US Patent 7471924 Cleaning unit and image forming apparatus

This invention relates to a cleaning unit including a cleaning blade that keeps a front end of rubber material in contact with the surface with a pressure so as to scrape residual toner left on the surface of the photoreceptor and a fiber body having multiple fibers in contact with the surface of the photoreceptor in the upstream in the cyclic moving direction of the surface of the photoreceptor with respect to the cleaning blade, the cleaning blade satisfying A≧−2.5×B+102 and 6.3≦B≦19.6, where A designates a contact angle (°) with pure water under 23° C., 55% RH and B designates 100% modulus (MPa) at 23° C.