Light output control circuit

摘要

Using a switching signal from a coarse/fine switching and operation mode switching circuit (26), the width of change of a counter control value during power up is increased, and the width of change is reduced once a steady state is reached. In the steady state, the frequency of updating is limited by a control signal from an update permit control circuit. In the steady state, the frequency band of a current source in an LD driving circuit (10) is reduced in width.