PURPOSE: To transfer a toner image with excellent transfer efficiency for a long time by calculating image density on a photosensitive body or a transfer paper based on the data detected by an optical system detector and correcting impressed voltage on a transfer charger.
CONSTITUTION: The controller is provided with the optical system detector 2 which optically detects the image density of the toner image on the photosensitive body 1 or the transfer paper 14 after the toner image is transferred to a transfer paper 14 and a protection mechanism 3 which allows the light projecting and receiving part of the optical system detector to be opposed to the photosensitive body 1 or the transfer paper 14 directly at the time of detecting the image density and prevents dust from being scattered to the light projecting and receiving part at the time of not detecting the image density. When a copying action is executed proper times, the protection mechanism 3 is actuated and the image density of the toner image on the photosensitive body 1 or the transfer paper 14 is calculated based on the data detected by the detector 2, then the value of the impressed voltage on the transfer charger 13 is corrected based on the image density. Thus, the toner image is transferred to the transfer paper 14 with the excellent transfer efficiency.
NISHINO TOSHIO
YOSHIDA WATARU
| JPS5387739A | 1978-08-02 | |||
| JPS60143361A | 1985-07-29 |