Patent US3870402A successfully refreshed from Google Patents.
US3870402A
Expired / Lapsed
US
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Wide, angle, high aperture ratio, long back focus lens system
Assignee: Pentax Corp
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Filing: 1973-07-17
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Granted: 1975-03-11
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Expires: 1993-07-17
Abstract
Abstract A wide angle objective lens system of high aperture ratio and long back focus includes eight successively designated lens elements in which the sixth and seventh lens elements are cemented at their confronting surfaces to form a doublet and which satisfies the following conditions:
Inventors
- 👤 Yasuo Takahashi
- 👤 Sadao Okudaira
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 22:42
CPC Classifications
G; G02; G02B; G02B13/00; G02B13/04
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
73 words
A wide angle, high aperture ratio, long back focus lens system comprising eight successively designated lens elements in which the sixth and seventh lens elements are joined at their confronting faces to form a doublet, the lens system having the following dimensions and relationships, the lens faces being successively designated from the first to the fifteenth faces with the confronting faces of the sixth and seventh lenses defining a singly designated lens face:
Claim 2
Dependent Claim
73 words
A wide angle, high aperture ratio, long back focus lens system comprising eight successively designated lens elements in which the sixth and seventh lens elements are joined at their confronting faces to form a doublet, the lens system having the following dimensions and relationships, the lens faces being successively designated from the first to the fifteenth faces with the confronting faces of the sixth and seventh lenses defining a singly designated lens face:
Claim 3
Dependent Claim
73 words
A wide angle, high aperture ratio, long back focus lens system comprising eight successively designated lens elements in which the sixth and seventh lens elements are joined at their confronting faces to form a doublet, the lens system having the following dimensions and relationships, the lens faces being successively designated from the first to the fifteenth faces with the confronting faces of the sixth and seventh lenses defining a singly designated lens face:
Claim 4
Dependent Claim
73 words
A wide angle, high aperture ratio, long back focus lens system comprising eight successively designated lens elements in which the sixth and seventh lens elements are joined at their confronting faces to form a doublet, the lens system having the following dimensions and relationships, the lens faces being successively designated from the first to the fifteenth faces with the confronting faces of the sixth and seventh lenses defining a singly designated lens face:
Claim 5
Dependent Claim
73 words
A wide angle, high aperture ratIo, long back focus lens system comprising eight successively designated lens elements in which the sixth and seventh lens elements are joined at their confronting faces to form a doublet, the lens system having the following dimensions and relationships, the lens faces being successively designated from the first to the fifteenth faces with the confronting faces of the sixth and seventh lenses defining a singly designated lens face:
Claim 6
Dependent Claim
73 words
A wide angle, high aperture ratIo, long back focus lens system comprising eight successively designated lens elements in which the sixth and seventh lens elements are joined at their confronting faces to form a doublet, the lens system having the following dimensions and relationships, the lens faces being successively designated from the first to the fifteenth faces with the confronting faces of the sixth and seventh lenses defining a singly designated lens face:
References Cited (Backward Citations)
US3622227A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-03-10 | 1978-09-09 | 1979-03-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-10 | 1982-09-09 | 1983-03-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-10 | 1986-09-09 | 1987-03-11 | $7700.00 | Window Closed / Lapsed |