| 摘要 |
PROBLEM TO BE SOLVED: To provide a semiconductor laser driving device which supplies an optimum threshold current and drives with an ideal light-emission delay and an ideal light-emission pulse width even for a semiconductor laser element in which linearity of a light emission quantity to a driving current is lost.SOLUTION: In a semiconductor laser driving device, a current setting circuit 10 stores a first setting value corresponding to a light-emission current Isw obtained by subtracting a bias current Ithon when an LD emits light from a driving current Iop when the LD is caused to emit light at a desired light-emission quantity Po, a second setting value corresponding to the bias current Ithon, and a third setting value corresponding to a bias current Ithoff when the LD does not emit light. A current generation circuit 1 generates a first input current from the first setting value, and a current generation circuit 2 generates a second or third input current from the second or third setting value. A switch TR3 and a multiplexer 3 send a sum of the first and second input currents to a driving circuit when a light-emission control signal is ON, and send the third input current to the driving circuit when the light-emission control signal is OFF. |
