Hewlett-packard Development Company, L.p.

Hewlett-packard Company

Hewlett-packard Corporation

Steven P Downing

Jeffrey C Madsen

Robert M Yraceburu

Wade A Powell

Stuart Douglas Spencer

Steve Orrin Rasmussen

Le Gia Pham

Vance M Stephens

Angela S Chen

Jason S Belbey

Wesley Baxter Roche

Steven H Walker

Steven B Elgee

Bruce G Johnson

Elliott Downing

Steve A O'Hara

Christopher M Lesniak

Richard Lee Brinkly

Teressa L Roth

Edward L Feldhousen

Sierra Lynn Triebe

Kevin Bensel

Brian Mar

In one example in accordance with the present disclosure an object transportation device is described. The device includes a continuous belt having an inner surface and an outer surface. The inner surface interacts with a belt transport system. The device also includes a number of attachment devices disposed on the outer surface of the belt. An object attaches to the belt via an attachment device. An attachment device includes two angled protrusions extending from the outer surface from a common joint.

Object transportation with V-shaped attachment devices

A wiping assembly includes a pair of guide elements located at opposite ends of a headland region of a fluid ejection assembly to extend in a second orientation generally perpendicular to a first orientation through which the opposite ends extend. Each guide element includes at least one first portion and a second portion. The at least one first portion selectively receives biased releasable engagement from a non-wiping portion of a wiping element extending along the first orientation to cause a wiping portion of the wiping element to be in generally parallel relation to, and spaced apart from, the headland region. The second portion causes the non-wiping portion to no longer be in biased releasable engagement against the guide element and causes the wiping portion to be biased in wiping relation against the headland region.

Guide for a wiping assembly

A bearing mount of a rotatable printer drum having a rotational axis includes a main drum bearing, rotationally supporting the drum and having an outer bearing race, and at least two secondary roller bearings, angularly spaced from each other. The secondary roller bearings are positioned to rollably support the outer bearing race and allow lateral translation of the main bearing.

Printer drum bearing mount

A printing system includes a printhead, a movable transport surface opposite the printhead and configured to transport a print medium relative to the printhead, and a cleaning medium in contact with the transport surface while at least one of the cleaning medium and the transport surface are moved relative to one another.

Cleaning medium for ink-jet hard copy apparatus

Techniques for high accuracy media positioning in a swath printer. A high accuracy media positioning method includes mounting a computer-controlled printing element for movement along a swath axis for swath printing of an image on a print medium, moving the printing element along the swath axis and printing at least a portion of a swath of the image on the print medium, sensing the position of an edge of the just printed portion of the image which is nominally aligned with the scan axis; providing relative motion between the print medium and the printing element to accurately position the printing element in dependence on the sensed position of the edge of the just printed portion of the image. The fine compensation needed to compensate positioning errors can be performed prior to printing a swath, or even 'on the fly' during the printing of a swath. Coarse positioning errors can be measured by the sensor and compensated by use of the printer media advance system, by increasing or decreasing as appropriate the nominal commanded swath-to-swath advance distance.

High accuracy swath advance paper positioning for printers

In an inkjet printing apparatus an inkjet printhead has a plurality of inkjet nozzles which eject ink onto media located within a print-zone. A drive shaft is located upstream of the printhead and is incrementally rotated to advance the media. The drive shaft has a longitudinal axis, a first radius over a central length and a second radius less than the first radius at a first recess and a second recess, each said recess being peripheral to the central length. A plurality of pinch devices stabilize the media against the drive shaft. A first guide is aligned with the first recess and is spaced from an axis of the drive shaft by a first distance which is less than the first radius. A second guide is aligned with the second recess and is spaced from the axis by a second distance less than the first radius.

Controlling media curl in print-zone

A method and mechanism for cleaning a paper transport belt of undesirable ink deposits caused by ink-jet aerosol and printing overshoot operations uses a special cleaning medium. An absorbent material is positioned in the print zone of a hard copy apparatus to scrub the belt. An ink solvent is used to rehydrate dried ink. The scrubber can be in the form of consumable sheets or a continuous roll form.

