| 摘要 |
PURPOSE:To vary the recording density of pictures, by switching the size of a laser beam spot and at the same time controlling the lighting interval, lighting control cycle, moving speed of the surface of a recording medium, etc. CONSTITUTION:A spot size controlling optical system 6 is controlled by a recording density setter 15. Thus the size of a radar spot 2c is switched. At the same time, a laser beam producing circuit 13, dividers 17 and 18 which divide the clock period, etc. in response to the operation of the setter 15. Thus the control is given to the spot lighting time interval per picture element of a picture information signal, the speed of revolution of a photosensitive drum 7 produced via a motor controlling circuit 14, the lighting control period of a spot 2c produced by a scan synchronizing circuit 12, etc. The pictures of different dot sizes and high quality are formed with the above-mentioned interlocking control. Thus it is possible to change the recording density of pictures. |
