| 摘要 |
PURPOSE:To prevent the generation of the roughness of the horizontal line of an output image, the irregularity of the dot area occupying ratio of a dot applying image and the non-uniformity of the line width of a vertical line, by repeatedly performing the time sharing driving of optically modulable elements divided into groups at every group per one writing cycle. CONSTITUTION:After the serial data signals D1, D2 of one line are inputted, the data signal held to the output of a latch 24 by the application of a pulse signal L is subjected to time sharing by a duty gate 23 to be outputted to a photosensitive body and LED 21 is operated at every group but the time sharing output of signals E1, E2, E3, E4 at every one pulse is repeatedly performed 128 times per one writing cycle. Therefore, LED 21 of each group is not operated in a state biased to a definite time during one writing cycle but almost uniformly operated over an entire cycle and, since one operation time is extremely short, the shift quantity in a moving direction in the writing to a photosensitive body rotating at an equal speed is extremely small and a clear image can be obtained. |
