Abstract: The digital samples (An) representing the components in phase (X) and quadrature (Y) of data signals, are digitally integrated by the assembly comprised of multipliers (14 and 15) and an adder (16). The energy signal (Bn) which is obtained, is loaded into a register (17) so as to be provided with the energy signal obtained on the preceding sampling time. The value (Bs) of the energy signal from which the energy signal decrease rate exceeds a predetermiined value, is loaded into a register (21). Then a comparator (23) provides a binary 1 signal transmitted on the output line (25) as the energy drop signal when the value of the energy signal (Bn) has fallen below a predetermined fraction of the value (Bs) stored in register (21).

Abstract: For adaptively adjusting the gain in a modem receiver comprising two amplifiers (15, 19), the following steps are performed: for a buffer (21), a Hilbert filter (23), and an equalizer (27), a respective energy indicator (P.sub.max.sup.2, u.sub.avg.sup.2, x.sub.avg.sup.2) is generated from the signal samples in the respective delay line. Each energy indicator is compared to an associataed upper target level (4L.sub.U, 3L.sub.P, 1.19 L.sub.X), and for the equalizer also to an associated lower target level (0.84 L.sub.X). If necessary, a gain correction factor (S) initially set to 1.0 is modified to obtain an overall gain that keeps delay line energies within desired targets. Target comparisons are made so that excess energy in the buffer or Hilbert filter result in a rapid gain reduction whereas average equilizer energy is used for slow adaptations. After a gain change, all acquired samples in the delay lines are also multiplied by the correction factor (S) so that none is lost during gain acquisition.

Abstract: A holographic scanner includes a rotating glass disk carrying a plurality of scan line generating holograms, a laser light source and means for detecting reflected optical energy. The scanner is improved by adding a plurality of relatively small position-indicating holograms in alternation with the scan line generating holograms. The position-indicating holograms redirect the laser beam along desired paths on the same side of the disk as the laser. The redirected laser beam may be detected by the system photodetector or an auxiliary photodetector to provide signals indicating the current disk position. The position information can be used by a system processor to optimize scanner parameters as a function of the characteristics of the next active scan line generating hologram.

Abstract: This disclosure describes a technique for reading bar codes scanned by focussed scan lines having different focal lengths where at least one of the scan lines has a beam that is small relative to irregularities of the surface on which the label appears. The scan lines are generated using a holographic disk so as to have a predetermined focal length and focal zone. The focal zone of each generated scan line overlaps the focal point of at least one adjacent scan line. Any bar code label which might be scanned by a beam so small that it would be degraded by surface scatter noise is also scanned by a slightly larger beam. The slightly larger beam "averages out" the surface scattering noise to produce a smoother or cleaner return signal.

Abstract: An inexpensive tilt mechanism for a display terminal includes a pair of L-shaped rails at the bottom surface of the terminal. The rails define a channel extending from front to back at the bottom surface. At least one of the rails has a toothed surface. A movable support includes a pedestal attached to a base plate which can be shifted along the channel defined by the L-shaped rails. In a preferred embodiment, only one of the rails has a toothed surface while the pedestal has an attached lever which can be used to pivot the movable support about the other rail until it clears the teeth. In this disengaged position, the movable support can be shifted along the channel.

Abstract: A thin film transistor liquid crystal device with color capabilities can be fabricated using polychromatic glass. Polychromatic glass is a full-color photosensitive glass in which colored regions can be established through exposure to ultraviolet radiation either concurrently with or followed by heat treatment. To assure that colored regions in the polychromatic glass are aligned with individual pel electrodes, each driven by a thin film transistor, the pel electrodes are used as a shutter to control the exposure of the polychromatic glass to the ultraviolet radiation.

