JPH0514343B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an insert editing device, and more particularly, the present invention relates to an insert editing device, and in particular, a plurality of pilot signals having different frequencies are applied to recording tracks formed in sequence in a horizontal direction in the running direction on a recording medium. cyclically recorded along with the video signal,
The automatic track following method (hereinafter referred to as ATF) uses the pilot signal regenerated by the reproducing head to make the reproducing head track each track.
This method is suitable for application to an image recording apparatus of the above-mentioned method.

[Background technology and its problems]

Generally, in this type of image recording device, such as a video tape recorder (VTR), a desired section of a tape serving as a recording medium on which first image information has already been recorded is erased, and second image information is newly recorded. When attempting to perform so-called insert editing, in order to prevent servo operation disturbances and image disturbances during playback of the edited tape, tracking errors and tracking control of the rotating video head at the cut-in and cut-out points must be performed. Conditions such as the recording order of the pilot signals must be adjusted so as to maintain continuity with the tape pattern of the first image information.
Failure to do so will result in disturbances in the servo operation of the capstan servo system and disturbances in the reproduced image in the insert recorded portion during reproduction.

Conventionally, to solve this problem, CTL pulses (control pulses) were recorded along the running direction of the tape in correspondence with each track, and this pulse was recorded during playback.
In a VTR using a CTL tracking control method that uses CTL pulses to track a rotating video head, the CTL pulses are reproduced over the entire insert section and the first image information recording section before and after the insert section. While playing this
The capstan servo system is controlled by the CTL pulse to make the rotating video head track each track, and the timing at which the rotating video head passes the cut-in point and cut-out point of the insert section is detected by the reproduction CTL pulse. During this time, the rotating video head
A relatively simple method has been adopted in which the first image information is overwritten with the first image information.

However, in VTRs using the ATF tracking control method, information corresponding to CTL pulses is not originally recorded on the tape, so the CTL tracking control method cannot be applied as is, and original ideas have been attempted for some time. That is, the first method is to prepare a rotary erase head for erasing each track in the insert section at a position that rotates slightly ahead of the rotary video head, and this rotary erase head erases a portion of recorded information on each track. A method has been considered in which the second image information is written while partially reproducing the image and applying tracking servo to each track of the rotating video head based on a reproduction pilot signal included in the reproduction signal. In addition to the second rotating video head, a fixed head is provided that faces the cue tracks formed on the tape along its running direction, and when inserting the tape, this fixed head is used to control the pilot signal for each track. A method has been considered in which a corresponding cue signal is recorded in advance and the second image information is written while reproducing the cue signal.

However, in any of these conventional methods, a rotating erase head or a fixed head for cue signals is separately prepared, and a special electric circuit is required to operate this head in response to the timing when the rotating video head cuts in or out of the insert section. Therefore, the configuration of the editing device becomes complicated and expensive.

[Purpose of the invention]

In consideration of the above points, the present invention realizes recording of the second image information in the insert section and reliable tracking operation at the same time by using a rotating video head without providing such a special head or the like. It is something that you can get.

[Summary of the invention]

In order to achieve this purpose, the present invention includes:
During insert recording, the video head uses the first pilot signal of the already recorded first image information to record the second image information to be newly recorded, leaving a part of each track in the insert section. The video head is overwritten with the second pilot signal that changes continuously with respect to changes in frequency, and the first pilot signal reproduced from the above-mentioned partial area by the video head is used to overwrite the video head. is tracked by each track in the insert section.

〔Example〕

An embodiment in which the present invention is applied to an editing apparatus for an ATF type two-head helical scanning VTR will be described below in detail with reference to the drawings.

First, the operating principle of the ATF type tracking control device will be described with reference to FIGS. 1 to 3. That is, in this tracking control device, as shown in FIG. 1, a signal S1, which is a part of the playback output of a rotating video head as a playback head, is received by a pilot signal detection circuit 1 having a low-pass filter configuration, and is recorded on a magnetic tape as a recording medium. A reproduced pilot signal S2 having the reproduced output of the pilot signal as a component is generated, and this reproduced pilot signal S2 is supplied to the error signal forming circuit 3. The error signal forming circuit 3 sends out a tracking error signal S3 formed under the control of the lock point control circuit 4.