In an inkjet printing apparatus an inkjet printhead ejects ink into a print-zone. A drive shaft, located upstream of the printhead, has a longitudinal axis, a first radius over a central length, and a second radius less than the first radius at a first recess and a second recess. Each recess is peripheral to the central length. A plurality of pinch devices stabilize the media against the drive shaft. A first guide and a second guide, spaced from the longitudinal axis, are aligned with and extend into the first recess and second recess.

A belt tracking system for an endless belt having left and right opposed edges, the belt driven in a first direction by a belt drive system. The tracking system includes a set of periodic belt indicia formed on the belt along one or more axes aligned with the first direction. A sensor system tracks movement of the belt in a lateral direction transverse to the first direction and senses the set of belt indicia to provide sensor system signals. An actuator system effects movement of the belt in the lateral direction, the actuator system responsive to the sensor system signals for nominally maintaining a position of the belt relative to the transverse direction. A controller is responsive to the sensor system signals for detecting that the belt has tracked outside an allowable belt movement range and taking protective actions to prevent the belt from damage due to undesired lateral tracking movement. A belt indicia sensor can optionally be employed to calibrate a belt drive system.

Techniques for robust endless belt tracking control

A vacuum holddown has a holddown member with an outer surface for temporarily capturing a flexible sheet material via a vacuum force distributed across the outer surface through discrete vacuum channels. A vacuum force valving mechanism abuts an inner surface of the holddown member in a selectable sliding engagement. The valving mechanism has a pattern of apertures therethrough in predetermined pattern such that discrete valve mechanism positions produce discrete vacuum force patterns at the outer surface of the holddown member.

Sliding valve vacuum holddown method and apparatus

An encoding system is described for a media handling system including an endless belt. The encoding system includes encoding indicia associated with the endless belt. A first encoder transducer is responsive to the encoding indicia to provide a first encoder signal. A second encoder transducer is responsive to the encoding indicia to provide a second encoder signal, the second encoder transducer spatially separated from the first encoder transducer. An encoder processor is responsive to the first encoder signal and the second encoder signal to determine position data regarding the endless belt. Interruption of indicia due to a belt seam is accommodated by transferring belt position calculation from one transducer to the other as the seam passes between the two transducers. The processor is adapted to compensate for variations in the encoder indicia pitch caused by belt temperature differentials.

Belt media drive for printer with dual belt encoders

Sliding valve vacuum holddown method apparatus

The present invention addresses the problem of paper cockle by stretching the paper as it progresses along the paper path through the wet colorant printing station of a hard copy apparatus. The hard copy apparatus uses a paper feed belt system as a paper platen in which the belt or set of belts is splayed along the paper path. Firmly adhering a sheet of print media to the belt, or belts, system, such as by use of a vacuum force, as it travels through the apparatus printing zone, stretches the media orthogonally and particularly in an orientation perpendicular to the paper path.

Method and apparatus for cockle reduction in print media

A vacuum holddown has a holddown member with an outer surface for temporarily capturing a flexible sheet material via a vacuum force distributed across the outer surface through discrete vacuum channels. A vacuum force valve mechanism abuts an inner surface of the holddown member in a selectable sliding engagement. The valve mechanism has a pattern of apertures therethrough in predetermined pattern such that discrete valve mechanism positions produce discrete vacuum force patterns at the outer surface of the holddown member.

Sliding valve vacuum holddown

A method of calibrating a media advance mechanism in a printer utilizes an optical sensor of the printer to detect printed marks on a calibration sheet. The marks on the calibration sheet are spaced at actual longitudinal intervals. The calibration sheet is advanced longitudinally past the printhead carriage, and the calibration marks are detected with the optical sensor. The printer determines the apparent or measured longitudinal intervals and compares them to the actual intervals to determine errors in positioning the calibration sheet.

Growing community of inventors

Camas, WA, United States of America

Steven P Downing