Abstract: An adaptive equalization system for compensating the nonlinearities generated in a traveling-wave tube amplifier comprises an equalization circuit connected to the traveling-wave tube amplifier. The equalization circuit has a series circuit having a distortion generator for providing a high order distortion, a variable phase shifter and a variable attenuator for controlling the phase and the amplitude of the output of the distortion generator, and a delay line connected parallel to said series circuit so that the delay time in the delay line is equal to the delay time in that series circuit. A distortion detector is provided at the output of the traveling-wave tube amplifier for detecting the residual distortion in the output signal, and a distortion control circuit is provided for adjusting the variable phase shifter and the variable attenuator so that the residual distortion at the output of the traveling-wave tube amplifier becomes minimum.

Abstract: A digital multi-frequency receiver for the use in an electronic telephone exchange system for detecting MF signals (700,900, 1100, 1300, 1500 and 1700 Hz) in the CCITT No. 5 system. The digital multi-frequency receiver comprises a recursive digital filter for detecting each of the MF signals on a time divisional basis, an absolute value circuit for providing the absolute value of the output of the recursive digital filter, a comparator for comparing the output of the absolute value circuit with a variable threshold to provide the detected MF signal information, and a circuit for providing the variable threshold by selecting the maximum value from among, (i) the predetermined fixed value, (ii) the product of the value .alpha. which is less than but close to 1 and the maximum value of the variable threshold circuit in a preceding frame, and (iii) the maximum value of the output of the absolute value circuit in a present frame.

Abstract: A small printer is provided which comprises a housing, a rolled printing paper mounted in the housing, a platen along which a paper runs, a motor, and a carriage having a printing head for mosaic printing on a paper on the platen. The carriage travels along the whole width of the paper and is driven by the motor, and a paper transfer mechanism transfers the paper by one line for every traverse of the carriage. The paper transfer mechanism comprises an idler positioned beneath the path of the paper, the idler being swingable in the moving direction of the paper, and the idler having a first projection parallel to the path of the carriage at the left half of the idler and a second projection inclined to the path of the carriage at the right half thereof. The projections are engaged with the corresponding slots provided at the bottom of the carriage to ensure the swing movement of the idler is synchronized with the movement of the carriage.

Abstract: A heat pipe structure comprises a wiring substrate consisting of ceramic or silicon having a cavity in the interior on the inner surface of which is formed a wick and which contains working fluid, and radiating fins formed at the end of the substrate. Integrated circuit elements, integrated circuits or integrated circuit devices are securely inserted in holes which are formed on the surface or the back of the substrate and which communicate with the cavity so that the wick on their backs is aligned with the wick on the inner surface of the cavity for directly cooling the integrated circuit elements, the integrated circuits or the integrated circuit devices.

Abstract: A binary transversal filter which has a plurality of stages of shift registers that are driven by timing signals of a frequency which is a multiple of that of clock pulses being introduced, and a weighting circuit which weights outputs of shift registers of each of the stages, so that outputs of the weighting circuit can be synthesized. The characteristic feature of the present invention resides in the facts that NRZ signals are introduced into the shift registers, and the shift registers are driven by timing signals of a frequency which is a multiple of that of clock pulses of the NRZ signals.

Abstract: A mechanical optical switching device has a plurality of input optical fibers coupled to the input side of the mechanical switching device for receiving incoming light beam signals. Individually associated with each optical fiber is an input collimating lens which is positioned to receive the incoming light beam and to convert it into parallel light beams. Optical path-switching means, having a uniform refractive index, are disposed at the rear or output of the input lens for switching the optical paths of the collimated parallel light beams emerging from the input lens means. A plurality of output optical fibers have individually associated output lenses for focusing the parallel light beams, after they have passed through the position controlled by the optical path-switching means.

Abstract: A subreflector and reflectors in a primary radiation system, these constituting an offset dual-reflector aerial, are subjected to the so-called reflector-surface shaping. The main reflector is formed as a part of a revolutional paraboloid, and is a combination of a number of congruent reflector-segments. With such an arrangement, the manufacturing cost of a large-sized main reflector is reduced. The production error, and the aerial gain reduction and the deterioration of a wide-angle directivity due to the production error are minimized.

Abstract: A process for producing an optical fiber preform which comprises forming a particulate glass rod in which the dopant concentration gradually increases toward the center of its cross section, and gradually heating the rod starting at a temperature below the minimum collapsing point of the fine glass particles in the center of the rod in such a manner that the softening of the rod proceeds from the center outward, to thereby produce a transparent glass rod.

Abstract: The present system comprises (a) a character input unit for providing the coordinates of a plurality of points of an input character, (b) a pre-process unit for normalizing the size and the position of said input character, (c) three points approximate unit for providing three feature points for each stroke of the input character, (d) a reference pattern storage for providing the coordinates of the feature points for each stroke of the reference characters, (e) a stroke difference calculator for providing the sum p.sub.i of the length between the feature points of the k'th stroke of the input character and the feature points of the i'th stroke of the j'th reference character, (f) a storage for storing the stroke difference p.sub.i, (g) means for operating the members (e) and (f) repetitively for all the strokes of the j'th reference character, (h) means for detecting the minimum value p.sub.min among the stroke difference p.sub.

