Overcoated electrophotographic imaging system

An electrophotographic imaging member comprising at least one photoconductive layer and an overcoating layer comprising a film forming continuous phase comprising charge transport molecules and finely divided charge injection enabling particles dispersed in said continuous phase, said overcoating layer being substantially transparent to activating radiation to which said photoconductive layer is sensitive, being substantially electrically insulating at low electrical fields, having a resistivity greater than about 10.sup.13 ohm-cm in the dark and comprising sufficient charge injection enabling particles whereby said charge injection enabling particles polarize in the dark in less than about 10.sup.-12 seconds and inject charge carriers into said continuous phase in less than about 10 microseconds in an electric field greater than about 5 volts per micrometer applied across said overcoating layer and said photoconductive layer and said charge injection enabling particles polarize in the dark in more than about 10.sup.-12 second and inject charge carriers into said continuous phase in more than about 10 microseconds in an electric field less than about 5 volts per micrometer applied across said overcoating layer and said photoconductive layer.

An electrophotographic imaging process comprising (a) providing an electrophotographic imaging member comprising at least one photoconductive layer and an insulating overcoating layer comprising a film forming continuous phase comprising charge transport molecules and finely divided charge injection enabling particles dispersed in said continuous phase, said overcoating layer having a thickness between about 1 micrometer and about 15 micrometers and being substantially transparent to activating radiation to which said photoconductive layer is sensitive and having an imaging surface spaced from said photoconductive layer, (b) contacting the side of said photoconductive layer spaced from said overcoating layer with a conductive substrate, (c) depositing in the dark a substantially uniform electrostatic charge on said imaging surface, and (d) applying a sufficient electric field across said electrophotographic imaging member to polarize said charge injection enabling particles whereby said charge injection enabling particles inject charge carriers into said continuous phase, said charge carriers are transported in the dark to and trapped at the interface between said photoconductive layer and said overcoating layer, and opposite space charge in said overcoating layer is relaxed by charge emission from said charge injection enabling particles to said imaging surface.