JPH0563841B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a video signal recording and reproducing device, and in particular, the present invention relates to a video signal recording and reproducing device, and in particular, a plurality of pilots having different frequencies are arranged on recording tracks formed in sequence across the running direction on a recording medium. The signal is recorded cyclically together with the video signal,
An automatic track following method (hereinafter referred to as an automatic track following method) uses a pilot signal regenerated by the reproducing head to cause the reproducing head to track each track.
This method is suitable for application to an image recording device (referred to as AATF method).

[Background technology and its problems]

Generally, in an image recording device such as a video tape recorder (VTR), when editing a plurality of image information each having a video signal so as to successively concatenate them onto a single tape, recording and pausing operations are repeated as necessary. Each piece of recorded information is transferred without any gaps during operation, but the various conditions such as the timing of recording new image information and the recording order of head tracking control signals at the joints are the same as when recording continuously. Failure to do so will result in disturbances in the servo operation of the cabstan servo system and disturbances in the reproduced image at the joints of recorded information during reproduction.

Conventionally, to solve this problem, CTL pulses (control pulses) were recorded along the running direction of the tape, corresponding to each track, and this pulse was recorded during playback.
In an editing device using the CTL tracking control method, which uses CTL pulses to track the head, the first information is recorded and the editing device is temporarily stopped, and then the editing device is temporarily stopped.
Rewind the tape while counting the CTL pulses, then put the device in playback mode, count the CTL pulses by the amount of rewinding the first contact information, apply the playback CTL servo, playback, and during this time, The phase of the scanning trajectory of the head is adjusted to each track of the recorded first information, and when the head reaches a track of a predetermined number of fields at the end of the track just before returning to the pause position, the device is put into recording mode. By overwriting new second information on the track of the field at the end of the lever, the first information is recorded while being erased.

In practice, for example, after rewinding the tape by 15 fields, the reproducing servo is applied to 13 fields, and recording of the second information is started overlapping the first information of the remaining two fields. If the level of the recording current for the second information is increased by several [dB] during normal recording for several seconds after switching to the recording mode, it is possible to prevent the adverse effects of the unerased overwriting from occurring.

In this way, in an editing device using the CTL tracking control method, by counting CTL pulses, the recording track of the first information recorded at the switching point of each mode of tape rewinding, playback, and recording can be detected. Therefore, it is possible to prevent servo disturbances and reproduction image disturbances at the joint between the first and second recorded information.

However, in an editing device using the ATF tracking control method, since CTL pulses are not recorded on the tape, it is not possible to easily know the actual tape rewind length, playback or recording length, and therefore the first If the timing to switch to the recording mode fails when entering the playback mode after rewinding a predetermined field of information, both the first and second information will not be recorded at the seam even if the rewinding length has passed. A blank area was created, which could cause the image of the seam to be distorted. Furthermore, the order in which the frequencies of the pilot signals that are recorded on each track of the first information that has already been recorded is not continuous with the order in which the frequencies of the pilot signals that are newly recorded in the second information are changed are not continuous. Therefore, there was a risk that the tracking servo operation would be disturbed at the seam.

[Purpose of the invention]

In consideration of the above points, the present invention utilizes the pilot signal recorded in each track of the first information to connect the first and second information without creating a blank space at the joint, and also by adjusting the frequency of the pilot signal. The present invention attempts to propose a video signal recording and reproducing apparatus that can capture second information following first information without disturbing the change order.

[Summary of the invention]

In order to achieve this purpose, the present invention includes:
1 of the last track where recording of the video signal ends
A pilot signal having the same frequency as the pilot signal recorded on the previous track is recorded on the track following the last track. In addition to this, the recording level of the pilot signal recorded on the track immediately before the last track and/or the pilot signal recorded on the track next to the last track can be compared to the recording level of the pilot signal of the other tracks. raise it above the level.

