JP3014837B2 - 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 an insert or the like.

[0002]

2. Description of the Related Art As a helical scan type magnetic recording / reproducing apparatus for converting an analog video signal into a digital signal for recording / reproducing, for example, "Broadcasting Technology" 1990 Vo
l. 43No. 12 pp. 9-13 and PP. 51-
Conventionally, as described in FIG.
2. Description of the Related Art A digital magnetic recording / reproducing apparatus called a "-2 format" is known. Here, a D-2 format digital magnetic recording / reproducing apparatus (hereinafter referred to as DVTR) will be briefly described.

In a DVTR, as shown in FIG.
On the rotating cylinder 1, two adjacent reproducing heads (PBA, PBB) having different azimuth angles and two adjacent reproducing heads (PB
C, PBD) are mounted at 180 ° opposite to each other via an electromechanical conversion element, which can be displaced in parallel to the rotating cylinder axis by these electromechanical conversion elements. Similarly, on the rotating cylinder 1, two adjacent recording heads (RECs) having different azimuth angles are provided.
A, RECB) and two adjacent recording heads (RECC, RECD) having the same different azimuth angles
The recording head (RECA, RECB) and the recording head (RE
CC, RECD) are the reproduction heads (PBA, PB
B) and (PBC, PBD) are shifted by 90 °.

[0004] Incidentally, the reproducing heads (PBA, PBB, PB
C, PBD) have a gap length of 0.2 to 0.4 μm, and the recording heads (RECA, RECB, RECC, REC)
CD) has a gap length of 0.6 to 1.0 μm.

[0005] Although not shown, a magnetic tape is wound around the rotary cylinder 1 for about 180 ° and travels, and one pair of recording heads (RECA, RECB) is simultaneously rotated by a half rotation of the rotary cylinder 1. And the recording heads (RECC, RECD) form the other pair by scanning the magnetic tape in the next half rotation of the rotary cylinder. Recording head (RECC, RE
And CD) alternately form tracks on the magnetic tape.
Since recording is performed simultaneously by the two recording heads, two tracks are simultaneously formed on the magnetic tape.

FIG. 7 shows a track pattern on a magnetic tape on which recording has been performed in this manner. On such a magnetic tape, one field of video data has six tracks (a rotating cylinder). 1 (1.5 rotations). In addition to the digital video data, 4-channel digital audio data is recorded on both ends of the track. Other analog audio signals, control
(CTL) signal and time code signal, respectively.
There are two linear tracks.

In such a DVTR, since the reproducing head is a movable head, it is possible to always obtain a correct tracking state for a track to be reproduced by performing feedback control by comparing the level of a reproducing signal. it can. However, since the recording head is a fixed head, the tracking position with respect to the already recorded track is determined by the accuracy of the initial mechanism. For this reason, when editing an insert or the like, continuity between a newly recorded track and an old recorded track cannot be maintained in the portion of the continuous shooting. The reasons are: 1. The positional relationship between the recording head and the control pulse detection head varies depending on the individual DVTR. The deviation of the track position due to a change over time, a temperature change, or the like is caused.

If the continuity is not maintained as described above, a part of an old recorded track which must be left in a continuous shooting portion is cut off by a newly recorded track, or is recorded again and erased. Data of old tracks that must be erased. If this occurs, an uncorrectable error will occur in the digital data to be reproduced, and the reproduced image will be degraded in the joint shooting portion.

In order to eliminate such a problem, conventionally, as shown in FIG.
In the variable edit mode, the section from the PREROLL point before the IN point to the IN point is defined as a phase adjustment section in which the variable speed mode and the standard playback mode are set.
The two DVTRs are activated simultaneously to a predetermined standard tape speed (1x speed). Thereafter, in the standard reproduction mode, the level of the reproduction signal is detected while performing the reproduction by the recording head in the DVTR for insert editing. The magnitude is compared, and the capstan motor is controlled so that the level increases sequentially and becomes maximum. As a result, the recording head moves little by little in the direction of the track, and when the level of the reproduction signal becomes maximum, the recording head enters a good tracking state on the track.

