| 摘要 |
PURPOSE:To provide a developing device having a blade durable against abrasion and a function for controlling thickness of a toner layer stabilized for a long term, by subjecting the end of the blade in contact with a developing sleeve to hardening treatment, such as nitriding treatment. CONSTITUTION:A developing sleeve 7 comprises a nonmagnetic conductive sleeve 7a, such as a stainless steel sleeve, a conductive rubber layer 7b, such as a silicone rubber layer having <=10<8>ohm.cm formed on the outer circumference of the sleeve 7a. A doctor blade 11 extending nearly in the normal direction is arranged on the sleeve 7, and it is pressed toward the sleeve 11 with a spring 13 provided between the casing 12 of a developing device and the blade 11. It is preferably made of a nonmagnetic material, and the end 14 of the blade 11 is made of the same material as that of the main body of the blade 11, but it is subjected to hardening treatment, such as nitriding treatment of 0.1mm. depth from the surface and giving hardness of Hv 1,100-1,400, considering abrasion due to toner. |
