Emission control apparatus and image forming apparatus

摘要

There is provided an emission control apparatus with which it is capable of variably controlling the intensity of a light beam to be set, in a stable manner and at a low cost without increasing the circuit size. A semiconductor laser diode LD emits a light beam. A photo diode PD detects the intensity of the light beam emitted from the semiconductor laser diode LD. A driving circuit supplies driving current to the semiconductor laser diode LD. A switching section switches the driving current according to a video signal. An input terminal receives a pulse width modulation signal. A smoothing. circuit smoothes the received pulse width modulation signal. A laser driver controls a value of the driving current according to smoothed voltage obtained by the smoothing circuit such that the detected intensity of the light beam is equal to a target intensity.