Dismiss
InnovationQ will be updated on Sunday, Oct. 22, from 10am ET - noon. You may experience brief service interruptions during that time.
Browse Prior Art Database

LIGHT SHIELD FOR FLASH FUSER

IP.com Disclosure Number: IPCOM000014520D
Original Publication Date: 2000-Aug-01
Included in the Prior Art Database: 2003-Jun-19
Document File: 2 page(s) / 87K

Publishing Venue

IBM

Abstract

Disclosed is a device that blocks stray light from a flash fuser from impinging on the photoconductor in an electrophotographic printer. The device or light shield is an electrically biased conductive roller that rolls on the paper path, in contact with the unfused image, to block the light path between the flash fuser and the photoconductor. At minimum such a device must reduce the amount of light reaching the photoconductor below the threshold where a print quality defect is created without disturbing the unfused image on the print. Figure 1 illustrates an electrophotographic process with a flash fuser. The paper enters from the right side and the toned image is transferred from the photoconductor to the paper. The toned image on the paper then moves to the flash fuser where the flash output of a xenon lamp fuses the toner to the paper. There is a gap between the flash fuser and the paper so that the unfused image is not disturbed by contact with the fuser. The gap between the fuser and paper allows some light to escape the fuser; if this light impinges on the photoconductor, a smudge-like defect will result on the print. To minimize the amount of light that reaches the photoconductor, a guide may be added. A gap must be maintained between the guide and the paper to prevent the toned image from being smudged by contact. There is still a fraction of light that will pass through the gap between the guide and the paper, reaching the photoconductor and causing a print defect. Figure 2 illustrates the use of a roller between the flash fuser and the guide to block all light from the fuser. The roller is lightly loaded and rides on the surface of the toned image on the paper. To prevent the toned image from being smudged or transferring to the roller, the roller is electrically biased such that the electric field between the roller and the paper keeps the charged toner on the paper. To further enhance the electric field, the paper transport mechanism may have a bias voltage applied opposite in polarity from the roller. The roller may be coated with a non-stick material to help prevent any toner from adhering to the roller. Figure 1

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 65% of the total text.

Page 1 of 2

LIGHT SHIELD FOR FLASH FUSER

   Disclosed is a device that blocks stray light from a flash fuser from
impinging on the photoconductor in an electrophotographic printer. The device or
light shield is an electrically biased conductive roller that rolls on the paper
path, in contact with the unfused image, to block the light path between the
flash fuser and the photoconductor. At minimum such a device must reduce the
amount of light reaching the photoconductor below the threshold where a print
quality defect is created without disturbing the unfused image on the print.

   Figure 1 illustrates an electrophotographic process with a flash fuser. The
paper enters from the right side and the toned image is transferred from the
photoconductor to the paper. The toned image on the paper then moves to the
flash fuser where the flash output of a xenon lamp fuses the toner to the paper.
There is a gap between the flash fuser and the paper so that the unfused image is
not disturbed by contact with the fuser. The gap between the fuser and paper
allows some light to escape the fuser; if this light impinges on the
photoconductor, a smudge-like defect will result on the print. To minimize the
amount of light that reaches the photoconductor, a guide may be added. A gap
must be maintained between the guide and the paper to prevent the toned image
from being smudged by contact. There is still a fraction of light that will pass
through the gap between the guide and the paper, reaching the photoconductor and
c...