Browse Prior Art Database

LIGHT PIPE EDGE ERASE FOR USE WITH LASER SCANNING SYSTEMS

IP.com Disclosure Number: IPCOM000026155D
Original Publication Date: 1990-Aug-31
Included in the Prior Art Database: 2004-Apr-05
Document File: 4 page(s) / 175K

Publishing Venue

Xerox Disclosure Journal

Abstract

Very high precision, very high copy quality laser scanning systems may require scan line lengths which are less than the process width to be cost effective. These systems will also require an edge erase device. The function of the edge erase device is to reduce the charge on the photoreceptor to the background level. Very high copy quality systems may have low development latitudes. In these cases the exposure and alignment of the edge erase device must be precisely adjusted. Exposure adjustments is required to avoid toner or bead development. Alignment is required to "stitch" the ROS and edge erase devices exposures such that there is limited overlap and no void. Overlap can cause bead development. A void will cause toner development. Toner development will contaminate the process with dirt. Bead development will damage the photoreceptor and cleaner, and deplete developer from the sump.

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XEROX DISCLOSURE JOURNAL

Proposed Classification

LIGHT PIPE EDGE ERASE FOR USE WITH LASER SCANNING U.S. C1.355/210 SYSTEMS Int. C1. G03g 15/00 Michael A. Parisi

10

/ Photoreceptor Motion

FIG.l

XEROX DISCLOSURE JOURNAL - VO~. 15, NO. 4 July/August 1990 239

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LIGHT PIPE EDGE ERASE FOR USE WITH LASER SCANNING SY STEMS(Cont'd)

Positive output

dtl

4 Amplifier) Integratory

Negative output

20 I- Switch:

om parator

Up for Laser Exposure Down for LED exposure

Exposure from LED

FIG. 2

Intensity

Voltage

Integrator Voltage


Exposure from Laser

r-----

Time

I*- Time for one scan line-1

FIG. 3

240 XEROX DISCLOSURE JOURNAL - Vol. 15, No. 4 July/August 1990

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LIGHT PIPE EDGE ERASE FOR USE WITH LASER SCANNING SY STEMS(Cont'd)

Very high precision, very high copy quality laser scanning systems may require scan line lengths which are less than the process width to be cost effective. These systems will also require an edge erase device. The function of the edge erase device is to reduce the charge on the photoreceptor to the background level. Very high copy quality systems may have low development latitudes. In these cases the exposure and alignment of the edge erase device must be precisely adjusted. Exposure adjustments is required to avoid toner or bead development. Alignment is required to "stitch" the ROS and edge erase devices exposures such that there is limited overlap and no void. Overlap can cause bead development. A void will cause toner development. Toner development will contaminate the process with dirt. Bead development will damage the photoreceptor and cleaner, and deplete developer from the sump.

An erase device 10 which uses both the scanning laser beam and a LED to supply the erase exposure is shown in Figure 1. The light page edge erase device 10 consists of a: Light Pipe 12; Photo diode 14; LED 16; and Electronic Circuit 20 (Figure 2). The light pipe 12 is mounted a small distance above a photoreceptor 14 such that a scanning laser beam will traverse and illuminate a window in the top of the light pipe. Its function is to spatially integrate the energy from the scanning laser and a LED 16, providing a uniform exposure on the photoreceptor. This uniform exposure may be accomplished varying the size of the surface exposed to the photoreceptor. A shaped aperture can be used or the photore...