| 摘要 |
PROBLEM TO BE SOLVED: To prevent banding on an image from standing out by reducing the gear pitch of a photoreceptor drum, and to prevent the occurrence of interference fringes (gradation of image density) due to the reduction of the gear pitch and the approach to a pitch based on the number of basic lines for forming a half tone. SOLUTION: Provided that d(mm) denotes the diameter of the photoreceptor drum 2, a(mm) denotes a gear pitch, that is, the moving distance of the photoreceptor drum 2 surface in accordance with the rotation of a tooth of the drum gears integrally rotated with the photoreceptor drum 2, (c) denotes the number of teeth of the drum gears, (1) denotes the number of basic lines for forming the half tone, ad b(mm) denotes a pitch based on the number of basic lines for forming the half tone, by establishing the following inequalities between the gear pitch (a) of the photoreceptor drum 2 and the pitch (b) based on the number of basic lines, b/a= 25.4/1}/ (d×π)/c}>1.277, and also, a <=1.51, or b/a= (25.4/1)}/ (d×π)/c}<0.752, also, a <=1.51, the occurrence of the banding and the interference fringes are prevented. |
