DEVELOPING DEVICE, PROCESS CARTRIDGE, DEVELOPING UNIT CARTRIDGE AND IMAGE FORMING DEVICE

摘要

PROBLEM TO BE SOLVED: To make surely preventable toner leakage from a gap formed between a lower film and a side seal by providing both ends in the longitudinal direction of a lower end developer leakage preventing member on an attaching surface boundary part developer leakage preventing member so that the attaching surface boundary part developer leakage preventing member may be exposed. SOLUTION: Both ends in the longitudinal direction of the lower end developer leakage preventing member are provided on the attaching surface boundary part developer leakage preventing member so that the attaching surface boundary part developer leakage preventing member may be exposed. In this developing device, a lower side seal 105 functioning as the attaching surface boundary part developer leakage preventing member is attached to the end of a lower side seal attaching area 101 by using a double coated adhesive tape. The seal 105 is formed of a polyurethane sponge, and is pressed and brought into contact with the side seal 104 so that the side end face of the seal 105 and the side end face on the seal 104 side may be superposed at a partial area W0.