Hewlett-packard Company

Hewlett-packard Development Company, L.P.

Robert D Haselby

Michael A Nguyen

Keith E Cobbs

Lowell J Stewart

Daniel Steven Kline

William Scott Osborne

Samuel A Stodder

Chuong C Ta

Robert A Boeller

Marvin LeRoy Patterson

Albert Prall Kendig

Jack H Schmidt

Gerold G Firl

Morad M Samii

Curtis J Behrend

Henry Flournoy

Irene H Williams

Daud Abd Al-Malik Zoss

Kevin A Merrill

Jeffrey S Best

Samuel R Haugh

George Bothwell

Narendra Penumudl

Embodiments for connecting and disconnecting a first pair of conductors of a jack from a second pair of conductors of the jack, the first pair of conductors configured to connect to a first line and the second pair of conductors configured to connect to a secondary line, detecting a voltage or a current on the secondary line while the second pair of conductors is disconnected from the first pair of conductors, and notifying a user in response to detecting the voltage or the current on the secondary line while the second pair of conductors is disconnected from the first pair of conductors are disclosed.

Determining an active line

Apparatus and techniques are disclosed for aligning the operation of the ink jet printhead cartridges of a multiple printhead ink jet swath printer that includes a print carriage that is movable along a horizontal carriage scan axis, (b) first and second ink jet printhead cartridges supported by the movable carriage for printing onto a print media that is selectively movable along a vertical media scan axis, and (c) an optical sensor supported by the movable carriage. The optical sensor includes a quad photodiode detector whose outputs are indicative of the horizontal positions of vertical test lines imaged on the detector in conjunction with horizontal alignment correction, as well as the vertical positions of horizontal test lines imaged on the detector in conjunction with vertical alignment correction

Calibration system to correct printhead misalignments

Apparatus and techniques are disclosed for aligning the operation of the ink jet printhead cartridges of a multiple printhead ink jet swath printer that includes a print carriage that is movable along a horizontal carriage scan axis, (b) first and second ink jet printhead cartridges supported by the movable carriage for printing onto a print media that is selectively movable along a vertical media scan axis, and (c) an optical sensor supported by the movable carriage. The optical sensor includes a quad photodiode detector whose outputs are indicative of the horizontal positions of vertical test lines imaged on the detector in conjunction with horizontal alignment correction, as well as the vertical positions of horizontal test lines imaged on the detector in conjunction with vertical alignment correction.

Automatic print cartridge alignment sensor system

Alignment sensor system for multiple print cartridges

Scan exposure in a row or swath scanner is controlled by pulsing light sources with pulses that are separated by dark intervals from each other--and from the detector readout periods. Detector sequencing is thereby made independent of the velocity of the pixel-line advance mechanism. Different pulse widths for different colors provide color correction without calculation, or regularize color-space conversion calculations where needed. In a swath scanner, known technology of printing modes is imported into the scanning context. Order of pixel columns within each swath is reversed for printing--permitting use of novel configurations such as a dual-parallel-flatbed copier in which a single common scan-and-advance mechanism simultaneously transports the scan sensor and printheads. To produce mirror images, this configuration is also used without column reversal. In addition to red, green and blue light sources, an infrared source is used for reading invisible indicia that identify forms or media types. The scan sensor is also used for auxiliary printing functions.

Underpulsed scanner with variable scan speed, P. W. M. color balance,

Greater throughput is possible by using wider print swaths in each traverse across printing media. Multiple print cartridges are mounted to be offset from each other in the media scan direction (X-axis). The amount of offset is adjustably varied by selective on/off control of individual printing elements as well as by relative mechanical movement of the print cartridges.

Wide-swath printer/plotter using multiple printheads

Apparatus and techniques are disclosed for aligning the operation of the ink jet printhead cartridges of a multiple printhead ink jet swath printer that includes a print carriage that is movable along a horizontal carriage scan axis, (b) first and second ink jet printhead cartridges supported by the movable carriage for printing onto a print media that is selectively movable along a vertical media scan axis, and (c) an optical sensor supported by the movable carriage.

