| 摘要 |
PROBLEM TO BE SOLVED: To detect the abnormal position of a density measuring device and to eliminate failure caused by the abnormal position by providing a position detecting means detecting the position of the density measuring device in an image forming device equipped with the movable type density measuring device measuring the density of an image formed on an image carrier at a regular measuring position. SOLUTION: A sensor position detecting part 66 is disposed at the next stage of an A/D fetching part 61 and a D/A setting part 65. The detecting part 66 compares output from the A/D fetching part 61 with a signal from the D/A setting part 65, judges output from a density sensor part 50, and discriminates a light emission state and a reflection state so as to detect the position of the sensor part 50. Namely, a light emitting source 51 is driven by emitted light quantity previously fixed through the D/A setting part 65 according to light emitting source driving data prepared in a CPU 60. Reflected light at such a time is detected by a reflected light detecting part 52 and the position of the sensor part 50 is judged according to the signal from the A/D fetching part 61. |
