JPS62264481A - Digital magnetic recording and reproducing method - Google Patents

Abstract

PURPOSE:To attain the reverse direction reproduction by making respective tracks into the locus of an information signal and changing over the regular direction recording/reproducing and the reverse direction recording reproducing for a prescribed track. CONSTITUTION:The number of rotation of a drum is made double compared with the conventional one, at an outward trip reproduction, a tape travelling direction is made into a normal direction and only for the track where outward trip information is recorded, an audio area is reproduced. At the return trip reproduction, the tape travelling direction is made into the reverse direction and the track only is reproduced in which return trip information is recorded. At the time of recording (reproducing), while a tape is made stationary, one track is recorded (reproduced), and before the next head starts to record (reproduce), the tape is proceeded for constant length L only. For example, since at a DAT, a lapping angle to a drum 2 of a tape 1 is 90 deg., while a head A3 is contacted with the tape 1, the tape is made stationary, the head A3 is separated from the tape, and while a head B4 is contacted with the tape 1, the tape is proceeded by a capstan motor only for the constant length L. Thus, without rewinding, reproduction can be continuously executed.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Industrial Application Field The present invention is for magnetic recording/reproduction using a rotating head such as a digital audio tape recorder (hereinafter abbreviated as DAT). do, especially P
CM Concerning the reverse playback method of tape recorders.

B1 Overview of the Invention A servo circuit that controls the rotational speed of the drum to double that of the conventional one, controls the stopping and feeding of the capstan motor, and a subcode detection that detects the forward or backward path and also switches the recording/playback amplifier. By a circuit and a controller that controls all of this.

PCM recording/playback method that allows recording/playback on the outward and return journeys.

C0 Prior Art Currently, C cassette (compact cassette) tape recorders and 8 mm VTRs are known as audio recording/reproducing devices using magnetic tape. These tapes have a plurality of tracks, so that once the tape has finished playing in one direction, it can be played back in the opposite direction, commonly known as auto-reverse.

The C cassette tape recorder has a fixed head and the first
Auto-reparse is made possible by providing two tracks, one in the forward direction and the other in the reverse direction, on the tape as shown in Figure 2.

In addition, in the multi-PCM playback method of an 8 mm VTR,
Although it is a rotating head, it is called multi-track and the first
As shown in Figures 3 (a) and (b), auto-reverse is possible between a maximum of 6 tracks. FIG. 13(a) shows the track direction, and FIG. 13(b) shows the reproduction direction.

D0 Problems to be Solved by the Invention However, apart from this, DAT has been devised as a rotating head type PCM recorder/player, which is smaller than the 8 mm VTR and has superior sound quality and operability. However, auto-reverse using the method shown in Figure 13 is D.
This is not possible due to the AT format.

An object of the present invention is to provide a digital magnetic recording/reproducing method that enables reverse direction reproduction in a rotary head type.

Means for Solving the E0 Problem In order to achieve the above object, the digital magnetic recording/reproducing method according to the present invention includes an audio signal obtained by compressing the time axis of each track and tape running information provided at the end of the audio signal. The gist is to change the trajectory of the information signal and to switch between forward recording/reproduction and reverse recording/reproduction for each predetermined track.

F6 action FIG. 3 is a plan view showing the positional relationship between the rotating drum and the tape. As shown, the tape 1 is normally in contact with the drum 2 over a distance of 90''. 3 is the head A, and 4 is the head B. , 5 is an arrow indicating the tape running direction, and 6 is an arrow indicating the drum rotation direction.

A in FIG. 4 shows a sampling data string obtained by sampling an audio signal. B and C are head output data strings at time T when head 2 is in contact with tape 1 . The N pieces of sampling data are time-compressed, and are recorded on the tape in units of N/2 at this time T in head ALC (head B).

B' and C' reduce the number of rotations of the drum by 2 compared to the conventional method.
This is the head output data string when the data is doubled.

As can be seen from the figure, by doubling the number of rotations of the drum compared to the conventional drum, the number of tracks (the number of times the drum contacts the tape) is doubled, making it possible to obtain recording tracks for the forward and backward paths.

In the present invention, recording is performed as shown in FIG. 4B' and C'.

G. EXAMPLES The present invention will be explained in more detail using examples below with reference to one drawing, but these are merely illustrative and various modifications and improvements can be made without going beyond the scope of the present invention. Of course it is possible.

FIG. 1 is a block diagram showing the configuration of an apparatus for carrying out the digital magnetic recording/reproducing method according to the present invention.
7 is an audio signal input terminal, 8 is an A/D conversion circuit, 9
, 10 is RAM A.

