| 摘要 |
<P>PROBLEM TO BE SOLVED: To perform light-emitting drive which is superior in rapid response by considering starting characteristics of a current flowing through a semiconductor light-emitting element as sufficiently steep characteristics. <P>SOLUTION: A semiconductor light source device includes: an LED 16; drive circuits (12 to 15) which intermittently drive the LED 16 with a constant current in accordance with a PWM signal and has the time constant; an FET 17 which interrupts the current flowing through the LED 16; and a current detection gate circuit 21 which detects a value of the current supplied to the LED 16 by the drive circuits (12 to 15) and energizes the LED 16 by turning the FET 17 on in a state where the value of the current supplied to the LED 16 becomes a predetermined level. <P>COPYRIGHT: (C)2012,JPO&INPIT |
