Xerox Corporation

John A Durbin

James D Rees

James J Appel

William L Lama

Robert P Loce

Stephen T Avery

Thomas Acquaviva

Richard F Lehman

John Richard Andrews

Howard A Mizes

Ernest I Esplin

Robert Michael Lofthus

William J Nowak

Michael John Martin

Daniel W Costanza

Yeqing Zhang

Michael E Harrigan

Aron Nacman

Stephen C Corona

David K Shogren

James Bruce Campbell

Bhaskar T Ramakrishnan

Susan June Zoltner

Edward A Powers

Richard A Spinelli

Steven Van Cleve Korol

Frederick A Green

Ross E Schroll

George Laurens Taylor

Andrew S Yeh

Joel Chan

James W Stevens

Vinod K Agarwal

Lisa Marie Schmidt

Russell J Watt

Rosario A Bracco

Ngoc-Diep Nguyen

Susan E Dunn

George R Simpson

Matthew Hudson Dixon

Kenneth Ralph Chamberlain

Richard M Bobbe

Frederick A Seedhouse

Carlos O Alva

Anne Fitzpatrick

Luo Cheng

Paul H Stiebitz

Katie Maria Teslow

Kelly D Sims

Paul H Steibitz

Warren H Woolley

A method evaluates image quality in an ink printing system and generates data values for altering the operation of the ink printing system. The method includes generating an ink image on an ink image receiving member that corresponds to a digital image stored in the ink printing system, generating a scanned image signal corresponding to the ink image, generating firing signal waveform adjustments and image data adjustments with reference to the scanned image signal corresponding to the ink image, and operating a printhead in an ink imaging system with reference to the firing signal waveform adjustments and the image data adjustments.

System and method for adjusting operation of printheads in an ink printing device

Reflex writing is a group of algorithms developed to maintain color registration in xerographic systems using multiple imagers, in which sequential color separations are written based on events in the spatial domain. The imaging system includes a raster output scanner imager for the black station and a light emitting diode bar for the color station. A simulated machine clock signal is generated based on a running average of a plurality of actual machine clock periods determined from pulses received from a photoreceptor module drive roll encoder. For each black scanline written the distance the belt travels is tracked using the simulated machine clock signal, and when the black latent image scanline has traveled the known distance between the two imagers, the light emitting diode scanline is written registered with respect to the raster output scanner scanline.

Hybrid imager printer using reflex writing to color register an image

Pre-polygon optics are provided which consist of a compact design such that the number of pre-polygon elements in the pre-polygon optics is reduced while achieving desired light beam characteristic. The pre-polygon optics may consist of a hybrid toroidal diffractive optical element, refractive cross-cylindrical optical elements, refractive spherical and cylindrical optical elements, a refractive sagittal cylindrical optical element or a refractive tangential cylindrical optical element. Accordingly, advantages such as lower cost and ease of alignment are achieved.

Double-pass sagittally offset pre-polygon optics for raster output scanners

A system for concurrently imaging the first and second sides of different sequential duplex documents in alternating image lines alternating between the first and second imaging stations. This system is shown in a system for imaging both of the first and second opposing sides of duplex documents with higher productivity, with a generally 'V' shaped low profile document sheet feeding path with first and second arms merging at a base position having a document reversing system, for sequentially feeding documents from an input tray through the first arm to the base position, and then back through the second arm to an output tray. A first imaging station is in the first arm for imaging the first sides of the documents, and a second imaging station is in the second arm for imaging the second sides. Both imaging stations have a simple, partially shared fixed elements optical system mounted entirely inside the document path, which can share a single electro-optical digital imager. The duplex documents are not inverted, yet are returned to the output tray in the same orientation as the stack in the overlying input tray. Compatible simplex document copying can also be provided.

Duplex documents scanner with alternating scan lines from dual imaging

A system for imaging both of the first and second opposing sides of duplex documents with higher productivity, with a generally 'V' shaped low profile document sheet feeding path with first and second arms merging at a base position having a document reversing system, for sequentially feeding documents from an input tray through the first arm to the base position, and then back through the second arm to an output tray. A first imaging station is in the first arm for imaging the first sides of the documents, and a second imaging station is in the second arm for imaging the second sides. Both imaging stations have a simple, partially shared fixed elements optical system mounted entirely inside the document path, which can share a single electro-optical digital imager. The duplex documents are not inverted, yet are returned to the output tray in the same orientation as the stack in the overlying input tray. Compatible simplex document copying can also be provided. Additionally disclosed is a system for concurrently imaging the first and second sides of different sequential duplex documents in alternating image lines alternating between the first and second imaging stations.

