wherein the production of the optical
component (10) comprises the formation, on a substrate, of a network of
walls (18) for defining the cells (15) parallel to said surface of the
component, the collective or individual filling of the cells with the substance
having an optical property in the form of a liquid or gel, and the closing of
the cells on their side opposite from the substrate.

12. Process as claimed in any one of the preceding claims, wherein the optical
property is selected from a coloration, photochromism, polarization or
refractive-index property.
13. Process as claimed in any one of the preceding claims, wherein different cells
(15; 25) contain substances having a different refractive index.
14. Process as claimed in claim 13, wherein the substances having a different
refractive index comprise photopolymers, liquid crystals or mesoporous
materials.
15. Process as claimed in claim 14, wherein the production of the optical
component (10) comprises the formation, on a substrate (16), of a network
of walls (18) for defining the cells (15) parallel to said surface of the
component, the collective filling of the cells with a solution or a suspension of
monomers or liquid crystals, the closing of the cells on their side opposite
from the substrate, and the selective curing of said solution or suspension in
the presence of electromagnetic radiation differentiated parallel to said
surface of the component.

16. Process as claimed in any one of claims 13 to 15, wherein the refractive
index of the substances contained in the cells are adapted in order to vary
said index over the surface of the component according to the estimated
ametropia of an eye to be corrected.
17. Process as claimed in any one of the preceding claims, wherein the
production of the optical component (10) comprises the formation, on a
substrate (16), of a network of walls (18) for defining the cells (15) parallel to
said surface of the component, a differentiated filling of the cells with the
substances having an optical property, using ink-jet heads, and the closing of
the cells on their side opposite from the substrate.
18. Process as claimed in any one of the preceding claims, wherein several sets
of cells are stacked on the thickness of the component.
19. Process as claimed in claim 18, wherein each set of cells has identical optical
properties, or each set of cells has different optical properties, or the cells
within each set of cells have different optical properties.
20. Process as claimed in any one of the preceding claims, wherein the fill factor
τ is greater than 90%, parallel to the surface of the component.
21. Process as claimed in claim 20, wherein the fill factor is between 90% and
99.5% inclusive.

22. Process as claimed in claim 21, wherein the fill factor is between 96% and
98.5%.
23. Process as claimed in any one of the preceding claims, wherein the cells (15;
25) of the set are arranged in a hexagonal-type lattice.
24. Process as claimed in any one of the preceding claims, wherein the cells (15;
25) have dimensions of greater than 1 µm parallel to the surface of the
component.
25. Process as claimed in claim 24, wherein the cells (15; 25) have a dimension
of between 5 µm and 100 µm parallel to the surface of the component.
26. Process as claimed in claim 25, wherein the cells (15; 25) have a dimension
of between 10 µm and 40 µm parallel to the surface of the component.
27. Process as claimed in any one of the preceding claims, wherein the cells (15;
25) are separated by walls (18) having dimensions of between 0.10 µm and 5
µm parallel to the surface of the component.

28. Process as claimed in claim 27, wherein the walls (18) have dimensions of
less than 0.35 µm.
29. Process as claimed in claim 27, wherein the cells (15; 25) are separated by
walls (18) made of a material that does not reflect light and have dimensions
of between 0.40 µm and 3.00 µm.
30. Process as claimed in claim 29, wherein the walls have dimensions of
between 0.40 µm and 1.00 µm.



ABSTRACT


PROCESS FOR PRODUCING A TRANSPARENT OPTICAL
ELEMENT, OPTICAL COMPONENT INVOLVED
IN THIS PROCESS AND OPTICAL ELEMENT
THUS OBAINED.
To produce a transparent optical element (11), one starts with producing an
optical component (10) having at least one transparent array of cells (15)
that are juxtaposed parallel to one surface of the component, each cell being
hermetically sealed and containing a substance having an optical property.
This optical component is then cut along a defined contour on its surface,
corresponding to a predetermined shape of the optical element. Preferably,
the array of cells constitutes a layer having a height of less than 100 µm
perpendicular to the surface of the component.

