Abstract: Color printing characterized by high color density and color contrast is provided by jetting an ink composition composed of an optically clear, phase change base material and a primary subtractive color dye which is soluble in the base material onto the surface of a printing medium to form a multiplicity of closely spaced color dots or spots arranged to define a line or character on the medium. Each dot consists of one or more well defined, optically clear, semitransparent color layers each of which has a different color so that the observed color of each dot is a true subtractive mixture of the colors in the layers. Specific ink compositions are also disclosed.

Abstract: A solid ink delivery system for supplying sticks of solid ink to a ink jet printer is disclosed. The solid ink delivery system includes a delivery assembly for each color ink stick supplied to the printer. Each delivery assembly includes a tube assembly where the ink sticks are stacked prior to their delivery to the printer. A triggerable ink stick feed assembly is provided for normally holding the in sticks in place. When triggered, the ink stick feed assembly releases the bottommost ink stick or sticks to an opening in the printer adapted to receive them, and restricts the movement of the above stacked ink sticks. The solid ink delivery system is adapted for use with a moving print head having a number of reservoir openings each adapted to receive ink sticks of a different color. A positioning means aligns the print head so the reservoir openings are under the tube assemblies that supply them with the appropriate color ink.

Abstract: Color printing characterized by high color density and color contrast is provided by jetting an ink composition composed of an optically clear, phase change base material and a primary subtractive color dye which is soluble in the base material onto the surface of a printing medium to form a multiplicity of closely spaced color dots or spots arranged to define a line or character on the medium. Each dot consists of one or more well defined, optically clear, semitransparent color layers each of which has a different color so that the observed color of each dot is a true subtractive mixture of the colors in the layers. Specific ink compositions are also disclosed.

Abstract: A printed record in color comprises a transparent sheet on which is jet-printed subtractive color inks in layers of different color. The inked surface of the transparent sheet is adhered to the surface of an opaque backing sheet, usually white in color, so that the backing sheet reflects ambient light back through the ink layers and the transparent sheet so as to provide a color image visable through the transparent sheet that is characterized by high color density and brightness.

Abstract: A rotary ink jet printer can print at high speed in black and white as well as in color using hot-melt inks. The printer includes a rotary print wheel which supports a plurality of ink jetters distributed around its periphery. The jetters are divided into color groups with the jetters in each group drawing ink from a separate chamber of an ink reservoir with the different chambers containing different-colored inks. Each jetter can be aimed separately from all of the other jetters in the print wheel in a direction parallel to the rotary axis of the wheel as well as in a direction perpendicular thereto and tangent to the print wheel, enabling the jetters in the different groups during each revolution of the print wheel to print in a plurality of colors on a plurality of different lines of a recording medium advancing as a cylinder past the periphery of the print head. A mechanism for automatically aiming the jetters on the print wheel is also disclosed.

Abstract: A printed record in color comprises a transparent sheet on which is jet-printed subtractive color inks in layers of different color. The inked surface of the transparent sheet is adhered to the surface of an opaque backing sheet, usually white in color, so that the backing sheet reflects ambient light back through the ink layers and the transparent sheet so as to provide a color image visable through the transparent sheet that is characterized by high color density and brightness.

Abstract: A sheet-feed mechanism (10) for a rotary print head (12) includes a track (16) that defines a paper path in the form of a partial circular annulus. Belts (40 and 42) carry tabs (36, 38, 72, and 74) that support the lower end of a paper sheet, and movement of the belt causes the tabs to raise the paper sheet as it is printed. A guide structure (60) keeps the paper sheet in the proper cylindrical shape until it has left the track, at which time a curved portion (67) of a cam post (66) urges the paper out so that it pops open to a flat shape and falls into a tray (70).