Abstract: A printer uses closed loop control to keep material drops ejected by a printhead within a predetermined range. The printer forms at least two objects on a support member and then operates a specular sensor array to obtain image data of the two objects on the support member. The two objects have different predetermined heights to enable a controller in the printer to identify the mass or volume of the material drops forming the objects to adjust operational parameters of the printer to maintain the mass or volume of the material drops in the predetermined range.

Abstract: An inkjet printer is configured to apply a coating material to an imaging surface before an ink image is formed on the surface. At least one optical sensor generates image data of the coating on the imaging surface and identifies a thickness of the coating material. Components of the coating material applicator can be adjusted to keep the thickness of the coating material within a predetermined range.

Abstract: A method for operating an inkjet printer to identify inoperable inkjets includes ejecting ink drops of a first color onto an image receiving surface to impose a control pattern on a document zone in addition to an ink image generated in the document zone. A density of the control pattern in the document zone changes at a rate that is at or less than a predetermined threshold. The method includes generating scanned image data of a portion of the control pattern on the image receiving surface and identifying a performance parameter corresponding to inkjets and printheads in the printer.

Abstract: A system and method for optimizing video-based tracking of an object of interest are provided. A video of a regularized motion environment that comprise multiple video frames is acquired and an initial instance of an object of interest in one of the frames is then detected. An expected size and orientation of the object of interest as a function of the location of the object is then determined. The location of the object of interest is then determined in a next subsequent frame using the expected size and orientation of the object of interest.

Abstract: A method for operating an inkjet printer includes forming a printed mark with a plurality of inkjets in a printhead, generating scanned image data of the printed mark, and modifying an image data correction parameter and firing signal waveform parameter for one of the inkjets to correct a process direction registration error between the locations of ink drops from the one inkjet and the location of the printed mark. The image data correction parameter modifies the location of ink drops from the one inkjet by an integer number of pixels and the firing signal waveform parameter modifies the location of ink drops from the one inkjet by a fractional pixel to enable registration of the inkjet.

Abstract: A system and method for adjusting a transport path length of a continuous web of recording media in a printing system printing duplex images. The method includes detecting alignment marks, for instance top of form (TOF) marks, on the continuous web of print media and adjusting the path length to provide substantially accurate registration of first and second images on opposite sides of the web for duplex imaging. The system to adjust path length includes idler rollers movable with respect to turnbar rollers.

Abstract: In an inkjet printer, a first printhead forms a first mark on a print medium using a high-contrast ink. A second printhead forms a second mark on the first mark using a low-contrast ink. The printer generates image data of the low-contrast ink mark and the high-contrast ink, and a controller in the printer identifies a cross-process direction offset between the first printhead and the second printhead with reference to a distance between the center of the first mark and the second mark in the image data.

Abstract: A method of operating a printer includes identifying a halftone level a first ink drop parameter corresponding to a contone level in image data for using a contone to halftone mapping. The method includes operating printheads to form a printed pattern using the first ink drop parameter and identifying a reflectance level of the printed pattern in scanned image data. The method includes modifying the halftone level in the mapping if the identified reflectance level is outside of a tolerance range from a normalized reflectance value associated with the contone level and storing the modified halftone level in a memory for printing the contone level.

Abstract: A method of operating a printer to detect errors in an optical sensor includes forming a printed line across a first side of a print medium and generating first image data corresponding to the printed line with the optical sensor. The optical sensor generates second image data of the second side of the print medium as the print medium passes the optical sensor a second time. A detect in the optical sensor is identified with reference to a difference between process direction alignments of the line in the first image data and the second image data.

Abstract: An inkjet printer is configured to capture image data of a bare rotating imaging surface and use the image data of the bare rotating imaging surface to remove noise from subsequent images of printed ink on the rotating imaging surface. A controller in the printer is configured to measure cross-correlations between margins in the bare rotating imaging surface image data and margins in the subsequent images of printed ink to identify areas of alignment between the image data of the bare rotating imaging surface and the subsequent images of printed ink. The data in the areas in the image data of the bare rotating imaging surface that are aligned with areas in the subsequent images are used to remove the background noise produced by structure in the rotating imaging surface.

