| 摘要 |
PURPOSE:To obtain an inexpensive electrophotographic printer for which a RAM for temporary storage is not used by writing directly a latent image in the surface of a photosensitive drum by an LED head from an image signal from a host computer. CONSTITUTION:An image processing unit 16 brings an image signal from a host computer 11 to conversion processing to a video signal and sends it to an LED driver 14, and outputs scanning line position information corresponding to this video signal to a motor control circuit 18. A control circuit 18 rotates a step motor 17 in the B direction and divides and stops a photosensitive drum 21 in a position in which an LED head 20 faces the scanning line position concerned from a reference point 21a, and by a position dividing completion signal of the motor 17, the LED driver 14 allows an LED array 2 to emit a light beam and exposes the surface of the drum 21. By an exposure completion signal, the processing unit 16 outputs a transmission request of an image signal corresponding to the next scanning line to the computer 11, and in the same way, the exposure is executed one after another in accordance with the scanning line and a latent image is drawn on the surface of the drum 21. In such a way, a RAM for temporary storage becomes unnecessary. |
