Patent ID: 8204403

Claim:
A modular xerographic marking device system, comprising at least one modular xerographic marking device assembled from the following modular components: a common paper transport module containing paper path components that define a paper path through the modular xerographic marking device and convey a sheet of paper from a paper inlet to a paper outlet; an image output terminal cavity of fixed specified dimensions within the common paper transport module, the image output terminal cavity being exposed to a portion of the paper path; and two or more differently configured marking engines, each sized and configured to be provided and mounted within the image output terminal cavity of the common paper transport module to transfer marking material from the marking engine onto paper transported along the paper path, each of the different marking engines including at least one two-color IOI drum module including a) a first charging unit disposed along a rotatable photoconductive photoreceptor, wherein the first charging unit places a substantially uniform charge on the photoreceptor; b) a first exposure unit disposed along the photoreceptor downstream of the first charging unit, wherein the first exposure unit performs an image-wise exposure to the photoreceptor to produce a first latent electrostatic image on the photoreceptor; c) a first development unit disposed along the photoreceptor downstream of the first exposure unit, wherein the first development unit places a first marking material on the photoreceptor according to the first latent electrostatic image to produce a first toned image; d) a second charging unit disposed on the photoreceptor downstream of the first exposure unit, wherein the second charging unit places a substantially uniform charge on the photoreceptor; e) a second exposure unit disposed along the photoreceptor downstream of the second charging unit, wherein the second exposure unit performs an image-wise exposure to the photoreceptor to produce a second latent electrostatic image on the photoreceptor; and f) a second development unit disposed along the photoreceptor downstream of the second exposure unit, wherein the second development unit places a second marking material on the photoreceptor according to the second latent electrostatic image to produce a second toned image, wherein each of the at least one modular xerographic marking device is assembled from a combination of the common paper transport module and one of the marking engines mounted within the image output terminal cavity of the common paper transport module so that print media transported along the paper path can receive the first toned image and the second toned image from the photoreceptor from each two-color IOI drum module in a single transfer to produce a toned image on print media.