SEMICONDUCTOR LASER MODULE AND ITS DRIVING METHOD

PROBLEM TO BE SOLVED: To restrain overcurrent energization to a thermo-module. SOLUTION: A thermo-module 5 carries out heating operation when a current from a lead pin 16f toward a lead pin 16a is energized. On the contrary, it carries out cooling operation when current from the lead pin 16a toward the lead pin 16f is energized. An overcurrent limitation means 20 for restraining overcurrent energization in a heating direction to the thermo-module 5 is provided. The overcurrent limitation circuit 20 has a bypass path 21, a resistor 22 and a diode 23. When current in a heating direction is energized, the diode 23 turns 'on' and current is shunted and flows to the thermo module 5 and the bypass path 21. Thereby, overcurrent energization to the thermo-module 5 can be restrained.