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公开(公告)号：GB2165045A
公开(公告)日：1986-04-03
申请号：GB8523844
申请日：1985-09-27
Applicant: XEROX CORP
Inventor： HUBBLE III FRED F , BULLOCK RANDOLPH A , CHEUNG LI-FUNG , CRUMRINE ROBERT E , MARTIN JAMES P , WHITE PETER P , ZOMORRODI MEHRDAD
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公开(公告)号：DE69412318T2
公开(公告)日：1999-01-21
申请号：DE69412318
申请日：1994-03-18
Applicant: XEROX CORP
Inventor： HUBBLE FRED F III , FOLKINS JEFFREY J , MARTIN JAMES P
Abstract: An apparatus and method of adjusting an imager in an electrophotographic printing machine to correct for registration errors when forming a composite image. Registration errors are sensed by forming one or more target lines (30) on the photoreceptor (17) surface, detecting the centre of the lines and controlling the operation of the imager in response thereto. In one embodiment, four LED print bars (10A,12A,14A,16A) form a composite color image in a single pass. A photosensor (40,42,44) is placed beneath the print bars; a narrow target line (30) is formed on the belt surface a few scan lines before the start (23) of an exposure frame. The centre of the line is detected by circuitry (Figs 4,5) connected to the photosensor output which produces a signal (Fig. 10) corresponding to detection of the centre of the target line (30). This output signal is generated for each of the three downstream print bars (12A,14A,16A) and a signal is applied to each print bar to start the image exposure sequence in registration with first image exposure (I1). In a second embodiment (Fig.6), skew registration adjustments are enabled by forming two line marks (30;30') at opposite ends of the photoreceptor (17), detecting the centre of each mark and making the adjustments of the position of the downstream print bars (12A,14A,16A) based on time differences between detection of the centre of the two marks.
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公开(公告)号：DE69311649T2
公开(公告)日：1997-12-18
申请号：DE69311649
申请日：1993-08-18
Applicant: XEROX CORP
Inventor： HUBBLE III FRED F , MARTIN JAMES P , POWERS EDWARD A , OSSMAN KENNETH R
Abstract: An apparatus and method for reliably monitoring the position of a radiant energy beam, for example, a scanning laser beam (6) such as that produced by a raster output scanning system (4) to expose a photoresponsive member (14), where the beam traverses the surface of a photoreceptive member at a high rate of speed. The apparatus, which includes a lateral-effect photodiode (44A or 44B), is also capable of signaling when the radiant energy beam traverses a specific location. The apparatus may also be used to determine the relative intensity of the radiant energy beam, thereby significantly reducing the space and expense necessary to monitor the radiant energy beam by combining multiple sensing operation in a single apparatus.
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公开(公告)号：CA1240754A
公开(公告)日：1988-08-16
申请号：CA491274
申请日：1985-09-20
Applicant: XEROX CORP
Inventor： HUBBLE FRED F III , BULLOCK RANDOLPH A , CHEUNG LI-FUNG , CRUMRINE ROBERT E , MARTIN JAMES P , WHITE PETER P , ZOMORRODI MEHRDAD
Abstract: The present invention is concerned with a self-adjusting document sensor compensating for degradation of the sensor system. A suitable light source and a detector are provided, the output of the detector being fed into an amplifier whose gain depends upon a feedback signal. Periodically, the output of the amplifier is compared to a reference. If the output of the amplifier falls below the reference, a pulse is sent to a ripple counter whose digital output is fed back to the amplifier to change the gain of the amplifier.If the detector is an unbiased photodiode operating in the transconductance mode, the leakage currents and their subsequent effect on output with amplifier gain changes will be minimized.
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公开(公告)号：DE69311649D1
公开(公告)日：1997-07-24
申请号：DE69311649
申请日：1993-08-18
Applicant: XEROX CORP
Inventor： HUBBLE III FRED F , MARTIN JAMES P , POWERS EDWARD A , OSSMAN KENNETH R
Abstract: An apparatus and method for reliably monitoring the position of a radiant energy beam, for example, a scanning laser beam (6) such as that produced by a raster output scanning system (4) to expose a photoresponsive member (14), where the beam traverses the surface of a photoreceptive member at a high rate of speed. The apparatus, which includes a lateral-effect photodiode (44A or 44B), is also capable of signaling when the radiant energy beam traverses a specific location. The apparatus may also be used to determine the relative intensity of the radiant energy beam, thereby significantly reducing the space and expense necessary to monitor the radiant energy beam by combining multiple sensing operation in a single apparatus.
