US3653933A
Expired / Lapsed
US
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Anomalous dispersion optical glass having a good weather proof characteristic
Assignee: Nikon Corp
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Filing: 1969-08-22
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Granted: 1972-04-04
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Expires: 1989-08-22
Abstract
Abstract This invention provides an anomalous dispersion optical glass having a good weatherproof characteristic, in which the composition (mixing composition) range of the glass in weight percent is essentially as follows: B2O3 10-40 SiO2 3-45 SiO2+ 25 B2O3 30 1/2 SiO2 A12O3 8-12 PbO 25-60 and a portion of PbO is replaced with 0-8 weight percent of La2O3 and/or RO when desired, and, a portion of PbO is replaced with at least 3 weight percent of La2O3 and/or CaO when B2O3> SiO2 + 20 is satisfied or when SiO2 + 20 > OR = B2O3 and B2O3 > OR = 35 are both satisfied, and Nd and Vd lie within the ranges Nd 1.52-1.74 and Vd 33-52.
Inventors
- 👤 Munehisa Tsunekawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:53
CPC Classifications
C; C03; C03C; C03C3/00; C03C3/04; C03C3/062; C03C3/07; C03C3/072; Y; Y10; Y10S; Y10S501/00; Y10S501/90; Y10S501/903
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
101 words
An anomalous dispersion optical glass having a good weatherproof characteristic consisting essentially in weight per cent of: SiO2 3-45 Al2O3 8-12 La2O3 0-8 RO 0-8 B2O3 10-40 PbO 25-60 SiO2 + 25 > or = B2O3 > or = 30 1/2 SiO2 B2O3 > SiO2 + 20 wherein at least 3 to 8 percent of PbO is replaced with at least one oxide selected from the group consisting of RO, La2O3 and mixtures thereof and RO is bivalent metal oxide other than PbO and selected from MgO, CaO, SrO, BaO, ZnO, CdO and mixtures thereof and Nd 1.52-1.74 and Vd 33-52.
Claim 2
Dependent Claim
13 words
An anomalous dispersion optical glass according to claim 1, wherein RO is CaO.
Claim 3
Dependent Claim
13 words
An anomalous dispersion optical glass according to claim 2 wherein RO is CaO.
References Cited (Backward Citations)
US2393448A
Cited
US2468868A
Cited
GB783110A
Cited
US3069294A
Cited
US3149984A
Cited
US3493405A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-04-04 | 1975-10-04 | 1976-04-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-04-04 | 1979-10-04 | 1980-04-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-04-04 | 1983-10-04 | 1984-04-04 | $7700.00 | Window Closed / Lapsed |