| 摘要 |
PURPOSE:To carry out detection and informing of unevenness in sensitivity or electrification quantity in the direction of a rotational shaft of a photosensitive drum with a simple mechanical constitution without using a potential sensor or an optical sensor. CONSTITUTION:A multiple number of reference latent image patterns 303 are formed in different positions in the direction of the rotating shaft and in the direction of the rotation on the photosensitive body 102, and developing current for developing the reference latent image patterns 303 is detected at a current detection circuit 301 connected to a developing sleeve 201 for each pattern. Then, the degree of unevenness in the sensitivity and the electrification quantity, etc., in the direction of the rotating shaft of the photosensitive drum 102 is judged by comparing developing current of each reference latent image pattern 303. When allowable range is exceeded, a display device 142 is driven and the exchange, etc., of the photosensitive body is prompted. When it is within the allowable range, the quantity of the laser beam at the time of image exposure is compensated so that the identical developing current can be obtained concerning the identical image data. |
