| 摘要 |
PROBLEM TO BE SOLVED: To provide a light-emitting element drive control circuit that suppresses subharmonic oscillation. SOLUTION: The light-emitting element drive control circuit includes: a control circuit connected in series with a light-emitting element and an inductor so as to turn on/off a transistor, controlling an increase/decrease in a drive current of the light-emitting element, on the basis of a control signal; a maximum value detection circuit for detecting the maximum value of the drive current; and a control signal generating circuit which generates a control signal that turns on the transistor so as to increase the drive current at a speed according to a level of a power supply voltage when the drive current is smaller than the maximum value or turns off the transistor so as to decrease the drive current for a prescribed period of time at a speed according to a level of a forward voltage of the light-emitting element when the drive current becomes the maximum value on the basis of the detection results of the maximum value detection circuit. COPYRIGHT: (C)2010,JPO&INPIT |
