CA2093281A1 - Lens for eyeglasses - Google Patents
Lens for eyeglassesInfo
- Publication number
- CA2093281A1 CA2093281A1 CA002093281A CA2093281A CA2093281A1 CA 2093281 A1 CA2093281 A1 CA 2093281A1 CA 002093281 A CA002093281 A CA 002093281A CA 2093281 A CA2093281 A CA 2093281A CA 2093281 A1 CA2093281 A1 CA 2093281A1
- Authority
- CA
- Canada
- Prior art keywords
- lens
- lenses
- composite plastic
- eyeglass
- composite
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B1/00—Optical elements characterised by the material of which they are made; Optical coatings for optical elements
- G02B1/04—Optical elements characterised by the material of which they are made; Optical coatings for optical elements made of organic materials, e.g. plastics
- G02B1/041—Lenses
-
- G—PHYSICS
- G02—OPTICS
- G02C—SPECTACLES; SUNGLASSES OR GOGGLES INSOFAR AS THEY HAVE THE SAME FEATURES AS SPECTACLES; CONTACT LENSES
- G02C7/00—Optical parts
- G02C7/02—Lenses; Lens systems ; Methods of designing lenses
Landscapes
- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Ophthalmology & Optometry (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- General Health & Medical Sciences (AREA)
- Eyeglasses (AREA)
- Laminated Bodies (AREA)
Abstract
LENS FOR EYEGLASSES
ABSTRACT
A composite plastic eyeglass lens comprised of a front lens located on an object side of the eyeglass lens, and a rear lens located on a user's eye side of the eyeglass lens, wherein the rear lens is made of polycarbonate resin or polyurethane resin.
ABSTRACT
A composite plastic eyeglass lens comprised of a front lens located on an object side of the eyeglass lens, and a rear lens located on a user's eye side of the eyeglass lens, wherein the rear lens is made of polycarbonate resin or polyurethane resin.
Description
LENS FOR EYEGLASSES
BACKGROUND OF THE INVENTION
1. Field of the Invention The present invention relates to lenses for eyeglasses or spectacles comprised of a pair of plastic lenses.
BACKGROUND OF THE INVENTION
1. Field of the Invention The present invention relates to lenses for eyeglasses or spectacles comprised of a pair of plastic lenses.
2. Description of Related Art Expensive lenses for eyeglasses (i.e. eyeglass or spectacle lenses), such as multi-focus or progressive multi-focus lenses, have been made by adhering a pair of plastic lenses into a plastic composite lens. The provision of such eyeglass or spectacle lenses is made possible by the use of plastic lenses which can be independently designed with a great degree of freedom.
Such an eyeglass lens consists of a front lens, which is located on an object side of the eyeglass lens, and a rear lens, which is located on the user's eye side of the eyeglass lens. In known plastic composite lenses, the front lens and the rear lens are usually made of diethyleneglycolbisallylcarbonate polymer (CR-39plastic).
Known plastic composite lenses, however, have drawbacks as discussed below.
Firstly, the impact resistance of such lenses is low. In particular, some plastic composite lenses having a small center thickness do not meet the requirements prescribed in the drop-ball test (i.e., crushing ball test) ` .
' :' ' ' ~ ' 209~2~1 -standardized by the U.S. FDA (U.S. Food & Drug Administration). In the drop-ball test, used in a sampling inspection, a steel ball having a weight of 16g is dropped from a height of 127 cm onto the center of a lens. Only the lenses corresponding to the test samples that are not destroyed or crushed by the steel ball aEe authorized by the FDA. In the case of lenses having a thickness at the center of around 1.5 mm, the rear lens tends to shatter before the front lens. From a safety standpoint, this is an unacceptable result.
Secondly, there is a large difference in thickness between the center portion and the edge portion of either the front or rear lens. This results in a significant difference in polymerization shrinkage between the center portion and the edge portion of the front or rear lens particularly in high negative power lenses.
