Xerox Corporation

Lexmark International, Inc.

Other

Mark Andrew Omelchenko

Daniel W Costanza

Robert Michael Lofthus

Michael Robert Furst

John Parker Richey

Michael John Martin

Gregory Lawrence Ream

David Anthony Schneider

Joseph M Wing

Olga Y Ramirez

Michael F Leo

James M Casella

Mark A Adiletta

Stacy Marie Pargett

Orlando J Lacayo

Stanley John Wallace

John Patrick Spicer

Paul Douglas Horrall

Harald Portig

David Mark Kerxhalli

Brian Robert Conrow

David Keneth Ahl

Cary Patterson Ravitz

Franklin Joseph Palumbo

Daniel Paul Cahill

Danny Keith Chapman

Richard C Schenk

Ssujan Hou

Robert Leonard Burdick

John Lemaster

Delbert Lester Elliott

David W Covert

Philip David Jones

Thad Carlton Switzer

Matthew Lowell McKay

Kurt Matthew Korfhage

Ronald E Shaul

Adrian J Lee

Patricia J Weber

David Kerxhali

Kisha H Salters

Saundra L Haque

Frederick A Scacchitti

Richard M Boothe

Ssujan (James) Hou

Lou Bressler

John Sirianni

Adam Daniel Cahill

A method and system for carrying out an image-to-paper printer registration setup includes: using a printer undergoing registration setup, printing a test pattern on a sheet having reference targets within a printable region of the sheet; using a scanner, scanning the printed sheet to generate an image bitmap of the test pattern-bearing sheet larger than the sheet itself so that the image bitmap contains the sheet edges and measuring in numbers of pixels the distances between the reference targets and/or sheet edges using multiple swaths of the image bitmap itself as the measuring tool; and, using a processor and based on the measured distances, calculating error-associated adjustment values in millimeters to use to correct errors in the registration setup of the image-to-paper in the printer and transferring the error-associated adjustment values to the printer to perform adjustment of its setup actuators.

Method, system and test sheet image bitmap for carrying out a scanner-and-processor based image-to-paper registration setup

A characterization procedure for the a detector in a toner patch sensor of an electrophotographic image forming device is performed with the toner patch sensor operatively connected to the image forming device's power supply. During the characterization procedure, a gain setting is determined that produces a predetermined target output from the toner patch sensor based on electromagnetic radiation reflected from a reference reflectivity sample. Subsequently, a toner patch is generated by the image forming device and a reflectance of the toner patch is measured based on the gain setting, with the toner patch sensor operatively connected to the power supply. The measurement(s) may then be used to adjust at least one electrophotographic image forming parameter. More than one reference reflectivity sample may be used, with corresponding gain settings stored in the image forming device.

Characterization of toner patch sensor in an image forming device

A method for compensating misalignment errors associated with a laser beam in an electrophotographic (EP) device is disclosed. A first value and a second value of a time-of-flight of the laser beam are determined. The second value of the time-of-flight is associated with a current value of SOS time and EOS time of the laser beam. The second value of the time-of-flight of the laser beam is compared with the first value of the time-of-flight. A duty cycle of a fuser of the EP device is monitored. An average value of the duty cycle of the fuser for a predetermined time period is determined. One or more alignment conditions of the laser beam are adjusted based on at least one of the comparisons of the second value and the first value of the time-of-flight of the laser beam, and the determined average value of the duty cycle of the fuser.

Method for compensating misalignment errors in electrophotographic device

Methods and devices for operating a toner patch sensor in an electrophotographic image forming device. A characterization procedure for a light detector in the toner patch sensor may use one or multiple reflectance standards. A gain setting is determined that produces a predetermined target output from the toner patch sensing circuit for each of the standards. The characterization procedure may be carried out at a test bench or with the toner patch sensor installed in the corresponding device.

Characterization of toner patch sensor

A method of compensating for mechanical and magnification errors affecting toner density control in an image forming device is described herein. The method includes directing light towards a toner test surface, sensing the resulting reflections, and buffering the density data corresponding to the sensed reflections during a predetermined test window. The method may compensate for mechanical and magnification errors associated with the toner test pattern by processing the buffered density data to adjust the location of the data collection windows corresponding to the toner test patterns. For example, the buffered density data may be processed to detect first and second boundary patterns disposed on the toner test surface within the test window, determine a time differential between the first and second boundary patterns, and adjust the location of the data collection windows based on the determined time differential and a nominal expected time differential.

