| 摘要 |
PROBLEM TO BE SOLVED: To provide a driving circuit of a lamp for a projector capable of suppressing the screen flicker of the projector occurring due to an alternating current power source. SOLUTION: Because a variation in power supplied to a lamp 14a caused by a variation in predetermined direct-current voltage caused by a commercial AC power 21 is suppressed by PWM controlling by a power supply circuit 19b by a PWM control circuit 19g based on a voltage dividing signal from a circuit 19f for forming a voltage dividing signal including a variation component of the predetermined direct-current voltage caused by the commercial AC power 21, the screen flicker of the projector 10 occurring due to the commercial AC power 21 can be suppressed. Because the screen flicker caused by the commercial AC power 21 can be also suppressed even if the capacity of a capacitor for smoothing a rectifier circuit 19a is small, the capacitor for smoothness can be made to be small. Therefore, increases in the cost and size of the driving circuit 19 can be suppressed to be advantageous to reduction in the size and cost of the projector 10. COPYRIGHT: (C)2009,JPO&INPIT |