On the tape 5, as shown in FIG.
A set of four video tracks T1, _T2 , T3, and T4 on which f ₁ , f 2 , f ₃ , and f ₄ are recorded are formed diagonally and closely together so as to repeat in a cyclical manner.
The effective width of the video head constituting the playback head 6 is selected to be approximately equal to the width of the tracks T1 to T4, for example, so that the playback head 6 is currently scanning as shown by the solid line in FIG. When correctly tracking a track (this is referred to as a playback track), by reproducing only the pilot signal recorded on the track, only one type of pilot frequency component is included in the playback output. When the playback head 6 is shifted to the right or to the left with respect to the relevant track, as in the above example, the pilot signal recorded on the track adjacent to the right or left side of the relevant playback track is also reproduced and included in the playback output. There are two types of pilot frequency components, and the magnitude of each pilot frequency component is made to correspond to the opposing length of the reproducing head facing the corresponding track.

However, the frequencies of the four types of pilot signals f ₁ ~
_f4 is selected for the lower band of the color component converted to a low frequency (600 to 700 [kHz]), and for example, on the right side of the odd-numbered tracks T1 and T3 in the circulating four tracks T1 to T4. The frequency difference with the pilot signal of the left track is Δf _A , and the frequency difference with the pilot signal of the left track is Δf _B. The frequency difference between the truck and the pilot signal is Δf _B , and the frequency difference between the left truck and the pilot signal is Δf _A.

Therefore, head 6 is connected to odd-numbered tracks T1 and T.
3, if there is a signal component with a frequency difference of Δf _A as a frequency component of the pilot signal included in the reproduced signal, it can be seen that the head 6 is shifted to the right, and if there is a signal component with a frequency difference of Δf _B. If there is a component, it can be seen that the head 6 is shifted to the left, and if there is no signal component with a frequency difference of Δf _A and Δf _B , it can be seen that tracking is being performed correctly.

Similarly, head 6 is an even-numbered track T.
2. When reproducing T4, if there is a signal component with a frequency difference of Δf _B as a frequency component of the pilot signal included in the reproduced signal, it is known that the head 6 is shifted to the right, and if the frequency difference is Δf _A If there is a signal component of , it can be seen that the head 6 is shifted to the left.

In this embodiment, the frequencies f 1 , f 2 , f 3 , f 4 assigned to the first, second, third, and fourth tracks _T1 , _T2 , _T3 , and _T4 are f ₁ =102 [ kHz], _f2
= 116 [kHz], f ₃ = 160 [kHz], f ₄ = 146 [kHz], therefore, the difference frequencies Δf _A and Δf _B are Δf _A = |f ₁ −f ₂ |= |f ₃ −f ₄ |=14 [kHz] ...(1) Δf _B = |f ₂ −f ₃ |=|f ₁ −f ₄ |=44 [kHz] ...(2) is selected.

The reproduced signal S1 having the content obtained from the head 6 is given to a pilot signal detection circuit 1 having a low-pass filter configuration, and the reproduced signal is obtained by extracting the pilot signals of frequencies f ₁ to f ₄ contained in the reproduced signal S1. Pilot signal S2 is applied to multiplication circuit 14 as a first multiplication input. The reference pilot signal S11 of the lock point control circuit 4 is applied to the multiplication circuit 14 as a second multiplication input.

The lock point control circuit 4 includes a pilot signal generation circuit 16 that generates four types of pilot signals of frequencies _f1 to _f4 , and a head that scans the tape among two video heads in conjunction with a rotating drum (not shown). The switch circuit 17 receives a head switching pulse RF-SW (FIG. 3A) which changes the logic level each time the head switch is switched. In this embodiment, the switch circuit 17 has a quaternary counter circuit that performs a counting operation every time the level of the head switching pulse RF-SW changes. The corresponding gate signals are sequentially repeated, and the gates are opened by the gate signals of the tracks T1 to T4, respectively, and the pilot signals of frequencies _f1 to _f4 of the pilot signal generation circuit 16 are generated as shown in FIG. 3B. are sequentially transmitted as the reference pilot signal S11.

Note that the reference pilot signal S11 obtained at the output end of this switch circuit 17 is sent to the video head as a recording pilot signal via the signal line 18 during recording, so that the video head
While the fourth tracks T1 to T4 are being scanned, recording pilot signals of corresponding frequencies _f1 to _f4 are sequentially applied to the video head to record on each of the tracks T1 to T4.

