| 摘要 |
PROBLEM TO BE SOLVED: To provide a laser-module temperature control circuit which can detect the temperature of a laser light-emitting element, without being influenced by changes in the temperature of the usage ambient, and by which the temperature control of the laser light-emitting element can be enhanced. SOLUTION: A reference voltageγVref, which is applied to respective positive input terminals of operational amplifiers 15, 16, is adjusted by a voltage adjustment means (not shown). Consequently, the output voltage of the operational amplifier 16 at a set temperature T1 of the control circuit 9 can be set at the intermediate value of the input voltage range of an A/D conversion circuit 8. When a variable resistor 23 is adjusted, the gain of the operational amplifier 16 is adjusted, and the output voltage of the operational amplifier 16 becomes allocated over the whole range of the input voltage range of the circuit 8. A reference voltage Vref in each part, the reference voltageγVref and a reference voltageβVref can be generated from the same power supply.
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