| 摘要 |
PURPOSE:To maintain the service life of developer and to prevent deterioration of image due to soiling of a sleeve by providing a temp. sensor, and constituting an image forming device to rotate the sleeve one rotation or more prior to the developing. CONSTITUTION:The humidity detected by the sensor 31 provided in the vicinity of the developing unit 20 is compared with a threshold value. In normal environment, the humidity exceeds the threshold value, and the rotation of the sleeve 22 begins right before the electrostatic latent image on the photoreceptor 10 reaches the development position. On the other hand, in the environment in which the humidity detected by the sensor 31 is bellow the threshold value, the rotation of the sleeve 22 is started a little earlier so that the sleeve 22 is rotated one or more rotation before the electrostatic latent image on the photoreceptor 10 reaches the development position. Thus, in the normal environment in which there is no fear of occurrence of the sleeve soiling, the time of developing is kept short, therefore, the service life of the developer is secured. Moreover, in the environment of a low humidity, the developing is performed after the sleeve soiling is removed by rotating the sleeve 22, thus the deterioration of the image caused by the sleeve soiling can be avoided. |
