Xerox Corporation

Christopher A Dirubio

Paul J McConville

Aaron Michael Burry

Palghat Srinivas Ramesh

Eric Scott Hamby

Peter Paul

Michael F Zona

Gerald M Fletcher

Eliud Robles Flores

Donald M Bott

Martin Krucinski

Bruce J Parks

William C Dean

Fei Xiao

Robert J Mead

A xerographic marking engine adjusts a charging actuator, such as an AC peak-to-peak voltage or an AC peak-to-peak AC current, based upon toner patch density measurements made using, e.g., a toner patch density sensor. The sensor is used to detect a knee in a toner mass density curve obtained by sweeping an AC peak-to-peak voltage or an AC peak-to-peak current. Once the knee is located, an AC charging actuator peak-to-peak voltage or AC peak-to-peak current is determined that reduces the amount of positive charge that is deposited onto the surface of the photoconductor, thereby extending its life while maintaining acceptable print quality. The described approach may improve photoconductor life without significantly increasing production costs or complexity.

Mass-based sensing of charging knee for active control of charger settings

Charging devices, electrostatic imaging devices, and methods generate a charging waveform having a DC bias component and an AC component for charging the imaging surface of a charge retentive member, the AC component having a substantially squarewave waveform.

Squarewave charging of a photoreceptor

The life of the photoconductor in an image forming apparatus is typically limited by the eventual occurrence of some form of print quality defect related to the photoconductor. One of the typical failure mechanisms is the slow wearing away of the surface layer of the photoconductor. Photoconductor run life is improved by operating a charging station in a low wear mode during certain circumstances, including: during printing of a low stress page as detected based on the image data; during at least one of cycle up and cycle down operations to control charging of the at least one photoconductor over at least one print zone for at least one cycle of rotation of the at least one photoconductor; during printing of at least one test patch in a process control cycle; and upon determination from the image data that at least one photoconductor will not contribute to the printing during a next print cycle.

Method and system for improving electrophotographic run cost through cyclic efficiency of the charging device

A defect analysis system for a xerographic print engine includes a residual mass sensor that senses the two-dimensional signature structure of residual mass remaining on a photoconductive or other substrate surface after image transfer. Preferably, the sensor is a full width array that spans substantially an entire width of the photoconductive surface. This information is then processed and analyzed to determine a specific type of transfer defect present. This may include the quantified level of defect for each detected type. The defect analysis system may also include a closed-loop control system that can adjust various xerographic process parameters using feedback based on the identification and optionally magnitude of each specific defect type. The identified print quality defect, such as mottle, streaks, point deletions, graininess, etc. can then be used to determine a customized corrective control action to be taken by the feedback control of the xerographic print engine to remedy or compensate for the defect(s).

Full-width array sensing of two-dimensional residual mass structure to enable mitigation of specific defects

A printing apparatus may include a heating element with at least one of a contact fuser, a radiant fuser, a substrate preheater, an image bearing member heater, and a transfuser, the heating element including a lattice of filaments wherein the filaments are separated from each other by a spacing and the spacing is such that an energy input into the heating element is radiantly output in a specific frequency band. A method of using a printing apparatus may include providing a heating element that is part of the printing device and that includes a lattice of filaments wherein the filaments are separated from each other by a spacing and the spacing is such that an energy input into the lattice is radiantly output in a specific frequency band, and performing at least one printing operation.

Printing device heating element and method of use thereof

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Webster, NY, United States of America

Christopher A Dirubio