Patent application number | Description | Published |
20080239341 | SYSTEM AND METHOD FOR CONTROLLING CONSISTENT COLOR QUALITY - A system and method control a consistent color quality of overlay colors and single separations of color. The method determines a first error for a first separation of a first color, wherein the first error has a first sign. The method identifies a second error for a second separation of a second color, wherein the second color is a different color than the first color, wherein the second error is based on an actual density value for toner particles printed transferred from the second separation, wherein the second error has a second sign. The method compares the first sign of the first error and the second sign of the second error. The method converges the actual density value of the second separation to a target position when the first sign is a different sign than the second sign. | 10-02-2008 |
20090296175 | TONE REPRODUCTION CURVE LINEARIZATION - A marking device is controlled to mark a media sheet with halftone dots selected from a set of image halftone dot representations. The marking device is controlled to mark a monitored surface with halftone dots selected from a set of control halftone dot representations to form test patches of different nominal marking densities. Measured marking densities are acquired using a density sensor for the test patches marked on the monitored surface. The set of control halftone dot representations is updated based on the measured marking densities and the nominal marking densities. | 12-03-2009 |
20130038657 | In Situ Calibration Of Multiple Printheads To Reference Ink Targets - A method for calibrating in situ a plurality of printheads in an imaging device has been developed. Firing signals operate a plurality of printheads to form ink test patterns on an image receiving member. Reflectance measurements of light reflected from the test patterns and optical density measurements for a portion of the patterns formed by only one printhead in the plurality of printheads are used to adjust the firing signals and enable the printheads to print within a predetermined range about an average reflectance value and a predetermined optical density. | 02-14-2013 |
20130155140 | METHOD AND SYSTEM FOR CORRECTING MEDIA SHIFT DURING IDENTIFICATION OF PRINTHEAD ROLL - A method for aligning a printhead to compensate for printhead roll when an image receiving member moves laterally during printing has been developed. The method includes generating at different times a plurality of marks in a process direction with different inkjets in a printhead and identifying relationships between marks in each plurality. Lateral motion is thereby detected and removed from the analysis identifying the magnitude of the roll corresponding to the locations of the marks in the pluralities of marks. | 06-20-2013 |
20130187972 | In Situ Calibration Of Multiple Printheads To Reference Ink Targets - A method for calibrating in situ a plurality of printheads in an imaging device has been developed. Firing signals operate a plurality of printheads to form ink test patterns on an image receiving member. Reflectance measurements of light reflected from the test patterns and optical density measurements for a portion of the patterns formed by only one printhead in the plurality of printheads are used to adjust the firing signals and enable the printheads to print within a predetermined range about an average reflectance value and a predetermined optical density. | 07-25-2013 |
20130201245 | METHOD OF PRINTHEAD CALIBRATION BETWEEN MULTIPLE PRINTHEADS - A method of identifying positions of a plurality of printheads in a printer is described. The printer identifies the positions of each of the plurality of printheads with reference to image data of a printed test pattern. The printer calibrates one or more printheads using only a single test pattern to correct registration errors in the printheads. | 08-08-2013 |
20140015882 | System and Method for Sub-Pixel Ink Drop Adjustment for Process Direction Registration - A method of operating an inkjet printer reduces ink drop placement errors in a process direction. The method includes generating firing signals for inkjets in a printhead at a first frequency and initiating the generation of the firing signals to a first plurality of inkjets in the printhead at a second frequency, the first frequency being greater than the second frequency. | 01-16-2014 |
20150017271 | Digital Manufacturing System For Printing Three-Dimensional Objects On A Rotating Surface - A printer forms a three-dimensional object on a rotating substrate. The printer includes a first driver to rotate the substrate past at least one printhead at a predetermined velocity and a controller to operate the printhead to eject material onto the substrate to form the object. A second driver is operated to move the position of the printhead perpendicular to the substrate to maintain a predetermined gap between the printhead and the layer of material most distant from the substrate. The second driver is further operable to move the position of the printhead parallel to the substrate to adjust a resolution of the ejected material. The controller interpolates an alternating signal generated from a position encoder to adjust the operation of the printhead based on the rotational position and velocity of the substrate. | 01-15-2015 |
20150017272 | Digital Manufacturing System For Printing Three-Dimensional Objects On A Rotating Core - A printer forms a three-dimensional object on a rotating substrate. The printer includes a frame that supports a cylindrical member and at least one printhead such that the first printhead is positioned to eject material onto an outer surface of the cylindrical member. The frame is movable between a first position that rotatably supports the cylindrical member and a second position that enables transfer of the cylindrical member to and from the frame. A controller operates the printhead to eject material onto the rotating cylindrical member to form the object. The controller interpolates a periodic signal generated from a position encoder to adjust the operation of the printhead based on the rotational position and velocity of the cylindrical member. The controller operates a driver to move the frame to the second position to enable removal of the cylindrical member from the printer. | 01-15-2015 |
20150077454 | SYSTEM AND METHOD OF PRINTHEAD CALIBRATION WITH REDUCED NUMBER OF ACTIVE INKJETS - A method for printhead location identification includes identifying a plurality of amplitudes for a portion of pixel columns in image data generated from a portion of an image receiving surface in which marks formed by an inkjet in the printhead are printed. The amplitudes are generated from a portion of each pixel column including expected locations for a portion of the printed marks in a process direction. The method further includes identifying a cross-process location of the inkjet from a pixel column corresponding to a pixel column with a maximum local amplitude value and storing the location of the inkjet in a memory for printhead registration. | 03-19-2015 |