Abstract: A PCM digital audio signal playback apparatus is provided for extracting from the digital audio signal read out from a recording medium an original signal component ranging lower than 1/2 of its sampling frequency fs, producing a harmonic from the original signal component, extracting a harmonic component ranging higher than fs/2 from the harmonic, and adding the harmonic component to the original signal component. Accordingly, a high-frequency carrying signal, e.g. an impulse, is processed without causing ringings in the waveform response.

Abstract: A method for performing a reproduction and search operation on a data recording and reproducing device of the helical scan type which includes a pair of recording and reproducing heads mounted on a rotary drum. The method includes the steps of: (a) during the reproduction operation, transporting the tape and rotating the rotary drum such that a relative speed between said tape and the heads is either a first relative speed or a second relative speed which is less than the first relative speed; and (b) during the search operation, transporting the tape at a speed substantially greater than a tape speed used during the reproduction operation and rotating the rotary drum at a speed such that a relative speed between the tape and the heads is equal to the second lower relative speed.

Abstract: In a stereo sound digital recording system in which a plurality of tunes or programs are sequentially and digitally recorded on a magnetic tape, the left and right analog input signals are combined and converted to a digital signal. The analog input signals are also applied to a detector which detects the head of the program or tune and which causes to be generated a start identification sub-code signal which is automatically added to the digital signal, before the modulation thereof, and which is recorded on the tape for about nine seconds in the non-sound portion preceding the tune or program. A second sub-code signal, in the form of a program number signal, may also be added to the digital signal, simultaneously with the program start identification sub-code signal, to provide recorded numbers respectively identifying programs which are sequentially recorded on the tape.

Abstract: A tape recorder may be provided with a memory which stores data regarding the unrecorded portion remaining on each of a plurality of recording tapes. The data may represent an amount of the unrecorded portion and/or the location thereof, e.g., in the form of a counter value. The data stored in the memory is displayed in response to an input from an operating panel, thus making it possible to readily identify a tape having a remaining time equal to or greater than the quantity of information to be recorded, and to quickly advance the tape to the beginning of its unrecorded portion.

Abstract: An apparatus for recording and reproducing digital signals using a helical scan in which a drum of reduced diameter is employed without changing the tape format. Two heads are mounted on a drum at the same height in opposition to each other with a product of the diameter D of the drum and the wrap-around angle of the tape with respect to the rotary drum being constant while the speed of the drum is increased to a speed N times higher than a predetermined speed. One of the heads is mounted higher than the other by a distance of (1-1/N)P to provide a step, and the other head being is mounted at a position an angle behind the position at which the other head directly opposes the one of the heads, which angle is defined by: ##EQU1## where L is the track length in the tape format used when the rotary drum rotates at the predetermined rotational speed, .THETA. is the track angle, P is the track pitch, and C is a constant dependent on the drum diameter D and the wrap-around angle.

Abstract: In a digital audio recording/reproducing apparatus of the rotary head type, erasure of signals in previously recorded tracks, which are used to control the operation of a tracking servomotor, is enhanced by the provision of a magnetic field generator prior to the point where overwriting occurs. As a result, errors in the tracking error signal arising due to unerased remnants of the previously recorded signals are eliminated.