Abstract: A television signal format converter is provided for converting without loss of picture information any high definition television format to or from a given recorder/player format. An interface converts between RGB and luminance/chrominance inputs and between analog and digital inputs. The interface couples any proposed high definition television format to a plurality of pairs of memories. A clock and control circuit controls addressing of the memories for reading and writing so that conversion is performed between any high definition television format and the format required for a given high definition digital video tape recorder or any other comparable recorder.

Abstract: In a method of recording digital information signals to form tracks on a magnetic tape, the samples of the signals to be recorded are divided into a plurality of odd sample groups and a plurality of even samples groups. The groups containing adjacent samples are disposed on differently-numbered regions of different tracks. Error correcting codeword may be recorded in a plurality of tracks. Errors in one region can be corrected or compensated by samples in different tracks or samples in differently-numbered regions.

Abstract: A reproducing apparatus of a recording medium, which has address data recorded thereon, a set of data discretely recorded in a plurality of small recording areas thereon, and information indicative of connective relationships between the small recording areas recorded thereon. The reproducing apparatus includes a readout device, a memory, and a controller. The readout device reads data and address data recorded on the recording medium. The memory stores the information indicative of connective relationships between the small recording areas in the data read by the readout device. The controller controls the readout device in high-speed reproduction to repeatedly make an access in accordance with the information stored in the memory and read the data stored in the small recording areas in units of a predetermined data amount.

Abstract: An analog reproduced output can be processed by a digital system circuit in a digital and analog data processing apparatus. An analog output reproduced from a medium on which analog signals are recorded is converted into digital signals by an (A/D) analog to digital converter of a digital recording and reproducing system. These signals are divided signals corresponding to predetermined frequency bands by sub-band filters. The signals are input to a (DSP) digital signal processing section and an (ECC) error correction coding section. An frequency characteristic adjustment operation and an interpolation operation are performed digitally under the control of a controller. Then, for example, the signals are converted by a (D/A) digital to analog converter and output.

Abstract: An apparatus for recording and reproducing a video signal has a recording portion and a reproducing portion. The recording portion has an analog-to-digital converter for converting analog video signal to digital video signal, a wave form data extraction circuit for extracting digital wave form data expressed in 8-bit detail and carried in a vertical blanking period of the video signal, and a converter for converting the digital wave form data to a quantized wave form data expressed in 2-bit detail. The video signal is recorded on a tape together with the quantized wave form data. The reproducing portion has a wave form data selector for selecting the quantized wave form data, a counter converter for converting the 2-bit quantized wave form data to the original digital wave form data of 8-bit detail, and an adder for adding the digital wave form data in a vertical blanking period of the video signal.

Abstract: An apparatus for reproducing digital information from a recording medium having a plurality of parallel tracks and digital information recorded thereon as n-channel (n being an integer greater than or equal to 2) digital signals. The n-channel digital signals are reproduced by n-reproducing heads. The digital information contained in the reproduced signals is stored in a storage device. Discriminating data is obtained for determining which of the n-channel digital signals reproduced correspond to the reproducing heads. The timing of an access device, accessing the storage device for performing a predetermined processing of the digital signals stored in the storage device relative to the reproducing timing of the digital information reproduced by the n reproducing heads, is controlled in accordance with the discrimination data.

Abstract: An electronic method and apparatus for signal encoding and decoding to provide ultra low distortion reproduction of analog signals, while remaining compatible with industry standardized signal playback apparatus not incorporating the decoding features of the invention, and wherein the improved system provides an interplay of gain, slew rate and wave synthesis operations to reduce signal distortions and improve apparent resolution, all under the control of concealed control codes for triggering appropriate decoding signal reconstruction compensation complementing the signal analysis made during encoding. In addition, signals lacking the encoding process features of the invention are likewise compatible with playback decoders which do embody the invention, to provide some overall restoration enhancement.

