| 摘要 |
PURPOSE: To improve printing quality by executing a halftone cell selection standard and a pixel gray level selection standard, selecting the gray level of a cell and reducing the influence of noise. CONSTITUTION: Power sources 83, 84 and 85 drive a diode laser 25, expose a light receiving body and supply the power source output of different levels for forming electrostatic latent images corresponding to the image contents of the image signal output of an array 70. That is, the power source 83 outputs the first intensity level beam of light gray, the power source 84 outputs the second intensity level beam of dark gray and the power source 85 outputs a black third intensity level. A white forth level is by not sending control signals from a power source controller 81 to the power sources. At the time, the diode 25 does not expose the light receiving body and thus, images are not developed. A halftone cell memory 79 is selected for providing an average gray reflectivity for improving the copying of images. Thus, the influence of nonuniformity in a xerography printing process is minimized. |
