Browse Prior Art Database

TONER STREAK DETECTION WITH IMPROVED RESOLUTION AND RELIABILITY

IP.com Disclosure Number: IPCOM000026765D
Original Publication Date: 1993-Aug-31
Included in the Prior Art Database: 2004-Apr-06
Document File: 4 page(s) / 211K

Publishing Venue

Xerox Disclosure Journal

Abstract

Disclosed is an improved economical method for detecting toner streaks on the surface of a photoreceptors. Figure 1 shows a prior art streak detection scheme in the known 'reflection' made. The improved method uses a cylindrical lens 1 positioned above the photoreceptor 2 which permits the formation of an electronic image of any streaks 3 on a sensitive area of a scanning phototransistor 4 having a scanning direction 5 perpendicular to the process direction and parallel to extended light source 6 as illustrated in Figure 2. As shown in Figure 2, 'transmission' mode detection, enables the detection of both thin and low density or low developer mass per unit area (DMA) toner streaks. The method is immune or unaffected by scratches and other blemishes on the photoreceptor surface, while maintaining a high level of sensitivity to toner streaks. The method has potential application in various subsystems in xerographic copiers and printers, particularly in detecting blade cleaner efficiency and failure.

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 44% of the total text.

Page 1 of 4

XEROX DISCLOSURE JOURNAL

TONER STREAK DETECTION WITH IMPROVED RESOLUTION AND U.S. C1.346/160 RELIABILITY Int. C1. Gold 15/00
N. Kedarnath Richard Aman Fred F. Hubble ILI

Proposed Classification

5 7-

y' 3 1

< / .

FIG. I

3

1

> , >

,1111111111111111

I I I I I I I I I I I I I I I I,

FIG. 2

XEROX DISCLOSURE JOURNAL - VO~. 18, NO. 4 July/August 1993 373

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

Page 2 of 4

TONER STREAK DETECTION WITH IMPROVED RESOLUTION AND RELIABILITY (Cont'd)

Disclosed is an improved economical method for detecting toner streaks on the surface of a photoreceptors. Figure 1 shows a prior art streak detection scheme in the known 'reflection' made. The improved method uses a cylindrical lens 1 positioned above the photoreceptor 2 which permits the formation of an electronic image of any streaks 3 on a sensitive area of a scanning phototransistor 4 having a scanning direction 5 perpendicular to the process direction and parallel to extended light source 6 as illustrated in Figure 2. As shown in Figure 2, 'transmission' mode detection, enables the detection of both thin and low density or low developer mass per unit area (DMA) toner streaks. The method is immune or unaffected by scratches and other blemishes on the photoreceptor surface, while maintaining a high level of sensitivity to toner streaks. The method has potential application in various subsystems in xerographic copiers and printers, particularly in detecting blade cleaner efficiency and failure.

The ability to detect fine toner streaks on the surface of a photoreceptor has several advantages. For example, most blade cleaner failures result in toner leaking past the blade. These failures result in long toner streaks on the photoreceptor and similar lines on prints or copies. If the toner streaks are detected in real time, a new blade can be automatically cammed in with very little disruption of electrophotographic processes. An auto-repair or self maintaining cleaner concept as mentioned above requires the ability to detect fine lines, for example, about 100 micrometers or larger in width, and light streaks. While there are several means to detect such streaks, most of the means are not cost effective nor reliable. Streak detection is also important in subsystems like image registration and photoreceptor steering.

Detection of toner streaks by optical means have been proposed earlier. Most of these techniques rely on detecting the streaks in the 'reflection' mode as illustrated in Figure 1. The surface of the photoreceptor is highly reflective, particularly for angles of grazing incidence. Hence, the light is reflected essentially nearly unattenuated. If the surface is covered by a thin layer of toner or other absorbing material, the reflected light is is strongly attenuated. A photodiode/transistor, monitoring the intensity of specularly reflected light, can be used as streak detector. Though reflective mode monitoring technique is simple, there a...