Consequently, during the molding operation, the lens can easily become separated from the molding die, resulting in a decreased yield.
A feature of one embodiment of the present invention is to provide a strong composite eyeglass or spectacle lens consisting of a front and rear lens.
Another feature of an embodiment of the present invention is to provide a thin and light composite eyeglass or spectacle lens.
.
2as32si SUMMARY OF THE INVENTION
The inventors of the present invention have focused on the plastic material of which the front and rear lenses of a composite eyeglass or spectacle lens are made.
They have found that by making the rear lens on the user's eye side out of polycarbonate resin or polyurethane resin, rather than the conventional diethyleneglycol bisallylcarbonate polymer, a strong, thin, and light plastic composite eyeglass lens can be realized.
In accordance with an embodiment of the present invention there is provided a composite plastic eyeglass lens comprised of a front lens located on an object side of the eyeglass lens, and a rear lens located on a user's eye side of the eyeglass lens, wherein the rear lens is made of polycarbonate resin or polyurethane resin.
Polycarbonate resin or polyurethane resin has a greater mechanical strength and a higher refractive index than that of diethyleneglycol bisallylcarbonate polymer.
~- Accordingly, a composite plastic eyeglass lens made of polycarbonate resin or polyurethane resin will have a ` greater mechanical strength than the conventional composite lens. Consequently, a lens that is relatively thin at the center can satisfy the requirements prescribed in the drop-ball test mentioned above.
Furthermore, a thinner lens having the same power as that of the conventional composite plastic lens can be realized, owing to the high refractive index.
A thinner lens is particularly advantageous in the case of a rear lens on the user's eye side which has a negative (i.e. minus) power. The thickness of a negative power lens at the edge thereof increases as the power increases, resulting in an increase in thickness of the spectacle or eyeglass lens as a whole. The thickness of the eyeglass lens can be reduced if the rear lens is made of a material having a high refractive index, since the edge thickness of the rear lens is reduced. Namely, the thickness of the composite plastic lens can be reduced on the whole without decreasing the mechanical strength thereof.
The front lens on the object side is preferably made of diethyleneglycol bisallylcarbonate polymer, similar to the conventional product. This is in view of the molding process. Namely, diethyleneglycol bisallylcarbonate polymer can be precisely molded by a glass molding die due to thermal polymerization of the plastic. In general, the surface of the front lens has a curvature which is designed to give the composite lens multi-focus or progressive multi-focus characteristics and is sometimes defined by an aspheric surface. Consequently, ; it is necessary to precisely mold the front lens.
Polycarbonate resin or polyurethane resin can be molded in a predetermined shape by an injection molding process. Injection molding of such resins does not yield a lens having a shape as precise as the lens made by the ~ . .' ~ -.
molding of diethyleneglycol bisallylcarbonate polymer in the glass molding die. However, the shape of the rear lens is simpler than that of the front lens. Accordingly, in the preparation of the rear lens, the simpler injection molding process will suffice.
Moreover, the percentage of shrinkage of polycarbonate resin or polyurethane resin is usually about 8%. This is considerably less than that of diethyleneglycol bisallylcarbonate polymer which has a percentage of shrinkage of about 12%. Consequently, the percentage of defective molded lenses that are produced is decreased, resulting in an increased yield of rear lenses, and accordingly, an increased yield of the composite plastic eyeglass lenses as a whole.
As can be seen from the above discussion, according to the present invention, the front lens, which usually has a complex shape that must be precisely molded in accordance with the desired multi-focus, progressive multi-focus, or aspheric surface characteristics, is made of diethyleneglycol bisallylcarbonate polymer. Conjointly, the rear lens, which is usually simpler in shape than the front lens, is made of polyurethane resin or polycarbonate resin having the necessary degree of mechanical strength.
