Abstract: Addressing apparatus that electronically address data sites of a digital array include electrodes (36, 38) manufactured with consistent electrical contact quality on the surfaces of projections (30) from a substrate (14). This is accomplished by providing such electrodes with portions that are offset to follow regions of more equal slope on the projections. The offset electrodes are of more consistent structural and electrical contact quality and thereby facilitate an increase in the yield of the manufacturing process.

Abstract: A thermal transfer printer (10) includes multiple media trays (16, 120, 126) each encoded to communicate to a printer controller (46) via sensors (132, 134, 136) a print medium size and type contained in the tray, and a pair of thermal transfer ribbon (24) sensors (44,45) to communicate whether the ribbon includes a pre-coat material panel (34). A printer driver responsive to the media size and type sensors and the thermal transfer ribbon sensors to causes pre-coat material to be applied to coated or plain paper print media but not to transparency print media. Post-rendering color correction is provided for color images printed on various media type and pre-coat combinations. The printer driver prevents an image from printing when potentially wasteful conditions are detected in response to a print job request, forced tray selection, or automatic tray switching selection.

Abstract: A cylindrical drum is rotatable about a drum axis for supporting a print medium during printing. A print head has a plurality of printing elements for printing image elements of a predetermined color at a predetermined image-element printing rate. The drum is rotated about the drum axis at a predetermined speed such that alternate image-element locations are addressed by each printing element during each rotation of the drum at the predetermined printing rate. The drum rotates two revolutions at each print-head location along the axis, and all image-element locations are addressed.

Abstract: A FRU assembly (10) comprises a melt chamber (20) including multiple subchambers (30) in which sticks of phase change ink (38, 40) are inserted and melted. Melted ink flows through apertures (54) to a reservoir (28) comprising multiple compartments (56). Each compartment contains a channel (90) and a siphon plate (114) that allow a siphon action that siphons melted ink in the compartments to an orifice (100) that leads to an ink jet print head (16). Heaters (52, 82, and 142) under the control of a CPU (154) melt the ink and keep the melted ink at a desired temperature during various modes of operation.

Abstract: An improved electrode structure (42', 42") for an addressing structure using an ionizable gaseous medium has a plurality of plasma discharge channels (20') and a reference electrode (30', 30") and a row electrode (62') extending along each channel. The channels open into a plenum (118) for exhausting gases from the channels and introducing into the channels an ionizable gaseous medium at a predetermined pressure. The reference electrodes and the row electrodes enter from opposite ends of the channels, and the reference electrodes cross below the plenum. The row electrodes have an end (110) spaced from the ends (102) of the channels. The end of the row electrodes is separated from the end of the channels by a first distance (D) adequate to prevent undesirable plasma discharge while the electrode structure is operating. In a first embodiment (42') the reference electrodes have an end (112) spaced from a first perimeter seal (106).

Abstract: An apparatus for addressing data storage elements (16) uses an ionizable gas excited by an AC energy source to store an analog datum in and read an analog datum out of each of the storage elements. The storage elements are defined by the overlapping areas of multiple column electrodes (18) extending in a common direction on a first substrate (48) and multiple channels (20) extending in a common direction on a second substrate (54). A layer of dielectric material (46) separates the first and the second substrates, which are positioned face-to-face and spaced-apart with the direction of the channels transverse to that of the column electrodes. Each of the channels is filled with an ionizable gas and includes two row electrodes electrically isolated from each other. At least one of the row electrodes is isolated from the gas by a dielectric coating (65) to prevent nonuniform current flow in certain regions along the length of a channel.

Abstract: A print drum and associated clamping assembly is provided for use in printing or similar operations. The print drum is characterized by uniform thermal characteristics and is constructed from a material having thermal diffusivity of greater than about 1.3.times.10.sup.-5 m.sup.2 /sec. The print drum may moreover have a highly reflective surface that permits optical sensors to distinguish between the drum and substrate surfaces. Clamping sections of a substrate clamp assembly project through slots provided in the print drum and are raised and lowered to release and clamp a substrate respectively. Other constituents of the clamp assembly are mounted in the hollow interior of the print drum. The print drum and associated clamping mechanism is especially suitable for use in ink jet printing apparatus utilizing thermal phase change inks.

