Showing papers by "Sony Broadcast & Professional Research Laboratories published in 1979"

Properties of heavily doped GDSi with low resistivity

Abstract: Significant decrease in resistivity has been observed in glow-discharge-produced silicon (GDSi) containing 1019−1021 cm−3 phosphorous atoms. At the highest doping level a resistivity of 0.01 ω cm at room temperature was obtained. The temperature dependence of the resistivity follows the form, ϱ = ϱ0exp(T0/T)14, over a temperature range from 80–400 K. Optical absorption, which increased with wavelength and was roughly proportional to the conductivity, was observed in the longer wavelength side of the intrinsic absorption edge and it was ascribed to mobile charge carriers. Hall effect measurements have shown that μH of phosphorus doped GDSi is about 1 cm2 V−1s−1 and has a normal (negative) sign.

Time base error correcting apparatus

Abstract: Improved time base error correcting apparatus of the type wherein time base errors in a video signal, such as a video signal reproduced by a video signal playback device, are corrected. The apparatus includes a main memory into which picture elements contained in each line interval of the video signal are written at a write-in rate that is synchronized with the time base information contained in that video signal, and from which the picture elements are read out at a reference rate. A drop-out detector detects drop-out conditions which may occur in the video information and synchronizing information portions of the video signal. Drop-out indications are stored in a drop-out condition memory so as to represent the positions within a line interval that drop-out has occurred. These drop-out indications are written into and read out of the drop-out condition memory in synchronism with the writing in and reading out of picture elements from the main memory. Each picture element read out from the main memory is supplied to a drop-out compensator which is responsive to a read out drop-out indication to replace a dropped out picture element that is read out from the main memory with the picture element which had been in the same relative position in the immediately preceding line interval. A velocity error correcting device also is provided in order to correct velocity errors which may be present in each line interval. In the event that a velocity error cannot be detected, for example, because drop-out has occurred in the synchronizing portion of a line interval, the velocity error which had been detected for the previous line interval is used again in this and then the next-following interval, i.e., for a total of three consecutive line intervals. An offset voltage is added to the velocity error correcting operation for this third line interval, except that this offset voltage is subtracted during a drop-out compensating operation in that third line interval.

Electro-acoustic transducer

Abstract: An electro-acoustic transducer, such as a loudspeaker, a microphone, or the like, comprises a magnetic circuit having at least one air gap, a current conductor disposed in the air gap of the magnetic circuit to form a voice coil which is traversed by magnetic flux, and a vibratory structure mechanically coupled to the voice coil. The vibratory structure is comprised of a heat resistant film containing an epoxide-modified resin in which a heterocyclic compound containing a polyimide group is the main component. The voice coil is non-adhesively secured to the vibratory structure. For example, the voice coil is formed of a conductive substrate onto which the vibratory structure is coated and from which portions have been etched to form a generally spiral-shaped conductor. In one embodiment, the vibratory structure is a diaphragm; and in another embodiment, the vibratory structure is a bobbin having the voice coil wound thereon.

Method of and apparatus for indicating length and remaining recording capacity of a recording tape

Abstract: A method and apparatus for indicating the type, such as in terms of overall recording capacity, and remaining recording capacity of a recording tape. The tape is transported at a predetermined speed from a supply reel to a take-up reel. The rotations of the respective reels are sensed and the rotational periods T s and T t of the supply and take-up reels, respectively, are determined. Based upon these determined rotational periods, predetermined characteristics, such as the overall recording capacity, of the recording tape are indicated, irrespective of the arbitrary amount of tape which, initially, is wound upon the take-up reel. For example, a set of characteristics is stored for each value of T s 2 +T t 2 ; and the one set which is associated with the determined value T s 2 +T t 2 is selected. Also, the determined rotational periods T s and T t are combined with certain of said characteristics to indicate the amount of tape which remains upon the supply reel when that amount initially is unknown. The latter operation is carried out in accordance with the expression T R =P/1+α.sup. 2 -Q, wherein T R represents the recording capacity of the tape which remains on the supply reel, α 2 =(T t /T s ) 2 , and P and Q are constant values associated with the type of tape which is used and are determined by the diameter of the supply (or take-up) reel hub, the total length of recording tape, the thickness of the tape, and the speed at which the tape is driven.

