| 摘要 |
PURPOSE:To heat and clean up sticking foul by providing a heater on the surface of heat-resisting glass on the detection surface of a optical sensor. CONSTITUTION:The light emitting element 1a and photodetecting element 1b of the reflective type optical sensor 1 are connected to power sources Vcc of +5 and +12V respective and a signal is outputted from the other terminal of the element 1b. The electrode of the ceramic heater 3 is grounded and also connected to a transistor (TR) Q1 with lines (l) through the heat-resisting glass 2 on the detection surface of the optical sensor 1, and the Q1 turns on the impress a +5V voltage to the heater 3. The on-off operation of the TRQ1 is so controlled on the basis of the detection output of the thermistor 6 of a fixing device 5 that the TRQ1 is turned on through a CPU4 for 60sec when the temperature of the device 5 is, for example, <=30 deg.C while a copying machine is powered on. Therefore, the +5V voltage is impressed to the heater 6 for 60sec to perform heating at about 500 deg.C and cleaning, thus removing foul. |
