JPS62114106A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To attain the recording/reproduction of data information synchronously with >=2 tracks mutually by recording and reproducing a code relating to the track combination system recording/reproducing data information together with the data information. CONSTITUTION:In recording data information on tracks 1, 2, an ID code representing the 2S direction and the combination of the tracks 1, 2 is outputted to a changeover circuit 20 from an ID code input circuit 17, the 2-channel data information is recorded to the tracks 1, 2 and the ID code is recorded. At reproduction, the ID code is read by an ID code read circuit 18 of the reproducing system and outputted to the circuit 20. The circuit 20 switches the switch 10 so that the output signal when the heads 8, 9 are placed on the track 1 is inputted to a time base expanding demodulation circuit 12 of the one reproducing system and the output signal when placed at the track 2 is inputted to the other reproducing system circuit 12 and then each 2-channel information is reproduced from the tracks 1, 2.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic recording and reproducing apparatus typified by an 8 mm video tape recorder.

[Summary of the invention]

The present invention provides a magnetic recording and reproducing apparatus that divides an inclined track formed by a rotary head at an angle with respect to the running direction of a magnetic tape into a plurality of tracks, and records and reproduces predetermined data information on each track. When tracing a magnetic tape once, data information is recorded and reproduced on two or more tracks, and a code related to the combination of tracks for recording and reproducing data information is also recorded and reproduced together with the data information, thereby creating a so-called multi-track 8. Enables information on four or more channels to be recorded and played back in synchronization with each other in millimeter video tape recorders, etc., and allows the magnetic tape to be played back even in devices that can only record and play back two channels. This is what I did.

[Prior art] There are 1 8mm video tape recorders that have already been commercialized.
Not only is it smaller and lighter than a 2-inch video tape recorder, but it can also record not only video information, but also
It has recently attracted particular attention because it can also record and reproduce PCM audio information.

When PCM audio information is recorded and played back by an 8mm video tape recorder, an inclined track corresponding to a winding angle of approximately 221 degrees is formed by a rotating head at an angle with respect to the running direction of the magnetic tape, as shown in Fig. 7. Approximately 3 as shown
It is divided into six tracks (multitrack) corresponding to a winding angle of 6 degrees. Tracks 1 to 6 are further divided into areas a to d.
In the case of a 525 line, 60 field system represented by the NTSC system, and in the case of a 625 line, 50 field system represented by the PAL system,
Information is recorded as shown in FIG. In other words, for example, in the case of the NTSC system, the clock run-in signal is applied to area a corresponding to the minimum winding angle of 2.06 degrees to the maximum 5.0 degrees, and the clock run-in signal is applied to the area A corresponding to the winding angle of 26.32 degrees. The PCM audio information data of the left and right channels (2 channels) are recorded respectively, and the area C corresponding to the winding angle of 2.06 degrees is the after-recording margin area, and the winding angle is 2.62 degrees. The area d corresponding to the area d is used as a track guard section.

[Problem that the invention seeks to solve]

In this way, a conventional multi-track 8mm video tape recorder can independently record and reproduce two channels of data information on each of tracks 1 to 6. It has been difficult to record and reproduce mutually synchronized data information.

[Means for solving problems]

FIG. 1 is a block diagram when the magnetic recording and reproducing apparatus of the present invention is applied to an 8 mm video tape recorder. In the figure, 1 is a noise reduction circuit that compresses and outputs left and right channel (stereo) signals, and 2 is a noise reduction circuit that compresses and outputs left and right channel (stereo) signals. This is an A/D conversion circuit that converts the output of the noise reduction circuit 1 from an analog signal to a digital signal. A/D conversion circuit 2
The 10-bit digital signal outputted by the 10-8 conversion circuit is converted into an 8-bit digital signal according to a predetermined format, and is input to the error detection and correction code generation circuit 4. The error detection and correction code generation circuit 4 adds a code for detecting and correcting errors to the data information from the 1o-8 conversion circuit 3 and the ID (Identification) code input from the ID code input circuit 17, and outputs the code to the time axis compression modulation circuit 5. Output to. The output of the time axis compression modulation circuit 5 is
1 to 1 through switches 6 and 7 which are switched by head switching pulses output from the switching circuit 20.
It is fed alternately to rotating heads 8.9 spaced 80 degrees apart.

The output of the rotary head 8.9 is input to a time-base expansion demodulation circuit 12 via a switch 10, and its output is supplied to an error detection and correction circuit 13. The error detection and correction circuit 13 separates the data information and the ID code, outputs the ID code to the ID code reading circuit 18, and also outputs the data information once stored in a memory 19 such as a RAM to the 8-10 conversion circuit 14.
Output to. D/A conversion circuit 15 is 8-10 conversion circuit 1
4 is converted from a digital signal to an analog signal and output to the noise reduction circuit 16.

