| 摘要 |
PURPOSE:To correctly stabilize the density of a copy image by forming a stepwise potential distribution of two stages or more on a photosensitive body by an image exposure of a standard reflecting plate, radiating light on an obtained toner pattern and photodetecting its reflected light by a second photodetector, and control ling said light based on its result. CONSTITUTION:A standard reflecting plate 40 having reflection density of one kind or more is provided in the vicinity of original glass of a copying machine, lamp- reflected light by the standard reflecting plate 40 is led to a first photodetector 50 by an image forming optical system and photodetected, and by controlling the light quantity of a lamp, based on its result, the exposure quantity is adjusted automatically. Also, by an image exposure of the standard reflecting plate 40, a stepwise potential distribution of two stages or more is formed on a photosensitive body, light radiation is executed on a toner pattern obtained by developing this potential distribution and its reflected light is photodetected by the second photodetector 60, and based on its result, a charging current of the photosensitive body or a toner replenishment quantity is controlled. In such a way, the exposure quantity is adjusted automatically by controlling the lamp light quantity by a result of photodetection of the first photodetector 50, therefore, it does not occur that a variation of the density of the toner pattern is generated due to the exposure quantity. |