Error correcting system

Abstract: Blocks of digital words containing an error correcting word are time interleaved into time-interleaved blocks of words, each of which contains no more than one word from any one of the original blocks The time-interleaved blocks of words are converted to a bit-by-bit serial digital data stream which is time-base compressed to permit insertion therein of an error detecting code word and synchronizing signals The resulting serial data stream may be recorded on a VTR After reproduction, each time interleaved block is checked for errors and is then time de-interleaved to reconstruct the original blocks of digital words If one or more errors exist in words in a time-interleaved block, no more than a single word in any one of the time de-interleaved blocks contains an error Single-word errors in a reconstructed block are corrected using the error correcting word accompanying the reconstructed block

PCM Signal transmitting system with error detecting and correcting capability

Abstract: A PCM (pulse code modulation) signal transmission system processes sequentially transferred digital information words including two error correcting words consisting of a parity code word and a b-adjacent code word and adds them to the digital information words, time-interleaves each of the information words and its error correcting words in the block into time-interleave blocks distributed over a predetermined time, adds an error detecting code to at least one of the time-interleaved blocks, and transmits at least one time-interleaved block and error correcting code associated therewith. Method and apparatus for de-interleaving and error correction based on the three appended codes are included.

Bobbin structure for high voltage transformers

Abstract: A coil bobbin for a fly-back transformer or the like having a bobbin proper. A plurality of partition members or flanges are formed on the bobbin proper with a slot between adjacent ones. At least first and second coil units are formed in the bobbin proper, each having several slots, formed between the flanges, and first and second high voltage coils are wound on the first and second coil units in opposite directions, respectively. A rectifying means is connected in series to the first and second coil units, and a cut-off portion or recess is provided on each of the partition members. In this case, a wire lead of the coil units passes from one slot to an adjacent slot through the cut-off portion which is formed as a delta groove, and one side of the delta groove is corresponded to the tangent direction to the winding direction.

Rotary head assembly

Abstract: OF THE DISCLOSURE A multi-channel recording and/or reproducing apparatus is disclosed, wherein a plurality of rotary magnetic heads scan a magnetic tape to form a plurality of skewed parallel tracks simultaneously. These heads are aligned substantially in the scanning direction on a single head base plate. Pre-ferably, these heads are so secured as to form parallel skewed tracks without guardbands therebetween. Each head has the same thickness, and is mounted on a head base. Even though the thickness of each head chip is the same, effective head gaps are formed to have different heights individually from the surface of the head base plate. When forming guardband-less plural tracks, an azimuth recording technique is intro-duced in order to avoid crosstalk between adjacent channels during reproduction.

Noise reduction system for video signals

Abstract: A recursive noise reduction system for a television system uses the spatial correlation in a frame difference signal derived by element-by-element subtraction of an incoming video signal from corresponding picture elements of a relatively noise-free stored video signal to redue noise in a video signal. The spatial correlation is used to suppress the components of the frame difference signal which are due to frame-to-frame changes in the video resulting from motion in the scene, thus producing a signal which contains substantially only the noise in the incoming video. The noise signal thus derived is subtracted from the incoming video signal to produce a noise-reduced output signal for display or recording. The noise-reduced output signal and the incoming video are added together in varying proportions according to the amount of scene-to-scene motion detected and the sum is stored for use in subsequent treatment of new incoming video.

Phonon Sidebands in Emission and Excitation Spectra for Ce 3+ in CaS

Abstract: Emission and excitation spectra for Ce 3+ in CaS have been observed at 75 K. They exhibit sharp phonon replicas due to pseudolocalized lattice vibrations. The observed frequencies of the pseudolocalized vibrations are 293 and 209 cm -1 in the emission spectra, and 282 and 206 cm -1 in the excitation spectra. Peak positions of the multiphonon background in the emission spectra depend upon the Ce concentration and preparation conditions, but the frequencies of the pseudolocalized vibrations remain unchanged.

