JPS6350949A - Magnetic tape running controller - Google Patents

Abstract

PURPOSE:To perform one field/one track intermittent running, by providing a brake counter which counts a capstan FG pulse by the number of tracking from a dummy control signal, and generates a brake timing. CONSTITUTION:A dummy CTL counter (c) counts the capstan FG pulse from a control signal CTL reproduced in intermittent running, and generates a dummy CTL. And a tracking counter (s) counts the number of clocks during a period when the number of tracking are decided, for example, the period when an analog monostable multivibrator is turned on, and stores the number until one intermittent running is completed as the number of tracking. In a field where the CTL is reproduced, a brake counter (y) counts the FG from the dummy CTL generated at the counter (c) in one preceding intermittent running, and generates the brake timing at a time when a counted number arrives at the number of tracking, then, the one track/one field intermittent running is realized.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a video tape recorder (
The present invention relates to a magnetic tape running control device for a VTR (hereinafter abbreviated as VTR).

2. Description of the Related Art VTRs that produce slow-motion images by intermittently running two tracks of magnetic tape are already commercially available. The tape running control technology will be explained using a commercially available VTR as an example.

FIG. 9 is a schematic diagram of the recording format of a commercially available VTR. 101 is an audio track, and 104 is a video track, in which one field of video signals is recorded on one recording track by an L head and an R head having different azimuth angles. Also, T16 page is the time of 1/3o second of one frame of the video signal, and T2 is 1
Represents the field time 1/6o second. 105 is a control signal for tape running control (hereinafter referred to as CTL)
Then, once every two tracks of the tape, that is, T
1 is recorded once. 103 represents the running direction of the tape, and 1o2 represents the recording direction of the head. Commercially available VTRs use tapes with this recording format as CTL10.
5 as a reference for running, two tracks, that is, one frame of the video signal, are run intermittently to obtain a slow motion image. This magnetic tape running control device will be explained using FIG. 10 and FIG. 11.

At the timing tl in FIG. 10, the capstan start command signal a is transmitted to the capstan control device 11 in FIG.
8, the capstan control device 118 causes the capstan drive device 120 to set the capstan current limit command signal amount to High (hereinafter abbreviated as H) and the capstan direction command signal q to Low. (Hereinafter, L
It is abbreviated as. ). The capstan current limit command signal f is a signal that regulates the upper limit of the capstan drive current, and is an HSMiddle (hereinafter abbreviated as M), L signal. The capstan direction command signal q is H, M, and L signals, and when it is H, it is in the reverse direction, and when it is
When it is, it is a stop command, and when it is L, it is a forward direction command. Therefore, at this timing, the current shown in Figure 10 flows through the capstan motor 112 and it starts rotating, and the tape starts running in the direction of arrow 3 shown in Figure 9.

When running starts, the control signal 105 shown in FIG. 9 is reproduced at timing t2 in FIG.
Through the amplifier 111 and waveform shaping circuit 112 in the figure, it is inputted to the capstan control device 118 as a CTL pulse b. At this time, the capstan control device 118
outputs a trigger pulse d to a delay circuit 119 whose delay time can be varied from the outside, the delay circuit 119 starts charging, and its output e is input to the capstan control device 118.

At timing t3 in FIG. 10, when the capstan 7A-ge control device 118 detects the discharge start edge of the delay circuit 119, it outputs the capstan direction command signal q to H1, that is, a reverse direction command, and starts the capstan drive. Device 120 applies current in a direction that causes capstan motor 122 to stop. This timing is called brake timing.

Next, when the brake timing is entered, the capstan motor 122 is decelerated and stopped.

Next, as a method for detecting that the capstan motor 122 has stopped, a two-phase FG reversal detection method will be described as an example.

121 in Fig. 11 is a two-phase FG generator, which has a phase of 9
Generates 0 degree FG pulses and i, and when the tape advances in the forward direction shown by arrow 1o3 in Figure 9, h is generated, and when the tape travels in the opposite direction, i is generated, each with a 90 degree phase advance. Configure it like this. Reference numerals 113 and 115 are amplifiers for amplifying i into the FG pulse, and reference numerals 114 and 116 are waveform shaping circuits. Reference numeral 117 is a capstan direction detection circuit which outputs L when the tape advances in the forward direction shown by arrow 3 in FIG. 9 and H when it advances in the reverse direction since the phases of k and i differ by 90 degrees. , C is its output signal.

