Patent ID: 7247996
Filing Date: 2007-07-24
Classification: H02M,H05B,Y02B

Abstract:
1. A projector comprising: a lamp for projection; a lamp driving circuit for driving the lamp; and a power supply circuit for supplying a predetermined DC voltage to the lamp driving circuit, the power supply circuit including a rectifier circuit for performing full-wave rectification on an AC voltage of a power source, a power-factor improving circuit for improving a power factor seen from the power source side, to which the voltage subjected to the full-wave rectification in the rectifier circuit is supplied, and a switching regulator to which the power-factor improving circuit is connected on a primary side of a transformer and from which a DC voltage for a load is output on a secondary side, and the lamp being turned on by supplying a lamp turn-on permission signal to the lamp driving circuit, wherein a signal detecting circuit for detecting the lamp turn-on permission signal is provided, and in a standby state in which the lamp turn-on permission signal is not detected by the signal detecting circuit, operation of a PFC (Power Factor Correction) control unit provided in the power-factor improving circuit is stopped based on an output of the signal detecting circuit.