Patent US4437741A successfully refreshed from Google Patents.
US4437741A
Expired / Lapsed
US
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Light measuring device for a single lens reflex camera
Assignee: Canon Inc
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Filing: 1982-07-20
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Granted: 1984-03-20
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Expires: 2002-07-20
Abstract
Abstract A light measuring device for a single lens reflex camera provided with an auxiliary mirror for light measurement behind the movable mirror is disclosed. The reflection surface of the auxiliary mirror of said light measuring device is divided into a plurality of regions, and reflected light beams from the respective regions proceed in different directions from each other. Either one or both of the light beams reflected from one region and the beam reflected from the other region is or are selectively directed to a light sensitive element by a light beam selecting member.
Inventors
- 👤 Yasuhisa Sato
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 15:54
CPC Classifications
G; G03; G03B; G03B7/00; G03B7/08; G03B7/099; G03B7/0993; G03B7/0997; G03B7/09971; G03B7/09972
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
106 words
A light measuring device for a single lens reflex camera having a swinging mirror, comprising: (a) light sensitive means; (b) an auxiliary mirror positioned behind said swinging mirror to conduct a light beam passed through said swinging mirror to said light sensitive means, the reflection surface of said auxiliary mirror being divided into a plurality of regions and being shaped such that said light beam after reflection from the regions is divided into respective parts which go to different directions from each other; and (c) light beam selecting means for conducting one of the light beams from said plurality of regions to said light sensitive means.
Claim 2
Dependent Claim
106 words
A light measuring device for a single lens reflex camera having a swinging mirror, comprising: (a) light sensitive means; (b) an auxiliary mirror positioned behind said swinging mirror to conduct a light beam passed through said swinging mirror to said light sensitive means, the reflection surface of said auxiliary mirror being divided into a plurality of regions and being shaped such that said light beam after reflection from the regions is divided into respective parts which go to different directions from each other; and (c) light beam selecting means for conducting one of the light beams from said plurality of regions to said light sensitive means.
Claim 3
Dependent Claim
29 words
A light measuring device according to claim 1, wherein said light beam selecting means includes a shielding plate for selectively shielding the light beams from said plurality of regions.
Claim 4
Dependent Claim
32 words
A light measuring device according to claim 2, wherein said shielding plate is positioned in a space between said auxiliary mirror and said light sensitive means and rotates in an arcuate path.
Claim 5
Dependent Claim
38 words
A light measuring device according to claim 1, wherein said light beam selecting means includes a member coupled to said light sensitive means to selectively change the direction of the light receiving surface of said light sensitive means.
Claim 6
Dependent Claim
135 words
A light measuring device for a single lens reflex camera having a swinging mirror, comprising: (a) light sensitive means; (b) an auxiliary mirror positioned behind said swinging mirror to conduct a light beam passed through said swinging mirror to said light sensitive means, the reflection surface of said auxiliary mirror being divided into a plurality of regions and being shaped such that said light beam after reflection from the regions is divided into respective parts which go to different directions from each other; and (c) means movable selectively to a 1st position where at least two light beams from said plurality of regions are conducted to said light sensitive means at a time and a 2nd position where one of the light beams from said plurality of regions is conducted to said light sensitive means.
Claim 7
Dependent Claim
135 words
A light measuring device for a single lens reflex camera having a swinging mirror, comprising: (a) light sensitive means; (b) an auxiliary mirror positioned behind said swinging mirror to conduct a light beam passed through said swinging mirror to said light sensitive means, the reflection surface of said auxiliary mirror being divided into a plurality of regions and being shaped such that said light beam after reflection from the regions is divided into respective parts which go to different directions from each other; and (c) means movable selectively to a 1st position where at least two light beams from said plurality of regions are conducted to said light sensitive means at a time and a 2nd position where one of the light beams from said plurality of regions is conducted to said light sensitive means.
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) | 1987-03-20 | 1987-09-19 | 1988-03-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-03-20 | 1991-09-19 | 1992-03-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-03-20 | 1995-09-19 | 1996-03-20 | $7700.00 | Window Closed / Lapsed |