〔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 part of the signal S1 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. Create a reproduced pilot signal S2 whose component is the reproduced output of the pilot signal,
This reproduced pilot signal S2 is given 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 together with image information, are formed closely diagonally so as to repeat in a circular manner. There is. 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 for playback as shown in FIG. When a track (this is referred to as a playback track) is correctly tracked, only one type of pilot frequency component is included in the playback output by playing back only the pilot signal recorded on the track. 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 ~
f ₄ is selected for the lower band of the color component converted to a low frequency (600 to 700 [kHz]), and is located on the right side of the circulating four tracks T1 to T4, for example, centered on the odd-numbered tracks T1 and T3. 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 corresponds to odd-numbered tracks T1 and T3.
When reproducing a pilot signal included in the reproduced signal, if there is a signal component with a frequency difference of Δf _A , 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, 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 T2,
When reproducing T4, the frequency difference Δf _B is the frequency component of the pilot signal included in the reproduced signal.
If there is a signal component of , it is known that the head 6 is shifted to the right, and if there is a signal component with a frequency difference of Δf _A , it is found 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], f ₂ = 116
[kHz], f ₃ = 160 [kHz], f ₄ = 146 [kHz], and 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 ₄ −f ₁ ｜=44 [kHz]
...(2) has been selected.

The reproduced signal S1 having such content obtained from the head 6 is given to a pilot signal detection circuit 1 having a low-pass filter configuration, and a reproduced pilot signal S2 obtained by extracting the pilot signal contained in the reproduced signal S1 is sent to a multiplication circuit 14. It is given as the 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 is connected to a pilot signal generation circuit 16 that generates four pilot frequency outputs of frequencies f ₁ to _{f 4} and a rotating drum (not shown) that scans the tape of two video heads. The switch circuit 17 receives a head conversion pulse RF-SW (FIG. 3A) which changes the logic level each time the head 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 tracks T1 to T4, respectively, and the pilot frequencies _f1 to _f4 of the pilot signal generation circuit 16 are outputted 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 connected to signal line 1 during recording.
8 to the video head as a recording pilot signal, thus causing the video head to record the first to fourth recording pilot signals.
While scanning the tracks T1-T4, pilot signals of corresponding frequencies _f1 - _f4 are sequentially applied to the video heads to record on the respective tracks T1-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 reference pilot signal S11, a multiplication output containing a signal component having a frequency difference between the frequency component included in the reproduced pilot signal S2 when there is a tracking error and the frequency of the reference pilot signal S11 is obtained. S12 (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 comprised of a bandpass filter. The first difference frequency detection circuit 20 outputs a multiplication signal.
When S12 contains a signal component with a difference frequency Δf _A based on the above equation (1), this is extracted and converted to DC by the DC conversion circuit 22 having a rectifier circuit configuration, and the first error detection of the DC level is performed. Obtain signal S13. Similarly, the second difference frequency detection circuit 21 outputs the multiplication signal S12.
contains a signal component with a difference frequency Δf _B based on the above equation (2), this is extracted and the DC conversion circuit 23
A second error detection signal S14 is obtained from the second error detection signal S14.

Here, when the head 6 is trying to track the first, second, third and fourth tracking T1, T2, T3, T4 (therefore, the switch circuit 17
As shown in Figure 3B, each track T1, T2, T3,
At the timing corresponding to T4, the frequencies are f ₁ , f ₂ , f ₃ ,
If it is shifted to the right (the reference pilot signal S11 of head ₆ is being transmitted), the reproduced pilot signal S2 obtained based on the reproduced signal S1 of the head 6 will be
As shown in C1, the frequencies f ₁ and f ₂ , f ₂ and f ₃ , f ₃ and
The pilot signals of f ₄ , f ₄ and f ₁ are included, and the difference frequencies Δf _A (=f ₁ to f ₂ ) and Δf _B (=f ₂ to f ₃ ), Δf _A
(=f ₃ to _{f 4} ) and Δf _B (=f ₄ to f ₁ ) are 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 includes the difference frequencies Δf _B (=f ₄ to _{f 1} ), Δf _A (=f ₁ to f ₂ ), and Δf as shown in FIG. ₃ D2. _B (=f ₂ ~
_f3 ),
Δf _A (=f ₃ to f ₄ ) is 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.

