Electrophotographic imaging method having a double charging sequence

Claim 1

An electrophotographic imaging method comprising: (a) providing a photoreceptor comprising in the stated order (i) a substrate; (ii) a layer of a charge carrier injecting material capable of injecting one species of charge carrier into the transport layer described in (iii) below in the presence of an electrical field and in the absence of illumination; (iii) a layer of a charge carrier transport material capable of transporting at least one species of charge carrier and injecting one species of charge carrier into the layer of charge carrier generating material described in (iv) below; (iv) a layer of charge carrier generating material which is capable of injecting photogenerated charge carriers of one species into said charge carrier transport material, subject to the provision that the charge carriers travel across the interface between the transport and generating layer in both directions; and (v) a layer of electrically insulating material; (b) charging said photoreceptor with electrostatic charges of a first polarity; (c) charging said photoreceptor with electrostatic charges opposite in polarity to said first polarity in order to substantially neutralize the charges residing on the surface of said photoreceptor; and (d) exposing said photoreceptor to an imagewise pattern of electromagnetic radiation to which said charge carrier generating material is responsive whereby there is formed an electrostatic latent image within said photoreceptor.