PRINTING DENSITY CONTROL SYSTEM FOR LASER PRINTER

摘要

PURPOSE: To provide printing with a stable printing density even the when the number of printing colors is changed, on the printing density control system for a laser printer capable of multicolor printing. ;CONSTITUTION: Basically, a constitution is adopted so that the quantity of toner attracted to the photosensitive surface 1a of the photosensitive drum 1 on each of plural developing units 2, is increased according to the number of the developing units 2 of the rear steps of the developing units 2. The increase of the quantity of the toner attracted to the photosensitive surface 1a, such that, is executed by making the laser power of a laser beam 4 high by a laser power control means 5 controlling a voltage applied to a laser light source 3, and a constitution that the quantity of the toner attracted to the photosensitive surface 1a is increased, by making a developing bias high by a developing bias control means 6 controlling the developing bias applied to the developing unit 2, can be adopted. Therefore, even when the toner attracted to the photosensitive surface by the developing unit of the front step, is scratched off by the developing unit of the rear step, a constant toner quantity is obtained at the time of completing development, so that the printing is executed with the stable printing density.;COPYRIGHT: (C)1993,JPO&Japio