Showing papers by "Sony Broadcast & Professional Research Laboratories published in 1974"

Semiconductor device with high voltage breakdown resistance

Abstract: A semiconductor device including a substrate of semiconductor material having charge carriers of one conductivity type and a main region of opposite conductivity type. A ring of said opposite conductivity type is disposed around the main region and an auxiliary region of said opposite conductivity type is disposed on the opposite surface of the substrate. The said rings and the said auxiliary region are spaced from the main region by distances that permit the depletion region of the main region to reach the ring and the auxiliary region when the main region is reversed biased with respect to the substrate.

Video display system employing drive pulse of variable amplitude and width

Abstract: A video display system employs a flat panel of the X-Y matrix type with a brightness control circuit in which both the amplitude and the duration of driving pulses for the display panel are varied in response to variations in the sequentially sampled level of input video signals. In a preferred brightness control circuit, variations in the sequentially sampled level of the input video signals are converted into digitally coded signals which selectively energize respective pulse generators operative to produce pulses of correspondingly weighted durations and amplitudes which overlap in time, and such pulses are combined to provide the amplitude- and width or duration-modulated driving pulses for the display panel.

Electret transducer having an electret of inorganic insulating material

Abstract: An electret transducer in which the electret material is an inorganic insulator sheet with electric charges in it and is juxtaposed to an electrode, and either the sheet or the electrode is mechanically deformable to change the distance between the two, thereby changing the electric charge induced in the electrode by the charged electret sheet. In a preferred form, the electret material comprises a multilayer sheet of insulating materials. The method of forming the transducer includes at least the steps of vapor-depositing a thin layer of inorganic material on a substrate and subjecting the exposed surface of the insulating material to a source of electric charge for a time sufficient to implant charges in the insulating material. If the insulating material is to be deformable, it should be deposited on a thin layer of metal which, in turn, has been deposited on a thicker substrate. A spacer layer of metal is deposited on top of the charged insulating material. Thereafter, selected areas of the substrate and of the spacer layer are chemically removed to leave the thin metal layer and the charged insulating material free of support except around the periphery of such open area. The ability of the insulating material to accept and hold a charge may be improved by depositing the insulating material as two separate layers of different materials, one immediately on top of the other.

Automatic assembly apparatus for inserting electronic connecting pins to and/or for mounting electronic parts on printed circuit boards

Abstract: Apparatus for inserting electronic connecting pins into and/or mounting leadless electronic parts such as capacitors, resistors, inductors and the like on a printed circuit board from a dispensing device, and particularly for securing the fragile electronic parts with uneven lengths onto the printed circuit board.

Method and apparatus for recording and/or reproducing a video signal on a photographic record disc

Abstract: Composite television signals are recorded in a spiral track or in a series of concentric circular tracks on a record disc. Line sequential signals are optically recorded in the radial direction on a record disc with one horizontal line interval of the composite television signals corresponding to the width of the record track, and with the successive line signals being arranged in the circumferential direction of the track. Pulse-time modulated video and audio signals are recorded as a series of depressions all having the same width and the same depth, and with the varying length between the adjacent depressions corresponding to the information signal. A video signal reproducing head is provided adjacent to the optical record disc for optically reproducing video signals from the tracks on the disc which is, during reproduction of the signals, rotated at an extremely low speed so as to facilitate the reliable tracking of the signal reproducing head in respect to the recorded tracks.

Semiconductor device with a high breakdown voltage characteristic

Abstract: A semiconductor device is provided having at least two semiconductor regions of opposite conductivity type and forming a planar-type PN junction. A field limiting ring is disposed spaced from the PN junction. A high-resistivity polycrystalline silicon layer covers the PN junction and the field limiting ring.

Method of making electret

Abstract: A method of making an electret by annealing a corona charged dielectric film on a metal plate is disclosed.

Signal transmitting apparatus using A/D converter and monostable control circuit

Abstract: An amplitude adjustment circuit transmits an analog signal to an analog-to-digital converter. If the resulting digital signal reaches the maximum permissible digital value, a monostable control circuit is triggered to cause the amplitude adjustment circuit to reduce the level of the analog signal a certain amount. If the digital signal again reaches the maximum permissible digital value before the control circuit returns to its stable condition a second monostable circuit is triggered (and the first one is retriggered) to cause the amplitude adjustment circuit to reduce the level of the analog signal another amount. The unstable interval for the second monostable circuit is shorter than for the first, and, in the absence of further triggering, both such circuits return to their stable states in succession. The digital signals are used to reconstruct the analog signal in apparatus similar to the encoding apparatus and including amplitude adjustment apparatus controlled by the amplitude compression signals.