Abstract: A digital signal processing circuit for processing and recording data at various selectable rates, having an input/output circuit for receiving and outputting a digital signal; a recording circuit for generating a recording signal based on a digital signal received by the data signal processing circuit; a playback circuit for retrieving recorded data; and a demodulation circuit for demodulating retrieved data. The processing and recording rates are determined by control data supplied to the circuit either via an operator or from a recorded signal.

Abstract: Interface apparatus is provided for enabling a digital video recorder to function as a universal data recorder. A random input data stream provided at a first data rate is converted to a format that emulates a video signal. The converted input data is input, at a video signal data rate, to a digital video recorder for storage. The stored converted data is played back from the video recorder at the video signal data rate. The retrieved data is then converted back to the original format of the input data stream at the first data rate.

Abstract: In a digital VTR that carries out magnetic recording and reproduction by bit rate reduction coding a digital video signal, a fixed length block is formed by controlling the code amount of a large block including a plurality of small blocks located distant from each other on a screen at the time of recording. The fixed length block is divided into a plurality of recording blocks so that the main components of respective small blocks are included separately on the recording blocks. The recording blocks are rearranged so that recording blocks including the main components of small blocks adjacent on a screen are also adjacent on a recording medium. Thus, the possibility of deviation in the information amount of each large block is suppressed to improve efficiency of bit rate reduction coding, and to obtain a high speed reproduced picture of high quality.

Abstract: A still picture video signal processing unit 30 and a head unit 40 records video signals of a still picture imaged by a camera unit 10 and PCM audio signals from terminal 2 in a PCM audio area of a magnetic tape 1 as digital signals. A controlling unit 50 controls the still picture video signal processing unit 30 so that an ID for discriminating interchangeability or non-interchangeability of the digital signals may be stored in a predetermined area. During playback, the controlling unit 50 controls the processing unit 30 or the like so that the video signals, the PCM audio signals or the like may be reproduced based on the ID. The user may be informed as to if the recorded digital signals belong to the basic function having interchangeability or to the extension function not having interchangeability and as to the reason playback cannot be made. The producer may be free to add a unique function to make distinction from products of other producers as well as to develop products attractive to customers.

Abstract: A multi-value recorded data detecting method which can achieve accurate detection of multi-value data irrespective of a level variation or an amplitude variation of an input reproduction signal. A reproduction signal from a record medium, on which multi-value data are recorded, is converted from an analog signal into a digital signal in response to a reference clock signal to obtain signal level data. The signal level data are stored into memory means, and distribution information of the signal level data stored in the memory means are found out for each predetermined signal unit. Then, a threshold value or values are set in accordance with the distribution information, and the signal level data from the memory means are compared with the threshold value or values to obtain multi-value data.

Abstract: In a magnetic recording and/or reproducing apparatus, when the reproduced audio data is processed in the reproduction system and the record system and is re-recorded in every cycle of N times the cycle during which the reproducing magnetic head scans a pair of recording tracks, the recording magnetic head is positioned behind the reproducing magnetic head for 8.5+4N track pitch so that the reproduced audio data can be re-recorded on the original recording track, therefor a write-after-read processing can be realized. In the recording magnetic head positioned behind the reproducing magnetic head for the specific track pitch, the audio data is stored in a memory circuit for time base compression and expansion with a multichannel mode such as to record the reproduced audio data at the same part on the magnetic tape, so that a magnetic recording and/or reproducing apparatus which enables to perform the write-after-read processing can be obtained with simple construction if the number of channel is switched.

Abstract: A magnetic recorder/reproducer converts two-channel analog signals into digital signals by a sample-and-hold/A-D converter circuit (3) and controls addresses in a memory circuit (4) by a memory address control circuit (5), to distribute the digital signals into odd sample groups and even sample groups per each channel for arraying the odd sample groups and the even sample groups of the same channel in alternate scanning intervals, thereby to write the same in the memory circuit so that the odd samples and the even samples of the same channel are arrayed in positions separated from each other along the direction of scanning by rotary heads (10, 11). The digital signals thus permutated are modulated by a modulation circuit (7), to be recorded in a magnetic tape by the rotary heads. The digital signals reproduced by the rotary heads are demodulated by a demodulation circuit (14), to be stored in a memory circuit (15).

