Abstract: A serial digital video data analyzer combines a co-processor capable of handling the serial digital video data stream bit rate with a microprocessor operating at a slower bit rate. The co-processor includes a video feature detection/decision module that identifies specified errors or features from the serial digital video data stream and freezes the portion of the serial digital video data stream around such feature/error in a video data store. The co-processor may also insert a cursor into the serial digital video data stream prior to display on a monitor to indicate the position of indicated errors. The acquired serial digital video data is transferred to the microprocessor for an initial determination as to whether further processing is required.

Abstract: An ink-jet printer that prints using an interlace ratio of higher than 2:1. The print head has an internozzle spacing of N, while the interlace ratio n:1 is selected so that n is an integer divisor of N+2 or N+4 or is equal to N+1. Multiple interlaced images can be "stitched" together by printing a first interlaced image, moving the print head and printing a second interlaced image such that the head of the second image overlaps with the tail of the first interlaced image.

Abstract: A cable loss simulator for a serial digital signal source adapts a constant resistance, bridged-T passive network to simulate the frequency-loss characteristics of a reference coaxial cable. The cable loss simulator is selectively coupled into the output path of the serial digital signal source to simulate the serial digital signal after transmission through the reference coaxial cable. The cable loss simulator has a resistive input section for impedance matching with the serial digital signal source and a bridged-T section with multiple breakpoints to simulate the frequency-loss characteristic of the reference coaxial cable.

Abstract: A dynamically paged non-volatile random access video store has a random access memory integrated with a disk drive. The random access memory provides realtime access for recording and playing back video from and to a video source. The disk drive provides a non-volatile backup for the random access memory by transferring data between the disk drive and random access memory automatically, or by command, on a non-realtime basis. The video data accesses and transfers are handled by a microprocessor that interfaces with a controller by which an operator inputs instructions. Multiple channels are accommodated via a channel interface, also controlled by the microprocessor, between external video devices and the random access memory. The disk drive stores a plurality of pages of video data, each page corresponding to the capacity of the random access memory.

Abstract: An in-service cable length and source signal level measurement system uses a simple, zero-IF superheterodyne receiver tuned to only two reference frequencies to generate samples of a serial digital signal at each of the two frequencies. The samples at the two frequencies are input to a processor that calculates the cable length and source signal level as a function of the samples so obtained and cable dependent constants. The samples in units of decibels are subtracted to obtain a loss differential between the samples at the two reference frequencies, and then scaled by a cable dependent scale factor to obtain the length of the cable independent of source signal level and temperature. The source signal level is extrapolated from the loss differential and one of the samples based upon a nominal source amplitude and the cable dependent constants.

Abstract: A switchable color filter (11) includes three polarizing filters (12, 14, and 16) and two zero to substantially half-wave optical retarders (36 and 38) and is incorporated in a field sequential display system (10) to provide output states of light of three different colors to form an image in full color. Each one of four preferred embodiments (11, 11a, 11b, and 11c) of the switchable color filter provides the output states of three colors. The third and fourth preferred embodiments (11b and 11c) provide a fourth additional output state of, respectively, white light and light of a color which is a combination of two of the other output state colors. The optical retarders comprise nematic liquid crystal cells (100) having fast relaxation times to operate the display system at video rates.

Abstract: Chrominance resampling for color images to produce an upsampled chrominance signal from a subsampled chrominance signal uses luminance to detect edges in the color image. The detection of edges produces an Index signal which is used to select a particular one of a plurality of lowpass filters for filtering a chrominance signal expanded from the subsampled chrominance signal. For interlaced video signals a field/frame decision is made based upon relative motion between the fields of each frame, which decision is input to the filter selection process. The resulting chrominance samples in the upsampled chrominance signal are offset to co-site the samples with the corresponding luminance samples at the output.

Abstract: A digital test signal generator includes the ability to adjust the SCH phase of the output test signal. A color frame reset pulse is generated at the beginning of each color frame of the output test signal. The color frame reset pulse is input to a direct digital signal synthesizer together with an SCH phase adjust signal to initialize the synthesizer with an SCH phase offset at the beginning of each color frame. By varying the amount of the SCH phase offset, the SCH phase in the output test signal is varied.

Abstract: A computer printer having a frame contained within a housing, a media transport and printing mechanism attached to the frame within the housing is provided with at least one debris shield positioned above the printing mechanism to protect it from falling debris. The at least one debris shield may be positioned below an air flow path generated by printer ventilation, and the printer may employ a transfer surface on which an image is generated prior to transfer to a media sheet, and above which the debris shield is positioned. Stripper fingers strip the media sheet from the transfer surface and webs between the stripper fingers form an air flow barrier to prevent debris transmission through gaps between the fingers.

Abstract: A multimode optical time domain reflectometer has first and second wavelength optical transmitters for launching optical pulses into a fiber under test and optical receivers responsive to the respective wavelengths for converting the optical return signals from the test filer into electrical signals for acquiring waveform data representative of the optical return signals at the respective wavelengths. A processor receives the waveform data and determines a difference in fiber slopes between the optical return signal at the respective wavelengths and adds the fiber slope difference to the waveform data of the second optical return signal for producing composite waveform data having a uniform fiber slope for the waveform data acquired at the first and second wavelengths. A multimode optical time domain reflectometer of this design provides improved two point resolution for 1310 nm testing of multimode optical fiber.

