Flash apparatus and camera having the flash apparatus
First Claim
1. A flash apparatus comprising:
- a) a voltage boosting circuit having a transformer for boosting a battery voltage;
b) a main capacitor to be charged by said voltage boosting circuit; and
c) a control circuit for controlling starting and stopping of said voltage boosting circuit, wherein, when an oscillation of said voltage boosting circuit is stopped before said control circuit stops said voltage boosting circuit, said control circuit starts said voltage boosting circuit.
1 Assignment
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Accused Products
Abstract
In a flash apparatus, when it is determined that the oscillation of a voltage boosting circuit is stopped before it is controlled so as to stop, it is possible to continuously charge a voltage to a main capacitor by causing the voltage boosting circuit to continue oscillation by providing a control circuit for oscillating the voltage boosting circuit again. Further, the flash apparatus includes a charged current detecting circuit for detecting the current charged in a main capacitor using an auxiliary power source as a power source. The charged current detecting circuit is simply arranged with a passive element for bypassing a part of the current charged in the main capacitor from a loop through the above-mentioned auxiliary power source.
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Citations
18 Claims
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1. A flash apparatus comprising:
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a) a voltage boosting circuit having a transformer for boosting a battery voltage;
b) a main capacitor to be charged by said voltage boosting circuit; and
c) a control circuit for controlling starting and stopping of said voltage boosting circuit, wherein, when an oscillation of said voltage boosting circuit is stopped before said control circuit stops said voltage boosting circuit, said control circuit starts said voltage boosting circuit. - View Dependent Claims (9, 10, 11, 12, 13, 15, 17, 18)
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2. A flash apparatus comprising:
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a) a voltage boosting circuit having a transformer for boosting a battery voltage;
b) a main capacitor to be charged by said voltage boosting circuit;
c) a voltage detecting circuit for detecting a voltage of said main capacitor;
d) a control circuit for controlling starting and stopping of said voltage boosting circuit; and
e) an oscillation detecting circuit for detecting an oscillating state of said voltage boosting circuit, wherein, when said oscillation detecting circuit detects an oscillation stopping state of said voltage boosting circuit during a predetermined period of time before said control circuit stops said voltage boosting circuit, said control circuit starts said voltage boosting circuit. - View Dependent Claims (3, 4, 5, 6, 7, 8)
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14. A flash apparatus comprising:
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a) a voltage boosting circuit having a transformer for boosting a battery voltage;
b) a main capacitor to be charged by said voltage boosting circuit;
c) a voltage detecting circuit for detecting a voltage of said main capacitor;
d) a control circuit for controlling starting and stopping of said voltage boosting circuit; and
e) an oscillation frequency detecting circuit for detecting an oscillation frequency of said voltage boosting circuit, wherein said control circuit compares the oscillation frequency of said voltage boosting circuit detected by said oscillation frequency detecting circuit with a reference frequency corresponding to a voltage charged in said main capacitor.
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16. A flash apparatus comprising:
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a) a transformer composed of a primary winding and a secondary winding;
b) a switch element connected to the primary winding of said transformer for causing a current to flow from a battery to the primary winding;
c) a main capacitor to be charged by being connected to the secondary winding of said transformer;
d) an auxiliary power source to be created by said battery;
e) a circuit member to be driven by said auxiliary power source for controlling conduction and non-conduction of said switch element; and
f) a one-direction conduction element having an input terminal and an output terminal disposed in a charge loop of said transformer and said main capacitor, wherein an output end of said one-direction conduction element is connected to said auxiliary power source and said circuit member through a resistor, said switch element is made conductive through said circuit member in response to a voltage drop of the output end of said one-direction conduction element which is caused by a charged current flowing to a charge loop of a capacitor, and said switch element is made non-conductive through said circuit member by the charged current dropping and the output end of said one-direction conduction element being biased by said auxiliary power source.
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Specification