| 摘要 |
PURPOSE:To make stable toner replenishing possible by providing means of detecting the control image of a black color provided in the white background part for forming a control latent image of constant potential on the surface of a photoreceptor and the amt. of the toner stuck on said control latent image after developing. CONSTITUTION:A subcharger 2, a previous history exposure lamp 3, a main charger 4, a developing device 5, a light emitting device 17 and a photodetector 18 for detecting the amt. of the toner stuck on a control latent image, a cleaner plate 19, etc. are installed around a photosensitive drum 1. A control image 29 of a black color as a reference pattern is provided in the white background part forming the control latent image of constant potential on the drum 1 and is developed. In this case, the photodetector 18 detects the reflected density of the control latent image and controls a replenishing roller driving mechanism. Therefore, it is possible to control toner replenishment in correspondence accurately to the toner concn. in the device 5 and the replenishment of the toner is stabilized. |