Remote control system for electric apparatus

Abstract: A remote control system for selectively controlling plural functions of electric apparatus comprising a combination of an improved transmitter for generating a command signal of a single frequency which is transmitted intermittently for a plurality of intervals of time, the length of each of which is determined in response to selection of one of the plural functions, and a receiver for receiving the command signal and producing a control signal for controlling the selected function in response to the length of each of the intervals and to the number of the intervals of the received command signal.

Signal handling system for minimizing dropout effect

Abstract: A system for handling pulse encoded signals includes several parallel signal paths to carry pulses on which a signal has been encoded. The encoding is based on a predetermined amplitude value, or weight, for each pulse, and each signal path receives all pulses having the same weighting factor. A switching system is provided to switch the signals received on the various paths to different paths in a determinable order at a repetition rate commensurate with the pulse encoding repetition rate. The signals are then transmitted along the signal paths and are then switched back to the original order for pulse decoding. If pulse bits are lost in the second path, an interpolation may be made to provide a reasonable restoration of the signal to minimize the dropout effect. The switching of signals back to the original order virtually eliminates the possibility of having two successive dropouts of the same pulse weight in the signals to be decoded, and thus eliminates the possibility of having no standard of interpolation in the reconstructed signal.

Apparatus for measuring the direction and relative position between a body and a pick-up using a magnetoresistive pick up

Abstract: An improved measurement system for determining the degree of out of synchronism or phase difference of a moving body carrying a row of magnets with respect to a reference signal. A pair of precisely spaced magnetoresistance elements are provided each having a plurality of stripes formed of a ferromagnetic material with an anisotropic characteristic. Each element has an AC power source connected across it, the two power sources being 90° out of phase. Positioned near the magnetoresistance elements is the row of magnets comprised of a plurality of magnet pairs having South pole ends abutting and forming a specific wavelength. As the row of magnets moves relative to the magnetoresistive elements, a changing magnetic flux causes resistance changes in the elements which in turn produces a modulation of the AC power sources which is sensed at the middles of the magnetoresistance elements. These modulated signals are combined to produce a signal whose phase is compared with a reference signal of the same frequency as the AC power sources.

Protective circuit for field effect transistor amplifier

Abstract: A transistor amplifier which includes at least one field effect transistor for amplifying an input signal and supplying a corresponding output signal to a load, and a biasing circuit for supplying a predetermined biasing voltage to the field effect transistor so as to operate the latter with a suitable biasing current, is protected against overloading of such transistor by a detecting circuit for detecting an overload condition of the field effect transistor, and a switching circuit operative to maintain the biasing voltage at a predetermined value and to shunt the input signal to the load when an output signal of the detecting circuit exceeds a predetermined value. In a preferred embodiment, the output stage of the amplifier is constituted by a push-pull amplifier having at least a pair of field effect transistors with triode characteristics so as to have excellent characteristics, such as, low switching distortion, high linearity and low output impedance, and thereby be particularly suited for use as an audio power amplifier. Further, the detecting circuit is preferably of the load impedance detecting type, for example, responsive to both the load current and the load voltage, so as to avoid misoperation of the protective circuit, that is, unnecessary shunting of the input signal to the load, as when the latter is constituted by a condenser speaker.

Apparatus for recording and/or reproducing information signals having automatic focusing

Abstract: An apparatus for recording and/or reproducing information signals is disclosed in which a light beam is substantially forcussed on the mirror surface of a recording medium, the information signals are recorded on said recording medium with said light beam, and the recorded information signals are reproduced with said light beam. The apparatus comprises an optical detecting device for detecting the light beam reflected on the recording medium at least two different positions and a control device for controlling the focus of said light beam in accordance with the output signal from the optical detecting device.

Cassette holding device for tape recording and/or reproducing apparatus

Abstract: In a cassette-type apparatus for recording and reproducing video signals on a magnetic tape, a cassette holding device is provided for receiving the cassette in an elevated, tilted position and then lowering to an operative position. During at least the final increment of movement of the cassette to its operative position, the cassette holding device maintains the cassette housing substantially in parallel orientation to the plane of the chassis, while moving the cassette in a direction substantially perpendicular to such plane for ensuring proper engagement with locating posts, reel support and drive members. The holder is mounted by a large first lever and a second short lever which are mounted between the sides of the holder and the chassis.