Abstract: Digital video signal of one frame is converted to macro blocks which are arranged in a predetermined order in one rectangular block. The macro blocks are converted to synchronizing block data and are recorded in a predetermined number of tracks of a magnetic tape. In high speed reproducing operation, a tape running speed is selected to a reference speed at which scanning areas of the tracks of successive frames having the same track number are shifted in a direction every frame number, and video data which are on every other frame are arranged on the reproduced video image.

Abstract: Method and apparatus for recording a plurality of audio channels on segmented tracks of a tape by rotary heads. The audio channels to be recorded are allocated to recording sectors provided for the individual audio channels on the basis of the relation between the number of the audio channels and the number of the segmented tracks, so that each recording track necessarily includes the individual audio channel recording sectors uniformly distributed in the longitudinal direction of the tape, and the two-dimensional distance between the sectors on which the same audio channel is recorded can be maximized on the tape. Thus, an adverse effect of an error attributable to a dropout and/or a scar formed on the tape can be dispersed, thereby achieving high capability for error correction.

Abstract: A video compression/expansion apparatus for a digital VCR, having an analog/digital converter, a memory, a video compression/expansion device, a compressed data memory, a modem, an error corrector, a deformatter, a first buffer, a second buffer and a digital/analog converter sequentially connected and electrically coupled to one another.

Abstract: An apparatus and method for preparing a variable-rate coded signal, generated by compressing a digital input signal using a variable compression ratio and including a signal portion of a predetermined type, for recording on a recording medium. In the apparatus, a circuit generates a flag signal indicating the signal portion of the a predetermined type in the variable-rate coded signal. A signal-type marker generating circuit generates a signal-type marker in response to the flag signal. Finally, a circuit multiplexes the signal-type marker with the variable-rate coded signal to produce a multiplexed signal for recording on the recording medium. The signal-type marker is located adjacent to the signal portion of the predetermined type to indicate the signal portion of the predetermined type in the multiplexed signal.

Abstract: A method of recording a sequence of video blocks, each comprising a plurality of bytes, each representing compressed image data code, includes the step of recording a video block identification signal after recording a synchronization signal in each of a plurality sync blocks. Then video data codes are recorded adjacent the video block identification signal. This is followed by a connection code being recorded adjacent the video data codes in the video blocks. The video block identification signal recorded between the synchronization signal and the video data codes contains a coded combination of bits for defining the position of first bit or byte of a new video block in the video data area.

Abstract: A karaoke apparatus for medley playback includes: playback unit for receiving playback information including MIDI sound source control information and producing acoustic sound of karaoke song on the basis of the playback information; information storage unit for storing playback information and identification information of a plurality of karaoke songs, the identification information specifying playback information of a highlight portion of each of the plurality of karaoke songs; selection instructing unit for instructing a selection of karaoke songs to be played; and playback control unit for reading out playback information of the highlight portions of the songs selected by the selection instructing unit from the information storage unit on the basis of the identification information of the each of the selected karaoke songs, and controlling the playback unit to successively play the selected karaoke songs on the basis of the playback information of the selected karaoke songs to produce a medley of the sele

Abstract: Systems, apparatus and methods for recording or reproducing from a re-recordable record carrier digital signals, representing a digital audio signal, containing information which results in concealment of a portion of a replica of the digital audio signal during its reproduction to prohibit audio distortions resulting from a boundary between two digital signals, wherein one of those digital signal is newly-recorded over a previously-recorded other digital signal. The concealment information can also be included in auxiliary signals recorded on reproduced from the record carrier along with the digital signals. In a recording apparatus, a digital signal including audio information (i.e.

