JPH0440655A - Digital signal recording/reproducing device - Google Patents

Abstract

PURPOSE:To make it possible to repeatedly change an erasing position or an erasing interval by providing the digital signal recording/reproducing device with a circuit for muting a main signal to be reproduced at timing specified by a subsignal reproduced from a recording medium. CONSTITUTION:In the case of executing spot erasing for erasing a part of voice data record on a tape, timing information indicating the start and end of muting is written only in a subsignal area by post recording and at the time of reproducing, the muting information is read out from the subsignal area and a main signal is muted in accordance with the read muting information. In the case of correcting a muting position or muting interval, only the muting information of the subsignal area is rewritten by post-recording. In the case of executing so-called spot erasing for partially erasing the contents of the tape recording voice or the like, erasing information is written in the subsignal without directly erasing the main signal, so that after executing the erasing operation, the main signal such as original voice can be restored and the erasing position or the erasing interval can be repeatedly changed.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a digital signal recording and reproducing apparatus that converts audio and the like into digital signals, records them on a recording medium, and reproduces them.

(Prior Art) In recent years, so-called digital audio technology, which converts analog signals such as audio signals into digital signals and records and reproduces them, has made remarkable progress. For example, a PCM processor using a VTR mechanism and tape, a compact disk, and more recently a rotary head type digital audio tape recorder (hereinafter referred to as R-DAT) have come on the market. For R-DAT, DIGIT
AL AIJ-DIOTAPE RECORDERSY
STEM, The DAT Conference.

6 and below, which are explained in detail in June, 1987.
This will be explained using R-DAT as an example.

For example, when recording music with R-DAT, it is recorded according to the track format and block format shown in FIGS. 3 and 4. In this case, as sub-signals, time codes such as program time, absolute time, running time, characters, etc. are grouped into groups called packs and recorded in the sub-signal area. Furthermore, signals indicating the beginning of a song, signals indicating the song number, etc. are also recorded as sub-signals.

The recording track on the magnetic tape is 1 as shown in Figure 3.
Since the track consists of 196 blocks and is divided into a sub signal area and a main signal area, only individual areas can be rewritten later by after-recording (hereinafter referred to as dubbing).

(Problem to be Solved by the Invention) However, when performing spora erase to erase a part of the audio data recorded on the tape with the above-mentioned R-DAT etc., if the -degree erase operation is performed, Since the main signal is actually rewritten, the previous main signal cannot be restored even if one wants to change the erased position later, so there is a problem that the erased position cannot be changed.

In view of the above-mentioned problems, the present invention has been developed using a method called Spola Erase, which is also used when partially erasing a tape on which audio etc. have been recorded.
The main signal is not directly erased, but erasing information is written to the sub signal, and even after performing the main erasing operation, the main signal such as the original audio can be restored, and the erasing position and erasing interval can be changed any number of times. The purpose of the present invention is to provide a digital signal reproducing device.

(Means for Solving the Problems) A digital signal recording/reproducing apparatus of the present invention includes a recording/reproducing circuit for a main signal and a sub-signal, and a circuit for muting the main signal at a timing specified by the sub-signal.

(Function) With the above-described configuration, the present invention writes mute start and end timing information only in the sub-signal area during post-recording when performing spora erase to erase part of audio data recorded on a tape. During playback, mute information is read from this sub-signal area and the main signal is muted accordingly. If you want to modify the mute position or mute interval, you can do so by rewriting only the mute information in the sub signal area during dubbing.

(Example) An example of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of a recording/reproducing circuit of an R-DAT which is an embodiment of the present invention. In FIG. 1, 1 is a recording medium, and in this embodiment, a magnetic tape is used.

2 is a rotating cylinder to which a recording/reproducing head is attached; 3
is a recording amplifier, 4 is a reproduction amplifier and equalizer, 5 is a signal processing circuit, 6 is an A/D converter, 7 is a D/A converter,
8 is a system control microcomputer, 9 is a mute circuit, a is an audio signal input terminal, b is an audio signal output terminal, and C is an erase button.

The operation of the digital signal recording/reproducing apparatus of this embodiment configured as described above will be explained below.

