Abstract: Rotary head recording and/or reproducing apparatus in which respective oblique tracks on a record medium are scanned, each track having an information signal area in which information data is recorded and a track following area in which a tracking control pilot signal is recorded. The track following area precedes the information signal area; and in the preferred embodiment, an additional track following area follows the information signal area. The pilot signal is recorded in only a portion of the track following area, the remainder of which has timing sync data recorded therein. In an after-recording mode the timing sync data is reproduced, detected and used as a reference to define an after-record area.

Abstract: In a digital video tape recorder that has rotary magnetic heads for recording digital video information on a magnetic tape in the form of data blocks having a predetermined length, an ID signal is generated for each data block. The ID signal includes a number of data bits which identify the address of the data block, the information contained in the data block, and so forth. For the purpose of generating error code parity symbols, the ID signal is divided into a sequence of four-bit symbols, and at least two parity symbols are generated according to an error correction code for correcting errors in the sequence of four-bit symbols. The ID signal and parity symbols are recorded together on the magnetic tape. In this way, error correction can be performed on the ID signal during reproduction.

Abstract: Respective regenerative signals from magnetic heads 1A, 1B are combined into one system through a changeover switch 9. After the reproducing characteristic is compensated by using a filter 4 serving as an equalizer, that combined signal is decoded at a decoder 5. An adaptive control unit 7 adjusts (modifies) the characteristic of the filter 4 so that it becomes optimum on the basis of a decode error (residual) at the decoder 5 and an input to the filter 4. The adaptive control unit 7 carries out an adaptive processing in a time divisional manner for every regenerative signal of respective magnetic heads 1A, 1B to send filter coefficients for the respective magnetic heads 1A, 1B to the filter 4. Thus, since the adaptive processing is carried out in a time divisional manner by the filter 4 and the adaptive control unit 7, the circuit scale can be reduced, resulting in low cost.

Abstract: A VTR has heads adapted for reading out a video signal, a PCM audio signal, and an FM audio signal, respectively, from a magnetic tape, and a signal detecting circuit operable to detect which of the video, PCM and FM signals are recorded on the magnetic tape and to provide a signal indicative thereof to a system control circuit which controls a switching circuit for selectively connecting FM and PCM audio demodulating circuits with a signal output line, so that the video signal and the PCM audio signal or the video signal and the FM audio signal are output to be reproduced. The VTR further includes a recording system adapted to record a video signal, a PCM audio signal, and an FM audio signal in respective magnetic layers of a magnetic tape which are at different depths relative to the surface of the magnetic tape in accordance with a predetermined recording current relationship used for recording the video, FM audio and PCM audio signals so as to improve the S/N ratio of each signal when reproduced.

Abstract: A magnetic recording and/or reproducing device uses a Viterbi decoding circuit wherein, when data falls within a predetermined range, the level of the reproduced signal is sensed and the level of the reproduced signal is corrected in a manner which reduces bit error caused by noise in the reproduced signal. Alternatively, the value of a previous video signal value is corrected in accordance with the amount of change in an instant signal value.

Abstract: In an apparatus for detecting input digital data, for example, as derived by analog-to-digital conversion of a reproduced binary signal in analog form; a distributor circuit distributes the input digital data into at least two channels, a processing circuit in each channel processes the respective digital data in accordance with a predetermined formula, a decoder in each channel decodes an output of the respective processing circuit in accordance with the Viterbi algorithm, and the outputs of the decoders are composed or combined to provide therefrom a single sequence of digital data.

Abstract: A digital signal processing apparatus adapted for use in a digital video tape recorder or the like. The apparatus includes a digital multiplexer for combing an input digital information signal and an input digital pilot signal with each other on a predetermined time basis so as to produce a composite recording signal; and a variable gain amplifier supplied with the composite recording signal of the digital multiplexer for amplifying at least one of the digital information signal and the digital pilot signal in the composite recording signal to respective different levels. With a relatively simple circuit configuration and a control action which operates in a relatively straight-forward manner, a relatively high operational reliability is achieved.

Abstract: In a digital signal reproducing apparatus for detecting identifying data in a reproduced digital data signal which had been recorded on slant tracks formed sequentially on a magnetic tape by a rotary head and which is reproduced at a speed higher than a normal playback speed, a synchronizing detector circuit detects synchronizing data included in the reproduced digital signal and, in response thereto, a pulse signal is generated and supplied to an identifying data detector circuit which, in response to such pulse signal, receives a plurality of corresponding identifying data. The identifying data detector circuit determines the identifying data value which corresponds to the majority of the received plurality of identifying data.

Abstract: In a playback phase correction apparatus for a video recorder, a signal level of an input signal is compared with predetermined reference levels at times according to a playback clock signal. The apparatus operates to continuously detect whether the phase of the playback clock approaches or recedes from a point in time at which the eye pattern of the input signal is at a maximum value by comparing a count value obtained from the comparison results of the reference level counts from a previous cycle with those of the current cycle. Then, the apparatus controls a playback clock delay circuit on the basis of these count values so than an optimal count value is continuously maintained, thus ensuring that the timing of the playback clock is maintained in synchronization with the maximum eye pattern interval of the input signal.

Abstract: A digital signal reproducing apparatus wherein an analog signal corresponding to stored digital data is processed to generate a digital data signal including an analog-to-digital converter operative to convert the analog signal to a digital signal, a decoder to decode the digital signal, and a memory interposed between the analog-to-digital converter and digital decoder to remove time base components from the digital signal. The analog signal is converted to the digital signal and the digital signal is read into the memory at a first clock rate. The digital signal is read out from the memory and subsequently decoded at a second clock rate.

Abstract: Apparatus for regenerating a coded digital signal, comprising an interference cancellation equalizer for cancelling an interference component from an input digital signal and a decoder. The equalizer includes a compensator for high frequency compensating the input digital signal, an extractor for extracting intercode interference from the compensated digital signal, and a subtracter for subtracting the extracted intercode interference from the input digital signal to produce a waveform equalized signal. The decoder recovers the original digital signal as a function of the correlation or samples of the waveform equalized signal.

Abstract: An apparatus for decoding a transmitted signal has a receiver for receiving the transmitted signal, a filter for limiting the frequency of the output of the receiver below a predetermined frequency, a generator for generating a clock signal having a frequency equal to a transmitting rate of the signal output from the receiver, a converter for sampling the output of the filter at a frequency defined by the clock signal and for converting the filter output into a binary signal, and a processor for decoding the binary signal according to a predetermined system.

Abstract: A digital recording and reproducing system for ME tape uses a class 4 partial-response encoder in the recording apparatus and a corresponding decoder in the reproducing apparatus. A high signal-to-noise ratio is achieved without the need for a phase equalizer.