Browse Prior Art Database

MASTER CLOCK FOR REGISTRATION SYNCHRONIZATION

IP.com Disclosure Number: IPCOM000026941D
Original Publication Date: 1994-Aug-31
Included in the Prior Art Database: 2004-Apr-07
Document File: 2 page(s) / 85K

Publishing Venue

Xerox Disclosure Journal

Abstract

Slow scan registration is required in a color printing system to insure that different color images forming a composite print are properly aligned. In the printing system image registration problems may result when the polygon rotation of the raster output scanner (ROS) is not synchronous with the photoreceptor belt or drum speed. Image registration errors occur when the different color images forming the composite image are placed on top of each other as the photoreceptor (PR) belt or drum moves in relation to the polygon of the ROS.

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XEROX DISCLOSURE JOURNAL

MASTER CLOCK FOR REGISTRATION SYNCHRONIZATION Aron Nachman Michael S. Cianciosi

Proposed Classification
U.S. C1.2711230
Int. C1. B65h 09/14

I

7

MASTER CLOCK CRYSTAL OSCILLATOR 12

DIVIDED PIXEL CLOCK

 GATE
ENABLE
BY N' b

10

sos

DIVIDED PHASE POLY CON

LOCKLOOP MOTOR

9 ENCODER FEEDBACK 6

'BELT or

+ DRUM

MOTOR

ENCODER FEEDBACK

8

BY N"

DIVIDED PHASE

BY N"' LOCKLOOP

TO OTHER

 MACHINE FU NCTIONS

XEROX DISCLOSURE JOURNAL - Vol. 19, No. 4 July/August 1994 269

[This page contains 3 pictures or other non-text objects]

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MASTER CLOCK FOR REGISTRATION SYNCHRONIZATION

(Cont'd)

Slow scan registration is required in a color printing system to insure that different color images forming a composite print are properly aligned. In the printing system image registration problems may result when the polygon rotation of the raster output scanner (ROS) is not synchronous with the photoreceptor belt or drum speed. Image registration errors occur when the different color images forming the composite image are placed on top of each other as the photoreceptor (PR) belt or drum moves in relation to the polygon of the ROS.

Disclosed is an apparatus that synchronizes the PR belt or drum with the polygon motor of a ROS in a printing system to eliminate DC registration errors. The apparatus shown in the Figure uses common reference clock 2 to synchronize polygon motor 4 with PR belt or drum motor 6, assuming each motor has phase locked loops 5 and 7, respectively...