| 摘要 |
PURPOSE:To enable stable operation in a wide temperature range even for an LED having large temperature characteristics, by mounting an LED device, a Peltier device and a temperature sensor on a heat radiating mechanism and by controlling LED dividing current and Peltier device driving current at the same time based on internal temperature information through the temperature sensor. CONSTITUTION:A transmission pulse 16 is input to an LED driving circuit 4, and an LED driving signal 13 of which amplitude is controlled by an LED driving current control signal 12 from a driving current control circuit 5 is output. The signal 13 is converted to optical output signal 10 by an LED device 1 and the signal 10 is output. A temperature sensor 3 is mounted on a heat radiation mechanism which is integrally provided on the device 1. A temperature sensor temperature 21 is sent to the circuit 5 as detected temperature information 11. The control signal 12 and Peltier device driving current control signal 14 are generated at the same time in the circuit 5 based on the information 11 from the sensor 3. The relationship between the control signal 12 and the signal 14 is set at a desired value to cancel the temperature dependency of the output signal 10. |
