Processing of a photochromic glass for firm connection to spectacle frames for sunglasses involves applying antireflection layer on side nearest to wearer's eye and specular layer on other side

812 629 ® FRENCH REPUBLIC

NATIONAL INSTITUTE OF INDUSTRIAL PROPERTY © Publication number:

(to be used only for reproduction orders) (© national registration number

10128

PARIS © Int Cl⁷ : C 03 C 17/00, C 03 C 17/34, 17/23, G 02 B 1/11, G 02 C 7/10

A1 PATENT APPLICATION

<td>(© Date of filing: 01.08.00. ©) Priority:</td><td>(© Applicant (s): CYBEREYES Public limited company - FR.</td>

<td></td><td>@ Inventor (s): FOURQUET HENRI.</td>

<td>©) Date of availability of the request: 08.02.02 Bulletin 02/06.</td><td></td>

<td>(56) List of documents cited in the preliminary search report: See the end of this brochure</td><td></td>

<td>@) References to other related national documents:</td><td>(© Holder (s):</td>

<td></td><td>© Agent (s): CABINET BLEGER RHEIN.</td>

PROCESS FOR THE TREATMENT OF A PHOTOCHROMIC GLASS AND PHOTOCHROMIC GLASS OBTAINED BY APPLICATION OF THIS TREATMENT.

FR 2 812 629 - A1 (5 /) The invention relates to a method for treating a photochromic lens (1) intended to be made integral with the frame (2) of a pair of sunglasses (3), said photochromic lens (1) having an internal side (4) oriented in the direction of the face of the wearer of these glasses (3) and, oriented in an opposite direction, an external side (6).

This process is characterized by the fact that, on the one hand and at said internal side (4), an anti-reflective treatment of this photochromic glass (1) and, on the other hand and on the external side (6 ), to a shimmering treatment of said photochromic glass (1).

The invention also relates to a photochromic glass (1) obtained by application of such treatment.

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The present invention relates, on the one hand, to a process for treating a photochromic glass and, on the other hand, to the photochromic glass obtained through the application of this process.

This invention relates to the eyewear industry and relates, more particularly, to the field of the manufacture of lenses intended to be mounted in a spectacle frame of the solar type.

We already know a certain number of processes relating to the treatment of a photochromic glass consisting in applying a coating, consisting of at least one layer, on one of the sides of this glass.

Such a treatment leads to attenuating the transmission of light over at least part of the light spectrum, which allows the development of a protective solar glass.

The present invention aims to improve the performance of such a solar glass through the application of a new treatment to the latter.

To this end, the present invention relates to a process for treating a photochromic lens intended to be made integral with the frame of a pair of solar type limes, said photochromic lens supporting an internal side oriented in the direction of the face of the wearer. these glasses as well as, oriented in an opposite direction, an external side, characterized in that one proceeds, on the one hand and at the level of said internal side, an anti-reflection treatment of this photochromic glass and, on the other hand and on the external side, a shimmering treatment of said photochromic glass.

According to another characteristic of the present invention, the anti-reflection treatment consists in depositing, at the internal side of said photochromic glass, at least one layer of an anti-reflective material, in particular a metal oxide.

An additional characteristic relates to the fact that the anti-reflection treatment consists in depositing, successively, several layers of an anti-reflection treatment which, as the case may be

- have an equal or different thickness;

- And / or reinforce an anti-reflection material of the same or different nature.

According to an additional characteristic, the shimmering treatment consists in depositing, at said external side of said photochromic glass, at least one layer of a shimmering material.

Another characteristic consists in that a coloring of said photochromic glass is carried out by depositing at least one layer of a coloring material at the internal side of said photochromic glass.

In fact, it is preferable to color said photochromic glass before applying the anti-reflection treatment.

An additional characteristic relates to the fact that on said photochromic glass is deposited, as the case may be, at least one layer of an anti-reflection material and / or at least one layer of a shimmering material and / or at least one layer of a coloring material and that the deposition of such a layer is done by vacuum evaporation, in particular after having heated said photochromic glass.

The present invention also relates to a photochromic lens intended to be made integral with the frame of a pair of sunglasses, said photochromic lens having an internal side oriented in the direction of the face of the wearer of these glasses as well as oriented in an opposite direction, an outer side, characterized in that said photochromic glass is covered, on the one hand and at its internal side, by at least one layer of an anti-reflection material and, on the other hand and at its external side, by at least one layer of a shimmering material.

According to another characteristic, this glass comprises several layers of an anti-reflection material, these layers, as the case may be:

- having an identical or different thickness;

- And / or comprising an anti-reflection material of identical or different nature.

An additional feature is that the glass is covered, at its internal side, by at least one layer of a coloring material, in particular covered by at least one layer of an anti-reflection material.

The advantages of the present invention consist in that the treatment described above makes it possible to remarkably improve the performance of a photochromic lens, this from the point of view of the transmission of light, and, consequently, of the protection of the wearer of this glass.

