US3971046A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Systems for responding to non-uniform scene brightness
Assignee: Pentax Corp
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Filing: 1974-06-27
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Granted: 1976-07-20
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Expires: 1994-06-27
Abstract
Abstract A system for responding to non-uniform scene brightness. The system includes a plurality of photosensitive devices which are capable of receiving light from different parts of a scene while remaining static with respect thereto. Through an electrical connecting structure these photosensitive devices are all electrically connected with an output structure which will provide an output determined by at least one of a pair of the photosensitive devices which are respectively exposed to light of maximum and minimum brightness from the scene. The plurality of photosensitive devices provide inputs which vary according to a geometric progression in accordance with the variation in light brightness. The electrical connecting structure, however, changes the geometric progression in the variation of the inputs from the plurality of photosensitive devices to an arithmetic progression so that at the output device there is achieved an output which varies according to an arithmetic progression, in this way enabling the output to be used directly for photographic purposes.
Inventors
- 👤 Tsukumo Nobusawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 19:28
CPC Classifications
G; G01; G01J; G01J1/00; G01J1/42; G03; G03B; G03B7/00; G03B7/08; G03B7/081; G03B7/087
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
293 words
In a system for responding to non-uniform scene brightness, a plurality of identical photosensitive means for respectively receiving light from different parts of a scene, for respectively providing, from the received light, inputs which vary according to a geometric progression in accordance with variation in light brightness, and for providing at a pair of said photosensitive means, respectively, maximum and minimum inputs when the scene has light of non-uniform brightness to be received by the plurality of photosensitive means, output means for providing an output from at least one of said pair of photosensitive means, and electrical connecting means electrically connecting said plurality of photosensitive means with said output means for providing at said output means an output determined by said one of said pair of photosensitive means and for converting the geometric progression of said input of each photosensitive means into an arithmetic progression so that the output provided by said output means varies according to an arithmetic progression, said electrical connecting means including a timing circuit means having a resistor and capacitor connected in series with said capacitor of said timing circuit means having a charge which progressively changes during an interval when said plurality of photosensitive means respond to light from different parts of a scene, and said electrical connecting means further including a relay switch means operatively connected with said timing circuit means as well as with said plurality of photosensitive means for automatically opening said timing circuit means and terminating the change in the charge of said capacitor thereof in response to said light input of said one of said pair of photosensitive means, and the charge of said capacitor upon opening of said timing circuit means providing, at least in part, said output at said output means.
Claim 2
Dependent Claim
293 words
In a system for responding to non-uniform scene brightness, a plurality of identical photosensitive means for respectively receiving light from different parts of a scene, for respectively providing, from the received light, inputs which vary according to a geometric progression in accordance with variation in light brightness, and for providing at a pair of said photosensitive means, respectively, maximum and minimum inputs when the scene has light of non-uniform brightness to be received by the plurality of photosensitive means, output means for providing an output from at least one of said pair of photosensitive means, and electrical connecting means electrically connecting said plurality of photosensitive means with said output means for providing at said output means an output determined by said one of said pair of photosensitive means and for converting the geometric progression of said input of each photosensitive means into an arithmetic progression so that the output provided by said output means varies according to an arithmetic progression, said electrical connecting means including a timing circuit means having a resistor and capacitor connected in series with said capacitor of said timing circuit means having a charge which progressively changes during an interval when said plurality of photosensitive means respond to light from different parts of a scene, and said electrical connecting means further including a relay switch means operatively connected with said timing circuit means as well as with said plurality of photosensitive means for automatically opening said timing circuit means and terminating the change in the charge of said capacitor thereof in response to said light input of said one of said pair of photosensitive means, and the charge of said capacitor upon opening of said timing circuit means providing, at least in part, said output at said output means.
Claim 3
Dependent Claim
36 words
The combination of claim 1 and wherein said electrical connecting means includes a plurality of diodes electrically connected in series with said plurality of photosensitive means, respectively, for converting the geometric progression to an arithmetic progression.
Claim 4
Dependent Claim
35 words
The combination of claim 1 and wherein said electrical connecting means includes a single diode connected between said plurality of photosensitive means and said output means for converting the geometric progression into an arithmetic progression.
Claim 5
Dependent Claim
26 words
The combination of claim 1 and wherein said output means includes an indicating means for directly indicating a light value to be used for photographing purposes.
Claim 6
Dependent Claim
61 words
The combination of claim 1 and wherein said output means provides outputs from both of said pair of photosensitive means and also is operatively connected with both of said pair of photosensitive means through said electrical connecting means for providing an indication of a light value range between the pair of outputs derived from both of said pair of photosensitive means.
Claim 7
Dependent Claim
52 words
The combination of claim 1 and wherein said output means is electrically connected through said electrical connecting means with said plurality of photosensitive means for providing outputs from both of said pair of photosensitive means as well as for providing an intermediate output between the outputs from both of said photosensitive means.
Claim 8
Dependent Claim
23 words
The combination of claim 6 and wherein said output means includes means for providing light value outputs to be used for photographic purposes.
Claim 9
Dependent Claim
40 words
The combination of claim 6 and including a shutter-closing circuit means for determining exposure time electrically connected with that part of said output means which provides said intermediate output for automatically determining exposure time in accordance with said intermediate output.
Claim 10
Dependent Claim
41 words
The combination of claim 6 and including an automatic diaphragm-adjusting circuit means electrically connected with that part of said output means which provides an intermediate output for automatically determining the exposure aperture of a camera in accordance with said intermediate output.
Claim 11
Dependent Claim
117 words
The combination of claim 6 and wherein said output means included for determining said intermediate output a differential circuit having a pair of transistors having emitters connected to each other and also having collectors, means connected between said collectors of said transistors for determining said intermediate output, said transistors also having bases, and a pair of variable resistors respectively connected to said bases of said transistors, so that when one of said variable resistors is set in accordance with film speed and the other of said variable resistors is set in accordance with one of the factors of exposure time and diaphragm aperture, said intermediate output will have a value corresponding to the other of said factors.
Claim 12
Dependent Claim
32 words
The combination of claim 1 and wherein said electrical connecting means provides at said capacitor of said timing circuit means thereof an increasing charge which is terminated by said relay switch means.
Claim 13
Dependent Claim
32 words
The combination of claim 1 and wherein said electrical connecting means provides at said capacitor of said timing circuit means thereof a decreasing charge which is terminated by said relay switch 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) | 1979-07-20 | 1980-01-19 | 1980-07-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-07-20 | 1984-01-19 | 1984-07-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-07-20 | 1988-01-19 | 1988-07-20 | $7700.00 | Window Closed / Lapsed |