Patent ID: 6379853
Filing Date: 2002-04-30
Classification: G03G

Abstract:
A tunable electrophotographic imaging member comprising:a substrate; an optional charge blocking layer; an optional adhesive layer; a charge generating layer; a charge transport element comprising a first charge transport layer and a sequentially deposited second charge transport layer; wherein each of the first and second charge transport layers comprises a hole transport material and optionally a film forming binder; wherein the first charge transport layer exhibits a first charge carrier transit time and the second charge transport layer exhibits a second charge carrier transit time; wherein either: (1) a different charge transport material is used for each of the first and second charge transport layers so that a charge mobility of the charge transport material of the first charge transport layer is about 4 to about 20 times less than a charge mobility of the charge transport material of the second charge transport layer; or (2) both the first and second charge transport layers are comprised of the same charge transport material and the first charge transport layer is comprised of an amount of charge transport material that is about 5% to about 30% less than an amount of charge transport material comprised by the second charge transport layer; and wherein a discharge surface potential of the imaging member at a light exposure greater than about 3 erg/cm2 at a post exposure delay of between about 20 milliseconds and about 500 milliseconds is raised from about 20 to about 200 volts above a discharge potential of an imaging member comprising each of the above components except having a single charge transport layer with a thickness that is equivalent to said charge transporting element.