Non-linear amplifier

Abstract: A non-linear amplifier is disclosed including an amplifying transistor for amplifying an input signal, an output amplified signal being derived from the amplifying transistor. A series of PN junctions is provided to supply a determined bias voltage to the amplifying transistor. An emitter-follower stage, comprised of at least one emitter-follower transistor amplifier, is connected to an input of the amplifying transistor for compensating the bias voltage applied thereto. In one embodiment, the input signal is amplified by a power of n wherein n PN junctions are connected in parallel with (n-1) emitter-follower transistor amplifiers. The input signal is supplied through the (n-1) emitter-followers to the base electrode of the amplifying transistor. In an alternative embodiment, the input signal is amplified by a power of 1/n wherein (n-1) PN junctions are coupled to the emitter electrode of the amplifying transistor and (n-1) emitter-follower transistors are connected in cascade to the base electrode of the amplifying transistor. In this latter embodiment, an output transistor is connected to the output of the emitter-follower stage.

Magnetic rotary head recorder with automatic tape loading and unloading

Abstract: In a magnetic recording and/or reproducing apparatus having a tape guide drum, at least one rotary magnetic head moved in a circular path coinciding with the circumferential surface of the drum for scanning a magnetic tape wrapped about at least a portion of that surface, a tape supply such as, a cassette containing reels on which a magnetic tape is wound, a capstan spaced from the guide drum, a holder for receiving and positioning the cassette at a location spaced from the guide drum, and a tape loading and unloading device which comprises a support ring rotatable around the drum between inactive and operative positions in a substantially horizontal arcuate path that extends adjacent the capstan and the holder, a tape engaging member including a pinch roller extending upwardly from the support ring and being movable with the latter in the aforementioned arcuate path for projecting from below into an opening of the cassette positioned by the holder and engaging the tape extending across such opening with the support ring in its inactive position and for withdrawing a progressively extended loop of tape from the cassette and wrapping one side of the extended tape loop about at least a portion of the guide drum circumference in response to movement of the support ring from the inactive to the operative position at which the pinch roller is located within the tape loop adjacent the capstan with the tape of the loop therebetween; the support ring of the tape loading and unloading device is formed of first and second arcuate parts which are pivotally connected to each other in end-to-end relation to permit swinging of the first part relative to the second part between a raised position coplanar with the second part and a depressed position in which the first part is inclined downwardly from the second part, the first part of the support ring carries all of the tape engaging members and extends toward the cassette holder in the inactive position of the support ring, and the support ring is carried by a plurality of rollers spaced apart about the arcuate path with each one of the rollers carrying the first part of the support ring in the inactive position of the latter being substantially vertically movable to move the first part between its raised and depressed positions. By reason of the foregoing, the cassette holder may have a fixed horizontal base over which the cassette can be slidably moved to and from an operative cassette position with the first part of the ring in its depressed position to dispose the tape engaging members below the holder base. With the cassette in its operative position, the first part of the support ring can be moved to its raised position for projecting the tape engaging members into the cassette opening. Further, reel drive members are movable axially between depressed positions below the holder base and raised or operative positions in which the reel drive members project through the holder base for engagement with the reels in a cassette operatively positioned on such base, and a control mechanism is provided for simultaneously moving the first part of the support ring and the reel drive members between their respective depressed and raised positions.

Tension control device for a video tape recording and/or reproducing apparatus

Abstract: A tension control device, particularly for an apparatus recording and/or reproducing video signals on a tape which is wound on and extends between supply and take-up reels, includes a pivoted tension control arm urged by a tensioning spring against a run of the tape between the reels for detecting the tape tension and correspondingly controlling a brake resisting rotation of the supply reel so as to maintain the tape tension at a level determined by the spring force, and the spring force is made adjustable for varying the tape tension which is to be maintained by connecting the tensioning spring to a movable anchor member which is substantially counter-balanced, for example, by another spring acting on the anchor member in opposition to the tensioning spring. Movements of the anchor member for adjusting the force of the tensioning spring are effected by a manually actuable control element preferably having an irreversible coupling to the anchor member which provides a substantial mechanical advantage, for example, in the form of a cam member turnable with the control element and engaged by a cam follower on the movable anchor member.

Protective circuit for transistor amplifier

Abstract: A protective circuit for a transistor amplifier is disclosed which includes a load impedance detecting circuit provided between an output terminal of a transistor amplifier and a load terminal, a circuit for detecting an abrupt surge voltage of a voltage source for the amplifier and a muting circuit are provided between an input terminal of the amplifier and a reference point, the muting circuit being operative to limit an input signal applied to the input terminal of the amplifier in response to output signals of the load impedance detecting circuit. A protective circuit having a thermal sensing circuit for detecting a temperature rise of an output transistor above a predetermined level which shuts off the amplifier is described as one embodiment.