Magnetoresistive displacement sensor and signal reprocessing circuits therefor

Abstract: A magnetoresistive displacement sensing transducer employs a plurality of sensing elements consisting of magnetically biased magnetoresistive stripes. Each sensing element is operative to produce a signal in response to linear or rotational displacement with respect to a magnetic grating. The phases of the signals from the plurality of sensing elements are relatively displaced to permit determining direction of displacement and to increase accuracy through interpolation. A signal processing circuit uses the signals from the sensing elements and optionally their sums and differences to drive a reversible counter which is thereby updated to retain a value corresponding to the position of the transducer or the magnetic grating.

Magnetic head tracking control system

Abstract: In an apparatus for reproducing video or other information signals recorded in successive parallel tracks extending obliquely on a magnetic tape or other record medium which is adapted to be longitudinally advanced, and with each of the tracks containing a positional signal, for example, constituted by a vertical synchronizing signal, at a predetermined position along the respective track, a magnetic head or transducer is movable in the direction generally along the tracks for reproducing the information and positional signals recorded therein and is mounted or supported by a bi-morph leaf or other transducer deflecting device which is operative, in response to the reception of an electrical drive signal, for deflecting the transducer or head in a direction transverse to the direction along the tracks, a circuit detects a time base error of the positional signal reproduced from each of the tracks, and a control circuit for providing the electrical drive signal to the transducer deflecting device is effective to vary such drive signal in accordance with the detected time base error. A time base variation of the reproduced signals is further detected, for example, in respect to the successive horizontal synchronizing signals of the reproduced video signals, and the electrical drive signal for the transducer deflecting device is also varied in accordance with such detected time base variation.

System for removing vertical vibrations from reproduced video

Abstract: In a television reproduction system in which recorded video for one field, either odd or even, is repeatedly scanned, such as for still or slow motion reproduction, and is displayed with a locally generated synchronizing signal which produces interlaced scanning having both odd and even fields on a television screen, video from adjacent lines is averaged when the recorded field being scanned is an odd or even field and the field defined by the synchronizing signal is the opposite type. When the recorded video is a color video signal, the luminance and chrominance components of the video signal are separately averaged, the chrominance component is inverted in dependence on the relationship between the phase of the color subcarrier of the recorded line being reproduced and the phase of the color subcarrier of the locally generated synchronizing signal.

Current control circuit

Abstract: In a circuit for controlling the current flow through a coil, such as the horizontal deflection coil of a television receiver, a first switching device including, for example, a first switching transistor and a first damper diode is connected in parallel with a first resonant circuit including a first capacitor and a first coil, which is the coil through which the current flow is to be controlled. A second switching device including for example, a second switching transistor and a second damper diode is connected in parallel with a second resonant circuit including a second capacitor and a second coil. First and second charging capacitors are connected in series with the first and second coils, respectively, and the power is supplied to the first and second resonant circuits for example through a third coil. Switching signals of the same frequency, for example, the horizontal frequency of a video signal, are applied to the first and second switching transistors with the phase difference between such signals being controlled to vary the relative voltages across the first and second charging capacitors and hence "to control" the current flowing through the first coil. The phase difference between the switching signals can be varied by a parabolic correcting signal having the vertical frequency of a video signal to cause the current flow through the horizontal deflection coil to correct for the side pin-cushion distortion of the raster of a cathode ray tube. In another embodiment of the invention, the phase difference between the switching signals can be modulated by a sawtooth wave signal having the vertical frequency so that the voltage across the first or second charging capacitor varies in a sawtooth manner at the vertical frequency and so that if a vertical deflection coil is connected across the first or second charging capacitor a sawtooth shaped current flow will take place through it, causing proper vertical deflection.

