| 摘要 |
PURPOSE: To provide a toner misregistration detecting sensor capable of detecting both of toner concentration and toner misregistration, a color image forming apparatus provided with the same and a toner misregistration detecting method. CONSTITUTION: Infrared light emitted from an infrared light emitting diode 2 is reflected by the toner being a material to be detected and the reflected light is received by a photodiode 3. A signal detecting circuit is constituted so as to connect an amplifier 5 for converting the output current of the photodiode 3 into voltage, an amplifier 6 having an optimized circuit constant to detect the color toner concentration, an amplifier 7 having an optimized circuit constant to detect the black toner concentration and an amplifier 8 having an optimized circuit constant to detect the toner misregistration into 2 stages. The output voltage of the 1st stage amplifier 5 is further amplified by the 2nd stage amplifiers 6, 7 and 8 and outputted as a color toner detection output Vo1, a black toner detection output Vo2 and a toner misregistration detection output Vo3. |
