Patents by Inventor Gerald M. Fletcher
Gerald M. Fletcher has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 9327526Abstract: Embodiments described herein are directed to a system for reducing electrostatic fields underneath print heads in a direct marking printing system. The system includes: one or more print heads for depositing ink onto a media substrate; a media transport for moving the media substrate along a media path past the one or more print heads; a conductive platen contacting the media transport belt; an electrostatic field reducer that includes an alternating current charge device positioned upstream of the one or more print heads; and one or apertures with electrically isolated biased electrodes separated by an opening that is in registration with the ink deposition areas of the one or more print heads. The media transport includes a media transport belt and, when the media is on the transport belt it has an electrostatic field, which can cause printing defects. The electrostatic field reducer and electrodes reduce the electrostatic field on the surface of the media and thereby reduce printing defects.Type: GrantFiled: June 7, 2013Date of Patent: May 3, 2016Assignee: Xerox CorporationInventors: Gerald M. Fletcher, Johannes N. M. de Jong, Peter Knausdorf, Steven R. Moore, Ramesh S. Palghat
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Patent number: 9211736Abstract: Embodiments described herein are directed to a system for reducing electrostatic fields underneath print heads in a direct marking printing system. The system includes: one or more print heads for depositing ink onto a media substrate; a media transport for moving the media substrate along a media path past the one or more print heads; a conductive platen contacting the media transport belt; and an electrostatic field reducer that includes an alternating current corona device positioned upstream of the one or more print heads. The media transport includes a media transport belt and, when the media substrate is on the transport belt it has an electrostatic field, which can cause printing defects. The electrostatic field reducer reduces the electrostatic field on the surface of the media substrate and thereby reduces printing defects.Type: GrantFiled: July 25, 2012Date of Patent: December 15, 2015Assignee: Xerox CorporationInventors: Gerald M. Fletcher, Joannes N. M. de Jong, Peter Knausdorf, Steven R. Moore, Palghat S. Ramesh
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Patent number: 9132673Abstract: A semi-conductive media transport is used with an ink jet printing system. A belt is held flat and slides across a conductive platen, causing electrostatic charges on the belt. The belt is made semi-conductive to prevent charge buildup. The belt has an effective surface resistivity between a lower limit to preclude a buildup of electrostatic charges, and an upper limit to enable electrostatic tacking of the media to the belt. The resistivity limits vary depending upon belt velocity, thickness, material, belt and media dielectric constant, and slot width. A pair of charged nip rollers tacks the media substrate to the belt. An AC corotron is disposed above the belt to establish a net neutral charge state on the media substrate and the belt. Platen slots directly below the ink jet print heads will maintain the net neutral charge state on the media substrate and the belt.Type: GrantFiled: December 27, 2012Date of Patent: September 15, 2015Assignee: Xerox CorporationInventors: Gerald M. Fletcher, Palghat S. Ramesh, Peter J. Knausdorf, Joannes N.M. de Jong
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Patent number: 8998403Abstract: When tacking print media to a print media transport belt in a printer, a tack module having a pair of nips is employed to control charge migration in across the print media in order to tolerate lead edge curl while ensuring uniform printing. An upstream nip is formed by a first bias transfer roll and a first backup roll, and a downstream nip is formed by a second bias transfer roll and a second backup roll. The respective backup rolls are offset slightly upstream of the respective bias transfer rolls. Charge of opposite polarities is applied to the first backup roll and the second bias transfer roll to facilitate taking of the print media to the print media transport belt.Type: GrantFiled: November 6, 2012Date of Patent: April 7, 2015Assignee: Xerox CorporationInventors: Gerald M. Fletcher, Joannes N. M. de Jong, Peter J. Knausdorf