Documents:

03680-kolnp-2006 abstract.pdf

03680-kolnp-2006 claims.pdf

03680-kolnp-2006 correspondence others.pdf

03680-kolnp-2006 description(complete).pdf

03680-kolnp-2006 drawings.pdf

03680-kolnp-2006 form1.pdf

03680-kolnp-2006 form2.pdf

03680-kolnp-2006 form3.pdf

03680-kolnp-2006 form5.pdf

03680-kolnp-2006 international publication.pdf

03680-kolnp-2006 international search authority report.pdf

03680-kolnp-2006 prioroty document.pdf

03680-kolnp-2006-correspondence others-1.1.pdf

03680-kolnp-2006-priority document-1.1.pdf

3680-KOLNP-2006-(03-01-2012)-ABSTRACT.pdf

3680-KOLNP-2006-(03-01-2012)-AMANDED CLAIMS.pdf

3680-KOLNP-2006-(03-01-2012)-CORRESPONDENCE.pdf

3680-KOLNP-2006-(03-01-2012)-DESCRIPTION (COMPLETE).pdf

3680-KOLNP-2006-(03-01-2012)-EXAMINATION REPORT REPLY RECEIVED.pdf

3680-KOLNP-2006-(03-01-2012)-FORM-1.pdf

3680-KOLNP-2006-(03-01-2012)-FORM-2.pdf

3680-KOLNP-2006-(03-01-2012)-FORM-3.pdf

3680-KOLNP-2006-(03-01-2012)-FORM-5.pdf

3680-KOLNP-2006-(03-01-2012)-OTHER PATENT DOCUMENT.pdf

3680-KOLNP-2006-(03-01-2012)-OTHERS.pdf

3680-KOLNP-2006-(03-08-2012)-CORRESPONDENCE.pdf

3680-KOLNP-2006-(09-10-2012)-CLAIMS.pdf

3680-KOLNP-2006-(09-10-2012)-CORRESPONDENCE.pdf

3680-KOLNP-2006-CANCELLED PAGES.pdf

3680-KOLNP-2006-CORRESPONDENCE.pdf

3680-KOLNP-2006-EXAMINATION REPORT.pdf

3680-kolnp-2006-form 18.pdf

3680-KOLNP-2006-FORM 26.pdf

3680-KOLNP-2006-GRANTED-ABSTRACT.pdf

3680-KOLNP-2006-GRANTED-CLAIMS.pdf

3680-KOLNP-2006-GRANTED-DESCRIPTION (COMPLETE).pdf

3680-KOLNP-2006-GRANTED-DRAWINGS.pdf

3680-KOLNP-2006-GRANTED-FORM 1.pdf

3680-KOLNP-2006-GRANTED-FORM 2.pdf

3680-KOLNP-2006-GRANTED-FORM 3.pdf

3680-KOLNP-2006-GRANTED-FORM 5.pdf

3680-KOLNP-2006-GRANTED-SPECIFICATION-COMPLETE.pdf

3680-KOLNP-2006-OTHERS.pdf

3680-KOLNP-2006-PETITION UNDER RULE 137.pdf

3680-KOLNP-2006-REPLY TO EXAMINATION REPORT.pdf

3680-KOLNP-2006-TRANSLATED COPY OF PRIORITY DOCUMENT.pdf

abstract-03680-kolnp-2006.jpg


Patent Number 257763
Indian Patent Application Number 3680/KOLNP/2006
PG Journal Number 44/2013
Publication Date 01-Nov-2013
Grant Date 31-Oct-2013
Date of Filing 07-Dec-2006
Name of Patentee ESSILOR INTERNATIONAL(COMPAGNIE GENERALE D'OPTIQUE)
Applicant Address 147 RUE DE PARIS, 94220 CHARENTON LE PONT, FRANCE
Inventors:
# Inventor's Name Inventor's Address
1 CANO JEAN-PAUL C/O ESSILOR INTERNATIONAL(COMPAGNIE GENERALE D'OPTIQUE), 147 RUE DE PARIS, 94220 CHARENTON LE PONT, FRANCE
2 BOVET CHRISTIAN C/O ESSILOR INTERNATIONAL(COMPAGNIE GENERALE D'OPTIQUE), 147 RUE DE PARIS, 94220 CHARENTON LE PONT, FRANCE
PCT International Classification Number G02C7/08; G02C7/10
PCT International Application Number PCT/FR2005/001610
PCT International Filing date 2005-06-24
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 0407387 2004-07-02 France
2 0413537 2004-12-17 France