The separate functions of the front lens and rear lens also contribute to an increase in the freedom of design thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be described below in detail with ;:
:
reference to the accompanying drawings, in which:
Fig. 1 is a sectional view of a composite eyeglass lens according to the present invention;
Fig. 2 is a schematic sectional view of a molding die which is used to mold a front plastic lens of a composite eyeglass lens located on an object side thereof, according to the present invention; and, Fig. 3 is a schematic sectional view of a molding die which is used to mold a rear plastic lens of a composite eyeglass lens located on a user's eye side thereof, according to the present invention.
.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In Fig. 1, a composite eyeglass lens 11 according to the present invention is comprised of a pair of plastic lenses, i.e., a front lens 12 on an object side and a rear lens 13 on a user's eye side thereof. In the illustrated embodiment, the composite eyeglass lens 11 has a negative power as a whole. The front lens 12 is made of diethyleneglycol bisallylcarbonate polymer (CR-39, n=1.5, ; ~ =55) and has a positive power. The rear lens 13 is made of polycarbonate resin (n=1.58, ~ =29) and has a negative power.
To mold the front lens 12, a molding cavity 24 de~ined by upper and lower lens molding dies 21 and 22, and gaskets 23 is filled with diethyleneglycol , ~ . . , , - ~' ~' :~
.
bisallylcarbonate polymer, as shown in Fig. 2. The front lens 12 can be molded by thermal polymerization of diethyleneglycol bisallylcarbonate polymer per se known.
On the other hand, the rear lens 13 is molded by injection molding polycarbonate resin in an injection molding cavity 27 defined by upper and lower molding dies 25 and 26, as shown in Fig. 3.
The mating surfaces 12a and 13a (defined by the molding surfaces of the lower molding die 22 and the upper molding die 25) of the front lens 12 and the rear lens 13 are identical in shape. The molded front lens 12 and the injection-molded rear lens 13 are adhered to each other at the mating surfaces 12a and 13a by, for example, a W
setting adhesive 14 ~Fig. 1) to form a composite plastic eyeglass lens 11 comprised of the front and rear lenses.
Since the rear lens 13 is made of polycarbonate resin having a large refractive index n, the thickness, particularly the thickness at the edge thereof, can be reduced in comparison with the conventional rear lens which is made of diethyleneglycol bisallylcarbonate polymer. The conventional rear lens made of diethyleneglycol bisallylcarbonate polymer is designated at a phantom line in Fig. 1. Consequently, the overall thickness and the edge thickness of the composite eyeglass lens 11, according to the present invention, is less than that of the -:
j: :
2~9328~
conventional composite eyeglass lens, resulting in a good appearance thereof.
Furthermore, the rear lens 13 provides sufficient mechanical strength for the eyeglass lens. In spite of the thin center portion thereof, the lens will not be destroyed or crushed by a steel ball in the drop-ball test.
Two examples of products (i.e., composite plastic eyeglass lenses) are shown below.
Example 1 Four rear lenses made of CR-39, polycarbonate resin, polyurethane resin 1, and polyurethane resin 2 were prepared. Numerical data of the four rear lenses is shown in Table 1 below , .
, : :
:
, .
.
2~93281 Table lens (dioptric) power(D) 5-3.40 5-3.40 5-3.40 5-3.40 refractive index 1.50 1.58 1.60 1.66 ..
first surface R (mm) 93.62 93.62 93.62 93.62 - ............................ _.
second surface R (mm~ 57.10460.32461.041 63.014 _ center thickness (mm) 0.8 0.8 0.8 0.8 edge thickness (mm) 7 0 6.0 S 54 5 33 ;
wherein, S represents a spherical lens surface;
PC represents polycarbonate;
PU 1 represents polyurethane 1; and, PU 2 represents polyurethane 2 In Table 1, the first surface R designates the radius (mm) of the mating lens surface 13a of the rear lens 13 -.
which is connected to the mating surface 12a of the front lens 12. The second surface R designates the radius (mm) of the lens surface of the rear lens 13 opposite the mating surface 13a.
