US3915723A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Photochromic multifocal lenses and method of fabrication thereof
Assignee: American Optical Corp
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Filing: 1973-11-09
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Granted: 1975-10-28
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Expires: 1993-11-09
Abstract
Abstract A high index of refraction, low softening point, low expansion segment glass is fused into a countersunk photochromic glass blank of lower index of refraction. The high index of refraction segment is primarily composed of SiO2, B2O3, and PbO with lesser amounts of other oxides.
Inventors
- 👤 Lee O Upton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 11:13
CPC Classifications
C; C03; C03C; C03C3/00; C03C3/04; C03C3/062; C03C3/07; C03C3/072; C03C3/074; C03C4/00; C03C4/04; C03C4/06; G; G02; G02C; G02C7/00; G02C7/02; G02C7/06; G02C7/10; G02C7/102; G02C2202/00; G02C2202/16; Y; Y10; Y10S; Y10S501/00; Y10S501/90; Y10S501/903
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
29 words
A GLASS OF HIGH REFRACTIVE INDEX ADAPTABLE TO FUSIN WITH A PHOTOCHROMIC GLASS OF LOWER REFRATIVE INDEX CONSISTING ESSENTIALLY OF THE FOLLOWING INGREDIENTS IN THE RAGE OF WEIGHT PERCENT:
Claim 2
Dependent Claim
29 words
A GLASS OF HIGH REFRACTIVE INDEX ADAPTABLE TO FUSIN WITH A PHOTOCHROMIC GLASS OF LOWER REFRATIVE INDEX CONSISTING ESSENTIALLY OF THE FOLLOWING INGREDIENTS IN THE RAGE OF WEIGHT PERCENT:
Claim 3
Dependent Claim
18 words
A glass according to claim 1 consisting essentially of the following ingredients in the range of weight percent:
Claim 4
Dependent Claim
18 words
A glass according to claim 1 consisting essentially of the following ingredients in the range of weight percent:
Claim 5
Dependent Claim
15 words
A glass according to claim 1 consisting essentially of the following ingredients by weight percent:
Claim 6
Dependent Claim
15 words
A glass according to claim 1 consisting essentially of the following ingredients by weight percent:
Claim 7
Dependent Claim
15 words
A glass according to claim 1 consisting essentially of the following ingredients by weight percent:
Claim 8
Dependent Claim
15 words
A glass according to claim 1 consisting essentially of the following ingredients by weight percent:
Claim 9
Dependent Claim
15 words
A glass according to claim 1 consisting essentially of the following ingredients by weight percent:
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-10-27 | 1979-04-28 | 1979-10-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-10-27 | 1983-04-28 | 1983-10-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-10-27 | 1987-04-28 | 1987-10-28 | $7700.00 | Window Closed / Lapsed |