| 摘要 |
<p>A light source protecting device (40) is provided to suppress excessive light emission of a laser diode. The light source protecting device (40) includes a temperature sensor (21) and a resistance variable device (30). In a laser diode (20) which is a light source for irradiating a disc with read light or the like, power is supplied from a power supply (Vcc). A temperature sensor (21) detects an ambient temperature, namely, a use temperature, of a laser diode (20). The resistance variable device (30) changes a limit value of a drive current supplied to a laser diode from the power supply (Vcc) based on the ambient temperature of the laser diode (20) measured by the temperature sensor (21).</p> |