As can be seen from Table 1, since the rear lens made of polycarbonate resin or polyurethane resin has a refractive index larger than that of the rear lens made of CR-39, it is possible to increase the radius R of the second surface to reduce the edge thickness thereof.
Example 2 Four rear lenses made of CR-39, polycarbonate resin, polyurethane resin 1, and polyurethane resin 2 were prepared, similar to Example 1 above. In Example 2, however, the four lenses are identical in shape. Namely, the radii R of the first and second surfaces are 93.62 mm and 57.104 mm, respectively, the center thickness 0.8 mm, and the edge thickness 7.0 mm. The lens degrees of the four lenses are shown in Table 2 below.
Table 2 ~IPU 1 _ lens power (D) 5-3.40 5-3.94 S-4.078 S-4.484 , -, ~
.
, . .
- :~
, .
20~3281 wherein, S represents a spherical power PC represents polycarbonate;
s PU 1 represents polyurethane 1; and, PU 2 represents polyurethane 2 As can be seen from Table 2, as long as the lenses have the same shape, the lens made of polycarbonate or polyurethane has a lens degree higher than that of the lens made of CR-39.
'
Such an eyeglass lens consists of a front lens, which is located on an object side of the eyeglass lens, and a rear lens, which is located on the user's eye side of the eyeglass lens. In known plastic composite lenses, the front lens and the rear lens are usually made of diethyleneglycolbisallylcarbonate polymer (CR-39plastic).
Known plastic composite lenses, however, have drawbacks as discussed below.
Firstly, the impact resistance of such lenses is low. In particular, some plastic composite lenses having a small center thickness do not meet the requirements prescribed in the drop-ball test (i.e., crushing ball test) ` .
' :' ' ' ~ ' 209~2~1 -standardized by the U.S. FDA (U.S. Food & Drug Administration). In the drop-ball test, used in a sampling inspection, a steel ball having a weight of 16g is dropped from a height of 127 cm onto the center of a lens. Only the lenses corresponding to the test samples that are not destroyed or crushed by the steel ball aEe authorized by the FDA. In the case of lenses having a thickness at the center of around 1.5 mm, the rear lens tends to shatter before the front lens. From a safety standpoint, this is an unacceptable result.
Secondly, there is a large difference in thickness between the center portion and the edge portion of either the front or rear lens. This results in a significant difference in polymerization shrinkage between the center portion and the edge portion of the front or rear lens particularly in high negative power lenses.
Consequently, during the molding operation, the lens can easily become separated from the molding die, resulting in a decreased yield.
A feature of one embodiment of the present invention is to provide a strong composite eyeglass or spectacle lens consisting of a front and rear lens.
Another feature of an embodiment of the present invention is to provide a thin and light composite eyeglass or spectacle lens.
.
2as32si SUMMARY OF THE INVENTION
The inventors of the present invention have focused on the plastic material of which the front and rear lenses of a composite eyeglass or spectacle lens are made.
They have found that by making the rear lens on the user's eye side out of polycarbonate resin or polyurethane resin, rather than the conventional diethyleneglycol bisallylcarbonate polymer, a strong, thin, and light plastic composite eyeglass lens can be realized.
In accordance with an embodiment of the present invention there is provided a composite plastic eyeglass lens comprised of a front lens located on an object side of the eyeglass lens, and a rear lens located on a user's eye side of the eyeglass lens, wherein the rear lens is made of polycarbonate resin or polyurethane resin.
Polycarbonate resin or polyurethane resin has a greater mechanical strength and a higher refractive index than that of diethyleneglycol bisallylcarbonate polymer.
~- Accordingly, a composite plastic eyeglass lens made of polycarbonate resin or polyurethane resin will have a ` greater mechanical strength than the conventional composite lens. Consequently, a lens that is relatively thin at the center can satisfy the requirements prescribed in the drop-ball test mentioned above.
