JP2799093B2 - Magnetic recording / reproducing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a helical scan type magnetic recording / reproducing apparatus , and more particularly to automatic tracking at the time of editing such as insert editing and assembling editing.

[0002]

2. Description of the Related Art Conventionally, as a device for converting an analog video signal into a digital signal and recording / reproducing on a magnetic tape, for example, "D-2NTSC composite digital V" is conventionally used.
TR Television Society Technical Report, 11, 24, pp13
-18 (1987) ".
Alternatively, a digital magnetic recording / reproducing apparatus called a D-2 format is known.

Here, a digital magnetic recording / reproducing apparatus of the D-2 format (hereinafter referred to as DVTR) will be briefly described. As shown in FIG. 3, on the cylinder 1,
A reproducing head pair consisting of two adjacent reproducing heads (PB1, 2) having different azimuth angles and a reproducing head pair consisting of the same reproducing heads (PB3, 4) face 180 °, and the electromechanical transducer is Each reproducing head can be displaced in the cylinder axis direction by such an electromechanical transducer. The reproducing head that can be displaced in this manner is hereinafter referred to as a movable reproducing head. Similarly, on the cylinder 1, there are two adjacent recording heads (REC3, 4) having the same azimuth angle and two adjacent recording heads (REC1, 2) having the different azimuth angles. And a pair of recording heads, each of which is attached to the movable reproducing head pair by 90 °.
° Position is off.

The gap length of the movable reproducing heads (PB1 to PB4) is 0.2 to 0.4 μm, and the gap length of the recording heads (REC1 to REC4) is 0.6 to 1.0 μm.

A pair of recording heads composed of recording heads (REC1, 2) and a pair of recording heads composed of recording heads (REC3, 4) scan the magnetic tape alternately, and each recording head pair is simultaneously scanned by its own recording head. Form a track. Thereby, two channels, the channel by the recording head (PB1, 3) and the channel by the recording head (PB2, 4), can be recorded simultaneously.

FIG. 4 shows such recording heads (REC1 to REC4).
Is a track pattern formed on a magnetic tape according to the present invention, wherein a track formed obliquely to the longitudinal direction of the magnetic tape 13 is a video track, and a video signal comprises six tracks of data for each field. (1.
5 rotations) and recorded. In this video track, digital audio data of four channels is recorded in addition to the digital video data. On the magnetic tape 13, other three-channel linear tracks are formed, and an analog audio signal, a control pulse, and a time code signal are respectively recorded.

[0007]

In the DVTR, the electromechanical transducer is controlled so that the level of a reproduction signal from a track to be reproduced is maximized, and the movable reproduction heads (PB1 to PB4) are displaced. By the feedback control, the movable reproducing heads (PB1 to PB4) can always be brought into a correct tracking state with respect to the track to be reproduced.
4) are fixed to the cylinder 1 and their positions are determined by the accuracy of the initial mechanism. For this reason, at the time of editing such as insert editing or assemble editing, continuity of these tracks may not be maintained at the joint between a newly recorded track and an old recorded track. The reasons are: The positional relationship between the recording head and the control pulse detection head is different for each DVTR.

[0008] 2. The positional deviation of the recording track due to aging, temperature change, etc.

[0009]

As a result, the data of the old recorded track is erased by the newly recorded track at the seam between the old recorded track and the newly recorded track, or the data is erased by overlapping recording. The data of the old track to be deleted is left unerased. Therefore,
In such a case, an error occurs in the reproduced data, and the image quality is deteriorated in a portion of the reproduced image corresponding to the joint.

On the other hand, as a method for preventing the image quality of a reproduced image from being degraded at the joint portion, a track is reproduced by a recording head, a reproduced output level is detected, and a capstan motor is controlled based on the detected output. There has been proposed a method of causing a recording head to accurately track a recorded track by using a recording amplifier 101 used for recording at each recording head (REC1 to REC4) as shown in FIG. Side and the above recording heads (REC1 to REC1)
Switch means 100 for switching between the reproduction amplifier side 102 used at the time of tracking 4) and its control means are required. Therefore, the configuration of the apparatus becomes complicated and expensive.

As shown in FIG. 6, there is a recording amplifier 101 between each recording head (REC1-4) and the rotary transformer, and these recording heads (REC1-4).
In a DVTR dedicated to recording, there is no method for detecting the deviation of the recording heads (REC1 to REC4) from the recorded track, so that it is possible to control such that these are accurately tracked on the recorded track. Did not.

