| 摘要 |
PURPOSE:To render image density uniform by forming an electrostatic latent image corresponding to a specified pattern of constant density on a photoreceptor at the same time as an electrostatic latent image corresponding to the image to be copied is formed. CONSTITUTION:Exposure-scanning photoreceptor 8 in accordance with the image to be copied forms on photoreceptor 8 an electrostatic latent image corresponding to the image to be copied, and this latent image is developed in developing unit 10 with a bias voltage applied in the title copying machine. In forming the latent image corresponding to the image to be copied, an electrostatic latent image corresponding to specified pattern 3 of constant density is simultaneously formed on photoreceptor 8, and the developed density of the electrostatic latent image corresponding to this specified pattern is detected with detector 22. The title machine is provided with a bias voltage control circuit for variably controlling development bias voltage in accordance with the results obtained by judging the developed density of pattern 3 on the basis of output signal of detector 22. |