With this configuration, the first
The capstan control device 118 in FIG. 1 detects the timing at which the output of the capstan direction detection circuit 117 changes from L to H, that is, the timing at which the capstan motor 122 starts rotating from the forward direction to the reverse direction, and determines the capstan direction. Command signal q to L, capstan current limit command signal f
Set to L to stop the capstan. At this time, the capstan direction command signal q is the L1 forward direction command, but the capstan current limit command signal f is L, so no capstan current flows and the capstan stops. (In addition, the first
The period from tl to t2 in Figure 0 is the acceleration period, the period from t2 to t3 is the constant speed period, the period from t3 to t4 is the braking period, the period from tl to t4 is collectively referred to as the transition period, and from t4 to tl, that is, during intermittent driving. is hereinafter referred to as the suspension period. ) During the constant speed period, the time from when the CTL pulse is reproduced to the brake timing can be varied by the delay time of the delay circuit 119 shown in FIG. This is the tracking amount that determines at which position field still playback is performed. The reason for making the tracking amount variable is the ninth
10. When playing back a tape on which the CTLs shown in the figure are recorded with their positions shifted, or when the relative positions of the video track and CTL are shifted due to the mechanical temperature characteristics of the playback head of the CTL, etc. CT at timing t2 in the figure
Even if the brake period starts at a fixed time after L is reproduced, a noiseless still image is not necessarily obtained during the stop period. Therefore, the volume of the delay circuit 119 in FIG. 11 is generally a user volume. The maximum variable range of this volume is from the time when the tape speed reaches a speed sufficient to reproduce the CTL shown at 6 in Fig. 9 to the brake timing, as shown in Fig. 12 A, and the minimum This is the case where the CTL is regenerated just before the brake timing, as shown at the beginning of FIG. In both cases, the CTL is set as the standard for intermittent running by 10A, so the CTL must be within a range that can be regenerated before the brake timing during two-track intermittent running.

This range is called the tracking range.

By the above method, the tape is intermittently run by repeatedly stopping, shifting, and stopping the capstan motor 112 shown in FIG. 11, and during the stop period, the recording track by the L head 4 shown in FIG. 9 is repeatedly played back. to obtain a field methyl image, and during the transition period, the recording track by the R head is
A field still image is obtained by reproducing the recorded track by the L head repeatedly during a stop period after 60 seconds of reproduction, and a slow motion image is realized.

Problems to be Solved by the Invention In the conventional method of obtaining a slow motion image by intermittently running one frame of two tracks based on this precise CTL, the movement is rough, and the R head is played for 1/60 seconds during the transition period. The recorded track cannot be displayed as a still image.

In the present invention, after a field still image is obtained on a recording track by an L head, the tape is intermittently run from one track to another, and the field still image is repeatedly reproduced on the next recording track by an R head. This makes it possible to realize a smooth slow motion, that is, a throw that reproduces both fields. In order to realize this slow reproduction of both fields, a tape running control technique that allows the tape to run intermittently on one track is essential. However, in a commercially available VTR, the CTL is recorded only once every two tracks, and when one track is intermittently run, the reference CTL does not appear every other field.

Therefore, conventional technology cannot be applied as is, and CT
For fields without L, there is a problem in that a reference to replace CTL must be interpolated in some way.

In addition, in the conventional technology, the tracking range is
It was limited to the time from the moment the speed reached enough to regenerate L until the brake timing. However, when one-track intermittent running is performed, the tape feed amount is halved, and if the same limitations as in the prior art are used, there is a problem that the tracking range becomes extremely narrow.

The present invention solves these problems, performs stable one-track intermittent running, and realizes good double-field reproduction slowness.

Means for Solving the Problems The magnetic tape running control device of the present invention counts capstan FG pulses (hereinafter referred to as FG) for one track (hereinafter referred to as N1) from the CTL and calculates a pseudo Generates a control signal (hereinafter referred to as pseudo-CTL),
Even if CTL is missing, FG from the previous pseudo CTL
a first counter that counts N1 and generates a pseudo CTL, and a second counter that counts the operating period clock of a delay circuit whose delay time can be varied and stores the number as a tracking number until one intermittent run is completed. counter, and in fields where CTL does not appear in intermittent running, the FG is calculated from the CTL regenerated in the previous intermittent running.
A third counter that generates brake timing by counting the tracking number and 13 Hage in the field where CTL is reproduced tracks FG from the pseudo CTL that was generated by the first counter in the previous intermittent run. This configuration includes a fourth counter that counts the number of brakes and generates brake timing.

