Patent ID: 9405211
Filing Date: 2016-08-02
CPC Classification: G02B,G03G,H01S

Claim Text:
1. A light source drive circuit for driving a light source, comprising: a drive current generating unit configured to generate a drive current, the drive current including a predetermined current for obtaining a predetermined light amount from the light source, a first auxiliary drive current input to the light source prior to input of the predetermined current, and a second auxiliary drive current added to the predetermined current in synchronization thereto; and a signal generating unit configured to generate a first signal and a second signal, the first signal causing the first auxiliary drive current to be input for a first period and the second signal causing the second auxiliary drive current to be applied to the predetermined current for a second period, wherein the first period is configured to be shorter than a period from a rise of the predetermined current to when a light amount from the light source reaches the predetermined light amount with the predetermined current; a light receiving element configured to receive light emitted from the light source and output a signal of a magnitude corresponding to an amount of the light received; an integrating unit configured to integrate a signal waveform output from the light receiving element; a current value setting unit configured to set a value of the second auxiliary drive current; and a lighting pattern storage unit configured to store therein a lighting pattern signal for lighting the light source for a predetermined period and turning off the light source for a predetermined period, wherein the current value setting unit includes wherein the current value is set to the second auxiliary drive current when the integrated value falls within the predetermined range.