| 摘要 |
PURPOSE:To accurately detect toner density with a simple structure by providing a black photoreceiver for detecting a regularly reflected light from a toner carrier and toner image and a color photoreceiver for detecting random reflected lights. CONSTITUTION:A photoreceiver 22c receives a regularly reflected light of a light emitting element 22a via a transfer intermediate element (toner carrier) 2 or a toner image 3. A photoreceiver 22d receives random reflected lights. If a black toner image is detected on the element 2, a detected value of the light of the photoreceiver 22c is reduced, and as the toner density is raised, it is gradually reduced. Accordingly, black toner density can be detected by detecting regularly reflected light by using the photoreceiver 22c. The reflected light of the color toner is random reflected light. If a color toner image is formed on the element 2, as the toner density is raised, the random reflection amount is increased, and a detected amount of the photoreceiver 22d is increased. Accordingly, the color toner density is detected when the random reflection light is detected by the photoreceiver 22d. |
