Abstract: A semiconductor light amplifier having an active layer performing a light amplification function, in which the light amplification is performed intermittently by a stable clock timing synchronized with the clock timing of an input light pulse train to the active layer.

Abstract: A satellite repeater for a digital satellite communication system for use on board of satellites. Receivers are provided with respective antennas for receiving radio-frequency signals from a plurality of ground stations. A signal processing circuit switches signals received in synchronism with stable clock timings. Transmitters receive the switched outputs of the signal processing circuit to provide radio-frequency signals for transmission through respective antennas of the transmitters. Timing detectors receive the outputs of the receivers and detect the frame timings of the output signals of the receivers. Signal storage circuits are provided between respective outputs of the receivers and the signal processing circuit for storing the respective output signals of the receivers by respective amounts.

Abstract: A submarine optical fiber cable using a low-loss optical fiber as a transmission medium, which is provided with a cylindrical pressure resisting layer composed of an assembly of three equally divided long pressure resisting segments of fan-shaped sections with flat contact planes and having at least one optical fiber in an optical fiber housing space formed in the center of the assembly so as to protect the optical fiber from a high water pressure.

Abstract: A fiber for optical transmission, in which a core thereof for propagating light is formed of a single crystal of an ionic substance except positive ions having no closed cell electronic structure and positive ions of strong covalency. The ionic substance is a binary system compound, a ternary or more multi-system compound, or a solid solution between a binary system compound and a ternary or more multi-system compound.

Abstract: An optical-fiber submarine cable, in which a combination is provided by a thin, cylindrical pressure resisting sheath, and a reinforcing member of a cross section inserted by the thin, cylindrical pressure resisting sheath so as to divide the circular cross section of the pressure resisting sheath into a plurality of spaces and to have a required withstand pressure; and in which at least one low-loss optical fiber is inserted in each of the plurality of spaces. The combination can be fabricated by separately paying out the reinforcing member and the thin, cylindrical pressure resisting sheath, or by curving inwardly a sheet of tape being paid out.

Abstract: A method for coding addresses of information change picture elements each having information different from that of the immediately preceding picture element in a facsimile signal obtained by successively scanning an original picture, in which the information change picture elements are classified into deviation change points each having a high correlation to a final reference change point selected from coded information change picture elements, and new change points each having substantially no correlation to the final reference change point. The deviation change points are coded to indicate the direction and length of each deviation thereof from the corresponding final reference change point. The new change points are coded to indicate each distance thereto from the immediately preceding information change picture element.

Abstract: A facsimile signal coding system, in which a facsimile signal is divided into a plurality of scanning line groups each including a predetermined number of scanning lines. A substantially central one of the scanning lines of each group is encoded by a coding method without referring to information of a scanning line adjacent to the central scanning line. Information of the remaining lines above the central scanning line is sequentially encoded upwardly from the central scanning line using information of the just precedently encoded line as reference information. Information of the remaining lines below the central scanning line is sequentially encoded downwardly from the central scanning line using information of the just precedently encoded line as reference information.

Abstract: In a facsimile system having a carrier movable linearly in both directions with a read-head and a write head for scanning an original paper and/or a printing paper, the movement of the carrier of the facsimile system in a receiving mode is initiated by the synchronization signal sent from another facsimile system in a transmission mode, thus the operation of the facsimile system in the receiving mode is synchronized with that in the transmission mode, on a start-stop basis. Said synchronization signal is sent from the transmission station to the receiving station for every both way trip of the carrier.

Abstract: A facsimile signal transmission system, in which a coder is provided for coding an input facsimile signal for each information block of picture elements on a predetermined number of scanning lines. A counter is provided for counting the number of bits of each coded output corresponding to the picture elements of the predetermined number of scanning lines. Dummy codes are added to the coded output of the coder to increase the number of bits of the coded output to be larger than a reference bit number predetermined in consideration of the subscanning time at the receiving side in a case where the count result of the counter is smaller than the reference bit number.

Abstract: A method for coding a facsimile signal, in which addresses of information change picture elements each having information different from the immediately preceding picture element on the same scanning line of a facsimile signal are firstly coded for each scanning line to develop a first coded output. In response to the first coded output, the relative distance of each of the information change picture elements to a final reference change point which is selected from information change picture elements on the scanning line including the instant information change picture element to be coded or on at least one immediately preceding scanning line is secondly coded to develop a second coded output. The number of successive information change picture elements having the zero value of the relative distance or the order number of information change picture elements are thirdly coded for each scanning line in response to the second coded output.

