Abstract: In the generation of NTSC color television signals, the luminance signal and the color difference signals are pre-filtered along the vertical picture axis. Full bandwidth luminance is pre-filtered by combining, with appropriate coefficients, signals from three adjacent television lines, and, additionally, a vertical detail signal is generated by combining the same three adjacent television lines, with difference coefficients, and low pass filtering the resultant signal. A desired adjustable level of the vertical detail signal is added back into the pre-filtered full bandwidth luminance signal to partially or fully cancel the effect at the lower frequencies of pre-filtering the luminance signal. Time multiplexed color difference signals at baseband are prefiltered by combining with appropriate coefficients, the signals from three adjacent television lines. The prefiltering operation is translated to the conventional NTSC chrominance band by the color modulation process.

Abstract: A decoder for use in an FM stereo broadcasting system in which the usual difference signal S and a compressed version S' of the difference signal are transmitted, automatically selects on a continuous basis for de-matrixing with the received sum signal M either an attenuated signal S' or the usual difference signal S based on the protocol that the attenuated signal S' is always selected unless the usual difference signal S is higher in level than a predetermined threshold potential related to the signal level at the knee of the expansion characteristic. The decoder eliminates the need for the relatively expensive analog variable gain amplifier used in prior art decoders and is less sensitive to time constant errors and errors due to multipath distortions.

Abstract: The high frequencies of the red, blue and green color television signals, with appropriate individual gain levels, are combined in a mixer having non-additive and additive characteristics, with the standard high frequency luminance signal to obtain a correction signal that is the greatest of the four when all have the same polarity, or in the event any of the four signals has opposite polarity with the others a correction signal that is equal to a linear combination of the two opposite polarity, highest level signals. This correction signal is used to compensate for the violation of the constant luminance principle of a luminance signal that was generated by linear matrixing of gamma corrected color signals. The compensation signal is combined with the luminance signal using a mixer similar to that used to generate the correction signal.

Abstract: A scrub pad, particularly suitable for medical uses, comprises a flattened laminate consisting of an initially compressed-in-thickness sheet of cellulose sponge material which upon absorption of washing fluids expands in thickness to approximately six times its original compressed thickness to which is bonded a sheet of mildly abrasive non-woven fabric formed of randomly oriented spray bonded synthetic fibers. In one embodiment the sponge and fabric layers are bonded together by a non-toxic heat- and pressure-sensitive acrylic resin. In another, presently preferred, embodiment the layers are joined by a cured formulation comprising selected proportions of a water activated polyurethane gel, an aqueous solution of a liquid detergent and crystalline iodine which, when wetted, releases the antiseptic detergent while retaining the bond between the sponge and fabric.

Abstract: An FM stereophonic broadcasting system incorporating companding of the difference signal in which the broadcast signal includes both the usual difference signal and a compressed version of the difference signal which utilizes, in the transmitter, a circuit for simultaneously compressing the difference signal according to a desired characteristic and modulating the compressed difference signal onto a carrier and, in the receiver, essentially the same circuit for simultaneously demodulating and expanding an incoming compressed difference signal. Simultaneous compression/modulation is achieved by multiplying the difference signal, the carrier signal and a gain control signal, preferably derived from the output signal from the multiplier, for determining the compression characteristic, thereby producing at the output of the multiplier the carrier modulated with the difference signal compressed according to a desired characteristic.

Abstract: In the receiver of an FM stereo broadcasting system which transmits both the usual stereo difference signal S and a compressed version S' of the difference signal compressed according to a compression characteristic such that signals in a lower portion of the audio frequency spectrum are not compressed and signals having frequencies above said portion are compressed, according to a desired characteristic, instead of complementarily expanding the compressed difference signal, only those signal frequencies that have been compressed at the transmitter are expanded.

