Developing unit

摘要

A developing unit includes a developing tank (41) and a toner hopper (42). The developing tank is disposed to oppose a recording medium (1) rotatably mounted to an image forming apparatus utilizing electrophotography, and has a developing member conveying a developer and attaches toner to an electrostatic latent image formed on the recording medium to develop the electrostatic latent image. The toner hopper has a toner supply port (45) for supplying the toner to the developing tank through a toner replenishing port (43) formed in the developing tank. The developing tank is detachable in a direction of a rotating shaft of the recording medium, and is movable in a direction perpendicular to the direction of the rotating shaft of the recording medium so as to separate from or oppose the recording medium. The toner hopper has a shutter (46) for opening/closing an opening of the toner supply port.