JPS5931456A - Travel detector of recording medium - Google Patents

Abstract

PURPOSE:To detect a tape travel speed in case of a control system which records pilot signal of cyclically varying frequency on every track by generating a travel detection signal on the basis of waviness occurring to a reproduction tracking error signal. CONSTITUTION:The pilot signal detecting circuit 32 of a helical scan VTR, etc., detects the pilot signals of different frequencies recorded cyclically on respective tracks for tracking control, and the error signal generating circuit 3 generates a tracking error signal S3 for the frequency difference between the reproduction pilot signals. This signal is applied to a detecting circuit 32 for the number of a waviness period which performs a positive feedback Schmitt amplification, etc.; when the signal S3 exceeds a threshold value, a rising detection pulse S5 is generated in every waviness period of a signal S2. Then, pulses S5 are integrated by an arithmetic circuit 33 to detect securely a travel speed in a quick traversing mode, etc., on the basis of the waviness of period corresponding to the travel speed even in case of this tracking control system.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a recording medium line detection device, and in particular, the present invention relates to a recording medium line detecting device, and in particular, d-pin nails, medium 1, and soil are lined up in sequence across the traveling direction f, and a type of pilot signal f is circulated. It is recorded with (? + information) and reproduced by the 14F head (-1 is reproduced using the pilot signal).
It is suitable for application to an information recording device using an automatic track following method (hereinafter referred to as the A'I'F method) in which the RADR is dragged to each track.

[Back station technique and its problems]

In this case, σ)1+' (An example of the recording nail device 1'1 is a video tape recorder (VTR). In addition to forming video tracks on the magnetic tape as a recording medium by means of an IY11 rotary head, each video track is recorded and recorded based on the current running speed of the tape in order to play back correctly. The servo has been devised, so you can rest assured that the basic information is an electrical running detection signal that correctly corresponds to the tape's current playback running speed.

Conventionally, as a method of borrowing the detection output proportional to the tape running speed, there is a detection output of = W in the tape running direction (for example, 6
A control signal (CTL signal) consisting of a timing signal recorded at a frequency of 1000 Hz (Chzl)) is reproduced by a dedicated fixed control signal set head (CTL head), and by counting the reproduction timing signal 'fr-, a tape running number detection signal is obtained. 14) is used.

This #jllnU signal head detection signal is originally used to track the playback head to each video track, and this detection signal is used as a dragging phase detection signal 7 to track the capstan using the difference signal from the reference signal. A control signal tracking method (CTL method) for performing servo is used.

However, this tape running speed detection printing is based on the ATF method's V'
l'RK is not applicable. The "ATF" method records pilot signals of different frequencies, for example 411, on a tape cyclically for each video track.
4 '75 (During IJ operation, pilots M' of trucks that come into contact with each other momentarily come into contact with each other, and by detecting the arrival of each pilot signal, a tracking error signal f is obtained, and this tracking error signal V is used to perform tracking servo. Therefore, since a timing signal is not recorded in the lengthwise direction of the tape in the chip 1 of this method, it is not possible to obtain a detection output corresponding to the tape running speed inscribed from the tape.

[Purpose of Light 1. January] The present invention was made taking all of the above points into consideration, and the ATF
The present invention proposes a recording medium running detection device that can output a detection output corresponding to the tape running speed based on the pilot signal recorded on each track of the recording medium in the recording medium. It is something.

In order to achieve this object, the present invention provides the following features: When the recording medium travels at a speed that is different by (1) from the traveling speed at the time of recording the pilot signal, the recording head can track the number of sheets. By using the fact that the level of the error signal of the tracking control till device undulates in the vertical direction by passing across the tape 7', the tape speed detection output '(r') corresponds to the running speed of the track 7'.
) is a thing.

〔Example〕

Regarding the drawings below, two heads of the present invention fA'l'F system -
Let's discuss in detail what would happen if a helical traveling type VTRK were used.