[0010]

However, when the above-described tracking control of the recording head is performed, the recording head transitions with a step width of the minimum tracking movement amount T, so that the recording head changes as shown in FIG. As described above, while the magnetic head is initially in the state 1, the recording head transitions from the states 1, 2,... By the minimum tracking amount T so that the reproduction signal level of the recording head shown in FIG. Even if it best matches the track (state 4 in FIG. 10 where the reproduction signal level is maximum in FIG. 10), the recording head again transitions by the tracking minimum movement amount T and stops (state 5 in FIG. 10). Become. For this reason, the magnetic head is stabilized in a state where it is deviated by the minimum tracking movement amount T from the state in which the magnetic head best matches the track. FIG.
As shown in (b), the magnetic head is initially in state 6, and transitions from state 6, 7,... By the minimum tracking movement amount T so that the reproduction signal level of the recording head shown in FIG. Even if it matches the track best (in FIG. 10, the state of 9 shown in FIG. 10 which is smaller than the minimum tracking movement amount T at which the reproduction signal level becomes maximum).
The recording head again transitions by the tracking minimum movement amount T and stops (state 10 in the drawing). For this reason, the magnetic head is stabilized in a state where it is deviated from the state best matching the track by an amount smaller than the minimum tracking movement amount T.

As described above, the state in which the recording head is stabilized according to the tracking start phase between the magnetic tape and the recording head changes as shown in states 4 and 9 in FIG. The tracking state of the recording head is not the best. Such a state occurs because it is not possible to detect a tracking value having the maximum reproduction output level with an accuracy of the tracking minimum movement amount T or less. That is, when performing the tracking operation of the recording head, a tracking error of a maximum ± T / 2 is generated as a physically worst value with respect to the maximum tracking value of the reproduction output level.

For this reason, when insert editing is performed a plurality of times, insert editing is performed again in the area where the insert editing was performed last time, and tracking control of the recording head is performed using the track obtained by the previous insert editing. Sometimes, the track formed by this recording head is shifted from the track by the previous insert editing by the maximum tracking minimum movement amount T.

Therefore, when the above-mentioned insert editing is repeated for the same area on the magnetic tape, tracking of a maximum of ± T / 2 which occurs at the time of each insert editing for the track formed first on this magnetic tape is performed. They are accumulated, and the track continuity cannot be maintained.

In the DVTR, as shown in FIG. 11, each track on the magnetic tape has recording areas (hereinafter, referred to as audio areas) A1, A2, A3, and A4 for recording digital audio signals in two channels at both ends. A recording area for video data (hereinafter referred to as a video area) is provided between the audio areas. When the recording heads RECA and RECB simultaneously scan adjacent tracks by a half rotation of the rotary cylinder, the recording RECC is recorded in the next half rotation. , RECD
Scans the next adjacent separate track at the same time. In this way, the recording head is sequentially scanned by two tracks at a time.

[0015] Therefore, if insert editing is repeatedly performed only on a video signal in the same area of the magnetic tape, only the video area of each track is sequentially rewritten, and a shift occurs between the video area and the audio area.

This will be described with reference to FIG.
Is a track recorded first, T2 is a track recorded in the first insert edit, Tn is a track recorded in the nth insert edit, V is a video data recording area (hereinafter referred to as a video area), A1, A2, A
3 and A4 are digital audio data recording areas (hereinafter referred to as audio areas) of the respective channels, and when the first video signal insert editing is performed on the track T1, like the track T2,
The video area V is shifted from the audio area by the tracking error T at the maximum. And n
When the insert editing of the video signal is repeatedly performed on the same area on the magnetic tape, the video area V is shifted from the audio area by n times the maximum tracking error T like the track Tn.

As described above, when insert editing is performed by the above-described recording head tracking method, the track formed by this method is shifted from the initially formed track, and the insert editing is performed several times. If this is the case, the shift amount is small and there is no special effect on the reproduced image of the continuous shot portion, but if insert editing is performed many times repeatedly, the shift amount becomes considerably large, and the reproduced image deteriorates in the joint shot portion I do.

An object of the present invention is to provide a magnetic recording / reproducing apparatus which can solve such a problem and can prevent deterioration of track continuity due to editing.