Abstract: A color processing system is provided that specifies color in a standardized, perceptually uniform color space and resolves color differences between input and/or output devices. The color processing system utilizes a color mapping techniques to adjust the results of color mapping to fit the color gamut of the output device. The color processing system may be implemented as a color rendering dictionary in a PostScript.RTM. Level 2 interpreter. An additional feature involves adaptation of PostScript.RTM. Level 1 applications to take advantage of the improved color processing system and PostScript.RTM. Level 2 flexibility.

Abstract: A mechanical holder for receiving an integrated circuit chip and an etched circuit board probe and holding them in predetermined relative positions includes an alignment block including alignment elements and having a main surface against which the probe is positioned, and a chip receiver having a main surface and including alignment elements that are complementary to the alignment elements of the alignment member. The chip receiver is attached to the alignment member with the main surface of the chip receiver in confronting relationship with the main surface of the alignment member and with the alignment elements of the chip receiver in registration with the alignment elements of the alignment member. The chip receiver defines a cavity that opens at its main surface.

Abstract: An ink jet printer (10) having a print head (14) for directing an ink jet toward a sheet of paper (16) includes automatic print head spacing apparatus (80) that holds the print head apart from the sheet of paper by a preselected distance. In a preferred embodiment, the printer includes a rotatable drum (20) for supporting the sheet of paper and media securing system (24) of a first predetermined thickness for securing the paper to the drum. The print head is positioned at the preselected distance after a major surface (130) of the print head engages and is pushed back by the media securing system.

Abstract: The present invention provides a stable, high performance system for driving one or more masses in precise incremental movements. More particularly, the present invention provides a method and system for deriving and implementing motion profiles that govern the movement of one or more masses, such as a printer drum as it is indexed along a rotational path by a stepper motor.

Abstract: A triggerable ink transfer system that simultaneously transfers ink from a plurality of ink preload chambers to corresponding load chambers and ink reservoirs is disclosed. The delivery system permits an untrained operator to safely load ink without inadvertently interchanging different types (e.g. colors) of ink, and without inadvertently overfilling any of the ink reservoirs. A processing unit that coordinates ink delivery system monitoring and control features is in communication with an operator interface unit that provides ink loading instructions to the operator.

Abstract: The present invention includes a cathode-ray tube (10) capable of providing a high-brightness, high-resolution large screen display that is compatible with, for example, field sequential liquid crystal color display systems and monochrome imaging systems. Preferably, the tube includes a small-diameter cathode assembly (14 of 110) with an adjacent small-diameter control grid electrode (38 or 114). The small diameters of the cathode assembly and the control grid electrode result in relatively little capacitance and are, therefore, compatible with relatively high video signal bandwidths. A thick accelerating electrode (66 or 150) is positioned adjacent the control grid electrode to prefocus the electron beam and, thereby, form it with relatively low spherical aberration. In a preferred embodiment, the electron beam is modulated in a push-pull manner by applying a video modulation signal and its inverse to the cathode and the control grid electrode.

Abstract: A probe for testing integrated circuits includes a stiff elastic substrate including a conductive plane, the substrate having a major portion with fingers projecting therefrom in cantilever fashion. A layer of dielectric material is adhered to the substrate and has a main surface remote from the substrate. A plurality of conductor runs are adhered to the layer of dielectric material at the main surface thereof. The conductor runs extend over at least some of the fingers and are configured to form transmission lines when the conductive plane is connected to a reference potential level.