Abstract: A heat-sensitive transfer element comprising a foundation, a thermal color-developing layer provided on the front surface of the foundation and a hot-melt ink layer provided on the back surface of the foundation; the ink layer including a heat conductive material powder and a solid wax, and having a melt-transfer property a printed image to be formed on the thermal color-developing layer by the impression of a thermal head, and simultaneously the hot-melt ink being transferred to a copy sheet facing the transfer element at the hot-melt ink layer side, the duplicated image having good clarity and excellent durability being able to be prepared at a high speed on a thermal printer.

Abstract: In a digital-to-analog converter having means to convert a digital input signal into an analog signal, processing means to evaluate an error attendant upon the conversion, and memory means to store the evaluated error; a digital-to-analog converter with a compensating circuit wherein the processing means comprises a ramp voltage generator, a clock pulse generator, and counting means to count clock pulses of the generator and to deliver the error on the basis of the count value of the clock pulses at each time when the ramp voltage exceeds the output of the conversion means.

Abstract: Input logical data is sequentially divided by a data dividing circuit for each time slot into n data trains, of which each data block has an n time slot length. A clock signal which can be arbitrarily timed, is divided by a clock dividing circuit into a n clock signals which are displaced one time slot apart in phase and which occur with a period of n time slots. In a logical circuit, the divided clock signals are controlled by the divided data trains corresponding thereto, and the controlled clock signals are time multiplexed by a multiplexing circuit, whereby output data with which the input logical data has been timed by the clock signal is obtained.

Abstract: An aperture antenna having the improved phase performance of radiated co- and cross-polarization has been found. The present antenna has, at least, a horn for radiating an electro-magnetic wave, and means for focusing the electromagnetic wave. The focusing means is actually implemented by a reflector or a dielectric lens, and is designed so that the phase distribution of an electric field on an aperture plane of the focusing means has the period of .pi./2 and the maximum phase at (2m-1) .pi./8 from the reference plane of one polarized wave in the polar coordinates system on the aperture plane, where m is an integer.

Abstract: A nozzle for issuing ink liquid, a vibrator for exciting the nozzle to emit ink droplets of a given frequency, and a charging electrode for charging the ink droplets in accordance with print information are arranged within a cylinder shaped housing. One end of the cylinder shaped housing is covered by a wall having an opening at the center thereof through which charged ink droplets are propelled. A fixing plate is attached to the other end of the cylinder shaped housing for tightly securing the nozzle, the vibrator and the charging electrode within the cylinder shaped housing.

Abstract: A digital video and audio file system is provided for use in systems such as a center-to-end video communication system. In the file system, video information, such as a color television video signal, is digitized in such a manner that it is separated into a luminance (Y) signal and a carrier chrominance (C) signal and these separated components are processed by the code differential method and the variable length encoding method. The digital signal thus digitized is recorded in a digital recorder. On the other hand, audio information is digitized by the AD-PCM encoding method and recorded in the same recorder. In encoding the video and the audio information, a part of hardware is used in common for both the signals, thus saving the hardware of the file system.

Abstract: A memory circuit comprising a memory cell for storing information, constituted of semiconductor circuit elements and the associated circuit elements, and a control input section provided on the input side of the memory cell for controlling the memory cell, constituted of transistor means and current control means, wherein one of ON and OFF states is selected and also held in accordance with more than two logic input signals supplied to the control input section and no power is consumed to hold the OFF state.

Abstract: A pattern recognition system operating on an on-line basis for hand-written characters, in particular for hand-written Chinese characters comprises a character input unit for providing the coordinates of a plurality of points on the strokes of a written input character, a classification unit for classifying the input characters to the first group having equal to or less than three strokes, and the second group having equal to or more than four strokes, an approximate unit for providing a plurality of feature points to each of strokes, the number of strokes being six for each stroke in the first group of characters and three for each stroke in the second group of characters, a pattern difference calculator for providing the sum of the length between the feature points of the input character and those of the reference characters which are stored in the reference pattern storage, and a minimum difference detector for determining the minimum length among the pattern differences thus calculated.

Abstract: A multi-stage switching network comprises a plurality of unitary switch matrices each including a number of cross-point circuits each of which in turn includes a memory circuit operatively connected to the associated cross-point switches in a speech path. The plurality of the unitary switch matrices are arranged in a matrix array in which each stage of the multi-stage switching network is constituted by the unitary switch matrices arrayed in at least one column thereof and interconnected through links.

Abstract: A satellite relay system for Time Division Multiple Access (TDMA) utilizing a beam scanning technique has been found. According to the present invention a plurality of antennas each relating to the corresponding earth station have a narrow spot beam with sharp directivity. Each of the up-link bursts (a signal from an earth station to a satellite) is simply combined, and a single-channel TDMA signal is obtained. Said TDMA signal is then divided into a plurality of signals by a power divider after frequency conversion. Each of said signals is processed by a variable phase shifter, the output of which is applied to a power amplifier. A 2n-port directional coupler having n number of input terminals and n number of output terminals is provided and each of said input terminals is connected to the output of the corresponding power amplifier.

Abstract: A receiving system without antenna switching wherein signals received by two or more spaced antennas are heterodyned using local oscillation signals at frequencies spaced from each other by not less than the fundamental frequency of a modulating signal. The resultant intermediate frequency outputs are combined and detected to produce an output signal.