Patent US5311244A successfully refreshed from Google Patents.
US5311244A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Exposure control device for a camera
Assignee: Minolta Co Ltd
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Filing: 1993-09-14
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Granted: 1994-05-10
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Expires: 2013-09-14
Abstract
Abstract An exposure control device for a camera comprising; first means for measuring light from a central area of an object field, said first measuring means including a plurality of means for receiving light from different portions within the central area, respectively; second means for measuring light from a surrounding area other than the central area, the surrounding area being greater than each portion within the central area; means for selecting between a first exposure control mode and a second exposure control mode; and means for controlling exposure in accordance with one of said plurality of receiving means in said first exposure control mode, and in accordance with all of said plurality of receiving means and said second measuring means in said second exposure control mode.
Inventors
- 👤 Masaaki Nakai
- 👤 Shuji Izumi
- 👤 Akihiko Fujino
- 👤 Nobuyuki Taniguchi
- 👤 Toshio Yamaki
- 👤 Hiromu Mukai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 20:41
CPC Classifications
G; G03; G03B; G03B7/00; G03B7/28; G03B7/08; G03B7/091; G03B7/093; G03B7/16
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
111 words
An exposure control device for a camera operable in a flash photography mode, comprising: first means for measuring ambient light from a central area of an object field; second means for measuring ambient light from another area of the object field which is outside of the central area; means responsive to said first and second measuring means for detecting a back light condition; means for controlling an exposure amount on the basis of the measured ambient light of said other area, as measured by said second measuring means, when said detecting means detects the back light condition; and means for controlling a flash light emission independently of said second measuring means.
Claim 2
Dependent Claim
111 words
An exposure control device for a camera operable in a flash photography mode, comprising: first means for measuring ambient light from a central area of an object field; second means for measuring ambient light from another area of the object field which is outside of the central area; means responsive to said first and second measuring means for detecting a back light condition; means for controlling an exposure amount on the basis of the measured ambient light of said other area, as measured by said second measuring means, when said detecting means detects the back light condition; and means for controlling a flash light emission independently of said second measuring means.
Claim 3
Dependent Claim
50 words
The exposure control device according to claim 1, wherein said detecting means includes means for comparing a light measurement from said first measuring means with that from said second measuring means to determine a difference, and means for deciding the back light condition when the difference exceeds a predetermined level.
Claim 4
Dependent Claim
19 words
The exposure control system of claim 1 wherein said other area of the object field surrounds the central area.
Claim 5
Dependent Claim
50 words
The exposure control device according to claim 1, further comprising means for storing the amount of ambient light measured by said second measuring means, wherein said exposure controlling means includes means for calculating exposure time and aperture value based on the amount of ambient light stored by said storing means.
Claim 6
Dependent Claim
130 words
An exposure control device for a camera operable in a flash photography mode, comprising: first means for measuring ambient light from a central area of an object field; second means for measuring ambient light from another area of the object field which is outside of the central area; means responsive to said first and second measuring means for detecting a back light condition; means for controlling exposure based on the ambient light from the area outside of the central area, as measured by said second measuring means, when said detecting means detects the back light condition; and means for controlling a flash light emission independently of the exposure control by said exposure controlling means that is based on the measured ambient light from the area outside of the central area.
Claim 7
Dependent Claim
130 words
An exposure control device for a camera operable in a flash photography mode, comprising: first means for measuring ambient light from a central area of an object field; second means for measuring ambient light from another area of the object field which is outside of the central area; means responsive to said first and second measuring means for detecting a back light condition; means for controlling exposure based on the ambient light from the area outside of the central area, as measured by said second measuring means, when said detecting means detects the back light condition; and means for controlling a flash light emission independently of the exposure control by said exposure controlling means that is based on the measured ambient light from the area outside of the central area.
Claim 8
Dependent Claim
52 words
The exposure control device according to claim 5, wherein said flash light emission controlling means includes third means for measuring flash light reflected by an object and means for interrupting the flash light emission when an amount of the reflected flash light measured by said third measuring means reaches a predetermined level.
Claim 9
Dependent Claim
47 words
The exposure control device according to claim 5, further wherein said exposure controlling means controls exposure based on both the measured ambient light from the central area and from the area outside of the central area when said detecting means does not detect the back light condition.
Claim 10
Dependent Claim
37 words
The exposure control device according to claim 5, wherein said flash light controlling means controls flash light emission in accordance with the measured amount of light from the central area as measured by said first measuring means.
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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) | 1997-05-09 | 1997-11-08 | 1998-05-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-05-09 | 2001-11-08 | 2002-05-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-05-09 | 2005-11-08 | 2006-05-10 | $7700.00 | Window Closed / Lapsed |