Abstract: The compatibility of an FM stereophonic broadcasting system incorporating companding of the difference signal, in which both the usual difference signal and a compressed version of the difference signal are transmitted, with conventional FM receivers is improved by minimizing crosstalk from the compressed difference signal to the usual difference signal that sometimes occurs in conventional FM stereo receivers, particularly when the multiplex signal is received under multipath propagation conditions.

Abstract: To counter the effects of multipath on the signal received at the receiver of an FM stereophonic broadcasting system utilizing companding of the stereo difference signal, the normal operation of the expander embodied in the receiver is automatically modified in response to detection of multipath so as to minimize such effects and thereby improve the quality of the reproduced signal. In the preferred embodiment, a substantially fixed or steady control voltage replaces the normal dynamically varying control signal for the variable gain element of the expander during occurrences of multipath disturbances in excess of a predetermined severity. Another aspect of this embodiment is that a D.C. correction voltage having an amplitude proportional to the severity of the detected disturbances is combined with the fixed control voltage for the variable gain element in a manner to reduce the gain of the element thereby to further reduce the effect of the disturbance.

Abstract: A fixator for externally anchoring broken bones including a pair of generally planar members each having a plurality of openings adapted to receive a respective group of bone pins inserted in respective pieces of bone. The pins are clamped to the planar members with respective headed screws, and the members are held in adjustable end-to-end relationship by a lead screw anchored at one end in one of the members and engaging a threaded bore in the other member. In an embodiment useful for the treatment of comminuted displaced fractures of the distal radius and ulna, the said one member consists of two articulated sections arranged for angular and rotational adjustment.

Abstract: A method is provided for depositing on a substrate a layer of fine-grained copper especially adapted for the making of masters for optical information storage discs, comprising the steps of placing a substrate in an electroplating bath comprising from about 180 to about 220 grams/liter of copper sulfate, from about 40 to about 80 grams/liter of sulfuric acid, from about 30 to about 60 ppm of chloride ion, from about 1.0 to about 15 grams/liter of a polyether having a molecular weight from about 4,000 to about 10,000, from about 1.0 to about 100 milligrams/liter of a sulfonated, sulfurized benzene compound, and from about 3.5 to about 30 milligrams/liter of 1-lower alkyl-2-mercapto imidazole; and passing electric current through the bath to deposit copper on the substrate. Also disclosed is a method of using high performance liquid chromatography techniques to quantitatively measure 1-lower alkyl-2-mercapto imidazole concentration and to control the same.

Abstract: Methods and apparatus for solving the problem of non-uniform phosphor aging of the screen of a dual mode television receiver having the capability of displaying the picture image in two different aspect ratios, for example, 4:3 and 5:3. In one embodiment, the entire screen is illuminated during display of a 4:3 aspect ratio image on the central area of the screen so as to effect uniformity of aging over the entire screen. Alternatively, the areas at either side of the central 4:3 aspect ratio image area are not illuminated during display of 4:3 aspect ratio images but are, instead, post-aged following a period of display of such images. Another solution is to electrically compensate for the faster aging of the central 4:3 aspect ratio are of the screen when viewing 5:3 aspect ratio pictures.

Abstract: A saw blade adapted for attachment to a power operated surgical saw having teeth disposed along at least a portion of its periphery and having a centrally located saw connector receiving opening and at least one elongated slot disposed between the central opening and the cutting teeth. A cutting depth stop is releasably secured to one side of the blade and extends perpendicularly outwardly therefrom to be movable to desired adjusted positions along the length of the elongated slot. Adjustment of the position of the stop can be performed without tools and even when the saw blade is hot.

Abstract: A stereophonic electronic organ system having two electrical-acoustic channels each including a loudspeaker separated from the other, note generating means for producing for each note in a musical range two time-displaced electrical signals of substantially the same frequency corresponding to the note, and means for coupling one of the two signals for each note to one of the channels and means for coupling the other of the two signals to the other of the two channels. The two time-displaced signals for each note may be produced by providing two digital tone generators for each note and time-displacing one note from the other.