[Effect]

The effect will now be explained. The two-channel stereo (L, R) signal is compressed by the noise reduction circuit 1, and then converted from the analog signal by the A/D conversion circuit 2.
It is converted to a 0-bit digital signal. The digital signal output from the A/D conversion circuit 2 is converted from 10 bits to 8 bits by a 10-8 conversion circuit 3 according to a predetermined conversion table. The data information converted into 8 bits is added to the ID code output by the ID code input circuit 17 by the error detection and correction code generation circuit 4. The ID code is composed of five words ID-1 to ID-5, and each ID word is composed of 8-bit binary signals BO to B7.

The error detection and correction code generation circuit 4 adds a code for error detection and correction to the data information and ID code, and supplies the data information and the ID code to the time axis compression modulation circuit 5. The time axis compression modulation circuit 5 compresses the time axis of the input signal, performs pie-phase modulation, and outputs the signal. The switches 6 and 7 are switched by head switching pulses output from the switching circuit 20 at predetermined timings.9 For example, when recording information on track 1, the rotary head 8 or 9 alternately changes the time axis at the timing when it is positioned on track 1. It is connected to the compression modulation circuit 5. Therefore, two channels of (stereo) PCM audio information are recorded on track 1.

Similarly, during reproduction, the switching circuit 20 is activated at the timing when the rotary head 8 or 9 is located at the track to be reproduced.
outputs a head switching pulse to switch 10,
The rotary heads 8 or 9 are alternately connected to the time axis expansion demodulation circuit 12. Therefore, the reproduced signal from a predetermined track is input to the time axis expansion demodulation circuit 12, and the time axis compression modulation circuit 5
The time axis is expanded in a complementary manner to the time axis compression in , and is further demodulated and output. The error detection and correction circuit 13 once stores the data information and the ID code in the memory 19, detects and corrects errors therein, and then separates and outputs the two. ID
The code is supplied to the ID code reading circuit 18 and read. Further, the data information is restored from 8 bits to the original 10 bits by the 8-10 conversion circuit 14 according to a predetermined conversion table. The digital signal converted to 10 bits is D/
The A conversion circuit 15 converts the signal into an analog signal, and the noise reduction circuit 16 performs expansion complementary to the compression in the noise reduction circuit 1. The output of the noise reduction circuit 16 is outputted to a speaker via an amplifier, for example (the chair is not shown).

The above is an explanation for recording two channels of audio data independently on tracks 1 to 6. Next, the rotary head 8 or 9 records the magnetic tape once (from the beginning to the end of one inclined track). ) When tracing, the operation when recording and reproducing signals in synchronization with two or more tracks among tracks 1 to 6 will be explained. Recording and reproduction of such signals is performed as shown in FIG.

In other words, when two 2-channel signals are synchronously recorded and reproduced on two tracks (hereinafter referred to as 28 system), the number of recording and reproduction systems is two, and track 1 and track 2, track 3 and track 4, Track 5 and track 6 are each set as one set (FIG. 6(a)). For example, when recording data information on tracks 1 and 2, the ID code input circuit 17 sends a code signal indicating the 28 system to the switching circuit 20, or a code signal representing the 28 system and one set of tracks 1 and 2. A code signal indicating that this is the case is output. As a result, the switching circuit 20 switches the switch 6.7 while the rotary head 8 or 9 traces the inclined track once, and when the rotary head 8 or 9 is located on track 1, the time axis compression modulation of one recording system is performed. The output signal from the circuit 5 is input to the rotary head 8 or 9, and when the rotary head 8 or 9 is located on track 2, the output signal from the time axis compression modulation circuit 5 of the other recording system is input to the rotary head 8 or 9. Let them input. Therefore, two channels of data information are recorded on track 1 and track 2, respectively.

Also, at this time, information indicating that the 28 system is used, or information indicating that recording has been performed in the 28 system with track 1 and track 2 as one set, is recorded on tracks 1 and 2 as an ID code. At the time of playback, this ID code is read by the I'D code reading circuit 1 of at least one playback system.
8 and outputs the detection signal to the switching circuit 20. Therefore, the switching circuit 20
When the rotary head 8 or 9 is located on track 1, the output signals from them are sent to the time axis expansion demodulation circuit 12 of one reproduction system, and when the rotary head 8 or 9 is located on track 2, the output signals from them are sent to the other reproduction system. The switch 10 is changed so as to input each signal to the time axis expansion demodulation circuit 12 of the system. Therefore, information of two channels each (four channels in total) is reproduced from track 1 and track 2.

In the case of the No. 28 system, the running direction of the magnetic tape is all in the forward direction (to the left in the figure), and running in the reverse direction is prohibited. Theoretically, running in the opposite direction is possible, but according to the multi-track 8mm video tape recorder standard (mode 7), running in the opposite direction is only allowed on tracks 2.4.
．． 6, and trucks 1, 3, and 5 are prohibited from traveling in the opposite direction. Therefore, in order to ensure compatibility with the case where data information is recorded and reproduced independently on each track 1 to 6, in the case of the 28 system, it is preferable to allow only recording and reproduction in the forward direction.