Abstract: The color filters required for a thin film transistor liquid crystal display device are provided by using polychromatic glass for either the front or rear glass panel of the device. Through a series of masking, ultraviolet exposure and heat treating steps, red, green, and blue color areas can be generated in the polychromatic glass. Each of the different colored areas is, of course, to be aligned with one of the individually-addressable pel electrodes in the device. Two embodiments are described. In the first, the polychromatic glass forms the rear glass panel of the device and serves as a substrate for the thin film transistors used to individually address pel electrodes. In an alternate embodiment, the front glass panel of device is treated to form the color filter regions.

Abstract: A fixed position optical scanner with a multi-faceted holographic disk includes circuitry for adjusting the lockout voltage as a function of the focal length of the active facet. The disk position is tracked to identify the active facet. A facet identifying signal is used to address a lockout table in processor memory. A digital value retrieved from the lockout table is converted to analog form and applied through a resistor to a voltage divider in the threshold circuit. The voltage divider scales down a white peak following voltage and compares it to a black peak following voltage. The facet-dependent lockout voltage biases the junction of the voltage divider to vary the effective lockout voltage as a function of the focal length of the currently active facet.

Abstract: A method for forming UPC or EAN bar code labels from scans of half labels or less than half labels requires that captured data be examined and classified as being either a first type of data configuration or a second type. A first type includes a given number of numeric characters delimited by both margin and center characters. A second type includes either a margin character or a center character and a given number of numeric characters. Labels are formed, where possible, by using appropriate first type data configurations. If labels cannot be formed using only first type configurations, second type configurations are examined to determine if they could represent different portions of the same region (left or right) of a label. If complementary second type configurations are found, they are merged to form a half label. The formed half label may be further merged with a complementary first type data configuration to form a complete label.

Abstract: A system is disclosed for preventing processing of duplicative coded label signals generated by a scanner lacking item detectors. The system establishes a variable lockout time as a function of operator performance. Any detected label candidate which duplicates a candidate received within the lockout time is assumed to be duplicative. Any transfer to the terminal is inhibited. Operator performance is tracked by measuring the inter-item arrival times for candidates actually transferred to the terminal. The inter-item arrival times are averaged over a given number of items. The average value is used to select a lockout time which is generally proportional to the average inter-item arrival time.

Abstract: NTSC composite color video signals captured in a freeze-frame videoconferencing system can be decomposed into luminance and chrominance components using simple digital addition and subtraction. The necessary apparatus includes a conventional color camera, an analog-to-digital converter, and a superframe buffer, organized into four field buffers. The analog signal is sampled at phase angles which are displaced at 135 degree increments. The preferred phase angles are 0, 135, 270, 45, 180, 315, 90 and 225 degrees relative to the phase of the color burst for the current scan line. Due to the reversal of the color burst phase on a frame-to-frame basis, a luminance or Y value can be obtained for each pel by adding the digital values stored in corresponding pel positions in corresponding fields (odd or even) in two successive frames of the same image. A chrominance or C value can be obtained by subtracting the same two values.

Abstract: When a byte of digital data is transmitted through a dispersive medium using frequency or wavelength division multiplexing (WDM) techniques, individual bits in the byte are normally delayed different amounts of time. This is referred to as bit skew. WDM apparatus is described along with a system for deskewing WDM data received after transit through a dispersive medium. Two bits in a given byte of data are detected. The relative times of arrival of the remaining bits in a byte are predicted using the relative delay between the two detected bits and the known frequency-related dispersion characteristics of the transmission medium. Certain bits in each received byte may be delayed using clock delay lines or registers to reduce the amount of time skew between the various bits in a byte.

Abstract: A piezoelectric touch screen assembly can be attached to mounting ears on an ordinary CRT assembly. The touch screen assembly includes a frame, a glass plate which is seated on a gasket at one surface of the frame and a plurality of piezoelectric elements which are bonded to the glass plate and are "trapped" between the CRT face and the glass plate. Studs extend outwardly from the CRT ears through openings in the frame. Coil springs are placed on the studs and are trapped by washer nuts to load the touch screen assembly toward the CRT by a predetermined amount. Grommets with a unique cross sectional configuration are mounted at the openings through the frame. The grommet is designed to provide minimal resistance to movement of the touch screen assembly toward or away from the CRT face but greater resistance to movement of the assembly in other directions.