Simplified and higher productivity duplex document scanning systems

A raster output scanner is capable of creating images at a wide range of selectable resolutions. A laser source for creating an image is modulated at a pixel clock rate. A clock command value is determined as a function of a value related to the pixel clock rate and a value related to a desired resolution in the fast-scan direction and a desired resolution in the slow-scan direction of an image to be created on the photosensitive surface. The pixel clock rate is controlled in response to the clock command value. A polygon command value is determined as a function of the value related to the pixel clock rate, a value related to a desired resolution in the fast-scan direction of an image to be created on the photosensitive surface, and a value related to a rotational velocity of the polygon mirror. The rotational velocity of the polygon mirror is controlled in response to the polygon command value.

Control system for a variable-resolution raster output scanner

In an overfilled ROS polygon architecture, stray reflection from facets adjacent the completely filled (illuminated) facet are neutralized by placing an optical isolator in the path of the unwanted stray reflections. In a first embodiment, the isolator comprises a linear polarizer and a quarter wave plate. In a second embodiment, the isolator comprises a liquid crystal quarter wave plate and a cholesteric liquid crystal cell.

Suppression of stray light reflections in a raster output scanner (ROS)

A color correction method is provided for an electronic printing system that results in a color print that is made as close as possible to what an operator actually observes on a monitor screen (What you see is what you get). The printing system includes a computer, a color printer, and a color monitor. A calibration is automatically performed by the system's computer through the use of calibration software, a series of test patterns stored in the computer memory, a monitor calibrating device, and a scanner equipped with color trichromatic measurement capabilities.

Method for matching color prints to color images on a monitor screen

An image bar recording system, which, in a preferred embodiment, utilizes an LED image bar, with associated circuitry for recognizing which of individual LEDs comprising the print bar are out of registration in the slow scan, process direction of a moving photoreceptor upon which the image is to be recorded. Modification of the drive circuits to the individual LEDs results in energization signals being delayed to the identified, misregistered LEDs resulting in an exposure line which is in correct slow scan registration. According to another aspect of the invention, the delayed signals are selectively applied to intentionally cause a misregistered exposure line when using the image bar in conjunction with a raster output scan system.

Electronic adjustment of slow scan image registration in an image

A document registration guide as provided by mounting a retractable pattern bearing substrate beneath a glass document platen. The substrate operates in the manner of a window shade, presenting a plurality of document outlines which are visible to an operator during a pre-copy state. The operator can select the appropriate document outline pattern, and position the document to be exposed along the outline ensuring the required and proper registration for that document. At start of scan, the substrate is retracted out of the document exposure area and is returned to its initial position at the end of the copying cycle.

Document registration utilizing retractable transparent member beneath

In an electronic printer which utilizes an image write bar, a control circuit is provided to compensate for the effects of vibration in a rotating photoconductive member, typically a photoreceptor drum. In one embodiment an encoder is positioned so as to detect spatial displacements of indicia affixed to the photoconductor surface, Correction signals are generated and sent to control circuits which adjust the on/off timing of the write bar operation and/or the intensity of the image bar output. This adjustment results in compensation for the effects of photoconductor vibration.

Image bar printer compensated for vibration-generated scan line errors

A gradient index lens array having improved stray light characteristics is enabled by coating the surfaces of the fibers comprising the array with a low transmittance, low viscosity material. The index of this material is matched to that of the fiber surface to prevent Fresnel reflection. The interstitial areas of the lens array comprises a light absorbing material. In another embodiment, stray light caused by light scattering at the end faces of the lens array is reduced by masking the end face with a mask having apertures overlying the fiber faces. The mask apertures have slightly smaller diameters to mask out the rough outer edge of the fibers.

Gradient index lens array with improved image quality due to stray light

An illumination housing includes a glass platen for supporting a document, the platen having at least one surface area uniformly roughened. In one embodiment, both surfaces are uniformly roughened by an etching process. The surface of the platen are thus rendered diffusely reflective to specular hot or cold light spots formed by light reflected from optical components within the illumination system and compensates for platen-derived specular reflections into the projection lens.

Illumination system utilizing a document platen with a diffusely

A display device incorporates an optical demagnifying component adjacent the display surface. The optical component forms a demagnified real or virtual image of the display formed at the display viewing surface, effectively increasing the view angle of an observer.

Display device with increased view angle

A short focal length lens array has a plurality of lenslets formed within the body of a photosensitive glass. The lenslets have areas which are oriented such that they tilt away from each other from the center out to the array edges. The lens array acts as a reduction or enlargement lens when reproducing objects at an object plane onto an image plane. A one or two row embodiment is disclosed suitable for incremental scanning of a document at image planes. A further full frame lens array is disclosed for providing full frame exposure of a document at various selected magnifications.

Short focal lens array with multi-magnification properties

Growing community of inventors

Webster, NY, United States of America

John A Durbin