| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of being used with the level of greasing on an obtained image equal to or less than a certain level particularly even when toner concentration is high, against the variation in the toner concentration during use with the lapse of time. <P>SOLUTION: In the image forming apparatus using a two-component developer containing a carrier and toner and using a DC developing bias as a developing bias, the developer is used at initial toner concentration of 5-10% and the lower limit of the toner concentration is always ≥5%. Even when used at the toner concentration equal to or less than 1.5 times the initial toner concentration, the greasing density ΔID of a background part on a latent image carrier between a developing device and a transfer device is <0.01. <P>COPYRIGHT: (C)2007,JPO&INPIT |
