JPS62146451A - Tracking control device - Google Patents

Abstract

PURPOSE:To track correctly a rotary head at the time of reproducing by extracting a tracking error signal within a prescribed period when a tape is traveling at the same speed as recording, and holding the extracted signal as a tracking error signal to be used when the tape is traveling at another speed. CONSTITUTION:A switch 43 is turned ever 180 deg. period synchronously with the rotation of heads Ha, Hb(Hb') by a signal outputted from a terminal 40. A pilot signal is extracted by passing an amplifier 44 continuously reproduced signal through an LPF 46. The gap width of the heads Ha, Hb(Hb') is set up equally to track width, reference pulses are generated synchronously with the successive scanning of tracks T1-T4 by respective heads, each reference pulse is multiplied 47 by the output of the LPF 46, signals DELTAfA, DELTAfB are extracted by BPFs 51, 52 and subtracted 55, and the subtracted signal is extracted 56 from a computer 8. If the head Ha is shifted like positions 71, 72, a reference signal having frequency different from that of the real reference signal is leaked from the adjacent track, a tracking error value is decided from the DELTAfA, DELTAfB and the head can be correctly tracked by controlling 8 the tracking error value.

Description

[Detailed description of the invention] The present invention will be explained in the following order.

A. Field of industrial application B. Overview of the invention C. Prior art D. Problem to be solved by the invention E. Means for solving the problem (Fig. 1) F. Effect G. Example G1 Automatic teller machine (Fig. 5) Figure) G2 Reproducing circuit (Figure 10) G3 Trafking control device (Figure 1) H Effect of the invention A Industrial field of application The present invention uses a rotary head to change the frequency of an information signal and between two adjacent tracks. A tape on which a pilot signal whose frequency changes cyclically is recorded to form an inclined track is run at a predetermined speed, the recorded signal is reproduced by a rotary head, and a reproduced pilot signal separated from the recorded signal is generated. The present invention relates to a tracking control device that controls the tracking of a rotary head during reproduction by comparing the signal with a reference pilot signal and supplying a trunking error signal obtained based on the comparison output to a tracking means.

B. SUMMARY OF THE INVENTION The present invention provides a method in which an information signal and a pilot signal whose frequency changes cyclically form an inclined track (a recorded tape is A recording signal is reproduced by a rotary head while traveling at the same speed and a different speed, and a reproduced pilot signal separated from this recording signal is compared with a reference pilot signal, and a tracking error signal is obtained based on this comparison output. In a tracking control device that supplies a tracking error signal to a tracking means to control tracking of a rotary head during playback, a tracking error signal is sampled at a predetermined timing when the tape is running at the same speed as during recording. By installing a sample hold circuit that holds this sample value as a tracking error signal when the tape runs at a speed different from that during recording, the rotation during playback when the tape runs at a speed different from that during recording. This allows for good head tracking control.

C. Prior Art Conventionally, a rotating head is used to run at a predetermined speed a tape on which an information signal and a biloft signal whose frequency changes cyclically, forming inclined tracks, are recorded with different frequencies between adjacent tracks. the recorded signal is reproduced by the rotary head, the reproduced pilot signal separated from the recorded signal is compared with a reference pilot signal, and a tracking error signal obtained based on the comparison output is supplied to the tracking means, A tracking control device (for example, see Japanese Unexamined Patent Publication No. 59-65962) that controls tracking of a rotary head during reproduction is known. Such a tracking control device is employed in a VTR called 8 mm video.

By the way, a VTR equipped with such a tracking control device
When recording video over a long period of time using a tape, for example, still image recording is performed in order to reduce the amount of tape consumed.

D. Problem to be solved by the invention When reproducing a still image from a certain part of the recorded signal on such a tape, there is no problem because the tape is stopped running and reproduced in the same way as when recording, but when the tape is moved. Since the scanning angle of the rotary head on the tape during playback is naturally different from the scanning angle during recording, a problem arises in that good tracking control cannot be performed.

