Image forming apparatus with a power-transmission assembly

摘要

An image forming apparatus (1) having an improved power-transmission assembly to drive a developing cartridge (40) mounted in a main body (10) of the apparatus. The apparatus (1) includes a main body (10), at least one driving coupling unit (110) rotatably located in a side region of the main body, at least one driven coupling unit (45) connected to a rotator (41, 43) inside a developing cartridge, and a coupling holder (120) in which the driving and driven coupling units are connected to each other to enable a power-transmission from the driving coupling unit (110) to the driven coupling unit (45). The driving coupling unit (110) includes a first spherical portion (112) to come into contact with one side of an inner surface of the coupling holder (120) when received in the coupling holder. The driven coupling unit (45) includes a second spherical portion (45a) to come into contact with the other side of the inner surface of the coupling holder (120) when received in the coupling holder.