Bright tin-nickel alloy plating electrolyte

Abstract: A bright tin-nickel alloy plating electrolyte consists essentially of an aqueous main plating liquid containing a stannous salt, a nickel salt and an alkali-metal pyrophosphate, with a brightener additive in such main plating liquid which is a compound having a plurality of amino groups, for example, ethylenediamine, 1,2-propanediamine, 1,3-propanediamine, 1,4butanediamine, pentamethylenediamine, hexamethylenediamine, hydrazine, guanidine, urea or thiourea, and with a further addition of ammonia or an ammonium salt. The electrolyte may further have added thereto a compound having at least one -SX group in this electrolyte (in which X represents hydrogen, sodium or potassium), a peptone and/or protein, or a neutral amino acid which is free of sulphur or a salt thereof.

Tape apparatus including means to count length-related pulses for video editing

Abstract: Video tape apparatus using a cassette with a tape running between reels. A short loop of tape is drawn out and follows a path past an erase head. This short path offers low friction and permits fast tape movement in Fast Forward and Rewind modes while allowing the erase head to pick up tape synchronizing pulses. A counter counts these pulses to indicate the length of tape passing the head during the count, thus facilitating reaching a predetermined point quickly for editing tape. The short loop also more correctly aligns the tape to facilitate withdrawing it from either reel and feeding it onto the other. At slower tape speed for Playback and Record modes, pulses to be counted can be derived from the video signal, from a control head, or from a generator that responds to speed of the recording head shaft.

Magnetic recording and/or reproducing apparatus

Abstract: In recording PAL television signals, the chrominance signal components of field intervals are recorded in successive parallel tracks on a record medium. The ends of the margins between the line intervals of each field are recorded in each of the tracks and are aligned, in the direction transverse to the lengths of the tracks, with the adjacent ends of such margins in the next adjacent tracks. Interference, or cross-talk, between signals recorded in adjacent tracks is reduced or eliminated during reproduction by converting the alternating polarity chrominance component into one of fixed polarity, similar to an NTSC signal, and then recording the information signals with different first and second carriers in the adjacent tracks, respectively. Such first and second carriers for signals recorded in adjacent tracks may be distinguished from each other by their respective frequency and/or polarity characteristics. When the signals recorded in a particular track are reproduced, the cross-talk signals from adjacent tracks can be conveniently suppressed or eliminated, for example, with the aid of a simple comb filter, by reason of the different frequency and/or polarity characteristics of the carriers of interfering signals. The signals are then reconverted to PAL form to be played back on apparatus designed to reproduce images in response to PAL signals.

Adhesive composition containing phenoxy and epoxy resins and a cross-linking agent therefor

Abstract: A structural adhesive composition which is particularly suited for bonding or laminating a metal foil to an epoxy resin impregnated glass fiber plate, for example, as in the production of copper clad painted circuit boards, comprises a phenoxy resin having the formula WHEREIN M is a metal atom having a valence of at least one, n is an integer including zero, m is an integer, R1 is a member selected from the group consisting of hydrogen atom, alkyl, unsaturated aliphatic, cyclic alkyl and aryl, and R2 is a member selected from the group consisting of alkyl and aryl which has at least one electron donor atom to form a chelate with said metal atom The epoxy resin is preferably present in the composition in an amount between 20 and 400 wt% based on the amount of the phenoxy resin, and the cross-linking agent is preferably present in the composition in an amount between 2 and 30 wt% based on the amount of the phenoxy resin WHEREIN N IS 50 TO 100, A LOW MOLECULAR EPOXY RESIN HAVING MORE THAN TWO EPOXY GROUPS AND AN EPOXY VALUE LESS THAN 4,000, AND A CROSS-LINKING AGENT WHICH EITHER HAS AT LEAST TWO AZIRIDINE RINGS AT THE ENDS OF THE MOLECULAES THEREOF TO REACT WITH THE HYDROXYL GROUP (OH) of said phenoxy resin and with said low molecular epoxy resin for providing a high cross-linking density, or which is a chelate of an organic metal compound having the formula

Video projecting system

Abstract: A video projecting system having a cabinet with one end being opened, a screen in the cabinet and its upper portion, a movable side board attached to the cabinet at the lower side of its opening, and a projector and a mirror both attached to the movable side board on its inner surface, in which when the movable side board is drawn out a picture from the projector is reflected on the mirror and then projected onto the screen.