In this way, while the head 6 scans the first to fourth tracks T1 to T4, the reproduced pilot signal S2 obtained at the output terminal of the pilot signal detection circuit 1 is generated in synchronization with the reproduced track. By multiplying the reference pilot signal S11 by the frequency component contained in the reproduced pilot signal S2 when there is a tracking error,
A multiplication output S12 is obtained which includes a signal component having a frequency different from the frequency of the reference pilot signal S11 (actually, the multiplication output S12 also includes other signal components such as the sum frequency component). This multiplication output S12 is given to first and second difference frequency detection circuits 20 and 21, each of which is constituted by a bandpass filter. First difference frequency detection circuit 20
When the multiplication output S12 includes a signal component with a difference frequency Δf _A based on the above-mentioned equation (1), this is extracted and converted into DC by the DC conversion circuit 22 having a rectifier circuit configuration, and the first DC level is An error detection signal S13 is obtained. Similarly, the second difference frequency detection circuit 21
When the multiplication output S12 includes a signal component of the difference frequency Δf _B based on the above equation (2), this is extracted and the second error detection signal S1 is output from the DC conversion circuit 23.
Get 4.

Here, when the head 6 is scanning the first, second, third and fourth tracks T1, T2, T3, T4 (therefore, the switch circuit 17 scans each track T1, T2 as shown in FIG. 3B). , T3, and T4), the reference pilot signals S11 with frequencies f ₁ , f ₂ , f ₃ , and f ₄ are sent out at timings corresponding to signals S1, T3, and T4. The reproduced pilot signal S2 has frequencies f ₁ and f 2 , f ₂ and f ₃ , f ₃ and f ₄ , f _{4 and} f ₁ as shown in FIG. 3 C1.
The difference frequencies Δf _A (=f ₁ - _{f 2} ), Δf _B (= f ₂ - f ₃ ), Δf _A (= f ₃ ~
_f4 ),
A signal sequentially containing Δf _B (=f ₄ to _{f 1} ) is generated. On the other hand, when the head 6 is shifted to the left, the reproduced pilot signal S2 sequentially changes frequencies f ₄ and f ₁ , f 1 and f ₂ , f ₂ and f ₃ , f ₃ and f , as shown in FIG. _3C2 . _Accordingly , the multiplication output S12 has a difference frequency Δf _B as shown in FIG. 3 D2.
(= _f4 ~ _f1 ), _ΔfA (= _f1 ~ _f2 ), _ΔfB (= _f2 ~ _f3 ),
Δf _A
(=f ₃ to f ₄ ) are sequentially included.

Thus, as shown in FIGS. 3E and F (for example, showing a right-shifted state), each time the head 6 switches tracks scanned, the DC level rises from 0.
And second error detection signals S13 and S14 can be obtained from the DC converting circuits 22 and 23.

First and second error detection signals S13 and S1
4 are given to the subtraction circuit 24 as an addition input and a subtraction input, respectively, thereby producing first and second error detection signals S13 and S1 as shown in FIG. 3G.
4 is obtained alternately, a subtraction output S15 that changes in an alternating current manner is obtained. This subtracted output S15 is applied to the first input terminal a1 of the direct changeover switch circuit 25, and its polarity is inverted in the inverting circuit 26 and applied to the second input terminal a2. The changeover switch circuit 25 switches the head 6, for example, to odd-numbered tracks T1 and T3 by the head changeover pulse RF-SW.
When scanning the first input terminal a1, the even numbered tracks T2 and T4 are switched to the first input terminal a1 side.
When the head 6 is being scanned, it is switched to the second input terminal a2, and thus, when the head 6 is shifted to the right as shown in FIG. (on the other hand, when there is a left shift state, the DC level output S16 has a magnitude corresponding to the left shift amount and becomes negative polarity), and this is the output amplification circuit 27 consisting of a DC amplifier.
It is sent out as a tocking error signal S3 via. Incidentally, if the head 6 is shifted to the right, for example, a signal component of the difference frequency Δf _{A appears at the output terminal of the multiplier circuit 14 when the reproduced track is an odd numbered track T1, T3, so that the signal component of the difference frequency Δf A} appears in the first difference frequency detection circuit 2.
The output from the 0 side is given to the subtraction circuit 24, and since the changeover switch circuit 25 is switched to the first input terminal a1 side at this time, it sends out an error signal S3 of a positive DC level. On the other hand, when the reproduction track is an even numbered track T2, T4, the multiplication circuit 14
Since the signal component of the difference frequency Δf _B appears at the output terminal of , the output from the second difference frequency detection circuit 21 side is given to the subtraction circuit 24, and at this time, the changeover switch circuit 25 is connected to the second input terminal a2. Since the polarity of the negative output of the subtraction circuit 24 is inverted by the inverting circuit 26, it is sent out as a positive DC level error signal S3.