Rotating magnetic head piezo-electric assembly and drive circuitry for video tape recorder

Abstract: A magnetic head assembly for a video tape recorder includes a piezo-electric support, preferably constituted by a bi-morph leaf or leaves, supported at one end, for example, on a rotary portion of a tape guide drum, and a magnetic head mounted at the other end of the piezo-electric support, and the piezo-electric support has two pairs of first and second electrodes secured on opposed major surfaces, respectively, of the support and extending in the direction between the ends of the support, that is, in the lengthwise direction of the latter, with such pairs of electrodes being parallel and spaced from each other in the direction across the support. Thus, by applying suitable control voltages between the first and second electrodes of the two pairs thereof, the piezo-electric support can be made to flex or bend longitudinally and/or torsionally, for example, for correcting tracking erros and/or for varying the azimuth angle, respectively, of the mounted head.

Tape cassette brake assembly

Abstract: In a cassette for use in a magnetic recording and/or reproducing apparatus and which is of the type having a housing containing freely rotatable reels having magnetic tape wound thereon with the tape extending between said reels being guided to direct a run thereof across an access opening in said housing, an improved brake assembly is provided for automatically preventing excess slackness in the run of tape when the cassette is disengaged from the magnetic recording and/or reproducing apparatus and for automatically releasing the tape run when the cassette is so engaged. A holder having a resiliently flexible element slidably disposed in a gap provided therein is arranged with respect to a support element such that the free end portion of the element preferably having a low coefficient of friction normally urges a tape portion into pressing contact with the support element so as to provide the braking action. When the tape run is drawn out of the access opening or otherwise tensioned, however, the element is flexed thereby such that only the free end portion having the low coefficient of friction is in sliding contact with the tape, whereby the automatic release action is provided.

Tracking control apparatus for a rotary head, variable speed signal reproducing system

Abstract: The present invention is intended for use in a signal reproducing system of the type having at least one rotary transducer for scanning traces across a movable record medium, such as a magnetic tape, to reproduce signals from previously recorded record tracks. Each transducer is supported on a displaceable support member that is responsive to control signals to displace the transducer relative to the record tracks. The record medium is movable at a speed which may be less than, equal to or greater than the speed at which the signals originally were recorded. A frequency generator generates speed representing pulses whose frequency is a function of the speed at which the record medium is moved. A cyclical, or resettable, counter cyclically counts the speed representing pulses. A level generator generates a signal level corresponding to the count then present in the counter at the time that a transducer advances to the middle portion of a scanning trace. The generated signal level is used as a control signal to correspondingly displace the transducer support member. This displacement provides general compensation for the deviation between the scanning trace of the transducer and the record track which is scanned thereby. In a preferred use of the present invention, the signal reproducing system is a VTR, and tracking compensation is provided for slow or fast modes of reproduction. In accordance with another feature, a sawtooth signal having a period equal to a head scanning period, and an amplitude determined by the speed at which the record medium (or tape) is moved is added to the generated level in order to provide substantially continuous error correction of the head scanning trace.

Tone arm assembly

Abstract: A tone arm assembly for record players having a first motor for rotating a tone arm in the vertical direction, a second motor for rotating the tone arm in the horizontal direction with respect to a record disc, respectively, a detector for detecting low frequency vertical and horizontal vibrations of the tone arm during the reproduction of a record disc and feeding back an output signal of the detector to the motors so as to cancel the vibrations, whereby high fidelity reproduction of sounds can be performed. Further, the stylus pressure adjustment and elevation angle adjustment of the tone arm are also performed.

