US3742828A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Camera having means for computing a flash guide number
Assignee: ASAKI KOGAKU KK
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Filing: 1972-01-26
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Granted: 1973-07-03
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Expires: 1992-01-26
Abstract
Abstract A camera which is capable of automatically computing a flash guide number. The camera has electronic input structure connected electrically with a computing structure for supplying to the latter signals in accordance with the APEX system and corresponding to a selected aperture setting, a selected distance setting, and a selected film speed setting. The computing structure computes a flash guide number in accordance with these signals. An electrical flash unit is provided for providing flash illumination, and the flash unit is electrically connected with the computing structure so as to determine the amount of flash illumination in accordance with the flash guide number which is computed by the computing structure.
Inventors
- 👤 T Nakajima
- 👤 C Mori
- 👤 M Marui
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 06:27
CPC Classifications
G; G03; G03B; G03B7/00; G03B7/16; H; H05; H05B; H05B41/00; H05B41/14; H05B41/30; H05B41/32
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
172 words
In a camera, electrical computing means for computing a flash guide number, electronic input means connected electrically with said computing means for supplying to the latter signals in the form of electrical quantities adjusted to conform to the APEX system and respectively corresponding to a selected aperture setting, a selected distance setting, and a selected film speed setting, said computing means being electrically connected with said input means for receiving therefrom on the one hand a signal corresponding to said distance setting and on the other hand a signal corresponding to the difference between said film speed setting and said aperture setting, said computing means being electrically connected with said input means for computing the difference between the latter signals received therefrom for computing a flash guide number in accordance with said signals, and electronic flash means for providing flash illumination, said electronic flash means being electrically connected with said computing means for determining the amount of the flash illumination in accordance with the flash guide number computed by said computing means.
Claim 2
Dependent Claim
172 words
In a camera, electrical computing means for computing a flash guide number, electronic input means connected electrically with said computing means for supplying to the latter signals in the form of electrical quantities adjusted to conform to the APEX system and respectively corresponding to a selected aperture setting, a selected distance setting, and a selected film speed setting, said computing means being electrically connected with said input means for receiving therefrom on the one hand a signal corresponding to said distance setting and on the other hand a signal corresponding to the difference between said film speed setting and said aperture setting, said computing means being electrically connected with said input means for computing the difference between the latter signals received therefrom for computing a flash guide number in accordance with said signals, and electronic flash means for providing flash illumination, said electronic flash means being electrically connected with said computing means for determining the amount of the flash illumination in accordance with the flash guide number computed by said computing means.
Claim 3
Dependent Claim
63 words
The combination of claim 1 and wherein an electronic shutter-operating means operates a shutter of the camera to determine the exposure time, and electronic control means electrically connected with said electronic shutter-operating means for controlling the latter, and that part of said electronic input means which provides signals according to the selected aperture and film speed settings forming part of said shutter-control means.
Claim 4
Dependent Claim
30 words
The combination of claim 2 and wherein said shutter-control means includes an electronic means for providing a signal according to the intensity of light at the object which is photographed.
Claim 5
Dependent Claim
135 words
The combination of claim 3 and wherein a switch means is electrically connected on the one hand with the electronic means for providing a signal according to the light intensity at the object which is to be photographed and on the other hand with that part of the electronic input means which provides a signal according to the selected distance for rendering the latter part of said electronic input means operative and the electronic means for providing a signal according to light intensity inoperative when an exposure is to be made with flash illumination and for rendering that part of said electronic input means which provides a signal according to distance inoperative and said electronic means for providing a signal according to light intensity operative when an exposure is to be made without flash illumination.
References Cited (Backward Citations)
US3545858A
Cited
US3611159A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-07-02 | 1977-01-01 | 1977-07-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-02 | 1981-01-01 | 1981-07-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-02 | 1985-01-01 | 1985-07-03 | $7700.00 | Window Closed / Lapsed |