[0019]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention is directed to a recording head which reproduces a plurality of signals on each track from a magnetic tape which is recorded in different blocks. A plurality of level detecting means for detecting the level of a signal for each block, and a selecting means for selecting any of the detection level signals of the level detecting means. A tracking control signal for the recording head is generated.

[0020]

Each track on the magnetic tape is divided into a plurality of blocks, and different types of signals are recorded on the respective blocks. When insert editing is performed on a desired signal with such a magnetic tape, rewriting is performed in a block corresponding to the signal. Prior to this, of signals reproduced from a track by a recording head, a signal to be inserted and edited is used. The levels of the reproduced signals of the blocks with respect to other signals are detected, and these levels are calculated to generate a tracking control signal for the recording head.

Therefore, if the recording head is controlled by the tracking control signal, the recording head will track a block on the track where a signal not to be subjected to insert editing is recorded. If the state is maintained, the block in which the signal is recorded by the recording head is formed while maintaining linearity with other blocks during the insert editing operation.

[0022]

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 recording heads, and 4 is a cylinder TP (tachymeter).
Pulse) detection head (hereinafter referred to as a cylinder TP detection head), and 5 is a cylinder FG (Frequency).
Generator head, 6 is cylinder TP
An amplifier, 7 is a cylinder FG amplifier, 8 is a phase comparison circuit,
9 is an fv (frequency voltage) conversion circuit, 10 is a vertical synchronization pulse generation circuit, and 11 is REF
(Reference) pulse generating circuit, 12 is a cylinder motor amplifier, 13 is a magnetic tape, 14 is CTL (C
ontrol) pulse detection head, 15 is a capstan FG detection head, 16 is a capstan rotation axis, and 17 is a CT
L recording amplifier, 18 a CTL reproduction amplifier, 19 a frequency dividing circuit, 20 a capstan FG amplifier, 21 an fv conversion circuit, 22 a capstan motor amplifier, 23 a phase comparison circuit, 24 a variable delay circuit, 25 Is a tracking controller, 26 is a system controller, 27, 28, 29 are switches, 30, 31 are addition circuits, 32 is a cylinder motor, and 33 is a capstan motor.

As shown in FIG. 6, recording heads (RECA, REC) are provided on a rotary cylinder 1 as shown in FIG.
B), (RECC, RECD) and playback head (PBA,
PBB) and (PBC, PBD) are provided, the recording head 1 is a recording head (RECA, RECB), the recording head 2 is a recording head (RECC, RECD), and a reproducing head is not shown.

During recording, the switches 27, 28 and 29 are closed on the REC side. Cylinder TP indicating rotation phase of recording heads 1 and 2 generated by cylinder TP detection head 4
After the pulse is amplified by the cylinder TP amplifier 6, the phase is compared with the vertical synchronization pulse from the vertical synchronization pulse generation circuit 10 by the phase comparison circuit 8, and a phase control signal corresponding to the phase difference is generated. This vertical synchronization signal is obtained from a video signal to be recorded. A cylinder FG pulse generated by the cylinder FG detection head 5 and having a frequency proportional to the rotation speed of the rotary cylinder 1 is amplified by a cylinder FG amplifier 7 and then supplied to an fv conversion circuit 9. A speed control signal is generated according to the difference between the frequency of the FG pulse and the frequency of the cylinder FG pulse when the rotating cylinder 1 rotates at a specified rotation speed. The phase control signal and the speed control signal generated as described above are added by the adding circuit 30 and supplied to the cylinder motor 32 via the cylinder motor amplifier 12.

In this way, the speed of the cylinder motor 32 is controlled so as to rotate at a specified rotational speed, and the rotary heads 1 and 2 rotate in a predetermined phase relationship with the vertical synchronization pulse of the video signal to be recorded. Thus, the phase is controlled.

At this time, the vertical synchronizing pulse output from the vertical synchronizing pulse generation circuit 10 is amplified by the CTL recording amplifier 17, supplied to the CTL head 14 via the switch 29, and placed on the magnetic tape 13. Recorded as a CTL pulse.