An object of the present invention is to provide a magnetic recording / reproducing apparatus which solves such a problem, enables a recording head to track a recorded track with a simple structure, and can perform editing correctly. Is to do.

[0014]

In order to achieve the above object, the present invention relates to a magnetic recording / reproducing apparatus having a tracking control means for setting a tape running phase in synchronization with a reference phase from a tracking adjusting means. At least record
Head and playback head are fixed on a rotating cylinder.
To the start of recording by the recording head.
A level for detecting a reproduction output level of the reproduction head beforehand.
Level detecting means and the level detecting means according to a detection result of the level detecting means.
Controlling the tracking adjusting means to reproduce the reproduction output of the reproducing head;
Final to generate the reference phase that substantially maximizes the level
Control means for setting and holding the tracking adjustment means in a state
At the start of recording by the recording head.
Output from the tracking adjustment means set to the final state.
The reference phase to be recorded is set in advance with the recording head and the recording head.
Correction means for correcting the amount of displacement corresponding to the raw head
And a step provided by the correction means.
The adjustment amount is determined by re-recording the magnetic tape recorded by the recording head.
Reproducing with a raw head, the recording head is attached to the magnetic tape.
The reference from the tracking adjustment means when recording with
Phase and the magnetic tape recorded by the recording head.
The reproduction output of the reproducing head when the reproducing head reproduces.
The tracking adjustment means for substantially maximizing the force level
From the difference from the reference phase.

[0015]

Since the reproduction output level of the reproducing head can be detected by the level detecting means, the control means controls the tracking adjusting means while monitoring the detection result of the level detecting means to change the reference phase of the tracking control means. Thus, the reference phase can be set such that the reproduction output level of the reproduction head becomes substantially maximum. At this time, the reproduction head is on-track to the recorded track on the magnetic tape. But the recording head
And the reproducing head are displaced on the rotating cylinder, so when the reproducing head is on-track to the recorded track, the recording head is displaced from this recorded track by an amount corresponding to this positional deviation. I have.

Therefore, in the present invention, the reference phase from the tracking adjustment means at this time is changed by the correction means by an amount corresponding to the position shift. This allows you to record
The head will track the recorded track.

For insert editing and assembly editing,
By performing such an operation before editing and recording, at the start of editing and recording, the recording head is on-track on the already-recorded track , thereby increasing the continuity between the already-recorded track and the newly-recorded track. Will be obtained.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of a magnetic recording / reproducing apparatus according to the present invention, wherein 1 is a rotary cylinder, 2 and 3 are non-movable reproducing head pairs, and 4 is a TP head (cylinder T).
P (Tachometer Pulse) detection head),
5 is a cylinder FG (Frequency Generator)
ter) detection head, 6 is a cylinder TP amplifier, 7 is a cylinder FG amplifier, 8 is a phase comparator, 9 is an fv (frequency-voltage) converter, 10 is a vertical synchronization pulse generator, 11
Is a reference pulse generator, 12 is a cylinder motor amplifier, 1
3 is a magnetic tape, 14 is a CTL (control) pulse detection head, 15 is a capstan FG detection head, 16 is a capstan rotation axis, 17 is a CTL pulse recording amplifier,
8 is a CTL pulse reproducing amplifier, 19 is a frequency dividing circuit, 20 is a capstan FG amplifier, 21 is an fv converter, 22 is a capstan motor amplifier, 23 is a phase comparator, 24 is a variable delay circuit, and 25 is a preamplifier / Equalizer, 26 is an envelope detector, 27 is a level detector, 28 is a memory,
9 is a system controller, 30 is a video signal processing unit, 3
1 to 35 are switches, 36 is an adder, 37 is a cylinder motor, and 38 is a capstan motor.

In FIG. 1, on the rotary cylinder 1, similarly to the rotary cylinder 1 shown in FIG. 3, movable reproducing heads (PB1 to PB4) and recording heads (REC1 to REC4) mounted via electromechanical transducers. ), And a pair of non-movable heads 2 and 3 composed of a reproducing head whose position is fixed with respect to the rotary cylinder 1 (hereinafter, referred to as a non-movable head) are attached. Here, these recording heads (REC1 to REC4) are dedicated to recording, and therefore, they are referred to as recording-only heads.

