Patent US4179300A successfully refreshed from Google Patents.
US4179300A
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US
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Optical glass
Assignee: Hoya Corp
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Filing: 1978-01-20
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Granted: 1979-12-18
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Expires: 1998-01-20
Abstract
Abstract An optical glass having a refractive index of 1.66 to 1.77 and an Abbe number of 30 to 50 and superior chemical stability, which comprises, in % by weight, 30 to 45% SiO 2 ; 0 to 6% B 2 O 3 ; 1 to 5% Li 2 O; 0 to 4% Na 2 O+K 2 O; 20 to 40% BaO; 5 to 20% MgO+CaO+SrO+ZnO, with the proviso of 0 to 15% MgO, 0 to 20% CaO, 0 to 20% SrO, and 0 to 15% ZnO; 2 to 7% ZrO 2 ; 2 to 20% TiO 2 ; and 0 to 10% La 2 O 3 +Ta 2 O 5 +Nb 2 O 5 +WO 3 , with the proviso of 0 to 10% La 2 O 3 , and 0 to 4% Ta 2 O 5 +Nb 2 O 5 +WO 3 .
Inventors
- 👤 Hiroji Sagara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 09:21
CPC Classifications
C; C03; C03C; C03C3/00; C03C3/04; C03C3/076; C03C3/089; C03C3/062; C03C3/078; Y; Y10; Y10S; Y10S501/00; Y10S501/90; Y10S501/903
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
71 words
An optical glass not containing PbO and consisting essentially of, in percent by weight, about 33.0% SiO 2 , about 4.0% B 2 O 3 , about 2.0% Li 2 O, about 27.4% BaO, about 5.9% CaO, about 4.3% ZnO, about 5.0% ZrO 2 , and about 18.4% TiO 2 having a refractive index of about 1.7630, and Abbe number of about 33.0 and an acid resistance of less than 0.1%.
Claim 2
Dependent Claim
71 words
An optical glass not containing PbO and consisting essentially of, in percent by weight, about 33.0% SiO 2 , about 4.0% B 2 O 3 , about 2.0% Li 2 O, about 27.4% BaO, about 5.9% CaO, about 4.3% ZnO, about 5.0% ZrO 2 , and about 18.4% TiO 2 having a refractive index of about 1.7630, and Abbe number of about 33.0 and an acid resistance of less than 0.1%.
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) | 1982-12-17 | 1983-06-18 | 1983-12-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-12-17 | 1987-06-18 | 1987-12-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-12-17 | 1991-06-18 | 1991-12-18 | $7700.00 | Window Closed / Lapsed |