JPH0814975B2 - Digital signal recording / reproducing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention is applied to a recording medium such as a magnetic tape by interrupting the first digital data such as PCM audio data.
The present invention relates to a digital signal recording / reproducing device for recording second digital data such as PCM audio data.

(Summary of the Invention) The present invention also applies to a recording medium such as a magnetic tape by interrupting the first digital data such as PCM audio data.
In the digital signal recording / reproducing apparatus for recording the second digital data such as PCM audio data, the second
Recording medium together with the interrupt start signal and the interrupt end signal by obtaining the interrupt start signal and the interrupt end signal at the interrupt start point and the interrupt end point of the digital data, and interrupting the second digital data with the first digital data. The recorded digital signal is recorded at the same time, and the reproduced digital signal in which the second digital data is interrupted by the first digital data is delayed for a predetermined time at the time of reproduction, and based on the reproduced interrupt start signal and interrupt end signal. By reducing the delayed digital signal at the interrupt start point and interrupt end point of the second digital data, the delayed digital signal is arranged at a position preceding the recording / reproducing head and recorded on the recording medium at the time of recording the second digital data. The first digital data By using a simple head mechanism that does not require a special reproducing head, it is possible to prevent inconveniences such as a click sound being generated at the interrupt start point and the interrupt end point of the second digital data during reproduction. .

(Prior Art) A PCM audio signal is recorded by a rotary magnetic head on a track inclined with respect to the longitudinal direction of a magnetic tape, and in a device for reproducing from that track, the first PCM audio data recorded on the tape is interrupted. In addition, it is considered that new second PCM audio data is recorded on the tape to edit the audio. In this case, conventionally, a special reproducing head arranged at a position preceding the recording / reproducing head reproduces the first PCM audio data from the tape and reproduces the reproduced first PCM audio data.
Interrupt the second PCM voice data to the PCM voice data of
The PCM audio signal in which the second PCM audio data is interrupted by the first PCM audio data is recorded on the tape by the recording / reproducing head, and at this time, the first PCM is generated at the interrupt start point of the second PCM audio data. Playback is performed by gradually decreasing the audio data and gradually increasing the second PCM audio data, and gradually decreasing the second PCM audio data and gradually increasing the first PCM audio data at the interrupt end point of the second PCM audio data. At times, a click sound is not generated at the interrupt start point and the interrupt end point of the second PCM audio data.

That is, FIG. 4 shows a recording system of a conventional apparatus, which includes a recording / reproducing head 41 and a reproducing head 42 arranged at a position preceding the recording / reproducing head 41.
From the tape 43 by the playback head 42
The signal containing the PCM audio data is reproduced, and the reproduced signal is supplied to the reproduction processing circuit 44, and the first PCM audio data Da is obtained from the reproduction processing circuit 44, which is the multiplication circuit 45.
Is supplied to. Also, from the terminal 46 to the multiplication circuit 47, the second PC
M audio data Db is supplied. Then, the information signal Ic of the start and end of interruption is supplied from the terminal 48 to the coefficient setting circuit 49, coefficient data Ka and Kb described later are obtained from the coefficient setting circuit 49, and the coefficient data Ka is supplied to the multiplication circuit 45. Is multiplied by the first PCM audio data Da, the coefficient data Kb is supplied to the multiplication circuit 47 and left unmultiplied by the second PCM audio data Db, and the first PCM audio data Dak obtained from the multiplication circuit 45.
The second PCM audio data Dbk obtained from the multiplication circuit 47 is supplied to the addition circuit 51 and added.

Coefficient data Ka and Kb obtained from the coefficient setting circuit 49
In the PCM audio data Dc obtained from the adder circuit 51, as shown in FIG. 5, during the interrupt start period Ti of the second PCM audio data Db for a predetermined time, the first PCM obtained from the multiplication circuit 45 The audio data Dak gradually decreases, the second PCM audio data Dbk obtained from the multiplication circuit 47 gradually increases, and the second PCM audio data Db is obtained from the multiplication circuit 47 in the interrupt end period To of the predetermined time. 2's
The PCM audio data Dbk is gradually decreased, and the first PCM audio data Dak obtained from the multiplication circuit 45 is gradually increased. Then, the PCM audio data Dc obtained from the adder circuit 51 is supplied to the encoder 52, to which a synchronizing signal and an error correction code are added, and the PCM obtained from the encoder 52.
The audio signal is supplied to the recording / reproducing head 41 through the recording / amplifying circuit 53 and recorded on the tape 43 by the head 41.