Function: In the magnetic tape running control device of the present invention, the first counter counts N1 FG from the CTL reproduced during intermittent running to generate a pseudo CTL, and the second counter uses a delay circuit, such as an analog Count the clock during the ON period of the monomulti and store that number as the tracking number until one intermittent run is completed, and in the field where CTL does not appear during intermittent run,
CT played in the intermittent run before the third counter
When FG is counted from L and the number reaches the tracking number, brake timing is generated, and in the field where CTL is played, the fourth counter is a pseudo-simulator where the first counter occurred during the previous intermittent run. When the FG is counted from the CTL and the number reaches the tracking number, a pre-kiku 14-head noiming is generated, thereby realizing intermittent running of one track and one field. Also, set the first counter to CTL
Even if F is missing, F
By counting G by N1 to generate a pseudo CTL and resetting the third counter instead of CTLO, stable intermittent running of one track and one field can be performed even when CTL is missing.

Embodiment Hereinafter, a magnetic tape running control device according to an embodiment of the present invention will be described with reference to the drawings.

First, at the first speed v1, the tracking number (hereinafter,
It is abbreviated as Ntl. ) is set larger than the number of FGs for one track N1, the capstan drive current (cr) in FIG. 6, the tracking delay circuit in FIG.
Hereinafter, it will be abbreviated as tracking MM. ) (Foundation), tracking counter (F), CTL waveform shaping circuit (0), pseudo CTL counter (C), comparator (B), brake counter (B), and pre-15" Ichiki counter (timing representing the relationship of A). The charts are a, b, c, d, e, and f in Figure 1, respectively.

An outline of the intermittent running operation for one track and one field will be explained as shown in q and h.

Current changes A, B, C, and D in Fig. 1a each represent one track intermittent running, and CTL is reproduced in the field recorded in tracks A and C, and recorded in tracks B and D. CTL is not played in the field where At the timing shown in Fig. 1, the tracking MM (goods) in Fig. 6 is triggered, and the tracking counter (b) in Fig. 6 counts the clock h as shown in C. The number is stored as the tracking number Nt1. The capstan motor 3 is started at timing 3, and at timing t4, when the transition period of the regeneration state of the FG ends, the pseudo CT shown in FIG.
The L counter (c), the brake counter (tsu), and the brake counter (to) start counting FG, and the numbers increase as shown in e, q, and h of FIG. 1. At this time, e and q hold the value obtained by counting FG from the CTL reproduced in the previous intermittent running A.

Next, at timing t6, the value e of the pseudo CTL counter (c) in FIG. 6 reaches N1, and the comparison calculator ←) in FIG. Reset the value e of the counter (c) and the value of the brake counter (b). At this time, the pseudo CTL output from the comparator (b) becomes the reference for determining the brake timing for the next intermittent running C.

Next, at timing 70, the value q of the brake counter reaches the tracking number Nt1, and the value q of the brake counter reaches the tracking number Nt1.
generates a brake timing, intermittent running B enters a brake period, and at timing t7, the capstan motor 3 stops, and a field still state is entered. During this time, the tracking counter c7) is reset, the tracking MM (goods) is triggered again, and a new Ntl is stored.

Next, at timing t9, the capstan motor 3 is started, and intermittent running C is started. t9 to tl. Until,
Same as from t3 to t4 (transient period of FG regeneration 17A-S' state, pseudo CTL counter (c),
Brake counter (■, Brake counter (diagram)
It increases like e, q, h from the timing of tlo.

At this time, e and h hold the value obtained by counting FG from the pseudo CTL output by the comparator (b) in the previous intermittent run B. CTL like tll timing dd
is reproduced, and the value e of the pseudo CTL counter + U and the value q of the brake counter (value) are reset. This CTL
becomes the standard for determining the brake timing for the next intermittent run. At the timing of tl2, the value of the brake counter (2) reaches the tracking number Nt1, the comparator (c) in FIG. The capstan motor 3 stops at the appropriate timing and enters the field still state.Thus, one track and one field intermittent running is performed.

Next, an outline of the one-track, one-field intermittent running operation when the tracking number Nt1 is set to the same number as N1 will be explained with reference to FIG.