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Patent number: 8947482Abstract: Embodiments described herein are directed to a system for reducing electrostatic fields underneath print heads in a direct marking printing system. The system includes: one or more print heads for depositing ink onto a media substrate; a media transport for moving the media substrate along a media path past the one or more print heads; a conductive platen contacting the media transport belt; an electrostatic field reducer that includes an alternating current charge device positioned upstream of the one or more print heads; and one or electrically isolated biased electrodes in registration with the ink deposition areas of the one or more print heads. The media transport includes a media transport belt and, when the media is on the transport belt it has an electrostatic field, which can cause printing defects. The electrostatic field reducer and electrodes reduce the electrostatic field on the surface of the media and thereby reduce printing defects.Type: GrantFiled: March 15, 2013Date of Patent: February 3, 2015Assignee: Xerox CorporationInventors: Palghat S. Ramesh, Joannes N. M. de Jong, Gerald M. Fletcher
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Publication number: 20140267501Abstract: Embodiments described herein are directed to a system for reducing electrostatic fields underneath print heads in a direct marking printing system. The system includes: one or more print heads for depositing ink onto a media substrate; a media transport for moving the media substrate along a media path past the one or more print heads; a conductive platen contacting the media transport belt; an electrostatic field reducer that includes an alternating current charge device positioned upstream of the one or more print heads; and one or electrically isolated biased electrodes in registration with the ink deposition areas of the one or more print heads. The media transport includes a media transport belt and, when the media is on the transport belt it has an electrostatic field, which can cause printing defects. The electrostatic field reducer and electrodes reduce the electrostatic field on the surface of the media and thereby reduce printing defects.Type: ApplicationFiled: March 15, 2013Publication date: September 18, 2014Applicant: XEROX CORPORATIONInventors: Palghat S. Ramesh, Joannes N. M. de Jong, Gerald M. Fletcher
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Publication number: 20140184712Abstract: A semi-conductive media transport is used with an ink jet printing system. A belt is held flat and slides across a conductive platen, causing electrostatic charges on the belt. The belt is made semi-conductive to prevent charge buildup. The belt has an effective surface resistivity between a lower limit to preclude a buildup of electrostatic charges, and an upper limit to enable electrostatic tacking of the media to the belt. The resistivity limits vary depending upon belt velocity, thickness, material, belt and media dielectric constant, and slot width. A pair of charged nip rollers tacks the media substrate to the belt. An AC corotron is disposed above the belt to establish a net neutral charge state on the media substrate and the belt. Platen slots directly below the ink jet print heads will maintain the net neutral charge state on the media substrate and the belt.Type: ApplicationFiled: December 27, 2012Publication date: July 3, 2014Applicant: XEROX CORPORATIONInventors: Gerald M. Fletcher, Palghat S. Ramesh, Peter J. Knausdorf, Joannes N.M. de Jong
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Publication number: 20140125748Abstract: When tacking print media to a print media transport belt in a printer, a tack module having a pair of nips is employed to control charge migration in across the print media in order to tolerate lead edge curl while ensuring uniform printing. An upstream nip is formed by a first bias transfer roll and a first backup roll, and a downstream nip is formed by a second bias transfer roll and a second backup roll. The respective backup rolls are offset slightly upstream of the respective bias transfer rolls. Charge of opposite polarities is applied to the first backup roll and the second bias transfer roll to facilitate taking of the print media to the print media transport belt.Type: ApplicationFiled: November 6, 2012Publication date: May 8, 2014Applicant: Xerox CorporationInventors: Gerald M. Fletcher, Joannes N. M. de Jong, Peter J. Knausdorf
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Publication number: 20140028750Abstract: Embodiments described herein are directed to a system for reducing electrostatic fields underneath print heads in a direct marking printing system. The system includes: one or more print heads for depositing ink onto a media substrate; a media transport for moving the media substrate along a media path past the one or more print heads; a conductive platen contacting the media transport belt; an electrostatic field reducer that includes an alternating current charge device positioned upstream of the one or more print heads; and one or apertures with electrically isolated biased electrodes separated by an opening that is in registration with the ink deposition areas of the one or more print heads. The media transport includes a media transport belt and, when the media is on the transport belt it has an electrostatic field, which can cause printing defects. The electrostatic field reducer and electrodes reduce the electrostatic field on the surface of the media and thereby reduce printing defects.Type: ApplicationFiled: June 7, 2013Publication date: January 30, 2014Inventors: Gerald M. Fletcher, Johannes N. M. de Jong, Peter Knausdorf, Steven R. Moore, Ramesh S. Palghat
