| 摘要 |
PURPOSE:To always obtain a recorded picture having superior resolution, brightness, half tone, smoothness, or the like by switching an electric field in accordance with the kind of the picture to be recorded. CONSTITUTION:A picture reader 12 reads out an original, outputs picture data I to a signal processor 1 and also outputs a discrimination signal D indicating whether the picture data I discriminated by the reader 12 is a linear picture or a tone picture to a control device 13. The control device 13 outputs a control signal C to a bias power supply 11. A processor 1 converts the picture data I to a binary image and outputs the binary image to a laser writing device 2. The device 2 exposes an image on the surface of a photosensitive drum 3 as a laser spot in accordance with the picture data. The formed electrostatic latent image is developed under an electric field increasing at least one of the amplitude and period of an AC component by a developing device 5 in case of a linear picture, and also developed under an electric field reducing at least one of the amplitude and period of the AC component in case of a tone picture, so that a linear picture having high resolution and brightness and a tone picture having superior reproducing property of a half tone are obtained. |