Changes in current A, B, C, and D in Figure 2a each represent one intermittent run on one track, and CTL is reproduced in the fields recorded in tracks A and C, and CTL is reproduced in fields B and D. CTL is not reproduced in the field recorded on the track. At the timing tl in FIG. 2, the tracking MM (goods) in FIG. 6 is triggered, and the tracking counter in FIG.
The number is stored as the tracking number Nt1 at the discharge timing of the two tracking MMs (goods). At timing t3, the capstan motor 3 is started, and at timing t4, when the transition period of the regeneration state of the FG ends, the pseudo CTL counter (brake counter) shown in FIG.
, and the brake counter (1) starts counting FG, and the number increases as shown in e+ q+ h in FIG. At this time, e and q hold the value obtained by counting FG from the CTL reproduced in the previous intermittent running A.

Next, at timing t5, the value e of the pseudo CTL counter e') reaches N1, and the comparator (b)
″-Output pseudo CTL to the sea urchin, pseudo CTL counter (1)
The value e and the value of the brake counter (■) are reset. At this time, the pseudo CTL output from the comparator (b) becomes the reference for determining the brake timing for the next intermittent driving C. At the same time, the brake counter (■) is reset. The value q of counter 0) is
When the tracking number Nt1 is reached, the comparator generates a brake timing, the intermittent running B enters the braking period, and the capstan motor 3 is stopped at timing t6, resulting in a field still state. During this time, the tracking counter (go) will be reset and the tracking M
M (goods) is triggered and newly stores Ntl.

Same as before (transient period of FG regeneration state, pseudo C
The TL counter (/tsu, brake counter (tsu), brake counterre) is e, q from the timing of t9.
, h. At this time, e and h hold the value obtained by counting FG from the pseudo CTL output by the comparator (b) in the previous intermittent running B. At timing tlo, the CTL is regenerated as shown in d, and the value e of the pseudo CTL counter (c) and the value q of the brake counter (b) are reset. This CTL becomes the standard for determining the brake timing for the next intermittent driving. At the same time,
Brake counter (value is tracking number Nt)
1, the comparator (b) in FIG. 6 generates a brake timing, and the intermittent running C enters the braking period, tll
The capstan motor 3 stops at the timing of , and enters the field still state. As described above, intermittent running for one track and one field is performed.

Next, an outline of the 1-t2-1-field intermittent running operation when the tracking number Nt1 is set to a smaller number than N1 will be explained with reference to FIG.

Current changes A, B, C, and D in Figure 3a each represent one track intermittent running, and the CTL is reproduced in the field recorded in tracks A and C, and recorded in tracks B and D. CTL is not played in the field where At the timing tl in FIG. 3, the tracking MM 21''-ji in FIG. 6 is triggered, one tracking counter in FIG. The number is stored as the tracking number Nt1 at the discharge timing. At timing t3, the capstan motor 3 is started, and at timing t4, when the transition period of the regeneration state of the FG ends, the pseudo CTL counter e→, the brake counter, and the brake counter in FIG. Start counting and start counting.
The number increases like qs h. At this time, e+q holds a value obtained by counting FG from the CTL reproduced in the previous intermittent running A.

Next, at timing t6, the value q of the brake counter (2) reaches the tracking number Nt1, the comparator (b) in FIG. 6 generates a brake timing, and the intermittent running B enters the braking period.

Next, at timing t6, the value e of the pseudo CTL counter (c) in FIG. e and the value h22 of the brake counter (■) is reset. At this time, the pseudo CTL output by the comparator is the reference for determining the brake timing for the next intermittent running C. 17# (Mink capstan motor 3 stops and enters the field still state.During this time, the tracking counter is reset, the tracking MM is triggered again, and a new Ntl is stored.

Next, the capstan motor 3 is activated at timing 70, and intermittent running C is started. From t9 to tlo,
Same as from t3 to t4 (this is a transition period of the regeneration state of FG, and the pseudo CTL counter C, brake counter (B), and brake counter (2) increase as esq and h from the timing of tl. At this time, e, h
holds the value obtained by counting FG from the pseudo CTL output by the comparator (b) in the previous intermittent running B. At the timing of tll, the value of the brake counter (b) reaches the tracking number Nt1, the comparator C) in FIG. 6 generates a brake timing, and the intermittent running C enters the braking period. At timing t12, CTL23''-7 is reproduced as shown in d, and the value e of the pseudo CTL counter (c) and the value q of the brake counter (2) are reset.

This CTL becomes the standard for determining the brake timing for the next intermittent driving. At the timing tl3, the capstan motor 3 stops and enters the field methyl state. As described above, intermittent running for one track and one field is performed.

