JPH0719329B2 - Magnetic recording / reproducing device - Google Patents

Description

The present invention relates to a rotary head type magnetic recording / reproducing apparatus in which a tilted track of a magnetic tape is divided into a plurality of parts in the scanning direction of the rotary head, for example, an audio signal. The present invention relates to a device for recording and reproducing.

[Conventional technology]

5 to 7 are views relating to a conventional magnetic recording / reproducing apparatus. In FIG. 5, (1) is a rotary head drum,
(A) and (B) have an angle of 180 ° with each other,
A rotating head arranged on the rotating head drum (1),
(2) is almost diagonally on the peripheral surface of the rotating head drum (1).
A magnetic tape wound around 180 ° and designed to run in the direction of the arrow in the figure, (C) records or reproduces a control signal for tracking at the end of the magnetic tape (2). The control head (3) is a capstan for transferring the magnetic tape (2).

FIG. 6 is a schematic diagram of the magnetic pattern recorded on the magnetic tape (2), and the diagonal track in the figure is the rotating head (A).
And the tracks recorded in (B). The track indicated by the symbol A is recorded on the rotary head (A), and the track indicated by the symbol B is recorded on the rotary head (B). The magnetic pattern indicated by the symbol C is recorded by the control head (C).

FIG. 7 is a block diagram showing a main part of a recording / reproducing system for forming the magnetic pattern of FIG. 6 and reproducing a signal from such a magnetic tape, and (20) is a signal input terminal. , (21) is a recording processing circuit, (22) is a recording amplifier.
(23) is a signal output terminal, (24) is a reproduction processing circuit, (25)
Is a reproduction amplifier, (26) is a reference signal input terminal, (27) is a control signal recording circuit, (28) is a capstan control circuit, (29) is a capstan rotation detector, (30) is a capstan drive motor, ( 31) is a rotary head drum control circuit, (32) is a rotary head drum rotation detector, (33) is a rotary head drum drive motor, (34a), (34b), (34).
c) is a recording / reproducing switching switch, the symbol R is a recording side contact, and the symbol P is a reproducing side contact. A (or B) and C are the same as those shown in FIG. 5, and are a rotating head and a control head.

Next, the operation will be described. First, the operation during recording will be described.

Assuming that the input signal applied to the signal input terminal (20) is the video signal of the television here, the video signal is applied to the recording processing circuit (21) and signal processing suitable for recording on the magnetic tape, for example, After being subjected to FM modulation processing, this FM signal is applied to a recording amplifier (22) and amplified to an appropriate level. The output of the recording amplifier (22) is applied to the rotary heads (A) and (B) via the contact R of the switching switch (34a).

On the other hand, the reference signal input terminal (26) receives the reference signal for controlling the rotation of the capstan or the rotating head drum. Here, the vertical synchronizing signal included in the above video signal is separated and further Input the signal divided by 2 as the reference signal. A part of this reference signal is guided to the rotary head drum control circuit (31), where this signal and the rotary pulse derived from the rotary head drum rotation detector (32) are phase-compared and based on this phase comparison. The rotary head drum drive motor (33) is controlled by the comparison output. As a result, the head drum (1) rotates while locking to the reference signal.
A part of the above reference signal is used as a capstan control circuit (28).
Then, the phase of this signal is compared with the rotation pulse guided from the capstan rotation detector (29) via the contact R of the switching switch (34c), and the comparison output based on this phase comparison is performed. , Capstan drive motors (30)
To control. As a result, the captan (3) also rotates while locking to the reference signal, and the magnetic tape (2) runs at a predetermined speed. Further, a part of the reference signal is applied to the control signal recording circuit (27), where it is appropriately waveform-shaped and then guided to the control head (C) via the contact R of the switching switch (34b).

As described above, the video signal is alternately recorded by the rotary heads A and B by one field at a constant track pitch as diagonal recording tracks A and B as shown in FIG. 6, while the control signal C is recorded as two video signals. Each field is recorded on the control track at the end of the tape with equal pitch as shown in FIG.

Next, the operation during reproduction will be described.