Abstract: A band compression signal processor designed to convert video signals or the like into digital signals and to perform band compression by effecting both intra-frame encoding and inter-frame encoding. The signal output by the processor is supplied to a recording/reproducing apparatus. In the apparatus, the signal is recorded on a magnetic tape and reproduced therefrom by helical scanning method. The signal intra-frame-encoded is arranged within such a region as to be read out in fast reproduction mode.

Abstract: An apparatus and method have been conceived for using a digital audio tape (DAT) in an audio logger for the purposes of storing and retrieving audio data. This is accomplished in a manner such that the data is received and recorded in a time related manner. Provision is made for accommodating the transfer drive rate of the DAT through use of a buffer between the signal processor of the logger and the DAT. In addition, the method of storing the data results in greater use of the available space on the DAT as the DAT tape only writes for those periods when audio is present on a channel.

Abstract: A signal characteristic variation apparatus for a high definition VCR in which a characteristic of a video signal is varied according to characteristics of a tape and a channel. A predetermined frequency band of test signal is recorded on the tape for recording the tape and channel characteristics in a recording mode. This enables the video signal to be recorded on the tape in the proper mode and permits, in the play-back mode, the tape and channel characteristics to be discriminated by detecting the test signal recorded on the tape. Therefore, the video signal can be played back from the tape with its frequency characteristic properly adjusted according to the discriminated tape and channel characteristics.

Abstract: A signal processing method for recording and playing back recorded data with decreased detection errors originating from residual marks characteristic of an overwrite medium is performed by 8/9 modulating input data, and by inverting the polarity of the modulated data string at each "1" bit to produce a DC-free recording pulse. The thus-recorded signal is played back through a playback equalizer 8 before being converted by an A/D converter 9 into digitized amplitude data. The digitized data are processed to determine an identification level, which identification level is stored as well as used to determine displacement quantities for quantized bits derived from the analog playback signal. The number of "1" bits is counted by a counter 20, and an error in the number of "1" bits is detected by a comparator 21.

Abstract: A signal processing apparatus for recording an audio input signal on a recording medium by time base compressing the signal or reproducing the signal from the recording medium is arranged to limit the high band of the audio input signal before compressing the time base thereof and to control the low band cut-off frequency or the degree of suppressing the low band of the signal according to the high band cut-off frequency thereof.

Abstract: In an information processor, code errors in a compressed information code train with an added error correction code are corrected using the error correction code. The error corrected compressed information code train is decoded using decoding corresponding to the compression encoding and an information code included in the information code train that is uncorrectable using the error correction code is produced. The compressed information code train inputted to the decoder and the produced information code train are output. The outputted produced information code train is converted into analog data which is output.

Abstract: Apparatus and method for asynchronous gain adjustment are provided for data detection in a partial-response maximum-likelihood (PRML) data channel. The PRML data channel includes an analog to digital converter (ADC) having a normal operating range and a filter, gain and timing control coupled to the ADC. A plurality of samples are detected from the ADC. Each of the detected samples are sequentially compared with predetermined threshold values. The predetermined threshold values include a zero value, and a minimum value and a maximum value of the normal operating range of the ADC. An absolute value of each of the detected samples are sequentially compared with a forth predetermined threshold value. A gain adjustment correction value is determined utilizing the sequentially compared values.

Abstract: A digital video/audio recording and reproducing apparatus comprising a video signal high-efficiency encoder having a variable reduction rate, an audio signal high-efficiency encoder having a variable reduction rate, and a controller for controlling the reduction rates in both of the high-efficiency encoders. The reduction rates in both of the high-efficiency encoders are controlled in such a manner that the sum of the information amount of the video signal and that of the audio signal, after high-efficiency encoding, is maintained constant. When recording multi-channel audio signals, the reduction rates in both of the high-efficiency encoders are controlled according to the number of audio signal channels to be recorded. The high frequency components of the high-efficiency encoded video and audio signals are recorded at the end portions of recording tracks on a magnetic tape, while the low frequency components thereof are recorded in the central portion of the recording tracks.