Next, an outline of the intermittent running operation for one track and one field when the tracking number Ni1 is set to a larger number than N1 and the CTL is missing in the field where the CTL should be reproduced will be explained using FIG. do.

Current changes A, B, C, and D in Fig. 4a each represent one track intermittent running, and CTL is reproduced in the field recorded in tracks A and C, and recorded in tracks B and D. CTL is not played in the field where However, in this case, the CTL to be regenerated in intermittent running C
Assume that the tape is missing due to scratches on the tape. tl in Figure 4
From tl.

Up to this point, the same operations as from tl to tlo in FIG. 1 are performed. CTL to be played at the timing of tll in Figure 4
is missing. However, at approximately the same timing, the pseudo CTL counter (c) counts FG from the pseudo CTL generated by the comparator (b) in the previous intermittent run B, and reaches N1. Comparison operator (
The pseudo CTL output by (b) is based on the CTL regenerated in any intermittent run, and even if all CTLs are missing after that, the pseudo CTL counter (
/→ and the brake counter (2) are configured to reset the pseudo CTL counter (e) and brake counter (2) at even-numbered intermittent runs. Therefore, if the CTL regenerated in intermittent running A is used as the starting point, intermittent running C will be 3.
When the intermittent running starts, the comparator (b) outputs a pseudo CTL at the timing of tll, resets the brake counter (2) in place of CTL, and creates a reference for the brake timing for the next intermittent running.

t12. The timing of tl3 is “12jt” in Figure 1.
It works the same as 13. As mentioned above, even if CTL is lost, the stable 1-track 1-fee 25'\
- Can perform intermittent silt running.

Also, intermittent running A, C and 4 in Figures 1, 2 and 3
In intermittent running A in the figure, if the tape stretches due to temperature characteristics, the pseudo CTL counter e → reaches N1 earlier than the timing at which CTL is played, and the pseudo CTL counter (c) and brake counter (//) Sometimes it has to be reset.

However, since the configuration is such that the two counters are reset at the timing when the CTL is played back, the CTL is reset every two tracks, that is, every frame.
The criteria for intermittent running will be controlled by this. Therefore, even if the position of the pseudo-CTL between the CTLs fluctuates somewhat and an error occurs in the tape travel distance by one track, two
It is corrected for each track, allowing stable intermittent driving on one track and one field.

Furthermore, the first. Second. The CTL and pseudo-CTL shown in Figures 3 and 4 are the standards for determining the brake timing for the next intermittent run, so the FG regenerated during that time is
The number of O and the number of tracking 26 "-1' Ntl are equal. Also, the number of FGOs regenerated between the brake timings of each intermittent running N is several examples 1. Therefore, CTL
If Ntl is greater than N1 as shown in Figures 1 and 4, the position where the pseudo CTL appears is the position where the tape is at a speed sufficient to reproduce the CTL, before the brake timing. As shown in Figure 2, when Ntl is equal to N1, it is synchronized with the brake timing, and as shown in Figure 3, Ntl is equal to N1.
If l is smaller than N1, it will occur after the brake timing.

As described above, by varying Ntl before and after N1 using the tracking MM (incorporated), the tracking range can be set to a range sufficient for the tape to reproduce CTL when running intermittently.

Next, we will explain the case where Ntl is set larger than N1 at the first speed using the magnetic tape running control device for performing the operations shown in FIGS. 1 to 4 using FIGS. 5 to 8. explain.

In FIG. 5, 1 is a capstan control device, 2 is a capstan drive device, 3 is a capstan motor, and 4 is a two-phase FG generator.

27 When the hege tape is stopped and in the field still state, the sending pulse d is input to the tracking counter (reset terminal) and FF1 at the timing tl in Fig. 6.The tracking counter (b) is reset at this time. be done.

