| 摘要 |
PURPOSE:To suppress the fluctuation of the toner content in a mixture composed of a toner and carrier and to stabilize the application of frictional electrostatic charge to the toner by providing a cover with apertures to cover the surface of a developer holding member apart at a space therefrom. CONSTITUTION:The cover 26 is provided at the boundary between the developer part consisting of the carrier C and toner T and the part consisting of only the toner T in the upper part of a developer supplying container 14. The cover 26 consists of a nonmagnetic metal or resin such as polyester and has the apertures sized approximately equal to the size of the carrier, of which the rate of perforation is >=35%. The carrier C parts from the cover 26 and the toner T moves near to a nonmagnetic sleeve 11 which is the developer holding member through the apertures of the cover 26 if the toner content of the developer retrained on the sleeve 11 is low. The toner content in the developer is thereby increased. The carrier C advances into the apertures of the cover 26 to thoroughly isolate the developer and the toner T in the hopper part when the volume of the developer increases to an adequate concn. or above. The toner content of the developer is thus decreased. |
