| 摘要 |
<P>PROBLEM TO BE SOLVED: To prevent the occurrence of defects of image quality due to displacement of a developing vessel when using a coupling in a route for transmitting a driving force to the developing vessel in an image forming apparatus. <P>SOLUTION: A compression coil spring 52 is set so as to satisfy at least a relational expression (1) of F≥1.0(m×t/d)-m×G×cosθ, wherein m is a weight (kgf) of a developing vessel 32A of the developing unit 20; F is a pressing force (contact load)(kgf) energizing the developing vessel 32A toward a photoreceptor drum 16; d is a joint diameter (cm) of the coupling transmitting the driving force from an apparatus body to the developing vessel; t is a maximum value (kgfcm) of torque acting upon the coupling; θ is an angle (degrees) at which the arrangement position of the developing vessel 32A is inclined clockwise in a peripheral direction of the photoreceptor drum with an upward perpendicular direction as 0 degree when viewed from an axial direction of the photoreceptor drum 16; and G is a gravity acceleration. Thus, even in the case that axial deviation of the coupling is caused to vary the torque, the developing vessel 32A is not displaced, and an image of high quality can be obtained. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
