| 摘要 |
PURPOSE:To record a picture with excellent resolution by providing a memory storing the density level of picture elements adjacent to picture element region while being irradiated at present, a means for changing the time width of an irradiation pulse of a light beam proportional to the density level and a means for changing the start time of an irradiation pulse of a light beam. CONSTITUTION:A picture signal read by an image sensor enters a shift memory 6 while the density level of each picture element is digitized. A semiconductor laser 1 is modulated by a pulse width proportional to the density level of the shift memory 6 to be irradiated and irradiated on a photosensitive body 4. On the other hand, the density level of the picture element adjacent to the picture element being irradiated at present in the shift memory 6 is discriminated by a comparison circuit 7, and the start time of a drive pulse to the said semiconductor laser 1 is controlled by a control circuit 9 so that a laser beam spot is in contact with the picture element having a larger density level and the semiconductor laser 1 is driven by a signal from a pulse width modulation circuit 8. The laser light of the semiconductor laser 1 subjected to pulse width modulation scans on the photosensitive body 4 by a polygon deflector 2.
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