Since FF4 is L at timing t2 in FIG. 6,
The falling edge pulse of the head SWc serves as a trigger to start the start time MM) and the tracking MM. The tape is started at a fixed timing (hereinafter abbreviated as start timing) based on the reference signal SWc of the video head following the recording trajectory.
If this is not done, good reproduction output of the video signal will not be obtained during the transition period of intermittent running. Therefore, the sending pulse d is changed to FF1.
The rising edge or falling edge of the head SWc is input to the start time MM (incorporated) through ANDl as a trigger for generating the start timing. The reason for using the rising or falling edge of the head SWc as the trigger is because the video signal is azimuthally recorded by the L head and the R head as shown in FIG. From field still image playback, one track is intermittently traveled and the R head is used to perform field still image playback on the recording track, and from field still image playback on the recording track using the R head, one track is intermittently traveled and the L head is used to perform field still image playback on the recording track. This is because the head used at the beginning of the transition period is different when performing field still image playback. Furthermore, since the recording track and CTL 5 are in a fixed positional relationship as shown in Figure 9, based on the CTL reproduced during any intermittent running, the falling edge is set in the odd-numbered intermittent running, and the falling edge is set in the even-numbered running. The FF3 and FF4 shown in FIG. 6 are configured to use the start-up during intermittent running. F in Figure 6
Fs is reset by the waveform shaping circuit output of CTL), and is set to 1 by the pseudo CTL output from the comparator (b).
It is reversed every intermittent run. FF3 is held by FF4 using the start time MM) as a trigger, and its output controls SW1 and SW2.

29 At the timing t3 in Fig. 6, the tracking counter 5 counts the clock h while the tracking MIJ5 is in operation, reaches Ntl, and enters the multiplier.

The tracking number Nt1 is Nt=T, where the operating time of the tracking MM (incorporated) is T1 and the clock cycle is tck.
/lck, multiplier) responds to speed command a.
g 1 speed iV 1 speed Nt1=N t, second speed v
2 Teha, Nt2=Nt×(v2/v1), third speed v
3 Teha, N, 3=Nt x (V3/V1)O calculation is performed and stored in the tracking memory (G) as a tracking number. This eliminates the need to switch (T can be approximately the same value and use a capacitor or resistor depending on the speed) for each speed mode, and the circuit configuration becomes simple. 6th
At timing t4 in the figure, start time MM(A) is F.
F4. FF6. FF7 and FG count gate MMi
trigger. The outputs of FFe and FFy are input to a three-value encoder (three-value encoder), and the output thereof is input to the capstan drive device 2 as a capstan current limit command signal.゛The ternary encoder is FFe is L, FFy
When is L, L3o Hage is set, FFe is H, FF7 is L, M is set, FFa is H, F
Since F7 outputs H when F7 is H, the capstan motor 3 is started at this timing and the tape starts running.

At timing t6 in FIG. 6, the transition period of the FG regeneration state ends, the FG count game) MMi triggers FF2, and the capstan motor 3 rotates in the forward direction shown by arrow 3 in FIG. 9. , that is, the rotation direction detection circuit output ■ is L
During this period, both rising and falling edge pulses of the two-phase FG are output from AND3, and the FG is currented by the pseudo CTL counter (brake counter (3) and brake counter (g). From t4 to t in Figure 6
The reason why the transition period of the regeneration state of FG 6 is not counted is 2.
The transient characteristics of the capacitor of the bypass filter for cutting the DC component between the phase FG generation circuit 4 and the amplifiers (3) and FG1 and FG2 (Y) are shown in the waveforms of the next stage as shown in Figures 7 and 8. This is because it affects the shaping circuits (a) and (b) and causes errors. Figure 7 shows that when the cutoff frequency is low, the AC is superimposed on the DC fluctuation, creating a difference between the bias of the waveform shaping circuits (a) and (b), and the signal changes accurately. This is an example where the information is not communicated to the FIG. 8 shows an example where the cuff-off frequency is high and the change in the signal at the time of starting the slow capstan motor is not transmitted to the waveform shaping circuits (2) and (b).

CTL is reproduced at timing t6 in FIG. Since CTL and pseudo CTL are input to the reset input of pseudo CTL counter P-3 through OR1, the counter is reset at this point, and even if CTL is missing, it is interpolated by pseudo CTL. CT is connected to the brake counter glue set input through OR2 and AND4.
L and pseudo CTL are input to 9, and F is input to AND4.
Since the output of F4 is also included, the counter is CT
It will be reset at the timing t6 in FIG. 6 when the L is regenerated and at the timing when the pseudo CTL is output in the odd-numbered intermittent driving based on the arbitrary intermittent driving in which the CTL is regenerated.

At timing t7 in FIG. 6, the value of the brake counter H) reaches Ntl, and the comparator calculates the full brake value MM.
Output the trigger to (a) and FF6. Comparison calculator (5)
contains the output of the brake counter (1) or brake counter (2) through SW2.

