Patent US3757656A successfully refreshed from Google Patents.
US3757656A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Single lens reflex camera
Assignee: Minolta Co Ltd
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Filing: 1971-11-15
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Granted: 1973-09-11
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Expires: 1991-11-15
Abstract
Abstract A single lens reflex camera having a pentagonal prism view finder is provided with an additional prism disposed on the rooftype reflection surface of the pentagonal prism. The light rays from exposure condition information indicating devices such as a diaphragm opening indicator and a range finder may be caused to fall upon the pentagonal prism, through the additional prism. The light rays are reflected on the front lower reflection plane of said pentagonal prism which directs the rays to an eyepiece so that the exposure condition information is visible in the vision field of the finder.
Inventors
- 👤 Y Kuramoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 20:19
CPC Classifications
G; G03; G03B; G03B19/00; G03B19/02; G03B19/12; G03B17/00; G03B17/18; G03B17/20
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
132 words
A view finder for a single lens reflex camera comprising: a pentagonal prism having a bottom entrance surface, a roof-type reflecting surface where first and second reflections are formed at predetermined areas, a front lower reflecting surface, and an exit surface for transmitting picture image light rays; an objective lens for directing picture image light rays to fall upon the entrance surface of the pentagonal prism; and a second prism disposed on said roof-type reflecting surface for directing light rays from an exposure condition information indicator into said pentagonal prism through said roof-type reflecting surface, the second prism being disposed on an area of the roof-type surface outside the areas of the first and second reflections of the picture image light rays formed by the roof-type reflecting surface of said pentagonal prism.
Claim 2
Dependent Claim
132 words
A view finder for a single lens reflex camera comprising: a pentagonal prism having a bottom entrance surface, a roof-type reflecting surface where first and second reflections are formed at predetermined areas, a front lower reflecting surface, and an exit surface for transmitting picture image light rays; an objective lens for directing picture image light rays to fall upon the entrance surface of the pentagonal prism; and a second prism disposed on said roof-type reflecting surface for directing light rays from an exposure condition information indicator into said pentagonal prism through said roof-type reflecting surface, the second prism being disposed on an area of the roof-type surface outside the areas of the first and second reflections of the picture image light rays formed by the roof-type reflecting surface of said pentagonal prism.
Claim 3
Dependent Claim
43 words
A view finder as set forth in claim 1, wherein is included an exposure condition information indicator and an optical system for directing light rays from the exposure condition information indicator into the prism on said roof-type reflecting surface of said pentagonal prism.
Claim 4
Dependent Claim
21 words
A view finder as set forth in claim 2, wherein said indicator includes the position scale of a diaphragm adjusting member.
Claim 5
Dependent Claim
20 words
A view finder as set forth in claim 2, wherein said indicator includes a scale of a focus adjusting member.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-09-10 | 1977-03-12 | 1977-09-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-09-10 | 1981-03-12 | 1981-09-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-09-10 | 1985-03-12 | 1985-09-11 | $7700.00 | Window Closed / Lapsed |