US3880631A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of identifying chemically tempered ophthalmic lenses
Assignee: Corning Glass Works
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Filing: 1973-11-23
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Granted: 1975-04-29
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Expires: 1993-11-23
Abstract
Abstract Ophthalmic lenses to be subjected to chemical tempering are provided with a prussian blue edge marking prior to the tempering process. After tempering, the characteristic yellow color of the edge marking provides a ready means of determining that the lens has been subjected to chemical tempering.
Inventors
- 👤 Donald M Ripley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 00:30
CPC Classifications
G; G02; G02C; G02C7/00; G02C7/02; G02C7/021; C; C03; C03C; C03C21/00
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
44 words
IN A METHOD FOR CHEMICALLY-TEMPERING AN OPHTHALMIC LENS WHICH COMPRISES EXPOSURE OF THE LENS TO A SOURCE OF EXCHANGEABLE ALKALI METAL IONS AT A TEMPERATURE IN EXCESS OF 350*C., THE IMPROVEMENT WHICH COMPRISES: APPLYING TO AT LEAST A PORTION OF THE LENS TO EXPOSURE
Claim 2
Dependent Claim
44 words
IN A METHOD FOR CHEMICALLY-TEMPERING AN OPHTHALMIC LENS WHICH COMPRISES EXPOSURE OF THE LENS TO A SOURCE OF EXCHANGEABLE ALKALI METAL IONS AT A TEMPERATURE IN EXCESS OF 350*C., THE IMPROVEMENT WHICH COMPRISES: APPLYING TO AT LEAST A PORTION OF THE LENS TO EXPOSURE
Claim 3
Dependent Claim
24 words
A method according to claim 1 wherein the coating is applied to at least a portion of the ground edge of the ophthalmic lens.
Claim 4
Dependent Claim
17 words
A method according to claim 2 wherein the prussian blue indicator is a hydrated potassium ferric ferrocyanide.
Claim 5
Dependent Claim
17 words
A method according to claim 3 wherein the coating consists essentially of potassium ferric ferrocyanide and water.
References Cited (Backward Citations)
US2354772A
Cited
US3094379A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-04-28 | 1978-10-28 | 1979-04-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-28 | 1982-10-28 | 1983-04-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-28 | 1986-10-28 | 1987-04-29 | $7700.00 | Window Closed / Lapsed |