Abstract: Apparatus operable without need for an external power source for conveniently interconnecting data communication equipment (DCE), such as a modem, and multiple data terminal equipments (DTE), such as terminals and/or printers, which each have an interface conforming to a serial data communications standard, for permitting access to the DCE of any of the DTEs that may be connected to the apparatus. In the preferred embodiment, intended for the interconnection of interfaces conforming to the E.I.A. RS-232-C standard, a circuit interconnecting the data leads of a multiplicity of pluggable cable connectors supported on a chassis includes a transistor connected to be powered by input data signals from the DTEs and to operate as a switch under certain signal conditions and to be effectively removed from the circuit under other signal conditions.

Abstract: A television system for broadcasting high definition television on two channels of a direct broadcast satellite, a first of which carries a compatible 525-line picture. A second channel carries an augmentation signal, which in conjunction with the signal from the first channel, produces at a receiver tuned to both channels a 1050-line high definition television picture with a 5:3 aspect ratio. Time multiplex component signals and processing are employed, and high fidelity sound is provided by digital audio signals transmitted in time sequence with the video. There may be as many as five sound channels so as to provide three-channel stereophonic audio and various combinations of data and sound channels.

Abstract: A digital tone generator for a keyboard electronic musical instrument is described. The generator is of the waveshape memory type and repetitively interpolates between successive stored sample points thereby to effectively multiply the number of samples representing the waveshape so as to produce an output tone signal having reduced quantization error. Envelope errors are minimized by using cascade-connected multiplying digital-to-analog converters for multiplying the waveshapes derived from the interpolation with digital signals representative of an envelope waveshape. The system also includes a novel modification of a known multiplying digital-to-analog converter which greatly increases its speed of operation and makes possible the generation of clean output tone signals at the extremely high bit rates required to accomplish the interpolation.

Abstract: A stereophonic broadcasting system incorporating companding of the difference signal in which both the usual difference signal and a compressed version of the difference signal are transmitted to one or more remote receivers. At the receiver the usual, unchanged, difference signal is used as a reference signal for controlling the expansion of the compressed difference signal so as to cause the amplitude of the companded difference to equal the level of the usual difference signal. Thus, the expander is adaptive to any compression characteristic that might be employed at the transmitter. Further, the availability of the usual uncompressed difference signal at the receiver enables the adaptive decoding of dynamic parameters of the received signal, such as frequency response and attack and recovery times, so that all of the parameters of the original signal can be restored automatically.

Abstract: A stereophonic broadcasting system incorporating companding of the difference signal in which both the usual difference signal and a compressed version of the difference signal are transmitted to one or more remote receivers. At the receiver the usual difference signal and the compressed difference signal are combined and the resulting signal then expanded to obtain a noise-reduced difference signal for matrixing with the sum signal to obtain the original left and right signals. Utilizing both difference signals increases the effective level of the received difference signal by 6 dB, whereas the noise is increased only 3 dB, for a net improvement of 3 dB in signal-to-noise ratio. Utilization of both difference signals at the receiver also permits compression of the difference signal according to any desired compression law.

Abstract: A system for generating audible information from a sound track printed on paper by conventional printing techniques, the sound track consisting of a multiplicity of closely-spaced parallel sound track segments which are curved in a manual scanning direction and oriented generally transverse the manual scanning direction. Also provided is an optical scanner adapted to be manually moved along the sound track in the manual scanning direction, the scanner including means for automatically and continuously sequentially scanning the segments longitudinally to produce electrical signals representative of sound information contained in the sound track, and means for converting the electrical signals into audible sound.

Abstract: Perforated closed cell polyvinyl chloride foam padding material useful with an immobilizing orthopedic cast, said material being capable of transporting moisture along the surface thereof in contact with the human skin and of passing moisture such as water and perspiration from the human skin therethrough by vapor transmission, and being conformable and elastic in the longitudinal direction of the padding material.