| 摘要 |
PURPOSE:To prolong the life of the device by providing a toner scraping member to a toner layer thinning control member made of a hard roller which is made stationary in image formation and driven to rotate except in the image formation. CONSTITUTION:The toner layer control doctor roller 7 which is driven to rotate at a relatively large linear speed excepting the image formation is formed of a hard roller member and installed while enabled to move reciprocally at right angles to the axis so as to contact and leave a developing roller 4. There fore, the roller floats above the surface of the developing roller 4 by the layer thickness of toner maintain a nearly constant contacting force to the developing roller 4. The front edge part of the scraping blade 10 is pressed against the surface of the toner layer control doctor roller 7 to clean toner sticking on the surface of the roller 7. Consequently, the life of the developing device is prolonged without making the device complex for causing an increase in its size. |