In view of this, the present invention proposes a tracking control device that can perform tracking control well even when the tape is run at a speed different from that during recording and played back.

E Means for Solving the Problems The present invention uses rotary heads Ha and Hb to record information signals and pilot signals whose frequencies vary cyclically between two adjacent tracks so as to form inclined tracks. The recorded tape (21) is run at the same speed as when recording and at a different speed, and the rotating head Ha+ Hb+
The recorded signal is reproduced by Hb', the reproduced pilot signal separated from the recorded signal is compared with the reference pilot signal, and the tracking error signal obtained based on this comparison output is supplied to the trunking means, In a tracking control device designed to control the tracking of the rotating heads ■a, Hb, and Hb' of the tape (
21) Sample hold that samples the tracking error signal at a predetermined timing when the tape is running at the same speed as when recording, and holds this sample value as the tracking error signal when the tape runs at a different speed than when recording. It is characterized in that a circuit (56) is provided.

F Effect According to the present invention, even if the tape (21) is run at a speed different from that during recording and the recorded signal is reproduced, the tape (21) is run at the same speed as during recording and the recorded signal is reproduced. The tracking error signal when playing back the signal is sampled, and this sample value is held as the tracking error signal when playing back the recorded signal by running the tape (21) at a different speed than when recording. However, tracking control can be performed well.

G. Embodiment Below, an embodiment in which the present invention is applied to a VTR of a monitoring device for an automatic teller machine (including an automatic teller machine, an automatic teller machine, an automatic teller machine, etc.) will be described in detail. .

G□Automated Teller Machine First, the overall structure of the automatic teller machine will be explained with reference to FIG. In the figure, (1) shows the automatic teller machine itself, and (2) shows the monitoring device. By integrating this monitoring device (2) with the automatic teller machine main body (1), it becomes compact as a whole, and can be installed in financial institution stores, supermarkets, and other retail stores, or as an independent unit. Easy to install and low source of energy. Of course, these can also be constructed separately.

First, the automatic teller machine body (1) will be explained.
This has the same configuration as the conventional device, with a microcomputer (3) connected online to the host computer at the center, and a microcomputer (3) connected to the host computer at the center.
3), a date and time data generator (can be built into the microcomputer (3)) (4), an input device (having a numeric keypad, function keys, etc.) (5), an input device (5) ) microcomputer based on key operations (
3) A display device such as a CRT (6) that displays messages from
), a printer (7) for printing the depositor's name, financial institution code, depositor number, payment amount, balance amount, etc.

Next, the monitoring device (2) will be explained. (8) is a microcomputer as a control device.

This microcomputer (8) processes transaction data (date and time data, depositor name, financial institution code, depositor number, payment amount, balance amount) from the automatic teller machine (1), such as date and time. It receives data (for example, 7-bit ASCII code data), a 1-bit strobe, and a confirmation signal to be described later.

(16) is a detector that detects when there is a human figure near the front of the automatic teller machine (1). (detects infrared wavelengths). Incidentally, as this detector (16), an ordinary infrared sensor, radio wave sensor, etc. can also be used.

(12) is a video camera for capturing images of the user (or the user and his/her left behind) in a plurality of main scenes of leaving behind between the user and the automatic teller machine main body (1); A COD or an image pickup tube may be used as the image pickup device. (11) is a synchronization separation circuit that separates a synchronization signal from the imaging signal from the camera (12).

(14) is a VTR, and here an 8 mm video type is used to reduce the size of the device. (15) is a monitor receiver.

(9) is a timing circuit for television scanning synchronization for converting date and time data (character data) from the microcomputer (8) into television signals, and a character/position data and synchronization separation circuit from the microcomputer (8). (1
1) receives horizontal and vertical synchronization signals from (10) is a character generator which receives date and time data from the microcomputer (8) and supplies the generated character signal to the television scanning synchronization timing circuit (9). Then, the imaging signal from the camera (12) and the date and time television signal from the television scanning synchronization timing circuit (9) are supplied to a synthesizer (13) and combined. This combined output is supplied to a VTR (14) to perform intermittent still image recording on a magnetic tape. This recorded tape is played back by this VTR (14) (another VTR is also possible) when necessary, and the playback signal is supplied to a monitor receiver (15) for playback.