Abstract: A plasma-addressed electro-optic display device having a layer of electro-optic material, data electrodes coupled to the electro-optic layer and adapted to receive data voltages for activating portions of the electro-optic layer, and a plurality of plasma channels extending generally transverse to the data electrodes for selectively switching on the electro-optic portions. The plasma channels each contain spaced elongated cathode and anode plasma electrodes and an ionizable gas filling. To improve performance, reliability and lifetime of the device, at least the cathode electrodes have surface portions of a negative electron affinity material. Preferably, the negative electron affinity material is a film of conductive or semiconductive diamond, diamond-like carbon, or aluminum nitride.

Abstract: Smooth vertical movement of a graphics image on a raster display is performed via color palette manipulation at any speed. A color look-up table has a color palette position for each color within the graphics image plus unassigned color palette positions that are assigned to pixels on the top of horizontal color edges of the graphics image. During movement of the graphics image the color values of the assigned color palette positions are updated each display cycle as a function of a desired rate of vertical movement of the graphics image.

Abstract: A method of printing an image onto a substrate includes the steps of determining a difference in intended color intensity between a first pixel and a second pixel; adjusting the intended color intensity of the second pixel based on the determined difference; and depositing a colorant onto the substrate at the first pixel and at the second pixel at the adjusted intended intensity, so as to enhance the appearance of the image on the substrate. The current system has particular utility in enhancing the appearance of fine images such as one pixel wide, vertical and diagonal lines in a printing system which utilizes printhead heating elements that are larger in the vertical direction than in the horizontal direction.

Abstract: A non-erasable ink-jet composition that is the admixture of (1) an aqueous colored polyurethane dispersion that is the reaction product of (a) a colored urethane prepolymer that is the catalyzed reaction product of at least one polyol; at least one polyisocyanate; at least one internal surfactant; and at least one reactive colorant; wherein the ratio of internal surfactant to polyol and the ratio of NCO groups to total OH groups are predetermined stoichiometric equivalent molar ratios; (b) at least one neutralizing agent; (c) a first aqueous dispersing medium; and (d) at least one chain extender; (2) a second aqueous medium; and (3) at least one humectant; wherein the ink composition has a jettable viscosity from about 1 to about 20 centipoise at about 10.degree. C. to about 45.degree. C.

Abstract: A current probe (10) measures a signal current flowing in a conductor (12), which produces a signal flux (14) proportional to the signal current. The probe includes a pair of probe arms (16, 18) that straddle the conductor, a flux shunt (20), a pair of flux diverting arms (22, 24), and a flux link (26). A Hall-effect device (28) senses the amount of flux flowing in the flux shunt. A major portion of the signal flux flows in a preferential path (30) through the flux shunt while a minor portion flows in a flux diverting path (32). The ratio of the amount of the signal flux flowing in the preferential flux path to the diverting path depends on the reluctance in each path, which is determined by air gaps (27, 34). The Hall-effect device drives a current source (40) that provides a diverter current through a pair of flux diverting coils (42, 44) that are wound around flux diverting arms (22, 24) of the current probe.

Abstract: A digital picture manipulator processes a video image signal according to a transform function and outputs both a transformed vide image signal and a transform function information signal. A compressed video encoder uses the transform function information signal in simplifying its search algorithms to generate motion vectors to compress the transformed video image signal to produce a compressed video image signal which includes the generated motion vectors. The compressed video image signal may be transmitted to a receiver, where it is decoded using the motion vectors and displayed. The compressed video image signal also may be subsequently decoded for processing by a subsequent digital picture manipulator. The motion vectors used by the decoder together with the transform function information signal from the subsequent digital picture manipulator are combined in a buffer/motion estimator to produce a modified transform function information signal for a subsequent compressed video encoder.

Abstract: A plasma-addressed electro-optic display device comprising a layer of electro-optic material, data electrodes coupled to the electro-optic layer and adapted to receive data voltages for activating portions of the electro-optic layer, and a plurality of plasma channels extending generally transverse to the data electrodes for selectively switching on said electro-optic portions. The plasma channels each comprise spaced elongated cathode and anode plasma electrodes and an ionizable gas filling. To improve performance and increase the effective aperture and provide a stable discharge, the channels are configured with a substantially flat bottom surface portion and curved side wall surface portions on which the electrodes are deposited such that the spacing between the electrodes is increased and the electrode surfaces form an angle of the order of 90.degree..

Abstract: A cascaded anti-aliasing filter control circuit for sampled images has a plurality of video effects modules coupled in a chain,. each module performing a particular transform of a cascaded video effect. An input module has as inputs constants for the particular transform and a pixel address signal, and provides as outputs a new pixel address signal and a set of partial derivative signals. The new pixel address signal is input to a next module in the chain as the pixel address signal, and the set of partial derivative signals are input to a matrix multiplier. A set of partial derivative signals from the next module also are input to the matrix multiplier to produce an intermediate set of partial derivative signals.

Abstract: A plasma addressed liquid crystal display panel comprises a channel substrate having plasma channels in its upper surface thereof and an upper substrate over the upper surface of the channel substrate. A first polarizer is disposed over the upper surface of the channel substrate and transmits only light that is polarized in a first state. An electro-optic layer extends over the first polarizer and has a first condition in which it transmits light that is polarized in the first state without changing the state of polarization and a second condition in which it converts light that is polarized in the first state to a second state of polarization that is orthogonal to the first state. A second polarizer is over the electro-optic layer and transmits only light that is polarized in the second state.

Abstract: A media preheater positioned in the media path of a printer and having a fixed heater and a movable plate array biased toward the heater such that printing media passing between the heater and the plate array is compressed therebetween and heated. The preheater may be positioned upstream of a print head and downstream of a media advancing mechanism in the media path. More than one plate may be provided in the plate array to accommodate non-planarity of the heater or the printing medium. The plate array may be a thermally massive element that contacts the heater when no media is present, thereby permitting the medium to be heated from both sides.