| 摘要 |
PURPOSE:To execute good picture control, by using a sensitivity compensating filter for a CCD, and making its overall sensitivity characteristic equal to an overall characteristic of a photoconductive layer, in a picture forming device which uses the CCD as a developing bias setting sensor. CONSTITUTION:Reflected light from a picture of an original P which transmits a half mirror 19 transmits a filter 4, converges to a CCD 3, and the photodetected CCD 3 sends out successively a photoelectric converting signal by a driving means 21. This signal passes through an amplifier 22, is converted to a digital signal by an A/D converter 23, and is inverted by a picture forming means 24. This inverted signal becomes the relation proportional to the charged potential on a photoconductive layer of a photosensitive drum 7 on which an electrostatic latent image of an original in the same part is formed. The inverted signal becomes the relation inversely proportional to a photodetector, therefore, the potential of this inverted signal becomes low in porportion to the charged potential of the photoconductive layer of the photosensitive drum 7. As a result, good picture control can be executed. |
