Abstract: A gray scale ink jet printing method and apparatus which produce a high quality images having varying color intensities are disclosed. This is achieved by using a clear phase change ink base and a plurality of colored phase change inks with varying amounts of black dye, thereby producing multiple gray scale levels of black in images with substantial contrast between the imaged and non-imaged areas that are used in medical diagnostic imaging applications.

Abstract: A solid ink stick feed system for use in a color printer is disclosed that utilizes a plurality of ink stick feed receptacles in an ink stick feed bin of predetermined shapes corresponding to the plurality of shapes of the ink sticks such that an incorrectly matched ink stick shape or incorrectly oriented ink stick is retained in a raised position to indicate to the printer operator that the ink stick should be removed and to facilitate grasping and removing such ink stick.

Abstract: Phase change ink additives are disclosed which comprise quaternary ammonium salts that are extremely useful in producing phase change inks with increased specific conductance. Suitable and adjustable specific conductance is necessary for reliable functioning of electronic type ink level sensing systems used in phase change ink jet printers. Phase change inks may also be encoded for type by virtue of their specific conductance.

Abstract: Urethane resins are made by reacting selected nucleophiles, including alcohols, with an isocyanate. The order of addition of the isocyanate and the different nucleophiles can tailor the distribution of mixed urethane molecules in the final resin product. The final resin product can be colored or uncolored and include a toughening agent. The isocyanate-derived resin materials are useful as ingredients as phase change ink carrier compositions used to make phase change ink jet inks.

Abstract: Improved apparatus and methods for forming a layer of material over a surface of a previously-formed cross-section of a three-dimensional object in anticipation of forming a next cross-section of the object out of the layer. A volume of material, including at least some excess material, is placed over the surface, and the excess material is swept off by placing the excess material in the predetermined path of a sweeping member, the path being substantially in a plane spaced from a working surface of material. The member may be directed to sweep the excess material away through a successive number of sweeps, which may vary for each cross-section, at least a velocity which may vary for each sweep. Additionally, the clearance between the member and the surface of the previous cross-section may vary for each sweep. A "winged" member is also provided, comprising two legs extending from a base, and a "Trident" embodiment is also provided, comprising three legs extending from a base.

Abstract: A method for increasing resolution in a image printed by an ink jet printer is provided. The method selectively removes painted pixels from a bit map to ensure that no two adjacent pixels are painted by the same ink jet. The method removes painted pixels in a manner that preserves the edges of characters and other features. The resulting processed bit map ensures that an individual print head jet always addresses at least one non-painted/blank pixel after each painted pixel it fills. This allows the speed of the receiving surface relative to the print head to be increased to thereby allow for greater resolution in the printed image for a given print time.

Abstract: An improved stereolithography system for generating a three-dimensional object by creating a cross-sectional pattern of the object to formed at a selected surface of a fluid medium capable of altering its physical state in response to appropriate synergistic stimulation by impinging radiation, particle bombardment or chemical reaction, information defining the object being structurally specified to reduce curl, stress and distortion in the ultimately formed object, the successive adjacent laminae, representing corresponding successive adjacent cross-sections of the object, being automatically formed and integrated together to provide a step-wise laminar buildup of the desired object, whereby a three-dimensional object is formed and drawn from a substantially planar surface of the fluid medium during the forming process.

Abstract: A phase change ink carrier composition is disclosed which includes a Diels-Alder polymerization precursor wherein the composition forms a low viscosity liquid at temperatures in the range from about 90.degree. C. to at least about 160.degree. C., and forms a malleable material at temperatures from about 40.degree. C. to about 80.degree. C., and a solid at temperatures less than about 30.degree. C.

Abstract: Urethane resins are made by reacting selected nucleophiles, such as alcohols including a hydroxyl containing toughening agent, with an isocyanate. A colored urethane resin is combined to form a phase change ink. The order of addition of the isocyanate and the different nucleophiles can tailor the distribution of di-urethane and mixed urethane/urea molecules in the final resin product. The isocyanate-derived resin materials are useful as ingredients as phase change ink carrier compositions used to make phase change ink jet inks.

Abstract: This invention relates to the stepwise layer-by-layer formation of a three-dimensional object through application of the principles of stereolithography and to the automatic detection of surface features of each layer of a three-dimensional object to manufacture parts more reliably, more accurately and more quickly. Automatic detection of trapped volume regions and size of solidified cross-sectional regions are disclosed. Automatic selection of recoating styles is made based on(1) the detected regions, (2) empirically or otherwise determined optimum recoating styles for different types of regions, and (3) a look-up table, other correlation system, or processor for associating recoating style information with laminae containing particular identified regions.

Abstract: The invention involves an improved system for producing a three-dimensional object by forming successive cross-sections of the object from a material which is normally solid but which may be made flowable, including using data manipulation for converting a three-dimensional object representation into cross-sectional representations.

Abstract: A photochromic phase change ink composition that contains (A) at least one selected polymeric and photochromic yellow phase change colorant and (B) a phase change ink carrier composition comprising (1) a resin selected from the group consisting of a urethane resin, a mixed urethane/urea resin and mixtures thereof; and (2) a mono-amide.

Abstract: Urethane resins are made by reacting selected nucleophiles, including alcohols, with an isocyanate. The order of addition of the isocyanate and the different nucleophiles can tailor the distribution of di-urethane and mixed urethane/urea molecules in the final resin product. The isocyanate-derived resin materials are useful as ingredients as phase change ink carrier compositions used to make phase change ink jet inks.

Abstract: A phase change ink composition comprising a phase change carrier composition, at least one compatible phase change magenta colorant material, and at least one organic sulfonic acid compound is disclosed. The sulfonic acid stabilizes the magenta dye.

Abstract: An ink jet array print head (101) includes four media-width linear ink jet arrays (100). Ink flows from four sets of manifolds (106) through acoustically matched inlet filters (116), inlet ports (117), inlet channels (118), pressure chamber ports (120), and ink pressure chambers (122). Ink leaves the pressure chambers through outlet ports (124) and flows through oval outlet channels (128) to orifices (108), from which ink drops (110) are ejected. The ink pressure chambers are bounded by flexible diaphragms (130) to which piezo-ceramic transducers (132) are bonded. To minimize inter-jet cross-talk caused by pressure fluctuations in the manifolds, compliant walls (150) form one wall along the entire length of each manifold. An improved ink feed system (210) supplies four colors of ink to the print head.

Abstract: Phase change ink additives are disclosed which comprise quaternary ammonium salts that are extremely useful in producing phase change inks with increased specific conductance. Higher specific conductance is necessary for reliable functioning of electronic type ink level sensing systems used in phase change ink jet printers. Phase change inks may also be encoded for type by virtue of their specific conductance.

Abstract: Phase change carrier compositions made from the combination of at least one urethane resin; at least one urethane/urea resin; at least one mono-amide; and at least one polyethylene wax are disclosed. The order of addition of the reactants to form the reactant product urethane resin and urethane/urea resin permits the tailoring or design engineering of desired properties.

Abstract: A method and system media sheet handling in an electrophotographic color desktop printer are disclosed wherein a media sheet is imaged with toner on both sides of the media sheet without smudging or remelting the images. The temperature of the fusing roller and the pressure roller are controlled to keep the pressure roller temperature below the toner cold offset temperature.

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.