Therefore, if this error signal S3 is used as a correction signal in the phase servo circuit of the capstan servo loop, and is corrected so that when it is positive, the tape running speed is made faster, and when it is negative, it is made slower, the video head and the playback track can be corrected. It is possible to correct the phase shift between the two and thus realize correct tracking servo.

Note that in the above-mentioned error signal forming circuit 3,
The signal components of the difference frequencies Δf _A and Δf _B are obtained from the pilot signals of the reproduced track and its adjacent tracks, and the error detection signals S13 and S14 are obtained based on these signal components.
The levels of the reproduced pilot signals _f1 to _f4 may be detected by respective reproduced pilot signal detection circuits having a bandpass filter configuration, and the error detection signals S13 and S14 may be obtained based on the detection outputs.

In the above principle configuration, the principle has been described assuming that when the head 6 correctly tracks each track, no difference frequency component is generated at the output terminal of the multiplication circuit 14. However, in reality, even in this tracking state, the reproduced signal S1 of the head is Pilot signals for adjacent tracks on the left and right sides are generated.

That is, in practice, if no guard band is provided between tracks during recording, newly recorded tracks are sequentially recorded so as to partially overlap already recorded adjacent tracks. Therefore, in this case, the width of the head 6 is larger than the width of each track T1 to T4, so that when tracking correctly, the head 6 protrudes into the adjacent tracks on the left and right sides. Therefore, since the head 6 reproduces the pilot signals of the tracks adjacent to the left and right sides, error detection signals S13 and S14 (Fig. 3E and F) is generated from the DC conversion circuits 22 and 23.

Furthermore, when a guard band is provided, the width of the head 6 becomes almost equal to the width of the track, but the pilot signals recorded on the adjacent tracks on the left and right sides are mixed into the reproduced signal of the head 6 as a crosstalk signal. do. Therefore, the error detection signal S1
3 and S14 include a signal component of a difference frequency corresponding to a crosstalk signal.

However, since the pilot signals mixed into the reproduced output S1 of the head 6 from the adjacent tracks are simultaneously generated as signal components of difference frequencies Δf _A and Δf _B at the output terminal of the multiplication circuit 14, the error detection signals S13 and S14 are When they are subtracted from each other in the subtraction circuit 24, they cancel each other out. Moreover, when the head 6 is tracking correctly, the head 6 is in a symmetrical position with respect to the tracks adjacent to the left and right sides.
The protrusion lengths of the left and right sides are almost equal, and the magnitude of the crosstalk is also almost the same for the left and right sides.In the end, the content of the subtraction output S15 is equivalent to the above case in which the width of the head 6 is considered to be almost equal to the width of the track, and Therefore, the tracking operation of the tracking control device is not adversely affected by signal components of different frequencies simultaneously arising from adjacent tracks on both sides due to the head width being larger than the track width or due to crosstalk.

The insert editing device according to the present invention has a tracking control section 30 and an insert control section 31, as shown in FIG.

The insert control unit 31 outputs an insert command signal S.
21 and a head switching pulse RF-SW to generate a reproduction/recording switching signal S22. That is, the insert control unit 31 receives the insert command signal S21.
The rotating video head 33A or 3
As shown in FIG. 5, 3B specifies the playback mode by maintaining the playback/recording switching signal S22 at, for example, a logic "H" level until the scanning of the track T4 immediately before the cut-in point P of the insert section W2 is completed. Then, the head 33A or 33B changes to the insert section W2 by the head switching pulse RF-SW.
When switching to the first track T1 and entering the cut-in point P, the reproduction/recording switching signal S22 is switched to the logic "L" level to designate the recording mode and to start the built-in timer. Eventually head 3
3A or 33B enters the start end R1 of the reproduction area R shown in the diagonal line in FIG. When 33A or 33B reaches the terminal end R2 of the reproduction area R, the reproduction/recording switching signal S22 is switched to the logic "L" level by the clock output of the timer to designate the recording mode.

