Abstract: A method and apparatus for cutting simultaneously a plurality of glass fibers at an uncoated end portion so as to provide smooth mirror planar cut surfaces. The method of the present invention comprises the steps of removably securing each of the fibers on either side of a cutting point, placing each of the secured fibers on a resilient material provided in the region of the cutting point, scoring the outer surface of each of the fibers at the cutting point, and arcuately bending each of the fibers between the secured portions so as to impart a tension along the axial direction of each of the fibers, whereby the cutting occurs at the cutting point. Two embodiments of the apparatus of the present invention which perform the cutting operation in accordance with the method of the present invention are disclosed.

Abstract: A curve generator for generating a smooth curve with a pair of circular arcs between the two given points P.sub.1 and P.sub.2 on the condition that the generated curve is tangent with the given tangent lines M.sub.1 and M.sub.2 at said points P.sub.1 and P.sub.2, comprises means for defining the coordinates of the point Q of the connection of said pair of arcs on the locus satisfying the formula.angle.P.sub.1 QP.sub.2 =.pi.-1/2(.theta..sub.1 +.theta..sub.2)where .theta..sub.1 and .theta..sub.2 are angles between the line P.sub.1 P.sub.2 and the tangent lines M.sub.1 and M.sub.2 respectively. Either the major arc or minor arc between the points P.sub.1 and Q, and between the points Q and P.sub.2, that is to say, the revolutional direction of each arc is selected. Thus, a pair of arcs P.sub.1 Q and QP.sub.2 connect the two given points P.sub.1 and P.sub.2 smoothly.

Abstract: In a telephone exchange system comprising a time division exchange system and space division concentrators connected to said exchange system with a PCM lines, said concentrators are controlled by said exchange system, thus those volume of hardware in the concentrators can be considerably reduced. Said concentrator comprises a space division switching network having self-latched electronic contacts, which are controlled by a periodical drive pulse from a cyclic readout type memory.

Abstract: Like a conventional time division multiplex communication device, a device according to this invention comprises first terminals, a switching matrix, transducers or C/E buffers, control circuits, and second terminals. The first and second terminals are for low-speed and high-speed signal sequences. The control circuits are connected to the second terminals. In contrast to the conventional one, the transducers are connected to the respective first terminals, with the switching matrix interposed between the transducers and the control circuits and rendered capable of dealing with the high-speed signal sequences, among others, rather than the low-speed ones as in the conventional device. The devices are particularly useful in earth stations of TDMA satellite communication to which multi-transponder operation is applied, although useful also in carrying out conversion between low-frequency analog signal or PAM signal sequences and PAM signal sequences of a higher rate.

Abstract: A semiconductor switching element comprised by a high resistivity polycrystalline silicon resistor whose resistance irreversibly decreases to a small value at a threshold voltage upon the voltage across the resistor reaching the threshold voltage. A semiconductor memory device is constituted by using the switching element as a memory cell and a semiconductor gate element for controlling the current flowing through the semiconductor switching element.

Abstract: In single transverse mode semiconductor lasers, a semiconductor laser which comprises an optical confinement semiconductor layer having a refractive index of n.sub.3, an active layer of an optical waveguide having a refractive index of n.sub.1 and formed on said semiconductor layer, a buffer layer having a refractive index of n.sub.2 and formed on said active layer, a mode controlling striped semiconductor layer having a refractive index of n.sub.6 and formed on said buffer layer and opposing contacts, and is controllable in the transverse mode in the relations ofn.sub.6 .ltoreq.n.sub.2 <n.sub.1 and n.sub.3 <n.sub.1.

Abstract: The differential detection system comprises a demodulator for a modulated carrier transmission system for binary signals, in which a symbol detected from the phase difference between the received signal delayed by one signaling interval and the signal received in the present signaling interval is converted into data and a symbol detected from the phase difference between the received signal delayed by two signaling intervals and a signal received in the present signaling interval is converted into parity. The data and the parity are applied to a decoder for a rate 1/2 single error correcting self-orthogonal convolutional code effecting demodulation with non-redundant error correction. The correction system is also applicable to demodulate a carrier wave modulated by m (an integer) level digital data.

Abstract: Inverted frustum shaped polycrystalline semiconductor layers are formed on the emitter and collector regions provided on one surface of a semiconductor substrate, and conductor layers are applied on the upper surfaces of the polycrystalline semiconductor surfaces to form emitter and collector electrodes thus providing a bipolar transistor for the integrated circuit device.

Abstract: At the start of operation, a floating magnetic head is brought into contact with the surface of a magnetic disk and the magnetic disk is then rotated to float the magnetic head off the magnetic disk surface. At the end of operation, the floating magnetic head is drawn away from the magnetic disk surface of the rotating magnetic disk and, after the lapse of a certain period of time, the magnetic disk is stopped. This prevents the floating magnetic head from sticking to the magnetic disk owing to dew condensation, permits easy miniaturization of the floating space and provides for increased recording density.

Abstract: A frequency shift receiver for periodically receiving frequency shift (FS) signals while cyclically turning on and off a power supply for a preceding section of the receiver. An output from the discriminator is turned on and off in synchronism with the turning on and off of the power supply to prevent noise even when a frequency difference exists between the transmitter and receiver.

Abstract: An injection-locked ultra-high frequency solid-state oscillator employs an injection locking method in which an ultra-high frequency output power from a solid-state oscillator is stabilized by injecting an output signal from another stable oscillator. The signal injected into the solid-state oscillator has an optional frequency low enough as compared to that of the output power from the solid-state oscillator and is supplied through a bias supplying circuit or the like. Injection of such low-frequency signal produces sideband waves around the oscillation-wave from the solid-state oscillator while one of such sideband waves is trapped by a high-Q cavity resonator provided in the vicinity of a solid-state oscillating element of the solid state oscillator. The oscillation wave from the solid-state oscillator becomes low noise with the sideband wave trapped, and the frequency of the oscillation wave from the solid-state oscillator is made variable in obedience to the variation of the injection signal frequency.