Hewlett-packard Development Company, L.P.

Xerox Corporation

Conor D Kelly

Scott A Lerner

Alexander N Govyadinov

Mark Raymond Parker

Lisa Marie Schmidt

Trevor James Snyder

Ernest I Esplin

Susan June Zoltner

Brian Edward Williams

Wiatt E Kettle

Matthew David Beasley

Charles Otis

A method measures distances between two printed lines on a rotating image receiving member to identify fluid drop mass or fluid drop velocity changes in inkjet ejectors in an inkjet printing system. An initial distance between the two lines is measured at the start of the operational life of the system. During the operation of the printing system, the lines are reprinted and the distance between the two lines compared to the initial distance stored in association with the printheads that printed the lines. If the distance has changed by more than a predetermined amount, a printer parameter is adjusted.

System and method for measuring fluid drop mass with reference to test pattern image data

A method measures distances between two printed lines on a rotating image receiving member to identify fluid drop mass or fluid drop velocity changes in inkjet ejectors in an inkjet printing system. An initial distance between the two lines is measured at the start of the operational life of the system. During the line of the printing system, the lines are reprinted and the distance between the two lines compared to the initial distance. If the distance has changed by more than a predetermined amount, a firing signal for the printheads that printed the lines is adjusted.

A method of operating a printhead of an imaging device includes actuating a plurality of ink jets of the printhead to emit drops of ink onto an image receiving surface in accordance with a test pattern. The test pattern includes full pixel density areas and half pixel density areas that alternate in a process direction. Distances in a process direction between drops of the full pixel density areas and drops of the half pixel density areas in transition regions of the test pattern are then measured. The measured process direction distances are then correlated to a graininess level for the printhead.

Method for calibration

A method of operating a multi-junction photovoltaic cell with junctions connected in series includes operating each junction at a different, respective maximum power point. A photovoltaic circuit includes: at least one multi-junction photovoltaic cell, comprising at least first, second, and third terminals; a first junction of the photovoltaic cell positioned intermediate the first and second terminals; a second junction of the photovoltaic cell positioned intermediate the second and third terminals; and a device for independently setting current flow through the first junction and the second junction to allow for maximum power point operation of each junction, the device for setting current flow being connected to the second terminal.

Three-terminal two-junction photovoltaic cells and method of use

At least first and second narrowband beams of light, respectively of different wavelengths, are concurrently directed onto a modulator respectively at first and second angles of incidence.

Projectors and operation thereof

A tunable laser has a first optical element spaced apart from a second optical element to form a laser cavity of fixed length there between. An optical gain medium is in at least part of the laser cavity A third optical element is selectively spaced apart from and facing the first optical element or is selectively spaced apart from and facing the second optical element.

Tunable laser apparatus and methods

An optical relay includes a first lens, a lens module, and a second lens. The first lens is configured to receive modulated light from a first spatial light modulator. The first lens is configured to refract the modulated light into the lens module. The lens module is configured to collimate and focus the modulated light into the second lens. The second lens is configured to refract the modulated light onto a second spatial light modulator.

Optical relay

An optical relay comprising a first mirror and a second mirror is provided. The first mirror is configured to receive modulated light from a first spatial light modulator and reflect the modulated light onto the second mirror. The second mirror is configured to reflect the modulated light onto the first mirror, and the first mirror is configured to reflect the modulated light onto a second spatial light modulator.

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Albany, OR, United States of America

Conor D Kelly