| 摘要 |
PURPOSE:To attain intermediate tone information without unevenness and to perform exposure in a required minimum time, by making a power applied to a recording light source constant at each scanning line, keeping constant the temperature of a junction part of an LED and making constant a light emitting efficiency of the LED on each scanning line. CONSTITUTION:The sum between an electric energy for exposure P1 obtained from an exposure power P1(t) and a correcting electric energy P2 obtained from a correcting power P2(t) is a constant value PC at all times. Thus, there exists the relation of complement between the exposure power P1(t) and a correcting power PL. Further, the exposure power P1(t) is compared with a constant value PC(t)=PL at a comparator 21, resulting that PC(t)-P1(t) is outputted. Thus, a correcting power generator 32 generates the correcting power P2(t). Moreover, the exposure power P1(t) and the correcting power P2(t) are summed at an adder 33 and outputted. |