Furthermore, a thinner lens having the same power as that of the conventional composite plastic lens can be realized, owing to the high refractive index.
A thinner lens is particularly advantageous in the case of a rear lens on the user's eye side which has a negative (i.e. minus) power. The thickness of a negative power lens at the edge thereof increases as the power increases, resulting in an increase in thickness of the spectacle or eyeglass lens as a whole. The thickness of the eyeglass lens can be reduced if the rear lens is made of a material having a high refractive index, since the edge thickness of the rear lens is reduced. Namely, the thickness of the composite plastic lens can be reduced on the whole without decreasing the mechanical strength thereof.
The front lens on the object side is preferably made of diethyleneglycol bisallylcarbonate polymer, similar to the conventional product. This is in view of the molding process. Namely, diethyleneglycol bisallylcarbonate polymer can be precisely molded by a glass molding die due to thermal polymerization of the plastic. In general, the surface of the front lens has a curvature which is designed to give the composite lens multi-focus or progressive multi-focus characteristics and is sometimes defined by an aspheric surface. Consequently, ; it is necessary to precisely mold the front lens.
Polycarbonate resin or polyurethane resin can be molded in a predetermined shape by an injection molding process. Injection molding of such resins does not yield a lens having a shape as precise as the lens made by the ~ . .' ~ -.
molding of diethyleneglycol bisallylcarbonate polymer in the glass molding die. However, the shape of the rear lens is simpler than that of the front lens. Accordingly, in the preparation of the rear lens, the simpler injection molding process will suffice.
Moreover, the percentage of shrinkage of polycarbonate resin or polyurethane resin is usually about 8%. This is considerably less than that of diethyleneglycol bisallylcarbonate polymer which has a percentage of shrinkage of about 12%. Consequently, the percentage of defective molded lenses that are produced is decreased, resulting in an increased yield of rear lenses, and accordingly, an increased yield of the composite plastic eyeglass lenses as a whole.
As can be seen from the above discussion, according to the present invention, the front lens, which usually has a complex shape that must be precisely molded in accordance with the desired multi-focus, progressive multi-focus, or aspheric surface characteristics, is made of diethyleneglycol bisallylcarbonate polymer. Conjointly, the rear lens, which is usually simpler in shape than the front lens, is made of polyurethane resin or polycarbonate resin having the necessary degree of mechanical strength.
The separate functions of the front lens and rear lens also contribute to an increase in the freedom of design thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be described below in detail with ;:
:
reference to the accompanying drawings, in which:
Fig. 1 is a sectional view of a composite eyeglass lens according to the present invention;
Fig. 2 is a schematic sectional view of a molding die which is used to mold a front plastic lens of a composite eyeglass lens located on an object side thereof, according to the present invention; and, Fig. 3 is a schematic sectional view of a molding die which is used to mold a rear plastic lens of a composite eyeglass lens located on a user's eye side thereof, according to the present invention.
.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In Fig. 1, a composite eyeglass lens 11 according to the present invention is comprised of a pair of plastic lenses, i.e., a front lens 12 on an object side and a rear lens 13 on a user's eye side thereof. In the illustrated embodiment, the composite eyeglass lens 11 has a negative power as a whole. The front lens 12 is made of diethyleneglycol bisallylcarbonate polymer (CR-39, n=1.5, ; ~ =55) and has a positive power. The rear lens 13 is made of polycarbonate resin (n=1.58, ~ =29) and has a negative power.
To mold the front lens 12, a molding cavity 24 de~ined by upper and lower lens molding dies 21 and 22, and gaskets 23 is filled with diethyleneglycol , ~ . . , , - ~' ~' :~
.
bisallylcarbonate polymer, as shown in Fig. 2. The front lens 12 can be molded by thermal polymerization of diethyleneglycol bisallylcarbonate polymer per se known.