Abstract: A method of operating a printer includes identifying a region of a print medium located between marks formed by a first plurality of inkjets in the printer and an edge of the print medium. The printer activates a second plurality of inkjets to print ink drops into the region during a printing operation. The method enables full-bleed or near full-bleed printing for different media sizes.

Abstract: A method for process direction registration in an inkjet printer includes ejecting ink drops from a first inkjet at less than a maximum operating rate onto an image receiving surface moving in a process direction. The method includes generating image data samples of the image receiving surface including the ink drops. The method further includes identifying a center of the ink drops in the process direction with reference to the image data samples and storing a time offset value in a memory to correct an identified process direction offset between the identified center of the ink drops and another identified center of ink drops that are ejected by another inkjet.

Abstract: An aqueous inkjet printer is configured to evaluate and adjust multiple components within the printer with reference to image data of the surface of a rotating member obtained at different times during a single print cycle. The print cycle can be performed in a multiple pass manner to enable a single optical sensor to be used for generation of the image data. Alternatively, the print cycle can be performed in a single revolution of the rotating member and multiple optical sensors positioned about the rotating member to generate the image data.

Abstract: A method for process direction registration in an inkjet printer includes ejecting ink drops from a first inkjet at less than a maximum operating rate onto an image receiving surface moving in a process direction. The method includes generating image data samples of the image receiving surface including the ink drops. The method further includes identifying a center of the ink drops in the process direction with reference to the image data samples and storing a time offset value in a memory to correct an identified process direction offset between the identified center of the ink drops and another identified center of ink drops that are ejected by another inkjet.

Abstract: A method for printing on a continuous print medium having a plurality of pages includes identifying a location of a feature in image data that are generated from a portion of a first page in the print medium. The method includes modifying a time of operation of a marking unit to form an image on each page in the plurality of pages at a predetermined distance from the edge of each page with reference to the location of the identified feature in the image data. In one configuration, the method enables precise placement of printed images over preprinted forms.

Abstract: An inkjet printer is configured to apply a coating material to an imaging surface before an ink image is formed on the surface. At least one optical sensor generates image data of the coating on the imaging surface and identifies a thickness of the coating material. Components of the coating material applicator can be adjusted to keep the thickness of the coating material within a predetermined range.

Abstract: An aqueous inkjet printer is configured to evaluate and adjust multiple components within the printer with reference to image data of the surface of a rotating member obtained at different times during a single print cycle. The print cycle can be performed in a multiple pass manner to enable a single optical sensor to be used for generation of the image data. Alternatively, the print cycle can be performed in a single revolution of the rotating member and multiple optical sensors positioned about the rotating member to generate the image data.

Abstract: An inkjet printer is configured to capture image data of a bare rotating imaging surface and use the image data of the bare rotating imaging surface to remove noise from subsequent images of printed ink on the rotating imaging surface. A controller in the printer is configured to measure cross-correlations between margins in the bare rotating imaging surface image data and margins in the subsequent images of printed ink to identify areas of alignment between the image data of the bare rotating imaging surface and the subsequent images of printed ink. The data in the areas in the image data of the bare rotating imaging surface that are aligned with areas in the subsequent images are used to remove the background noise produced by structure in the rotating imaging surface.

Abstract: A method for printing on a continuous print medium having a plurality of pages includes identifying a location of a feature in image data that are generated from a portion of a first page in the print medium. The method includes modifying a time of operation of a marking unit to form an image on each page in the plurality of pages at a predetermined distance from the edge of each page with reference to the location of the identified feature in the image data. In one configuration, the method enables precise placement of printed images over preprinted forms.

Abstract: A method of operating a printer includes identifying a region of a print medium located between marks formed by a first plurality of inkjets in the printer and an edge of the print medium. The printer activates a second plurality of inkjets to print ink drops into the region during a printing operation. The method enables full-bleed or near full-bleed printing for different media sizes.