Patent US4057435A successfully refreshed from Google Patents.
US4057435A
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Optical glasses
Assignee: Corning Glass Works
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Filing: 1976-10-08
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Granted: 1977-11-08
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Expires: 1996-10-08
Abstract
Abstract Glasses are disclosed that have a high refractive index on the order of 1.7 or greater, a low density on the order of 3 gm./cm. 3 , good chemical durability and a dispersive index on the order of 40 or more. These glasses belong to a CaO--La 2 O 3 --TiO 2 --B 2 O 3 --SiO 2 family and are particularly useful in strong correction ophthalmic lenses and space optics.
Inventors
- 👤 Jean E. Boudot
- 👤 Pascal A. J. Joly
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 04:36
CPC Classifications
C; C03; C03C; C03C3/00; C03C3/04; C03C3/062; C03C3/064; C03C3/068; Y; Y10; Y10S; Y10S501/00; Y10S501/90; Y10S501/903
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
125 words
A glass having a composition within the CaO--La 2 O 3 --TiO 2 --B 2 O 3 --SiO 2 family and having a refractive index at least on the order of 1.7, a dispersive index at least on the order of 40, a density of about 3 g/cm 3 , and a weight loss, as measured in the AO test, of less than 5 mg/cm 2 , consisting essentially, as calculated in weight percent on the oxide basis, of about 18-28% CaO, 9-15% La 2 O 3 , 9-15% TiO 2 , 30-54% B 2 O 3 , and the remainder SiO 2 , the SiO 2 content not exceeding 15% and the sum of B 2 O 3 + SiO 2 being about 30-54%.
Claim 2
Dependent Claim
125 words
A glass having a composition within the CaO--La 2 O 3 --TiO 2 --B 2 O 3 --SiO 2 family and having a refractive index at least on the order of 1.7, a dispersive index at least on the order of 40, a density of about 3 g/cm 3 , and a weight loss, as measured in the AO test, of less than 5 mg/cm 2 , consisting essentially, as calculated in weight percent on the oxide basis, of about 18-28% CaO, 9-15% La 2 O 3 , 9-15% TiO 2 , 30-54% B 2 O 3 , and the remainder SiO 2 , the SiO 2 content not exceeding 15% and the sum of B 2 O 3 + SiO 2 being about 30-54%.
Claim 3
Dependent Claim
90 words
A glass according to claim 1 also optionally containing at least one of the following components in the indicated proportions of 0-5% MgO, 0-15% BaO, the sum of BaO + CaO being about 20-34%, 0-4% Na 2 O, 0-4% Li 2 O, the sum of Na 2 O + Li 2 O being about 0-4%, 0-5% Al 2 O 3 , 0-5% Gd 2 O 3 , 0-5% Y 2 O 3 , 0-5% Nb 2 O 5 , 0-4% ZrO 2 , 0-4% WO 3 , and 0-4% ZnO.
Claim 4
Dependent Claim
43 words
A glass according to claim 1 wherein the SiO 2 content is about 9-11%, the B 2 O 3 content is about 36-43%, the TiO 2 is about 9-13%, the CaO is about 18-28% and the La 2 O 3 is about 9-11%.
References Cited (Backward Citations)
US3960579A
Cited
US3935020A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-11-07 | 1981-05-09 | 1981-11-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-11-07 | 1985-05-09 | 1985-11-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-11-07 | 1989-05-09 | 1989-11-08 | $7700.00 | Window Closed / Lapsed |