| 摘要 |
PURPOSE:To accurately maintain the main scanning timing of a write system without being mixed with a transient or noise by outputting a trigger signal to a clock generation means when there is an input from a detection means from after the output of picture data for one line to before the detection of the detection means. CONSTITUTION:The titled device is provided with the laser beam detection means D which is disposed on a position which can detect the passage of a laser beam, a clock generation means G3 which generates a clock by the input of the trigger signal and a decision means PROM which does not output the trigger signal to the clock generation means G3 even if there is the input from the detection means D from after the detection of the detection means D to before the output of picture data for one line and which outputs the trigger signal to the clock generation means G3 when there is the input from the detection means D from after the output of picture data for one line to before the detection of the detection means D. Consequently, the erroneous generation of a synchroniation detection signal due to the mixture of the transient such as an LD or a photodiode light receiving circuit, noise and stray light can be prevented. Thus, the reliability of the main scanning write timing is improved, and the abnormal picture of a printer, a copying machine or the like can be prevented.
|
