Patent US3552829A successfully refreshed from Google Patents.
US3552829A
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US
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Photographic gauss type objective
Assignee: Ernst Leitz Wetzlar GmbH
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Filing: 1968-12-02
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Granted: 1971-01-05
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Expires: 1988-12-02
Abstract
Abstract A PHOTOGRAPHIC GAUSS TYPE OBJECTIVE IS DISCLOSED WHICH COMPRISES IN THE DIRECTION OF LIGHT TRAVEL THREE SINGLET LENS MEMBERS IN FRONT OF THE OBJECTIVE DIAPHRAGM AND A CEMENTED DOUBLE LENS MEMBER FOLLOWED BY TWO SINGLET LENS MEMBERS BEHIND THE DIAPHRAGM. THE RELATIVE APERTURE IS AT LEAST AS GREAT AS F:1.4, WHILE THE BACK FOCAL DISTANCE IS GREATER THAN 70% OF THE OBJECTIVE''S FOCAL LENGTH, AND THE FIELD ANGLE IS ABOUT $20*.
Inventors
- 👤 Heinz Marquardt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 14:11
CPC Classifications
G; G02; G02B; G02B13/00
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-01-04 | 1974-07-06 | 1975-01-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-01-04 | 1978-07-06 | 1979-01-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-01-04 | 1982-07-06 | 1983-01-05 | $7700.00 | Window Closed / Lapsed |