On the other hand, the rear lens 13 is molded by injection molding polycarbonate resin in an injection molding cavity 27 defined by upper and lower molding dies 25 and 26, as shown in Fig. 3.
The mating surfaces 12a and 13a (defined by the molding surfaces of the lower molding die 22 and the upper molding die 25) of the front lens 12 and the rear lens 13 are identical in shape. The molded front lens 12 and the injection-molded rear lens 13 are adhered to each other at the mating surfaces 12a and 13a by, for example, a W
setting adhesive 14 ~Fig. 1) to form a composite plastic eyeglass lens 11 comprised of the front and rear lenses.
Since the rear lens 13 is made of polycarbonate resin having a large refractive index n, the thickness, particularly the thickness at the edge thereof, can be reduced in comparison with the conventional rear lens which is made of diethyleneglycol bisallylcarbonate polymer. The conventional rear lens made of diethyleneglycol bisallylcarbonate polymer is designated at a phantom line in Fig. 1. Consequently, the overall thickness and the edge thickness of the composite eyeglass lens 11, according to the present invention, is less than that of the -:
j: :
2~9328~
conventional composite eyeglass lens, resulting in a good appearance thereof.
Furthermore, the rear lens 13 provides sufficient mechanical strength for the eyeglass lens. In spite of the thin center portion thereof, the lens will not be destroyed or crushed by a steel ball in the drop-ball test.
Two examples of products (i.e., composite plastic eyeglass lenses) are shown below.
Example 1 Four rear lenses made of CR-39, polycarbonate resin, polyurethane resin 1, and polyurethane resin 2 were prepared. Numerical data of the four rear lenses is shown in Table 1 below , .
, : :
:
, .
.
2~93281 Table lens (dioptric) power(D) 5-3.40 5-3.40 5-3.40 5-3.40 refractive index 1.50 1.58 1.60 1.66 ..
first surface R (mm) 93.62 93.62 93.62 93.62 - ............................ _.
second surface R (mm~ 57.10460.32461.041 63.014 _ center thickness (mm) 0.8 0.8 0.8 0.8 edge thickness (mm) 7 0 6.0 S 54 5 33 ;
wherein, S represents a spherical lens surface;
PC represents polycarbonate;
PU 1 represents polyurethane 1; and, PU 2 represents polyurethane 2 In Table 1, the first surface R designates the radius (mm) of the mating lens surface 13a of the rear lens 13 -.
which is connected to the mating surface 12a of the front lens 12. The second surface R designates the radius (mm) of the lens surface of the rear lens 13 opposite the mating surface 13a.
As can be seen from Table 1, since the rear lens made of polycarbonate resin or polyurethane resin has a refractive index larger than that of the rear lens made of CR-39, it is possible to increase the radius R of the second surface to reduce the edge thickness thereof.
Example 2 Four rear lenses made of CR-39, polycarbonate resin, polyurethane resin 1, and polyurethane resin 2 were prepared, similar to Example 1 above. In Example 2, however, the four lenses are identical in shape. Namely, the radii R of the first and second surfaces are 93.62 mm and 57.104 mm, respectively, the center thickness 0.8 mm, and the edge thickness 7.0 mm. The lens degrees of the four lenses are shown in Table 2 below.
Table 2 ~IPU 1 _ lens power (D) 5-3.40 5-3.94 S-4.078 S-4.484 , -, ~
.
, . .
- :~
, .
20~3281 wherein, S represents a spherical power PC represents polycarbonate;
s PU 1 represents polyurethane 1; and, PU 2 represents polyurethane 2 As can be seen from Table 2, as long as the lenses have the same shape, the lens made of polycarbonate or polyurethane has a lens degree higher than that of the lens made of CR-39.
'
Claims (9)
1. A composite plastic eyeglass lens comprised of a front lens located on an object side of the eyeglass lens, and a rear lens located on a user's eye side of the eyeglass lens, wherein the rear lens is made of polycarbonate resin or polyurethane resin.
