Hewlett-packard Development Company, L.P.

Hewlett-packard Indigo B.v.

Indigo N.v.

Craig Breen

Michael Plotkin

Haim Livne

Doron Shaked

Gideon Amir

Mani Fischer

David K Towner

Peter Gysling

Dale Haddon Wolin

Dror Kella

Boaz Tagansky

Eyal Shelef

Shlomo Harush

Rodolfo Jodra

Gregory Braverman

Sharon Nagler

Gidi Amir

Martin Chauvin

Shai Druckman

Haggai Abbo

Ami Shiff

Maya Shalev

Dani Sagi

Omry Flum

Yuri Baril

Avner Arnstein

Barak Markus

Gidl Amir

Dan Pritsker

Itzhak Malobani

Haim Livine

An anamorphic optical element and an adjustment mechanism for selectively rotating the optical element either around an axis substantially in a vertical direction, an axis substantially in an optical axis direction, an axis substantially in a plane formed by the vertical direction and the optical axis direction, or combination of axes thereof is used to vary a vertical separation between two or more spots.

Method and apparatus for controlling multiple beam spacing

Detecting an issue in a digital printer that has an optical element positioned to direct a laser beam towards a photoconductor surface may include sending optical element position commands to move the optical element to compensate for inconsistent movements of a photoconductor drum and creating a record of the optical element position commands.

Issue detection in a digital printer

A method for designing a screen includes receiving screen information related to a picture element divided into a number of subunits of the picture element, and determining an amount of an ink to apply to a media at a location of the picture element in response to the information. The subunits of the picture element have a higher resolution than the resolution of a printing apparatus at which the printing element will be reproduced.

Pixel exposure as a function of subpixels

An image processing method () for converting an original image () into a final, pixelated image () suitable for printing on a printer arranged to print two-tone images and capable of printing partial area exposed pixels, comprises antialiasing () the original image () into an intermediate pixelated image () comprising greyscale pixels having assigned greyscale values. The method comprises the further-step, of translating () the intermediate image () into the final, pixelated image () by translating the assigned greyscale values into partial exposure values indicative of the amount of desired pixel area for a corresponding pixel or pixels in the final image.

Image processing method and apparatus

Electrophotographic print system, comprising a photosensitive medium, and a laser array being provided with a plurality of laser diodes arranged to emit light onto the photosensitive medium for varying an electrical potential on a surface of the photosensitive medium, and a plurality of heat dissipation diodes, each heat dissipation diode being arranged in proximity to a corresponding laser diode, wherein each laser diode and the corresponding heat dissipation diode are coupled to a common drive circuit and are arranged in opposite current flow directions with respect to each other, so that in use the current flows either through the laser diode or through the heat dissipation diode depending on the current flow direction in the drive circuit.

Laser array

A correction method for correcting unintended spatial variation in lightness across a physical image produced by a xerographic process, the method comprising producing a test image using the xerographic process, measuring a difference between actual lightness and intended lightness across at least part of the test image, and varying the light source level used subsequently in the xerographic process to correct for the measured unintended difference.

Correction method, apparatus, data carrier or system for correcting for unintended spatial variation in lightness across a physical image produced by a xerographic process

First delay mechanisms to delay a beam-detect signal by different lengths of time in synchronization with a first clock signal. The beam-detect signal is generated responsive to one or more beams being output towards a rotating polygonal mirror having facets and directed towards a sensor. One or more second delay mechanisms each correspond to one of the beams to delay a second clock signal, resulting in a beam-clock signal to align the beam over successive reflections by the facets. A mechanism determines a delay by which each second delay mechanism is to delay the second clock signal, based on the beam-detect signal as differently delayed by the first delay mechanisms.

Aligning beams over successive reflections by facets of rotating polygonal mirror

A method for detecting and correcting misregistration between a plurality of separations printed by a printing apparatus, comprising: producing a calibration print output on a substrate, the calibration print output including at least one calibration pattern, wherein the at least one calibration pattern translates horizontal misregistration into a detectable indicator of misregistration in a process direction; detecting misregistration; and, performing a fine adjustment of the horizontal position of at least one of the separations using the at least one calibration pattern.

Horizontal color plane registration correction

An imager comprising a photosensitive surface; a light source which produces at least one scanning light beam; a deflector, arranged to deflect the at least one scanning light beam onto the photosensitive surface; and a sensor which measures the orientation of the deflector. The imager also comprises a controller operative to determine a placement error of said at least one scanning beam on the photosensitive surface, responsive to the orientation measurement by the sensor: and an actuator, responsive to the displacement error, and arranged to change the direction of deflection of the at least one light beam by the deflector. The sensor is configured to measure the orientation of the deflector substantially at a null in a vibrational mode of the deflector.

High performance dynamic mirror

Skew compensation apparatus for compensating for skew of a multi-beam scanning source, comprises: delay commencement detector(s) for detecting the start of a beam scanner position, position detectors for detecting the position of the multiple beams at a predefined interval following the commencement, so that the position indicates skew of the respective beam, and compensating electronics for automatically inserting a compensation for the skew by altering a delay into a timing signal for switching the respective beam. The commencement detector can be an existing start of scan detector and the apparatus can be built into the writing head, particularly at the conjugate location to the focal plane or at the focal plane of a laser printer or the like to provide a self-calibrating printer.

Skewing compensation method and apparatus in a laser based image-forming system

High duty cycle scanner for laser printer

Growing community of inventors

Rehovot, Israel

Craig Breen