The timer of this insert control section 31 is
When 3A or 33B is switched to the next track T2 by the head switching pulse RF-SW, it is cleared and the operation performed for the first track T1 is repeated. Similarly, the head 33A or 33B
are tracks T2, T3 of insert section W2...
Each time the insert controller 31 enters the playback area R during scanning, the insert control unit 31 switches the playback-record switching signal S22 to the logic "H" level to designate the playback mode.

The tracking control section 30 has the same configuration as that described above with reference to FIG. 1, except that a sample hold circuit 35 is inserted on the output side of the subtraction circuit 24. The sample and hold circuit 35 receives the subtraction output S15 of the subtraction circuit 24 at its input terminal, and has a switch 37 connected to its output terminal to which a hold capacitor 36 is connected. When this becomes the logic "H" level, it turns on and the voltage value of the subtracted output S15 is transferred to the capacitor 3.
6, and this hold voltage signal S23 is sent to the changeover switch circuit 25.

Furthermore, the playback/recording switching signal S22 of the insert control section 31 is given to the playback/recording circuit 38.
The reproducing/recording circuit 38 receives a head switching pulse RF-
It has a head changeover switch 39 that changes the signal path to the head 33A or 33B connected to the head terminals b1 and b2 by SW, and the common terminal d1 of the playback/record changeover switch 40 is connected to the non-head side terminal b3. has been done. The recording terminal d2 of the playback/recording changeover switch 40 receives a recording signal S2 formed by mixing the video signal S24 of the video circuit 41 with the recording pilot signal S25 sent from the switch circuit 17 to the recording signal line 18 in the mixing circuit 41.
6 through the recording amplifier circuit 43, and when the reproduction/recording switching signal S22 is at the "L" level, the common terminal d
A recording current is applied to the rotary video head 33A or 33B through the video head 1 and the ped selector switch 39. The playback terminal d3 of the playback/record changeover switch 40 is connected to a playback head amplifier circuit 44, which receives the video signal and pilot signal reproduced by the rotating video head 33A or 33B through the head changeover switch 39 to the common terminal d1. When the reproduction/recording switching signal S22 is at the "H" level, it is applied to the pilot signal detection circuit 1 through the reproduction head amplifier circuit 44.

In the above configuration, in the insert editing mode, the insert control section 31 first maintains the playback/recording switching signal S22 at "H" and switches the tracking control section 3.
0 sample hold circuit 35 is turned on, and the reproduction/recording switch 40 is switched to the reproduction terminal d3 side. At this time, head 33A or 3
3B scans the first image information recording section W1 before the insert section W2, reproduces the pilot signal together with the video signal from each track, and outputs this reproduction output S.
1 is applied to the pilot signal detection circuit 1 through the head changeover switch 39, the reproduction/recording changeover switch 40, and the reproduction head amplifier circuit 44. Therefore, as described above with reference to FIGS. 1 to 3, the subtraction output S15 of the error detection signals S13 and S14 is obtained at the output terminal of the subtraction circuit 24, and this is held in the capacitor 36 of the sample and hold circuit 35. The hold voltage signal S23 of this capacitor 36 changes in accordance with the subtracted output S15, thus
A tracking error signal S3 corresponding to the direction and amount of deviation from each track A and 33B is sent from the tracking control section 30.

In this way, the heads 33A and 33B track each track in the section W1, and thus the switch circuit 17 sends out a reference pilot signal S11 whose frequency changes in the order of f ₁ , f ₂ , f ₃ , f ₄ , while synchronizing with this. heads 33A and 33B so that
The reproduced output S1 from the pilot signal detecting circuit 1 includes a pilot signal whose frequency changes in that order, and this is obtained at the output terminal of the pilot signal detection circuit 1 as a reproduced pilot signal S2.

