JAMES DOUGLAS MARTIN
Pilots at Quesada Dr, Rochester, NY

5272493, Dec 21, 1993

Apr 2, 1992

7/862150

Fred F. Hubble - Rochester NY
Thomas J. Hammond - Penfield NY
James P. Martin - Rochester NY

Xerox Corporation - Stamford CT

G01D 1514, G01D 942, G01D 1506

346160

A precision belt hole sensor and associated conditioning circuitry provides precise trigger signals that enable synchronous printing in a color printer. An image bar recording system, which, in a preferred embodiment, utilizes a plurality of LED image bars, forms a plurality of latent images on a moving photoreceptor which may subsequently be developed in different colors. A pair of sensors associated with each printbar views illuminated pixels at the end of a printbar, through a pair of oppositely aligned photoreceptor holes. The signals detected by the sensor are amplified and processed to provide inputs to a comparitor circuit which generates an output signal at a time which precisely defines the passage of the trailing edge of the hole, past the sensors. The signal from the comparitor is used to accomplish skew registration of the printbar and to provide sync signals to enable precise formation of the leading edge of the associated image frame.

5319537, Jun 7, 1994

Dec 10, 1992

7/988587

Edward A. Powers - Penfield NY
Kenneth R. Ossman - Macedon NY
Fred F. Hubble - Rochester NY
James P. Martin - Rochester NY

Xerox Corporation - Stamford CT

H04N 121, B41J 2435

346108

A Raster Output Scanner (ROS) color printer is formed by providing several ROS imagers adjacent image exposure locations of a photoreceptor belt. Each ROS imager forms a separate color image in response to video input signals with each color image superimposed in registration over the previously formed images. Registration in the process direction is enabled by a quad cell photosensor whose output is continually compared to determine whether process registration deviations from a previously established position are necessary. Correction signals are generated in an iterative fashion until a preselected process registration position is re-established. The quad cell detector is also used for a second function; to produce the start and end of scan signals which enable image registration in the cross-process direction.

5184011, Feb 2, 1993

Jan 3, 1991

7/635837

Fred F. Hubble - Rochester NY
John M. Mitchell - Henrietta NY
James P. Martin - Rochester NY

Xerox Corporation - Stamford CT

G01D 534

25023114

The invention comprises a sensor system in a printhead scanner which is capable of achieving accurate pixel to pixel registration. A plastic film strip with alternating fiducial bars and spaces is scanned. A voltage pattern is triggered by the zero slope points of the voltage induced by a sensing mechanism being moved along the plastic film strip.

5339150, Aug 16, 1994

Mar 23, 1993

8/035830

Fred F. Hubble - Rochester NY
James P. Martin - Rochester NY
Jeffrey J. Folkins - Rochester NY

Xerox Corporation - Stamford CT

G03G 1501

355326R

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 on the photoreceptor surface, detecting the center of the lines and controlling the operation of the imager in response thereto. In one embodiment, four LED print bars form a composite color image in a single pass. A photosensor is placed beneath the print bars; a narrow target line is formed on the belt surface a few scan lines before the start of an exposure frame. The center of the line is detected by circuitry connected to the sensor output which produces a signal corresponding to detection of the center of the target line. This output signal is generated for each of the three downstream print bars and a signal is applied to each print bar to start the image exposure sequence in registration with first image exposure. In a second embodiment, skew registration adjustments are enabled by forming two line marks at opposite ends of the photoreceptor, detecting the center of each mark and making the adjustments of the position of the downstream print bars based on time differences between detection of the generation of the two signals.

5519497, May 21, 1996

Nov 25, 1994

8/345037

Fred F. Hubble - Rochester NY
Michael D. Borton - Ontario NY
James P. Martin - Rochester NY
Ralph A. Shoemaker - Rochester NY

Xerox Corporation - Stamford CT

G01N 2147, G01N 2155

356445

An infrared densitometer which measures the diffuse component of reflectivity as marking particles are progressively deposited on a moving photoconductive belt. Collimated light rays are projected onto a test patch including the marking particles. The light rays reflected from the test patch are collected and directed onto a photodiode array. The photodiode array generates electrical signals proportional to the total flux and a diffuse component of the total flux of the reflected light rays. Circuitry compares the electrical signals and determines the difference to generate an electrical signal proportional to the specular component of the total flux of the reflected light rays. Additional circuitry adds the electrical signals proportional to the total flux and the diffuse component of the total flux of the reflected light rays and compares the result of the summed signal to the specular component to provide a total diffuse signal for controlling developed mass.

5078497, Jan 7, 1992

Aug 25, 1989

7/399051

Michael D. Borton - Ontario NY
Fred F. Hubble - Rochester NY
James P. Martin - Rochester NY
Theresa K. Mattioli - Rochester NY
Ralph A. Shoemaker - Rochester NY

Xerox Corporation - Stamford CT

G01N 2147

356446

A densitometer which measures the reduction in the specular component of the reflectivity of a portion of a surface having a liquid deposited thereon. Collimated light rays, in the visible spectrum, are projected onto the portion of the surface having the liquid thereon. The light rays reflected from the portion of the surface having the liquid deposited thereon are collected and directed onto a photodiode array. The photodiode array generates electrical signals proportional to the total flux and the diffuse component of the total flux of the reflected light rays. Circuitry compares the electrical signals and determines the difference therebetween to generate an electrical signal proportional to the specular component of the total flux of the reflected light rays.

5433166, Jul 18, 1995

May 12, 1994

8/242025

David A. Donatello - Rush NY
Kenton H. Barker - Penfield NY
Ronald W. Dinger - Rochester NY
James M. Martin - Rochester NY

General Railway Signal Corporation - Rochester NY

B61L 2924, F21V 2100

116202

A light signal provides fixed focus and the ability to service the device solely from the rear. This light signal comprises a housing having a rear entry for desired maintenance and an immovable front wall, the lens mount containing a lens unit that is removable secured to an inside surface of the immovable front wall of the housing. Each lens mount includes a fixed focusing means having a receptacle for operative receipt of a light means, wherein the fixed focusing means is positioned at the end of the lens mount nearest an inner lens; whereby the focus of the light means is fixed relative to the lens unit.

5083161, Jan 21, 1992

Aug 25, 1989

7/398597

Michael D. Borton - Ontario NY
Fred F. Hubble - Rochester NY
James P. Martin - Rochester NY
Theresa K. Mattioli - Rochester NY
Ralph A. Shoemaker - Rochester NY

Xerox Corporation - Stamford CT

G03G 2100

355208

An infrared densitometer which measures the reflectivity of a selected region on a moving photoconductive belt 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. A 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.

5394223, Feb 28, 1995

Aug 17, 1992

7/930642

Steven C. Hart - Webster NY
Fred F. Hubble - Rochester NY
Thomas J. Hammond - Penfield NY
Jeffrey J. Folkins - Rochester NY
James P. Martin - Rochester NY

Xerox Corporation - Stamford CT

G03G 500

355212

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.