Abstract: A magnetic recording/reproducing apparatus for recording a signal onto a magnetic tape and reproducing a recorded signal comprises magnetic heads mounted on a rotary cylinder, a tape driving mechanism, high speed running control device for driving a reel shaft to rotate at a speed higher than a normal recording/reproducing speed, tape-running detecting device, reel motor starting device for generating a ramp voltage having a suitable gradient, a switch for turning on/off the tape running speed control by the high speed running control device and adding device. In the apparatus the cylinder rotation speed follow-up control never comes out in making the high speed running of the tape rise, so that the relative speed between the head and tape is maintained to substantial constant.

Abstract: In an information recording/reproducing apparatus for recording/reproducing a digital audio signal on/from a magnetic medium, a modulator/demodulator for modulating/demodulating the digital signal by offset quadrature phrase shift keying (O-QPSK). This technique is particularly applicable to the multi-layer recording of video and audio signals in a video tape recording/reproducing system and has the advantage of avoiding interference between the recorded digital audio and video signals at the time of reproduction.

Abstract: A digital signal recording/reproducing apparatus for enabling recording/reproduction at variable speeds including normal speed, and at least one of N-times normal speed and 1/N-times normal speed while maintaining the reproducing frequency constant so as to not require switching of analog circuits. At the time of reproduction at normal speed, N-times normal speed or 1/N-times normal speed, the feed speed of the magnetic tape and the timing of picking up of a reproducing signal from the magnetic tape are varied while the speed of revolution of a cylinder of a rotary head is maintained constant so that the timing of detection of pilot signals for generating a tracking error signal is varied to cope with difference in track scanning conditions in recording and reproducing modes.

Abstract: The present invention relates to an apparatus for recording a digitized signal. If a recording apparatus is switched from a recording mode to a non-recording mode and then switched from the non-recording mode to a recording mode, there is produced a portion between two records where the records are not continuous. When such a portion is reproduced, abnormal data come to be reproduced because of existence of discontinuity between the prior and subsequent data. And, if a digital audio signal is similarly recorded, it follows that an abnormal sound is generated when such a portion is reproduced. Then, by recording an anti-format signal in the discontinuous portion, the reproduction of abnormal data or generation of abnormal sound can be prevented from occurring.

Abstract: A rotary head type digital signal recording and/or reproducing apparatus wherein for 1/2 speed recording and/or reproducing from a magnetic tape, a tape feed speed is decreased to 1/2 times the normal speed, and a recording/reproducing interval becomes 2 times that of the normal mode of operation utilizing at least two rotary heads mounted at adjacent positions on a rotating cylinder with one of the rotary heads having a plus azimuth angle and the other having a minus azimuth angle. For 2 times speed recording/reproducing, a tape feed speed increases to 2 times the normal speed, and a recording/reproducing interval becomes 1/2 that of the normal mode of operation utilizing at least two rotary heads mounted on a rotating cylinder at opposite positions of a rotary axis of the cylinder, with one of the two rotary heads having a plus azimuth angle and the other having a minus azimuth angle.

Abstract: A method of producing a tracking control signal in a rotary head type magnetic recording and reproducing apparatus and a rotary head type magnetic recording and reproducing apparatus capable of a proper tracking by the use of the tracking control signal.

Abstract: In a recording and reproducing apparatus wherein a video signal and an audio signal are recorded on the same recording track, a signal subjected to a quadrature differential PSK modulation with PCM audio signal is generated as an audio recording signal. The audio recording signal is disposed between occupied bands of FM luminance signal and down converted chrominance signal in a video recording signal and also recorded on a track where the video recording signal is to be recorded.

Abstract: A PCM signal recording and reproducing apparatus comprises first and second memory circuits, in which PCM signals are read and written using the first memory circuit, while PCM signals stored in the second memory circuit are error-corrected. At the end of writing by the first memory circuit, the first and second memory circuits are interchanged to read the error-corrected PCM signals stored in the second memory circuit. The read-out error-corrected PCM signals are then recorded on another magnetic tape.

Abstract: When a PCM signal having a sampling frequency of 32 KHz, a quantization of 12 bits per sample, and 4 channel is to be recorded onto tape, the PCM signal undergoes, prior to being recorded onto the tape, such predetermined data dispersion that burst errors incurred in the reproduction operation may be compensated.

Abstract: In a recording operation by a rotary head type PCM recording/reproducing apparatus including at least two magnetic heads, the odd-numbered sample data and the even-numbered sample data are discriminatively extracted and stored. The stored data corresponding to an amount of data outputted from the A/D converter within a predetermined time is selectively read out and supplied to the two heads to thereby record the data in such a manner that the odd-numbered data and the even-numbered data are recorded separately on a track basis or alternatively recorded separately on a preceding half and a succeeding half of each track. The error detecting and correcting code is prepared on the basis of the data to be recorded in each track. In reproduction of the recorded data, upon detection of a drop-out of the data from one of the two heads, the drop-out data is corrected through interpolation procedure to thereby reconstitute the original analog signal.

Abstract: Error detection/correction codes appended to a recording signal for a PCM recorder are so arranged as to ensure detection and/or correction of a dropout or error of a data block address in the reproduction of the recording signal. In recording digital signals on a recording medium, the digital signals are formatted in n-word blocks, each block further including a sync signal for providing a reference timing for the reproduction of the signal, control data related to the digital signals, a data block address for identifying the block of n-words, an error detection code for detecting an error in the control data and the block address, and an error detection/correction code for error detection and/or correction for the block address and the n-words. A recording system includes an error detection/correction code generating circuit which generates error detection/correction codes using a Reed Solomon code or b-adjacent code.

