| 摘要 |
PURPOSE:To restrain the temperature rise of a halogen lamp, to miniaturize a device and to reduce cost by changing the lighting time of the halogen lamp in accordance with the signal of a temperature detection part arranged near the halogen lamp. CONSTITUTION:The detection signal of the temperature of the halogen lamp 5 by a thermistor 14 is inputted in a main driving plate 22, and the lighting time of the lamp 5 is set by the plate 22 based on the detection signal. The lighting time is set in the lamp on-timing buffer of the driving plate 22 in accordance with the discrimination of the detected temperature. It is assumed that the lighting time is 250ms in the case of >=200 deg.C, 30ms in the case of 100-200 deg.C, and 350ms in the case of <=100 deg.C. The time required for the rise of the lamp 5 is changed according to the temperature and the lighting time is adjusted in accordance with the change. Thus, the calorific value of the lamp 5 is kept to the minimum and the capacity of a cooling fan 23 becomes small at the same time. |
