Method of making ophthalmic lenses with a structured surface

Patent metadata

Field	Value
Publication number	US-9492978-B2
Application number	US-201113977974-A
Country	US
Kind code	B2
Filing date	Jan 4, 2011
Priority date	Jan 4, 2011
Publication date	Nov 15, 2016
Grant date	Nov 15, 2016

Abstract

A method for fabricating a Fresnel lens or other lens having a structured surface such as refractive and/or diffractive bi-focal or other multi-focal lenses includes press-coating the structured surface with a low or very low refractive index coating material. The coating is sufficient thick to adequately cover the structured surface so that a smooth coating surface with good optical properties is obtained, for example in the case of a Fresnel structure a thickness greater than 1.5 times and less than 5 times the Fresnel structure height, and is cured in situ. A film, e.g., of PET, PC or PU or a film stack, e.g. a TAC/PVA/TAC film stack is prepared and a heat melting adhesive is applied to the side of the film or film stack to be contacted with the coated structured surface of the lens blank. The film or film stack is then laminated to the cured coating.

First claim

The invention claimed is:

1. A method for fabricating an ophthalmic lens, comprising:
providing a lens blank made of a transparent optical quality material, the lens blank having a structured surface and a non-structured surface, the structured surface having a base curvature, the structured surface being defined by a plurality of peaks and valleys;
applying a resin coating to the structured surface of the lens blank so that the resin coating covers the structured surface and has a smooth free surface with a curvature corresponding to the base curvature of the structured surface;
curing the resin coating in situ on the lens blank in a mold part with a UV lamp, wherein a material of the resin coating has a refractive index is between about 1.38 and about 1.55;
providing a rigid film or film stack; and
laminating or bonding the film or film stack to the resin coating, wherein,
a) the UV lamp is disposed on the side of the lens blank remote from the mold part, and not on a mold side, and is configured to emit incident UV radiation which is directed at the non-structured surface of the lens blank, and
b) successively, the rays of the incident UV radiation first pass through the non-structured surface of the Fresnel lens blank, which is opposite the structured surface of the Fresnel lens blank, then the rays of reach the valleys of the structured surface of the Fresnel lens blank before reaching the resin coating, then the rays reach and cure the resin coating, and then the rays pass through the transparent mold part at the opposite of the non-structured surface.

2. The method for fabricating an ophthalmic lens according to claim 1 , wherein the laminating or bonding step includes application of an adhesive to the film or film stack and application of pressure to the film or film stack brought into contact with the cured resin coating.

3. The method for fabricating an ophthalmic lens according to claim 2 , wherein the adhesive is a hot melt adhesive (HMA) dried before it is brought into contact with the resin coating.

4. The method for fabricating an ophthalmic lens according to claim 3 , wherein the hot melt adhesive comprises polyurethane based heat-activatable adhesive materials.

5. The method for fabricating an ophthalmic lens according to claim 4 , wherein the hot melt adhesive is selected from the group consisting of polyolefins, polyamides, polyurethanes, polyurethane/ureas, polyvinypyrrolidones, polyesters, polyesteramides, poly(oxazolines) and poly(meth)acrylic systems and combinations thereof.

6. The method for fabricating an ophthalmic lens according to claim 2 , wherein the adhesive is a pressure sensitive adhesive (PSA).

7. The method for fabricating an ophthalmic lens according to claim 2 , wherein the adhesive comprises a bi-layer system comprising a layer of a hot melt adhesive and a layer of latex.

8. The method for fabricating an ophthalmic lens according to claim 1 , wherein the film stack is a polarizing film stack for producing a polarized ophthalmic lens blank.

9. The method for fabricating an ophthalmic lens according to claim 1 , wherein the lens blank is a Fresnel lens blank having a Fresnel structure height on the structured surface.

10. The method for fabricating an ophthalmic lens according to claim 9 , wherein the Fresnel structure height is between about 20 μm and about 500 μm.

11. The method for fabricating an ophthalmic lens according to claim 9 , wherein a thickness of the coating is greater than 1.5 times the Fresnel structure height and less than 5 times the Fresnel structure height.