Effect of Arsenic Partial Pressure on Capless Anneal of Ion‐Implanted GaAs

Abstract: A capless anneal of ion‐implanted was performed under different partial pressure of arsenic controlled by decomposition of arsine. Sheet carrier concentration of implanted with Mg or Si increased with increasing arsenic partial pressure, while that of S+ implanted showed an opposite trend which corresponded to the different lattice sites occupied in the crystal. The site‐occupation rate and ionization rate of implanted impurity atoms were thermodynamically determined by analyzing the variation of the sheet carrier concentration with the partial pressure of arsine. The site‐occupation rate was found to be larger than 90% for the case of Mg or S implantation. The ionization rate of the substitutional atoms limited the doping efficiency of implanted impurities in these cases, while both the site‐occupation rate and the ionization rate were responsible for the doping efficiency of Si implantation.

Tape cassette and label inspection system therefor

Abstract: Markings on a tape cassette label and on its tape leader cooperate with an inspection system which senses the markings to automatically compare the actual characteristics of the tape marked on the tape leader such as, for example, length and type of magnetic powder, with the characteristics described on the cassette label. In the event that the tape type and label description disagree, an alarm or removing mechanism may be automatically actuated to remove the mislabelled cassette.

Method for producing corrosion-, heat- and oxidation-resistant materials

Abstract: A method for producing a corrosion-, heat- and oxidation-resistant materialhich comprises coating a substrate composed of at least one material selected from metals, carbonaceous substances and ceramics with a semi-inorganic compound, and heat-treating the coated substrate; said semi-inorganic compound being either (1) a modified organoborosiloxane compound obtained by reacting an organoborosiloxane compound with at least one organic compound selected from the group consisting of polyhydric aliphatic alcohols, aromatic alcohols, phenols and aromatic carboxylic acid at a temperature of from 250° to 450° in an atmosphere inert to the reaction, or (2) a modified organoborosiloxane compound obtained by adding at least one catalyst selected from the group consisting of Ni, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Co, other transition metals, actinoid metals, lanthanoid metals, alloys of these metals, persulfate salts, organic peroxides, and halides of Al, Fe, B, Ga and In to an organoborosiloxane compound, and heating the mixture in a non-oxidizing atmosphere at a temperture of 300° to 550° C.

Color picture-in-picture television receiver

Abstract: A system for inserting a reduced picture of a first channel broadcast into a picture of a second channel broadcast on a single screen in a picture-in-picture television receiver. First and second video signal chains are provided. A first group of three memories connects to the first chain for memorizing R, G and B signals obtained from a first field of video signals of the first channel broadcast. A second group of three memories is connected to the first chain for memorizing R, G and B signals obtained from a second field of the video signals of the first channel broadcast. With the disclosed system, picture flicker problems are solved and the horizontal resolution is improved.

Block sync signal extracting apparatus

Abstract: A sync signal extracting circuit suitable for a digital information processing apparatus, such as a digital video tape recorder, is provided, which can promptly detect an incorrect sync state and which can quickly and accurately recover a correct sync state. The circuit extracts the sync signals or portions from a digital information signal consisting of a plurality of successive blocks, each consisting of N successive bits (where N is an integer) and each having a sync signal or portion consisting of a predetermined sync bit pattern and a data portion. The circuit comprises a sync bit pattern detecting circuit for generating a detected sync signal when it detects the occurrence of the sync bit pattern in the information signal, a counting circuit for providing a count having a successive one of N cyclical count values in response to each successive bit of the information signal and generating a counted sync signal at every Nth bit of the information signal, and a check mode circuit for memorizing the count of the counting circuit when the detected sync signal is generated other than in conjunction with the counted sync signal, for generating a checked sync signal if a detected sync signal is generated the next time the counting circuit equals the memorized count, and for changing the count of the counting circuit in response to the generation of the checked sync signal so that the counting circuit will be synchonized with the detected sync signals which gave rise to the checked sync signal.