Next, when data information is recorded and reproduced synchronously on three tracks (hereinafter referred to as 38 method), tracks 1, 3, .
5 and tracks 2, 4, and 6 are each made into one set (6th
Figure (b)). As in the previous case, from a compatibility point of view,
The set of tracks 1.3.5 allows recording and reproduction only in the forward direction, and the set of tracks 2.4.6 allows recording and reproduction in the forward and reverse directions.

Synchronizes data information recording and playback on 6 tracks (
(hereinafter referred to as 68 method), tracks 1 to 6 are 1
(Fig. 6(C)).

In this case, as in the case described above, only recording and reproduction in the forward direction is allowed from the viewpoint of compatibility.

-11= Even in the case of the 3S and 68 systems, the ID code is recorded and reproduced together with data information, as in the case of the 28 system. Further, in this case, it is necessary to increase the number of recording/reproducing systems to three or six, or to time-divide a smaller number of systems to serve the same purpose.

Next, the operation when performing after-recording in any one of the 28, 3S, and 68 systems will be explained. For example, in the 28 system consisting of track 1 and track 2, audio data information (for example, an accompaniment song) recorded in advance on track 1 is played back, and while listening to the audio data information (accompaniment song), other players are synchronized with the audio data information (accompaniment song). Record the audio data information (e.g. song) on track 2 (after-recording)
In this case, the switching circuit 20 selects the rotary head 8 or 9 in response to the signal from the ID code input circuit 17 if it is on the track 1.
Connect to the playback system when the track 2 is at the position corresponding to
Connect to the recording system when it is at the position corresponding to . However, there is a slight delay time before the digital audio signal recorded on track 1 is output as an analog audio signal. This delay time is not necessarily basically the same between different video tape recorders.

Therefore, information regarding this delay time is also recorded as an ID code on at least track 2 (or further on track 1). During playback, this ID code is read by the ID code reading circuit 18. The ID code reading circuit 18 outputs a control signal to the memory 19 of the error detection and correction circuit 13 of the reproduction system of track 1, and corresponds to the delay time when reading the timing at which the reproduction data information from track 1 is output from the memory 19. delay by the amount of time required. Alternatively, the timing at which the reproduced data information of track 2 is output from the memory 19 is advanced by a time corresponding to the read delay time. Therefore, it becomes possible to synchronize the reproduction signals from both tracks and reproduce them at the same time. Of course, since the rotary head 8 or 9 reproduces track 2 after reproducing track 1, a delay occurs during this time, but this delay time is equal to the time it takes for the rotary head 8.9 to trace one 1-rack (of 1 field). It is constant because it is equal to 115) of time. Therefore, compensation for this delay time is 2S, 3S
, 68 can be specified, so it is possible to do this automatically when the ID code related to the track combination method is read.

In the case of the 3S or 68 system, the delay time is either the delay time for the data information recorded on the lowest numbered track, or the delay time for the data information recorded on the immediately preceding track in the combination thereof. be able to.

Next, an example will be described in which information regarding the track combination method and information regarding the delay time are recorded as an ID code. Word ID-0 of the ID code is the mode (
This number is specified in the 8mm video tape recorder standard as a display number. Also word ID-5
is defined in the multi-track 8mm video tape recorder standard (Mode 7) to represent various control words (e.g. dubbing protection, distinction between audio information and other information, distinction between monaural, stereo, bilingual, etc.). It is being Since the present invention is also a type of multi-track 8 mm video tape recorder, it is preferable for compatibility to record and reproduce the ID word defined in the standard as mode 7 as is. Therefore, for example, the words ID-2 and ID-3 contain information regarding the delay time, the word ID-1 contains information to distinguish the method, and the word ID-2 and ID-3 contain information indicating that the delay time is specified. Make sure to record it.

For example, as shown in FIG. 2, bit B of word ID-1
Of the 4 bits from O to B3, when BO is 1, it is 6
8 system, 38 system when B1 is 1, 28 system when B2 is 1, IS system (conventional multi-track system) when B3 is 1, and ID-2 and ID-3 have delay time. As information indicating that there is a designation, bit B4 is set to 1,
Bit B5. B6. B7 can each be set to 0.

Then, as shown in FIG. 3, bit B of word ID-2
The 4 bits 4 to B7 represent the 100's of the delay time, the 4 bits B4 to B7 of word ID-3 represent the 10's of the delay time, and the 4 bits BO to B3 of word ID-3 represent the 10's of the delay time. Each digit of the delay time can be expressed and recorded as a decimal number.

