Color image forming device

Abstract

Abstract PURPOSE:To obtain a high-definition image as for a black image part according to the type of the image by providing two different black developing means for forming a full color image and monochrome image as for the black developing means in a developing means. CONSTITUTION:The black developing unit 17 is used as a pair with respect to a yellow developing unit 14, a magenta developing unit 15, a cyan developing unit 16, etc., at the time of a full color mode, etc. The black toner B of the developing unit 17 has the same type characteristic as the yellow toner E of the developing unit 14, the magenta toner D of the developing unit 15, and the cyan toner C of the developing unit 16, and the gamma characteristic as for respec tive toners B, C, D, and E is almost one. The developing unit 18 is used at the time of a monochrome copy mode, black toner A housed in the developing unit 18 has a characteristic different from a group of the above-mentioned respective toners B, C, D and E and the toner having the characteristic of gamma>1 suitable for a monochrome copy is used. Thus, the high-definition image is obtained according to the type of images of full color and monochrome records.

Inventors

• 👤 Nobuo Kasahara
• 👤 伸夫 笠原

Bibliographic Details