First, with reference to Figures 1 to 3, the principle of I-cutting of the ATF type tracking +H wholesaler tT will be described. In other words, this tracking control fa4I device light is the first one to output the playback output of the rotating video head as a playback head by using a low-pass filter configuration σ) Pilot H, If detection circuit (1) In response to this, a reproduced pilot signal S2 is created using the endogenous output of the pilot signal recorded on a magnetic tape as a recording medium, and this reproduced pilot signal S2'? Error signal carving circuit (3)
give to The tracking error signal 83 formed under the error signal forming circuit m (a+ is the control side of the lock point control circuit (4)) is sent out.

On the tape 5, as shown in Fig. W2, there are a number of drums having different numbers of drums, for example, four unique pilot signals f, , f2 .
r3. A set of four video tracks TI, T2, T3, and T4, on which f4 is recorded, are formed diagonally and closely together so as to repeat in a copper-like fashion.

Here, the effective 1Iv18 of the video head constituting the playback head (6) is selected, for example, to be approximately equal to the width of the tracks T1 to T4. is correctly tracking the track that is currently being played back and scanned (this is called the raw track), 'F:V: Nail ζ
By reproducing only the 10 bits that are being played, the pilot frequency component included in the reproduced power is 1.
seed #1, and on the other hand, when the playback head (6) is in the right-shift rL or left-shift state with respect to the track as shown by the (& line), the right t(11 or Since the pilot signal sound recorded on the track adjacent to the left 11th is also generated, the pilot frequency component included in the raw output becomes unique, and the magnitude of the valley pilot frequency component is also increased. is set to have a size corresponding to 111 the same length of the PL head facing the corresponding track.

Frequencies f1 to f4 of Pilot No. 48 f1 to f4 of Runi 4 Progress Class are low frequency wave numbers (600 to 700 CkHz
)) is selected for the lower band of the color component converted to ).
, km, among the four tracks T1 to T4, for example, centering on the odd-numbered tracks TI and T3 (-, the frequency difference with the pilot signal of the right track is ΔfA, and the frequency F with the pilot signal of the left 111++ track)
Tracks T2 and T4 of even numbers are arranged so that Δf)l is reached. The frequency with the pilot signal of the track 1 on the right side of the center is IA'ΔfB, and the number of laps with the pilot signal of the track 11411 on the left is ΔfA. Therefore, the head (6) When the odd-numbered tracks 'L'1.'L'3 are being reproduced, there is a signal component with a numerical difference Δf6 from the seed θ as a frequency component of the pilot signal included in the raw signal, and the head ( 6) is found to be in a right-shifted state,
Also, if there is a signal component with a circumferential θ branch difference of ΔfB, the head (6
) is in the left-right state, and it can be seen that tracking is correct when there is no signal component with a frequency difference of ΔfA and ΔfB in ζ and others.

Similarly, when the head (6) is reproducing the second even-numbered track T2°T4, as the frequency component of the pilot signal included in the reproduced signal) I! If there is a signal component whose frequency difference is Δt゛ゎ, it is known that the head (6) is in the right-shifted state, and if there is a signal component with a frequency difference of ΔfA, then the head (6) is in the left-shifted state. I understand something.

In this embodiment, the first. Second. Third. Tracks Tl, 'I'2, T3, and T4 of board 4 are allotted to t'1. fr, ) i'il M number f1. f2.
f3. f4i [f1=1020 bodies].

f2=116 C1cllz: ] , f3=160 (
1 (+12), f4-146 (kllz) selected n
1 Therefore, for the difference frequency ΔfA and Δf, ΔfA”lfl
121=mouth, -f, +1=j4[kilz)...-
...... (11 ΔfB-mouth.-+31 = 1t1-+41 =44(
kllz3・・・・・・・・・・・・ (2) Selected.

From He-Rad (6)! The n raw signal s1 with such content is passed through a low-pass filter +l = 511'
The pilot signals r, ~f4 included in the reproduced signal S1 are taken out, and the blind raw pilot signal S2 is sent to the multiplier (14).
)+=5-1 multiplication input.扛１calculator (
14) is connected to the lock point control circuit (4) as a second calculation input.
) is given as a reference signal S11.