FIG. 6 shows an example of an image reproduced on the monitor receiver (15). Although not shown, most of the screen contains the face and other images of the user of the automatic teller machine. For example, the year, month, and day are superimposed on the upper left side of the screen, and the hours, minutes, and seconds are superimposed on the lower right side of the screen. It's being served.

The television scanning synchronization timing circuit (9), character generator (10), camera (12) and VTR (14) are controlled by a microcomputer (8).

Next, referring to FIG. 7, the rotating magnetic head of the VTR (14) shown in FIG. 5 will be explained. In Figure 7, Ha
+ Hb and Hb' indicate rotating magnetic heads, each of which is attached to the tape guide drum D at a required interval. Rotating magnetic head Ha, rotating magnetic head Hb, Hb
', the azimuth of the magnetic gap is different from each other. The rotating magnetic heads Ha and Hb have an angular interval of 180 degrees and have a step corresponding to one track pitch on the tape. The rotating magnetic head Hb' has an angular interval corresponding to an integral multiple of the distance corresponding to one horizontal cycle period on the tape with respect to the rotating magnetic head Ib, and the difference in height from the rotating magnetic head Ha is zero.

Ba is a head substrate to which the rotating magnetic head Ha is attached, Bb is a head substrate to which the rotating magnetic heads Hb and Hb' are attached, and the head substrates Ba and Bb are at the same height. The gap width (height) W of the rotating magnetic heads )la, )lb and 11b' is both 25 μm, and the height between the upper end of the gap between the rotating magnetic heads Ha, Hb' and the lower end of the gap between the rotating magnetic head Hb is 25 μm. The difference is 4.5
It is μm.

When recording on a VTR (14), the tape is advanced intermittently, and when stopped, two video signals for one frame (two fields) are recorded onto the magnetic tape by rotating magnetic heads Ha and Hb. Recording is performed so as to form an inclined track. V
When reproducing TR (14), the rotating magnetic head Ha+H
Cue playback (tape speed is about 7 times the normal speed) and review playback (tape speed is about 9 times the normal speed) are performed at b', and the rotating magnetic heads Ila, t
Still images are played back from a magnetic tape that is intermittently fed at 1.5 lbs.

Next, with reference to FIG. 8, the operation when using the automatic teller machine will be explained. The operation starts at step 5T-0.

First, in step 5T-1, when the detector (16) detects a human figure near the front of the automatic teller machine main body (1), in step 5T-2, the drum motor of the VTR (14) is rotated. The speed is 1/3 times the steady speed to 1
It can be doubled. Thereafter, in step 5T-3, the recording command signal shown in FIG. 9B is given from the microcomputer (8) to the VTR (14), and the tape is recorded as shown in FIG. 9A.
As shown in the figure, the vehicle runs at a steady speed, then stops, runs again at a steady speed, then stops, runs at a steady speed again, and then stops. When the tape stops, the image signal from the camera (12) is transmitted three times at one-second intervals.
The signal on which the date and time signal is superimposed is recorded three times in frame units on the VTR (14) (first recording).

Next, in step 5T-4, the automatic teller machine body (1)
When the insertion of the cash card into the card insertion slot is detected, in step 5T-5, the microcomputer (3
) outputs a card insertion confirmation signal, and as a result, in step 5T-6, the VTR (14) performs the following operations as shown in FIG.
The second recording is performed in the same manner as the first recording.

Next, in step 5T-7, when it is detected that the user's key input of the PIN number and withdrawal amount has ended, in step 5T-8, the microcomputer (3) sends the transaction to the host computer of the center. make a request. If the host computer approves the transaction in step 5T-9, the payment is made in step 5T-10.