On the other hand, a capstan FG pulse having a frequency proportional to the rotation speed of the capstan motor 33 generated by the capstan FG head 15 is amplified by the capstan FG amplifier 20 and then divided by the frequency dividing circuit 19 and fv. It is supplied to the conversion circuit 21. In the frequency dividing circuit 19, the capstan FG pulse is frequency-divided, and the frequency-divided output pulse is supplied to the phase comparing circuit 23 via the switch 28. Also,
In the fv conversion circuit 21, the supplied capstan FG
A speed control signal corresponding to the difference between the pulse frequency and the frequency of the capstan FG pulse when the capstan motor 33 rotates at a specified rotation speed is generated. The REF pulse output from the REF pulse generation circuit 11 is delayed for a predetermined time by the variable delay circuit 24, and then supplied to the phase comparison circuit 23, where the REF pulse is compared with the output pulse of the frequency division circuit 19, and
A phase control signal corresponding to these phase differences is generated. The phase control signal and the speed control signal from the fv conversion circuit 21 are added by the addition circuit 31 and supplied to the capstan motor 33 via the capstan motor amplifier 22.

Thus, the capstan motor 33
Is controlled so as to rotate at a prescribed rotation speed, and is phase controlled so as to rotate in a predetermined phase relationship with the REF pulse from the REF pulse generation circuit 11.

When the magnetic tape 13 recorded by itself is reproduced by the recording heads 1 and 2 during insert editing,
The switches 27, 28 and 29 are closed to the PB side. The control of the cylinder motor 32 is performed by using the R signal from the REF pulse generation circuit 11 instead of the vertical synchronization pulse from the vertical synchronization pulse generation circuit 10 as a reference signal supplied to the phase comparison circuit 8.
The difference is that the EF pulse is used, but the other points are the same as in the recording, so that the description is omitted.

Regarding the control of the capstan motor 33, since the speed control is the same as that at the time of recording, the description thereof is omitted, and the phase control will be described.

The rotation of the capstan 16 driven by the capstan motor 33 causes the magnetic tape 13 to travel, and the CTL head 14 is moved from its control track.
Thus, the CTL pulse is reproduced. The CTL pulse is amplified by the CTL reproduction amplifier 18 through the switch 29, and further supplied to the phase comparison circuit 23 through the switch 28. On the other hand, RE from the REF pulse generation circuit 11
The F pulse is supplied to the phase comparison circuit 23 after being delayed by the variable delay circuit 24 for a predetermined time. In the phase comparison circuit 23, the REF pulse and the CTL pulse from the CTL reproduction amplifier 18 are compared in phase, and a phase control signal corresponding to the phase difference is generated. The following is the same as during recording, and the capstan motor 33 rotates at a predetermined rotation speed.
And the reproduced CTL pulse is a REF pulse generation circuit 1
The REF pulses from 1 have a predetermined phase relationship,
Controlled.

As described above, the cylinder motor 32 and the capstan motor 33 are controlled during recording and reproduction. When the magnetic tape 13 is recorded on another DVTR, recording is performed between the DVTRs. Since the distances between the heads 1 and 2 and the CTL pulse detection head 14 are different, if the same control as when reproducing the magnetic tape recorded by itself as described above is performed, the recording heads 1 and 2 will Scan from the track.

To this end, a variable delay circuit 24, a tracking adjustment unit 25, and a system controller 26 are provided. When a tracking shift between the recording heads 1 and 2 is detected, the system controller 26 sets the tracking adjustment unit 2
5 to change the delay time of the variable delay circuit 24 according to the tracking deviation amount, thereby controlling the running phase of the magnetic tape 13. Thereby, the recording heads 1 and 2 and CT
The deviation of the distance from the L pulse detection head 14 is compensated.

However, during recording and during reproduction by the reproducing head, the delay amount of the variable delay circuit 24 is fixed at a predetermined value.

By the way, in the conventional DVTR, as described above, the positional relationship between the recording head and the control pulse detecting head by each DVTR, the change with time, and the like.
The track position continuity cannot be maintained in the joint shooting portion due to a track position shift due to a temperature change or the like. In particular,
When on-track information when repeatedly performing insert editing on the same track is used to obtain tracking information based on a reproduction signal from a track on which insert editing has been performed last time, a tracking error generated by the previous insert editing is corrected by using the current insert editing. The resulting minimum tracking error T is accumulated, and the linearity on the track cannot be maintained.