The arrangement of these heads on the rotary cylinder 1 is shown in FIG. That is, recording-only heads (REC1 to REC4)
The arrangement relationship between the recording and reproducing heads (PB1 to PB4) is the same as that in FIG. 4, except that the pair of recording and recording heads REC1 and REC2 and the recording and reproducing heads PB1 and PB
A reproducing head pair 2 is disposed between the reproducing head pair composed of the recording heads REC3 and REC4 and a reproducing head pair composed of the movable reproducing heads PB3 and PB4. 3 are arranged. Reproducing head pair 2 consists of two adjacent non-movable reproducing heads (CONF1, 2) having different azimuth angles, and reproducing head pair 3 has two adjacent non-movable reproducing heads (CONF3, 4) having different azimuth angles. ).

Returning to FIG. 1, at the time of recording, the switches 33, 34 and 35 are closed on the REC side. A vertical synchronizing pulse VS is formed from a video signal to be recorded by a vertical synchronizing pulse generating circuit 10 and is detected from the rotating cylinder 1 by the TP head 4 and the cylinder TP
The phase is compared by the phase comparator 8 with the cylinder TP pulse amplified by the pulse amplifier 6. The FG signal of the rotary cylinder 1 obtained from the cylinder FG detection head 5 is amplified by a cylinder FG amplifier 7 and then supplied to an fv converter 9 to be converted into a voltage corresponding to the rotation speed of the rotary cylinder 1. Is done. Phase difference output from phase comparator 8 and f−v
After being added to the output voltage of the converter 9 and amplified by the cylinder motor amplifier 12, it is supplied to the cylinder motor 37 to drive it. By this feedback control,
The phase difference output of the phase comparator 8 and the output voltage of the fv converter 9 are controlled so as to be constant, and therefore, the rotating cylinder 1 rotates in synchronization with the vertical synchronization pulse VS. Thus, the control of the rotary cylinder 1 is performed.

The vertical synchronizing pulse VS output from the vertical synchronizing pulse generating circuit 10 is amplified as a CTL pulse by a CTL pulse recording amplifier, and then supplied to the CTL head 14 via a switch 34, and It is recorded on the control track (FIG. 4) of the tape 13.

On the other hand, a capstan FG signal having a frequency proportional to the rotation speed of the capstan motor 37 is obtained from the capstan FG detection head 15. The capstan FG signal is amplified by the capstan FG amplifier 20, divided by the frequency divider 19, and supplied to the phase comparator 23 via the switch 35. This phase comparator 23 includes:
Further, a reference pulse REF output from the reference pulse generator 11 and delayed for a predetermined time by the variable delay circuit 24 is supplied. Therefore, in the phase comparator 23, the phase difference between the output signals of the frequency dividing circuit 19 and the variable delay circuit 24 is obtained, and the phase difference detection output is amplified by the capstan motor amplifier 22 and then sent to the capstan motor 38. Supplied to drive this. As a result, a phase loop at the time of recording for driving the capstan motor 38 is formed. The output signal of the capstan FG amplifier 20 is output from the fv converter 2
Is supplied to the 1 is converted into a voltage proportional to the rotational speed of the capstan motor 38, the output voltage is Kyapusutanmo
After being amplified by the data amplifier 22 , the capstan motor 3
8 to drive it. Thus, a speed loop at the time of recording for driving the capstan motor 38 is formed.

At the time of reproduction, the switches 33 to 35 are closed on the PB side. Thus, the phase comparator 8, the reference pulse REF from the reference pulse generator 11 instead of the vertical sync pulse from the vertical sync pulse circuit 10 is supplied, therefore, the rotary cylinder 1 is synchronized with the reference pulse REF Rotate.

Further, a CTL pulse is reproduced from the magnetic tape 13 by the CTL head 14, and the CTL pulse passes through the switch 34 and is amplified by the CTL pulse reproducing amplifier 18. The output pulse of the CTL pulse reproducing amplifier 18 is supplied to the phase comparator 23 via the switch 35 instead of the output signal of the frequency dividing circuit 19. Other points are the same as at the time of recording. Thus, the capstan motor 38 rotates in synchronization with the output pulse of the variable delay circuit 24.

Here, assuming that the magnetic tape 13 has recorded itself, the positional relationship between the recording-only head and the CTL head 14 does not change between recording and reproduction. By making the time and the reproduction equal, each recording-only head traces the track recorded by each recording head.

However, when reproducing a magnetic tape 13 recorded by another DVTR,
Since the distance between the CTL pulse detection head 14 and the recording-only head varies depending on R, if the same control as that of the magnetic tape recorded by itself is performed, the recording-only head is shifted from the recorded track and traced. I do. To prevent this tracking deviation, the system controller 2
9 to adjust the delay amount of the variable delay circuit 24, whereby the tape running phase is controlled and the CTL is controlled.
When a signal is detected, the recording head can be just-tracked. However, normally, the delay amount of the variable delay circuit 24 is set to a certain fixed value at the time of manufacturing adjustment.

