| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a semiconductor laser drive circuit, etc. which can rapidly control with a single power source, in a drive circuit for a semiconductor laser element having a semiconductor laser diode commonly connected through cathodes to each other and a photodiode for monitoring. <P>SOLUTION: In the semiconductor laser drive circuit, when a laser diode 30 emits light, current flows to the photodiode 31 for monitoring, and a control signal in response to a voltage level V4 responding to the current and a reference voltage level Vref is applied from a differential amplifier 34 to an NPN transistor 32 to be operated on. Also, a reverse bias voltage is applied to the photodiode 31 for monitoring. Thus, a high speed APC control by the single power supply can be performed. <P>COPYRIGHT: (C)2005,JPO&NCIPI</p> |
