US3758822A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Computer type flash apparatus with noise inhibiting quench circuit
Assignee: Rollei of America Inc
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Filing: 1972-04-20
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Granted: 1973-09-11
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Expires: 1992-04-20
Abstract
Abstract A computer type flash apparatus includes a switching device, a sensing transmitter and a flash device. The switching device is selectively operable for providing a contact closure to fire the flash device, which, in turn, produces light for the illumination of a scene to be photographed. The sensing transmitter provides a quench signal upon receipt of a predetermined amount of light from the scene. The quench signal is applied through a capacitor to the gate terminal of a silicon controlled rectifier (SCR) to trigger the SCR thereby actuating a quench circuit in the flash device. The operation of the quench circuit terminates the production of light by the flash device. A resistor is connected between the gate and cathode terminals of the SCR. When the flash device is fired, a signal representative thereof effects the appearance of a voltage across the resistor to inhibit noise signals from falsely triggering the SCR until the quench signal is generated by the sensing transmitter.
Inventors
- 👤 D Wilwerding
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 20:15
CPC Classifications
H; H05; H05B; H05B41/00; H05B41/14; H05B41/30; H05B41/32; H05B41/325
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
271 words
The combination comprising: control signal generating means for providing a control signal of a predetermined magnitude; first switching means connected to said control signal generating means, said first switching means being selectively operable for effecting a first change in magnitude of said control signal; light producing means operable to provide light for illuminating a scene; flash actuation means connecting said control signal generating means and said light producing means, said actuation means being responsive to said first change in magnitude of said control signal for actuating said light producing means; coupling means coupling said light producing means with said control signal generating means, said coupling means being responsive to an actuation of said light producing means for effecting a second change in magnitude of said control signal; light sensing means responsive to light received from said scene for effecting a third change in magnitude of said control signal upon receipt of a predetermined amount of said light received from said scene; quench control means operable for effectively terminating said light provided by said light producing means; second switching means actuated by said third change in magnitude of said control signal for effecting an operation of said quench control means; and signal responsive means connecting said second switching means with said control signal generating means, said signal responsive means being responsive to said second change in magnitude of said control signal for generating a swamping signal to effectively swamp the responsiveNess of said second switching means to spurious changes in said control signal, appearing between said second and third changes, of a magnitude less than the instantaneous magnitude of said swamping signal.
Claim 2
Dependent Claim
271 words
The combination comprising: control signal generating means for providing a control signal of a predetermined magnitude; first switching means connected to said control signal generating means, said first switching means being selectively operable for effecting a first change in magnitude of said control signal; light producing means operable to provide light for illuminating a scene; flash actuation means connecting said control signal generating means and said light producing means, said actuation means being responsive to said first change in magnitude of said control signal for actuating said light producing means; coupling means coupling said light producing means with said control signal generating means, said coupling means being responsive to an actuation of said light producing means for effecting a second change in magnitude of said control signal; light sensing means responsive to light received from said scene for effecting a third change in magnitude of said control signal upon receipt of a predetermined amount of said light received from said scene; quench control means operable for effectively terminating said light provided by said light producing means; second switching means actuated by said third change in magnitude of said control signal for effecting an operation of said quench control means; and signal responsive means connecting said second switching means with said control signal generating means, said signal responsive means being responsive to said second change in magnitude of said control signal for generating a swamping signal to effectively swamp the responsiveNess of said second switching means to spurious changes in said control signal, appearing between said second and third changes, of a magnitude less than the instantaneous magnitude of said swamping signal.
Claim 3
Dependent Claim
23 words
The combination as set forth in claim 1 wherein said swamping signal is of a varying time-magnitude relationship and of a predetermined duration.
Claim 4
Dependent Claim
63 words
The combination as set forth in claim 2 wherein said second switching means comprises a silicon controlled rectifier (SCR) having anode, cathode and gate terminals, and said first and second changes in magnitude of said control signal are in the form of decreases in potential, said third change in magnitude of said control signal being in the form of an increase in potential.
Claim 5
Dependent Claim
38 words
The combination as set forth in claim 3 wherein said signal responsive means comprises a capacitor connecting said control signal generating means with said SCR gate terminal and a resistor connected between said SCR gate and cathode terminals.
Claim 6
Dependent Claim
41 words
The combination as set forth in claim 4 wherein said signal responsive means further includes a diode connected in series with said resistor, the anode to cathode path of said diode being arranged between said SCR cathode and gate terminals, respectively.
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) | 1976-09-10 | 1977-03-12 | 1977-09-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-09-10 | 1981-03-12 | 1981-09-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-09-10 | 1985-03-12 | 1985-09-11 | $7700.00 | Window Closed / Lapsed |