Signal transmitting system including A-D and D-A converters

Abstract: A signal transmitting system including an A-D converter for converting an analog input signal to a digital signal and a D-A converter for re-converting the digital signal to an analog output signal is provided with improved fidelity without increasing the number of digital levels and digital bits in the A-D and D-A converters. In such signal transmitting system, the analog input signal is applied to a plurality of voltage level comparators for comparison therein with respective reference voltages which sequentially differ from each other by predetermined voltage increments, the levels of the reference voltages are periodically varied by means of a switching signal, outputs from the level comparators are applied to an encoder which produces a corresponding digital signal, a decoder receives the digital signal and reconverts the latter to an analog signal, and the analog signal from the decoder is added to a switching signal which may be the first mentioned switching signal, or at least has the same period as the latter, to provide a resulting analog output signal which relatively closely corresponds to the analog input signal.

FET having a linear impedance characteristic over a wide range of frequency

Abstract: A FET is provided having a linear impedance characteristic over a wide range. It comprises a semiconductor substrate of one impurity type with source and drain regions formed in one surface thereof of opposite highly doped impurity type. An insulating layer overlies said one surface and is of a relative thin thickness between a point above said source region and a point above said drain region, and is of a relative thick thickness throughout the rest of its extent. A polycrystalline resistance layer overlies the insulating layer over its thin thickness portion and over some of the thick portion of the insulating layer lying above the source region. Source and drain electrodes are formed on the insulating layer and have portions thereof extending through windows in the insulating layer into contact with said source and drain regions respectively. A gate electrode is formed on the resistive layer above the thick portion of said insulating layer and extends back from the drain facing face of the source region by a predetermined distance.

Automatic gain control circuit

Abstract: An automatic gain control circuit for a stereo amplifier having separate gain control means in each channel, each gain control means being actuated by control signal means from the same channel and from the other channel. The control means of the same channel has a relatively short attack time and a relatively long recovery time while the control means actuated by the other channel has a relatively long attack time and a recovery time that is substantially shorter than the recovery time of the control means actuated from the same channel as the gain control means.

Brushless DC motor driving circuit

Abstract: A brushless DC motor having a plurality of stator windings and a rotor made of a magnet is driven by energizing the stator windings successively, and in which signals induced in the plurality of stator windings resulting from the rotation of the rotor are detected as position signals of the rotor and at least one of the stator windings which corresponds to the position signal is supplied with a driving signal.

Signal switching apparatus

Abstract: Signal switching apparatus is disclosed whereby a selected one of a plurality of supplied input signals is switched to an output terminal, including a switching circuit having plural input terminals for receiving the input signals and an output terminal to which a selected one of the received input signals is supplied; a control circuit coupled to the switching circuit and responsive to a control signal applied thereto for selectively actuating the switching circuit to thereby enable the switching circuit to supply one of the input signals to its output terminal; a clamping circuit coupled to the switching circuit and responsive to the control circuit for inhibiting the switching circuit from supplying more than one selected input signal to the output terminal; and an input signal supply circuit for supplying the plural input signals to the input terminals of the switching circuit.

Distortionless FET switching circuit

Abstract: A switching circuit is disclosed in which a first field effect transistor (which will be hereinafter referred to as an FET simply) is provided in such a manner that its source-drain are connected between an input terminal and output terminal and its source and drain electrodes are connected to a bias source through resistors, and a second FET of a source follower type is provided such that its gate electrode is connected to the source electrode of the first FET and its source electrode is connected to the gate electrode of the first FET. In this case, by changing the source electrode voltage level of the second FET, the first FET is made on and off to perform a switching operation.

Circuit for automatically correcting the timing of clock pulse in self-clocked pulse signal decoders

Abstract: In dynamic modulation (D.M.) of non-return-to-zero pulse signals, the only condition under which the D.M. signal would remain in the same state, either 1 or 0, for two consecutive pulse intervals is when the NRZ signal includes the sequence 101. Two sampling signals at the proper clock repetition rate are generated from the D.M. signal by the decoder and are successively used to sample the D.M. signal and to sample the signal resulting from the first sampling. Information of the state of the D.M. signal at the time of the first sampling is retained to be compared with the state of the D.M. signal at a later time, and the state of one of the compared signals is separately compared with the state of a signal between the first-compared signals. If the wrong clock pulses midway between the correct clock pulses are used in making the comparisons, a correction signal will be generated in the last half of the second consecutive pulse interval in which the D.M. signal remains in the same state. This correction signal is used to adjust the clock pulse selector to select the correct pulses.