| 摘要 |
PURPOSE:To enable the continuation of printing without exchanging a photosensitive drum even if the surface of the photosensitive drum is flawed or damaged by providing a means for setting timing which generates a reference position signal for the rotating position of the drum so that the recording part forms a latent image in synchronization with the reference position signal. CONSTITUTION:A slit plate 212 has two kinds of slit patterns concentrically. The dense slit pattern corresponds to the scanning intervals of a beam and the coarse slit pattern corresponds to the reference position signal for the rotating direction of a photosensitive drum 11. A control part 22 for recording has a preset counter 221. The counter 221 is started by the reference position signal (b) corresponding to the coarse slit pattern from an amplifier 214 to start counting down by the clock signal having a prescribed frequency. The counter 221 is so designed that when the count value thereof attains, for example, zero, the output thereof goes to a ''1''. The value from a digital switch SW is preset by the signal (b). When the output of the counter 221 goes to a ''1'', the scanning signal (a) corresponding to the dense slit pattern of the plate 212 is applied to a driving part 23 for recording, by which the recording is started. |