Method to improve data collection accuracy by improved windowing in a toner density control system

Drive train motor speed is varied in a manner that compensates for characteristic rotational velocity errors of the associated drive train, such as by modulating a drive train motor speed control signal at a modulation phase and amplitude derived from the characterized rotational velocity error. Characterization can be performed on a test system for each drive train of interest, and the compensation values thus obtained can be saved for later use by systems in which the characterized drive trains are used. Thus, a drive train used in a consumables cartridge for an electrophotographic printing (EP) system can be characterized and the corresponding data saved via a label or memory circuit that is affixed to the cartridge. Such data can be used by the EP system in which the cartridge is installed to more accurately control the velocity of the image forming process members driven by the cartridge's characterized drive train.

Method and apparatus for characterizing and compensating drive train rotational velocity errors

An image processing apparatus including tandem print engines is provided for forming an image on an image receiving substrata. The apparatus includes a first print engine and a second print engine downstream from the first print engine. The second print engine is slaved to the first print engine. The first print engine has a first photoreceptor and a first period of revolution. The second print engine has a second photoreceptor and a second period of revolution. The image processing apparatus further includes an intermediate inverter that inverts the image receiving substrate between the first print engine and the second print engine. The inverter determines a phase difference between a first seam signal from the first photoreceptor and a second seam signal from the second photoreceptor.

Systems and methods for reducing image registration errors

A photoconductive member for use in a single pass multi-color printing machine is disclosed. The photoconductive member is composed of an inter seam zone having a physical seam. The inter seam zone includes one of a plurality of image-on-image registration marks respective to a particular color latent image formed on the photoconductive member in a single pass. A plurality of interdocument zones is also included on the photoconductive member wherein process control marks are formed. While the inter seam zone is used for monitoring color-to-color registration, the process control marks are monitored to adjust the timing of the printing machine so that copy media synchronizes with an asynchronous placement of the images on the photoconductive member. A single pass, multi-color electrophotographic printing machine architecture uses a vertically oriented photoconductive belt. Transfer of the toner powder images occur at the lowermost portion of the photoconductive belt. The photoconductive belt is elliptically shaped, having a major and a minor axis. N image recording stations are positioned adjacent an exterior surface of the photoconductive belt on one side of the major axis thereof. N&minus;1 image recording stations are positioned adjacent the exterior surface of the photoconductive belt on the other side of the major axis thereof. The image recording stations record electrostatic latent images on the photoconductive belt. This architecture optimizes image registration while minimizing the overall height of the printing machine.

Photoconductive member for asynchronous timing of a printing machine

A single-pass color electrophotographic printer includes four imaging stations, yellow, cyan, magenta, and black, on a generally linear path. A toned image in each toner color is developed on an image bearing member or photoconductive drum. A plurality of electrically biased first transfer rollers associated with each imaging station is operative to transfer the developed images from the photoconductive drum to an intermediate transfer member (ITM) belt that travels sequentially past the imaging stations along the generally linear path in a first transfer operation. The image on the ITM belt is transferred to media at a second transfer operation at which the ITM belt passes through a nip between a backup roller and a further electrically biased transfer roller. A servo operation is used to set the voltages on the transfer rollers. Rollers at the second transfer are positioned to direct media downwardly out of the nip to a media transport belt and to a fuser assembly. A reverse roller is provided downstream of the second transfer operation to shift the path of the ITM belt away from the media guide plate and media transport belt. The ITM belt is formed of a resistive material having a uniform thickness and high tensile modulus.

Intermediate transfer member belt/roller configuration for single-pass color electrophotographic printer

Transfer belt subassembly for a color printer includes a transfer belt, home position indicator, temperature sensor, and memory. The transfer belt subassembly is measured and characterized after fabrication, before being installed in a printer. Measurement and calibration data for the transfer belt is stored in memory as part of the subassembly, including data representing velocity characteristics of the transfer belt and temperature compensation factors used by an engine-controller in a method to govern the speed of the drive motor. When the transfer belt subassembly is inserted into a printer, the engine-controller is operative in response to data stored in the memory and sensed belt velocity and temperature data, providing adjustment of belt velocity and compensation for variations in the transfer belt speed. Using the predetermined characterizing data, precise alignment of the color planes with respect to one another is achieved for accurate color printing.

