| 摘要 |
PURPOSE:To restrain the power from being wastefully consumed because of the temperature control and the production cost from rising by performing the temperature control of a heater based on the light quantity of a fluorescent lamp after starting forming an image. CONSTITUTION:A light quantity sensor 1-3 for detecting the light quantity of the fluorescent lamp 1-2 is constituted by combining a photodiode and an amplifier. A driving circuit 1-6 controls the power for the heater 1-1 with a TRIAC element incorporating a zero cross detection circuit of an AC power source inputted. When forming the image is started and lighting the fluorescent lamp 1-2 is started, a controller 1-5 counts the time from starting the lighting with a built-in timer, and reads the light quantity of the fluorescent lamp 1-2 at the time of attaining the specified time, from the sensor 1-3. When the read value is equal to or under a specified value, the driving circuit 1-6 is actuated to start the energizing of the heater 1-1 so as to raise the temperature of the tube wall of the fluorescent lamp 1-2 and increase the light quantity. |