Abstract: A video signal mixing apparatus for mixing a playback composite video signal produced by playing a recording medium and a graphics composite video signal generated on the basis of video data read from a memory device, wherein a vertical synchronizing signal of the playback composite video signal is forcedly generated in response to a vertical synchronizing signal of the graphics composite video signal to make the number of horizontal scanning lines of the playback composite video signal coincident with the number of horizontal scanning lines of the graphics composite video signal.

Abstract: In a digital information signal transferring apparatus for transferring sequential sync block data composed of encoded synchronous, ID and digital information signals, the digital information signal is encoded and an insertion area is formed therein, whereupon, an ID signal is added in the insertion area and comprises a format identifying signal, a signal for identifying the type of the digital information signal, and a sync block number.

Abstract: A digital video recording system for digitizing analog video signals and recording the digital signals on video tape and for reading digital video signals from video tape and producing an analog video signal. The recording system comprises an A/D converter, a data compressor for compressing digital video signals at a data rate of 1/N (N an integer greater than 1), an encoding and modulating mechanism that provides digital data segments, and a control mechanism for controlling the system such that recording data for one field, which is normally recorded in M tracks (M: an integer greater than N) in ordinary recording mode, is recorded in about M/N tracks in a long recording mode.

Abstract: A data backup apparatus for temporarily storing the data stored in a volatile memory using an internal battery when the main power is stopped. When the operation of the internal battery is started, the data stored in the volatile memory as a digital signal is converted into an analog signal by a D/A converter, and then it is stored in a magnetic storage unit. When the power supply is restored, the data stored in the magnetic storage unit as the analog signal is read out and converted into the digital signal, and then it is restored to the volatile memory.

Abstract: A video signal recording apparatus has a high band signal recording circuit for deeply recording onto a recording medium a high band component of a video signal separated from a composite video signal and a low band signal recording circuit for recording on a recording medium a low band component of a signal separated from the composite video signal using a much shallower recording depth.

Abstract: Timing loop apparatus and method are provided for data detection in a partial-response maximum-likelihood (PRML) data channel. The PRML data channel includes an analog to digital converter (ADC) providing samples to a digital filter during a tracking mode and to a gain and timing control during an acquisition mode. Sample values from the ADC are received at peaks and zeros on sync field pattern. An error absolute value is calculated from the received ADC sample values and an error sign of the calculated error absolute valve calculated using a most significant bit of the current and a previous sample. Timing correction values are calculated responsive to the calculated error absolute value and applied to a clock gated register that latches and holds the generated timing correction values for a predefined number of clock cycles.

Abstract: An apparatus for generating a high speed dubbing signal to be recorded by an external recording apparatus. The high speed dubbing signal, whose pitch is N times that of a digital input signal, is generated as follows. An encoding circuit subsamples the digital input signal consisting of frame signals each of which consists of N field signals, so that each frame signal is compressed by a factor of N to be contained in one field interval. A digital signal recording and reproducing circuit including a recording and reproduction system, records on a tape, at a normal tape speed and at a normal head drum rotational frequency, the compressed signal in such a manner that each field including the compressed signal appears once per frame interval, and then selectively reproduces from the tape the field including the compressed signal at a tape speed N times the normal speed and at the normal drum speed.

Abstract: A recording/reproducing apparatus in which the number of revolutions of a recording head 14 is controlled depending on the frequency of the vertical synchronization signals for picture signals supplied from outside for digitally recording/reproducing picture data. It is not the recording head 14 but the playback head 16 whose number of revolutions is controlled in such manner during reproduction. In forming DRCK control signals employed for controlling the number of revolutions of the recording head, the frequency of the vertical synchronization signals for the picture signals supplied from outside is corrected so as to be within a range of offset of .+-.1% relative to the frequency of standard frequency vertical synchronization signals, and the DRCK control signals are formed based upon the vertical synchronization signals corrected in this manner.

