The present invention relates to electrostatographic copying and more specifically to an improved xerographic photoreceptor. The art of xerography, as originally disclosed by Carlson in U.S. Pat. No. 2,297,691, involves the uniform electrostatic charging of a plate comprised of a conductive substrate having a layer of a photoconductive material on its surface. This plate is normally referred to as the photoreceptor. Exposing the charged photoreceptor to a pattern of light and shadow dissipates the charge in the light struck areas leaving a latent electrostatic image corresponding to the shadow areas. The latent image is developed by contacting it with a particulate electroscopic marking material known as toner which adheres to the latent image and can be readily transferred to paper in imagewise configuration corresponding to the latent image. Since not all of the toner particles attracted to the latent image are transferred to the paper, a cleaning step is required to remove residual toner before the photoreceptor can be put through another cycle. This can be accomplished by the use of a rotating brush as the cleaning means. An alternative method involves the application of a flexible doctor blade to the photoreceptor, and providing relative motion between the blade and the plate. Experience with this method of cleaning toner has shown that the doctor blade is a simple, efficient and economical method of removing the residual toner from the photoreceptor surface and that the power requirements for this method are extremely low. The doctor blade method of cleaning the photoreceptor surface is more fully described in U.S. Pat. Nos. 3,438,706 to H. Tanaka et al.; 3,552,850 to S. F. Royka et al.; 3,634,977 to W. A. Sullivan; and 3,724,020 to Henry R. Till. While the blade method of cleaning has definite advantages over other cleaning methods, it has proven problematical in some instances due to friction between the photoreceptor surface and the blade causing the blade to chatter and occasionally fold over during the cleaning operation.
It is an object of the present invention to provide a novel electrostatographic photoreceptor suitable for cleaning with a thin edged doctor blade.
An additional object is to provide such a photoreceptor in which the friction between the doctor blade and photoreceptor surface is less than that observed with conventional photoreceptors.
A further object is to provide such a photoreceptor which when cleaned with a doctor blade is less subject to blade chattering and fold over than are conventional photoreceptors.
A further object is to provide such a photoreceptor which when cleaned with a doctor blade is less subject to abrasion than conventional photoreceptors.
USPTO Backgrounds
USPTO Backgrounds