摘要:
A leveling and spreading system has been developed that enables the speed and position of the web to be determined from a sensor on a first roller. In a duplex print process, the first roller also reduces a temperature of the media web and an ink image printed in the first side print operation to within a first predetermined temperature range. A second roller modulates the temperature of the media web and ink ejected onto the media web immediately before the web enters the leveling and spreading system to within a second predetermined temperature range to enable uniformity of the ink and web temperatures for spreading the ink in a nip formed with a third roller.
摘要:
A method generates a test pattern on an image receiving member that is less perceptible to human observation, but still detectable by an imaging device within a printer. A method implemented in the printer analyzes image data of the dashes in the test pattern that were randomly distributed in the process direction within an area of the image receiving member to identify positions for printheads in the printer and detect missing inkjets in the printheads.
摘要:
A method enables an operator to detect misalignment of printheads that eject clear ink in an inkjet printer. The method prints a first test pattern with a first color of ink and then prints a second test pattern of clear ink on top of the first test pattern. The ink of the first and the second test patterns is then spread to enable the clear ink to be dispersed in interstitial spaces in the ink of the first color. An operator is then able to detect the spatial relationship of predetermined marks in the second test pattern to predetermined marks in the first test pattern. The predetermined marks of the first and the second test patterns are arranged to enable an operator to detect a misalignment distance and the inkjet printer uses the misalignment distance entered by the operator to adjust the alignment of the printheads that eject clear ink.
摘要:
A method of operating a printer enables a controller in the printer to operate electrical motors for aligning printheads in the printer with greater accuracy. The method includes generating a test pattern on media with a plurality of printheads, identifying a first position for each printhead in the plurality of printheads from test pattern image data, operating an electrical motor operatively connected to one of the printheads to move the printhead in a first direction in the cross-process direction by a predetermined distance, generating a second test pattern on the media, identifying a second position for each printhead, comparing the second position of the printhead with the first position of the printhead to measure a distance moved by the printhead, identifying a first calibration parameter with reference to the predetermined distance and measured distance, and operating the electrical motor with reference to the first calibration parameter.
摘要:
A printer operating method enables a controller to identify process direction errors in an optical imaging system. The method includes identifying a printhead roll error for each printhead in a plurality of printheads in a printer, moving each printhead by an amount that corrects the printhead roll error for the corresponding printhead, generating a plurality of dashes on media with the plurality of printheads as the media moves past the plurality of printheads, identifying a position for each dash in the process direction from image data of the plurality of dashes on the media, identifying a displacement in the process direction for each optical detector in a linear array of optical detectors used to generated the image data of the plurality of dashes, the displacement being identified with reference to the identified positions for the dashes, and operating the printer to compensate for the identified displacements of the optical detectors.
摘要:
A method analyzes image data corresponding to a test pattern generated on an image receiving member by a printer to identify positions for and registration between printheads in the printer. The method includes identifying a process direction position for each row of dashes in a plurality of rows of dashes in image data of a test pattern printed on an image receiving member, the test pattern being formed by each printhead in a printer forming at least one dash in each row of dashes in the plurality of rows of dashes, identifying a center of each dash in a cross-process direction, identifying an inkjet ejector that formed each dash in the row of dashes, identifying a process direction position for each printhead in the printer, identifying a cross-process displacement for each column of printheads, identifying a stitch displacement in the cross-process direction between neighboring printheads in a print bar unit that print a same color of ink, and operating an actuator to move at least some of the printheads in the printer with reference to the identified process direction positions, cross-process displacements, and the identified stitch displacements.
摘要:
An apparatus prints on a continuous web moving in a process direction. A fiducial marker prints on a portion of the web a repeating pattern of fiducial marks at a predetermined spacing along the process direction. At least two printing stations are operatively disposed downstream of the fiducial marker, each printing station including a printhead for placing marking material suitable for a partial image on the web. A photosensor reads a fiducial mark on the web moving relative to the printing station.
摘要:
A method and system compensates for streak defects in an image formed using a raster output scanning device. A reflectance profile is generated from an image generated by the raster output scanning device. Thereafter, a difference profile is determined. The difference profile is determined based upon the generated reflectance profile and a uniform profile. A compensation profile is generated based on the determined difference profile. The compensation profile represents a change in an intensity profile for the raster output scanning device.
摘要:
A printing apparatus has a substantially shiny photoreceptor imaging surface, and a photosensor array disposed to receive specularly-reflected light from the imaging surface. A quantity of toner is placed on the imaging surface, and data is derived based on light reflected from the imaging surface. The reflected light is filtered to a color effectively complementary to the toner color. The system avoids noise caused by diffusely-reflected light from powdered toner.
摘要:
Defects in an image may give rise to visible streaks, or one-dimensional defects in an image that run parallel to the process direction. One known method for compensating for streaks introduces a separate tone reproduction curve for each pixel column in the process direction. A compensation pattern according to this invention ha alignment marks before and after a halftone compensation region. The alignment marks provide alignment between the printer pixel grid and a scanning pixel grid. The line width of each alignment mark and the gray level in each pixel column of each gray level portion is measured and analyzed to produce a local tone reproduction curve for each pixel column and associated line width. The line widths of the alignment marks can be remeasured to adjust the local tone reproduction curves to compensate for the streak defect when printing.