| 摘要 |
PURPOSE:To simplify a structure, by providing a reference toner image producing light source which uniformly illuminates a small part of the surface of a photosensitive body separately from the light source which forms the latent image of a recording picture on the surface of a photosensitive body. CONSTITUTION:At appropriate timing other than the picture recording timing by means of picture signals, an electrostatic latent image for picture density detection is produced on the photosensitive body 1 by means of a reference toner image producing light source 5. In the case of inversional development, only the exposed part of the photosensitive body 1 is developed and a toner image is formed. Therefore, the reference toner image producing light source 5 is used for the exposing part of the photosensitive body 1 necessary only for producing a reference toner image for density detection and, since the reference toner image is extremely small, a small light source can sufficiently be used as the light source 5. Accordingly, any complicated circuit configuration, such as a light quantity control circuit, circuit for producing picture signal to be used for generating prescribed pattern signals, etc., becomes unnecessary. |
