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US4213682A
Expired / Lapsed
US
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Programmed exposure control system for a camera
Assignee: Minolta Co Ltd
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Filing: 1978-12-12
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Granted: 1980-07-22
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Expires: 1998-12-12
Abstract
Abstract In a photographic camera having programmed automatic exposure control, a light measuring output is produced by measuring scene light and an exposure value signal is generated in response to the light measuring output. A time value and aperture value signal are automatically varied as a function of the changes in the exposure value signal, which function is adapted to be altered in a predetermined manner by the change in the exposure value signal. The aperture size is determined in response to the size in the aperture value signal and the exposure time is determined in accordance with the time value signal.
Inventors
- 👤 Seiji Yamada
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 21:29
CPC Classifications
G; G03; G03B; G03B7/00; G03B7/08; G03B7/081; G03B7/087; G03B7/089
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
125 words
A photographic camera capable of programmed automatic exposure control comprising: means for measuring light to produce a light measuring output; means for producing an exposure control signal in response to the light measuring output; means for automatically varying both the time value signal and aperture value signal as a first function of the magnitude of the exposure control signal when said magnitude is in a first range of exposure control signal magnitudes, and as a second function of the magnitude of the exposure control signal when said magnitude is in a second range of exposure control signal magnitudes; means for determining the aperture size in response to the aperture value signal; and means for determining the exposure time in response to said time value signal.
Claim 2
Dependent Claim
125 words
A photographic camera capable of programmed automatic exposure control comprising: means for measuring light to produce a light measuring output; means for producing an exposure control signal in response to the light measuring output; means for automatically varying both the time value signal and aperture value signal as a first function of the magnitude of the exposure control signal when said magnitude is in a first range of exposure control signal magnitudes, and as a second function of the magnitude of the exposure control signal when said magnitude is in a second range of exposure control signal magnitudes; means for determining the aperture size in response to the aperture value signal; and means for determining the exposure time in response to said time value signal.
Claim 3
Dependent Claim
28 words
A photographic camera as in claim 1, wherein said second range of exposure control signal magnitude is lower than the exposure control signal magnitudes in said first range.
Claim 4
Dependent Claim
35 words
A photographic camera as in claim 2, wherein the ratio of change of said time value signal to that of said aperture value signal is greater in said first function than in said second function.
Claim 5
Dependent Claim
33 words
A photographic camera as in claim 3, wherein said first function is a first linear function with a first constant and the second function is a second linear function with a second constant.
Claim 6
Dependent Claim
45 words
A photographic camera as in claim 4 further comprising first means for determining the first linear function, second means for determining the second linear function, and means for automatically selecting one of said first and second determining means in response to the exposure control signal.
Claim 7
Dependent Claim
50 words
A photographic camera as in claim 3, wherein said automatically varying means includes means for storing various program signals corresponding to various magnitudes of the exposure control signal, and means for selecting one of said program signals in response to the exposure control signal generated by said means for producing.
Claim 8
Dependent Claim
63 words
A photographic camera as in claim 3, wherein said light mesuring means is adapted to produce the light measuring output by means of fully open aperture measurement, and said means for producing includes means for setting the fully open aperture size to produce the exposure control signal and means to compensate the exposure control signal to account for different fully open aperture sizes.
Claim 9
Dependent Claim
44 words
A photographic camera as in claim 3, wherein said automatically varying means includes means for producing said aperture value signal as a function of said exposure control signal, and means for producing said time value signal as a function of said aperture value signal.
Claim 10
Dependent Claim
93 words
A photographic camera capable of programmed automatic exposure control comprising: means for measuring light through the diaphragm aperture to produce a light measuring output; means for producing an exposure control signal in response to the light measuring output; first means for generating a first signal from said exposure control signal and a first reference signal; second means for generating a second signal from said exposure control signal and a second reference signal; means for selecting one of said first and second signals in accordance with said exposure control signal to control the exposure.
Claim 11
Dependent Claim
93 words
A photographic camera capable of programmed automatic exposure control comprising: means for measuring light through the diaphragm aperture to produce a light measuring output; means for producing an exposure control signal in response to the light measuring output; first means for generating a first signal from said exposure control signal and a first reference signal; second means for generating a second signal from said exposure control signal and a second reference signal; means for selecting one of said first and second signals in accordance with said exposure control signal to control the exposure.
Claim 12
Dependent Claim
41 words
A photographic camera as in claim 9 further comprising means for determining an aperture size of the diaphragm aperture as a function of a difference between said light measuring output and the selected one of said first and second dividing signals.
Claim 13
Dependent Claim
27 words
A photographic camera as in claim 10 further comprising means for determining the exposure time in response to the light measuring signal with the diaphragm aperture determined.
Claim 14
Dependent Claim
52 words
A photographic camera as in claim 9 wherein said first means includes a first means for dividing said exposure control signal and said first reference signal at a first ratio, and said second means includes second means for dividing said exposure control signal and said second reference signal at a second ratio.
Claim 15
Dependent Claim
114 words
A photographic camera capable of programmed automatic exposure control comprising: means for measuring light through the diaphragm aperture to produce a light measuring output; means for producing an exposure control signal in response to the light measuring output; means for converting said exposure control signal into a digital exposure control signal; means for selecting one of a plurality of digital program signals stored therein in response to said digital exposure control signal; means for converting the selected one of said digital program signals into an analog program signal; and means for determining the aperture size of the diaphragm aperture in response to a difference between said light measuring output and said analog program signal.
Claim 16
Dependent Claim
114 words
A photographic camera capable of programmed automatic exposure control comprising: means for measuring light through the diaphragm aperture to produce a light measuring output; means for producing an exposure control signal in response to the light measuring output; means for converting said exposure control signal into a digital exposure control signal; means for selecting one of a plurality of digital program signals stored therein in response to said digital exposure control signal; means for converting the selected one of said digital program signals into an analog program signal; and means for determining the aperture size of the diaphragm aperture in response to a difference between said light measuring output and said analog program signal.
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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) | 1983-07-22 | 1984-01-21 | 1984-07-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-07-22 | 1988-01-21 | 1988-07-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-07-22 | 1992-01-21 | 1992-07-22 | $7700.00 | Window Closed / Lapsed |