US3912968A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Flash tube discharge-producing circuit
Assignee: Canon Inc
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Filing: 1973-08-03
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Granted: 1975-10-14
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Expires: 1993-08-03
Abstract
Abstract A flash tube discharge-promoting circuit comprising an auxiliary capacitor and a thyristor is incorporated in a flash producing circuit so that, upon the advent of a trigger impulse to the trigger electrode of a discharge flash tube, an instantaneous potential of the charge previously stored in the auxiliary capacitor is added in the negative direction to the negative potential of the charge stored in the flash capacitor to produce a flash impulse. The use of an auxiliary capacitor is essential to achieving the superior operating characteristics of the flash discharge-producing circuit to which this invention relates, because it permits the circuit to be designed with a relatively low voltage power source.
Inventors
- 👤 Zenzo Nakamura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 05:49
CPC Classifications
H; H05; H05B; H05B41/00; H05B41/14; H05B41/30; H05B41/32
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
152 words
A flash discharge-producing device comprising: a flash lighting power source means, a flash tube for producing a quantity of light energy, a main capacitor connected to said power source for storing electric energy to be transLated into light energy in said flash tube, a one-directionally conducting means arranged in the current supply path between the main capacitor and the flash tube, an auxiliary capacitor, one terminal of which is connected to the contact between the flash tube and the one-directionally conducting means, the other being connected to said power source means to store electric energy to be translated to light energy within the flash tube at an initial period of emission of said flash tube, a flash tube trigger circuit for applying a trigger voltage to the flash tube in order to initiate the flash discharge thereof, being associated with a trigger switch arranged in the charge-delivering path of said auxiliary capacitor.
Claim 2
Dependent Claim
152 words
A flash discharge-producing device comprising: a flash lighting power source means, a flash tube for producing a quantity of light energy, a main capacitor connected to said power source for storing electric energy to be transLated into light energy in said flash tube, a one-directionally conducting means arranged in the current supply path between the main capacitor and the flash tube, an auxiliary capacitor, one terminal of which is connected to the contact between the flash tube and the one-directionally conducting means, the other being connected to said power source means to store electric energy to be translated to light energy within the flash tube at an initial period of emission of said flash tube, a flash tube trigger circuit for applying a trigger voltage to the flash tube in order to initiate the flash discharge thereof, being associated with a trigger switch arranged in the charge-delivering path of said auxiliary capacitor.
Claim 3
Dependent Claim
50 words
A flash discharge-producing device according to claim 1, wherein said trigger circuit is further provided with a trigger capacitor to which said power source means is connected to charge it, and the charge-delivering path of said trigger capacitor is provided with said trigger switch and a trigger transformer arranged therein.
Claim 4
Dependent Claim
28 words
A flash discharge producing device according to claim 1, wherein said one-directionally conducting means is a thyristor having a gate to which a non-conducting signal may be applied.
Claim 5
Dependent Claim
87 words
A flash discharge-producing device according to claim 1, wherein said trigger circuit is provided with; a trigger transformer having a primary winding and secondary winding, the primary winding being connected to said trigger switch, and the secondary winding being connected to said trigger switch, and the secondary winding being connected to the trigger electrode of the flash tube, and resistor means connected in parallel to said one-directionally conducting means, through which the primary winding of the trigger transformer forms a closed loop along with the trigger switch.
Claim 6
Dependent Claim
59 words
A flash discharge device according to claim 3 wherein said trigger circuit is provided with; a subsidiary condenser connected both to the power source and to the other terminal of the auxiliary capacitor, and a subsidiary condenser short circuit having said trigger switch and resistor means incorporated therein, said resistor means being connected to the gate of said thyristor.
Claim 7
Dependent Claim
63 words
A flash discharge-producing device according to claim 5, wherein said trigger circuit is further provided with a thyristor, a trigger condenser, and a trigger transformer of which the primary winding forms a closed circuit along with said thyristor and having a secondary winding connected to the trigger electrode of the flash tube; and said thyristor has a gate connected to said resistor means.
Claim 8
Dependent Claim
34 words
An electric flash device according to claim 1 wherein said auxiliary capacitor further comprise circuit means for coupling the electrical energy stored in said auxiliary capacitor to said main capacitor through said flash tube.
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) | 1978-10-13 | 1979-04-14 | 1979-10-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-10-13 | 1983-04-14 | 1983-10-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-10-13 | 1987-04-14 | 1987-10-14 | $7700.00 | Window Closed / Lapsed |