| 摘要 |
PURPOSE:To prevent a response speed, where a pulse radiation is made to occur or terminate, substantially from delaying by a method wherein a capacitance element is connected between a collector of a third transistor and a base of a fourth transistor. CONSTITUTION:A voltage drop at both ends of a laser diode D fluctuates transitionally rising up and falling down at the rise and fall transition time of a pulse signal that transistors Q1 and Q2 are in an ON or OFF state respectively, whereby a collector voltage of a transistor Q3 fluctuates transistionally rising up and falling down and the fluctuation component of the voltage is given to the base of the transistor Q3, so that the base voltage fluctuates falling down and rising up. At this time, the fluctuation component of the collector voltage of the transistor Q3 is given to the base of the transistor Q3 through a capacity element CS, wherefore the base voltage of a transistor Q4 also fluctuates transitionally falling down and rising up. |
