POWER SUPPLY DEVICE AND LIGHTING EQUIPMENT
First Claim
1. A power supply device comprising:
- a semiconductor light-emitting element;
a current control circuit which controls a current supplied to the semiconductor light-emitting element;
a voltage control circuit which controls a voltage applied to the semiconductor light-emitting element; and
a dimming controller which receives a dimming signal having a certain dimming depth, sets a current control mode and/or a voltage control mode according to the dimming depth, controls the current control circuit to drive the semiconductor light-emitting element at a target current specified depending on the dimming depth when the current control mode is set, and controls the voltage control circuit to drive the semiconductor light-emitting element at a target voltage specified depending on the dimming depth when the voltage control mode is set.
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Accused Products
Abstract
In a power supply device according to one embodiment, a reference signal Vref1, which changes from a value corresponding to a maximum current in a full lighting state to that corresponding to a minimum current in case of a deepest dimming depth, and a reference signal Vref2, which changes from a value corresponding to a load voltage at the time of a maximum current in a full lighting state to that corresponding to a minimum current in case of the deepest dimming depth, are prepared in accordance with dimming depths of a dimming signal. In a shallow dimming depth region close to a full lighting state, the reference signal Vref1 is selected to apply constant-current control to light-emitting diodes in a current control mode. In a deep dimming depth region, the reference signal Vref2 is selected to apply constant-voltage control to the diodes in a voltage control mode.
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Citations
7 Claims
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1. A power supply device comprising:
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a semiconductor light-emitting element; a current control circuit which controls a current supplied to the semiconductor light-emitting element; a voltage control circuit which controls a voltage applied to the semiconductor light-emitting element; and a dimming controller which receives a dimming signal having a certain dimming depth, sets a current control mode and/or a voltage control mode according to the dimming depth, controls the current control circuit to drive the semiconductor light-emitting element at a target current specified depending on the dimming depth when the current control mode is set, and controls the voltage control circuit to drive the semiconductor light-emitting element at a target voltage specified depending on the dimming depth when the voltage control mode is set. - View Dependent Claims (2, 3, 6)
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4. A power supply device comprising:
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a semiconductor light-emitting element; a voltage detection circuit which detects a voltage applied to the semiconductor light-emitting element, and outputs a first detection signal; a current detection circuit which detects a current supplied to the semiconductor light-emitting element, and outputs a second detection signal; and a dimming controller which receives a dimming signal which is set at one of a deepest first dimming depth, a shallowest second dimming depth, and a certain third dimming depth between the first dimming depth and the second dimming depth, drive-controls the semiconductor light-emitting element according to the first detection signal so that the voltage becomes a first target value when the first dimming depth is set, drive-controls the semiconductor light-emitting element according to the second detection signal so that the current becomes a second target value when the second dimming depth is set, and drive-controls the semiconductor light-emitting element according to the first detection signal and the second detection signal so that the voltage and the current respectively become a third target value and a fourth target value when the third dimming depth is set, wherein the dimming controller drive-controls the semiconductor light-emitting element depending on the first detection signal compared to the second detection signal as the third dimming depth is closer to the first dimming depth, and drive-controls the semiconductor light-emitting element depending on the second detection signal compared to the first detection signal as the third dimming depth is closer to the second dimming depth. - View Dependent Claims (5, 7)
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Specification