| 摘要 |
PROBLEM TO BE SOLVED: To provide an image forming apparatus in which toner concentration, which varies accompanying toner consumption/supply, can be correctly followed by the provision of a detection developer carrier and a toner concentration detecting device, which is therefore easy to dispose, is provided. SOLUTION: A detection magnetic brush carrying roller 71 as the detection developer carrier is disposed at a specific part of a developing unit 61. The detection magnetic brush carrying roller is the one in which a magnetic roller 71a having two or more magnetic poles is rotatably covered with a sleeve 71b and which forms on its surface a developer layer for detecting a toner concentration. In addition, an optical sensor 72 as the toner concentration detecting device is located above the detection magnetic brush carrying roller. The concentration of toner in the developer carried by the detection magnetic brush carrying roller is detected with the optical sensor. COPYRIGHT: (C)2004,JPO |