Abstract: Compressed digital data obtained by compressing digital input data by, for example, a compression ratio of four, which reduces the amount of data to one fourth of the original amount, is recorded on a magneto-optical disk or other recording medium. The block of compressed data resulting from compressing one block of the input data is recorded on the disc in a time in a fraction (one fourth in the example) of the real time duration of the input data. In the remaining time, the block of recorded data is read out from the disc in the next fraction of the real time duration of the block of input data. The read out block of compressed data is compared with the block of compressed data, and, when the read out block of compressed data does not match the block of compressed data, the same block of compressed data is again recorded in the same place on the disk in the next fraction of the real time duration of the block of input data.

Abstract: In a digital signal reproducing apparatus various adjustment jobs and measurement jobs can be automatically executed by a simple operation by providing a clock generator, an external waveform equalizer, an error detector, an edge detection circuit, and a DC following circuit in addition to a waveform equalizer by which a reproduced analog signal waveform is processed and then converted to a digital signal. The digital signal is equalized by a digital filter and sampled and the digital signal and extracted clocks are supplied. The reproducing level and the equalizer coefficients can be automatically adjusted and an error rate can be automatically measured. A pulse width modulation or bias recording can be automatically determined and a recording current can be automatically adjusted by the system and the inclination of magnetic heads and the distance between the heads can also be automatically measured.

Abstract: A data tape recorder having a data compressor/expander for recording digital information on a magnetic recording tape and for reproducing it therefrom. In a digital audio tape recorder having a 4-head deck each provided with two recording heads and two reproducing heads, a switching pulse interval is channel-counted to a multichannel interval, and if the channel count signal and a channel selection signal by user are identical, only a reproducing signal of the selection channel among the signals being reproduced from the reproducing heads is expanded and reproduced. Moreover, in order to record data to a corresponding channel, the expanded reproducing data and compressed input data are multiplexed by the channel selection signal. Thus, the record/reproduction of a multichannel for a long time is possible.

Abstract: A digital VTR is provided for recording data for one-frame of video and audio signals, which have been error-correcting-encoded collectively, in a predetermined number of pieces of tracks during normal recording and for recording data for the video and audio signals, which have been error-correcting-encoded collectively, in one less than the predetermined number of tracks and data for the audio signal, which have been error-correcting-encoded during post-scoring, in the remaining one track exclusively for the post-scoring during post-scoring audio recording.

Abstract: A reproduction signal processing apparatus includes a memory circuit storing a predetermined pattern for deciding equalizing characteristics of an automatic equalizer in response to variation of a reproduction signal, a pattern converting circuit for converting the predetermined pattern outputted from the memory circuit into an equalization target pattern serving as a target of the equalization and correction by the automatic equalizer, an equalization error calculating circuit for producing an equalization error from the equalization target pattern and the equalization signal outputted from the automatic equalizer, and the automatic equalizer executing a partial response waveform process of the reproduction signal on the basis of the equalization error, for correcting the predetermined equalizing characteristics of the automatic equalizer by tracing the fluctuation of the reproduction signal.

Abstract: A digital audio reproduction system for compact discs, digital audio tapes and other similar systems suppresses digital noise present in the frequency band immediately above the audio band. Digital preprocessing combined with narrow output filters result in significant noise suppression without adverse distortion of the desired audio signal. The digital preprocessor may be combined with digital oversampling filters into a single integrated circuit or microprocessor.

Abstract: This invention relates to a device for correct converting of continuously reproduced serial data to original parallel data by detecting a synchronous signal, including a shift register for delaying serial data by a number of bits of a synchronous signal pattern in accordance with a serial clock, the serial data being reproduced from a magnetic recording medium, a detector for detecting a synchronous signal from an output signal of the shift register, a system controller for generating a predetermined bits interval of a parallel load signal and a parallel clock signal from the synchronous signal in accordance with the serial clock, a parallel shift register for converting the output signal of the shift register to a predetermined bits interval of parallel data in accordance with the parallel load signal, and counter part for counting the parallel clock signal to generate window signals detecting the synchronous signal in a certain period when the detector detects the synchronous signal.

