| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a light source lighting device capable of alleviating a stress to an electrical element used for a constant current power supply part by a so-called "soft start effect". <P>SOLUTION: An integration circuit (a resistor 25a and a capacitor 26a) continuously receives a target signal indicating a target value of a DC current to be flowed through LEDs 8a connected to a first step-down chopper circuit 30, and outputs an output value according to the target signal. An error amplifier composed of an operational amplifier 22a, a capacitor 23a, and a resistor 24a compares a detection value corresponding to the DC current flowing through the LEDs 8a with the output value of the integration circuit. A control IC 20a drives and controls the first step-down chopper circuit 30 on the basis of a comparison result by the error amplifier. Although a control circuit 13 continuously outputs the target signal to the integration circuit of a driving circuit 10a, an output start timing of the target signal to the integration circuit is after the supply of a control power supply generated by the control power supply circuit 11 to the driving part 10a is started. <P>COPYRIGHT: (C)2013,JPO&INPIT |
