| 摘要 |
PURPOSE:To detect a decrease in reflection intensity due to deterioration of carrier particles and to accurately detect an update period by providing a reflected light detecting means which detects the reflection intensity of a two- component developer. CONSTITUTION:Coating members are peeled off carrier particles as the carrier particles deteriorate, so the reflection intensity decreases. The reflected light detecting means which detects the reflection intensity of carrier particles in the developer consists of a light source 1 such as a tungsten lamp which emits white light, a lens 3 which converges the light from the light source 1 on a developer on a magnet roller 4, a lens 6 which converges the reflected light from carriers in the developer on a photoelectric converting member 2, and the photoelectric converting member 2. The photoelectric converting member 2 is connected to a control means such as a microcomputer and the update period is decided according to the reflection intensity. |
