US3888692A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Flint optical glass
Assignee: Fujifilm Holdings Corp
•
Filing: 1973-08-21
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Granted: 1975-06-10
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Expires: 1993-08-21
Abstract
Abstract A weather-proof, flint, optical glass composition comprising, on a percent by weight basis, from 12.5 to 19.5% SiO2, from 8.0 to 16.5% Al2O3, from 12.0 to less than 20.0% B2O3, and from 42.0 to 60.0% PbO.
Inventors
- 👤 Shigeo Kuwayama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 08:45
CPC Classifications
C; C03; C03C; C03C4/00; C03C4/20; C03C3/00; C03C3/04; C03C3/062; C03C3/07; C03C3/072; C03C3/074; C03C3/0745; Y; Y10; Y10S; Y10S501/00; Y10S501/90; Y10S501/903
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
42 words
A WEATHER-PROOF FLINT OPTICAL ANASTIGMATIC GLASS CONSISTING ESSENTIALLY OF ON A PERCENT BY WEIGHT BASIS FROM 12.5 TO 19.5 PERCENT SIO2, FROM 8.0 TO 16.5 PERCENT AL2O3, FROM 12.0 TO LESS THAN 20.0 PERCENT B2O3 AND FROM 42.0 TO 60.0 PERCENT PBO.
Claim 2
Dependent Claim
42 words
A WEATHER-PROOF FLINT OPTICAL ANASTIGMATIC GLASS CONSISTING ESSENTIALLY OF ON A PERCENT BY WEIGHT BASIS FROM 12.5 TO 19.5 PERCENT SIO2, FROM 8.0 TO 16.5 PERCENT AL2O3, FROM 12.0 TO LESS THAN 20.0 PERCENT B2O3 AND FROM 42.0 TO 60.0 PERCENT PBO.
Claim 3
Dependent Claim
38 words
The glass of claim 1, wherein the glass contains up to 10 percent by weight based on the total weight of glass of an oxide selected from the group consisting of Ta2O5, La2O3, ThO2, Nb2O5 and mixtures thereof.
Claim 4
Dependent Claim
24 words
The glass of claim 1, wherein the glass contains up to 11 percent by weight based on the total weight of glass of Sb2O3.
Claim 5
Dependent Claim
24 words
The glass of claim 1, wherein the glass contains less than 1 percent by weight based on the total weight of glass of P2O5.
Claim 6
Dependent Claim
25 words
The glass of claim 1, wherein the glass contains up to about 10 percent by weight based on the total weight of glass of ZnO.
Claim 7
Dependent Claim
37 words
The glass of claim 1, wherein the glass contains up to about 4 percent by weight based on the total weight of glass of an oxide selected from the group consisting of WO3, TiO2 and mixtures thereof.
Claim 8
Dependent Claim
28 words
The glass of claim 1, wherein the glass contains up to about 5 percent by weight based on the total weight of glass of alkaline earth metal oxides.
Claim 9
Dependent Claim
25 words
The glass of claim 1, wherein the glass contains up to about 5 percent by weight based on the total weight of glass of As2O3.
Claim 10
Dependent Claim
27 words
The glass of claim 1, wherein the glass contains up to about 5 percent by weight based on the total weight of glass of alkali metal oxides.
Claim 11
Dependent Claim
22 words
The glass of claim 1, wherein the refractive index nD of said flint optical glass ranges from about 1.68 to about 1.80.
References Cited (Backward Citations)
US3149984A
Cited
US3653933A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-06-09 | 1978-12-09 | 1979-06-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-09 | 1982-12-09 | 1983-06-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-09 | 1986-12-09 | 1987-06-10 | $7700.00 | Window Closed / Lapsed |