Abstract: Apparatus and method for storing and retrieving audio data simultaneously. A digital audio logger is provided with a digital audio tape (DAT) for permanent storage of audio data and with a random access storage (RAS) device that provides fast retrieval of audio. Both the DAT and RAS devices have audio written from a buffer that initially stores audio data temporarily. Two pointers are provided for the RAS device. Because of the randomness characteristic of the RAS device, data can be retrieved rapidly with a first one of the pointers and for this reason has advantages in fast retrieval. The RAS device communicates with a supervisor whereby data can be retrieved therefrom through the first pointer while the RAS device is receiving data from the buffer through the second pointer.

Abstract: When the low bit rate coding is effected in a recording system 1A, a signal is coded and recorded in a hierarchical structure. On the reproduction side, the type of a recorded signal (the low bit rate coded signal of the hierarchical structure, non-hierarchical structure, conventional analog recording or the like) is determined by a determination system 1E and the operation modes of a digital signal processing system 1G and an analog signal processing system 1F are set. The analog signal processing system processes a reproduced signal when it is analog signal. The digital signal processing system processes a reproduced signal when it is a digital signal or when a reproduced output from the analog signal processing system is processed in a digital manner.

Abstract: A video signal recording apparatus is provided with first and second channels for transmitting an input video signal. The first channel has a line memory for conducting a 1H delay on data and a time-base-extension line memory for conducting time base extension on the data with the 1H delay. The data subjected to the time base extension undergoes D/A conversion to be an output of the first channel. On the other hand, the second channel does not have a line memory for a 1H delay, and the video signal without delay is subjected to time base extension and undergoes D/A conversion to be an output of the second channel. In the arrangement, odd lines and even lines respectively contained in adjoining two frames in each channel are reversed such that in a certain frame, odd lines of the input video signal are transmitted through the first channel with even lines through the second channel. In the next frame, even lines are transmitted through the first channel with odd lines through the second channel.

Abstract: A method of recording/reproducing a table of contents in a digital magnetic tape apparatus, in which a head performs a helical scan of a magnetic tape to obtain tracks, each track including a PCM area for recording digital data and a subarea for recording subcode signals. In the recording, a reproduction skip signal is written in the subarea by a TOC button operation and a TOC signal is written in the PCM area of the tape itself as an audio signal. Also, a TOC code signal corresponding to the TOC signal is written in the subarea. When reproducing, the TOC code signal is stored in a program memory during the reproduction of the tape. A high speed search of program numbers or music titles and a data head position searching of the same are precisely performed.

Abstract: A disk apparatus having a readout circuit for providing readout data signals and capable of immediately detecting runaway of a readout clock signal generated from a VFO (Variable Frequency Oscillator) in the readout circuit if such occurs. The disk apparatus is free from a read error due to a permanent defect on a disk, e.g., an optical disk, or other causes. The disk apparatus includes a head for picking up signals from a disk, and a readout circuit for providing a readout signal and a readout clock signal, including a digitizing circuit for receiving and digitizing a data signal picked up by the head into a binary data signal, a reference clock generator for generating a reference clock signal and a variable frequency oscillator for receiving a read-gate signal, the digitized binary data signal and the reference clock signal and generating a readout data signal and a readout clock signal, each synchronized with the reference clock signal.

Abstract: Specified modular arithmetic is applied to input digital data to divide the input data into two main codes and a subcode. Otherwise, input digital data is divided into two pieces of digital data according to a specified rule. The digital data is divided so that the original input digital data can be completely restored if the two main codes and the subcode or both of the divided data are used, and the original input digital data can be nearly correctly restored even when one of the main codes or one of the divided data is used.