# US 5,351,070 A · Single pass color printer having improved process and slow registration

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- Number: US 5,351,070 A
- Document ID: US5351070A
- Status: Granted
- Kind: A
- Application number: 07/825,463
- Filed: 1992-01-24
- Granted: 1994-09-27
- Earliest claimed: 1992-01-24
- Assignees: Xerox Corporation
- Inventors: John H. Hinton; William J. Nowak; Daniel W. Costanza
- Web page: https://patentgrep.com/patent/US5351070A

## CPC

- H04N 1/506: {Reproducing the colour component signals picture-sequentially, e.g. with reproducing heads spaced apart from one another in the subscanning direction}
- G06K 15/129: {Colour printing}
- H04N 1/0473: {in subscanning direction, e.g. picture start or line-to-line synchronisation}
- H04N 1/1135: {for the main-scan only}
- H04N 1/12: using the sheet-feed movement {or the medium-advance or the drum-rotation movement} as the slow scanning component, {e.g. arrangements for the main-scanning}({sheet-feed movement by translatory movement of a flat picture-bearing surface H04N1/1008; main-scanning using oscillating or rotating mirrors H04N1/113; } using multi-element arrays H04N1/19)
- H04N 2201/04762: using a reflecting element (H04N2201/04765 takes precedence)
- H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION
- G06K: GRAPHICAL DATA READING (image or video recognition or understanding G06V); PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS

## Abstract

A single pass highlight color printer is disclosed which utilizes two pairs of Raster Output Scan (ROS) systems mounted symmetrically about a common polygon motor assembly. Four identical optical systems are thus provided, 180.degree. apart with diode laser outputs directed from a ROS frame parallel and separated to allow the appropriate spacing for xerographic components situated adjacent the xerographic belt. Each ROS unit includes a 90.degree. mirror pair which is mounted on a roof mirror carriage which in turn is connected to a focus carriage via a flexible guide system. The interaction between the focus carriage and the roof mirror carriage enables a skew alignment and process (beam steering) adjustment to be accomplished with a high degree of precision.

## Claims

### Claim 1

An imaging system for forming image exposure frames on a photoreceptor belt moving in a process direction during a single pass including:
a plurality of Raster Output Scanners (ROS) units, each ROS unit generating image-modulated scan lines which are transmitted along an optical path to form said image exposure frames, said ROS units located in a common housing and positioned symmetrically on opposite sides of two polygon scanners mounted vertically on a common rotating shaft, said ROS units each comprising:
a diode laser for generating a beam output,
means for modulating the beam output of said laser with input video data,
optical means for collimating and expanding the modulated laser beam output and directing the collimated and expanded output against an associated polygon scanner,
post polygon lens group for correcting f.theta. and distortion in the reflected beam thereby producing a corrected scanning beam,
a 90.degree. roof mirror assembly mounted on a movable mirror carriage which folds the corrected scanning beam from the post polygon lens group in a 180.degree. path reversal and
a folding mirror for directing the corrected scanning beam out of the common housing and onto the photoreceptor belt, each scanning beam being parallel to each other,
the improvement wherein said roof mirror carriage is integrally mounted to a focus carriage and secured to the common housing at a position providing an optically focused scan line at the photoreceptor belt surface, means for incrementally moving, said roof mirror carriage to provide a skew registration correction to the scan line at the photoreceptor belt surface, and to provide a process registration direction correction to the scan line at the photoreceptor surface;

### Claim 2 (depends on 1)

The system of claim 1 wherein said focus and mirror carriages are connected via a guide system which maintains the connection between the focus and mirror carriages while said skew and process registration corrections are being provided.

### Claim 3 (depends on 2)

The system of claim 2 wherein said guide system includes a plurality of protuberances affixed to the focus carriage, a plurality of matching spherical nubs affixed to the mirror carriage, said nubs maintaining sliding contact with said protuberance surfaces while said skew and process registration correction are being provided.

### Claim 4 (depends on 3)

The system of claim 3 further including a plurality of springs fixedly attached to the focus and mirror carriage.

### Claim 5 (depends on 1)

The system of claim 1 wherein said diode laser arrays on each side of the polygon scanner are mounted in a lens barrel assembly which also houses the collimating optical means.