Abstract: A facsimile signal coding method, in which information change picture elements are classified into two kinds of change points according to the information change directions. In case of the information change picture element having an information change from white to black, the relative distance between an instant information change picture element and a reference information change picture element selected from information change picture elements on the same scanning line or at least one immediately preceding scanning line is coded. In case of the information change picture element having an information change from black to white, the distance between an instant information change picture element to be coded and the immediately preceding information change picture element is predicted on the basis of information of a run already coded, so that an error between the predicted value and the run length of the instant run is coded.

Abstract: A facsimile signal coding system for successively coding runs of black and white signals included in a facsimile signal obtained by scanning an original picture, in which the length and position on a scanning line of the runs of the black or white signal to be indicated by encoded codes are temporarily stored in a memory. Information of the run of the same state signal as an instant run of black or white signal to be coded and close to the instant run is taken out as reference run information from the memory. The length of the instant run of the black or white signal to be coded is predicted on the base of the reference run information. An error between the predicted run length and the length of the instant run of black or white signal to be coded is coded. When the error exceeds a predetermined value, the length of the instant run of the black or white signal may be coded in place of the error.

Abstract: A system for receiving an input facsimile signal sometimes added with dummy codes for each predetermined number of scanning lines by the use of a decoder for decoding the input facsimile signal for each information block of picture elements on the predetermined number of scanning lines. The number of bits of the input facsimile signal corresponding to the picture elements of the predetermined number of scanning lines is counted by a counter. When the count result of the counter is smaller than a reference bit number predetermined in consideration of the subscanning time of a receiver, the subscanning of the receiver is omitted. In this case, an operation of feeding a recording paper of the receiver may be effected.

Abstract: A signal compression system for efficient transmission of an input binary digital signal, in the form of a binary pulse signal, in which bit polarity reversal is checked after sampling for a predetermined number of bits of the sampled binary pulse signal. In a case of detection of any bit polarity reversal, the sampled binary pulse signal is sent out into a converted output pulse signal for the predetermined number of bits. In a case of non-detection of any polarity reversal, the number of bits or the number of bit blocks having no polarity reversal is coded as a coded pulse signal and sent out into the converted output pulse signal. A coded pulse signal is distinguished, the the converted output pulse signal, from the binary pulse signal by at least one flag bit.

Abstract: A system for coding information change picture elements in a facsimile signal, which is employed for coding the address of each information change picture element assuming information different from that of an immediately preceding picture element on each scanning line. A distance between the information change picture element and a final reference information change picture element selected from the information change picture elements of an immediately preceding scanning line and, if necessary, said scanning line is encoded in a manner to minimize the number of bits of each code word.

Abstract: A signal combining system employed for transmitting a plurality of pulse signals, in which if binary information of the same polarity is continuously transmitted for a period of time, in comparison with the last bit of the preceding period of time, in a main input communication circuit such as a facsimile circuit, signal combining is effected to insert therein other prestored binary information from another communication circuit. The above signal combining is performed for information blocks, each of which includes at least one sign bit for distinguishing pulse signals of the main communication circuit and another communication circuit from one another.

Abstract: A system for coding two-dimensional information of M lines and N columns, in which two-dimensional information of M lines and U columns is predetermined as a basic block. If any column information in the basic block has an information change with respect to column information immediately preceding it, information in the basic block is coded. If each column information in the basic block has no information change with respect to the column information immediately preceding it, information corresponding to the number of columns of the basic block and the number of subsequent columns having no information change is coded. Two-dimensional information obtained after the computation operation of a correlation function between an instant bit of information and an immediately preceding bit of information in at least either of the line direction and the column direction may be applied as the input of this system.

Abstract: A magnetism detecting system, in which reference magnetic fields sequentially scan many radial scanning lines obtained by dividing a plane to be detected at regular intervals of a desired angle with respect to an origin positioned at the common intersecting point of said scanning lines. At least one parametrically excited second harmonic oscillator detects the direction and magnitude of a magnetic field to be detected along each of the scanning lines. A display device is provided for scanning and displaying the plane with respect to the origin in synchronism with the scanning of each of the scanning lines. A detected output is applied to the display device when the magnetic field to be detected and the reference magnetic field coincides with each other in direction and in magnitude.

Abstract: A system for coding information change picture elements in a facsimile signal, which is employed for coding the address of each information change picture element assuming information different from that of an immediately preceding picture element on each scanning line. A distance between the information change picture element and a final reference information change picture element selected from the information change picture elements of an immediately preceding scanning line and, if necessary, said scanning line is encoded in a manner to minimize the number of bits of each code word.