Patent ID: 6497984
Filing Date: 2002-12-24
Classification: G03G

Abstract:
An electrophotographic image forming method including electrostatic charging on a photoreceptor, imagewise exposing on the photoreceptor to form a latent image, developing the latent image by a developer containing a toner, transferring the developed toner onto an image forming material, and cleaning residual toner on the photoreceptor, wherein decrease &Dgr;Hd (in &mgr;m), in layer thickness per rotation in wear test of the organic electrophotographic photoreceptor defined below, is in the range of 0&lE;&Dgr;Hd<1Ã—10âˆ’5, and the toner is one which is obtained by suspension-polymerizing a polymerizable composition consisting of at least a polymerizable monomer and a colorant in a water based medium or one which is obtained by fusing resinous particles in a water based medium, said wear test comprising an electrophotographic photoreceptor connected to a driving section being brought into contact with a cleaning blade having a hardness of 70Â±1Â°, an impact resilience of 35Â±1 percent, a thickness of 2Â±0.2 mm, and a free length of 9Â±0.1 mm under conditions of a contact angle of 10Â±0.5 degrees in the counter direction and a thrust amount of 1.5Â±0.2 mm and while rotating said electrophotographic photoreceptor employing said driving section so that one rotation is completed within 0.1 to 10 seconds, toner particles having a volume average particle diameter of 8.5Â±0.5 &mgr;m, which was blended with powder having a number average particle diameter of 10 to 40 nm as the external additive, in an amount of 1Â±0.1 percent by weight with respect to said toner, was subjected to development so as to result in an adhered amount of 0.15Â±0.05 mg/cm2. After development, said toner particles were removed. When said electrophotographic photoreceptor was subjected to at least 100,000 rotations, the layer thickness variation amount of said photoreceptor was measured and the value obtained by dividing the resultant amount by the number of rotations was designated as the layer thickness decreasing amount per rotation.