Therefore, if tracking information is obtained from a reproduction signal from a track on which insert editing has not been performed and insert editing is performed using this information, accumulation of tracking errors may occur even if insert editing is repeatedly performed. In other words, the deviation between the track that is not insert-edited and the track that has been insert-edited is, at worst, a deviation of only the minimum tracking error T, regardless of the number of insert edits. In order to realize this, in this embodiment, the system controller 26 is set before the insert editing start time (the IN point in FIG. 8).
Controls the tracking adjustment unit 25 to adjust the amount of delay of the variable delay circuit 24. Accordingly, the running phase of the magnetic tape 13 is controlled so that the recording heads 1 and 2 use the old recorded tracks on the magnetic tape 13. On track. Hereinafter, a description will be given of the tracking adjustment unit 25 which is the center of this embodiment for enabling such an operation.

FIG. 2 is a block diagram showing a specific example of the tracking adjustment section 25. Reference numeral 34 denotes a preamplifier / E.
Q (Equalizer), 35 is an envelope detection circuit, 36
40 to 40 are sample hold circuits, 41 is an A / D (analog / digital) conversion circuit, 42 is an arithmetic circuit, 43 is a switch, 44 is a memory, 45 is a reproduction signal level comparison circuit, 46 is a tracking direction circuit, 47 Is a selection circuit, 48 to 52 are sampling pulse generation circuits,
3 is a switch.

As shown in FIG. 6, the position of the four recording heads RECA to RECD mounted on the rotary cylinder 1 is based on the recording head RRCA.
The recording head RECB has a fixed width,
In the same manner, the recording head RECC is arranged with respect to the recording head RECB, and the recording head RECC is arranged with respect to the recording head RECD in the above relationship. ing.
As a result, the width of the track formed by such recording heads becomes smaller than the track width of these recording heads. For example, if the track width of the recording head is 45 μm, the width of the formed track is reduced to 39 μm.
In the case of recording in this manner, the reference is the recording head R
Since it is ECA, the tracking position may be obtained so that the reproduction output level of the recording head RCA becomes maximum.

Therefore, in this embodiment, as shown in FIG. 3, a switch 54 is provided in the signal system of the recording head RRCA, and a switching control signal SW from the system controller 26 is provided.
During recording, the switch 54 is switched to the recording amplifier 55 side so that the recording signal is transmitted to the recording amplifier 55 and the switch 5.
4 so as to be supplied to the recording head RRCA,
At the time of insert editing, switch 54 is set to amplifier /
By switching to the EQ 34 (the same as the amplifier / EQ 34 in FIG. 2), the reproduction signal of the recording head RRCA is supplied to the amplifier / EQ 34 of the tracking adjustment unit 25.

Therefore, in FIG. 2, the reproduction signal of the recording head RRCA is supplied to the amplifier / EQ 34, amplified and equalized in waveform as described above. Amplifier / EQ3
4 is subjected to envelope detection by a detection circuit 35,
The envelope signal ES is supplied to the sample-and-hold circuit 36.
~ 40.

On the other hand, five sampling pulse generating circuits 48, 49, 50, 51, 52 are provided, and sampling pulses SP1, SP2, SP3, SP
4. SP5 is output. Now, assuming that each track on the magnetic tape 13 (FIG. 1) is provided with two audio areas on both sides of the video area V as shown in FIG. SP1, SP2, SP3, SP4, and SP5 fall at the respective edges of the head switching control signal A of the recording heads 1 and 2 (FIG. 1) and fall at the timing shown. That is, the sampling pulse SP1 is substantially at the center of the scanning period of the audio area A1 and is equal to the sampling pulse S1.
P2 is approximately at the center of the scanning period of the audio region A2, sampling pulse SP3 is approximately at the center of the scanning period of the video region V, and sampling pulse SP4 is approximately at the center of the scanning period of the audio region A3.
Reference numerals 5 fall substantially at the center of the scanning period of the audio area A4.

