Abstract: A printhead in a digital printing includes an array of light sources for exposing a photosensitive medium moving past the printhead. Artifacts are reduced in a high-speed print mode by defining first and a second power level control values that differ by at least 20%. The light sources used to print odd-numbered image pixels are activated responsive to the first power level control value and the light sources used to print even-numbered image pixels are activated responsive to the second power level control value.

Abstract: In an embodiment, a device includes: a sensor die having a first surface and a second surface opposite the first surface, the sensor die having an input/output region and a first sensing region at the first surface; an encapsulant at least laterally encapsulating the sensor die; a conductive via extending through the encapsulant; and a front-side redistribution structure on the first surface of the sensor die, the front-side redistribution structure being connected to the conductive via and the sensor die, the front-side redistribution structure covering the input/output region of the sensor die, the front-side redistribution structure having a first opening exposing the first sensing region of the sensor die.

Abstract: A digital printing system incorporating in-track position corrections includes one or more printing subsystems, a data processing system; and a digital memory for storing a representation of an in-track position correction function, wherein the in-track position correction function is a non-linear function that specifies in-track position corrections to be applied as a function of cross-track position, and wherein the representation of the in-track position correction function includes the cross-track positions and transition direction of transitions in the in-track position correction function.

Abstract: A digital printing system incorporating in-track position corrections includes one or more printing subsystems, a data processing system; and a digital memory for storing a representation of an in-track position correction function, wherein the in-track position correction function is a non-linear function that specifies in-track position corrections to be applied as a function of cross-track position, and wherein the representation of the in-track position correction function includes the cross-track positions and transition direction of transitions in the in-track position correction function.

Abstract: A method for reducing artifacts in an electrophotographic printing system includes receiving a print job including image data for a set of pages. The electrophotographic printing system is used to print a block of pages from the print job to provide corresponding printed pages. The image data for the block of pages is analyzed to determine an average toner usage rate. If the determined average toner usage rate for the block of pages falls outside an acceptable toner usage rate range, image data for a compensation image and a number of compensation images are determined such that the average toner usage rate will be brought back into the acceptable toner usage rate range.

Abstract: A method for reducing image burn-in artifacts in an electrophotographic printing system, includes receiving a print job including image data for a set of pages to be printed. The pages are analyzed to determine that the image data for a sequence of pages in the print job are similar. The similar pages are printed using a pattern of lateral translations wherein the image data is laterally translated such that it is printed at a different lateral position on the printed page. The similar pages can also be printed using a pattern of page orientations including a first page orientation and a second page orientation, wherein the image data for the second page orientation is rotated 180 degrees relative to the image data for the first page orientation.

Abstract: An electrophotographic printing system for printing with a set of toners including a white toner. A plurality of printing modules are configured to print respective toner patterns, each including a toner image printed onto a receiver medium being transported on a transparent transport web and a corresponding registration mark positioned outside a border of the receiver medium. A registration mark sensing system is positioned to detect the printed registration marks. The registration mark sensing system includes a light detector positioned to detect light that is emitted by a light source, transmitted through the transport web and reflected off a non-white colored reflector plate positioned behind the transport web. The colored reflector plate has a color that provides detection signals for the registration marks having a magnitude that is greater than or equal to a predefined threshold.

Abstract: A method for reproducing an out-of-gamut spot color includes determining a color gamut for a color printer, and specifying a spot color by color coordinates in a three-dimensional color space. A first target color is determined corresponding to a color having a minimum color difference to the specified spot color, and a second target color is determined corresponding to a color on the color gamut surface having a hue value equal to a hue value of the specified spot color. A path is defined on the color gamut surface connecting the first target color and the second target color, wherein a control parameter is used to specify a relative position along the defined path. A user interface is provided enabling a user to adjust the control parameter to specify an aim color.

Abstract: A method for correcting in-track position errors in a digital printing system includes determining a non-linear in-track position correction function responsive to measured in-track position errors, wherein the in-track position corrections are quantized to integer in-track position corrections. A representation of the in-track position correction function is stored in a digital memory, wherein the representation of the in-track position correction function includes the cross-track positions and transition direction of transitions in the in-track position correction function. Digital image data for a digital image to be printed is received, and corrected image lines are determined by resampling the digital image data responsive to the stored representation of the in-track position correction function. The corrected image lines are modified to provide anti-aliasing pixels at cross-track positions adjacent to transitions in the in-track position correction function.

Abstract: A printing system includes a media transport system configured to pick a sheet of media from a media supply and transport it along a media transport path to a printing module. An image capture system positioned along the media transport path, includes an image capture device positioned to capture a digital image of the sheet of media, and a platen positioned behind the sheet of media, wherein a surface of the platen includes a non-uniform density pattern, and wherein the captured digital image includes at least one edge of the sheet of media and a portion of the platen that extends beyond the edge of the sheet of media. An image analysis system automatically analyzes the captured digital image to detect an edge position of the sheet of media by detecting a platen region that includes the non-uniform density pattern and a media region.

