| 摘要 |
PURPOSE:To provide a method for detecting the rotational speed of a photoreceptor for an electrophotographic system at a low cost with accuracy. CONSTITUTION:A prescribed latent image for detecting the rotational speed (A-1) is formed by using a latent image forming means which is naturally prepared for such an equipment provided with a photoreceptor used for the electrophotographic copying system (1st formation). After a time which is an integral multiple of one normal rotation time required for one rotation of the photoreceptor in the case that the photoreceptor is rotated at a normal speed, a prescribed latent image is formed again while leaving the former latent image as it is (2nd formation), then, a synthesized latent image is formed. When the photoreceptor is not rotated at the normal speed (B and C), the latent image formed at the 2nd time is shifted from the latent image formed at the 1st time, then, the synthesized latent image is elongated. Whether or not the rotational speed is a normal one is detected by comparing the length of the synthesized latent image with that of the normal latent image obtained when the photoreceptor is rotated at the normal speed. The deviation of the latent image reflects the difference of a rotating amount during a long period which is the integral multiple of one normal rotation time, then, the value is increased, and the detection accuracy is enhanced. And also, the cost is reduced by using the naturally prepared latent image forming means. |
