| 摘要 |
PROBLEM TO BE SOLVED: To normally control image density based on density detection of the image for density detection by detecting soiling of a density sensor for detecting the reflected density of the image for density detection, formed on the surface of an intermediate transfer body and accurately detecting the density of the image for density detection. SOLUTION: In this image-forming device, a slit 42 is provided piercing through the surface of the intermediate transfer drum 9, an optical reflector 44 is provided inside this slit 42 in a position inside the transfer drum 9, and the optical reflection amount of the optical reflector 44 is measured by having it irradiated with infrared rays from a density sensor 40. A decision is made by a CPU 304 of a density control device that the density sensor 40 is soiled, when the soiling of the density sensor is progressed. This is when the sensor output is below the borderline, where the reference sensor output cannot be achieved even when compensation of the base is carried out. The user is notified of the soiling of the density sensor 40, and the cleaning of the density sensor is prompted. |