Indeed, the application of such a treatment makes it possible to obtain a photochromic lens which, on the one hand and in a clear state, is in category 2 of protection and, on the other hand and at dark state, is in category 3 of protection, this from a photochromic lens which, on the one hand and in the clear state, is located in category 1 of protection and, on the other hand and to the dark state is in category 2 protection.

More specifically, after application of this treatment, there is a photochromic lens whose percentage of light transmission is covered, on the one hand and in a clear state, between 19 and 27% and, on the other hand part and in the dark state, between 8 and 12%.

Other objects and advantages of the present invention will appear during the description which follows, relating to embodiments which are given only by way of indicative and nonlimiting examples.

The understanding of this description will be facilitated by referring to the attached drawing in which:

- Figure 1 corresponds to a schematic side view of a photochromic lens according to the invention and secured to a spectacle frame;

FIG. 2 is a diagrammatic view, in section and from the side, corresponding to detail A of the glass shown in FIG. 1.

The present invention relates to the field of the eyewear industry and relates, more particularly, to the field of the manufacture of lenses intended to be mounted in a spectacle frame of the solar type.

In fact, the invention relates, more specifically, to a photochromic type glass 1 intended to be made integral with the frame 2 of a pair of sunglasses 3.

This photochromic lens 1 has, on the one hand, an internal side

4, oriented towards the face of the wearer of these glasses 3, and delimited by an internal face 5.

This photochromic lens 1 has, on the other hand and oriented in a direction opposite to the internal side 4, an external side 6 delimited by an external face 7.

The invention therefore relates to a method of treating this glass 1 characterized in that one proceeds, on the one hand and at the level of said internal side 4, to an anti-reflection treatment of this photochromic glass 1 and, d on the other hand and on the external side 6, to a shimmering treatment of said photochromic glass 1.

With regard to said anti-reflection treatment, this consists in depositing at least one layer 8, 8A of an anti-reflective material 9 at the level of the internal side 4 of said photochromic glass 1, for example, at the level of the internal face 5 of the last.

It will be observed that such an anti-reflection material 9 is preferably made up of a metal oxide.

However and according to a preferred embodiment of the present invention, the anti-reflection treatment consists in depositing, successively, several layers 8, 8A of an anti-reflection material 9.

It will be observed that very good results are obtained for two layers 8, 8A of anti-reflection material 9 as shown in FIG. 2.

It will be noted that the anti-reflection material 9 used for each of these layers 8, 8A can be, as the case may be, of the same nature or of a different nature.

For example, it is possible to deposit a first layer 8 based on a first metal oxide, in particular of the magnesium fluoride type, and a second layer 8A based on another metal oxide, in particular of the titanium dioxide type. .

Such an embodiment makes it possible to define anti-reflective layers 8, 8A having a different refractive index.

In this regard, the deposition of a layer 8 of an anti-reflection material 9, in particular a metal oxide, takes place by evaporation on said photochromic glass 1, this inside an enclosure in which it has, beforehand, an air vacuum was created.

In order to allow optimum adhesion of this anti-reflective material 9 to said glass 1, it is sometimes preferable to heat the latter, in particular to a temperature of the order of 400 ° C. Such an embodiment is particularly suitable in the case of a photochromic glass of the mineral type knowing, however, that the present invention is in no way limited thereto.

In addition, it will be observed that each of these layers 8, 8A has a determined thickness 10, 10A, which may be, as the case may be, equal or different from one layer 8 to the other 8A.

According to another characteristic of the present invention, it is also possible to determine the order and / or the thickness 10, 10A and / or the nature of the anti-reflection material 9 of the successive layers 8, 8A so that these these produce a phase opposition effect of the wavelength.

As regards the shimmering treatment, this consists of depositing, at the level of said external side 6 of the photochromic glass 1, at least one layer 11, 11A of a shimmering material 12.

It will be observed that such a deposit is made at said external side 6 of said photochromic lens 1, in particular at the level of the external face 7 of the latter.

Again, it will be noted that, in the case of a plurality of layers 11, 11Ά, the shimmering material 12 used for each of these layers 11, 11A can be, as the case may be, of the same nature or of a different nature.

The deposition of such a layer 11, 11A takes place, there again, by evaporation on said photochromic glass 1, this inside an enclosure in which the air vacuum has previously been produced.

In order to allow optimal adhesion of the shimmering material 12 to said glass 1, it is again here sometimes preferable to heat the latter.

In addition, it will be observed that, in the case of a plurality of layers 11, 11A, each of these has a determined thickness 13, 13A, which may be, as the case may be, equal or different from a layer 11 to the other 11A.

Again, it is possible to determine the order and / or the thickness 13, 13A and / or the nature of the shimmering material 12 of the successive layers 11, 11A.

According to another characteristic of the present invention, the treatment also consists in coloring said photochromic glass 1, such coloring being carried out by depositing at least one layer 14, 14A of coloring material 15 at the internal side 4 of said photochromic lens 1.