Lock point control 1-ro path (4) is 444 with circumference M number f, ~ f4
A pilot frequency generating circuit (16) that generates pilot frequency outputs f1 to f4f of j, and a rotating drum (not shown) K are connected to a rotary drum (not shown). The head switch circuit (17) receives the head switching pulse RF-8W (Fig. II3A) for changing the level. In this embodiment, the switch circuit (17) is a head switching pulse RF-8W.
It has a quaternary caritter circuit that performs a counting operation every time the level of
The gate signals corresponding to the fourth tracks 'r1 to T4 are set to 1.
Let's repeat 1M times, this track T1~T
The gate f is opened by the gate signal of 4 and the pilot frequency generation circuit (3rd EQ+B) is opened.
16) Sequentially send out the wave number outputs f1 to f4 as the reference pilot signal 811,
ing.

Note that the reference pilot output 811 obtained at the output end of this switch circuit [17] is sent to the video head as a pilot signal via the signal line (18) during recording. Truck T1
~Frequency f1 corresponding to 1111 scanning T4~
The pilot signal 'fr of f4 is sequentially applied to the video head for recording on each track T1 to T4.

In this way, the head ((i) or tR1~Tdj 4
4'i-th σ) The corresponding +II raw track; CIU, Reference pilot signal 81 that lights up
．． 1 to #I, when there is a tracking error, the reproduction pilot signal S2 contains the subtraction T1. The output 812 is obtained by operating the difference 1M number of drums LM, which has a frequency equal to the difference between the filter frequency component and the reference pilot signal Sll. g11σ
) may also include other signal components such as frequency components). This multiplication U4 force 812 is composed of a band-pass filter,
)) Ruby (21) given i, 4). Hitoshi], 1's difference frequency detection circuit (additional) is by Koushi.

When the output 812 contains a signal component with a difference frequency ΔfA based on the above-mentioned equation (1), it is extracted, rectified, and converted into blood flow by the DC conversion circuit (22) of the circuit structure hv. 1o
The first error number 3 813 at the flow level is A4.

Similarly, the second difference frequency detection circuit (21) outputs the difference frequency Δ based on the equation (2) described above to the output SI2.
The 11 components of fB are included, and the various parts j are extracted and 1
The error detection signal S14 of ire 2 is obtained from the I-4 flow 1ψ1 path (E).

Here head (6) or culvert 1. Second. Third. When scanning the fourth track TI, T2, T3, T4 (therefore the switch +r:l+ path (17)
As shown in Figure B, each track Tl, 'J'2, T
3. At the timing corresponding to T4, frequency 0 becomes fl,
f2. f3. f4 reference pilot signal S11'+
If the transmission is shifted to the right, the endogenous pattern signal S2 obtained based on the reproduction signal S1 of the head (6) will have frequencies f1 and f2 . as shown in FIG. 3C1. f2B/
Bi f3, 13 people f4. Pilot No. 48 of i'4 and fl will be included in 7'L! l11 output 8
μm shown in the third section IDI as 12 < the difference frequency needle Δ
fA (=f, ~f2), ΔfB (=f2~f3).

A signal tone containing ΔfA (=f3 to f4) and ΔfB (=f4 to f, ) is generated in Ilk. In contrast, the head (
6) is shifted to the left, the regenerated pilot signal S2 becomes as shown in FIG.
fl and f2. f2 and f3 ” 3 people f4σ) now includes the pilot signal, and depending on this, the multiplication output 8
12 is the difference frequency θΔfB(-f4
~f1).

ΔfA (=f, ~f2), Δtransport (=f2~f3), ΔI
A(=f3-f4)till' includes the first order.

Thus, as shown in FIG. 3 IE and F (for example, right
, state), the IIM 6fr level rises from 0 each time the head (6) scans a track.
The second error detection signal 813 and S14 can be received from the DC converting circuit (22) and (23).