Optical print cartridge alignment system

Signals indicating ink-discharge presence control priming and preferably halt document creation pending ink resupply--or pending an operator command to go on without resupply. A detector senses ink discharge; circuits including a programmed microprocessor apply the detector signal to control, most typically, pen priming or repriming--and preferably related functions including suspension of printer operation. The detector preferably includes an optical source and detector along an optical path that intersects an ink-discharge path. With a pen that has multiple ink-discharge nozzles, preferably the apparatus distinguishes between ink discharge from the different nozzles (by correlation with nozzle-actuating pulses), and accordingly controls priming of each nozzle independently. Preferably this system is operated before starting to print a new sheet and upon newly installing a pen. In event of inadequate ink discharge, progressively more-energetic priming impulses (higher voltage or duration, or both) are directed to the pen, until adequate discharge results or no further energy increase is deemed suitable.

Apparatus for enhancing ink-flow reliability in a thermal-inkjet pen;

Apparatus and techniques are disclosed for aligning the operation of the ink jet printhead cartridges of a multiple printhead ink jet swath printer that includes a print carriage that is movable along a horizontal carriage scan axis, (b) first and second ink jet printhead cartridges supported by the movable carriage for printing onto a print media that is selectively movable along a vertical media scan axis, and (c) an optical sensor supported by the movable carriage. Alignment of the operation of the printheads along the media scan axis is performed by determining with the optical sensor the relative positions of horizontal test line segments printed by selected nozzles of the printhead cartridges. The relative position information is utilized to calculate a vertical alignment correction which is implemented by enabling selected ink jet nozzles of the printheads and adjusting the position of one printhead cartridge relative to the other such that the nozzles of the ink jet printheads are properly spaced along the media scan axis.

Print cartridge alignment in paper axis

Apparatus and techniques are disclosed for aligning the operation of the ink jet printheads of a multiple printhead ink jet swath printer, and particularly for aligning the operation of the printheads along the carriage scan axis. The relative positions of vertical test line segments printed by the cartridges at a fixed swath position are determined with an optical sensor. The relative position information is utilized to calculate horizontal alignment corrections for the printhead cartridges which are utilized to adjust the horizontal offset shifts provided for the swath data and to adjust the timing of the firing of the ink jet nozzles of the printhead cartridges.

Print cartridge bidirectional alignment in carriage axis

Apparatus for determining inter-pen offsets in a multiple pen ink jet printer including a drop detector for measuring flight time of ink drops, an aperture plate disposed in the print media plane, and a carriage position sensor for determining carriage position when ink drop flight time exceeds a predetermined value, which indicates that an ink jet is at the edge of the aperture plate. The sensed carriage positions for the respective pens provides information indicative of inter-pen offset in the scan axis direction. In a further embodiment of the invention, the aperture plate can have a stair-shaped boundary to facilitate the calibration of a plurality of nozzles in one scan. For determination of inter-pen offset in the media scan direction, the aperture includes a comb-like boundary that is utilized to produce detect/no detect pattern for a nozzle array in each of the pens, whereby the pattern for each of the pens provides information indicative of the offset between pens.

Inter pen offset determination and compensation in multi-pen ink jet

Apparatus for determining inter-pen offsets in a multiple pen ink jet printer including a drop detector for measuring flight time of ink drops, an aperture plate disposed in the print media plane, and a carriage position sensor for determining carriage position when ink drop flight time exceeds a predetermined value, which indicates that an ink jet is at the edge of the aperture plate. The sensed carriage positions for the respective pens provides information indicative of inter-pen offset in the scan axis direction. In a further embodiment of the invention, the aperture plate can have a stair-shaped boundary to facilitate the calibration of a plurality of nozzles in one scan. For determination of inter-pen offset in the media scan direction, the aperture includes a comb-like boundary that is utilized to produce the detect/no detect pattern for a nozzle array in each of the pens, whereby the pattern for each of the pens provides information indicative of the offset between pens.

Inter pen offset determination and compensation in multi-pen thermal ink

A media advance system for swath-type printers for precisely positioning the media for successive swath printing. A dual photodiode line sensor is mounted on the print head. The diode active areas are separated by less than the line widths of lines printed in the media margin. Circuitry is provided to provide a signal indicative of the difference between the photocurrents produced by each photodiode. For the first swath of the page or plot, marginal lines are drawn by the first and Nth print device of the print head. Without moving the media, the line sensor is positioned over the marginal line printed by the first device, and the resulting difference signal is saved as a reference value. The media is then advanced until the same value of the difference signal is obtained from the line image of the marginal line drawn by the Nth print device. The media is then advanced a predetermined amount to precisely position the media for the next successive swath to be printed.

Growing community of inventors

San Diego, CA, United States of America

Robert D Haselby