Process for applying a film structure onto a lens blank

Patent metadata

Field	Value
Publication number	US-9778485-B2
Application number	US-201013880023-A
Country	US
Kind code	B2
Filing date	Oct 21, 2010
Priority date	Oct 21, 2010
Publication date	Oct 3, 2017
Grant date	Oct 3, 2017

Abstract

A process for applying a film structure onto a lens blank is improved by implementing a wedge piece when the film structure is pressed against the lens blank using a resilient cushion. The wedge piece forces the film structure to conform more tightly to the lens blank within a depression track existing on said lens blank. Then, the lens blank assembled with the film structure has a final optically useful area which is increased.

First claim

The invention claimed is:

1. A process to apply a film structure onto a lens blank, said lens blank being limited by a top face, a bottom face and a peripheral edge connecting said top face to said bottom face, said top face comprising a convex surface portion and a margin portion located between the convex surface portion and the peripheral edge, the convex surface portion and the margin portion forming a re-entrant angle along a depression track between said convex surface portion and said margin portion, the process comprising:
arranging the film structure between the top face of the lens blank and a resilient cushion;
pressing the film structure against the top face of the lens blank by moving the resilient cushion and the lens blank closer to each other, thereby deforming the resilient cushion and suppressing a gap existing initially between the film structure and the top face of the lens blank, with a contact area of said film structure with said top face which increases when the resilient cushion is being deformed, said contact area increasing progressively from an initial area comprised within the convex surface portion to a final area astride at least a part of said convex surface portion and at least a part of the margin portion adjacent said part of the convex surface portion, and
arranging a closed-loop shaped wedge piece between the resilient cushion and the film structure, said wedge piece being pressed against the film structure by the resilient cushion being deformed, and said wedge piece being deformed to be situated in line with the depression track when the contact area has reached the final area, along a moving direction of the resilient cushion and the lens blank with respect to each other,
wherein the wedge piece is arranged initially so that a projection of said wedge piece onto the top face of the lens blank, along the moving direction, is contained within the convex surface portion apart from the depression track, and the resilient cushion causes the wedge piece to slide towards said depression track as the resilient cushion is deformed.

2. The process according to claim 1 , wherein the wedge piece is located initially so that the projection of the wedge piece along the moving direction onto the top face of the lens blank is between 1 mm and 10 mm from the depression track, inwards of the convex surface portion.

3. The process according to claim 2 , wherein the wedge piece is located initially so that the projection of the wedge piece along the moving direction onto the top face of the lens blank is between 1.5 mm and 3 mm from the depression track.

4. The process according to claim 1 , wherein the margin portion surrounds the convex surface portion within the top face of the lens blank.

5. The process according to claim 4 , wherein the depression track is a circle around the convex surface portion, and the wedge piece is initially ring-shaped.

6. The process according to claim 5 , wherein the wedge piece is an O-ring.

7. The process according to claim 1 , wherein the wedge piece is resilient.

8. The process according to claim 7 , wherein the wedge piece is rubber-based.

9. The process according to claim 1 , wherein a thickness of the wedge piece is between 1 mm and 2.5 mm, measured along the moving direction.

10. The process according to claim 1 , wherein the margin portion is planar.

11. The process according to claim 1 , wherein further comprising:
arranging an adhesive material layer initially between the film structure and the top face of the lens blank, and fixing said film structure onto said lens blank using the adhesive material layer.

12. The process according to claim 1 , wherein the lens blank is an ophthalmic lens blank designed for eyeglass production, with the convex surface portion forming an optically useful area of said eyeglass.

13. The process according to claim 1 , wherein the film structure comprises an anti-reflection coating.

14. The process according to any claim 1 , wherein the film structure is suitable for producing a light-polarizing effect.

15. The process according to claim 1 , wherein the resilient cushion is an inflatable bladder supported fixedly with respect to the lens blank, and wherein a suppression of the gap between the top face of said lens blank and the resilient cushion is produced by inflating said bladder.

Assignees

• Chiu Hao-Wen
• Gou Zeming
• Essilor Int

Inventors

• Chiu Hao-Wen
• Gou Zeming

Classifications

• Y10T156/1028

  by bending, drawing or stretch forming sheet to assume shape of configured lamina while in contact therewith · CPC title

• B29D11/0073

  Optical laminates · CPC title

• B29L2011/0016

  Lenses · CPC title

• G02C7/024 Primary

  Methods of designing ophthalmic lenses · CPC title

• B29C63/16 Primary

  applied by "rubber" bag or diaphragm · CPC title