| 摘要 |
PROBLEM TO BE SOLVED: To provide an image forming unit capable of obtaining a satisfactory image in a stable state at any time while keeping the center distance between a photoreceptor and a developing roller constant, irrespective of an environmental change such as a change in temperature, to provide a process cartridge equipped with the image forming unit and an image forming device equipped with the process cartridge. SOLUTION: As for the image forming unit, provided that the center distance between the photoreceptor 12 and the developing roller 18 is expressed by L, the radius of the developing roller 18 is expressed by R, the radius of the core bar of the developing roller 18 is expressed by (r) and the coefficient of linear expansion of a positioning member 70 is expressed by α, and the coefficient of linear expansion of the developing roller 18 is expressed by β, the values L, R and (r) are set so as to satisfy α×L=β×(R-r), then, the center distance between the photoreceptor drum 12 and the developing roller 18 is kept constant, irrespective of the temperature. |
