Abstract: An in-service composite triple beats (CTB) measurement system for a cable television (CATV) system isolates and measures weak composite triple beat components in the presence of a visual carrier modulated with program material for selected channels of the CATV system. Each channel is demodulated and digitized in a frequency bandwidth about the visual carrier for the channel (the CTB frequency range). The digitized video is sampled during the vertical interval, and corresponding samples from consecutive frames are differenced, squared and accumulated to produce a CTB value, which may be scaled and corrected for noise. Noise correction is achieved by performing the same measurement, but digitizing in a frequency bandwidth offset from the CTB frequency range. The difference between the two measurements provides a corrected CTB value.

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: Block matching for picture motion estimation uses offset quantized pixel values. The pixels of a reference block from a first frame of a video picture sequence are offset quantized to produce a pair of offset quantized reference pixel signals. The pixels of a search area from a next frame of the video picture sequence, corresponding to a current position of the reference block relative to the search area, the search area being larger than the reference block, are quantized to produce a quantized search pixel signal. The quantized search pixel signal is compared with each of the offset quantized reference pixel signals on a pixel by pixel basis to determine whether absolute equality exists between the respective pairs of pixel signals. The comparison results are combined so that for each quantized pixel of the search block that has absolute equality with either offset quantized reference pixel signal, a tally count is incremented.

Abstract: A memory element for multiple bit storage uses a plurality of Josephson junction devices coupled in parallel between a ground plane and a superconductive line. A gate current is directly coupled to the superconductive line at a midpoint, and a control current is magnetically coupled to the superconductive line along its length. The current trajectory of the gate and control currents from an initial value to a quiescent point in the threshold curve traces determines the states of the modes. All the modes have a stable operating point at the quiescent point. The control current in the absence of the gate current is used to maintain the memory element at the quiescent point, and the gate current is used to momentarily transition none, one or more of the Josephson junction devices to a voltage state to determine the states of the modes at the quiescent point via appropriate Josephson sensors.

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: A photocurable polymer precursor added to a liquid crystal material polymerizes to form a mixture that significantly lowers the threshold and saturation voltages of a standard twisted nematic cell. The performance characteristics of the resulting display device resembles those of a device with a very high pretilt, thereby providing an economical method of fabricating liquid crystal cells of a type that require a high pretilt alignment. The presence of the polymer substantially reduces adverse ion-related effects such as optical droop and charge retention in the liquid crystal display device.

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: An alignment apparatus for determining angular coordinates for offset and intersecting optical fibers in a mechanical optical switch has an analytical apparatus for imaging the end faces of the ferrules containing the opposing optical fibers of the switch for determining the respective axes of rotation of the mounting members, the locations of the optical fibers in the respective mounting members and coordinates of the optical fibers relative to the axis of rotation of the respective mounting members, the location of at least one reference point within one of the mounting members, and the relative angular coordinates of intersecting points between each of the closed curves of the plurality of optical fibers within the second mounting member and the closed curve of the first optical fiber as a function of the offset of the first and second mounting members and the reference point.

Abstract: An improved small computer systems interface multiplexer (SCSI Mux II) provides for coupling of a computer on a local bus with shared peripheral devices on a global bus. The SCSI Mux II is accessed by a pseudo-operation code that includes two local bus identifiers as the identifier for the SCSI Mux II. Once the SCSI Mux II is identified, the computer accesses the SCSI Mux II as a local bus peripheral device and the SCSI Mux II couples the local bus to the global bus by translating the target peripheral device identification into a global identifier to complete the transfer between the computer and the designated shared peripheral device.

Abstract: A decoder using an adaptive non-separable digital filter has a correlation control circuit that generates from a composite video signal a set of filter coefficients for the non-separable digital filter. The filter coefficients are a function of a correlation angle for the image represented by the composite video signal. The non-separable digital filter, using the set of filter coefficients determined by the correlation angle, separates the composite video signal into its luminance and chrominance components. The non-separable digital filter may be approximated by a set of discrete filters having a common input, with each output being multiplied by a correlation factor, the correlation factors being the filter coefficients. The resulting multiplicands are summed to produce the separated luminance and chrominance components.

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: A video quality improvement method and apparatus for a television system recovers lost brightness information from the chrominance channels of an encoder due to processing errors, such as quantization roundoff errors, and adds it to the luminance input to the luminance channel of the encoder. Component signals from a video source are input to the encoder. The encoder provides an encoded video output signal as well as reconstructed component signals. From the encoder characteristics the processing errors for the chrominance channels are determined. The partial derivatives for each of the component signals are obtained, and the error in brightness is determined by summing the products of the errors and the corresponding chrominance partial derivatives. The luminance component signal is corrected by dividing the error in brightness by the luminance partial derivative and subtracting the result from the input luminance component signal. The corrected luminance component signal is processed by the encoder.

Abstract: A digital phase shifter produces from an input clock signal quadrature pairs of the input clock signal. The quadrature pairs are mixed and summed in response to a desired phase angle control signal to produce a phase shifted clock signal. The quadrature pairs are produced from a counter having as input a signal at four times the input clock signal frequency, with one output being a signal at the input clock signal frequency. The clock output signal is delayed one-quarter of a cycle to form a quadrature clock output signal, and the in-phase and quadrature clock output signals are converted to complementary quadrature signals. The complementary quadrature signals are input to a double 4:1 multiplexer so as to produce for any selection signal a quadrature pair of signals at the output defining one of four quadrants.

Abstract: A variable reference voltage generator provides variable voltage rails for a delay element in order to control the amount of delay of an electrical signal through the delay element. A control signal, such as an error signal from a phase locked loop, is input to a pair of operational amplifiers, one configured as a unity gain buffer and the other configured as a positive gain feedback amplifier. The one amplifier is coupled to one input of a modified Magee inverter circuit and the other amplifier is coupled to the other input of the modified Magee inverter circuit. The variable voltage rails are taken from the output buffers of the modified Magee inverter circuit. To provide a range of voltages for the variable voltage rails that approaches the power supply voltages, the two outer transistors of the modified Magee inverter circuit are converted to voltage sources so that the control signal is added to the positive power supply voltage and subtracted from the negative power supply voltage.

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 digital video recorder employing standard hard disk arrays employs a caching system to enable continuous video data to be supplied to and provided from the standard disk drives which may not be adapted for continuous data stream operation. The system is implemented as an array of disk drives and includes cache management functions for governing disk read and write operations. A predictor enables the cache to predict disk reads and disk writes and to maintain the cache based on the predictions. Redundancy enables playback in the event of failure of a drive in the array and also provides improved playback data retrieval time.

Abstract: System for automatic signal recognition and selection in a Synchronous Optical Network (Sonet) and Synchronous Digital Hierarchy (SDH) signal. The system automatically looks for signal location, signal rate, signal structure, signal payload mapping, and signal test patterns and displays the results in a matrix form. A user is allowed to select a specific channel within a specific structure, thereby setting the instrument's receiver.

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.