| 摘要 |
<P>PROBLEM TO BE SOLVED: To properly protect a laser diode 1 from a high temperature environment. <P>SOLUTION: Based on two factors of a supply current value to the laser diode 1 flowing through a transistor 2 etc. and the ambient temperature of the laser diode 1 detected by a temperature sensor 12, a current is supplied to the laser diode 1 when the supply current value to the laser diode 1 is not higher than an upper limit current value and the ambient temperature of the laser diode 1 is not higher than a return temperature T1, but a main control circuit 11 controls a constant light output control circuit 9 to turn off a transistor 2 so as to disconnect the supply current to the laser diode 1 when the supply current value to the laser diode 1 exceeds the upper limit current value or when the ambient temperature of the laser diode 1 exceeds a guaranty upper limit temperature T2. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