Method and apparatus for controlling transfer belt velocity of a color printer

A method of printing with an electrophotographic machine includes providing a first optical sensor for sensing a start-of-scan position of a laser beam produced by a scanning laser printhead and transmitting a first position signal indicative thereof A second optical sensor senses an end-of-scan position of the laser beam produced by the scanning laser printhead and transmits a second position signal indicative thereof A temperature of the scanning laser printhead is measured with a temperature sensing device. A plurality of positions of each of the first optical sensor and the second optical sensor are empirically determined at each of a plurality of values of the temperature of the scanning laser beam printhead. The modulation or position of the laser beam produced by the scanning laser printhead is adjusted based upon the first position signal, the second position signal, the measured temperature of the laser printhead, and the empirically determined positions of the first optical sensor and the second optical sensor and the second optical sensor. A single optical sensor and a single thermal sensor constitute the minimum hardware embodiment to perform print line position correction based upon stored empirical relationship.

Method of laser printhead registration control in an electrophotographic machine

Color imaging methods and systems are provided where each color separation image is to be registered in a composite manner under a variety of machine conditions. Registration sensors are provided to register the color separations under a variety of machine conditions while accounting for the different types of registration sensors used. A controller calibrates the registration sensors automatically based on set-up data and, using the calibrated sensors, controls the output of the image data for one or more of the color separation images to reduce or eliminate image registration offsets. The registration sensors are calibrated by directly measuring set-up marks during set-up. Each registration sensor outputs a feedback to the controller during set-up to account for phenomenon caused by variation in toner concentration or sensor susceptibility. The registration sensors provide a plurality of set-up sensor feedback values, one for each of at least four colors and one for a bare photoreceptor belt. The controller determines the differences between the set-up sensor feedback value for each of the four colors and the set-up feedback value for the bare photoreceptor belt and uses the determined differences to adjust the operating conditions for each sensor, including the amount of driving current applied to the sensor.

Image color registration sensor calibration

An improved intermediate belt system (ITM module) is provided, which controls the lateral motion of the belt in the scan direction of an EP printer, without the use of edge reinforcements or other attachments added to the belt. The tracking system of this ITM module is passive, and maintains roll alignment/parallelism within a predetermined tolerance while also maintaining roll conicity-end flare to a predetermined maximum diametral variation over the roll to minimize the effect of external forces on the belt walk rate. The ITM module also provides angled tracking guides near the tension roll to control the lateral position of the belt; the position of these tracking guides is adjustable at time of manufacture to achieve the desired lateral belt position.

Method and apparatus for reducing lateral motion of a transfer belt of a laser printer

A belt drive module and a corresponding method includes or employs a belt that moves along a path, at least one support roller or other structure that supports the belt as it moves along the path, a drive roller that effects movement of the belt along the path, a tension roller that applies a tension force to the belt in order to maintain engagement of the belt with the drive and/or support rollers, at least one processing station (e.g., an image processing station) disposed along the path that performs a process relative to a predetermined position of the belt, and a torque assist drive that applies a torque assist force Td at a location between the drive roller and the tension roller. Torque assist may be provided by a current limited DC motor or by a constant torque friction clutch applied to a roller, e.g., a stripper roller of an electrophotographic imaging system. Advantageously, the torque assist force Td facilitates accurate positioning of the belt (e.g., latent image registrations in a color imaging process employing multiple imaging processing stations) by reducing slippage between the drive roller and the belt that may be encountered due to belt wear, toner contamination and/or other debris.

Torque assist method and apparatus for reducing photoreceptor belt slippage in a printing machine

In color printing with a color registration system for the registration of plural color images on an image bearing surface, such as a photoreceptor belt of a color printer, registration marks are imaged on the image bearing surface, which registration marks correspond to the color images and are sensed by a registration marks sensor. In an initial gross registration mode the system first automatically images first registration marks, in the form of expanded chevron targets, which are greatly expanded in the process direction so as to avoid overlapping marks even if there is initial gross misregistration, to thus provide wider initial misregistration latitude for the sensor. When an acceptable initial registration is achieved, the system automatically switches to imaging more closely spaced and more frequent second registration marks, preferably regular chevron targets, providing higher registration accuracy. These registration targets may be generated along opposite sides of the image areas, on opposite sides of the photoreceptor or other image bearing surface in the process direction.

Color printing process direction color registration system with expanded chevrons

Growing community of inventors

Lexington, KY, United States of America

Mark Andrew Omelchenko