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DEP APPARATUS FOR SELECTIVELY CREATING MONOCHROME HIGHLIGHT COLOR OR PROCESS COLOR IMAGES

IP.com Disclosure Number: IPCOM000026231D
Original Publication Date: 1990-Dec-31
Included in the Prior Art Database: 2004-Apr-05
Document File: 6 page(s) / 383K

Publishing Venue

Xerox Disclosure Journal

Abstract

This invention relates to a Direct Electrostatic Printing (DEP) device and more particularly, to DEP wherein multiple printhead structures are employed for the selective printing of highlight color, process color or monochrome images.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 25% of the total text.

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XEROX DISCLOSURE JOURNAL

DEP APPARATUS FOR Proposed Classification SELECTIVELY CREATING U.S. C1.346/146 MONOCHROME HIGHLIGHT
COLOR OR PROCESS COLOR
IMAGES
Fred W. Schmidlin
Raymond W. Stover

Int. C1. Gold 09/00

706

I

42

2+-

XEROX DISCLOSURE JOURNAL - Vol15 No 6 NovembedDecember 1990 425

FIG. 1

[This page contains 1 picture or other non-text object]

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DEP APPARATUS FOR SELECTIVELY CREATING MONOCHROME HIGHLIGHT COLOR OR PROCESS COLOR MAGE S(Cont'd)

41

t

426 XEROX DISCLOSURE JOURNAL - Vol15 No 6 NovembedDecember 1990

[This page contains 1 picture or other non-text object]

Page 3 of 6

DEP APPARATUS FOR SELECTIVELY CREATING MONOCHROME HIGHLIGHT COLOR OR PROCESS COLOR IMAGES(Cont'd)

This invention relates to a Direct Electrostatic Printing (DEP) device and more particularly, to DEP wherein multiple printhead structures are employed for the selective printing of highlight color, process color or monochrome images.

The present invention provides a single pass color printer that utilizes a minimum number of parts making up the individual image forming members with a minimum degree of subsystem interaction.

The printer of the present invention comprises a vacuum drum for transporting image receiving sheets past a plurality of DEP printhead structures for selectively printing various types of images. For example, black only images, highlight color images or process color images may be printed. To this end there are provided a plurality of printheads each utilizing a different color toner. Each printhead structure may be selectively actuated depending upon whether its color is to be used in forming the final image. Thus, where a process color image is to be formed, all of the printheads are actuated and where black images are to be created only the black printhead is actuated.

The vacuum drum is provided with a plurality of vacuum chambers connected to a vacuum source. Porous sections are provided in the drum surface adjacent the chambers for tacking the image receiver sheets to the drum for movement past the plurality of printhead structures. Three of the chambers are provided for tacking the lead and trailing portions of the sheets to the drum. The remaining chamber is utilized to sequentially remove unwanted toner from the printhead structures. One of the chambers is also connected to a source of positive air pressure for lifting the lead edge of a receiver sheet from the drum so that it can be fed into the nip of a heat and pressure fuser.

Suitable timing marks are provided on the surface of the drum for actuating the printhead structures and the valves controlling the vacuum and positive pressure sources. A suitable sensor, for example, a light emitting diode (LED) and photodiode or photodetector diode is employed for deriving output signals from the timing marks for actuating the valves at the appropriate times and for enabling the printhead structures.

An Electronic Subsystem (ESS) processes information to be printed and cond...