In step 5T-9, if there is no transaction authorization from the host computer (the PIN numbers do not match or there is no bank balance to meet the payment request),
The process advances to step 5T-18, which will be described later.

In step 5T-11, when the microcomputer (3) outputs a monetary payment confirmation signal, step 5T-1
At step 2, the VTR (14) performs a third recording similar to the first recording as shown in FIG.

Next, in step 5T-13, when it is detected that the money has been delivered to the user, the microcomputer (3) outputs a money acquisition confirmation signal in step 5T-14, and in step 5T-15, the microcomputer (3) outputs a money acquisition confirmation signal. , the VTR (14) performs the fourth recording similar to the first recording as shown in FIG.

In step 5T-16, if the user makes continuous transaction requests to the automatic teller machine (1) such as withdrawing money again, checking the balance, etc., step 5T-16
Returning to step 5T-7, if there is no such request, step 5T-17
Proceed to. In step 5T-17, when it is detected that the card has been handed over to the user, a card acquisition confirmation signal is output from the microcomputer (3) in step 5T-18, and in step 5T-19, the VTR (14) As shown in FIG. 9, the fifth recording is performed at the same time intervals as the first recording, and the recording is repeated up to step 5T-21.

In step 5T-20, when the detector (16) no longer detects a human figure, in step 5T-21, the VTR (14)
) recording (fifth recording) ends. Then, in the next step 5T-22, the rotational speed of the drum of the VTR (14) is decreased from 1 to 1/3 times the steady speed.

The operation then ends at step 5T-23.

G2 playback circuit Next, referring to FIG. 10, the VTR (14) shown in FIG.
The playback circuit (playback circuit for retrieving images on tape) will be explained. Reference numeral 21 denotes a magnetic tape, on which a still image of a video signal and a superimposed signal of a date and time signal from the above-mentioned camera (12) is recorded. (22) is a rotating magnetic head corresponding to the above-mentioned rotating heads Ha, Hb, and Hb'. A reproduction signal from this rotating magnetic head (22) is supplied to a reproduction circuit (24) through an amplifier (23).

The baseband video signal obtained from the reproduction circuit (24) is sent to a gate circuit (25) for extracting a date and time signal.
supplied to The video signal from the reproduction circuit (24) is
1A, Sc1 indicates its date and time signal, VD
indicates the vertical synchronization signal. A temporally expanded version of this video signal is shown in FIG. 11B. SC,2 indicates the date and time signal, and HD indicates the horizontal synchronization signal. and,
The baseband video signal from the reproduction circuit (24) is supplied to a synchronization separation circuit (26), and vertical and horizontal synchronization signals VD and HD are extracted. Of these, the vertical synchronization signal VD is supplied to the gate circuit (25), where the date and time gate signal G1 shown in FIG.
), the date and time signal (12-digit date and time signal) SC3 shown in Figure 11 is extracted.

The 12-digit date and time signal from the gate circuit (25) is supplied to another gate circuit (27). Synchronous separation circuit (2
6) The horizontal synchronization signal HD from digit selection signal generation circuit (2
8), and the digit selection signal obtained therefrom is supplied to the gate circuit (27). And this gate circuit (
27), the 12-digit date and time signal is January 2, 2017, 3:01.
The signal is gated in the order of minutes and 1 second and is supplied to the next stage slicer (29), so that its amplitude is kept constant.

The output of the slicer (29) is fed to a programmable logic array (PLA) (30). This PLA
A part of the configuration of (30) will be explained with reference to FIG. Thus, FIG. 14 shows a display pattern for numbers representing date and time, which is composed of seven display elements a to g in the Japanese character shape as a whole.

