JP2681836B2 - Digital signal recording / reproducing device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a digital signal recording / reproducing apparatus for converting voice or the like into a digital signal and recording / reproducing it on a recording medium.

(Prior Art) In recent years, so-called digital audio technology, in which an analog signal such as a voice signal is converted into a digital signal and recorded and reproduced, is remarkable. For example, VTR mechanism and PCM processor using tape, compact disc,
More recently, a rotary head type digital audio tape recorder (hereinafter referred to as R-DAT) has been put on the market. For R-DAT, DIGITAL AUDIO TAP
It is described in detail in E RECORDER SYSTEM, The DAT Conference, June, 1987.

Hereinafter, the R-DAT will be described as an example. When recording music, for example, with the R-DAT, the music is recorded according to the track format and block format as shown in FIGS. In this case, time codes such as program time, absolute time, and running time as sub signals, and characters are recorded in the sub signal area in groups called packs. Also, a signal indicating the beginning of a song, a signal indicating the song number, etc. are recorded as sub-signals.

The recording track on the magnetic tape is as shown in FIG.
Since one track is composed 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).

(Problems to be Solved by the Invention) However, in the case of performing spot erase for erasing a part of the audio data recorded on the tape by the above-mentioned R-DAT or the like, if the erasing operation is executed once, the main signal However, even if it is desired to change the erasing position later, the previous main signal cannot be restored and therefore the erasing position cannot be changed.

In view of the above-mentioned problems, the present invention does not directly erase the main signal even when partially erasing a tape on which audio or the like called spot erase is recorded, writes erase information in the sub signal and executes the main erase operation. It is an object of the present invention to provide a digital signal reproducing device which can restore the main signal such as the original voice after that and can change the erasing position and the erasing interval any number of times.

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

(Operation) According to the present invention, with the above-described configuration, when performing spot erase for erasing a part of the audio data recorded on the tape, the timing signals of the mute start and the end are written by dubbing only in the sub signal area, During reproduction, the mute information is read from this sub signal area, and the main signal is muted accordingly. To correct the mute position and mute interval, it is possible to rewrite only the mute information in the sub signal area by post-recording.

(Example) An example of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of an R-DAT recording / reproducing circuit according to an embodiment of the present invention. In FIG. 1, reference numeral 1 is a recording medium, and a magnetic tape is used in this embodiment.
2 is a rotary cylinder to which a recording / reproducing head is attached, 3
Is a recording amplifier, 4 is a reproducing 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, and a is an audio signal input terminal. , B are audio signal output terminals, and c is an erase button.

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

The tape that has already been recorded is reproduced, the reproduction signal is obtained from the magnetic tape 1 by the magnetic head, and this is reproduced amplifier.
After being amplified and waveform-shaped by the equalizer 4, the signal processing circuit 5 performs demodulation, error correction, etc., and outputs a main signal and a sub signal. The main signal is converted into an audio signal by the D / A converter 7 and output to the audio signal output terminal b.
While observing the reproduced sound, when the operator recognizes that the position to be deleted is reached, the delete button is pressed. At this time, the reproduction from the tape is continued and the reproduced audio signal is continuously obtained at the audio signal output terminal b, but the system control microcomputer stores the time code of the pressed timing in the internal memory or the like as the erasing start point. When the erase button is further released, this timing is also stored as the erase end point and the reproduction is stopped. After that, while the sub signal is being reproduced, the tape is rewound a few frames before the start of erasing, and the post-recording of the sub signal is started. For example, as shown in FIG. 2, the mute information includes time codes of the erase start point and the end point, and erase start and end information as an erase start point pack and an erase end point pack, respectively. Is written in the sub signal area so that it is recorded only in a few frames before and after the start point, and the pack for the end point is recorded only in a few frames before and after the end point. Alternatively, both packs may be continuously recorded from several frames before the erasing start point to several frames after the erasing end point. When reproducing the tape on which the sub-signal of the mute information is recorded, the system control microcomputer 8 can obtain the mute start information from the sub-signal several frames before the position where the mute start is desired. The system control microcomputer 8 stores this information in an internal memory or the like,
Compare with the timecode played from the tape. When both match, a start instruction is given to the mute circuit. The mute circuit uses an AND gate such as 74HCO8 of a CMOS general-purpose logic IC. A digital audio signal is applied to one input and a mute signal is applied from the system control microcomputer 8 to the other input. If the mute signal is at the H level, a digital audio signal is output to the output of the AND gate, but if the mute signal is at the L level, the output of the AND gate is fixed at L and muted.

Also, 2 inputs 1 like CMOS general-purpose logic IC 74HC157
It is also possible to use an output selector to switch the digital audio signal to a digital signal prepared in advance in a memory or the like or a digital signal added from the outside by a mute start instruction. The end of mute can be realized by performing the same processing.

When changing the mute position, only the mute start point pack and the mute end point pack need be rewritten by post-recording.

As described above, according to the present embodiment, the mute start and end timing information is written by post-recording only to the sub-signal area, the mute information is read from the sub-signal area during reproduction, and the main signal is muted accordingly. By providing a circuit, it is possible to restore the original main signal such as the original sound even after performing the erasing operation even when spot erasing is performed to partially erase the tape on which the audio is recorded. It can be changed at any time.

(Effects of the Invention) According to the present invention, a main signal obtained by converting a signal such as voice into a digital signal and a subsidiary sub-signal accompanying the main signal are recorded in a recording medium, a recording / reproducing circuit, and a sub-signal reproduced from the recording medium. By providing a circuit to mute the main signal to be played back at the timing specified by, the main data such as the original audio data is erased even after the erasing operation is performed even during spot erase to partially erase the tape on which the audio data is recorded. Can be restored, and the erasing position and erasing interval can be changed any number of times, which has a great practical effect.

[Brief description of the drawings]

FIG. 1 is a block diagram of an R-DAT recording / reproducing circuit in an embodiment of the present invention, FIG. 2 is a diagram showing a position where mute information is recorded, and FIG. 3 is a track format diagram of R-DAT. FIG. 4 is an R-DAT track format diagram. 1 ... Magnetic tape, 2 ... Rotating cylinder, 3 ... Recording amplifier, 4 ... Playing 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: Erase button.

Claims (1)

(57) [Claims] 1. A circuit for recording / reproducing a main signal obtained by converting an analog signal such as music into a digital signal and a subsidiary sub-signal accompanying the main signal, and a sub-signal reproduced from the recording medium. At the timing
A digital signal recording / reproducing apparatus comprising a circuit for muting a main signal to be reproduced.