Since SW2 is controlled by FF4, the comparator (to) calculates the value of the brake counter (two) in the odd-numbered intermittent driving based on the intermittent driving in which the CTL is regenerated and any intermittent driving in which the CTL is regenerated. For even-numbered intermittent runs, the output of the brake counter (brake counter) is compared with Ntl. The full brake MM (A) is a monomulti that determines the time when the capstan current limit command signal output from I) to the three-value encoder is H during the braking period.
Its output goes into the reset of FF7. The output of FF5 is
This is the capstan direction command signal, and at this timing H
1 forward direction command, and the capstan drive device 2 causes current to flow in the direction in which the capstan motor 3 stops.

At timing t8 in FIG. 6, FF7 applies full brake M.
Reset by M(a), FFe is HlFFT is L
Therefore, the 33-hage capstan current limit command signal output by the three-value encoder 0) becomes M.

During the braking period, the capstan current limit command signal is switched from H to M in order to gently stop the tape.

At timing t9 in FIG. 6, the phase relationship between FGl and FG2 is reversed, and the rotational direction detection circuit 2 outputs H. Since the output of the rotation direction detection circuit (2) is input to AND3 through the inverter, at this timing, the pseudo C
TL counter (c), brake counter ((foundation),
And the FG count of the brake counter (2) stops. Also, since FFs and FFe are reset at the same time, FFe goes up, FFy goes to L, and the ternary encoder □l
) outputs the capstan current limit command signal,
When the capstan direction command signal output from the FF 5 becomes L, the capstan motor 3 stops. Through the operations from tl to t9 in FIG. 6, the first intermittent run in which the CTL is regenerated is completed, and the field steal state is entered.

At the timing of tlo in Fig. 6, the sending pulse d is connected to the reset terminal of the tracking counter (reset terminal) and FF134.
′−′ is input. The tracking counter (Kou) will be reset at this time.

At the timing tll in FIG. 6, FF4 is H, so the rising edge pulse of the head SWc serves as a trigger to start the tracking MM) and the tracking MM at the start time MM.

The timing of 11,1 in Figure 6 is the previous 12j
13 14 t3. t4. Same operation as t5.

At the timing of tl5 in Fig. 6, the pseudo CTL counter p
The value of -+ reaches N1, and the comparator (b) becomes a pseudo CCT.
Output L. ROM1, which is a read-only memory, has N
1. ROM2 has N2=N1*(V2/■1), R
OM3 contains the value Na=N1*(V3/V1), and the comparator (b) reads ROM1 at the first speed, ROM2 at the second speed, and ROM3 at the third speed.
use. Since CTL and pseudo CTL are input to the reset input terminal of the pseudo CTL counter (c) through QRl, the counter is reset at this point. The reset input terminal of the brake counter (b) has 36 nodes pseudo CTL input through AND5, and the output of FF4 is also input to AND5 through an inverter, so the counter The timing at which the pseudo CTL is output is reset at the even-numbered intermittent run based on the arbitrary intermittent run in which the CTL is regenerated.

At timing tl6 in FIG. 6, the value of the brake counter reaches Ntl, and the comparator outputs a trigger to the full brake MM (a) and FF5.

The timings of t1□ and t18 in FIG.
Same action as 9, tl. Through the operations from t to 8, the second intermittent run in which no CTL appears is completed, and the field still state is entered.

As described above, by repeating the operation from t to t18 in Fig. 6, stable intermittent running of one track and one field is achieved.
Able to make fine throws from both fields.

Further, by setting the speed command signal a to the second speed and the third speed, both field reproduction slows can be performed in the speed mode.

Effects of the Invention In the magnetic tape running control device of the present invention, the first counter counts N1 FG from the CTL reproduced during intermittent running to generate a pseudo CTL, and the second counter generates an analog monomultiplier that determines the tracking number. The period clock of a delay circuit coN such as a vibrator is counted, and the number is stored as a tracking number until one intermittent run is completed. In a field where CTL does not appear during intermittent run, the third counter is counted from the previous one. FG is counted from the CTL regenerated during intermittent running, and when the number reaches the tracking number, brake timing is generated, and the CTL
In the field where is played, the fourth counter counts FG from the pseudo CTL generated by the first counter in the previous intermittent run, and generates brake timing when the number reaches the tracking number. ,
CT only once every 2 tracks like VHS format
This realizes intermittent running of one track and one field of a magnetic tape on which no L is recorded. Also, even if the CTL misses the first counter in 37'-ji, the pseudo CTL is counted by counting FG by N1 from the position of the previous pseudo CTL.
By generating the TL and resetting the third counter instead of the CTL, stable intermittent running of one track and one field can be performed even if the CTL is missing.

