| 摘要 |
PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of accurately detecting toner concentration within a developing device regardless of a charging amount of toner.SOLUTION: The present invention is applicable to an image forming apparatus including an image carrier, and a developing device which stores a two-component developer including toner and carrier, and is provided with a developing roller. The image forming apparatus of the present invention comprises: an image density detection part which detects an image density of a toner image developed by the developing device; and a toner concentration detection part which executes a toner concentration detection mode for detecting toner concentration within the developing device. The rotation speed of the developing roller is made slower at time of executing the toner concentration detection mode than at time of a normal image formation, and a test image is developed by the developing device. In addition, the image densities of the test image are detected by the image density detection part, and density integration information is calculated which is an index amount of the toner concentration, by integrating the detected values. |