Eventually, when the heads 33A and 33B finish scanning the track T4 immediately before the cut-in point P (for example, the track T4 on which a pilot signal with a frequency of _f4 is recorded), and begin scanning the first track T1 of the insert section W2, Insert control section 31
receives the insert command signal S21, sets the playback/recording changeover signal S22 to "L", turns off the switch 37 of the sample hold circuit 35, and switches the playback/recording changeover switch 40 to the recording terminal d2.
switch to the side. At this time, a pilot signal having a frequency of _f1 was recorded on the track T1 together with the first image information, but the pilot signal with the frequency f1 was also recorded from the switch circuit 17 together with the second image information given from the video circuit 41 via the recording amplifier circuit 43. The frequency being f ₁
The recording pilot signal S25 is switched to the selector switch 40.
and 39 through rotating video head 33A or 3.
3B, it is overwritten on track 5.

This overwriting is performed while the tape 5 is running at a constant speed by a constant speed servo, but the first track T1 is
A state of almost tracking can be obtained.

In this way, while recording the second image information on the track T1, the head 33A or 33B is moved to the reproduction area R.
When reaching the position, the insert control section 31 sets the reproduction/recording switching signal S22 to "H", turns on the sample hold circuit 35, and switches the reproduction/recording switching switch 40 to the reproduction terminal d3 side. At this time, the head 33A or 33B reproduces the pilot signal (frequency is _f1 ) recorded together with the recording of the first image information in the reproduction area R, and this generates an error signal via the pilot signal detection circuit 1. It is given to the circuit 3 as a reproduction pilot signal S2. Therefore, the error signal forming circuit 3 sends out a tracking error signal S3 corresponding to the amount of deviation of the head 33A or 33B with respect to this first track T1, and thereby controls the capstan servo system to correctly position the head 33A or 33B. Truck T
1 to track. Thus head 33A
Or 33B is reproduced while scanning the reproduction area R.
Tracking is performed correctly on track T1 by ATF servo operation.

When the head 33A or 33B eventually leaves the reproduction area R, the insert control section 31 sets the reproduction/recording switching signal S22 to "L", turns off the sample hold circuit 35, and switches the reproduction/recording switching switch 40 to the recording terminal d2. switch to the side. At this time, the sample hold circuit 35 outputs the subtraction output S15 obtained in the subtraction circuit 24 for the reproduction area R.
is held in the capacitor 36. On the other hand, since the recording mode has been entered, the reproduction ATF servo for the capstan servo system is no longer performed, and the head 33A or 33B is again sent to the switch circuit 17 along with the second image information given from the video circuit 41 via the recording amplifier circuit 43. The recording pilot signal S25 having a frequency of _f1 is sent from the track T through the changeover switches 40 and 39.
Overwrite on top of 1.

Thus, when the head 33A or 33B has finished scanning the first track T1, it subsequently switches to the second track T2 and in the same way, the frequency f that was recorded by the head 33A or 33B together with the first image information is scanned. recording second image information together with a pilot signal having the same frequency as the _second pilot signal;
When entering the reproduction area R, the pilot signal of the first image information is reproduced and the reproduction ATF servo is applied to track the head 33A or 33B to the second track T2, and when exiting the reproduction area R, the second image information is reproduced again. is recorded together with the recording pilot signal S25 of frequency _f2 .

Thereafter, in the same manner, the second image information is overwritten on the third, fourth, . . . tracks T3, T4, . The reproduction ATF servo is applied by the pilot signal of the first image information recorded in R to cause the head 33A or 33B to track each track.

In this way, when the recording of the second image information for the last track T4 of the insert section W2 is completed, the insert command signal S21 that had been given to the insert control section 31 is no longer given, and the head 33
A or 33B switches to the cutout point Q of the next track T1. At this time, the insert control section 31
sets the playback-recording switching signal S22 to "H" and turns on the sample hold circuit 35, and
The reproducing/recording switch 40 is switched to the reproducing terminal d3 side, and thus the reproducing ATF servo is applied by the reproducing output S1 of the head 33A or 33B to cause the head 33A or 33B to track each track. Here, the pilot signal used by the head 33A or 33B to track the last track T4 of the insert section W2 and the pilot signal used to track the track T1 at the cutout point Q are both recorded together with the first image information. series (in other words, the frequency f _1
.about.f4 is continuously repeated), the change in the pilot signal at the cutout point Q has continuity.