For example, elements a, d, and g are composed of three television scanning lines, and elements s, c, e, and f are composed of six scanning lines. Thus, element 2-g of this Figure 14
The luminance signal for forming the image is as shown in A to G in FIG. Therefore, in FIG. 12, input terminals Ta to Tg are provided to which signals obtained by selecting signals from A to G in FIG. 13 according to numbers 0.1 to 9 are supplied. And input terminal T
a”Tg are directly connected to the lines Lat to Lgt, respectively, and connected to the lines L through inverters IVa to IVg, respectively.
Connect to a2 to Lg2. Then, provide an output terminal corresponding to each number 0, 1 to 9, connect this output terminal to a power source through a resistor, and connect the output terminal to the number of lines Lat to t, g and lines La2 to Lg2. By connecting separate diodes between the input terminal Ta''Tg and the selected number, a signal corresponding to a certain number (
(see FIG. 13) is supplied, the output rlJ is obtained at the output terminal corresponding to that number. 12th
In the figure, for simplicity, only the circuit that outputs "1" to the output terminal N-8 corresponding to the number -8 when all the signals of G shown in FIG. 13 are supplied to the input terminal Ta=Tg is shown. is illustrated.

Therefore, the output terminal N-8 is connected to the power supply terminal B through the resistor R.
The anodes and cathodes of the diodes Da-Dg are connected between the output terminal N-8 and the lines Lat-Lg1, respectively.

Therefore, the output of PLA (30) is the latch circuit (31)
and its output is supplied to a matching circuit (32). (34) is an input device that manually enters the data of 1:02:02 on January 9, 2019, and this data is input to the latch circuit (33
), and its output is supplied to a matching circuit (32) and compared with the output of the latch circuit (31). Then, the output of the coincidence circuit (32) is supplied to the drive circuit (35), and the output is supplied to the capstan motor (37) via the inhibition circuit (36). Further, the match output from the match circuit (32) is supplied to the inhibition circuit (36).

Thus, in order to obtain a reproduced image of the desired date and time from the tape based on the recorded data of the microcomputer (3) or the host computer, the tape must be transferred to the VTR.
(14) to play the cue or review, and match circuit (32).
) at 9 o'clock on January 9th.

When the minutes match, the capstan motor (37) is driven intermittently to play back still images on the tape in the same way as when recording.
Continue this until the seconds match to get the desired image.

G3 Tracking Control Device Next, the above-mentioned VTR tracking control device will be explained with reference to FIG. Rotating magnetic head Ha, H
b()lb') are respective amplifiers (23a).

(23b), the head switching signal RFS is supplied to the switch circuit (43) from the terminal (40).
W (FIG. 3A), this switch circuit (43) synchronizes with the rotation of the rotating magnetic healds Ha and Hb (Hb'), so that the head Ha or Hb (Hb') scans the tape by 180 degrees. It is alternately switched to one and the other terminal for a period of an angular interval. Therefore, the amplifier (44
) as the outputs of head Ha and Hb ()Ib')
A signal in which the playback output of is continuously connected is obtained,
This is connected through the terminal (45) to the regeneration circuit (24) (10th
Figure).

The output of the amplifier (44) is supplied to a low-pass filter (46) to extract a pilot signal from the reproduced signal. The reproduced pilot signal from this low-pass filter (46) is supplied to a multiplication circuit (47).

Now, as shown in FIG. 2, on the tape (21), every other track T1. T
3 is formed and an FM-modulated video signal is recorded, a pilot signal of frequency f1 is recorded on track T1, a pilot signal of frequency f3 is recorded on track T3,
Each is recorded in a superimposed manner. Also, this tape (21
), every other track T2°T4 is sequentially formed by the other rotary head Hb to record an FM modulated video signal, and track T2 receives a pilot signal of frequency f2, and track T4 receives a pilot signal of frequency f2. The f4 pilot signals are respectively superimposed and recorded. By repeatedly recording these tracks T1 to T4, pilot signals of four different frequencies are also sequentially and cyclically recorded to these tracks T1 to T4.

Tracking control during playback is performed as follows.

