Hewlett-packard Development Company, L.p.

Michael Nordlund

Manish Agarwal

Cherng Linn Teo

Seng San Koh

Xiaoxi Huang

Aiqiang Yang

Sing-Yan Wan

Rhea Patricia Liem

Ban-Ho Chong

In a method for compensating for media linefeed errors in a media feed apparatus, a first correction parameter is applied during a first length of a media feed operation and a second correction parameter, which differs from the first correction parameter, is applied during a second length of the media feed operation.

Media linefeed error compensation method

An apparatus for adjusting a spacing between a printhead and a print medium in a printer is provided. The printhead is mounted in a carriage which is slidable along a guiding rod. The apparatus includes a first and second assembly for adjusting a position of a first and second portion of the carriage, respectively. The second assembly includes a camshaft attached to and slidable with respect to the carriage, one or more cams attached to the camshaft, and a bushing member. A first surface of the bushing member abuts a predefined profile of the cam, and a second surface of the bushing member abuts the guiding rod. The sliding of the camshaft with respect to the carriage causes a distance between the bushing member and the camshaft to vary according to the predefined profile of the cam. Accordingly, the spacing between the printhead and the print medium is adjusted.

Apparatus for adjusting a spacing between a printhead and a print medium in a printer

An apparatus for use in printing to a rotational media having a surface to be printed to and being rotatable about an axis extending away from the surface is provided. The apparatus includes an engaging arrangement to engage the rotational media so as to impart controlled rotational movement thereto about the axis. The engaging arrangement is configured to be coupled to printer gearing on a printer, such that rotation of the printer gearing on the printer causes rotation of the rotational media when engaged on the engaging arrangement.

Method and apparatus for rotational media printing

In a method for independently wiping a first and a second printhead of an inkjet printing mechanism, a first and a second wiping assembly separated from each other are provided in the printing mechanism. Furthermore, the wiping of the first printhead by the first wiper and the wiping of the second printhead by the second wiper are separately controlled.

Independent wiping of printhead

A method for measuring a pen-to-paper spacing in an inkjet printing mechanism is provided. Firstly, a first nozzle of a printhead in the printing mechanism ejects a first ink drop onto a medium at a first ejection velocity when the printhead moves at a first moving velocity along a scanning axis and when the printhead reaches a first position along the scanning axis. Subsequently, a second nozzle of the printhead ejects a second ink drop onto the medium at a second ejection velocity when the printhead moves at a second moving velocity along the scanning axis and when the printhead reaches a second position along the scanning axis. The spacing between the two nozzles along the scanning axis and the spacing between the two positions along the scanning axis are predetermined. Then the spacing between the first and second ink drops on the medium along the scanning axis is measured. The pen-to-paper spacing can be determined from the first and second moving velocities, the first and second ejection velocities, the spacing between the first and second nozzles along the scanning axis, the spacing between the first and second positions along the scanning axis and the spacing between the first and second ink drops on the medium along the scanning axis.

Measuring pen-to-paper spacing

A method for servicing a printhead of an inkjet printing mechanism is provided. Firstly, a plurality of time difference information is collected by the printing mechanism. Each time difference information represents a period of time passed between end of a last print job and receipt of a succeeding print job. The print jobs are sent from a computer connected to the printing mechanism. Subsequently, the printing mechanism uses the plurality of time difference information to determine a nominal time information representing an amount of time. After the determination of the nominal time information, the printing mechanism periodically performs a first level servicing dependent upon the nominal time information.

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Singapore, Singapore

Michael Nordlund