US4614624A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of molding bifocal lenses
Assignee: Sunsoft Corp
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Filing: 1985-05-14
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Granted: 1986-09-30
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Expires: 2005-05-14
Abstract
Abstract A method of simultaneously casting the convex and concave surfaces on a one piece crescent shaped segment bifocal lens. A metal mold is made by lathe cutting and polishing a first convex short radius optical surface in the central area of a metal disk shaped blank. The second longer convex radius optical surface having from 0.25 to 3.0 prism diopters and intersecting the first curve at the center of the blank is cut and polished on the metal blank. A resinous bifocal concave mold is made by replication from the metal convex mold. A second convex resinous optical mold is aligned on the concave bifocal resinous mold and the space between filled with the liquid lens monomer. The monomer is polymerized to form a solid polymer bifocal lens.
Inventors
- 👤 Charles W. Neefe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 00:39
CPC Classifications
B; B29; B29D; B29D11/00; B29D11/00009; B29D11/00028; Y; Y10; Y10S; Y10S425/00; Y10S425/808
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
257 words
A method of simultaneously casting from a liquid lens monomer the concave and convex surfaces of a one piece bifocal lens having a crescent shaped shorter radius segment by the steps of, providing a metal mold blank, cutting and polishing a first shorter radius optical surface in the central area of the metal mold blank, the first central circular shaped optical surface has a diameter equal to the width of the crescent shaped shorter radius lens segment, cutting and polishing a second longer radius optical surface on the metal mold having its center of curvature displaced from the shorter radius center of curvature to provide from 0.25 prism diopters to 3.0 prism diopters of refraction in the bifocal lens, the longer radius convex optical mold surface intersects the shorter radius convex mold optical surface to provide a crescent shaped shorter radius convex bifocal optical mold surface, a concave resinous negative image of the bifocal metal mold is made by applying a heated and softened resin mold material against the metal convex bifocal mold, a convex resinous optical mold is aligned with the bifocal concave resinous optical mold and the space between the concave bifocal resinous mold and the convex resinous mold is filled with a selected liquid lens monomer capable of being polymerized, the selected liquid lens monomer is allowed to polymerize between the convex resinous mold surface and the concave bifocal resinous mold surface forming a solid bifocal lens having a crescent shape shorter radius segment, the solid bifocal lens is removed from the resinous molds.
Claim 2
Independent Claim
257 words
A method of simultaneously casting from a liquid lens monomer the concave and convex surfaces of a one piece bifocal lens having a crescent shaped shorter radius segment by the steps of, providing a metal mold blank, cutting and polishing a first shorter radius optical surface in the central area of the metal mold blank, the first central circular shaped optical surface has a diameter equal to the width of the crescent shaped shorter radius lens segment, cutting and polishing a second longer radius optical surface on the metal mold having its center of curvature displaced from the shorter radius center of curvature to provide from 0.25 prism diopters to 3.0 prism diopters of refraction in the bifocal lens, the longer radius convex optical mold surface intersects the shorter radius convex mold optical surface to provide a crescent shaped shorter radius convex bifocal optical mold surface, a concave resinous negative image of the bifocal metal mold is made by applying a heated and softened resin mold material against the metal convex bifocal mold, a convex resinous optical mold is aligned with the bifocal concave resinous optical mold and the space between the concave bifocal resinous mold and the convex resinous mold is filled with a selected liquid lens monomer capable of being polymerized, the selected liquid lens monomer is allowed to polymerize between the convex resinous mold surface and the concave bifocal resinous mold surface forming a solid bifocal lens having a crescent shape shorter radius segment, the solid bifocal lens is removed from the resinous molds.
Claim 3
Dependent Claim
18 words
A method as in claim 1 wherein the prism is present only in the longer radius lens segment.
Claim 4
Dependent Claim
19 words
A method as in claim 1 wherein the prism is present only in the shorter radius crescent shaped segment.
Claim 5
Dependent Claim
16 words
A method as in claim 1 wherein the prism is divided between the two bifocal segments.
Claim 6
Dependent Claim
12 words
A method as in claim 1 wherein the lens is truncated inferiorly.
Claim 7
Dependent Claim
13 words
A method as in claim 1 wherein the upper lens edge is thinned.
Claim 8
Dependent Claim
13 words
A method as in claim 1 wherein the lower lens edge is thinned.
Claim 9
Dependent Claim
22 words
A method as in claim 1 wherein vertical grooves are cut near the upper edge on the convex surface of the lens.
Claim 10
Dependent Claim
25 words
A method as in claim 1 wherein eccentric rotation is used to displace the center of curvature from the geometric center to provide the prism.
References Cited (Backward Citations)
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Cited
US3460928A
Cited
US3806079A
Cited
US4163655A
Cited
US4239712A
Cited
US4279401A
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-09-29 | 1990-03-31 | 1990-09-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-09-29 | 1994-03-31 | 1994-09-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-09-29 | 1998-03-31 | 1998-09-30 | $7700.00 | Window Closed / Lapsed |