US3601474A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Triplet objective
Assignee: Ernst Leitz Wetzlar GmbH
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Filing: 1970-07-13
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Granted: 1971-08-24
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Expires: 1990-07-13
Abstract
Abstract An objective specially designed for a field angle of approximately 30* and having a large relative opening of at least f:2.8 comprises three separate lens elements, each of which being assembled from two single lenses of opposite refractive power which are cemented together.
Inventors
- 👤 Georg Knetsch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 13:12
CPC Classifications
G; G02; G02B; G02B9/00; G02B9/12
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
45 words
A triplet objective having a relative opening of at least f: 2.8 and a field angle of approximately 30* comprising three lens members, each member being cemented together from two single lenses having opposite refractive power, said lens members having substantially the following approximate specifications:
Claim 2
Dependent Claim
45 words
A triplet objective having a relative opening of at least f: 2.8 and a field angle of approximately 30* comprising three lens members, each member being cemented together from two single lenses having opposite refractive power, said lens members having substantially the following approximate specifications:
References Cited (Backward Citations)
US1939098A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-08-23 | 1975-02-22 | 1975-08-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-08-23 | 1979-02-22 | 1979-08-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-08-23 | 1983-02-22 | 1983-08-24 | $7700.00 | Window Closed / Lapsed |