Abstract: A hierarchical printhead design supports multiple print modes. A first print mode uses a first subset of light sources having a first spacing. A second print mode uses a second subset of light sources having a second spacing which is less than the first spacing. Image data for lines of image data are sequentially loaded into the printhead, wherein if the specified print mode is the first print mode, image data for a first group of light sources corresponding to the first subset are loaded, and if the specified print mode is the second print mode, image data for the first group of light sources are first loaded, and then image data for a second group of light sources corresponding to the light sources in the second subset that are not in the first subset are loaded.

Abstract: A printing system for printing on tabbed media having a plurality of tab positions. A media transport system picks the next sheet of tabbed media from a media tray. A detection system detects the tab position for the sheet of tabbed media. The detected tab position is compared to an expected tab position and if the detected tab position is different from the expected tab position then either the front end is used to supply image data to be printed on the sheet of tabbed media having the detected tab position, or the media transport system is controlled to direct the sheet of tabbed media into a waste receptacle and pick one or more additional sheets of tabbed media until the detected tab position is the same as the expected tab position.

Abstract: A method for reproducing an out-of-gamut spot color includes determining a color gamut for a color printer, and specifying a spot color by color coordinates in a three-dimensional color space. A first target color is determined corresponding to a color having a minimum color difference to the specified spot color, and a second target color is determined corresponding to a color on the color gamut surface having a hue value equal to a hue value of the specified spot color. A path is defined on the color gamut surface connecting the first target color and the second target color, wherein a control parameter is used to specify a relative position along the defined path. A control parameter prediction function is provided which computes a predicted control parameter value as a function of color coordinates. The predicted control parameter value is used to determine an aim color for reproducing the spot color.

Abstract: A media transport system is used to transport a media sheet along a media transport path past an image capture system. The image capture system includes an image capture device positioned to capture an image of the media sheet, and a platen positioned behind the media sheet, wherein a surface of the platen includes a non-uniform density pattern. The image capture system captures an image of the media sheet that includes at least one edge of the media sheet and a portion of the platen that extends beyond the edge of the media sheet. An image analysis system automatically analyzes the captured digital image to detect an edge position of the media sheet by detecting a platen region that includes the non-uniform density pattern and a media region. The detected edge position is used to adjust a position that a printing module prints image data onto the media sheet.

Abstract: A hierarchical printhead system supports multiple print modes. A first print mode uses a first subset of light sources having a first spacing. A second print mode uses a second subset of light sources having a second spacing which is less than the first spacing. Image data for lines of image data are sequentially loaded into the printhead, wherein if the specified print mode is the first print mode, image data for a first group of light sources corresponding to the first subset are loaded, and if the specified print mode is the second print mode, image data for the first group of light sources are first loaded, and then image data for a second group of light sources corresponding to the light sources in the second subset that are not in the first subset are loaded.

Abstract: A method for reducing artifacts in an electrophotographic printing system includes receiving a print job including image data for a set of pages. The electrophotographic printing system is used to print a block of pages from the print job to provide corresponding printed pages. Image data for the block of pages is analyzed to determine a cross-track image profile for each page in the block of pages. Image data for a compensation image and a number of compensation images are determined, wherein the compensation image has a cross-track image profile which has an inverted shape relative to an average of the cross-track image profiles for the block of pages. The printing of the compensation images reduces image burn-in artifacts which result from the printing of the block of pages.

Abstract: A method for reproducing an out-of-gamut spot color includes determining a color gamut for a color printer, and specifying a spot color by color coordinates in a three-dimensional color space. A first target color is determined corresponding to a color having a minimum color difference to the specified spot color, and a second target color is determined corresponding to a color on the color gamut surface having a hue value equal to a hue value of the specified spot color. A path is defined on the color gamut surface connecting the first target color and the second target color, wherein a control parameter is used to specify a relative position along the defined path. A user interface is provided enabling a user to adjust the control parameter to specify an aim color.

Abstract: A method for reproducing an out-of-gamut spot color includes determining a color gamut for a color printer, and specifying a spot color by color coordinates in a three-dimensional color space. A first target color is determined corresponding to a color having a minimum color difference to the specified spot color, and a second target color is determined corresponding to a color on the color gamut surface having a hue value equal to a hue value of the specified spot color. A path is defined on the color gamut surface connecting the first target color and the second target color, wherein a control parameter is used to specify a relative position along the defined path. A control parameter prediction function is provided which computes a predicted control parameter value as a function of color coordinates. The predicted control parameter value is used to determine an aim color for reproducing the spot color.

Abstract: A method for reducing image burn-in artifacts in an electrophotographic printing system, includes receiving a print job including image data for a set of pages to be printed. The pages are analyzed to determine that the image data for a sequence of pages in the print job are similar. The similar pages are printed using a pattern of lateral translations wherein the image data is laterally translated such that it is printed at a different lateral position on the printed page. The similar pages can also be printed using a pattern of page orientations including a first page orientation and a second page orientation, wherein the image data for the second page orientation is rotated 180 degrees relative to the image data for the first page orientation.

Abstract: A printhead in a digital printing includes an array of light sources for exposing a photosensitive medium moving past the printhead. Artifacts are reduced in a high-speed print mode by defining first and a second power level control values that differ by at least 20%. The light sources used to print odd-numbered image pixels are activated responsive to the first power level control value and the light sources used to print even-numbered image pixels are activated responsive to the second power level control value.