| 摘要 |
PURPOSE:To maintain a stable image with little environmental variation for all images over a long period of time by varying a replenishing quantity of developer based on a detecting signal of a first standard image, and compensating the developing electric field of an image part of an image carrier based on a detecting signal of a second standard image. CONSTITUTION:The first standard image and the second standard image area at least formed on the image carrier 1 by an electrophotographic process, the replenishing quantity of the developer is varied based on a detecting signal of the first standard image by an optical sensor 10, and at the same time, the developing electric field of the image part of the image carrier 1 is compensated based on the detecting signal of the second standard image. Furthermore, an image pattern which becomes a contact image after visualizing is used for the first standard image, and a dot or a line image is used for the second standard image. Thus, even when there is change in the surface potential of the image carrier by environmental variation or deterioration by aging, any of the contact, line, or not images can be obtained stably over a long period of time. |