The first and second error detection signals S13 and S14 are supplied to the subtraction circuit 24 as an addition input and a subtraction input, respectively, so that the first and second error detection signals S13 and S14 are alternately output as shown in FIG. 3G. Subtraction output S15 that changes AC each time it is obtained
is obtained. This subtraction 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. For example, when the head 6 is scanning the odd-numbered tracks T1 and T3, the changeover switch circuit 25 is switched to the first input terminal a1 side by the head switching pulse RF-SW; When scanning T2 and T4, a switching operation is performed to the second input terminal a2, and thus a positive DC level corresponding to the amount of rightward deviation when the head 6 is in the rightward deviation state as shown in FIG. output
S16 is obtained (on the other hand, when the left shift state occurs, the DC level output S16 has a magnitude corresponding to the left shift amount and becomes negative polarity), and this is outputted via the output amplification circuit 27 consisting of a DC amplifier. It is sent out as a king error signal S3. 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 or T3, so that the signal component of the difference frequency Δf A} appears on the first difference frequency detection circuit 20 side. The output from subtraction circuit 2
4, and since the changeover switch circuit 25 is switched to the first input terminal a1 side at this time, a tracking error signal S3 of a positive DC level is generated.
Send out. On the other hand, when the reproduced tracks are even-numbered T2 and T4, a signal component of the difference frequency Δf _B appears at the output terminal of the multiplication circuit 14, so that the output from the second difference frequency detection circuit 21 side is
4, and since the changeover switch circuit 25 is switched to the second input terminal a2 at this time, the negative output of the subtraction circuit 24 is polar-positive inverted by the inversion circuit 26 to track the positive DC level. Send as error signal S3.

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

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 multiplier circuit 14, but 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 in the recording mode 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 S13
and S14 include a signal component of a difference frequency corresponding to a crosstalk signal.

However, since the pilot signals mixed into the reproduction output S1 of the head 6 from the adjacent tracks are simultaneously generated at the output terminal of the multiplication circuit 14 as signal components with difference frequencies Δf _A and Δf _B , 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. Furthermore, when the head 6 is tracking correctly, the head 6 is in a symmetrical position with respect to the adjacent tracks on the left and right sides, so the length of the protrusion of the head 6 is almost equal between the left and right sides, and the magnitude of crosstalk is almost the same. The left and right sides are equal, so the subtracted output S15
The content of is equivalent to the above case in which the width of the head 6 is considered to be approximately equal to the width of the track. Therefore, in the tracking operation of the tracking control device, the width of the head 6 is larger than the width of the track, or due to crosstalk, the adjacent There is no deleterious effect of signal components of difference frequencies arising simultaneously from both tracks.

Note that in the above-mentioned error signal forming circuit 3,
The signal components of the difference frequencies Δf _A and Δf _B between the pilot signals of the reproduced track and its adjacent tracks are obtained, and the error detection signals S13 and Δf B are generated based on these signal components.
S14 was obtained, but instead of this, the frequency f ₁ ~
The level of the reproduced pilot signal _f4 may be detected by a reproduced pilot signal detection circuit having a bandpass filter configuration, respectively, and the error detection signals S13 and S14 may be obtained based on the detection outputs.

As shown in FIG. 4, the video signal recording apparatus according to the present invention includes a tracking control unit 30, a joint track determination unit 31, and a recording level switching unit 32.

The tracking control device section 30 has the same configuration as that in FIG. 1, as shown by assigning the same reference numerals to corresponding parts to those in FIG. 1.

On the other hand, the joint track determination section 31 has a Schmitt circuit 35 consisting of an operational amplifier operating with hysteresis, and the tracking error signal S3 obtained at the output terminal of the output amplification circuit 27 of the tracking control device section 30 is applied to its non-inverting input terminal. When this voltage drops to a voltage level lower than the Schmitt voltage V _R of the reference power supply 36 applied to the inverting input terminal, a flip-flop circuit 37 is set to receive the vertical blanking signal VD as a reset signal by the output of the Schmitt circuit 35. , a joint track discrimination signal S21 of logic "H" is sent out from its output terminal as a recording mode switching command signal. The Schmitt circuit 35 is provided with a continuous shooting flag signal S22 which is generated when the "pause" button is operated on the operation panel as an operation permission signal.
is given.

The recording level switching section 32 also includes series resistors 41 and 4 connected to the pilot signal recording line 18 derived from the switch circuit 17 as shown in FIG.
The output of the attenuation circuit 43 consisting of two attenuation circuits 43 is sent to the video head as a recording signal S23 along with a color signal SC and a luminance signal SY via a reproduction amplification circuit 44. A short circuit switch circuit 45 is connected in parallel to one resistor 42 of the attenuation circuit 43, and as shown in FIG. Tracks 46B and 46 before and after the track 46 of
When scanning A, the on control signal S24 is applied from the switch circuit 17, and the shorting switch circuit 45 is turned on, so that the recording level of the pilot signal recorded on the last track 46 is lowered, for example, by +.
It is designed to further increase the level by about 6 [dB].

Here, the last track 46 when recording the first image signal is a predetermined track, for example, a fourth track.
T4 is predetermined, and the switch circuit 17 during the continuous shooting operation sends out the ON control signal S24 at the timing when the head 6 operates the fourth track T4.