Abstract: A method is disclosed for thresholding the luminance component of color picture elements (pels) prior to compression. The method is most effective when used with discrete color images, such as documents having areas of nominally constant color. The method uses spatial information rather than histogram information to threshold the image data. Each scan line is defined as having a series of pel runs. A pel is considered to be in a run if its luminance is within a certain range of an average luminance based on preceding pels. Each run may end in a transition region wherein the luminance of each pel differs from the luminance of the preceding pel by more than a predetermined amount. Where a transition region is found, a local threshold is set based on the average luminance of the preceding run and of the following pel. All pels in the transition region are assigned a luminance value equal either to the average luminance of the preceding run or the actual luminance of the following pel.

Abstract: A processor-assisted system helps persons with speech or hearing handicaps communicate with any telephone caller having an ordinary tone generating telephone. With minimal training, the caller can communicate with the handicapped person using a one key per letter technique for spelling out words. Received keypad sequences are decoded by the processor and the decoded message is presented on a video display or monitor. Since there are three alphabetic letters on most of the keys of a tone generating telephone, the decoding process must take into account that more than one word might have been intended by a particular keypad sequence. The decoding process retrieves all possible words and allows the handicapped person to choose the appropriate word from the context of the sentence. According to one decoding process, all words which might be represented by a particular key sequence are stored in records including the keypad sequence.

Abstract: An optical fiber connector includes a ferrule with an interior splice chamber. A fiber stub is installed in the ferrule in a factory operation with one end in the splice chamber. The ferrule also includes permanent, opposed electrodes with tips at the walls of the splice chamber. To attach the connector to an optical cable in a field operation, a predetermined length of insulation is stripped from the end of the cable and the bare fiber is inserted into the splice chamber through a bore in the ferrule. Voltage is applied across the electrodes to create a plasma arc in the splice chamber. The plasma arc melts and fuses the adjacent ends of the cable fiber and fiber stub.

Abstract: A process is described for identifying those pels in a gray scale image which are candidates for vertical filtering before the image is thresholded to binary or black/white pel values. The vertical neighbor pels of a pel below a run end point are examined to determine whether their gray scale values fall within the same range. If they do, the horizontal neighbors of the current pel are examined to see whether their gray scale values fall in different ranges. If they do, the pel is vertically filtered by adjusting its gray scale value as a function of the differences between its value and the values of its vertical neighbors. Because only selected pels are vertically filtered, the process can be carried out with a general purpose microprocessor rather than a special purpose parallel processor.

Abstract: Distributed transmission control for a TDMA system including one or more user networks. A time synchronized burst modem, one at each earth station in a system, transfers TDMA frame timing signals to an interconnected data processing machine. The interconnected data processing machine is then capable of synchronizing information transfer to the time synchronized burst modem in accordance with the received TDMA frame timing signals. Accordingly, each network has available to it, at each data processing machine in the network, TDMA frame timing signals. Accordingly, optimizing information transfer can be effected on a network-by-network basis, wholly independent of overall system TDMA information transfer optimization.

Abstract: An optical scanner uses frequency modulation and detection techniques to produce and utilize multiple, simultaneous scan patterns in which corresponding scan lines have different focal lengths. Two or more solid state lasers are modulated at unique frequencies. The frequency modulated output beams pass through different combinations of focusing lenses and are deflected by a single beam deflecting apparatus. Light reflected from any scanned object is detected. The resulting multi-frequency signal is applied to a plurality of bandpass filters to separate the returned signal into a plurality of separately decodable signals.

Abstract: An optical scanner is improved by securing beam directing holograpic films to the transparent scanner window. The films alter the paths of beams at the window to provide scanning beams suitable for rear or side scanning of label-carrying products. A vertical scanning beam, which sweeps a path parallel to the window's leading edge, might be used to detect the approach of a product to be scanned.