The standard signal input terminal (26) is 1/2
A reference signal having a frequency substantially equal to the frequency of the divided vertical synchronizing signal is applied. As the reference signal, an oscillation signal of a stable crystal oscillator is usually used. A part of the reference signal is guided to the rotary head drum control circuit (31). Here, in the same way as described in the recording operation,
The rotating head drum (1) rotates by locking to the reference signal. Furthermore, part of the reference signal is the capstan control circuit (2
8) is applied. The other input to the capstan control circuit (28) is different from that at the time of recording, and the control signal recorded at the end of the magnetic tape (2) is reproduced from the control head (C) to switch the switch (34b) and (34c)
It is introduced through the contact point P of. Capstan control circuit (2
In 8), the reference signal and the reproduction control signal thus input are compared in phase, and the capstan drive motor (30) is controlled by this comparison output. As a result, the running phase of the magnetic tape (2) will be locked to the reference signal, and the rotating heads (A) and (B) will alternately scan over the tracks shown by the symbols A and B of the magnetic tape, respectively.

In this way, correct tracking is performed by the rotary heads (A) and (B) to reproduce the video signal,
This reproduction signal is guided to the reproduction amplifier (25) via the contact P of the switching switch (34a). The reproduction signal amplified by the reproduction amplifier (25) is applied to the reproduction processing circuit (24),
After processing such as FM demodulation here, output terminal (2
The original video signal is sent to 3).

Recording and reproduction of signals are performed as described above. In summary, it is configured to record diagonal tracks by the rotating magnetic head, record one control signal for every two diagonal tracks at the same time, and play the signal by playing the tracking of the rotating head with the control signal as a clue. Has been done.

[Problems to be solved by the invention]

Since the conventional magnetic recording / reproducing apparatus is configured as described above, the diagonal signal recording tracks are switched to, for example, audio, and each one track is divided into, for example, 5 channels, and the audio is divided into each channel. When trying to record a signal by time compression, if the control signal described above is recorded at the end of the tape every time it is recorded in each channel, it becomes impossible to determine which control signal corresponds to which channel during playback, Therefore, there is a problem that correct tracking cannot be performed.

The present invention has been made in order to solve the above problems. Even if a tilt track is divided into a plurality of channels and used for recording an audio signal instead of a video signal, the magnetic recording can be performed correctly. The purpose is to obtain a recording / reproducing apparatus.

[Means for solving problems]

A magnetic recording / reproducing apparatus according to the present invention is provided with a timing control circuit for generating a timing signal indicating a predetermined channel among a plurality of channels divided from an inclined track of a magnetic tape in a scanning direction of a rotary head, and synchronized with the timing signal. Then, the corresponding portion of the inclined track corresponding to the predetermined channel is recorded and reproduced, and further, when the first channel is recorded on the magnetic tape, the control signal is recorded, and when the next channel is recorded, the Tracking is performed using a recording control signal.

[Action]

Since the magnetic recording / reproducing apparatus according to the present invention is provided with the timing control circuit, the channel can be designated correctly at the time of recording / reproducing, and the control signal is recorded only when the first channel is recorded. Since the control signal is used for tracking, even if a plurality of channels are provided in one track, the control signal will not be confused and the tracking control of the existing magnetic recording / reproducing apparatus can be used as it is.

Example of Invention

An embodiment of the present invention will be applied to the case of recording / reproducing an audio signal, and the drawings will be described below. In Figure 1, (4
0) is a signal input terminal, and (41) is a signal processing for time-compressing the input signal to, for example, 1/5 and recording it in the 1/5 part while the rotating head makes a half rotation while contacting the tape. The recording processing circuit to be applied, (42) is a recording amplifier for amplifying the time-compressed signal generated by the recording processing circuit (41) to an appropriate level, (43) is a signal output terminal, and (44) is A reproduction signal processing circuit (45) which has a function opposite to that of the recording processing circuit (41), that is, a reproduction signal processing circuit for time-expanding the reproduction signal and restoring the original signal.
Is a reproduction amplifier that amplifies the signal reproduced from the rotary head, and (46) is a reproduction signal presence / absence determining circuit, which performs envelope detection of the reproduction signal from the rotary head, and if there is a reproduction signal, a high level (H ) If there is no output or reproduction signal, a low level (L) output is output. Reference numeral (47) is a recording / reproducing timing control circuit, which operates on the basis of the signal from the rotation detector (32) of the rotary head drum. (48) is a channel setting switch for setting a recording or reproducing channel.
(49a) and (49b) are switching switches, and the contact is set to the M side when the time compression signal is recorded. (26) ~ (34
a), (34b), (34c) and AC are the same as in FIG.