As shown in the 3rd NG, by adding the input to the 4th path (2, 1) of 1st and 2nd error detection/numbers 813 and 814 as input and subtraction input. Every time the first and second error detection signals 813 and S14 are obtained alternately, a subtracted output S15 that changes in an alternating fashion is obtained. This subtraction output S15 is applied to the first input terminal a1 of the direct changeover switch circuit (25), and the polarity is reversed at the reversal port 'R'r (2+7), and the second
It is applied to input terminal a2. For example, the changeover switch circuit (2)) switches the head (
6) is scanning the odd-numbered track 'l''l, T3, the first input terminal al (+111) is switched to scan the even-numbered track 1'2.T4? When the head (6) is in the right-n state as shown in FIG. , a level output 816 is obtained (this TLK statement: [DC level 1 when the shift is to the left]) The force S16 has a magnitude corresponding to the amount of shift to the left (r) and has a negative polarity. If the head (6) is shifted to the right, for example, if the head (6) is shifted to the right, the double track will be the odd-numbered TI, T
3, the output terminal of the ridge calculating circuit (14) has the difference number of circumferences Δf.
When the signal component A appears, the output from the first difference frequency detection circuit (addition) side is given to the subtraction circuit (24), and at this time, the changeover switch circuit (25) is set to gt41.
σ) Since it is connected to the input terminal a i (41j), it sends out the error signal S17'f of the positive m1 group level.In response to the stiffness, the endogenous transistors 2 and even numbered T2, T4
When the outputs i and i of the first circuit (14) are the difference I
The second difference Naozawa ship due to the appearance of Hakuyanru y of Qihong Δf5! 1011 Shu (21) I111jρ・et al.
``Power is applied to one circuit (24) where power is destroyed. At this time, changeover switch circuit (``L5'') k, T '42's input terminal a2i111 is switched to 111, so wave leopard circuit ('2 .1) is inverted, its polarity is inverted in circuit (2+i), and sent as a positive DC level error signal S3.

Error signal S3f For example, when the correction signal is applied to the 411 servo circuit of the capstanzer revolver [7 is used as a positive value], the running speed of Q7'' is set to full speed up [2, when it is negative, it is slowed down] By correcting the sleeves, you can correct the phase shift between the video head and the Heigo track, and use the correct tracking servo.

The present invention provides a tracking error signal 83VC obtained from an ATli' type tracking device having the above principle configuration.
focuses on the fact that when the running speed of the recording medium during curvature differs from the running speed during recording, waviness with a similar period occurs due to the speed difference, and the number of waviness cycles is counted from the tracking error signal. Based on this counting result, the running detection signal 7
The recording medium running detection device θ is set as the original PI.
f configure.

In other words, right now! Video tracks T1 to T4 (TJI to T 14) recorded diagonally on a1 as shown in 41ZIAK
, T21~T271......), frequency 5!
The pilot signals of f1 to f4 are sequentially and cyclically recorded n7
If the tape as a recording medium is fast-forwarded in the direction of arrow v1 (to the right) in Figure 4A in fast-forward mode, the playback head will move diagonally upward from the lower edge of the tape.
While scanning a distance C corresponding to the video width Ka), the left track passes through the playback head position and traverses to the right. Incidentally, if the tape is run at a tape speed of +14 at which tracks T1 to T4 are recorded, the head will scan along the extending direction of tracks T1 to T4 as shown by ladle number II, whereas in fast forward mode Since the running speed & of the tape becomes faster than that during recording, a number of tracks corresponding to this faster speed are cut to '4i' in the 111 order of T1→T2→T3→T4.

If the scooping head crosses n tracks while scanning a distance #+1 corresponding to the length of one field, it means that the tape is fast-forwarding at n times the speed. . 1 However, one of the two rotating heads finishes scanning f for one field, and the end of the upper edge of the video width is 7ΦL (
I. When the other head is positioned below the video width i1 (: one track to the left at the edge) (++! This position is the starting point M (M,, M2...
) and start a new scan. Therefore, when the tape is running at n times the speed (7), the playback head starts scanning from the starting point jν1, and after crossing n tracks in the groove leading to the ending point, it moves from the ending point to the next starting point. To skip to M, one track will be used every 14+*.

