| 摘要 |
PURPOSE:To attain developing treatment reduced toner fogging to a non-image part and prevented from the sharp reduction of the density of an image part by combining prebath treatment with the application of reverse bias voltage. CONSTITUTION:A prebath treatment solution is supplied from a prebath treatment solution feeding pipe 1 to the image forming surface S of an electrophotographic sensitive body T on which a latent image is formed. The photosensitive body T is carried to a developing part consisting of a toner developer feeding unit 4, a developing electrode 5 and a back electrode 6 by carrying squeezing rollers 2A, 2B to form a toner image while the body T is controlled at the quantity of treating solution adhered to the surface. When the photosensitive body T enters into the toner developing part, a switch for a power supply 8 in a reverse bias voltage applying device 7 is closed and +30V reverse bias voltage is applied to the back electrode 6 against the grounded developing electrode 5. The electric field generated between the electrodes 5 and 6 is reversed to the electric field generated between the surface of the photosensitive body T and the electrode 5, so that the electric field intensity between the non-image part and the electrode 5 is weakened and the electrodeposition of toner to the non-image part is reduced.
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