Abstract: A multi-orifice ink jet print head array (32) includes multiple drive circuits that drive respective PZTs (16) to cause ink drops to be ejected from respective orifices (28). Each drive circuit includes a voltage divider (36) having a resistor R.sub.S. The ink drop ejection velocity is controlled by selecting an appropriate value of R.sub.S for each voltage divider, thereby compensating for imperfections in manufacturing of the print head array. The value of a particular R.sub.S is selected by temporarily connecting the corresponding voltage divider (36A), in which the value of R.sub.S is R.sub.I, to assessment circuit (56). The assessment circuit includes a potentiometer (66) with resistance value R.sub.POT. Ink drops are ejected at a rapid periodic rate as a camera (102) records the position of the ink drops with respect to a graticule (94) at the time a strobe (100) flashes. The value of R.sub.POT is adjusted until the ink drops are on the graticule as viewed on a monitor (108), at which time R.sub.POT =R.

Abstract: Methods and apparatus for processing printed substrates having a phase change ink layer of non-uniform thickness are disclosed. Application of a combination of heat and pressure reorients the printed ink layer to provide a layer having a substantially uniform thickness and flat surface conformation, at least in the area of each discrete color. A release surface (55) is positioned adjacent the printed ink layer during processing. A resilient contact surface (56) is also provided to facilitate reorientation of the printed ink layer. Mechanical buffing of the processed, printed substrate improves image quality. Application of a light transmissive, protective coating that overlays the printed ink layer also improves image quality.

Abstract: A fixing and developing apparatus in which sheet material to be treated is passed through a high pressure nip defined by a pair of rollers. At least one of the rollers may have a composite construction. The composite roller includes an elongated tubular shell with a pressure applying external surface, an elongated core positioned within the tubular shell, and an elastomeric material disposed between the core and shell to support the shell on the core. The core may be of a number of configurations and may increase in transverse cross-sectional dimension from the respective ends of the core toward the center of the core. The core may taper continuously or in discrete steps from its center toward its first and second ends. In addition, the core may have a longitudinal cross-section with a crown in the shape of a beam deflection curve for a simply supported, uniformly constant cross-section beam. The shell may be similarly configured along its interior surface.

Abstract: A variable transition time generator has a differential emitter follower circuit that has a push-pull signal at the inputs for driving each end of a timing capacitor. An independently variable timing current source is coupled to each end of the timing capacitor. A differential buffer amplifier passes the voltage across the timing capacitor to an output. A d.c. compensation circuit has a statically biased emitter follower pair of transistors that are driven independently by a pair of variable compensation current sources that track the independently variable timing current sources, the output of which is combined with the output of the buffer amplifier. Also combined with the output of the buffer amplifier is a step correction output derived from the differential input signal. The result is a high speed variable transition time generator that simultaneously produces independently controllable opposite polarity transitions.

Abstract: A light shutter system (10) incorporates a liquid crystal cell (12) operating as a variable optical retarder to selectively produce opaque and transmissive optical states corresponding to the respective first and second amounts of optical retardation of the variable optical retarder. The cell switches between a residual amount of retardation and an increased amount that equals the sum of half-wave retardation and the amount of residual retardation to provide a shutter system whose system retardation switches between zero retardation and half-wave retardation and thereby produces opaque and transmissive states with an optimal contrast ratio. The cell is positioned between a linear polarizing filter (14) and an elliptical analyzer (16), the latter including a linear polarizing filter (20) and an optical retarder (18) of fixed value.

Abstract: An ink jet print head cleaning and maintenance system has a purge chamber for applying a vacuum to a nozzle orifice surface. A specialized baffle diverts ink entering the purge chamber away a vent port through which the vacuum is drawn. An elongated wipe engages and wipes the orifice surface and is preferably moved at an extremely slow rate across the surface to enhance the wiping operation. An air knife directs a narrow stream of air across a portion of the nozzle orifice surface with air from the air stream being scanned across the surface for cleaning purposes. A specialized drip edge is positioned beneath the orifice surface for directing drops of ink away from the ink jet print head, the drops of ink being generated during the cleaning procedures. A mechanically simple cam mechanism coupled to a rotatable drum of the printer may be used to shift the maintenance system against the nozzle orifice surface for cleaning purposes.