The selection circuit 47 receives from the system controller 26 shown in FIG. 1 information indicating a target signal (video signal or digital audio signal of a predetermined channel) for which the user wants to perform insert editing. , Sampling pulses SP1, SP2, SP3, SP
4. A sampling pulse corresponding to the selection signal SL of SP5 is selected and supplied to a corresponding one of the sample and hold circuits 36 to 40.

When the sampling pulse is supplied from the switch 53, the sample and hold circuits 36 to 40 sample and hold the envelope signal ES from the envelope detection circuit 35 at the rising edge.

Here, when insert editing a certain channel or video signal of the digital audio signal on the track, the switch 53 selects a sampling pulse for a signal other than the signal to be inserted and edited by the selection circuit 47. . FIG. 5 shows a signal sampled and held in this manner when one signal is insert-edited. In FIG. 5, for example, if the digital audio signal in the audio area A1 (digital audio signal A1; hereinafter the same) is to be insert-edited, the selection circuit 47 (FIG. 2) outputs the audio signal A2. , A3, A4, and sampling pulses SP2 to SP5 so as to sample and hold the video signal V. Therefore, the sample and hold circuits 37 to 4 in FIG.
0 operates, and the audio signal A2 of the envelope signal
A3, A4, and a portion of the video signal V are sampled and held and supplied to the A / D conversion circuit 41.

When insert editing is performed on all signals recorded on a track, a sampling pulse corresponding to the longest signal in time among signals recorded on the track is used. Alternatively, when all signals have the same time, the switch 53 selects a sampling pulse for a signal recorded closest to the scan start point of the print head.

Alternatively, the selection circuit 47 does not select all signals other than the target signal for which the user intends to perform insert editing. An adjacent recorded signal may be selected.

The A / D conversion circuit 30 converts the sample and hold value from one of the sample and hold circuits 36 to 40 into digital data, and the arithmetic circuit 42 averages the digital data and averages the reproduced signal. Output the value. When the average reproduction signal value is output from the arithmetic circuit 42, the switch 43 and the switch a are closed, and the reproduction signal level comparison circuit 45 compares the average reproduction signal value with the value stored in the memory 44. Next, the switch 43 is closed to the b side, and the same average reproduction signal output from the arithmetic circuit 42 is rewritten with the previous value. Therefore, the reproduction signal level comparison circuit 45 compares the level of the current average reproduction signal value output from the arithmetic circuit 42 with the average reproduction signal value output from the arithmetic circuit 42 immediately before the current reproduction signal value. The output signal of the reproduction signal level comparison circuit 45 is the difference between these average reproduction signal values having a positive or negative sign, whereby the tracking direction circuit 46 generates a signal for determining the direction and magnitude of tracking as follows. . By the output signal of the tracking direction circuit 46, the delay amount of the variable delay circuit 24 (FIG. 1) is adjusted so that the following tracking is performed. That is, the reproduction signal level of the previous detection ≧ the reproduction signal level of the current detection..., The reversal of the previous tracking direction. The reproduction signal level of the previous detection <the reproduction signal level of the current detection.

By repeating the above operation, the level of the reproduction signal of the recording head RCA is maximized.
The running phase of the magnetic tape 13 is controlled by controlling the phase of the capstan motor 33 in FIG.

Since the tracking position is also the position where the recording head RCA is on-track with respect to the old recorded track, even if the insert editing operation is repeatedly performed, the data of the old recorded track is not lost. Old track data to be erased by newly recorded track data or to be overwritten and deleted.
This eliminates the erasure of data, and improves the playback image quality in the continuous shooting section.

The starting point of insert editing (I in FIG. 8)
N point) to the end point of insert editing (OUT point in FIG. 8)
During the recording operation up to, the tracking position set as described above is held as it is. Therefore, the newly recorded track maintains continuity with the old recorded track.

In the above embodiment, the magnetic recording / reproducing apparatus is a D-2 format VTR.
RT, for example, a normal analog VTR. When digital audio signals are overlap-recorded by a normal analog VTR, according to the present invention, insert editing of only video signals or digital audio signals can be performed while maintaining track linearity (continuity).