B, 11 is an encoding circuit, 12 is a clock generation circuit, 1
3 is a controller, 14 is a subcode generation circuit, 1
5 is an 8/10 conversion circuit, 16 is a 10/8 conversion circuit, 17
18 is a recording amplifier, 19 is a reproducing amplifier, 20 is a servo circuit, and 21 is a motor.

The controller 13 is configured as shown in FIG. In the figure, 22 is an input port, 23 is a RAM, 24
25 is a ROM, 25 is a CPU, 26 is an output port, and 27 is a timing control section.

The audio signal input from the input terminal 7 is converted from an analog signal to sampling data, which is a digital signal, by the A/D conversion circuit 8, and is recorded in the RAM (A) 9 or RAM (B) 10. This RAM switching is performed by the controller 13 every N pieces of sampling data.

While one RAM is recording sampling data, the other RAM is 8/10 after being encoded by the encoding circuit 11.
Data is output to the conversion circuit 15.

In addition to this sampling data, the 8/10 conversion circuit 15 also receives subcode data related to audio data from the subcode generation circuit 14 . For example, data such as time code and program number are input. The subcode generation circuit 14 outputs subcode data to the 8/10 conversion circuit 15 in accordance with the timing signal output from the controller 13 .

These data inputted to the 8/10 conversion circuit 16 are modulated using the 8/10 conversion modulation method, and then sent to the recording amplifier 18.
It is then recorded on tape 1.

In the servo circuit 20, an on/off signal for the remote motor 21 is inputted from the controller 13, and the motor 21
It also controls the drum motor to maintain the rotation speed of the drum 2 at twice the conventional speed, and controls the stopping and feeding of the capstan motor in synchronization with the rotation reference of the drum 2.

Here, the positions on the tape where audio data and subcode data are recorded will be explained.

In FIG. 5, b is an audio area where audio data is recorded, and a and Q are subcode areas (1) and (II) where subcode data is recorded.

It is.

Also, the track scanned by head A is called track A, and the track scanned by head B is called track B.

In this way, since the subcode area is located above and below the audio area, it is possible to record return information in the subcode area in advance during outbound recording, and record audio data in the subcode area during return trip recording. .

The digital magnetic recording/reproducing method according to the present invention will be specifically described below.

(i) In the case of outward recording, by doubling the rotational speed of the drum compared to the conventional method, sampling data can be recorded on 4 tracks in N sections, of which 2 tracks (B' in Figure 4) are recorded.
, C' (shaded area), N pieces of sampling data and forward route information are recorded as subcodes. The outward route information is 1, for example, tl OII. In the remaining two tracks, dummy data is recorded in the audio area and, for example, #1 FF is recorded as return path information in the subcode area.

A tape recorded in this manner is shown in FIG. 6(,). In the figure, the shaded area represents forward recording, and the white area in the audio area represents dummy recording.

(5) In the case of backward recording, the number of rotations of the drum is twice that of the conventional one, and the tape is run in the reverse direction.

First, start playing the subcode. Digital information recorded on the tape is reproduced by the head, passes through a reproduction amplifier 19 and is input to a 10/8 conversion circuit 16 . The input signal is demodulated in the 10/8 conversion circuit 16 and then input to the subcode detection circuit 17, where it detects subcode data and detects whether it is forward path or backward path information. This result is controller 13
is input.

When outbound route information is detected, the audio area is set to playback mode. When return trip information is detected, N/2 pieces of sampling data are recorded in the audio area.

A tape recorded in this manner is shown in FIG. 6(b). In the figure, each entry indicates an outgoing trip record, and one entry indicates a return trip record.

In this way, the forward and backward recordings are lined up for every two tracks of audio data. Further, along with this, outbound route information and return route information are recorded in the subcode area.

(iii) Operation explanation regarding reproduction The number of rotations of the drum is also twice that of the conventional one. In the outward playback, the tape running direction is set to the forward direction, and the audio area of only the tracks on which the outward path information is recorded is reproduced. In the backward playback, the tape running direction is reversed and only the audio area of the track where the backward path information is recorded is played back.

(iv) Explanation of tape feeding operation When recording (playing), one track is recorded (played) with the tape stationary, and the next head records (plays back).
Advance the tape a certain length (L) before starting.

This method is repeated to advance the tape. For example, in DAT, as shown in Figure 3, the drum of tape 1 is
Since the wrap angle for head A 2 is 90°, head A 3
However, while the head A 3 is in contact with the tape 1 (90°), the tape is held still, and the head A 3 separates from the tape and the head
Until B 4 comes into contact with tape 1 (90'''
The tape is advanced by a capstan motor by a certain length (L) every minute).

The constant length here refers to the distance between tracks in the longitudinal direction of the tape, as shown in FIG. In FIG. 7, the broken line represents the center line of the track.

The outward recording (reproduction) is as described above.

For return recording (playback), the tape feed is reversed.

