| 摘要 |
<P>PROBLEM TO BE SOLVED: To accurately inform of a replacement time of a photoreceptor by accurately measuring a photosensitive thin film of the photoreceptor. <P>SOLUTION: An overshoot portion P of a measurement current Iref which occurs when a current of a DC component to a photoreceptor drum through a charging roller is removed by processing in a control part 30, whereby an amount of charge accumulation Q3 not including the overshoot portion is calculated and an amount of film reduction corresponding to the calculated amount of charge accumulation Q3 approximates to an actual amount of reduction of a photosensitive thin film. As a result, erroneous determination that the photoreceptor drum is determined to be replaced though not reaching the usage limit is prevented. <P>COPYRIGHT: (C)2007,JPO&INPIT |