(Problems to be Solved by the Invention) However, the conventional apparatus reproduces the first digital data recorded on the recording medium when the second digital data is recorded at a position preceding the recording / reproducing head. It requires a special reproducing head to be used, which makes the head mechanism complicated and expensive.

In view of such a point, the present invention requires a special reproducing head which is arranged at a position preceding the recording / reproducing head and reproduces the first digital data recorded on the recording medium at the time of recording the second digital data. The simple head mechanism does not cause any inconvenience such as the generation of a click sound at the interrupt start point and the interrupt end point of the second digital data during reproduction.

(Means for Solving Problems) In the present invention, an interrupt start signal is generated at the interrupt start point and the interrupt end point of the second digital data which is recorded in the recording medium by interrupting the recording system with the first digital data. And means for generating an interrupt end signal, and means for interrupting the second digital data into the first digital data and recording it on a recording medium together with the interrupt start signal and the interrupt end signal. Means for reproducing a digital signal in which the second digital data is interrupted from the recording medium by the second digital data and the interrupt start signal and interrupt end signal, and delaying the reproduced digital signal for a predetermined time. Means and the reproduced interrupt start signal and interrupt end signal. Means for reducing the delayed digital signal at the interrupt start point and interrupt end point of the second digital data based on the end signal.

(Operation) According to the digital data signal recording / reproducing apparatus of the present invention configured as described above, at the time of recording, at the interrupt start point and interrupt end point of the second digital data, the first digital data or the second digital data is generated. In order to gradually decrease or increase the digital data, it is not necessary to reproduce the first digital data recorded on the recording medium by the special reproducing head arranged at the position preceding the recording / reproducing head.

(Embodiment) FIG. 1 shows an example of a digital signal recording / reproducing apparatus according to the present invention, in which a PCM audio signal is recorded on a track inclined with respect to a longitudinal direction of a magnetic tape by a rotating magnetic head and reproduced from the track. This is the case.

A signal including the first PCM audio data is recorded on the magnetic tape 11 in a track inclined with respect to the longitudinal direction.

At the time of recording, the second PCM audio data Di is supplied from the terminal 21 to the interrupt circuit 22, and the interrupt signal Sc as shown in the upper part of FIG. , Interrupt circuit 22 to second
As shown in the middle part of the figure, the second PCM audio data Db is obtained during the high level period of the interrupt signal Sc. Further, the interrupt signal Sc is supplied from the terminal 23 to the signal generation circuit 24, and the interrupt start signal Fi and the interrupt start signal Fi are generated immediately after the rising edge and immediately before the falling edge of the interrupt signal Sc from the signal generating circuit 24 as shown in the lower part of FIG. Interrupt end signal Fo
Is obtained. The interrupt start signal Fi and the interrupt end signal Fo are different from each other in that the pulse code of the sample unit or block unit of the PCM audio data is different from the second PC.
The M audio data Db have the same contents in a plurality of sample periods or a plurality of block periods.

The second PCM audio data Db obtained from the interrupt circuit 22
And the interrupt start signal Fi and the interrupt end signal Fo obtained from the signal generation circuit 24 are supplied to the encoder 25, and the encoder 25 synthesizes and synchronizes the second PCM audio data Db with the interrupt start signal Fi and the interrupt end signal Fo. Encoder with added signal and error correction code
From 25, a PCM audio signal including the second PCM audio data Db, the interrupt start signal Fi and the interrupt end signal Fo is obtained in the form of serial data. Then, the PCM audio signal obtained from the encoder 25 is supplied to the rotary magnetic head through the recording amplification circuit 26 and the recording side terminal R of the recording / reproducing changeover switch 12.
Is supplied to the magnetic tape 11 by the head 13
The PCM audio data Db is recorded in a state of including the interrupt start signal Fi and the interrupt end signal Fo and interrupting the first PCM audio data.

