| 摘要 |
<p>Provided is a semiconductor laser driver which can control generation of an excessive drive current when interruption of optical output is terminated. The semiconductor laser driver comprises drive current control sections (6, 8) for increasing the drive current of a semiconductor laser (2) when a differential voltage obtained by subtracting the value of an input current from the value of a reference voltage has a positive value, and decreasing the drive current of the semiconductor laser (2) when the differential voltage has a negative value; a resistance (7a) for converting a supplied current into a voltage and supplying the converted voltage to the drive current control sections as the input voltage; a photodiode (5) for receiving a part of light from the semiconductor laser (2) and supplying a current having a magnitude corresponding to the quantity of received light to the resistance (7a); and a circuit (9) for avoiding instantaneous light emission, in which a current path for supplying a current of a predetermined magnitude to the resistance (7a) is formed when the semiconductor laser (2) is in the state of interrupting optical output, and the current path is interrupted when interruption of optical output is terminated.</p> |