In this connection, it will be noted that such a coloring material 15 is preferably made up of a gray color or a brown color.

It will be observed that, according to a preferred embodiment of the invention, the deposition of two layers 14, 14A of a coloring material 15 makes it possible to obtain good results.

According to another characteristic and in the case of a plurality of layers 14, 14A, the coloring material 15 used for each of these layers 14, 14A can be, as the case may be, of the same color or of different color.

In addition, it will be noted that the deposition of a layer 14 of such a coloring material 15 takes place, here again, by evaporation on said photochromic glass 1, this inside a chamber in which it has, at beforehand, an air vacuum was created.

Again, it is sometimes preferable to heat the photochromic glass 1 before making such a deposit.

In the case of a plurality of layers 14, 14A, each of these 25 layers 14, 14A has a determined thickness 16, 16A, which may again be equal or different from one layer 14 to another 14A.

According to another characteristic of the present invention, it is also possible to determine the order and / or the thickness 16, 16A and / or the nature of the coloring material 15 of the successive layers 14, 14A.

Thus, the method according to the invention consists in ensuring, at the internal side 4 of the photochromic glass 1, on the one hand, an anti-reflection treatment and, on the other hand, a coloring of this photochromic glass 1.

In this regard, it should be observed that, according to a first embodiment, the anti-reflection treatment of the glass 1 is carried out before ensuring the coloring of the latter.

However and according to a preferred embodiment, one proceeds to the coloring of said photochromic glass 1 before applying the anti-reflection treatment.

To do this, it is, first of all, deposited, at the level of the internal side 4 of the photochromic glass 1, in particular at the level of the internal face 5 of the latter, at least one layer 14 of a coloring material 15.

After having ensured the coloring of this glass 1, it is ensured the deposition, over the layer or layers 14 of coloring material 15, of at least one layer 8 of an anti-reflection material 9.

Another embodiment relating to a plurality of 15 layers, as the case may be, of coloring material 15 and / or of anti-reflection material 9, consists in alternately depositing a layer 14 of a coloring material 15 with a layer 8 d 'anti-reflection material 9.

The present invention also relates to a photochromic glass 1 obtained through the application of the method described above.

Such a photochromic glass 1 is covered, on the one hand and at its internal side 4, by at least one layer 8 of an anti-reflection material 9 and, on the other hand and at its external side 6, by at least one layer 11 of a shimmering material 12.

In fact, such a glass 1 preferably comprises several layers 8, 8A of an anti-reflection material 9, these layers 8, 8A having, as the case may be, an identical or different thickness 10, 10A.

When such a glass 1 comprises several layers 8, 8A of an anti-reflection material 9, these layers 8, 8A comprise an anti-reflection material 9, as the case may be, of identical or different nature.

According to another characteristic of this glass 1, it is covered, at its internal side 4, by at least one layer 14 of a coloring material 15.

This or these layers 14 of a coloring material 15 cover or are covered by at least one layer 8 of an anti-reflection material

9.

A preferred embodiment of the present invention is given in the following description.

One such embodiment consists in carrying out, on the one hand and at the level of said external side 6, a shimmering treatment of said photochromic glass 1.

Such a shimmering treatment consists in depositing, at said external side 6 of said photochromic glass 1, in particular on its external face 7, at least one layer 11 of a shimmering material 12. Preferably this layer 11 is unique.

On the other hand and on the internal side 4, a coloring as well as an anti-reflection treatment of this photochromic glass 1.

The coloring of said glass 1 consists in depositing at least one layer 14, preferably two 14, 14A, of a coloring material 15, in particular of gray and / or brown color, this, preferably, on the internal face 5 of said photochromic glass. 1.

We then proceed to an anti-reflection treatment consisting in depositing at least one layer 8, preferably two 8, 8A, of an anti-reflection material 9, this, preferably, over the layer 14 or the layers 14, 14A of coloring material 15.

The application of such a process to a photochromic lens¹ 1 allows the latter to reach a percentage of light transmission comprised, on the one hand and in the clear state, between 19 and 27%, preferably approximately equal to 23% and, on the other hand and l 'dark state, between 8 and 12%, preferably approximately equal to 9%.

In this regard, it will be observed that the application of the only coloring treatment to said photochromic glass 1 allows the latter to achieve a percentage of light transmission which is, on the one hand and in the clear state, approximately equal to 70 % ± 4% and, on the other hand and in the dark state, approximately equal to 20% ± 2%.

Also, a photochromic lens thus colored is, on the one hand and in a clear state, in category 1 of protection and, on the other hand and in the dark state, in category 2 of protection.

The application of the anti-reflection treatment and the shimmering treatment to this colored glass makes it possible to obtain a photochromic glass which, on the one hand and in the clear state, is in category 2 of protection and, on the other hand and in the dark state, is in category 3 of protection

Although the invention has been described in connection with a particular embodiment, it is understood that it is in no way limited thereto and that it is possible to make various modifications to the forms, materials and combinations of these various elements, without departing from the scope and spirit of the invention.