In this case, the head Ha is in the just tracking state when it correctly scans the tracks T1 and T3, and the head Ilb (Hb') is in the just tracking state when it correctly scans the tracks T1 and T3.
Just tracking occurs when the image is scanned correctly. Therefore, assuming that the gear widths of heads Ha and Hb match the track width, head Ha
, Hb (tlb') sequentially scans tracks T1 to T4, in synchronization with this, signals P1 to P4 with frequencies f1 to f4 are supplied as reference pilot signals to a multiplier circuit, and the frequency with the reproduced pilot signal is When the difference is detected, no frequency difference is obtained in the state of Jas l-) racking.

On the other hand, the tracking position is the head position (
This is for head Ha) If there is a deviation as shown in (71) and (72), a pilot signal with a frequency different from the reference pilot signal from the adjacent track will be obtained as crosstalk, so the crosstalk will be A frequency difference occurs between the signal and the signal, and the level is proportional to the amount of difference.

Therefore, the frequency f is adjusted such that the frequency difference is the same in the direction of deviation between tracks T1 and T] and T2 and T.
By selecting 1 to f4, tracking servo can be easily performed. That is, AfA=l ft - ft 1=l r3 - f41Δf
s=lf2-f31=lr+r,l. In this way, the existence of the frequency difference ΔfA is shifted to the right with respect to the head Ita, and the existence of the frequency difference ΔfA is shifted to the right with respect to the head Ilb (Ilb'
) means left shift, and the existence of frequency difference ΔfB means left shift for head lla, head Hb (Hb')
means a shift to the right, and the levels of the differences ΔfA and ΔrB are proportional to the amount of shift.

Therefore, in principle, these frequency differences ΔfA.

Δfs indicates the amount of tracking error, and if this is controlled to become zero, just tracking can be achieved.

However, since this example is a case of overwriting, as shown by the solid line (73) in Fig. 2, just tracking is a state in which the track that is originally to be scanned is scanned across tracks on both sides of it by slightly the same amount. state. In other words, just tracking occurs when the levels of the frequency differences ΔfA and Δf are equal, and tracking control is performed by controlling so that the level difference between the differences Δ[A and ΔfB becomes zero.

This example is an example of an 8 mm video, where the pilot signal is a signal that is even lower than the band of the low-pass conversion carrier color signal, and has four frequencies f1. f2゜f3. For example, f4 is f r = 102kllz, r 2 = 1
16kHzf3=160kHz, f4=
Selected as 146kHz, ΔfA"" 14kHz
, Δr B = 44kHz.

Returning to FIG. 1 again, a pilot signal generation circuit (48) is provided, and from this, the frequency f + f
2+fx+f+ reference pilot signal PL, P2. P
3. P4 are obtained and these are supplied to the switch circuit (49). This switch circuit (49) is supplied with select signals SL1 and SL2 from the switch control circuit (50), and these select signals SL1. 4 by SL2
One of the pilot signals of different frequencies is selectively taken out from this switch circuit (49). The switch control circuit (50) is supplied with the head switching signal RFSW from the terminal (40), and select signals SL1 and SL are activated at the rising and falling points of this signal RFSW.
2 is changed, and the reference biloft signal obtained from the switch circuit (49) is changed. For example, during the 180° period when the head Ha scans the track T1 in FIG. 180° scanning T2
During the period, signals P1 to P4 of four frequencies are sequentially switched to obtain a signal P2 of frequency f2, and so on.

The reference pilot signal from this switch circuit (49) is supplied to a multiplication circuit (47). Therefore, from this multiplication circuit (47), signals with frequencies ΔfA and ΔfB, which are the difference between the reference pilot signal and the regenerated pilot signal, are obtained, and these are extracted by bandpass filters (51) and (52), respectively, and detected. Circuit (53
) and (54) to produce DC level outputs Sa and sb.

