Patent US3583785A successfully refreshed from Google Patents.
US3583785A
Expired / Lapsed
US
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Positive optical system
Assignee: Bell and Howell Co
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Filing: 1969-09-02
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Granted: 1971-06-08
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Expires: 1989-09-02
Abstract
Abstract A positive optical system having four optical elements, each of which is aspheric and arranged in pairs with the elements of the pairs being of the same biconvex configuration.
Inventors
- 👤 Jack B Boardman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 12:20
CPC Classifications
G; G02; G02B; G02B23/00; G02B23/14; G02B3/00; G02B3/02; G02B3/04
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
9 words
A positive optical system having substantially the following specification:
Claim 2
Dependent Claim
9 words
A positive optical system having substantially the following specification:
References Cited (Backward Citations)
GB606065A
Cited
US2955512A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-06-07 | 1974-12-07 | 1975-06-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-06-07 | 1978-12-07 | 1979-06-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-06-07 | 1982-12-07 | 1983-06-08 | $7700.00 | Window Closed / Lapsed |