Patent ID: 6181901
Filing Date: 2001-01-30
Classification: G03G

Abstract:
A multicolor image-on-image reproduction machine comprising:(a) a main assembly including a movable image bearing member having a path of movement, a controller, and a bias source for biasing said image bearing member to receive and carry toner images;(b) a plurality of reverse charge printing (RCP) imaging units mounted along said path of movement of said image bearing member, each (RCP) imaging unit of said plurality thereof including:(i) a movable photoreceptor including a photoconductive surface forming a toner image separation development nip with said movable image bearing member;(ii) a toner supply apparatus for applying a layer of toner particles having a particular color onto said photoconductive surface of said photoreceptor;(iii) a first charging device for uniformly charging said photoconductive surface;(iv) an exposure device, connected to said controller and mounted downstream of said first charging device, relative to movement of said photoreceptor, for image-wise exposing photoconductive surface and said layer of toner particles to form therein image areas and background areas of a desired image; and(v) a second charging device connected to said controller for selectively recharging the background areas of the desired image in said layer of toner particles, so as to enable separation of said background areas from said image areas of the desired image;(d) separation development means for separating and developing said image areas of the desired image from said layer of toner particles on said photoconductive surface of said photoreceptor onto said image bearing member of said main assembly, to form a multicolor toner image; and(e) an image stabilization unit mounted downstream of each said image separation development nip, relative to movement of said image bearing member, and interacts with said color separation toner image, for increasing a toner layer strength of said color separation toner image prior to subsequent transfer onto said image bearing member of another color separation toner image, said image stabilization unit including a pressure roller and a charging unit.