Detection outputs Sa and sb of the detection circuits (53) and (54)
are levels proportional to the amount of the frequency difference ΔrA and ΔfB components, that is, the magnitude of the pilot signal included as a crosstalk in the reproduced pilot signal,
This corresponds to the tracking amount of the right and left adjacent tracks.

These detection outputs Sa and sb are supplied to a subtraction circuit (55), and a subtraction output SD of both is obtained. This subtraction output SD is a signal indicating which side is more deviated, left or right. As mentioned above, the frequency differences Δf8 and ΔfB are different from each other when the head Ha is scanning and when the head Hb (Hb
') The direction of the shift is opposite to that when scanning.

Therefore, the output SD of the subtraction circuit (55) is held as it is during cue and review playback, and during normal 1x speed playback, and is held as a sample during step playback (when the tape is repeated, running at 1x speed, and playing with the tape stopped). It is supplied to each fixed contact of the switch circuit (57) via the circuit (56), and the output of the movable contact is left as is or the polarity of the output is inverted via the polarity inverting circuit (59) to the switch circuit (58). )
is supplied to each fixed contact. The switch circuit (58) is alternately switched by the head switching signal RFSW between the scanning of the head Ha and the scanning of the head Ilb (Hb'), so that the switching circuit (58) receives signals according to the direction of deviation. A tracking error signal SE is obtained.

Tracking error signal SE from switch circuit (58)
is transmitted through the combiner (60) and the drive amplifier circuit (61),
Capstan motor as tracking means (37)
is supplied to The rotation of the motor (37) causes the motor (
37) is detected by a frequency generator (not shown) provided integrally with the rotation detection signal, and the rotation detection signal is sent to the speed servo circuit (
62), and its servo output is supplied to the switch circuit (62) during cue and review playback, and during normal 1x speed playback.
3) to the combiner (60). Further, during step reproduction, a constant level signal (voltage) from the constant level signal generating circuit (64) is supplied to the synthesizer (60) via the switch circuit (63). Sample hold circuit (56
) performs sample and hold operations in response to a control signal P3 from a microcomputer (8) (see FIG. 1). Switch circuit (57).

(63) are respectively switched and controlled by a control signal Px from the microcomputer (8).

Next, with reference to FIG. 3, the operation of the tracking control device shown in FIG. 2 will be explained. In the target screen search, when cue or review playback (or steady playback) of the tape is being performed, the movable contact of the switch circuit (57) is connected to the fixed contact on the side of the subtraction circuit (55), and the switch circuit (63)
) are respectively switched to fixed contacts on the side of the servo circuit (62).

The tracking error signal SE obtained from the switch circuit (58) is then supplied to the synthesizer (60).

Further, a servo signal corresponding to the rotation of the motor (37) is supplied from the servo circuit (62) to the synthesizer (60), and the synthesized output is supplied to the motor (37) through the amplifier circuit (61).

Next, in the coincidence circuit (32) of FIG. 10, when the date and time match up to the minute, the tape passes through regular running and then is made to run in steps. In this way, the switch circuit (5) is activated by the control signal Px from the microcomputer (8).
The movable contact 7) is switched to a fixed contact on the side of the sample hold circuit (56), and the movable contact of the switch circuit (63) is switched to a fixed contact on the side of the constant level signal generation circuit (64).

Furthermore, in the microcomputer (8), FIG.
The control pulse P1 shown in FIG.
A pulse P2 that falls after 5 ec and a pulse P3 whose phase is inverted with respect to this pulse P2 are generated. This pulse P
During the low level period 3, the tracking error signal fluctuates as shown in FIG. 3I. Then, in the sample and hold circuit (56), the output of the subtraction circuit (55) is sampled at the time of the rise of this pulse P3, and this hold value is then held as a tracking error signal when the tape runs at a steady speed. be done. This hold output is fed to a combiner (60).

