Patent US4571050A successfully refreshed from Google Patents.
US4571050A
Expired / Lapsed
US
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Light measuring device for camera
Assignee: Canon Inc
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Filing: 1984-05-17
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Granted: 1986-02-18
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Expires: 2004-05-17
Abstract
Abstract A light measuring device for a camera has a light receiving photo-sensitive element, the light receiving surface of which is divided at least into two regions including a center part and a peripheral part and a diffusing member which is disposed in front of the photo-sensitive element and is arranged to have a diffusing surface formed solely in the peripheral area thereof. The light measuring operation of the device is arranged to be shiftable between one mode in which light measurement is carried out solely through the center part of the light receiving surface of the photo-sensitive element and another mode in which light measurement is carried out approximately through the whole light receiving surface.
Inventors
- 👤 Kikuo Momiyama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 11:21
CPC Classifications
G; G03; G03B; G03B7/00; G03B7/08; G03B7/099; G03B7/0993; G03B7/0997; G03B7/09979
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
64 words
A light measuring device for a camera arranged to permit shifting of a photometric range thereof, comprising: a photo-sensitive element which is divided into two regions including a center part and a peripheral part; and a diffusing member divided into a center part and a peripheral part which are of different diffusing characteristics, said diffusing member being disposed in front of said photosensitive element.
Claim 2
Dependent Claim
64 words
A light measuring device for a camera arranged to permit shifting of a photometric range thereof, comprising: a photo-sensitive element which is divided into two regions including a center part and a peripheral part; and a diffusing member divided into a center part and a peripheral part which are of different diffusing characteristics, said diffusing member being disposed in front of said photosensitive element.
Claim 3
Dependent Claim
30 words
A light measuring device according to claim 1, wherein said diffusing member has said center part arranged to be transparent and said peripheral part formed to be a diffusing surface.
Claim 4
Dependent Claim
32 words
A light measuring device according to claim 2, wherein the area of the center part of said diffusing member is larger than the area of the center part of said photo-sensitive element.
Claim 5
Dependent Claim
21 words
A light measuring device according to claim 1, wherein a light receiving lens is disposed in front of said diffusing member.
Claim 6
Dependent Claim
49 words
A light measuring device according to claim 1, wherein a triangular prism which has a slanting surface arranged to be a reflection surface is disposed in front of said photo-sensitive element; and said diffusing member is formed on at least one of the transmissive surfaces of said triangular prism.
Claim 7
Dependent Claim
35 words
A light measuring device according to claim 5, wherein a light receiving lens is disposed at a transmissive surface of said triangular prism other than the transmissive surface on which said diffusing member is formed.
Claim 8
Dependent Claim
51 words
A light measuring device according to claim 1, in which the size of said center part of said diffusing member is smaller than the size of said center part of said sensitive element, and said diffusing member is retracted out of the optical path at the time of partial light measurement.
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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) | 1989-02-17 | 1989-08-19 | 1990-02-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-02-17 | 1993-08-19 | 1994-02-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-02-17 | 1997-08-19 | 1998-02-18 | $7700.00 | Window Closed / Lapsed |