Browse Prior Art Database

RASTER OUTPUT SCANNER

IP.com Disclosure Number: IPCOM000026241D
Original Publication Date: 1990-Dec-31
Included in the Prior Art Database: 2004-Apr-05
Document File: 8 page(s) / 393K

Publishing Venue

Xerox Disclosure Journal

Abstract

Multi-color electrophotographic printing is substantially identical to the process of black and white printing. However, rather than forming a single latent image on the photoconductive surface, successive latent images corresponding to the different colors desired in the copy are recorded. Each single color electrostatic latent image is developed with the appropriately colored toner. The single color toner images are transferred to the copy sheet in superimposed registration with one another. This creates a multi-layered toner image on the copy sheet. Thereafter, the multi-layered toner image is permanently affixed to the copy sheet creating a color copy.

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 24% of the total text.

Page 1 of 8

XEROX DISCLOSURE JOURNAL

RASTER OUTPUT SCANNER Proposed Classification Joseph Fantuzzo U.S. C1.355/218 Thomas Robson Int. C1. G03g 21/00

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FIG. I

XEROX DISCLOSURE JOURNAL - Vol15 No 6 NovembedDecember 1990 455

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

Page 2 of 8

RASTER OUTPUT SCANNER( Cont'd)

76 74 10

801

FIG. 2

456 XEROX DISCLOSURE JOURNAL - Vol15 No 6 NovembedDecember 1990

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

Page 3 of 8

RASTER OUTPUT SCANNER(Cont'd)

DETECT1 ON

 BEAM POSITION CONTROL

D ETECTIO N

I I

TRIGGERED OSCl LLATOR

TRIGGERED OSCl LLATO R

\ PHASE LOCKED LOOP

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96

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PIXEL CLOCK

TO DRUM MOTOR

98 BEAM

  TILT CONTROL

VOLTAGE '

CONTROLLED

 OSCl LLATOR AND SUMMER

 START OF SCAN ADJUST

SYSTEM

 TIMING CONTROL

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TO ACUSTOOPTIC

88 DEFLECTOR \

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ESS TO FIG. 3

XEROX DISCLOSURE JOURNAL - Vol15 No 6 NovembedDecember 1990 457

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

Page 4 of 8

RASTER OUTPUT SCANNER(Cont'd)

Multi-color electrophotographic printing is substantially identical to the process of black and white printing. However, rather than forming a single latent image on the photoconductive surface, successive latent images corresponding to the different colors desired in the copy are recorded. Each single color electrostatic latent image is developed with the appropriately colored toner. The single color toner images are transferred to the copy sheet in superimposed registration with one another. This creates a multi-layered toner image on the copy sheet. Thereafter, the multi-layered toner image is permanently affixed to the copy sheet creating a color copy.

A raster output scanner may be used to expose the charged portions of the photoconductive member to record the electrostatic latent image thereon. Generally, a raster output scanner has a laser for generating a collimated beam of monochromatic radiation. The laser beam is modulated in conformance with the image information. The modulated beam is reflected through a lens onto a scanning element, i.e. a rotating polygon having mirrored facets. The beam reflected from the polygon through a lens which focuses the scanning beam onto the charged portion of the photoconductive member. When a photoconductive drum is used, variations in the motion of the photoconductive member lead to the problem of banding in the image. Traditionally, this problem has been solved by an expensive drum servo system. In addition, in color printing machines, differences in eccentricity and out of roundness in drums can result in registration problems in tandem and multi-start single drum machines. Various types of control systems have been devised for regulating the velocity of a photoconductive drum.

Pursuant to the features of the present invention, there is provided a raster output scanner of the type in which a high intensity beam records images on a movable imaging member. A movable scanning element scans the beam across the imagi...