| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a semiconductor-laser driving device capable of suppressing the generation of an excess driving current at a time when optical-output interruption is released. <P>SOLUTION: The semiconductor-laser driving device has driving-current control sections (6 and 8) increasing driving currents for a semiconductor laser 2 when the value of a difference voltage obtained by subtracting the value of an input voltage from the value of a reference voltage is a positive value and reducing the driving current for the semiconductor laser 2 when the value of the difference voltage is a negative value. The semiconductor-laser driving device further has a resistor 7a converting a supplied current into a voltage and supplying the driving-current control section with the converted voltage as the input voltage, and a photo-diode 5 receiving a part of light from the semiconductor laser 2 and supplying the resistor 7a with the current having a magnitude corresponding to the quantity of the received light. The semiconductor-laser driving device further has an instantaneous emission-avoidance circuit 9 forming a current path for supplying the resistor 7a with the current having a predetermined magnitude in the state of the optical-output interruption of the semiconductor laser 2 and interrupting the current path when the optical-output interruption is released. <P>COPYRIGHT: (C)2009,JPO&INPIT</p> |
