US3872484A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Metering device for a single lens reflex camera
Assignee: Canon Inc
•
Filing: 1974-05-20
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Granted: 1975-03-18
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Expires: 1994-05-20
Abstract
Abstract In a single lens reflex camera, a metering device comprises a metering element provided on the back side of a movable mirror so that, in raised position of the mirror, light passed through the picture-taking lens of the camera to the surface of a shutter curtain or of a photographic film and reflected by such surface may be received by the metering element to determine the exposure without the incident light from the picture-taking lens being directly passed to the metering element.
Inventors
- 👤 Teiji Hashimoto
- 👤 Takehiko Kiyohara
- 👤 Takashi Uchiyama
- 👤 Tokuichi Tsunekawa
- 👤 Masamichi Kakunodate
- 👤 Soichi Nakamoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 08:27
CPC Classifications
G; G03; G03B; G03B19/00; G03B19/02; G03B19/12; G03B7/00; G03B7/08; G03B7/099; G03B7/0993; G03B7/0997; G03B7/09971; G03B7/09973; G03B7/09974; G03B7/09976
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
108 words
A metering device for a single lens reflex camera having a movable mirror therewithin, said device comprising a metering element held on the back side of said movable mirror, and an incident light direction restricting structure formed on the light-sensing surface of said metering element, said restricting structure being inclined with respect to the light-sensing surface of said metering element so that it may intercept direct light from the picture-taking lenses of the camera in raised raised position of said movable mirror so as to permit only the reflected light from the surface of a film or of a shutter curtain to be passed to said metering element.
Claim 2
Dependent Claim
108 words
A metering device for a single lens reflex camera having a movable mirror therewithin, said device comprising a metering element held on the back side of said movable mirror, and an incident light direction restricting structure formed on the light-sensing surface of said metering element, said restricting structure being inclined with respect to the light-sensing surface of said metering element so that it may intercept direct light from the picture-taking lenses of the camera in raised raised position of said movable mirror so as to permit only the reflected light from the surface of a film or of a shutter curtain to be passed to said metering element.
Claim 3
Dependent Claim
37 words
A metering device according to claim 1, further comprising means for permitting the output terminals of said metering element to be led out through a pivot shaft for said movable mirror toward the body of the camera.
Claim 4
Dependent Claim
34 words
A metering device according to claim 1, wherein light-transmitting portions are formed in the surface of said movable mirror and a metering element is provided for sensing the light passed through said transmitting portions.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-03-17 | 1978-09-16 | 1979-03-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-17 | 1982-09-16 | 1983-03-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-17 | 1986-09-16 | 1987-03-18 | $7700.00 | Window Closed / Lapsed |