Abstract: A pressure interconnect package for connecting an integrated circuit chip to an etched circuit board comprising a pressurized stack of circuit elements in which a flexible interconnecting circuit is disposed between the IC chip and the etched circuit board to cause them to make electrical contact upon the application of pressure to the stack.

Abstract: A method and apparatus is disclosed for operating an ink jet print head 14 of the type having an air chamber 64 to which a stream of air is delivered and an ink chamber 32. A valve 48 interrupts the flow of air to the air chamber 64 from time to time, such as after each copy of a print is printed by the print head. This reduces the air pressure within the air chamber 64 and permits ink from ink chamber 32 to enter the air chamber 64 and replenish ink within the air chamber. The ink pressure is increased while the air pressure is reduced. This reduces the time required to replenish the ink. With the ink in the air chamber maintained at a consistent quantity and shape, the convergence of ink drops on printing medium is enhanced.

Abstract: A method and an apparatus provide an optical switching system (10) which provides independent of viewing angle two system optical transmission states of substantially contaminant-free light. The system includes first and second light gates (12 and 12') of which each has associated therewith contaminant light intensity patterns (48 and 66) with points of local maxima (54, 56, 58, 60, 68, and 70) and local minima (62 and 72) in two system optical transmission states. The contaminant light intensity patterns are oriented so that the points of local maxima and minima of the contaminant light intensity patterns of one of the light gates generally align with the respective points of local minima and maxima of the contaminant light intensity patterns of the other light gate. The alignment of contaminant light intensity patterns blocks the transmission of contaminant light in two system optical transmission states, and thereby provides improved viewing angle performance.

Abstract: A field sequential color display system incorporates a color switch which includes a zero to half-wave optical retarder and pleochroic filters to provide an image with high color contrast and resolution over a broad range of display sizes. In a preferred embodiment, a liquid crystal cell which operates between two states of optical retardation comprises the variable retarder to provide a color switch with substantially reduced optical response times.

Abstract: An ink cartridge 10 is described with a rigid, hollow housing 12 within which an ink container assembly is positioned. The assembly includes an ink container 16 mounted, as by heat sealing, directly to an ink container support 18. The support 18 is secured by fasteners 24 to a cap 14 of the housing with a gasket 22 and gasket retainer 20 positioned between the support 18 and cap 14. The gasket retainer 20 includes plural gasket retaining projections 104, 150, 152, 156 and an outer peripheral wall 23 which bears against the cap 14 when the ink cartridge is assembled. The gasket support 20 and ink container support 18 cooperatively interfit. To manufacture the ink container assembly, the ink container support 18 is inserted through an opening 74 in a sheet of ink container forming material. The portions 78 of the ink container material bounding the opening are then secured to a planar mounting surface 72 of the ink container support 18.

Abstract: A liquid crystal cell (100) includes a chiral additive in the liquid crystal material (106) to operate the cell as a rapid starting, high-speed variable optical retarder. The cell is fabricated so that the surface noncontacting directors (116 and 118) of the opposed surfaces of the director alignment layers (112 and 112') of the electrode structures (102 and 104) are tilt-biased in opposite directions. This surface contacting director configuration induces rapid surface noncontacting director (120a, 120b, 120c, 120d, 120e) relaxation without optical bounce when the cell is switched from the field aligned ("ON") state to the partly relaxed ("OFF") state. The chiral additive prevents an inactive cell from relaxing to the splayed topological state, thereby enabling switching operation without a warm-up delay and preventing the surface of the cell from having a mottled appearance when it remains unused.

Abstract: A method of fabricating multilayer printed circuit boards using polymer thick film technology is disclosed which utilizes photoimageable dielectric material between conductive polymer thick film layers and which is capable of producing extremely small and uniformly-sized vias.

Abstract: A resistor formed by a film of resistive material deposited on a dielectric substrate is trimmed by removing resistive material along a line such that the film is divided into at least two discrete areas, one, and only one, of which areas includes two terminal portions of the film.

Abstract: An air assisted hand welding tool for clamping and welding conductors together. The tool includes a handle formed of pivotally connected lever-like members. An air passage is connected to an air pressure source provided in the handle of the hand tool. A valve is manually engaged by the operator (following tactile closing of the electrodes on the conductors) to open the air pressure to an expansion chamber formed between the members. As the chamber pressure is increased, the members are urged to a consistent clamping force thereby to assist the operators normal hand clamping function. A switch in the expansion chamber is connected to the welding circuit and is activated following chamber expansion to initiate welding. The entire welding operation including air assist and welding current initiation are all accomplished by a simple closing motion of the operators hand.

Abstract: A digital signal sampling system is disclosed for reconstructing the time relationship of digital data signals sampled by two sampling clock signals with different unrelated timebases. The digital data signals sampled may be the same data signal or two different data signals sampled simultaneously in two separate sampler circuits at two different unrelated sampling clock frequencies or timebases to produce first and second sampled data signals. A timebase correlation circuit produces first and second time correlation signals in the form of binary level signals in response to the receipt by a last clock pulse detector of first and second store clock signals which are derived from first and second sampling clock signals. The time correlation signals indicate by their binary level the source of the last previous clock pulse of the first and second store clock signals which was received by the timebase correlation circuit.

