| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of comprehending the deterioration level of a carrier in a developer tank and preventing carrier sticking, background contamination, image quality deterioration or the like caused by a carrier deterioration. <P>SOLUTION: The image forming apparatus comprises an image carrier 1, a charging apparatus 2 for charging the image carrier 1, a developing apparatus 3 for supplying a two-component developer containing toner and carrier to the image carrier 1 and visualizing an electrostatic latent image, and an optical sensor 7 arranged oppositely to the image carrier 1 and provided with a light emitting element and a light receiving element comprises. The image forming apparatus also comprises: a detection means for developing the carrier in the developer onto the image carrier 1 while controlling a charging bias and a developing bias, detecting the reflected light quantities of a ground part and a carrier adhesion part of the image carrier 1 by the optical sensor 7, finding out the ratio of both the reflected light quantities, and comparing the ratio with a previously set reference value to detect the carrier adhesion quantity on the image carrier 1; and a control means for determining and controlling the discharge quantity of the developer from the developer tank and the feeding quantity of the carrier or the developer in accordance with the deterioration level of the carrier. <P>COPYRIGHT: (C)2007,JPO&INPIT |