Next, the operation of this embodiment in the case of insert editing or assemble editing will be described. As described above, the positional relationship between the recording-dedicated head and the control pulse detection head varies among the individual DVTRs, and track displacement on the magnetic tape due to aging, temperature change, or the like occurs. In this case, the continuity of these tracks cannot be maintained at the joint between the newly recorded track and the recorded track. To prevent this, the system controller 29 controls the tape running phase by adjusting the delay amount of the variable delay circuit 24 before the edit recording point in the insert edit or the assemble edit. It is necessary to make the recording-only head on-track on the old recorded track. In this embodiment, this can be realized, and the point will be described below.

As shown in FIG. 6, a recording-only head (REC)
If the recording heads (REC1 to 4) are exclusively for recording, it is not possible to obtain a reproduction output for determining whether or not these recording-only heads (REC1 to 4) are completely on-track. Therefore, in this embodiment, the non-movable reproducing heads (CONF.1 to 4) are provided on the rotary cylinder 1 as shown in FIG. To detect the tracking state of the recording-only heads (REC1 to REC4). In this case, the recording-only head (REC1-4) and the non-movable reproducing head (C
ONF. Although the position is shifted from that of the non-movable reproducing heads (CONF.1 to 4) as shown in FIG. By compensating for this deviation amount, the recording-only heads (REC1 to REC4) can be turned on the old recorded track.

Therefore, recording-only heads (REC1 to REC4)
In order to detect the displacement of the non-movable reproducing heads (CONF.1 to 4), the delay amount of the variable delay circuit 24 is set to a certain value in the manufacturing adjustment stage, and self-recording is performed in this state. The reproduced magnetic tape 13 is reproduced. However,
Here, the magnetic tape 13 due to a change over time, a change in temperature, or the like is used.
It is assumed that there is no positional deviation of the track at the time.

In this reproducing state, as described above, the capstan motor 38 rotates in synchronization with the reference pulse REF delayed by the variable delay circuit 24, and the magnetic tape 13 has the same running phase as during recording. As the vehicle runs, the recording-only heads (REC1 to REC4) respectively trace predetermined tracks on the magnetic tape 13 without tracking deviation. Non-movable reproducing head (CONF.1 to 4) at this time
Can be detected by the reproduced signals.

That is, in FIG. 1, the reproduced signals of the non-movable reproducing heads (CONF. 1 to 4) at this time are amplified by a preamplifier / equalizer 25 and optimized, and then detected by an envelope detection circuit 26. The level of the detection output level is determined by the level determiner 27. The result of this determination is supplied to the system controller 29. The system controller 29 adjusts the delay amount of the variable delay circuit 24 so that the reproduction signal of the non-movable reproduction heads (CONF. 1 to 4) becomes the maximum level based on the result of this determination.

The delay amount of the variable delay circuit 24 when the reproduction signal level of the non-movable reproduction heads (CONF. 1 to 4) obtained as described above is maximized, and the delay amount set at the time of initial recording. Is the recording only head (REC1-4)
The system controller 29 sets this as a tracking shift amount, switches the switch 31 to the A side, and stores it in the memory 28. At this time, the switch 32 is closed to the B side. Thus, the recording-only head (REC1 to REC4) and the non-movable reproducing head (CON
F. The data representing the positional deviation from (1) to (4)
Is stored.

As described above, such data is stored in the manufacturing adjustment stage, and in this state, good insert editing and assembly editing can be performed in this embodiment. Hereinafter, such an editing operation of this embodiment will be described. Will be described.

Insert edit or assemble edit mode
In this state, the magnetic tape 13 is cueed to the pre-roll point, and then enters the reproducing state. During the reproduction, the system controller 29 adjusts the delay amount of the variable delay circuit 24 as described above, regardless of the recording tape by the self-recording tape or another DVTR, and the non-movable reproduction head (CONF.1). 4) The reproduced signal is set to the maximum level. When this maximum level is obtained, the recording-dedicated heads (REC1 to REC4) are out of tracking from the determined track by the amount of tracking deviation.

When the reproduction signals from the non-movable reproduction heads (CONF. 1 to 4) reach the maximum level, the system controller 29 switches the switch 31 to the B side and the switch 32 to the A side, and The stored tracking error amount is read and supplied to the adder 33 via the switch 32, and the phase thereof is changed by the tracking error amount in addition to the output signal of the variable delay circuit 24.

