| 摘要 |
PURPOSE:To establish high quality printing with an electrophotographic device using laser without requiring any action from the operator by controlling the printing density, etc., sheet by sheet. CONSTITUTION:A printing density auto-control system comprises a reflected light output sensor 1a to cast a visible ray of light to a sheet 10, a reflected light input sensor 1b to receive the reflected light from the sheet 10, and a laser drive circuit 3 to vary the drive current for semiconductor laser 4 of exposure process with the output of the input sensor 1b, and thereby the printing density depending upon difference in the sheet reflectance due to their colors is corrected. |
