JPS6369084A - Digital signal recording and reproducing device - Google Patents

Abstract

PURPOSE:To prevent the generation of a click sound by recording an interruption data in a recording medium recorded digital data together with an interruption starting/completion signal, and decreasing a digital signal at an interruption starting/completion point at the time of reproducing. CONSTITUTION:When interruption PCM sound data Di and an interrupting signal Sc are supplied, data Db and an interruption starting signal Fi/completing signal Fo are obtained, and interrupted and recorded through an encoder 25 and a recording reproducing changing-over switch 12 to a tape 11. At the time of reproducing, sound data Dc and signals Fi and Fo outputted from an encoder 33 are outputted as a PCM sound signal Dk to decrease gradually or increase gradually so that they go to respectively zero through a memory 34 for delay, a coefficient setting circuit 36 and a multiplier 35 in an interruption starting completing point. Consequently, without using a special reproducing head, the generation of the click sound can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention provides the ability to interrupt first digital data, such as PCM audio data, to record the same data on a recording medium such as a magnetic tape.
The present invention relates to a digital signal recording and reproducing device that records second digital data such as PCM audio data.

(Summary of the Invention) The present invention provides a first digital data such as PCM audio data and the like to be recorded on a recording medium such as a magnetic tape.
In a digital signal recording and reproducing device that records second digital data such as PCM audio data, when recording, an interrupt start signal and an interrupt end signal are obtained at the interrupt start point and interrupt end point of the second digital data, and the The digital data of No. 2 is inserted into the first digital data and recorded on the recording medium together with the above-mentioned interrupt start signal and interrupt end signal. By delaying the reproduced digital signal for a predetermined time and reducing the delayed digital signal at the interrupt start point and interrupt end point of the second digital data based on the reproduced interrupt start signal and interrupt end signal. , a simple head mechanism that does not require a special playback head that is placed in a position preceding the recording/playback head and plays back the first digital data recorded on the recording medium when the second digital data is recorded. This prevents inconveniences such as clicking sounds from occurring at the interrupt start point and interrupt end point of the second digital data.

(Prior Art) In a device that records a PCM audio signal using a rotating magnetic head on a track that is inclined with respect to the longitudinal direction of a magnetic tape and plays it back from that track, it is possible to interrupt the first PCM audio data recorded on the tape. A new second P
It has been considered to record commercial audio data on tape and edit the audio. In this case, conventionally, the first PCM audio data is played back from the tape by a special playback head placed in a position preceding the recording/playback head, and the second PCM audio is added to the played first PCM audio data. This first PCM audio data is interrupted by a second PCM data.
The PCM audio signal interrupted by the CM audio data is recorded on tape by the recording/playback head, and at that time, the second PCM audio signal is
The first PCM at the interrupt start point of CM audio data.
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,
Click sounds are prevented from being generated at the interrupt start point and interrupt end point of the second PCM audio data during reproduction.

That is, FIG. 4 shows a recording system of a conventional apparatus, which includes a recording/reproducing head 41 and a reproducing head 4 disposed in a position preceding the recording/reproducing head 41.
2, a signal including the first PCM audio data is reproduced from the tape 43 by the reproduction head 42, the reproduced signal is supplied to the reproduction processing circuit 44, and the signal containing the first PCM audio data is reproduced from the reproduction processing circuit 44. PCM audio data Da is obtained,
This is supplied to a multiplication circuit 45. Further, the second PCM audio data Db is supplied from the terminal 46 to the multiplication circuit 47 . Then, the information signal Ic indicating the start and end of the interrupt is supplied from the terminal 48 to the coefficient setting circuit 49, coefficient data Ka and Kb, which will be described later, are obtained from the coefficient setting circuit 49, and the coefficient data Ka is supplied to the multiplication circuit 45. The coefficient data Kb is supplied to a multiplication circuit 47 and multiplied by the second PCM audio data Db, and the first PCM audio data Dak obtained from the multiplication circuit 45 and the multiplication circuit are multiplied by the first PCM audio data Da. The second PCM obtained from 47
The audio data Dbk is supplied to the adding circuit 51 and added.