In the microcomputer (8), the pulse P shown in Fig. 3E is generated in coincidence with the rise of pulse P3 in Fig.
4 occurs. This pulse P4 is, for example, 40m5e
It falls down after a time of c or more. During the high level period of the pulse P4, an acceleration pulse (not shown) is generated from the constant level signal generation circuit (64) and supplied to the synthesizer (64) in coincidence with the rise of the head switching pulse RFSW. Then, the capstan is 3 shown in Figure 3F.
It rotates for a period of 6°1m5ec and then stops. Also,
From 3.5 m5 ec before the end of this capstan rotation until the end, the motor (37) receives a deceleration pulse (braking pulse) as shown in FIG. 3G from the constant level signal generation circuit (64). Supplied. Thus, the tape is the third
As shown in Figure H, the running speed increases from 0, the tape runs at a steady speed, the running speed decreases from the steady speed, and then the tape stops. While the tape is running, the synthesizer (60) is supplied with the hold output from the sample and hold circuit (56).

Incidentally, at the end of the rotation of the capstan in FIG. 3F, the pulse P1 in FIG. 3B rises and the above-described operation is repeated.

Also, when the sample hold circuit (56) is not provided,
As shown in FIG. 4B, FIG. 4A shows the tracking error signal when the tape travels in steps at one time the steady speed. This deviation in the tracking error signal is caused by the fact that the scanning angle of the rotating magnetic head with respect to the tape differs between recording and reproduction. Therefore, if a sample hold circuit (56) is provided and the sample value of the tracking error signal when the tape stops running is used as the tracking error signal when the tape is running in steps, this error in tracking control can be eliminated.

In addition, when the tape is played back in steps, the tracking of the rotating magnetic head Ha, I (when the tape running speed becomes 1x speed, the rotating magnetic head 1b) with a step becomes erroneous, and the playback is interrupted. The level of the high frequency signal decreases as shown in FIG. 4C. Therefore, a switching circuit (not shown) is used to use the rotating magnetic heads Ha, Hb when the tape is stopped running, and to use the rotating magnetic heads Ha, Ilb' when the tape is running stepwise at one time the normal speed. This problem can be solved by switching by .

Effects of the invention H According to the invention described above, tracking control of the rotary head during reproduction can be performed well when the tape is run at a speed different from that during recording.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the main parts of an embodiment of the present invention;
Fig. 2 is a pattern diagram showing a track pattern, Fig. 3 is a time chart for explaining the operation of the embodiment of Fig. 1, Fig. 4 is a waveform diagram, and Fig. 5 shows the entire embodiment of the present invention. Block diagram, Fig. 6 is a diagram showing a reproduction screen of a superimposed signal of an imaging signal from a camera and a date/time signal, Fig. 7 is a layout diagram showing a rotating magnetic head of a VTR according to an embodiment, and Fig. 8 is an implementation diagram. 9 is a time chart for explaining the operation of the example, FIG. 10 is a block diagram showing the reproducing circuit of the VTR of the embodiment, and FIG. 11 is a time chart for explaining the operation of the reproducing circuit. Chart, Figure 12 is a circuit diagram showing a part of the PLA circuit of the reproduction circuit, Figure 13 is a circuit diagram showing a part of the PLA circuit of the reproduction circuit.
FIG. 14 is a waveform diagram showing the signals supplied to the LA circuit, and a pattern diagram showing the display pattern. Ha, I(b, Hb' are rotating heads, (21) is a tape, and (56) is a sample and hold circuit.

Claims (1)

[Claims] A tape on which an information signal and a pilot signal whose frequency changes cyclically, with different frequencies between adjacent tracks, are recorded by a rotating head to form an inclined track, is moved at the same speed as when recording. and traveling at different speeds to reproduce the recorded signal with a rotary head, compare the reproduced pilot signal separated from the recorded signal with a reference pilot signal, and track the tracking error signal obtained based on the comparison output. In the tracking control device, the tracking error signal is sampled at a predetermined timing when the tape is running at the same speed as when recording. A tracking control device comprising: a sample hold circuit that holds the sample value as a tracking error signal when the tape runs at a speed different from that during recording.