Abstract: An ink cartridge 10 includes an ink level sensor 38 having a probe supporting structure, such as platform 174, which projects into a collapsible ink container 16 from an ink container support 18. First and second electrical probes 40, 41 are embedded within the structure, with tip portions 188, 190 of the probes 40, 41 being exposed to provide an electrically conductive path through the ink between the probes. Flat closure surface 176, 178 are provided between the exposed portions of the probes against which the container 16 collapses. When the ink container 16 collapses against these surfaces 176, 178, the resistance between the probes increases, is insensitive to ink conductivity, and indicates that volume of ink within the cartridge is low. The platform 174 is supported by tapered necks 180, 182 projecting into the ink container from the ink container support 18.

Abstract: A shadow mask assembly for a cathode-ray tube. The shadow mask assembly includes a taut shadow mask membrane affixed to one edge of a closed frame. The frame is angled inwardly from the edge for increased resistance to buckling. Mounting clips generally aligned with the tube axis are secured to the frame inwardly of the outer edge and project outwardly thereof into engagement with locating holes in the envelope. The clips are deflected inwardly behind the outer edge for disengagement and to permit assembly of the shadow mask into an envelope having an inside dimension close to the outside dimension of the frame.

Abstract: A cable stripper for stripping the protective jacket from the end of a cable. A cable holder secures the cable while a blade, protruding through the guide surface of a blade holder, is urged against the cable and rotated around the cable. The guide surface of the blade holder is continuously biased against the cable surface with the blade protruding to a pre-set depth from the guide surface whereby a consistent depth of cut is achieved.

Abstract: An ink jet printer having an ink jet head unit including a head and a three way valve mounted on a bracket. The bracket is removabley mounted to the printer and allows the unit to be replaced in the field. The valve of the new unit is positioned to close off flow to the head while opening flow from the ink source outlet to a disposal outlet. Upon connection of the new unit to the system, a quantity of ink is flushed through the valve to remove impurities introduced during the connection process. The valve is then adjusted to connect flow of ink to the head while closing off the disposal outlet and thereby avoid contamination of the new head.

Abstract: A method and an apparatus provide an optical switching system (100) which maintains essentially constant transmissivity at its maximum value and develops independent of viewing angle two system optical transmission states of substantially contaminant-free light. The system includes first and second light gates (102 and 104) of which each has associated therewith contaminant light intensity patterns (48 and 66) with points of local maxima (54, 56, 58, 60, 68, and 70) and local minima (62 and 72) in two system optical transmission states. Quarter-wave plates (134 and 136) are positioned between the light gates to develop circular polarization of light propagating between them. The presence of circularly polarized light maintains the system transmissivity at its maximum value while the relative orientation of the light gates is changed to align their contaminant light intensity patterns to block the transmission of contaminant light, and thereby improve the viewing angle performance.

Abstract: An electron beam deflection structure (10) of the traveling wave type includes first and second deflection members (52 and 58) positioned on opposite sides of and extending along the path of an electron beam (26) to deflect the beam in response to deflection signals applied to the deflection members. In a preferred embodiment, both deflection members are of a meander line type which include a plurality of deflection plate segments (74, 76) connected in series by a plurality of lead portions (78) to form a pair of transmission lines, each transmission line having a characteristic impedance that tends to vary with distance along the path of the electron beam due to a flared spacing between the output portions of the deflection members. Pitch compensation including different pitches for the first and second deflection members increases and maintains substantially uniform the characteristic impedance of each transmission line to prevent reflection of the deflection signal back toward the input end of the line.

Abstract: A recording material, comprising a hydrophobic substrate material with a polymeric coating, has excellent receptivity for inks that do not normally wet hydrophobic substrates. The substrate material is coated with a mixture of polyvinylpyrrolidone and a compatible matrix-forming polymer. The matrix-forming polymer is a material, such as gelatin or polyvinyl alcohol, that is swellable by water and insoluble at room temperature but soluble at elevated temperatures. A transparent base sheet, such as cellulose acetate or polyethylene terephthalate, can be coated with the mixture of polymers to provide a sheet material which can be used in ink jet printers and in pen-type graphics recorders, operating at normal speeds, to record large color-filled areas without puddling, running, or wetness and with high color density and excellent resolution.

Abstract: A cathode and grid assembly includes a first grid of small diameter secured to a planar inner surface of a ceramic means and over a central opening in the ceramic means and a second grid having a first planar section secured to a planar outer surface of the ceramic means, a second planar section positioned within the central opening and a frustum of a cone section interconnecting the first and second planar sections with the frustum of a cone section extending along a frustum of a cone outer surface of the ceramic means.

Abstract: A circuit is provided for encoding digital data to be recorded on high-density magnetic storage media. The circuit converts serial data to modified phase modulation encoded serial data with time encoding or write precompensation.

Abstract: This application discloses a linear class B transconductance power amplifier suited for use in driving an inductive load, such as a convergence control coil for a color television receiver or video monitor. A preferred form of the amplifier includes a first pair of transistors having their emitters connected together and to a reference potential, their collectors being connected together and to a voltage source; and a second pair of transistors connected to the bases of the first pair of transistors and connected together in the form of a differential amplifier. The amplifier circuit operates as a noninverting operational amplifier when an input voltage has a positive polarity, and it operates as an inverting operational amplifier when the input voltage has a negative polarity.