[0052]

As described above, according to the present invention,
Even if insert editing is repeatedly performed on the same track, the linearity between the tracks of the insert-recorded signal and the non-insert-recorded signal is maintained, and the reproduction image quality in the joint shooting portion is maintained. Deterioration can be greatly improved.

[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 block diagram showing a specific example of a tracking adjustment unit in FIG.

FIG. 3 is a diagram showing switching means of a recording system and a reproduction system for a predetermined recording head in FIG.

FIG. 4 is a waveform diagram showing a sampling pulse in FIG. 2;

FIG. 5 is a diagram illustrating a selection operation of a selection circuit in FIG. 2;

FIG. 6 is a diagram showing a head arrangement in a rotary cylinder in a D-2 format VTR.

FIG. 7 is an explanatory diagram showing a tape format of a D-2 format VTR.

FIG. 8 is a timing chart showing an insert editing operation.

FIG. 9 is a diagram illustrating a tracking operation of the recording head in the phase adjustment section of FIG. 8;

10 is a diagram showing a change in a reproduction signal level of a recording head due to the tracking operation in FIG. 9;

FIG. 11 is a diagram showing an example of a track pattern on a magnetic tape.

12 is a diagram showing track discontinuity when insert editing is repeatedly performed on the track shown in FIG. 11;

[Explanation of symbols]

 Reference Signs List 1 rotating cylinder 2, 3 recording head 11 REF pulse generation circuit 13 magnetic tape 16 capstan 23 phase comparison circuit 24 variable delay circuit 25 tracking adjustment unit 26 system controller 33 capstan motor 34 amplifier / EQ 35 envelope detection circuit 36-40 Sampling / hold circuit 41 A / D conversion circuit 42 Operation circuit 43 Switch B 44 Memory 45 Reproduction signal level comparison circuit 46 Tracking direction circuit 47 Selection circuit 48-52 Sampling pulse generation circuit 53 Switch

Continued on the front page (72) Inventor Hideo Nishijima 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Hitachi, Ltd. Visual Media Research Laboratories (72) Inventor Yuji Inaba 4--6, Kanda Surugadai, Chiyoda-ku, Tokyo Hitachi, Ltd. (56) References JP-A-64-82302 (JP, A) JP-A-2-203458 (JP, A) JP-A-4-311854 (JP, A) (58) Fields investigated (Int. . ^7, DB name) G11B 15/467

Claims (6)

(57) [Claims] 1. A recording head is fixedly provided on a rotating cylinder, and a plurality of signals different from each other are recorded on each track in a different block by a recording tape from the magnetic tape during insert editing. A magnetic recording / reproducing apparatus configured to reproduce the signal, generate a tracking control signal by detecting the level of the reproduction signal, and control the tracking of the recording head by the tracking control signal. A plurality of level detecting means for detecting a signal level of each block of each track; and a selecting means for selecting one of the detection level signals of the level detecting means. Generating the tracking control signal for the recording head from a level signal. apparatus. 2. The magnetic recording and reproducing apparatus according to claim 1, wherein the tracking control of the recording head by the tracking control signal is performed after a phase of a reproduction signal by the recording head reaches a predetermined phase. 3. The apparatus according to claim 1, wherein the selection means selects and selects the detection level signal for a reproduction signal from a block in which all signals other than the block of the signal to be inserted and edited are recorded. A magnetic recording / reproducing apparatus for calculating the tracking control signal of the recording head by calculating the detection level signal. 4. The apparatus according to claim 1, wherein the selecting means converts the detection level signal with respect to a reproduction signal from the block in which a signal adjacent or closest to the block of the signal to be inserted and edited is recorded. A magnetic recording / reproducing apparatus characterized by selecting. 5. The apparatus according to claim 1, wherein at the time of insert editing for all of the blocks, the selection means selects the detection level signal for a reproduction signal from a block having the longest time on the track. Magnetic recording and reproducing device. 6. The apparatus according to claim 1, wherein at the time of insert editing for all of the blocks, the selection means selects the detection level signal for a reproduction signal from a block closest to a scanning start point of the track. Magnetic recording and reproducing device.