Coefficient data Ka and K obtained from the coefficient setting circuit 49
b is PCM audio data Dc obtained from the addition circuit 51
As shown in FIG. 5, in the predetermined interrupt start period Ti of the second PCM audio data Db,
The first PCM audio data Da obtained from the multiplication circuit 45
As k gradually decreases, the second
The PCM audio data Dbk gradually increases, and in the predetermined interrupt end period To of the second PCM audio data Db, the second PCM audio data Dbk obtained from the multiplication circuit 47 gradually decreases, and the second PCM audio data Dbk obtained from the multiplication circuit 45 gradually decreases. This is so that the first PCM audio data Dak that is displayed gradually increases. Then, the PCM audio data Dc obtained from the adder circuit 51 is supplied to the encoder 52 to which a synchronization signal, an error correction code, etc. are added, and the PCM audio signal obtained from the encoder 52 is supplied to the recording/reproducing head 41 via the recording amplifier circuit 53. tape 43 by the head 41.
recorded in - (Problems to be Solved by the Invention) However, the conventional device is arranged at a position preceding the recording/reproducing head and records the first digital data recorded on the recording medium when recording the second digital data. A special reproducing head is required for reproduction, and the head mechanism is disadvantageously complicated and expensive.

In view of this, the present invention requires a special playback head that is placed in a position preceding the recording/playback head and plays back the first digital data recorded on the recording medium when the second digital data is recorded. By using a simple head mechanism that does not require any noise, inconveniences such as click sounds occurring at the interrupt start point and interrupt end point of the second digital data during reproduction are avoided.

(Means for Solving the Problems) In the present invention, the recording system generates an interrupt start signal at the interrupt start point and the interrupt end point of the second digital data to be recorded on the recording medium by interrupting the first digital data. and means for generating an interrupt end signal; and means for causing the second digital data to interrupt the first digital data and record 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 first digital data is interrupted by the second digital data, the interrupt start signal and the interrupt end signal from a recording medium, and delaying the reproduced digital signal for a predetermined period of time. and means for reducing the delayed digital signal at the interrupt start point and interrupt end point of the second digital data based on the reproduced interrupt start signal and interrupt end signal.

(Function) According to the digital signal recording and reproducing apparatus according to the present invention configured as described above, during recording, the first digital data to the second digital data are recorded at the interrupt start point and the interrupt end point of the second digital data. There is no need to reproduce the first digital data recorded on the recording medium by means of a special reproduction head positioned in advance of the recording/reproduction head in order to gradually decrease or increase the data.

(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 the longitudinal direction of a magnetic tape by a rotating magnetic head.
This is the case when playing from that trunk.

A signal containing first PCM audio data is recorded on the magnetic tape 11 in tracks inclined with respect to its longitudinal direction.

During recording, the second PCM is sent from the terminal 21 to the interrupt circuit 22.
When the audio data Di is supplied, an interrupt signal SC as shown in the upper part of the second figure which determines the interrupt period is supplied from the terminal 23 to the interrupt circuit 22, and from the interrupt circuit 22 to the middle part of Figure 2. Interrupt signal S as shown
During the cO high level period, the second PCM audio data D
b is obtained. Further, the interrupt signal Sc is supplied from the terminal 23 to the signal generation circuit 24, and the signal generation circuit 24 generates the interrupt start signal Fi and An interrupt end signal FO is obtained. The interrupt start signal Fi and the interrupt end signal Fo are such that the pulse codes in units of samples or blocks of the PCM audio data, which have different contents, are the same in the multiple sample periods or multiple block periods of the second PCM audio data Db, respectively. It exists in

The second PCM audio data Db obtained from the interrupt circuit 22 and the interrupt start signal Fi and interrupt end signal FO obtained from the signal generation circuit 24 are supplied to the encoder 25, where the second PCM audio data Db and the interrupt start signal are supplied. The signal Fi and the interrupt end signal FO are synthesized, a synchronization signal, an error correction code, etc. are added, and the PCM audio signal including the second PCM audio data Db, the interrupt start signal Fi, and the interrupt end signal FO is serially output from the encoder 25. Obtained in the form of data. Then, PCM' obtained from the encoder 25
The audio signal is supplied to the rotary magnetic head 13 through the recording amplification circuit 26 and the recording side terminal R of the recording/reproduction changeover switch 12, and the head 13 transfers the second PCM audio data Db to the magnetic tape 11 as an interrupt start signal Fi and an interrupt signal. It is recorded in a state in which it includes the end signal FO and interrupts the first PCM audio data.

