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REDUNDANCY TO IMPROVE PHOTORECEPTOR SEAM DETECTION

IP.com Disclosure Number: IPCOM000027823D
Original Publication Date: 1999-Dec-31
Included in the Prior Art Database: 2004-Apr-09
Document File: 1 page(s) / 62K

Publishing Venue

Xerox Disclosure Journal

Abstract

Disclosed is the use of a redundant measurement for photoreceptor seam passage in electrophotographic printers and copiers by utilization of coincident signals from an optical density sensor and an electrostatic voltage sensor.

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XEROX DISCLOSURE JOURNAL

REDUNDANCY TO IMPROVE Proposed Classification PHOTORECEPTOR SEAM DETECTION
U. Jeffrey J. Folkins S. C1. 399/116
Int. C1. G03g 15/02

Disclosed is the use of a redundant measurement for photoreceptor seam passage in electrophotographic printers and copiers by utilization of coincident signals from an optical density sensor and an electrostatic voltage sensor.

Just as the photoreceptor seam provides a characteristic optical density signal for sensor detection, the seam provides a characteristic spike in an electrostatic voltage response after charging that is measurable with an electrostatic voltmeter. Therefore, it is possible to use similar techniques to measure the seam with an electrostatic voltmeter as with an optical density sensor. Using the fact that both sensors are capable of measuring the seam independently, a valid seam measurement is declared only when both sensors detect coincident signals.

Having two measurements of seam presence greatly reduces the chance of false signals particularly those generated by random noise. Additionally, if a spurious seam signal originates from some fixed photoreceptor defect like a scratch then, it is possible to take advantage of an additional feature of the optical density sensor/electrostatic voltage pair. Since the physics of the optical density and the electrostatic voltage variation are completely different it is much less likely that the defect scratch that produces a signal at one sensor w...