In the recording mode, the switch circuit 17 is connected to the first to fourth switches as described above with respect to FIGS. 1 to 3.
Frequency f ₁ to _{f 4} at the timing of tracks T1 to T4
The pilot signal S25 of
At the timing of the next track 46A, a pilot signal with the same frequency _f3 as the pilot signal recorded on the previous track 46B (in normal recording mode
f ₄ is followed by f ₁ , but this order is changed). The order of frequency changes is changed by changing the output of a counter built into the switch circuit 17 on the condition that the continuous shooting flag signal S22 is used.

The tape is controlled by a running control circuit 47 shown in FIG. That is, the capstan motor 48
A frequency generator 49 detects the rotation of the drive signal S26, and a drive output S26 corresponding to the frequency output S25 is applied from a speed control circuit 50 to a drive amplifier circuit 52 via an addition circuit 51. Frequency output of frequency generator 49
S25 is applied to the phase comparator circuit 54 through the 1/N frequency divider circuit 53, and a phase deviation output S27 from the vertical blanking signal VD is obtained. It is applied to the adder circuit 51 through the recording side terminal b1.

The playback side terminal b2 of this recording-playback switching circuit 56
is given the tracking error signal S3 of the tracking control section 30, and when it becomes logic "H" due to the joint track discrimination signal S21 of the joint track discrimination section 31, it is switched to the recording side terminal b1.

In the above configuration, in the recording mode, the video head 6 cyclically records the first, second, and
Third and fourth tracks T1, T2, T3, and T4 are formed and recorded on the tape, and in synchronization with this, the frequencies are cyclically transmitted from the switch circuit 17 in the order of f ₁ , f ₂ , f ₃ , and f ₄ . A changing recording pilot signal S25 is sent to the video head 6 through the recording signal line 18 and is transmitted along with the video signal to the corresponding tracks T1, T2,
Recorded in T3 and T4 respectively.

However, when the "pause" button is operated on a separate operation panel, a continuous shooting flag signal S22 is generated, and the recording current for the video head 6 is changed to the next track 46A after the last track 46.
is maintained until the scan is completed. In this way, the switch circuit 17 records the pilot signal of frequency _f4 at the timing of the last track 46, and then
The frequency change order is changed at the timing of the next track 46A, and a pilot signal having the same frequency as the frequency _f3 of the pilot signal on the track 46B immediately before the track 46 is recorded.

By the way, at the timing when the head 6 scans the tracks 46B and 46A adjacent to the left and right sides of the track 46, the short circuit switch circuit 45 of the attenuation circuit 43 is turned on, so that the recording level of the pilot No. S23 is increased by a predetermined amount. Become.

Thereafter, the tape is rewound by a predetermined field in rewind mode, and in this state the apparatus enters pause mode. Here, the amount of tape rewinding can be arbitrarily selected, for example, from 3 to 10 tracks, depending on the need, and the key is to make sure that the amount of tape rewinding is sufficient to apply servo to the tracking servo system during the subsequent playback mode. It would be better if it could be rewound by the number of tracks.

This pause mode is canceled when a "record" button is operated on a separate operation panel, and the mode becomes playback mode.

In this way, when the playback mode is entered, the tracking error signal S3 of the tracking control unit 30 is applied to the tracking servo system through the recording-playback switching circuit 56 to cause the video head 6 to track each track, and this tracking error signal S3 is given to the seam determining section 31.
The seam determination unit 31 receives a seam photographing flag signal S22.
is given as an operation permission signal to the simulation circuit 35, and therefore monitors whether or not there is a fluctuation in the level of the tracking error signal S3 in the reproduction mode.

At this time, the tracking control unit 30 generates a signal of the difference frequency between the frequency component of the pilot signal S2 reproduced by the video head 6 and the frequency component of the reference pilot signal S11 in the same manner as described above with reference to FIGS. 1 to 3. Tracking is applied to the tracking servo system by sending out a tracking error signal S3 depending on the presence or absence of the component and its magnitude. Then, when tracking is applied, the control device section 3
The output S16 of the 0 changeover switch circuit 25 and therefore the tracking error signal S3 are maintained at the 0 level. In this state, crosstalk signals based on the pilot signals of the tracks on both sides mix into the reproduced pilot signal S2, but the difference frequencies between them and the reference pilot signal S11 are Δf _A and Δf _B , and the magnitudes are almost equal, so Also in the subtraction circuit 24, when the error detection signals S13 and S14 are subtracted, they cancel each other out and do not appear in the subtraction output S15.

