| 摘要 |
PROBLEM TO BE SOLVED: To provide a developing device in which it is not necessary to dispose a contact member for triboelectrically charging toner existing on a developing roller, and which allows formation of a high quality toner image free of density unevenness in a low contrast image which follows an image partly having a solid image, and to provide a printer and an image forming process unit. SOLUTION: The developing device has the developing roller 402 which bears toner and a magnetic brush roller 403 which bears a two-component developer 12, carries it to a toner supply region A2 and supplies only a toner 10 from the developer 12 to the developing roller 402, wherein conditions in toner supply by the magnetic brush roller 403 are set so that when a surface of the developing roller not bearing the toner passes once through the toner supply region A2, the maximum bearing amount of the toner per unit area of the developing roller surface is supplied and borne on the developing roller surface. COPYRIGHT: (C)2007,JPO&INPIT |
