Abstract: An ink includes a C10 to C26 fatty acid and a microcrystalline wax, the ink exhibiting greater scratch resistance than a conventional ink as measured by scratch and fold testing.

Abstract: There is described a method of operating an aqueous ink jet printing apparatus. The printing apparatus includes a member defining a reflective imaging surface wherein the imaging surface is substantially white or grey in the visible spectrum and wherein the imaging surface has an optical density variation of less than about 0.3. The method includes a photosensor array disposed to receive light reflected from the reflective imaging surface. The method includes ejecting aqueous ink onto the reflective imaging surface using a printhead and forming aqueous ink drops on the surface of the rotating member. The method includes generating image data from the reflecting imaging surface using the photosensor array.

Abstract: An inkjet printer includes an electrode in either a printhead or an image receiving member that is operatively connected to a waveform generator. During operation, a controller operates the waveform generator to generate an electrostatic field between the printhead and the image receiving member during operation of inkjets in the printhead to eject ink drops. The controller operates the waveform generator to reduce an amplitude of the electrostatic field while the ink drops travel toward the image receiving member during a time when satellite ink drops can be formed from the ejected ink drops. The controller subsequently operates the waveform generator to generate the electrostatic field while the ink drops are in flight after formation of the satellite to accelerate the ink drops and satellites towards the image receiving member.

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 mechanism enables inkjets in a printhead to be operated to eject ink in an effort to replace ink exposed to ambient conditions with ink from within the printhead. The mechanism includes a controller configured to operate an intermediate imaging member to rotate to align a plurality of apertures with inkjets on a printhead. The inkjets are operated to eject ink through the plurality of apertures and ink from within the printhead replaces the ejected ink without impacting the formation of subsequent ink images.

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 mechanism enables inkjets in a printhead to be operated to eject ink in an effort to replace ink exposed to ambient conditions with ink from within the printhead. The mechanism includes a controller configured to operate an intermediate imaging member to rotate to align a plurality of apertures with inkjets on a printhead. The inkjets are operated to eject ink through the plurality of apertures and ink from within the printhead replaces the ejected ink without impacting the formation of subsequent ink images.

Abstract: A method of operating a printer produces duplex images in print jobs including ink images to be printed to tabbed, hole-punched, and differently sized media sheets with improved throughput. The method synchronizes a media transport to insert a differently sized media sheet with reference to the type of media sheet, enabling the media sheet to contact a portion of the roller bearing substantially less release agent than the rest of the roller, minimizing release agent transfer to a second side of the media sheet.

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 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.

Abstract: 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.

Abstract: 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.

Abstract: A printhead enables surface treatment fluid to be applied to the face of the printhead through at least one aperture located in the printhead faceplate. The printhead receives pressurized surface treatment fluid, which flows through a reservoir in the printhead, through at least one channel in the jet stack, and out the at least one aperture onto the surface of the faceplate. The surface treatment fluid is spread across ink apertures in the faceplate to disable ink from drooling from the ink apertures.

Abstract: 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.

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: 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.