Electrophotographic development device.

摘要

An electrostatic latent image on a photosensitive drain (10) is developed by application of magnetic toner particles from an improved development device comprising a tank (14) for toner particles in which is arranged a rotary sleeve (11) containing a magnet roll (12). Rotation of the sleeve (11) and the magnet roll (12) sweeps chains of toner particles over the latent image on the drum (10) to develop it. The image after development can be degraded by the rotary magnetic field from the magnet roll (12) and to prevent this the tank (14) includes a portion which screens the field from reaching the developed image. Also, the screen includes a portion (5) so arranged that toner particles adhering to the screen portion (14) when released from the screen upon rotation of the magnets (12) are preferentially attracted to the sleeve (11) rather than being thrown onto the developed image on the photosensitive drum (10).