DEVELOPING DEVICE AND PROCESS CARTRIDGE

摘要

PURPOSE:To relieve unequal electrostatic charge of a developer and to obtain images having high quality by good development by specifying the amt. of the developer applied on a developer carrying member within a specific range. CONSTITUTION:A developing sleeve 8 is formed by an aluminum drawn pipe and the surface of this sleeve is subjected to a sandblasting treatment utilizing random abrasive grains. A magnet 18 for holding the magnetic developer 6 on the sleeve surface is installed in this developing sleeve 8. A developing bias power source 19 is connected to the developing sleeve 8 and a developing bias is impressed between the developing sleeve 8 and a photosensitive drum 2. The amt. of the developer to be applied per unit area on the developing sleeve 8 which is the developer carrying member is so adjusted as to be 0.6 to 1.5mg/cm<2>. The unequal densities by a coating defect are conspicuous if this amt. is below 0.6mg/cm<2> and inversion fogging arises if the amt. is above 1.5mg/cm<2>.