| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain an image forming device which prevents deterioration in a black toner and which produces no thinning in a print by controlling the volume average particle size of a black toner to be larger than the volume average particle size of other color toners. SOLUTION: A yellow toner is housed in a yellow developing part 6a, and its volume average particle size is 7μm. Magenta and cyan toners are housed in the magenta and cyan developing parts 6b, 6c, respectively, and the volume average particle size of the toners is also 7μm. However, the black toner housed in the black developing part 6d has 10μm volume average particle size. Thereby, by controlling the volume average particle size of the black toner to be larger than the other toners, the black toner has durability, which prevents deterioration in the fluidity. Thereby, even when printing with low printing duty or monochromatic printing in which a large amt. of the black toner is used is carried out so much, thinning in the print is not caused.</p> |