In this way, the tape running phase is controlled, and the recording-only heads (REC1 to REC4) are brought into the on-track state on the old recorded track, and the edit recording start point in insert editing or assemble editing is started. In this example, the recording-only heads (REC1 to REC4) are in an on-track state on an old recorded track. Therefore, at the joint portion at the edit recording start point and the edit recording end point, the data of the old recorded track is erased by the newly recorded track, or the old data to be erased by the overwriting of the newly recorded track. The data of the recorded track will not be left unerased, and it is possible to prevent the deterioration of the image quality of the reproduced image at the joint.

[0038]

As described above, according to the present invention,
In a magnetic recording / reproducing apparatus in which insert editing and assemble editing are performed using a recording head , reproduction
Only by detecting the tracking state of the
Track from the start of recording to the recorded track.
With this simple structure, the continuity of the track position at the joint between the newly recorded track and the old recorded track can be maintained, and the image quality of the reproduced image at this joint can be reduced. Can be prevented.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of a magnetic recording / reproducing apparatus according to the present invention.

FIG. 2 is a plan view showing an arrangement relationship of each head in a rotary cylinder in FIG.

FIG. 3 is a plan view showing an arrangement relationship of respective heads in a rotary cylinder in a conventional magnetic recording / reproducing apparatus .

FIG. 4 is a diagram showing a tape format of a DVTR.

FIG. 5 is a circuit diagram showing an example of a signal transmission system near a recording-only head.

FIG. 6 is a circuit diagram showing another example of a signal transmission system near a recording-only head.

[Explanation of symbols]

 Reference Signs List 1 rotating cylinder 2, 3 non-movable reproducing head pair 11 reference pulse generating circuit 13 magnetic tape 24 variable delay circuit 27 level detector 28 memory 29 system controller 31, 32 switch 36 adder 37 cylinder motor 38 capstan motor

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hideo Nishijima 292 Yoshidacho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Inside the Visual Media Research Laboratory, Hitachi, Ltd. (72) Inventor Shigemitsu Higuchi 292 Yoshidacho, Totsuka-ku, Yokohama-shi, Kanagawa Hitachi, Ltd. Visual Media Research Laboratory (72) Inventor Yuji Inaba 2-15-12 Nishishinbashi, Minato-ku, Tokyo Hitachi, Ltd. High-Vision Strategic Development Division, Home Appliances Division, Hitachi, Ltd. (56) References JP2 -203456 (JP, A) JP-A-51-135509 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G11B 15/467

Claims (2)

(57) [Claims] At least a recording head is provided on a rotating cylinder.
And the playback head are fixedly mounted, and the reference phase is adjusted.
In the magnetic recording / reproducing apparatus provided with a tracking adjusting means for adjusting the running phase of the magnetic tape by adjusting the magnetic tape, the recording head is started before the recording by the recording head is started.
Level detecting means for detecting the head of the reproduction output level, in accordance with a detection result of said level detecting means and controls the state of the tracking adjustment means changing the reference phase, the regeneration
The tracking adjustment means is provided in a final state in which the reference phase which substantially maximizes the reproduction output level of the recording head is generated.
Control means for setting and holding , and when printing is started by the printing head, the head is held in the final state.
Correcting hand for correcting a predetermined adjustment amount set in advance the reference phase output from the lifting has been said tracking adjustment means
And a step , wherein the predetermined adjustment amount by the correction unit is adjusted by the recording head.
When the recorded magnetic tape is reproduced by the reproducing head
At the time of recording on the magnetic tape with the recording head.
The reference phase from the tracking adjustment means and the recording
The reproducing head reproduces the magnetic tape recorded by the read head.
The playback output level of the playback head when
The reference phase from the tracking adjustment means to maximize
Of the ones determined from the difference, the recording begins with the magnetic recording and reproducing apparatus of the recording head, characterized in that it has configured to be able to be on-track on the recorded track on the magnetic tape. 2. The method according to claim 1, wherein said tracking adjustment means generates a reference pulse having a constant reference phase.
Means for variably delaying said reference pulse and providing a reference for said predetermined reference phase
And variable delay means for outputting a pulse, and the reference phase of the reference pulse outputted from said variable delay means
Phase of control signal reproduced from the magnetic tape
And the traveling speed of the magnetic tape so that
Driving control means for controlling the degree
Magnetic recording and reproducing device.