Next, the operation will be described.

First, the case of recording the time-compressed signal on the magnetic tape for the first time will be described. First, the switching switches (49a) and (49b) are tilted to the M side. Further, the switching switch (48) at this time is set to a desired channel, for example, CH1, and the signal to be recorded at the input terminal (40) and the reference signal at the input terminal (26) are input. The rotary head drum control and the capstan control operate in exactly the same manner as described in the conventional example, but will be briefly described again.

Regarding the capstan, when the changeover switch (34c) is on the R side, the magnetic tape is controlled to run at a constant speed by locking and rotating to the reference signal, and the changeover switches (34b) and (34c) are set to P If it is on the side, the running of the magnetic tape is controlled so that the control signal reproduced from the magnetic tape is locked to the reference signal.

On the other hand, the rotating head drum is controlled so as to always rotate by locking to the reference signal. This will be described with reference to FIG. 4. FIG. 4 (G) is a reference signal, and FIG. 4 (F) is a signal that schematically represents the rotation pulse obtained from the rotary head drum rotation detector (32). Both are always locked with a predetermined phase difference. The schematic rotation pulse (F) is at the H level while the rotating head (A) is in contact with the magnetic tape for half rotation, and is at the L level while the rotating head (B) is in contact with the magnetic tape for half rotation. Has been adjusted to

Now, for example, an audio signal is applied to the input terminal (40). An example of the input signal is shown in FIG. This signal is applied to the recording processing circuit (41), where it is converted into a PCM signal by analog-to-digital conversion (A / D) or the like, and a time compression operation is performed by increasing the reading speed from the writing speed of the memory circuit. The timing of the time compression signal output from the recording processing circuit (41) is controlled based on the signal shown in FIG. 4 (D) output from the timing control circuit (47). In this case, the timing corresponds to CH1. Is output. The outputs of the time-compressed signals at this time are shown in FIGS. 4 (B) and (C). This output is the recording amplifier (4
It is widened in 2) and guided to the switching switch (34a). The switching switch (34a) is switched to the R side in synchronization with the timing of the time compression signal by the output of the timing control circuit (47), so that the time compression signal is guided to the rotary head,
Recording is alternately performed on the magnetic tape by the rotating heads (A) and (B). The output of the timing control circuit (47) switches the switching switch (34a) to the R side only at the timing of recording CH1 as described above, but otherwise switches the switching switch (34a) to the P side. When it is switched to the P side, the playback outputs of the rotary heads (A) and (B) are guided to the playback amplifier (45) to be amplified during that time. Now, consider the case of the first recording. Therefore, since the reproduction output does not actually exist, the output of the reproduction amplifier (45) is zero. The output of the reproduction amplifier (45) is guided to the reproduction signal presence / absence determination circuit (46) and subjected to envelope detection. In this case, since there is no reproduction output, the output of the determination circuit (46) is shown in FIG. ) Output L level. This output is sent via the M contact of the switching switch (49b) to the switching switch (3
It is applied to 4b) and (34c) and makes its contact point to the R side.

As a result, the capstan rotates while rotating to the reference signal, and at the same time, the control signal recording circuit (27) records the control signal synchronized with the reference signal on the magnetic tape by the control head (C). This state is shown in FIG.

As described above, the time-compressed audio signal is recorded at the portion indicated by CH1 as shown in FIG. 2 in the 1/5 division portion of the above-mentioned diagonal track, and at the end of the tape. The control signal is recorded.

Next, a case will be described in which another signal is recorded on an empty channel of a tape on which a channel such as CH1 has already been recorded. Tilt the switching switch (48) to, for example, CH2, apply the signal to be recorded to the input terminal (40), and input the input terminal (26).
The same reference signal as described above is input to. In this case as well, the operation of each part is almost the same as that described above, but the output of the timing control circuit (47) is at the timing shown in FIG. 4 (D '), and the switching switch (34a) is operated only when recording CH2. Switch to the R side. Further, the output obtained from the recording processing circuit (41) also outputs a time compression signal during the period corresponding to CH2 based on the output of the timing control circuit (47). On the other hand, above CH2
Since the switching switch (34a) is on the P side except during the period corresponding to, the outputs of the rotary heads (A) and (B) are guided to the regeneration amplifier (45) except during the period of CH2. If there is a recording part on some channel, a replay amplifier (45)
A signal output is obtained at the playback signal presence / absence determining circuit (4
When applied to 6), the H level output shown by the broken line in FIG. 4 (E) is generated. By this H level output, the switching switches (34b) and (34c) are switched to the P side. Therefore, the capstan is controlled by the reference signal and the already recorded control signal, so that another time-compressed signal is recorded on the already recorded extension of the oblique track. This situation is shown as CH2 in FIG.