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Patent Agency Ranking
公开(公告)号：BR9504390A
公开(公告)日：1997-05-27
申请号：BR9504390
申请日：1995-10-11
Applicant: XEROX CORP
Inventor： ANDERSON DAVID G , CLAFIN ALFRED J , HUBBLE FRED F III , MARTIN JAMES P
Abstract: A maintenance system for an ink jet printer of the type having a full width array printhead has a movable carriage with a droplet sensor and a nozzle recovery device. As the carriage moves along the length of the printhead, each nozzle checked, one at a time, by the droplet sensor for the presence or absence of an ejected droplet and if the droplet has the correct directionality. Any problem nozzle is identified during a single traversal of the carriage across the printhead, and during a second traversal, the identified problem nozzles have a recovery operation performed on them such as being cleaned to remove any dried ink or other contaminating particles or being primed in the case of a clogged nozzle. The problem nozzles which have had a recovery operation performed on them and checked again by the droplet sensor is required for the entire array of nozzles, and ink is conserved since only predetermined nozzles are printed.
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公开(公告)号：CA2089218A1
公开(公告)日：1994-02-18
申请号：CA2089218
申请日：1993-04-07
Applicant: XEROX CORP
Inventor： HART STEVEN C , HUBBLE FRED F III , HAMMOND THOMAS J , FOLKINS JEFFREY J , MARTIN JAMES P
IPC: B41J2/51 , B41J2/385 , B41J2/46 , G03G15/01 , G03G15/36 , G03G21/14 , G03G15/04 , G03G13/04 , G03G15/00
Abstract: An apparatus for positional tracking a moving photoconductive belt and adjusting an imager in an electrophotographic printing machine to correct for alignment errors when forming a composite image. Registration errors are sensed by developing an appropriate set of target marks, detecting the target marks, and controlling the position of the imager.
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公开(公告)号：DE69311649T3
公开(公告)日：2001-08-09
申请号：DE69311649
申请日：1993-08-18
Applicant: XEROX CORP
Inventor： HUBBLE III FRED F , MARTIN JAMES P , POWERS EDWARD A , OSSMAN KENNETH R
Abstract: An apparatus and method for reliably monitoring the position of a radiant energy beam, for example, a scanning laser beam (6) such as that produced by a raster output scanning system (4) to expose a photoresponsive member (14), where the beam traverses the surface of a photoreceptive member at a high rate of speed. The apparatus, which includes a lateral-effect photodiode (44A or 44B), is also capable of signaling when the radiant energy beam traverses a specific location. The apparatus may also be used to determine the relative intensity of the radiant energy beam, thereby significantly reducing the space and expense necessary to monitor the radiant energy beam by combining multiple sensing operation in a single apparatus.
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公开(公告)号：DE69412318D1
公开(公告)日：1998-09-17
申请号：DE69412318
申请日：1994-03-18
Applicant: XEROX CORP
Inventor： HUBBLE FRED F III , FOLKINS JEFFREY J , MARTIN JAMES P
Abstract: An apparatus and method of adjusting an imager in an electrophotographic printing machine to correct for registration errors when forming a composite image. Registration errors are sensed by forming one or more target lines (30) on the photoreceptor (17) surface, detecting the centre of the lines and controlling the operation of the imager in response thereto. In one embodiment, four LED print bars (10A,12A,14A,16A) form a composite color image in a single pass. A photosensor (40,42,44) is placed beneath the print bars; a narrow target line (30) is formed on the belt surface a few scan lines before the start (23) of an exposure frame. The centre of the line is detected by circuitry (Figs 4,5) connected to the photosensor output which produces a signal (Fig. 10) corresponding to detection of the centre of the target line (30). This output signal is generated for each of the three downstream print bars (12A,14A,16A) and a signal is applied to each print bar to start the image exposure sequence in registration with first image exposure (I1). In a second embodiment (Fig.6), skew registration adjustments are enabled by forming two line marks (30;30') at opposite ends of the photoreceptor (17), detecting the centre of each mark and making the adjustments of the position of the downstream print bars (12A,14A,16A) based on time differences between detection of the centre of the two marks.
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公开(公告)号：DE69026774T2
公开(公告)日：1996-11-07
申请号：DE69026774
申请日：1990-08-21
Applicant: XEROX CORP
Inventor： BORTON MICHAEL D , HUBBLE FRED F III , MARTIN JAMES P , MATTIOLI THERESA K , SHOEMAKER RALPH A
Abstract: An infrared densitometer which measures the reflectivity of a selected region on a moving photoconductive belt (10) covered at least partially with marking particles. Collimated light rays are projected onto the selected region of the moving photoconductive member with or without marking particles thereon. The light rays reflected from the selected region of the moving photoconductive member are collected and directed onto a photodiode array (106). The photodiode array generates electrical signals proportional to the diffuse component of the total reflectivity of the selected region of the photoconductive member with and without marking particles thereon. Circuitry determines a control signal as a function of the difference in electrical signals.
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