| 摘要 |
<p>PURPOSE:To realize a high-quality black and white printing or a high- reproducibility halftone printing with high resolving power by a method wherein a predetermined relation is held among a resolving power in image printing, the repeat number of light emitting actions of end emitting-type EL elements, and an average particle diameter of a developer supplied from a developing device. CONSTITUTION:In an end emitting-type EL printer, the repeat number S of light emitting actions of end emitting-type EL elements 2 for forming one pixel, a resolving power K (dots/mm), and an average particle diameter D (mm) of a toner meet a relation shown by a formula. By varying the element emitting number of each end emitting-type EL element 2 for one pixel, a gradation expression per pixel is performed. At this time, with the repeat number of S=4 and a resolving power of K=25(dots/mm), a toner having an average particle diameter of the order of D=1.2X10<-2>(mm) is used to meet the require ment of the formula. For example, when a pixel is printed with an intermediate density obtained by emitting and unemitting the element twice for each, only the irradiated area in one pixel area is developed, and a resulting halftone expression has an enhanced reproducibility.</p> |