Actually, the playback area R in the insert section W2
For example, the vertical blanking interval of 10H (approximately 600
[μsec]), the second image information can be reliably inserted into the insert section without dropping information that is effective as an image. If you do this, there is a risk that the vertical synchronization signal will be disturbed during playback, making it impossible to achieve vertical synchronization, but in this case, for example, inserting a pseudo vertical blanking signal created from the head switching pulse RF-SW into the playback output will correct this problem. The problem can be effectively avoided.

As described above, according to the configuration shown in FIG. 4, the scanning position of the head 33A or 33B in the insert section W2 is determined by applying the reproduction ATF servo using the pilot signal of the first image information. , the frequency change order of the pilot signal at cut-in point P and cut-out point Q has continuity, and the second image information to be newly recorded in the insert section is compared with the already recorded first image information. It is possible to reliably overwrite each track point.

Therefore, when playing back the tape that has been insert-edited in this manner as a whole, the head 33A or 33B can perform ATF tracking operation with good continuity at both the cut-in point P and the cut-out point Q.

Further, the sample hold circuit 35 is connected to the head 33A or 3 in each track of the insert section W2.
3B represents the tracking state of the relevant reproduction track when scanning the reproduction area R, and this represents the tracking state of the reproduction track when the reproduction area R is scanned, and this is the state in which the head 33A or 33 is used in the next track.
When B scans the reproduction region R, the result is that the value of the sample voltage signal S23 does not change suddenly. Therefore, the tracking error signal S3 also stably represents approximately the amount of deviation of the heads 33A and 33B from the relevant reproduction track, and thus tracking can be carried out smoothly.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to overwrite each track in the insert section using the pilot signal recorded together with the first image information while substantially applying the playback servo, and therefore the cut-in section in the insert section can be overwritten. It is possible to maintain the continuity of changes in the frequency of the pilot signal at point P and cutout point Q, and it is also possible to reliably track the second image information on the track formed when recording the first image information. .

[Brief explanation of drawings]

Fig. 1 is a block diagram showing the principle configuration of an ATF-based tracking control device, Fig. 2 is a schematic diagram showing a track pattern recorded on a tape, and Fig. 3 is a schematic diagram showing a track pattern recorded on a tape.
The figure is a signal waveform diagram showing the signals of each part in Figure 1.
The figure is a block diagram showing one embodiment of the insert editing device according to the present invention, and FIGS. 5 and 6 are schematic diagrams showing track patterns for explaining the operation thereof. 1...Pilot signal detection circuit, 3...Error signal forming circuit, 4...Lock point control circuit, 14...
...Multiplication circuit, 16...Pilot signal generation circuit,
17... Switch circuit, 20, 21... First and second difference frequency detection circuit, 22, 23... Direct current conversion circuit, 24... Subtraction circuit, 25... Switch circuit, 26... Inversion circuit , 30... Tracking control section, 31... Insert control section, 33A, 33
B... Rotating video head, 35... Sample hold circuit, 38... Playback-recording circuit, 39... Head changeover switch, 40... Playback-recording changeover switch, 41... Video circuit.

Claims (1)

[Scope of Claims] 1. A plurality of first pilot signals having different frequencies are cyclically changed and recorded together with first image information in a predetermined order for each track, and are read from each track by a recording/reproducing head. The recording/reproducing head is configured to track each of the tracks based on the reproduced first pilot signal, and the first image information is recorded on a track in a predetermined insert section among the tracks on which the first image information is recorded. In an insert editing device configured to insert-record the second image information at the same start and end timing as the image information track of the first image information track, the start and end timing of each track of the insert section is set by the recording/playback head during the insert recording. and the second image information, leaving a part of the middle region in the end section, is changed for each track of the insert section so as to have continuity with respect to the change in the frequency of the first pilot signal. The first pilot signal is overwritten with the second pilot signal, and the first pilot signal reproduced from the partial area by the recording/reproducing head is reproduced to cause the recording/reproducing head to write the first pilot signal on each track in the insert section. An insert editing device characterized by tracking. 2 Based on the first pilot signal reproduced from the partial area, a sample-hold circuit samples and holds a signal corresponding to the deviation of the recording/reproducing head from each track for each track. An insert editing device according to claim 1.