| 摘要 |
PURPOSE:To obtain invariably stable contrast by detecting and storing the potential on a photosensitive body between two electrostatic latent images formed continuously on the photosensitive body, and determing the image formation codition of the 2nd image from the potential right before the 2nd image is formed. CONSTITUTION:A photosensitive drum 1 is rotated as shown by an arrow and discharged 12 electrostatically by a light source 11 for primary corona discharge 13, and secondary electrostatic discharging is carried out by a secondary corona discharger 15. The light source 25 projects reflected light scanning on an orignal on an original platen 26, and entire-surface exposure 16 is perfomed to complete the latent image formation. Then, a potential detection sensor 21 detects the surface potential of the photosensitive drum 1, and the image is developed 17, transferred 18 to a form 20, and fixed by an unshown fixing part. the output of the sensor 21 is amplified 22 and supplied to and stored in a control means 23. The control means 23 controls a power source 24 with a timing signal 29 for the formation of each image and a signal from a copy counter 28 to control the voltage of an original lamp 25, holding the potential on the photosensitive drum 1 constant. Consequently, images with invariably stable constant are formed. |
