Abstract: In a method for detecting an encoder material reading error, at least one of a sensor and an encoder material is slewed with respect to each other. Markers on the encoder material are detected with the sensor as at least one of the sensor and the encoder material is slewed with respect to each other to obtain position vs. time data of the sensor with respect to the encoder material. The position vs. time data is analyzed to determine whether a speed at which at least one of the sensor and the encoder material travels with respect to each other fell below a predetermined threshold. In addition, a determination that an encoder material reading error has occurred is made in response to a determination that the speed fell below the predetermined threshold.

Abstract: 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.

Abstract: 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.

Abstract: A method for 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 method includes dividing the image into a plurality of sectors; converting the pixel locations of at least one of the plurality of sectors of the image into polar coordinates; rotating the polar coordinates for each converted sector by predetermined respective angles; and reconverting the pixel locations of each converted sector into rasterized rectangular coordinates according to the rectangular coordinate system.

Abstract: 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.

Abstract: A dual-speed printer drive mechanism is disclosed. The drive mechanism includes a drive motor, a drive roller for feeding a media sheet toward and through a printing area and a drive transmission for coupling the drive roller to the drive motor for turning the drive roller with different gear reduction ratios. The drive mechanism further includes a gear reduction ratio selector disposed in the drive transmission for selectively turning the drive roller at a first gear reduction ratio for feeding the media sheet to the printing area, and for selectively turning the drive roller at a second gear reduction ratio for feeding the media sheet with precision for image printing while in the printing area.

Abstract: 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.

Abstract: 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.

Abstract: A method is provided for print quality control. To carry out this method, a printing apparatus with optical detection capability is used. This apparatus includes: advance mechanism for advancing a print medium through a print zone; a carriage assembly having at least one pen for ejecting ink droplets onto the print medium in the print zone; an optical detection unit positioned in the print zone; and a printer controller. The optical detection unit includes an image acquisition module for capturing at least one image of the print zone within a field of view (FOV) and an image processor for performing a pixel array analysis of the captured image. The image analysis is triggered by the printer controller and the result of the analysis is fed back to the printer controller for controlling the printing operation.

Abstract: 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.

Abstract: A dual-speed printer drive mechanism is disclosed. The drive mechanism includes a drive motor, a drive roller for feeding a media sheet toward and through a printing area and a drive transmission for coupling the drive roller to the drive motor for turning the drive roller with different gear reduction ratios. The drive mechanism further includes a gear reduction ratio selector disposed in the drive transmission for selectively turning the drive roller at a first gear reduction ratio for feeding the media sheet to the printing area, and for selectively turning the drive roller at a second gear reduction ratio for feeding the media sheet with precision for image printing while in the printing area.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.