Furthermore, if a variable range is provided so that the delay time of the delay circuit that determines the tracking number can be set before and after the tracking number N1, the position where the CTL and the pseudo CTL generated by the first counter appear will be different from the tracking number. If the number is greater than N1, before the brake timing,
If the tracking number is equal to N1, the vehicle is synchronized with the brake timing, and if the tracking number is smaller than N1, it is possible to realize intermittent running that occurs after the brake timing. That is, before and after the brake timing, and the tape is C.
The tracking range is expanded to a range at a speed sufficient to reproduce the TL.

Furthermore, the first step is to count the FG during the transition period when starting the capstan. If the third and fourth counters 38 are configured so that they do not operate, they will count FGs that are in an unstable playback state, causing fluctuations in the intermittent running amount of the tape and making running control unstable. It is possible to prevent this from happening.

Furthermore, since FG represents the absolute amount of tape travel, when recording and reproducing the tape with the tape running at a first speed v1, a second speed v2, and a third speed v3, the second
Equipped with a memory that stores the value of the counter by 1 at the first speed, by V2/V1 at the second speed, and by 73771 at the third speed as the tracking number until one intermittent run is completed. In this case, there is no need to drastically change the value of the capacitor or resistance of the delay circuit depending on the speed, and it is possible to simplify the circuit configuration and reduce costs.

[Brief explanation of the drawing]

FIG. 1, FIG. 2, FIG. 3, and FIG.
5 is a block diagram of a magnetic tape running device according to the 39th embodiment of the present invention; FIG. 6 is a timing diagram of signals of each part in FIG. 6; FIG. 8 and 8 are output waveform diagrams of the FCi amplifier and waveform shaping circuit in the same embodiment, and FIG. 9 is a recording format diagram of the VH8 system.
FIG. 10 is a timing diagram showing the operation of a conventional magnetic tape running control device that performs intermittent running of two tracks and one frame. FIG. 11 is a block diagram of a conventional magnetic tape running control device. FIG. 12 is a conventional magnetic tape running control device. FIG. 3 is a waveform diagram showing a tracking range of the travel control device.

Claims (4)

[Claims] (1) A magnetic recording format in which a video signal for one field of a television signal is recorded on one track of a magnetic tape, and a control signal is recorded in the longitudinal direction of the magnetic tape once every two tracks. A device that intermittently runs the tape one track at a time, and is reset at the time of playback of the control signal, counts capstan FG pulses for one track, generates a pseudo control signal, is automatically reset, and further controls the tape. A first counter that repeats the operation of counting capstan FG pulses for one track from the previous pseudo control signal and generating a pseudo control signal even if a signal is missing, and a counter that repeats the operation of generating a pseudo control signal by counting capstan FG pulses from the previous pseudo control signal, and before the magnetic tape is activated by the capstan. a second counter that counts the clock during the operation period of the delay circuit and stores the tracking number until one intermittent run is completed; The capstan FG pulse is counted from the control signal regenerated during intermittent running, and when the number reaches the tracking number in the current intermittent running, a third counter generates the brake timing and The first counter counts capstan FG pulses from the generated pseudo control signal, and in the current intermittent running,
a fourth counter that generates a brake timing when the number reaches the tracking number; The operation is based on a pseudo control signal generated by counting capstan FG pulses for one track from the signal position, and the brake timing for the current intermittent running is generated alternately with the fourth counter to intermittently run the tape. A magnetic tape running control device characterized in that it is configured to feed one track at a time. (2) The number of capstan FG pulses for one track is N
1, the delay time of the delay circuit can be varied so that the tracking number is from a number smaller than N1 to a number larger than N1, and the tracking range is set from the position where the control signal is reproduced before the brake timing. 2. The magnetic tape running control device according to claim 1, wherein the control signal is provided up to a position where the control signal is reproduced after the brake timing. (3) The first, third, and fourth counters are configured so as not to count capstan FG pulses during a transient period immediately after capstan activation. The magnetic tape running control device described above. (4) Run the tape at the first, second, and third speeds (first speed V1 > second speed V2 > third speed V3)
When running intermittently in a vehicle that is capable of recording and reproducing in the mode, the value of the second counter is multiplied by 1 at the first speed, multiplied by V2/V1 at the second speed,
Claim 1 or 2 further comprises a memory that multiplies the tracking number by V3/V1 at the third speed and stores it as a tracking number until one intermittent run is completed.
A magnetic tape running control device as described in .