2. A composite plastic eyeglass lens according to claim 1, wherein the front lens is made of diethyleneglycol bisallylcarbonate polymer.
3. A composite plastic eyeglass lens according to claim 2, wherein the front lens is molded.
4. A composite plastic eyeglass lens according to claim 2, wherein the rear lens is injection molded.
5. A composite plastic eyeglass lens according to claim 1, wherein a surface of the front lens is a multi-focus surface, a progressive multi-focus surface or an aspheric surface.
6. A composite plastic eyeglass lens according to claim 1, wherein the rear lens has a negative power.
7. A composite plastic eyeglass lens according to claim 6, wherein the front lens is made of diethyleneglycol bisallylcarbonate polymer.
8. A composite plastic eyeglass lens according to claim 7, wherein the front lens is molded, and the rear lens is injection molded.
9. A composite plastic eyeglass lens according to claim 8, wherein a surface of a front lens is a multi-focus surface, a progressive multi-focus surface, or an aspheric surface.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4-81822 | 1992-04-03 | ||
| JP8182292A JPH05281497A (en) | 1992-04-03 | 1992-04-03 | Combined spectacle lens |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2093281A1 true CA2093281A1 (en) | 1993-10-04 |
Family
ID=13757182
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002093281A Abandoned CA2093281A1 (en) | 1992-04-03 | 1993-04-02 | Lens for eyeglasses |
Country Status (3)
| Country | Link |
|---|---|
| JP (1) | JPH05281497A (en) |
| CA (1) | CA2093281A1 (en) |
| FR (1) | FR2689654A1 (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AU671643B2 (en) * | 1992-04-15 | 1996-09-05 | 2C Optics, Inc. | Lenses with high impact resistance and high scratch resistance |
| EP0734543B1 (en) * | 1993-12-07 | 2005-06-08 | Vsi International, Llc | Aliphatic thermoplastic poyurethane press-on lenses and eyeglasses embodying the same |
| US6170952B1 (en) | 1993-12-07 | 2001-01-09 | Neoptx, Inc. | Adherent corrective lenses and eyeglasses embodying the same |
| FR2740231B1 (en) * | 1995-10-20 | 1998-03-06 | Christian Dalloz Sa | DRAFT FOR NON-CORRECTOR EYEPIECE |
| FR2793038B1 (en) | 1999-04-29 | 2002-01-25 | Essilor Int | COMPOSITE OPHTHALMIC LENS AND METHOD FOR OBTAINING SUCH A LENS |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5662202A (en) * | 1979-10-25 | 1981-05-28 | Matsushita Electric Ind Co Ltd | Composite lens |
| US4690512A (en) * | 1985-01-28 | 1987-09-01 | Polaroid Corporation | Composite lens assembly |
| EP0240492A1 (en) * | 1985-10-11 | 1987-10-14 | C & H CONTACT LENS, INC. | Composite ophthalmic lens system |
| US4969729A (en) * | 1988-08-19 | 1990-11-13 | 501 Opticast International Corporation | Composite plastic lens having a positioned optical axis and method of making the same |
| JPH03230920A (en) * | 1990-02-05 | 1991-10-14 | Toshiba Corp | Plastic lens, manufacture of plastic lens and die for molding plastic lens |
| JP2613486B2 (en) * | 1990-03-30 | 1997-05-28 | 旭光学工業株式会社 | Laminated spectacle lens and method of manufacturing the same |
-
1992
- 1992-04-03 JP JP8182292A patent/JPH05281497A/en active Pending
-
1993
- 1993-04-02 CA CA002093281A patent/CA2093281A1/en not_active Abandoned
- 1993-04-05 FR FR9303971A patent/FR2689654A1/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| JPH05281497A (en) | 1993-10-29 |
| FR2689654A1 (en) | 1993-10-08 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Discontinued | ||
| FZDE | Discontinued |
Effective date: 19951002 |