Delmer G. Parker

Single-pass highlight color electrophotography

Single-pass highlight color printers (black plus one color) are advantaged over multi-pass systems in that image throughput is not sacrificed in obtaining the additional color. Furthermore, single exposure systems are advantageous since perfect registration is inherently assured. In this paper we will review several approaches to single-pass highlight color systems and then focus on the recently announced Xerox highlight color printer.© (1992) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Development of trilevel xerographic images

One exposure, trilevel xerography provides a novel means to produce, single pass, highlight color prints. In this scheme, a ROS creates an imagewise three level, unipolar latent image in which the color information is encoded in the discharge level. The highest charge regions represent one color, and the lowest charge regions a second color. An intermediate charge level, approximately midway between the high and low charge, serves as the background reference and is not printed. The components of the composite two color latent image are developed sequentially using charged area and discharged area development and bipolar developers. Electrostatic transfer is enabled by converting the developed bipolar image to a unipolar image using a pretransfer charging step. Because of the nature of the latent image, a trilevel development system must satisfy demands substantially beyond those required in conventional xerography. This paper will discuss these requirements.© (1992) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.