Abstract: A media sensing system monitors the movement of media along the media pathway (76) as a sheet of printing medium (56) is transported through the printer 50. The media sensing system permits a hand fed sheet of printing medium (56) to be detected by a sensor (302) and signal to be sent to inactivate a print media pick roller (122) that automatically feeds print media. The sensing system senses the transport of print media (56) by print media transport rollers (140, 142) detecting media sheet size, activates the transfer process of an image from the liquid intermediate transfer surface on the transfer drum (54) to a sheet of print medium (56) after pausing the sheet of print medium to synchronize its movement along the media pathway with the imaging process, and activating the preheater (60) to heat the print medium (56) prior to image transfer and fusing. The sensing system senses the exit of the print medium (56) from the media exit rollers (212, 220) for delivery to an output tray (68).

Abstract: A phase change ink transfer printing apparatus (10) applies a liquid intermediate transfer surface (12) to a heated drum (14, 28). Because the intermediate transfer surface is a thin liquid layer, molten ink drops (122) striking it flatten and spread out (110, 112, 114, 130) prior to cooling and solidifying as an ink image (26, 130) at the drum temperature. After the ink image is deposited, a print medium (21, 132), such as a transparency film, is fed into a nip (22) formed between the heated drum and an elastomeric transfer roller (23). As the drum turns, the print medium is pulled through the nip to transfer the ink image to the print medium. When in the nip, heat from the drum and print medium combine to heat the ink in accordance with a process window (90), making the ink sufficiently soft and tacky to adhere to the print medium but not to the drum. The ink drops comprising the ink image have a desired diameter to height ratio of from about 1.

Abstract: A particulate filter (16) is provided within an inlet channel (22) of an ink jet (14). The filter is oriented generally in the direction of ink flow to provide a greater filter surface area. Positioning the filter within the inlet channel results in reduced acoustic crosstalk, more effective filtering, and more efficient purging of the filter itself because of the relatively high ink pressure drop across the filter in the channel. Positioning the channel vertically assists the buoyancy of the bubble movement during operation and purging.

Abstract: A print head (216) tilt angle positioner (258) includes a scroll cam (344), a tilt arm (332), a flexure (334), a tilt angle adjuster (336), and a biasing spring (338). The tilt arm and the print head are attached to a shaft (220) that rotates the tilt arm and the print head together between printing, maintenance, and shipping tilt angle positions to control the distance of the print head from the image receiving drum.

Abstract: An image transfer ink-jet printer (10) employs an image receiving drum (12) that rotates relative to a ink-jet array print head (26) spanning the full width of the drum. An encoder disk (70) is coupled to the drum to coordinate ink drop ejection with precise angular rotational increments of the drum. The encoder disk has an alternating transparent/opaque pattern with a pitch that is one-half the desired resolution of the printer. A photo-optical detector (72) senses the alternating pattern and sends an asymmetrical signal to a duty-cycle correction circuit (140) that generates a symmetrical signal having a frequency double the one received from the photo-optical detector.

Abstract: A system and method for printing a predetermined image onto a substrate includes steps or structure for determining a first area on the substrate where a colorant is to be deposited; determining a second area which is immediately adjacent to the first area; depositing an image-enhancing precoat over the first area and the second area; and depositing a colorant on the exposed surface of the image-enhancing precoat substantially so as to be over the first area, whereby a border of precoat material will be defined about the printed image on the substrate. A second aspect of the disclosure involves sealing a printed image on a substrate by applying an aftercoat.

Abstract: A digital halftone pattern geometry adapted not to the characteristics of variable dot size printing presses but to the operating characteristics of the printer itself achieves a high degree of image quality. Techniques for creating the halftone pattern geometry include linear spot growth to provide uniform darkening and the use of a super-cell structure to maximize the number of tint or gray scale levels. A preferred super-cell structure is of hexagonal dispersed-dot form to reduce low frequency artifacts by spreading them over a greater number of frequencies. An increase in addressability to enhance printer resolution in the direction of the path of print medium travel with no change in dot size will cause placement of overlapping dots when a darkening of consecutive pixels in the direction of print medium travel is called for in the halftone pattern.