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Publication number: 20140028769Abstract: Embodiments described herein are directed to a system for reducing electrostatic fields underneath print heads in a direct marking printing system. The system includes: one or more print heads for depositing ink onto a media substrate; a media transport for moving the media substrate along a media path past the one or more print heads; a conductive platen contacting the media transport belt; and an electrostatic field reducer that includes an alternating current corona device positioned upstream of the one or more print heads. The media transport includes a media transport belt and, when the media substrate is on the transport belt it has an electrostatic field, which can cause printing defects. The electrostatic field reducer reduces the electrostatic field on the surface of the media substrate and thereby reduces printing defects.Type: ApplicationFiled: July 25, 2012Publication date: January 30, 2014Applicant: XEROX CORPORATIONInventors: Gerald M. Fletcher, Joannes N.M. de Jong, Peter Knausdorf, Steven R. Moore, Palghat S. Ramesh
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Patent number: 7957656Abstract: A toner image transfer assembly has a tacking assembly, an image transfer assembly, and a media transport assembly. The tacking assembly senses critical properties of media while electrostatically tacking media to a transport device. The tacking assembly forwards data corresponding to the sensed electrical properties to the image transfer assembly so that the image transfer assembly anticipates the electrical properties of an approaching media type.Type: GrantFiled: December 5, 2008Date of Patent: June 7, 2011Assignee: Xerox CorporationInventors: Steven R. Moore, Paul J. DeGruchy, Peter J. Knausdorf, Gerald M. Fletcher
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Publication number: 20100142982Abstract: A toner image transfer assembly has a tacking assembly, an image transfer assembly, and a media transport assembly. The tacking assembly senses critical properties of media while electrostatically tacking media to a transport device. The tacking assembly forwards data corresponding to the sensed electrical properties to the image transfer assembly so that the image transfer assembly anticipates the electrical properties of an approaching media type.Type: ApplicationFiled: December 5, 2008Publication date: June 10, 2010Applicant: XEROX CORPORATIONInventors: Steven R. MOORE, Paul J. DEGRUCHY, Peter J. KNAUSDORF, Gerald M. FLETCHER
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Patent number: 7403728Abstract: System and methods may calibrate an AC rms voltage applied to a coronode of a charging device to achieve a predefined operating current at a target value of DC shield voltage. The target value of DC shield voltage may be set to be substantially below an over-voltage condition. System and methods may use a calibration routine that may determine a minimum AC voltage required to achieve the target value of DC shield voltage. Systems and methods may alternatively, or additionally, sense current and adjust the applied voltage to obtain a target current.Type: GrantFiled: July 13, 2005Date of Patent: July 22, 2008Assignee: Xerox CorporationInventors: Gerald M. Fletcher, John F. O'Brien, Bruce J. Parks, Eliud Robles-Flores, Alfred James Claflin, Jerry Floyd Adams
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Patent number: 7389077Abstract: The magnitude and polarity of the voltage on the fuser roll surface is controlled by either electronic charge application means or by applying charge control agents to the fuser. For negative toner, the fuser roll voltage must also be negative (and visa versa). This will repel the negative toner at the entrance to the fuser nip, prevent the toner from transferring to the fuser roll at the entrance of the fuser nip and preclude the formation of NVO and consequently prevent MOC.Type: GrantFiled: December 21, 2005Date of Patent: June 17, 2008Assignee: Xerox CorporationInventors: John S. Berkes, Gerald M. Fletcher, Brendan Kunzmann