When expressing a decimal number digitally, for example, the fifth
As shown in the figure, bits B3 (B7) to BO (B4)
When the 4 bits consisting of are 0110, it is 9 in decimal
1111 can be made to correspond to the decimal number O by incrementing it by 1. Since bits BO to B3 of word ID-2 are empty, use them,
For example, bits BO and B1 can specify a channel for which the delay time is targeted. In other words, when the delay time targets both left and right channels, bit BO,
Bl can be set to OO, 10 for the left channel, and 01 for the right channel.

If the above regulations are set to, for example, mode 8, information is recorded using the 38 method, and the delay time of both the left and right channels is 152 m5, words ID-0 to ID-3 are expressed as shown in FIG.

In this way, the IS system recorded and reproduced only 2 channels of information, but the 28 system synchronized information on 4 channels, the 38 system 6 channels, and the 68 system 12 channels of information. This makes it possible to record and play back. Moreover, even in a conventional (IS system) device that has only one recording/playback system, it is possible to play back any one track (two channels) of a magnetic tape recorded in each of the 2S, BS, or 6S systems. .

When recording and reproducing video signals and PCM audio signals, switches 6, 7, and 10 are switched by the switching circuit 20, and the PCM audio signal is recorded and reproduced on track 1 and the video signal is recorded and reproduced on tracks 2 to 6. .

In addition, the above example uses the delay time when performing after-recording, but the data information recorded on two or more tracks may have a time difference (delay time) due to some reason.
or when there is no original time difference but you want to delay it during playback (for example, when you want to delay the PCM audio signal in whole or in part with respect to the video signal recorded on tracks 2 to 6) ,
Furthermore, in cases where you want to delay data information recorded on one track with respect to a predetermined reference time rather than with respect to data information recorded on other tracks, the delay time can be used as an ID code. You can also record it.

〔effect〕

As described above, the present invention provides a magnetic recording and reproducing apparatus that divides an inclined track formed by a rotating head to be inclined with respect to the running direction of a magnetic tape into a plurality of tracks, and records and reproduces predetermined data information on each track. When the rotating head traces the magnetic tape once, it records and reproduces data information on two or more tracks, and also records and reproduces a code related to the combination of tracks for recording and reproducing data information together with the data information. Not only can four or more channels of data information be recorded and reproduced in synchronization with each other in a track 8 mm video tape recorder, etc., but also compatibility can be ensured with devices that can only record and reproduce two channels.

[Brief explanation of drawings]

FIG. 1 is a block diagram of the magnetic recording/reproducing apparatus of the present invention, and FIG.
4 to 4 are explanatory diagrams of the ID code, FIG. 5 is an explanatory diagram of converting the decimal number to binary number, FIG. 6 is an explanatory diagram of the combination method of tracks on the magnetic tape, and FIG.
This figure is an explanatory diagram of a conventional multi-trough magnetic tape, and FIG. 8 is an explanatory diagram of its recording signals. 1.16...Noise reduction circuit 2...A/D
Conversion circuit 3...10-8 Conversion circuit 4...Error detection and correction code generation circuit 5...Time axis compression modulation circuit 8.9...Rotary head 12...Time axis expansion demodulation circuit 13...・Error detection and correction circuit 14...8-10 conversion circuit 15...D/A conversion circuit 17...ID code input circuit 18...ID code reading circuit 19...Memory 20...Switching circuit that's all

Claims (4)

[Claims] (1) In a magnetic recording and reproducing apparatus that divides an inclined track formed by a rotating head to be inclined with respect to the running direction of a magnetic tape into a plurality of tracks, and records and reproduces predetermined data information on each track, the rotation When the head traces the magnetic tape once, the data information is recorded and reproduced on two or more of the tracks, and a code related to a combination method of the tracks for recording and reproducing the data information is recorded and reproduced together with the data information. A magnetic recording/reproducing device characterized by: (2) The inclined track is divided into a first track to a sixth track in the direction traced by the rotary head, and the first track and the second track are divided into the third track and the fourth track. The magnetic recording according to claim 1, wherein the tracks, the fifth track, and the sixth track are each combined, and in any combination, the running direction of the magnetic tape is the positive direction. playback device. (3) The inclined track is divided into a first track to a sixth track in the direction traced by the rotating head, and the first track, the third track, the fifth track, and the second track. track, the fourth track, and the sixth track are respectively combined, the running direction of the magnetic tape in the former combination is the forward direction, and the running direction of the magnetic tape in the latter combination is the forward direction or the reverse direction. 2. The magnetic recording/reproducing device according to claim 1, wherein the magnetic recording/reproducing device is in a direction. (4) the inclined track is divided into a first track to a sixth track in the direction traced by the rotary head, and the first track to the sixth track are combined;
2. The magnetic recording and reproducing apparatus according to claim 1, wherein the running direction of the magnetic tape is a forward direction.