JPS54147041A - Negative-positive recording method - Google Patents

Abstract

PURPOSE: To form negative or positive electrostatic images as desired by the use of one kind of one-component type non-magnetic toner by using a photoreceptor having a photoconductive layer and a transparent insulation layer and letting the same be charged by the specific method then developing the same.

CONSTITUTION: A photoreceptor 1 which comprises laminating a photoconductive layer 11 and a transparent insulation layer 12 on a conductive substrate 10 is used and this is primary-charged in a bright place, whereby the front side of the insulation layer 12 is made positive and the back side negative. Next, in the case of forming positive electrostatic images, secondary charging of negative polarity is applied to completely erase the positive charges of the surface of the insulation layer 12. Next, position selective exposure (image exposure) is performed to make the potentials of the photoreceptor 1 surface nearly zero in the exposed part and negative in the non-exposed part, after which the images are developed by the non- magnetic toner which has been forcefully charged positive. In the case of forming negative images, secondary charging of negative polarity is so applied that moderate positive charges remain on the insulation layer 12 surface, after which image exposure is performed to make the potentials of the photoreceptor 1 surface positive in the exposed part and nearly zero in the non-exposed part, thence the images are developed by the non-magnetic toner which has been forcefully charged negative.

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