Abstract: An LN (Lithium Niobate) modulator outputs light Po modulated using a modulation voltage Vm. An inputted light signal average level monitor is arranged at the input of the LN modulator. Further, an outputted light signal average level monitor is arranged at the output of the LN modulator. A negative feedback circuit controls the feeding back of a bias voltage applied to the modulator from the average level of the input signal and the average level of the output signal. Further, a bias voltage limiter performs control in such a manner that the center of the voltage limiting range for the bias voltage becomes the optimum operating point. This bias voltage limiter has: a voltage limiter for limiting the operating output range of an op-amp to be a prescribed voltage range; an integrator for applying an offset voltage to and shifting the limiting voltage of the voltage limiter; and a difference monitor for monitoring the difference between a modulation voltage Vm and an offset voltage .increment.V.

Abstract: A typical booster circuit of the present invention comprises a first capacitor having first and second electrodes, a second capacitor having first and second electrodes, a switching circuit for transferring boosted potential appearing on each first electrode of the first and second capacitors to a boosting potential output node, a precharge circuit for precharging each first electrode of the first and second capacitors, a logic circuit for setting a potential level of the second electrode of the first capacitor to a first potential level and setting a potential level of the second electrode of the second capacitor to a second potential level which is higher than the first potential level, respectively upon reception of a control signal having a first state, and for setting the potential level of the second electrode of the first capacitor to the second potential level, and setting the potential level of the second electrode of the second capacitor to the first potential level, respectively upon reception of a

Abstract: A substrate is heated in a crystal growth vessel evacuated to a ultrahigh vacuum, and gases containing component elements of a crystal to be grown on the substrate are introduced into the vessel under predetermined conditions to cause successive epitaxial growth of single molecular layers, the number of growth cycles being automatically controlled. A mass analyzer is disposed opposite to the substrate in the vessel so that the progress of crystal growth can be incessantly traced and evaluated for each of the molecular layers. An etchant gas introduction nozzle extends into the vessel to make etching treatment of the surface of the substrate in the evacuated vessel prior to the crystal growth.

Abstract: A parallel multiplier consists of a systolic array of AND gates and full adders organized in stages so that each stage generates a partial product, adds it to the preceding partial products, and furnishes the sum to the next stage. A control circuit is provided that disables the outputs of each stage of the array until the operation in the particular stage is completed. The disabling of outputs reduces power consumption.

Abstract: A join operation processing system and a method of operating the system is usable in a distributed database management system including multiple local database management systems, computers employing distributed databases stored in the local database management systems, and a communication network for connecting said local database management systems and the computers. The join operation processing system can perform a join operation on a relational database. Each of the computers instructs prior computer to performing the join operation, and the database management system, managing relations associated with the join operation to read definitions so as to define said relations, reads the read definitions to thereby determine a process to process the join operation, and issues a request to the prescribed database management system to perform join operation processing based on the determination.

Abstract: To simplify both the printed circuit board connector structure itself and the circuit board connecting work, the improved circuit board connector comprises a connector body and plural roughly U-shaped spring contacts elastically housed within the connector body. Circuit boards to be connected are engageable with the board connector in card edge connection manner or in bolt-nut connection manner. The above board connector is simple in structure and in connecting operation so as to be available for an automatic mass-production assembly process line.

Abstract: A circuit for preventing a dV/dt erroneous operation of a PNPN semiconductor switch is replaced by a capacitance on the surface of a semiconductor substrate, a high resistance gate electrode. In other words, such a circuit is formed on the surface of the substrate by a slight modification of the basic design without decreasing the chip area and without isolating component elements.

Abstract: A submersible which can automatically move along the cable laid under water, has a sensor, and the information collected or gathered by said sensor is forwarded to the control unit on land through said cable. The submersible is for instance connected acoustically to said cable. The cable has a plurality of transducers at every predetermined length for sending the control signal from the cable to the submersible and receiving the information from the submersible.

Abstract: A high speed printer in which the ions produced between the high voltage impressed electrodes are modulated by an aperture board and then passed through an ink mist so as to electrically charge the ink particles whereby to print the desired letters, figures, signs, etc., on a printing paper, characterized in that a heating element is provided in the aperture board for lowering the relative humidity in said aperture board.

Abstract: An ink-jet printer which blows ink drops to the surface of the printing paper so that the contours formed by the ink drop dots are letters, numerical figures and signs. The printer includes pairs of deflection plates with the amount and timing of the deflection being controlled by synchronized digitally controlled voltages.

Abstract: An apparatus for analyzing sound ray paths of a sonar system by a hybrid computer is disclosed, wherein the sound velocity gradient g is computed by a digital computer and the ray angle .theta. and the coordinates (x, z) of the ray path are computed by an analog computer, thus, accurate and high speed analysis of the ray paths can be performed. Further, in the analog computation, the inclination of the sea bottom is taken into consideration by the presence of a reflection computer.

Abstract: A numerical control comprising an input means for reading a program, a forward-interpolating-information producing circuit, a reverse-interpolating-information producing circuit, an interpolation circuit and a control circuit for controlling the above means is provided.

Abstract: A magnetic relay having a core, coil, an armature with a pair of dielectric cards, a plurality of pairs of contact points and a contact spring, has been found. One of said dielectric cards pushes or releases the contact spring according to the electric current flowing in said coil and said pairs of contact points are closed or opened. The structure of the present relay is so simple that mass production and improvement of accuracy of the relay can be easily accomplished.

Abstract: A high speed printing apparatus in which ions produced between electrodes receiving a high voltage are passed through an ink mist so that they are deposited with the ink particles to perform printing with such ion-loaded ink, characterized in that the ink mist produced in a mist tank is once stored in a reservoir tank and then fed to the printing section.

Abstract: A large scale key-telephone system or telephone exchange system having approximately eighty extension channels and a push-button dial system has been disclosed. A common unit in the system is a DTMF oscillator, which is installed in each telephone set, according to a prior art. The present system is completely compatible with thus prior key-telephone system or exchange system.

Abstract: A conductive shield board for protecting an aperture board from discharge is mounted between a positive electrode and said aperture board in an ink mist type high speed printer.The ink mist type printer operates on the principle that an ion stream modulated by an aperture board according to the pattern of the character to be printed, charges the ink mist, which is then attracted by an electric field, to the surface of the paper. However, a high potential on a positive electrode for generating said ion stream sometimes causes an undesirable discharge between the positive electrode and the aperture board.In order to avoid said undesirable discharge, a conductive shield board is inserted between the positive electrode and the aperture board.

Abstract: A small scale electronic telephone exchange system of stored program control type having a plurality of trunks and a central computer has been disclosed. The trunks function to process the real time operation and, therefore, the central computer does not need to operate on a real time basis. The central computer always scans the condition of the trunks and the subscriber's telephone terminals and, upon detecting the change of said condition, it analyzes said change and performs the necessary process for said change. The present exchange system provides many new services but the cost of the system is reasonable.

Abstract: A key telephone system for subscribers is disclosed which includes at least a plurality of key telephone stations, a subscriber common equipment which connects the key telephone stations to each other and further connects the key telephone stations and an private automatic branch exchange, wherein said subscriber common equipment comprises switching network circuits, a register connecting circuit, line circuits, intra-office circuits, line circuit links, intra-office circuit links and a common controller, whereby each of said key telephone stations is connected to the subscriber common equipment through a pair of speech lines and a few control lines, and further said key telephone station can handle data processing services through said control lines by using a data terminal equipment attached to the key telephone station and a data processing unit by way of said subscriber common equipment.