The same applies when recording CH3, CH4, and CH5 below.

FIG. 3 shows a state in which all channels are recorded in this way.

This is as if five signal input terminals and five recording processing circuits were provided in parallel, and time-compressed signals with different timings for each channel were collectively created for each track, and they were created as shown in FIG. It can be considered to be equivalent to a method in which a signal train as shown in C ') is created and recorded in the entire diagonal track as in the case of the conventional video signal recording, and the corresponding control signal is simultaneously recorded.

When reproducing the signal recorded as described above, first, the switching switches (34a), (34b) and (34c) are forcibly set to P.
Tilt it to the side and tilt the switch (48) to the desired channel. At this time, the capstan and the rotary head drum are controlled in the same manner as in the conventional example, and proper tracking is performed. The signals reproduced from the rotary heads (A) and (B) are amplified by the reproduction amplifier (45), and then the reproduction processing circuit (4
4) is applied. In the circuit (44), a desired channel time-compressed signal is selected by the output of the timing control circuit (47), further expanded in time and restored to the original signal, and the desired signal is obtained at the output terminal (43). .

In the above embodiment, the input signal is described as a voice signal, but other signals may be used.

Further, in the above-mentioned embodiment, the tape is sent in the same direction for both CH1 to CH5 for recording.However, any one of the channels is reversely fed, for example, CH1, CH3, CH5 are sent in the forward direction, and CH2, CH4 are fed. May be recorded as reverse feed.

〔The invention's effect〕

As described above, according to the present invention, since the common control signal can be used for a plurality of channels obtained by dividing the inclined track, the tape format of the conventional device can be used as it is and the tracking can be performed by the conventional circuit. Can be used at low cost, and a magnetic recording / reproducing apparatus capable of highly accurate recording / reproducing can be obtained.

[Brief description of drawings]

FIG. 1 is a block diagram showing a magnetic recording / reproducing apparatus according to an embodiment of the present invention, FIGS. 2 and 3 are diagrams showing magnetic patterns recorded according to the embodiment of the present invention, and FIG. FIG. 5 is a waveform diagram for explaining the operation of the embodiment of the invention, FIG. 5 is a block diagram showing the relationship between the rotating head and control head and the magnetic tape in the magnetic recording / reproducing apparatus, and FIG. 6 is recorded by the conventional apparatus. Figure showing the magnetic pattern
The figure is a block diagram showing a conventional device. In the figure, A and B are the rotating heads, C is the control head, and (34
Reference numerals a), (34b) and (34c) are switching switches, (46) is a reproduction signal presence / absence determining circuit, and (47) is a timing control circuit. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (2)

[Claims] 1. A plurality of rotary heads sequentially form and record tracks inclined with respect to the running direction of a magnetic tape, and a plurality of rotary heads reproduce the recorded signals of the inclined tracks, and a fixed head. A magnetic recording / reproducing apparatus for forming and recording continuous control tracks in the running direction of the magnetic tape, and reproducing a recorded control signal of the control track by a fixed head to track the magnetic tape. A timing control circuit that generates a timing signal indicating a predetermined channel among a plurality of channels divided in the scanning direction of the head, and the rotary head is switched to the recording side in synchronization with the predetermined channel of the timing signal and the other channel. The period is the first to switch the rotary head to the playback side. And a discriminating circuit for detecting the presence or absence of the recorded signal reproduced by the rotary head, and if the discriminating circuit detects the absence of the recorded signal, the fixed head is switched to the recording side to detect the presence of the recorded signal. A magnetic recording / reproducing apparatus provided with a second switching means for switching the fixed head to the reproducing side if detected. 2. The magnetic recording / reproducing apparatus according to claim 1, wherein the timing control circuit generates the timing signal in synchronization with the rotation signals of the plurality of rotary heads.