| 摘要 |
PURPOSE:To maintain the picture quality of a halftone image excellently by detecting the potential of a photosensitive body which is exposed to light modulated with a modulating signal corresponding to halftones and controlling the intensity of image light to which the photosensitive body is exposed in correspondence to the detected potential. CONSTITUTION:A CPU20 sets the output current level of a driving circuit 13 to Is as a reference current value and a laser 9 is modulated and driven with a driving current F with the current value corresponding to signal C, thereby flashing. A projected laser beam 3 having intensity corresponding to the current value Is is scanned on the photosensitive body 1 for exposure. The surface potential of the exposed photosensitive body 1, i.e. potential Vs of a sample halftone latent image is detected by a potential sensor 21. Then, the CPU20 selects the current level of the driving current F, i.e. intensity of image light for the formation of the halftone image with desired density. |