Abstract: This invention relates to an error correction upon reproduction of digital signals. The error correction is performed by decoding code words such as cross-interleaved Reed Solomon codes, in which first code blocks are formed by a plurality of information words which are in the first arrangement state and a plurality of first check words which are produced by codes associated with the plurality of information words with a Hamming distance of d.sub.1, and second code blocks are formed by a plurality of information words and a plurality of first check words which are in the second arrangement state and which consist of the said plurality of information words and the said plurality of first check words which are respectively included in the different first code blocks, and by a plurality of second check words which are produced by codes associated with the plurality of information words and the plurality of first check words with a Hamming distance of d.sub.2.

Abstract: The recording area of the magnetic tape is divided into a first area for recording a PCM converted audio signal and a second area for recording a PCM converted video information. In recording the audio signal and the video information which have been separately PCM converted, the magnetic tape is wrapped around the rotary heads so that a wrap angle of each of said first and second areas is less than 90.degree. with respect to the rotary heads of a predetermined diameter.

Abstract: A method of transmitting a digital signal in the form of successive signal frames containing codes for detecting and correcting errors of the digital signal for reducing degradation in the quality of the reproduced sound due to generation of the code errors in a digitized audio signal transmission system. An analog signal such as an audio signal is sampled and subjected to A/D conversion. The sample word thus obtained is divided into a plurality of symbol elements. Parity words for detecting and correcting code errors are added to every group of a predetermined number of the information symbols through an interleave procedure before being transmitted.

Abstract: Error correction of digital signals is suited for codes having error detection and correction words, such as doubly-encoded Reed-Solomon code. In a first decoding, at least error detection is effected and flags indicating decoding conditions are added. In a second decoding, error detection for first code blocks and error correction for S2 words at unknown locations and E flagged word erasures, where d1 is a Hamming distance and S2 and E satisfy a relation of 2S2+E.ltoreq.d1-1, are parallely or sequentially effected, and a combination of S2 and E having a high correction capability and a low probability of miscorrection is selected from a plurality of correction results of error locations and the numbers of flags added at the first decoding, and the word errors are corrected based on the selected combination.

Abstract: The rotating-head PCM record/reproduce apparatus has record and reproduce heads of which the reproduce heads are disposed to scan the recorded track formed by the record heads with a delay of a rotation angle of 90.degree. thereby reading immediately after recording, and circuits for converting analog signal to digital signal, and for compressing the timebase of the digital signal, the compressed digital signal being supplied to the record heads so that no signal is supplied to the record head while the reproduce heads are reading the recorded signal.

Abstract: A rotary-head PCM data recorder in which PCM signals of m in number, a synchronizing signal, control signals related to the PCM signals, and a parity signal for error detection and correction are formed into data blocks, and data blocks of n in number are recorded on one track of a magnetic tape. Among the control signals, bits of signals common to n data blocks (i.e., information needed once for each track) are formed in distributed data allocated in a group of consecutive blocks or tracks, and multiple block distributive control data are recorded on one track multiple number of times, or multiple track distributive control data are recorded along n block strings a multiple number of times. In reproduction, block or track distributive data are composed to reproduce the control signals. The recorder thus arranged reduces the bit number needed for the control signals and compensates dropout of reproduced data due to scratches on the tape and the like.

Abstract: A digital signal recording/reproducing apparatus capable of recording and reproducing digital signals having differences in respect to sampling frequency thereof and the number of quantization bits per sample by means of a common circuit arrangement includes means for varying revolution speed of rotating heads for recording and reproduction or traveling speed of a recording medium as a function of different sampling frequencies. A signal processing circuit for processing the digital signals so as to be suited for the recording on the recording medium is controlled by a clock signal of which frequency is changed in dependence on the different sampling frequencies. The signal processing circuit is arranged so that PCM data contained in a frame is constituted by a number of bits which is equal to a common multiple of the different quantization bit numbers and added with a common frame synchronizing signal and common error detection and correction codes to thereby prepare the PCM signal of the frame arrangement.

Abstract: A digital-to-analog converter device for PCM signals at different sampling frequencies comprises a signal converter which expands the frequency distance between a PCM signal band and a side band by converting the sampling frequencies associated with the PCM signals to be reproduced into higher frequencies. With this signal converter, a single low-pass filter can be simplified, having a gradual ramp cut-off characteristic for removal of the side band wherein a pass band cut-off frequency and a stop band cut-off frequency can be adapted for low pass filtering of the PCM signals at different sampling frequencies.

Abstract: In a rotary head type digital information signal recording and reproducing apparatus having plural rotary heads mounted on a rotary drum so as to be capable of recording and reproducing signals on parallel, oblique tracks on a magnetic tape, a tracking signal is recorded on at least one portion of each track which is not overlapped with a portion of each track where a digital information signal is recorded to avoid interference between the tracking signal and information signal. The tape travel speed and the rotary drum rotation speed are changed depending upon the transmission rate for a digital information signal to be recorded and reproduced to make the wavelength of a recorded signal frequency constant irrespective of the signal transmission rate. Tracking control is enhanced without increasing the error rate.