A signal containing a PCM audio signal in which the second PCM audio data Db is inserted from the magnetic tape 11 by the rotating magnetic helad 13 into the first PCM audio data including the interrupt start signal Fi and the interrupt end signal Fo during playback. is reproduced, and the reproduced signal is transferred to the recording/reproduction selector switch 1.
It is supplied to the reproduction processing circuit 32 through the reproduction side terminal P of the second
A PCM audio signal in which the first PCM audio data Db includes the interrupt start signal Fi and the interrupt end signal FO and interrupts the first PCM audio data is obtained in the form of parallel data, and this is supplied to the decoder 33, and the decoder 33 to 3, as shown in the first and third stages of FIG. A termination signal FO is obtained separately. The PCM audio signal Dc obtained from the decoder 33 is supplied to and written into the delay memory 34, and the written PCM audio signal is read out from the delay memory 34 after a predetermined time delay, and is then read out from the delay memory 34 into the third delay memory 34.
As shown in the second stage of the figure, the PC obtained from the decoder 33
A PCM audio signal Dd delayed by a predetermined time with respect to the M audio signal Dc is obtained, 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,
Coefficient data Kd, which will be described later, is obtained from the coefficient setting circuit 36,
This is supplied to the multiplication circuit 35 and multiplied by the delayed PCM audio signal Dd.

The coefficient data Kd obtained from the coefficient setting circuit 36 is the delayed PCM audio signal D in the PCM audio signal Dk obtained from the multiplication circuit 35, as shown in the fourth stage of FIG.
During a predetermined time period immediately before the interrupt start point of the second PCM audio data Db at time d, the first PCM audio data Da gradually decreases to zero at the interrupt start point of the second PCM audio data Db. , delayed PCM
In the predetermined time period immediately after the interrupt start point of the second PCM audio data Db in the audio signal Dd, the second
The PCM audio data Db gradually increases to zero at the interrupt start point, and during a predetermined time period immediately before the interrupt end point of the second PCM audio data Db in the delayed PCM audio signal Dd, the second PCM audio data Db increases gradually to zero at the interrupt start point. The PCM audio data Db gradually decreases to zero at the interrupt end point, and the second P in the delayed PCM audio signal Dd
During a predetermined period of time immediately after the interrupt end point of the CM audio data Db, the first PCM audio data Da is
The value is gradually increased to zero at the interrupt end point of the PCM audio data Db. Then, the PCM audio signal Dk obtained from the multiplication circuit 35 is supplied to the D/A converter 37 and converted into an analog audio signal, and a reproduced analog audio signal Sa is obtained at the output terminal 38.

In the above-mentioned apparatus, during reproduction, the PCM audio signal Dk obtained from the multiplication circuit 35 is the second PCM audio data Db.
The first PCM audio data Da and the second PCM audio data D at the interrupt start point and interrupt end point of
Since b 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 same <second digital data such as PCM audio data is recorded on a recording medium such as a magnetic tape by interrupting the first digital data such as PCM audio data. In a digital signal recording and reproducing apparatus for recording, a special reproducing head is required which is placed in a position preceding the recording and reproducing head and reproduces the first digital data recorded on the recording medium when the second digital data is recorded. By employing a simple head mechanism that does not include the above, it is possible to prevent inconveniences such as the occurrence of click sounds at the interrupt start point and interrupt end point of the second digital data during reproduction.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an example of a digital signal recording and reproducing apparatus according to the present invention, FIGS. 2 and 3 are diagrams showing the form of signals obtained in each part 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 device.
FIG. 3 is a diagram showing an aspect of CM audio data. In the figure, 11 is a magnetic tape, 13 is a rotating magnetic head, 22
24 is an interrupt circuit, 24 is a signal generation circuit, 34 is a delay memory, 35 is a multiplication circuit, and 36 is a coefficient setting circuit.

Claims (1)

[Scope of Claims] 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 to be recorded on a recording medium by interrupting the first digital data; a recording system having means for inserting the 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 the digital signal in which digital data is interrupted, the interrupt start signal and the interrupt end signal; means for delaying the regenerated digital signal for a predetermined time; and a reproducing system having means for reducing the delayed digital signal at the interrupt start point and the interrupt end point of the second digital data.