In this state, the joint track discrimination circuit 31 determines that the video head 6 has not yet reached the last track 46 of the tape 5, and the joint track discrimination signal S21 is maintained at the logic "L" level. Since the recording mode switching command signal has not been sent, the video head 6 continues playing.

However, when the head 6 starts scanning the starting end 58 of the last track 46 (the fourth track T4 in the case of FIG. 6), the head 6 starts scanning the starting end 58 of the last track 46 (the fourth track T4 in the case of FIG.
Get into the correct tracking position for 6. At this time, a pilot signal of frequency _f3 is mixed as crosstalk from track 46B on the left side of the track 46, and a pilot signal of the same frequency _f3 is mixed as crosstalk from track 46A recorded on the right side area. Therefore head 6
The reproduced output S1 contains a pilot signal component whose frequency difference from the frequency _f4 of the reference pilot signal S11 is _ΔfA , and this is caused by the subtraction circuit 24 and the switching as in the case of left shift during normal tracking operation. A negative tracking error signal S3 is sent from the output amplifier circuit 27 via the switch circuit 25 (the third
Figures B, C2, D2).

Incidentally, if the head 6 is correctly tracking the fourth track T4, which records a pilot signal of frequency _f4 , as in a normal track pattern, it is caused by the pilot signal mixed in from the track T3 on the left side. The signal component of the difference frequency Δf _A is canceled in the subtraction circuit 24 by the signal component of the difference frequency Δf _B generated by the pilot signal mixed in from the right track T1.
Therefore, the signal level of the tracking error signal S3 becomes 0 level. On the other hand, when the head 6 tracks the last track 46 in the continuous shooting mode, the signal level of the signal component between the pilot signal mixed in from the left track and the reference pilot signal is mixed in from the right track. A signal component having a level obtained by adding the signal levels of the signal components between the pilot signal and the reference pilot signal is obtained at the output end of the subtracting circuit 24 as a signal component of the difference frequency Δf _A. Incidentally, in the case of Figure 6, the result is that the crosstalk from adjacent tracks does not cancel each other out, but rather adds up, and therefore the tracking error signal suddenly rises from 0 level to quite a high level when the head tracks the last track. It will rise to the level.

In addition, when entering the continuous shooting mode, the recording level of the pilot signal recorded on the tracks 46B and 46A adjacent to the left and right of the last track 46 is set higher than the normal recording level by the attenuation circuit 43. Since it is recorded at the level,
The amount of variation in the level of the tracking error signal S3 when the track 46 is tracked can be sufficiently increased as required.

In this way, the level of the tracking error signal S3 rises significantly from the 0 level and exceeds the reference voltage V _R of the seam track discrimination circuit 31, and thus the level of the seam track discrimination output S21 changes from logic "L" to logic "H". This change is sent out as a recording mode switching command signal.

At this time, the apparatus switches to the recording mode when the head 6 finishes scanning the track T4 and reaches the end 59. Thus, head 6 is the next track 46.
When switching to A, switch circuit 1 is applied to this track.
The recording of the first field of the second information is started with the pilot signal S23 of frequency _f1 sent from 7 through the recording signal line 18.

Therefore, according to the configuration shown in FIG. 4, the second information is recorded so that the pilot signal changes continuously so that it is adjacent to the last track 46 where the first information that has already been recorded is recorded. Thus, it is not necessary to overwrite the first information with the second information as in the conventional case, so the first information is not sacrificed, and the information is recorded at the joint. This allows continuous shooting without the risk of creating blank tracks.

Incidentally, in the above embodiment, the time constant of the loop characteristic of the servo system including the capstan motor etc. is such that when the last track 46 is scanned, the tracking error signal S3 reaches a level corresponding to the leftward deviation state. If the size is selected so that even if the tape changes, the mechanical inertia of the capstan motor and capstan wheel will allow the tape to travel at approximately the same speed, head 6 will be able to move to the last track. 46 can be scanned with almost tracking.

In the above-mentioned embodiment, a case was described in which the last track 46 for continuous shooting was selected as the fourth track T4, but instead of this, the first, second, and third tracks T1, T2 , T3 may be selected.The key is to record a pilot signal of the same frequency as the frequency of the pilot signal recorded on the previous track 46B on the next track 46A after the last track 46. Just do it.