A previously recorded tape is played back, a playback signal is obtained from the magnetic tape 1 by the magnetic head, and after amplification and waveform shaping by the playback amplifier and equalizer 4, demodulation, error correction, etc. are performed in the signal processing circuit 5, and the main Signal and sub-signal are output. The main signal is converted into an audio signal by a D/A converter 7 and output to an audio signal output terminal.

While monitoring this reproduced sound, the operator presses the erase button when he/she recognizes that the position to be erased is reached. At this time, playback from the tape continues and a playback audio signal is continuously obtained from the audio signal output terminal, but the system control microcomputer stores the time code at the timing of the press in an internal memory or the like as an erasure start point. When the erase button is further released, this timing is also stored as the erase end point and reproduction is stopped. Thereafter, while playing back the sub signal, the tape is rewound to several frames before the start of erasing, and dubbing of the sub signal is started. For example, as shown in Figure 2, as mute information, the time code of the erasure start point and end point, the erasure start and end information are used as the erasure start point background, the erasure end point background, and the start point background. is recorded in only a few frames before and after the start point, and the back for the end point is written in the sub-signal area so that it is recorded only in a few frames before and after the end point. Alternatively, both backs may be continuously recorded from several frames before the erasure start point to several frames after the erasure end point. When reproducing a tape on which a sub-signal of mute information is recorded in this way, the system control microcomputer 8 can obtain the mute start information from the sub-signal several frames before the desired mute start position. The system control microcomputer 8 stores this information in internal memory, etc.
Compare with the time code played back from the tape. When the two match, a start instruction is given to the mute circuit. The mute circuit is, for example, 74H of a CMO8 general-purpose logic IC.
Using an AND gate such as C8, a digital audio signal is applied to one input, and a mute signal from the system control microcomputer 8 is applied to the other input. If the mute signal is at n level, a digital audio signal is output to the output of the AND gate, but
If the mute signal is at n level, the output of the AND gate is fixed to L and muting is applied.

Alternatively, a selector with two inputs and one output, such as the CMO8 general-purpose logic IC 74HC157, may be used to switch the digital audio signal to a digital signal prepared in advance in a memory or the like, or a digital signal applied from the outside in response to a mute start instruction. . Ending mute can also be achieved by performing similar processing.

When changing the mute position, only the mute start point pack and mute end point pack need to be rewritten by dubbing.

As described above, according to this embodiment, mute start and end timing information is written only in the sub signal area during dubbing, and during playback, mute information is read from this sub signal area, and the main signal is muted accordingly. Providing a mute circuit to do this ↓This makes it possible to restore the original audio and other main signals even after the erasing operation, even when erasing parts of a tape on which audio has been recorded. You can change the erasing interval as many times as you like.

(Effects of the Invention) According to the present invention, a main signal obtained by converting a signal such as an audio signal into a digital signal, and a recording/reproducing circuit that records and reproduces a secondary sub-signal accompanying the main signal onto a recording medium, and a sub-signal reproduced from the recording medium. By providing a circuit that mutes the main signal to be played back at the timing specified by can be restored, and the erasing position and erasing interval can be changed any number of times, which has great practical effects.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of the recording/reproducing circuit of R-DAT according to an embodiment of the present invention, FIG. 2 is a diagram showing the position where mute information is recorded, and FIG. 3 is a track format diagram of R-DAT. FIG. 4 is a track format diagram of R-DAT. 1...Magnetic tape, 2...Rotating cylinder. 3... Recording amplifier, 4... Playback amplifier equalizer,
5... Signal processing circuit, 6... A/D converter,
7...D/A converter, 8...System control microcomputer, 9...Mute circuit, a...Audio signal input terminal, b
...Audio signal output terminal, C...Delete button. or

Claims (1)

[Claims] A circuit that records and reproduces a main signal obtained by converting an analog signal such as music into a digital signal and ancillary sub-signals accompanying it on a recording medium, and a timing specified by the sub-signal reproduced from the recording medium, A digital signal recording and reproducing device characterized by comprising a circuit for muting a main signal to be reproduced.