Further, regarding reproduction, fine adjustment of tracking is also performed using an ATF (auto tracking finding) signal.

FIG. 8 is a flowchart showing a method for realizing the functions of the controller in the case of outbound recording. That is, the controller 13 shown in FIG. 2 operates as follows.

, (1) Command the servo circuit 20 to double the number of rotations of the drum compared to the conventional one.

(2) Input the head A detection signal from the timing control section 27. Wait until the signal turns on.

(3) When turned on, the subcode generation circuit 14
command to output outbound route information.

(4) Input the head A detection signal from the timing control section 27. Determine whether it is the next head A signal.

(5) If it is the next head A signal, the subcode generation circuit 17 is commanded to output return path information.

(6) Determine whether to end the outward recording operation.

If it does not end, repeat the following operations (2).

If finished, exit from this loop.

FIG. 9 is a flowchart showing a method for realizing the functions of the controller in the case of backward recording, and the controller 13 operates as follows.

(1) Command the servo circuit to double the drum rotation speed as before.

(2) A subcode detection signal is input from the subcode detection circuit 17, and it is determined whether the next signal is homeward information.

(3) If it is determined that it is return trip information, input an audio recording timing signal from the timing control section 27,
Wait until the signal turns on.

(4) When turned on, commands the amplifier switching signal to the recording side.

(5) Input an audio recording timing signal from the timing control unit 27 and wait until the signal is turned off.

(6) When turned off, it is determined whether or not to end the backward recording operation, and if not, the following operations (2) are repeated. If finished, exit from this loop.

The servo circuit 20 operates according to the flowchart shown in FIG.

The timing signal from the timing control section 27 is as shown in FIG. In the figure, (a) is a drum reference signal, (b) is a head A detection signal, (c) is head output data, (d) is an audio recording timing signal, and (e) is a one-track recording end signal.

As described in detail of the H0 invention, according to the present invention, by providing a return path, there is an advantage that continuous playback can be achieved without rewinding even when the tape reaches its end. Furthermore, since the conventional circuit configuration can be used almost as is, it can be easily implemented. Furthermore, if a normal time code is also recorded in the subcode area in addition to the outbound and return trip information (the recording capacity is sufficient), the remaining time can be accurately determined from the time code recorded in the outbound trip when recording the return trip. This prevents recording from ending in the middle of a song.

[Brief explanation of drawings]

Figure 1 is a plot diagram showing the configuration of an apparatus for carrying out the digital magnetic recording/reproducing method according to the present invention, Figure 2 is a block diagram showing the configuration of the controller, and Figure 3 is the positional relationship between the rotating drum and tape. FIG. 4 is a time chart for the conventional method and the method according to the present invention,
Fig. 5 is a diagram showing the positions of audio data and subcode data on the tape, Fig. 6 is a schematic diagram of the recorded tape, Fig. 7 is a plan view showing the positions of tracks on the tape, and Fig. 8 is a diagram showing the positions of the audio data and subcode data on the tape. FIG. 9 is a flowchart showing a method for realizing the functions of the controller in the case of outbound recording; FIG.
Figure 0 is a flowchart showing how to realize the functions of the servo circuit, Figure 11 is a timing chart of timing signals from the timing control section, Figure 12 is a plan view of a compact cassette tape, and Figure 13 is a multi-PCM playback of an 8 mm VTR. It is a top view of the tape in this system. 1...Tape, 2...Drum,
3...Head A, 4...Head B, 5...Arrow indicating the tape running direction, 6
・・・・・・ Arrow indicating the drum rotation direction, 7...
...Audio signal input terminal, 8...A/D conversion circuit, 9, 10...RAMA, B, 11
... Encoding circuit, 12 ... Clock generation circuit, 13 ... Controller, 14 ...
・・・Subcode generation circuit, 15 ・・・・・・ 8/
1° conversion circuit, 16...10/8 conversion circuit, 17...subcode detection circuit, 18...
...Recording amplifier, 19 ...Reproducing amplifier, 2
0... Servo circuit, 21... Motor, 22... Song/input port. 23...RAM, 24...ROM
, 25 ... CPU, 26 ... Output board, 27 ... Timing control section. Patent applicant: Clarion Co., Ltd. Genji V Flothe Mart Figure 1O

Claims (1)

[Claims] An information recording/reproducing method in which information is sequentially recorded on a tape or scanned and reproduced by a plurality of rotating heads that scan diagonally with respect to the tape running direction, comprising: (a) recording each track; It is characterized by a trajectory of an information signal including a time-axis compressed audio signal and tape running information provided at the end of the audio signal, and (b) switching between forward direction recording/playback and reverse direction recording/playback for each predetermined track. A digital magnetic recording/reproducing method.