| 摘要 |
PROBLEM TO BE SOLVED: To provide an image forming apparatus having a development unit which forms an extremely highly reliable, highly accurate image of high image quality without causing scattered toner even in use of developer containing toner of small particle-diameter. SOLUTION: The internal face of a development unit housing which faces a developer carrier includes a recess rounded face. A gap between the recess rounded face and the peripheral face of the developer carrier is set so as not to exceed a value calculated from a following computation expression: G=0.4120×1n(H)+0.2213×1n(D)+2.8596, wherein G is the maximum permissible gap dimension (mm), H is the magnetic flux density value (T) of the conveyance pole of a magnetic body, D is an amount (g/cm<SP>2</SP>) of developer conveyed by the developer carrier, and 1n is a natural logarithm. COPYRIGHT: (C)2005,JPO&NCIPI |
