PHOTOSENSITIVE BODY FOR POSITIVE ELECTROSTATIC CHARGE

摘要

PURPOSE:To make possible the formation of an always satisfactorily visible image by using a granular material having the photosensitivity in the negative electrostatic charge stage higher than the sensitivity in the positive electrostatic charge stage and specifying the respective content ratios between such carrier generating material and binder material and between a carrier transfer material and binder material. CONSTITUTION:The electrons generated by the irradiation of light after the positive electrostatic charge of a photosensitive body having a photosensitive layer 4 consisting of mixed phases 6 with the carrier transfer material drift at a high speed to the surface and the positive charge on the surface attenuates substantially when the carrier generating material 7 having the sensitivity higher when the photosensitive body having the photosensitive layer consisting of said carrier generating material alone is charged negative than when said body is charged positive is used. The material 7 is incorporated at 20-50% with respect to the binder material and if the material 7 is incorporated at the lower ratio than said range, the photosensitivity is poor and the residual potential increases too much. The decrease in acceptive potential is high when said material is incorporated at the ratio higher than said range. The content of the carrier transfer material is made preferably 20-200% with respect to the binder material. The residual potential and photosensitivity are deteriorated when the carrier transfer material is incorporated at the lower ratio than said range and the solubility in solvent is poor if said material is incorporated at the ratio higher than said range.