In addition, in the above example, the width of the head is set to track T1.
~The width of T4 should be approximately equal to the width of track 46A, 4 on both adjacent sides when tracking correctly.
Crosstalk from 6B was detected using a pilot signal to detect the last track 46, but instead, the width of the head was made larger than the track width and the left and right ends of the head were used to detect the crosstalk on both sides 46A, 46.
Even if the B pilot signal is directly reproduced, the same effect as in the above case can be obtained.

Furthermore, in the embodiment described above, the tracks 46A, 46 adjacent to both sides of the last track 46 are
The recording level of both pilot signals of track B is set high, but instead of this, tracks 46A and 46B adjacent to both sides of the last track 46 are set to high.
The recording level of one of the pilot signals may be set high.

Furthermore, in the above description, the tracking control unit 30 is used as an input to the seam track discrimination circuit 30.
The tracking error signal S3 obtained at the output terminal of the error signal forming circuit 3 was used, but instead of this,
A signal forming circuit dedicated to the seam tracking discrimination circuit having the same configuration as this error signal forming circuit 3 is provided, and a tracking error signal is sent from this dedicated signal forming circuit.
It is also possible to obtain a signal corresponding to S3 and use this signal to determine the joint track.

Further, in the above description, rewinding is performed for a predetermined field, but instead of this, rewinding may be performed for a predetermined period of time.

Furthermore, in the case of the embodiment shown in FIG.
Tracking error signal obtained at the output end of 7
S3 is used to determine the joint track, but instead of this, the output of the changeover switch circuit 25 may be used as shown by the dotted line 35. In other words, the head 6 determines the last track T4. The signal to the seam determining section 31 may be extracted from a position where an output responsive to the tracking error signal S3 can be detected with a sufficiently short time constant during scanning.

〔Effect of the invention〕

As described above, according to the present invention, the pilot signal recorded on the track together with the first information is used to transfer the second information to the track following the last track where the first information is recorded. It is possible to obtain a splicing editing device that does not need to be recorded over the information of the track and that does not cause the possibility of producing blank tracks that are not recorded. Accordingly, in particular, according to the present invention, a pilot signal having the same frequency as the pilot frequency of the previous track 46B is recorded on the next track 46A of the last track 46 of the first image information, and then rewound. Therefore, it is possible to obtain a joint track discrimination signal S21 that clearly responds when the head 6 reaches the last track 46 while reproducing the first information. In addition to this, according to the present invention, the tracks 46A and 4 adjacent to both sides of the last track 46
Since the pilot signal is recorded on track 6B at a higher recording level than other tracks, the tracking error signal has a more noticeable level fluctuation.
S3 is obtained, and thereby the joint track discrimination signal S21 can be obtained more reliably and easily.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing the principle configuration of an ATF type 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.
FIG. 5 is a block diagram showing an example of a video signal recording and reproducing device according to the present invention, FIG. 5 is a connection diagram showing the detailed configuration of the recording level switching section, and FIG. 6 is a schematic diagram showing the track pattern recorded on the tape. 7 are block diagrams showing the scan control circuit. 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 converting circuit, 24... subtracting circuit, 25... changeover switch circuit, 26... inverting circuit, 30... Tracking control device section, 31... Seam track discrimination circuit,
32... Recording level switching unit, 35... Schmitt circuit, 37... Memory circuit, 43... Attenuation circuit, 4
5...Short-circuit switch circuit, 47...Travel control circuit.

Claims (1)

[Scope of Claims] 1. A video signal in which a plurality of pilot signals with different frequencies are recorded along with a video signal while being changed periodically for each track, and tracking control is performed based on the plurality of pilot signals with different frequencies during playback. In a recording/reproducing device, in response to a stop signal instructing to stop recording a video signal, a pilot signal having the same frequency as the pilot signal recorded on the track immediately before the last track on which the recording of the video signal ends is transmitted. A video signal recording and reproducing apparatus characterized in that the recording is stopped after recording on the track following the last track. 2. In a video signal recording and reproducing device that records a plurality of pilot signals with different frequencies together with a video signal while changing them periodically for each track, and performs tracking control based on the plurality of pilot signals with different frequencies during playback, In response to a stop signal that instructs to stop recording the signal, a pilot signal with the same frequency as the pilot signal recorded on the track immediately before the last track where recording of the video signal ends is sent to the next track after the last track. After recording on the last track, the recording is stopped, and the recording level of the pilot signal to be recorded on the track immediately before the last track and/or the pilot signal to be recorded on the next track after the last track is set. A video signal recording and reproducing device characterized in that the recording level of pilot signals of other tracks is higher than that of other tracks.