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Patent number: 7379695Abstract: Provided herein is a system for using a cleaning web in an electrostatic printing process to provide a uniform and thin wax layer on the fuser roll and thereby minimize print history effects, reduce triboelectric voltages on the fuser roll and provide uniform and improved release of the toner from the fuser roll. The application of this beneficial thin film to the fuser roll is accomplished by impregnating the cleaning web with a wax material that is substantially the same as the wax material in the toner used in the system. This impregnated wax, therefore, has the same release and triboelectric properties as the wax in the toner and therefore will not attract residual toner but will rather repel it.Type: GrantFiled: December 21, 2005Date of Patent: May 27, 2008Assignee: Xerox CorporationInventors: John S. Berkes, Gerald M. Fletcher, Brendan Kunzmann
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Patent number: 7336920Abstract: A printing system includes first and second marking devices for applying images to print media. A primary fusing device is associated with each of the first and second marking devices for applying a primary fusing treatment to the images applied to print media by the first and second marking devices. A secondary fusing module receives printed media from the first and second marking devices, the secondary fusing module including first and second secondary fusing devices which selectively apply a further fusing treatment to the images applied to the printed media.Type: GrantFiled: September 27, 2005Date of Patent: February 26, 2008Assignee: Xerox CorporationInventors: David G. Anderson, Steven R. Moore, Gerald M. Fletcher, Bryan J. Roof, Eric S. Hamby, Robert M. Lofthus
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Patent number: 7324779Abstract: A printing system includes first and second marking devices for applying images to print media. A first primary fusing device is associated with the first marking device for applying a primary fusing treatment to the images applied to print media by the first marking device. A second primary fusing device is associated with the second marking device for applying a primary fusing treatment to the images applied to print media by the second marking device. At least one secondary fusing device receives printed media from the first and second marking devices. The secondary fusing device selectively applies a further fusing treatment to at least a portion of the images applied to the printed media to increase a uniformity of an appearance characteristic between printed images generated by the first marking device and the second marking device.Type: GrantFiled: September 27, 2005Date of Patent: January 29, 2008Assignee: Xerox CorporationInventors: David G. Anderson, Steven R. Moore, Gerald M. Fletcher, Bryan J. Roof, Eric S. Hamby, Robert M. Lofthus
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Patent number: 7313337Abstract: Disclosed is a method and apparatus for sensing residual toner mass after transfer of a xerographic image, to facilitate the identification and characterization of different types of transfer defects. The technique employed utilizes a nominal residual mass signature, measured at the start of a job, in conjunction with subsequent residual mass signature, where the calculated difference between the nominal and subsequent signatures is used to indicate transfer defects and changes in transfer efficiency.Type: GrantFiled: October 13, 2005Date of Patent: December 25, 2007Assignee: Xerox CorporationInventors: Aaron M. Burry, Gerald M. Fletcher, Eric S. Hamby, Peter Paul
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Patent number: 7310493Abstract: A glossing subsystem is provided that receives duplexed output media that has been selectively marked on a first side and a second side. The glossing subsystem includes: a first glossing unit that selectively provides a first gloss level to a first side of the duplexed output media; and, a second glossing unit that selectively provides a second gloss level to a second side of the duplexed output media.Type: GrantFiled: June 24, 2005Date of Patent: December 18, 2007Assignee: Xerox CorporationInventors: Bryan J. Roof, Gerald M. Fletcher
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Patent number: 7244485Abstract: A seamed flexible belt having a substrate and a seam having interlocking seam members, wherein the interlocking seam members are held together by an adhesive having polyamide and an optional electrically conductive filler, for use in electrostatographic, contact electrostatic, digital and other like printing machines.Type: GrantFiled: April 11, 2001Date of Patent: July 17, 2007Assignee: Xerox CorporationInventors: Ralph A. Mosher, T. Edwin Freeman, Theodore Lovallo, Damodar M. Pai, John F. Yanus, Timothy J. Fuller, Markus R. Silvestri, Gerald M. Fletcher, Antonio DeCrescentis, Ihor W. Tarnawskyj