Digital servo control circuit

Abstract: In a digital servo control system, the duty cycle of a pulse width modulated signal for controlling a drive motor is determined by digital numbers representing phase and/or speed errors preset into a memory and circulating counter. The circulating counter is driven by a clock signal which performs a number of cycles during each basic timing interval. A pulse width modulated signal is initiated by a timing pulse and is terminated by each return to zero of the most significant digit of the circulating counter. The time at which the most significant digit of the circulating counter returns to zero at the end of each of its cycles is determined by the number initially preset into it. The memory is gated with the output of a four-bit counter, which increments at the same rate that the circulating counter cycles, to either lengthen each pulse width modulated signal by one clock cycle or not. The number of times the pulse-width modulated signal is lengthened in a basic timing interval is proportional to the number preset into the memory. The contents of the memory and the circulating counter are periodically changed to correspond to detected speed and/or phase errors to update the duty cycle of the pulse width modulated control signal.

Voice coil bobbin connection to loudspeaker diaphragm of honeycomb core sandwiched by sheets

Abstract: A diaphragm for a flat plate electroacoustic transducer such as a loudspeaker includes first and second diaphragm sheet members having a honeycombed core structure sandwiched therebetween and includes an interconnection between each diaphragm and the piston or voice coil bobbin to avoid shifts and delays in transmitting vibration to each diaphragm and eliminate the tendency to introduce extraneous auditory sounds.

Multi band radio receiver system with phase locked loop

Abstract: A multi band radio employs frequency counters to determine a scaling factor during coarse tuning which is employed in a phase locked loop to control the frequency of a local oscillator during normal operation. Frequency counters count the frequency in the phase locked loop and in a low variable frequency generator to determine the rf frequency to which the receiver is tuned. Read only memories provide band and frequency displays with control signals based on the counted frequencies.

Apparatus for controlling the speed and direction of rotation of a DC motor

Abstract: A single pickup head generates an alternating signal proportional to the rotational speed of a DC motor which can be rotated in either of two directions, and such alternating signal is employed by speed and/or phase control circuits to control the motor speed relative to a reference speed in a selected one of the two directions. An overspeed sensing circuit detects speed runaway, which can occur when the motor is rapidly rotated in the direction opposite to the selected direction, and the overspeed sensing circuit then interrupts the motor drive voltage until the motor speed decreases to below its normal speed. At and below normal speed in the undesired direction, the normal torque acts in the selected direction to rapidly reverse the direction and to accelerate the motor to normal speed in the selected direction.

Magnetic signal field sensor that is substantially immune to angular displacement relative to the signal field

Abstract: Apparatus is provided for sensing an external magnetic field. This apparatus is comprised of first and second coplanar magnetoresistive elements, each magnetoresistive element having a main current conducting path and also having anisotropic resistance as a function of the direction of the resultant magnetic field applied thereto. First and second equal bias magnetic fields are supplied to the first and second magnetoresistive elements, respectively, these bias magnetic fields being supplied at different angles with respect to their associated magnetoresistive elements. In one embodiment, the current conducting paths of the magnetoresistive elements are perpendicular to each other, and the respective bias magnetic fields extend in opposite directions, these directions being parallel to one of the main current conducting paths. In another embodiment, the main current conducting paths of the respective magnetoresistive elements extend in the same direction, and the respective bias magnetic fields are at an angle of, for example ±45° to these main current conducting paths. The first and second magnetoresistive elements are connected in series with each other, and a d.c. current is supplied to this series connection. An output signal representing the magnitude of an external magnetic field as supplied to the magnetoresistive elements is derived from the junction formed by the series-connected elements.

Electroacoustic transducer with magnetic flux directed slantly across a diaphragm

Abstract: A flat type electro-acoustic transducer such as a ribbon type loudspeaker has a magnetic circuit comprising a pair of air gaps and a diaphragm having a spiral coil disposed in the air gaps. In this case, the magnetic flux in the air gaps is slantly across the diaphragm.

White balance control circuit

Abstract: A white balance control circuit for an encoded composite color television signal is disclosed in which three primary color signals of green (G), blue (B) and red (R) are matrixed to be mixed color signal components, color difference signals of R-G and B-G are provided from the mixed color signal components, and gain control circuits provided on the signal transmission paths of two primary color signals of R and B are so controlled in their gains that the color difference signals become zero, when the white balance adjustment is done.