12. The method for fabricating an ophthalmic lens according to claim 9 , wherein the Fresnel structure height is between about 20 μm and about 300 μm.

13. The method for fabricating an ophthalmic lens according to claim 12 , wherein the thickness of the resin coating is between about 1.5 times the Fresnel structure height and about 3 times the Fresnel structure height.

14. The method for fabricating an ophthalmic lens according to claim 9 , wherein a refractive index of a bulk material of the Fresnel lens blank is between about 1.59 and about 1.74.

15. The method for fabricating an ophthalmic lens according to claim 1 , wherein the thickness of the resin coating is between about 75 and 750 μm.

16. The method for fabricating an ophthalmic lens according to claim 1 , wherein a difference in the refractive indexes of a bulk material of the lens blank and the material of the cured resin coating is greater than about 0.05.

17. The method for fabricating an ophthalmic lens according to claim 1 , wherein a difference in the refractive indexes of a bulk material of the lens blank and the material of the cured resin coating is greater than about 0.15.

18. The method for fabricating an ophthalmic lens according to claim 1 , wherein materials of resin coating formulations for producing the resin coating comprise UV curable compounds selected from the group consisting of UV curable (meth)acrylic compounds, epoxy acrylic compounds, epoxy compounds, polyurethane acrylic compounds, fluoro-acrylic compounds and any mixture of the aforesaid compounds.

19. The method for fabricating an ophthalmic lens according to claim 1 , wherein a bulk material of the lens blank comprises a thermoplastic polycarbonate or a thermosetting polymer obtained by curing compounds selected from thiourethane group(s) and/or episulfur group(s).

20. The method for fabricating an ophthalmic lens according to claim 1 , wherein the rigid film or film stack comprises a film stack or multilayer film encapsulating PVA (polyvinyl alcohol) layer between rigid films, the PVA layer being a polarizing layer.

21. The method for fabricating an ophthalmic lens according to claim 20 , wherein the film stack comprises a TAC/PVA/TAC film stack.

22. The method for fabricating an ophthalmic lens according to claim 1 , wherein the rigid film or film stack comprises a film stack selected from the group consisting of TAC/PVA/TAC film stacks, CAB/PVA/CAB film stacks, PC/PVA/PC film stacks and polarized PET films.

23. The method for fabricating an ophthalmic lens according to claim 1 , wherein the film or film stack comprises a rigid film selected from the group consisting of polyethylene terephthalate (PET) films, thermoplastic polycarbonate (PC) films and thermoplastic polyurethane (PU) films.

24. The method for fabricating an ophthalmic lens according to claim 1 , wherein the lens blank is one of the group consisting of a Fresnel lens blank, a refractive bi-focal lens blank, a diffractive bi-focal lens blank, and a multi-focal lens blank.

25. A method for fabricating an ophthalmic lens, comprising:
providing a lens blank made of a transparent optical quality material, the lens blank having a structured surface and a non-structured surface, the structured surface having a base curvature, the structured surface being defined by a plurality of peaks and valleys;
applying a resin coating to the structured surface of the lens blank so that the resin coating covers the structured surface and has a smooth free surface with a curvature corresponding to the base curvature of the structured surface;
curing the resin coating in situ on the lens blank in a mold part with a UV lamp to produce cured resin coating material with a refractive index lower than a refractive index of a bulk material of the lens blank;
providing a film; and
laminating the film to the resin coating, wherein,

Assignees

• Jiang Peiqi
• Keegan Bruce
• Essilor Int

Inventors

• Jiang Peiqi
• Keegan Bruce

Classifications

• Y10T156/10

  Methods of surface bonding and/or assembly therefor · CPC title

• B29D11/0073

  Optical laminates · CPC title

• B29D11/00865

  Applying coatings; tinting; colouring (printing, marking or copying processes B41M; identification in general G09F3/00; producing decorative effects in general B44C; positioning or marking of lenses B24B13/0055) · CPC title

• G02C7/022

  Ophthalmic lenses having special refractive features achieved by special materials or material structures (G02C7/049 takes precedence) · CPC title

• B29D11/00028 Primary

  Bifocal lenses; Multifocal lenses · CPC title