At the time of reproduction, a signal including the PCM audio signal in a state where the second PCM audio data Db including the interrupt start signal Fi and the interrupt end signal Fo is interrupted by the rotary magnetic head 13 into the first PCM audio data is generated. The reproduced signal is reproduced, and the reproduced signal is recorded on the reproducing side terminal p of the recording / reproducing switch 12.
Is supplied to the reproduction processing circuit 32 through the reproduction amplification circuit 31, and the second PCM audio data Db is interrupted from the reproduction processing circuit 32 into the first PCM audio data including the interrupt start signal Fi and the interrupt end signal Fo. PCM audio signal is obtained in the form of parallel data, and this is supplied to the decoder 33. From the decoder 33, the first PCM audio data Da is converted into the second PCM audio data Da as shown in the first and third stages of FIG. The PCM audio signal Dc interrupted by the PCM audio data Db, the interrupt start signal Fi and the interrupt end signal Fo are obtained separately.
The PCM audio signal Dc obtained from the decoder 33 is the delay memory 3
4 is supplied to and written in, and the written PCM audio signal is read from the delay memory 34 with a delay of a predetermined time,
As shown in the second stage of FIG. 3, a PCM voice signal Dd obtained by delaying the PCM voice signal Dc obtained from the decoder 33 for a predetermined time is obtained from the delay memory 34, and this is supplied to the multiplication circuit 35. The interrupt start signal Fi and the interrupt end signal Fo obtained from the decoder 33 are supplied to the coefficient setting circuit 36, and coefficient data Kd described later is obtained from the coefficient setting circuit 36,
This is supplied to the multiplication circuit 35 and delayed PCM audio signal Dd
Is multiplied by.

The coefficient data Kd obtained from the coefficient setting circuit 36 is the second PCM audio data Db in the delayed PCM audio signal Dd in the PCM audio signal Dk obtained from the multiplication circuit 35, as shown in the fourth row of FIG. In the period of the predetermined time immediately before the interruption start point of the first PCM audio data Da
At the predetermined time period immediately after the interrupt start point of the second PCM audio data Db in the delayed PCM audio signal Dd, the second PCM audio is gradually reduced to zero at the interrupt start point of the CM audio data Db. The data Db is gradually increased so as to become zero at the interrupt start point, and the second PCM audio data is output in the predetermined time period immediately before the interrupt end point of the second PCM audio data Db in the delayed PCM audio signal Dd. Db is gradually reduced to zero at the interrupt end point, and the first PCM audio data Da is output during a predetermined time period immediately after the interrupt end point of the second PCM audio data Db in the delayed PCM audio signal Dd. Is the second PCM audio data Db
The value is gradually increased so that it becomes zero at the interrupt end point. And the PC obtained from the multiplication circuit 35
The M audio signal Dk is supplied to the D / A converter 37, converted into an analog audio signal, and reproduced at the output terminal 38.
You get Sa.

In the above device, during reproduction, the PCM audio signal Dk obtained from the multiplication circuit 35 is the first PCM audio data Da and the second PCM audio data at the interrupt start point and interrupt end point of the second PCM audio data Db. Since Db is set to zero, no click sound is generated at the interrupt start point and interrupt end point of the second PCM audio data Db.

(Effects of the Invention) As described above, according to the present invention, the second digital data such as PCM voice data is also recorded on the recording medium such as the magnetic tape by interrupting the first digital data such as PCM voice data. In the digital signal recording / reproducing apparatus, the second signal is arranged at a position preceding the recording / reproducing head.
The second head is reproduced at the time of reproduction by a simple head mechanism that does not require a special reproduction head for reproducing the first digital data recorded on the recording medium at the time of recording the first digital data.
It is possible to prevent inconvenience such as generation of a click sound at the interrupt start point and the interrupt end point of the digital data.

[Brief description of drawings]

FIG. 1 is a block diagram showing an example of a digital signal recording / reproducing apparatus according to the present invention, FIGS. 2 and 3 are diagrams showing modes of signals obtained in respective parts of the recording system and reproducing system, and FIG. FIG. 5 is a block diagram showing a recording system of an example of a conventional digital signal recording / reproducing apparatus, and FIG.
It is a figure which shows the aspect of M audio | voice data. In the figure, 11 is a magnetic tape, 13 is a rotary magnetic head, 22 is an interrupt circuit, 24 is a signal generating circuit, 34 is a delay memory, 35 is a multiplying circuit, and 36 is a coefficient setting circuit.

Claims (1)

[Claims] 1. Means for generating an interrupt start signal and an interrupt end signal at an interrupt start point and an interrupt end point of second digital data which is interrupted by the first digital data and recorded on a recording medium. A recording system having means for interrupting digital data into the first digital data and recording the interrupt start signal and the interrupt end signal on a recording medium; and a second digital data from the recording medium to the first digital data. Based on the means for reproducing the digital signal in the state where the data is interrupted, the interrupt start signal and the interrupt end signal, the means for delaying the reproduced digital signal for a predetermined time, and the reproduced interrupt start signal and interrupt end signal. The delayed digital signal to And a reproduction system having means for reducing the interruption start point and the interruption end point of the digital data of 2.