Abstract: The present invention provides an ink jet print head capable of fast, efficient and consistent printing. Such ink jet print heads include an ink ejecting component which incorporates electropolished surfaces. Electropolishing techniques useful in the production of such ink ejecting components are also discussed.

Abstract: A method and an apparatus (10) for cleaning an ink jet print head (12) draws contaminates from orifices (20) in the print head onto an orifice plate (14) and then wipes the orifice plate. The maintenance apparatus includes a purge cap (24) that has a recessed region (40) with an open end (36). The top side margins (42) of the open end define a periphery (44) around which a seal (60) is positioned. A positioning system (30) urges the orifice plate against the seal. A heating system (128) and a vacuum system (74) cooperate to create a differential pressure across the orifices to draw contaminates carried by liquid ink out of them and onto the orifice plate. A resilient wiper assembly (26) including a spring-mounted wiper blade (78) is positioned in and nominally extends outwardly of the recessed region of the purge cap. The positioning system moves the purge cap downwardly against the orifice plate so that the wiper blade engages and wipes the contamination from the orifice plate.

Abstract: An aqueous phase change ink contains a water dispersible sulphonated polyester gloss agent and a selected concentration of hyperthermogelling component that causes the ink to gel when its temperature is increased to its thermo-inversion point or when the concentration of the hyperthermogelling component is increased by evaporation, or substrate absorption, of water from the ink. The ink may be jetted directly onto a heated and/or absorptive substrate or jetted onto a cooler and/or hydrophobic surface before being transferred to the substrate. The thermo-inversion point is preferably about ambient temperature, and the preferred hyperthermogelling component is a nonionic surfactant, such as an ethylene oxide propylene oxide block copolymer surfactant.

Abstract: A system and method for printing a predetermined image onto a substrate includes steps or structure for determining a first area on the substrate where a colorant is to be deposited; determining a second area which is immediately adjacent to the first area; depositing an image-enhancing precoat over the first area and the second area; and depositing a colorant on the exposed surface of the image-enhancing precoat substantially so as to be over the first area, whereby a border of precoat material will be defined about the printed image on the substrate. A second aspect of the disclosure involves sealing a printed image on a substrate by applying an aftercoat.

Abstract: A method of thermal transfer printing on a substrate includes the steps of determining, on a pixel by pixel basis, where colorant is to be located on the substrate; applying an image-enhancing precoat to each pixel where colorant is to be located, as well as to at least one immediately adjacent pixel; and depositing a colorant onto the precoated predetermined pixels. The precoating that is applied to the immediately adjacent pixels helps retain the precoating to the substrate, among other advantages. A second method, for printing on a rough substrate, includes steps of applying an image enhancing precoat so as to form bridges across valleys of said rough surface; and subsequently depositing a colorant onto the precoat. A third printing method includes the steps of applying a precoat to the substrate which has one or more voids defined therein; and depositing a colorant onto the precoat so as to bridge over the voids in the precoat. Related systems and printed products are also disclosed.

Abstract: A system and method for printing a predetermined image onto a substrate includes steps or structure for determining a first area on the substrate where a colorant is to be deposited; determining a second area which is immediately adjacent to the first area; depositing an image-enhancing precoat over the first area and the second area; and depositing a colorant on the exposed surface of the image-enhancing precoat substantially so as to be over the first area, whereby a border of precoat material will be defined about the printed image on the substrate. A second aspect of the disclosure involves sealing a printed image on a substrate by applying an aftercoat.

Abstract: An ink stick shape for use in a printer ink stick feed chute is disclosed wherein the opposing sides of the ink stick are tapered or angled from the horizontal so that at least one area intermediate the top and the bottom of the ink stick is a greater distance from the horizontal than the junction of the side walls and the bottom of the ink stick. The ink stick shape or geometry may be keyed to a particular color.