| 摘要 |
PURPOSE:To eliminate ground stains and to prevent decrease in the density of image quality by using toners for multiple colors which are spherically shaped and of which the size and variance of the grain size distribution are adjusted to prescribed values. CONSTITUTION:Units 10, 20, 30, 40 for forming electrification distributions having multistylus electrodes 14, 24, 34, 44, donors 11, 21, 31, 41 and means for supplying toners to the donors are provided. The colors T1, T2, T3, T4 of the toners to be used for each of the units are varied. The electrodes 14, 24, 34, 44 of the units 10, 20, 30, 40 are brought into contact with the toners of high electric resistance having charge holding property. The electrification distributions of the toners to be impressed to the electrodes 14, 24, 34, 44 of the units 10, 20, 30, 40 are obtd. on the donors 11, 21, 31, 41 by utilizing the charge implantation to the toners, by which the image patterns of the respective colors are transferred on the same recording sheet. The toners which are spherically shaped and of which the center of the grain size distribution is 5-15mu and the variance thereof is within + or -25% are used for the toners T1-T4 of the multiple colors by the above-mentioned method. |