If we express the above 641 relative movements between the head and the track as the head moving 4rt on a fixed track pattern, the head moves from the starting point IVI (Δ41. M2
), the trajectory fjh shown on the real axis of the AA 41 Nu IA reaches the end point L (Ll・+2...), and it passes through the entire trajectory shown by the dashed line to the next starting point M ( 1v12, M
3...). However, the number of tracks that the trajectory crosses during scanning (the number increases accordingly as the traveling speed of the J tape increases. In the 418th, the right t (o trajectory IVI, → L1 → 8・1□ 1 unit traveling speed At the slowest level, the head is at the start A of track TI3.
fv11 through T14'ie to T2] end point L1
Skip to the starting point M2 of T22 and turn left.
The +1-station playback head will follow approximately three tracks. The violet medium trajectory M2 → L2 → M3 is an example in which the tape moves a little faster, and the head moves from the starting point M2 of track 'r22 to T24 (through i7 to the end point L2 of T31). ' Skip to the starting point of 32 tvi 3 7'
In the end, I ended up passing 3.5 0) trucks.

Further left 1111 trajectory j, yt -+i, -+
M is an example where the tape is faster, and the head moves from the starting point M3 of track T32 to T.
, J3→'I'34, and then skips to the starting point b14 of Shun T42, which reaches the end point L3 of T41, and ends up passing through about four tracks.

Therefore, in response to the timing at each point on the scanning trajectory of the head, a head switching signal RF is generated which switches each time the head reaches the starting point M and the ending point of each scan, as shown in FIG. 4B.
-8W as described above with reference to FIG.
When the reference pilot signal 511f switch circuit (17) shown in FIG. That is, as the head traverses the tracks T1 to T4 sequentially and cyclically as shown in the fourth section ID, the level of the tracking error signal S3 does not shift to the right, but instead undulates in a sinusoidal manner to the left.

For example, if the head is located at the starting point M1 of track T1;3 when switching from the reference pilot signal S+]1; ?+A, the output S12 of the multiplication circuit (14) is the difference in frequency θ and the number Δ.
The component of fB (= f 1 to f 4) increases, and the error signal S3 reaches its maximum value in the right direction. When the bale head starts to enter the next σ) track T22, the difference frequency ΔfA (= f, ~
As the component of f2) becomes thicker, the error coefficient S3 increases in the leftward direction, until the head reaches the track'.
When reaching the end point L1 of r2+, the next track T
Skip to the starting point M2 of 22. At this time, Q RF-8
~V is switched and the reference pilot signal 811 of the switch circuit (17) is switched to the river wave number f2, and the head is in a state where it has started to enter the next track T23.
Therefore, the output S12 of the output circuit (14) has a difference frequency Δf.
B (= f, , ~ f3) σy is included.

However, at this time, the changeover switch circuit (25) is an inverting circuit (
Since the tracking error signal S3 is switched to 2ti)Oll, the tracking error signal S3 shows the same state in the left direction as the state before switching. And the starting point M2 of this track T22
The position in the width direction is the end point L1 of the previous track T21.
Since the position in the width direction of the tracking error signal S3 is approximately N the same as that of the tracking error signal S3, the tracking error number 1M of the tracking error signal S3 is approximately equal before and after switching, and as a result, the undulation waveform of the tracking error signal S3 is the same as that of the track T22? Even if you skip it, it will be consecutive F1.
I will do it.

When the head moves along the skip trajectory and eventually coincides with track M, an error occurs (I number S3 becomes maximum in the left/j direction, and becomes smaller as it enters the next track T24) .Then the head moves to track T2.
4, the error signal S3 becomes 0, and then when the track T31 is entered, the output SI of the multiplication circuit (14)
2, a component of the difference frequency ΔfA (=f2 to f,) is generated, and therefore the error coefficient S3 increases in the rightward direction.

When the head eventually reaches the end point L2 of track T31, the head switching signal RF-8W switches (Fig. 4B).
As a result, the wave number of the reference pilot signal Sll of the switch circuit (1'C) is switched to f3 (Fig. 4C), and
The head skips to MdM3 of the next track T32. Therefore, the output S12 of the tN circuit (14) contains a component of the difference frequency ΔfB (=f3 to f2).

However, at this time, the non-inverting 11
111 end a1, the error signal S3 shows the same state 7f to the right as before the switching. And the width direction σ) position 1 of the starting point M3 of this track 'l'32
6' is almost the same as the position IH in the width direction of the end point L2 of the track T31 of Ail, so the undulation θ of the error signal S3
The '' shape will continue even if track 'l' 31i is skipped.

The following is the same stock, head is 11, primary track T32°T
If T34 and T41 match, the error coefficient S: the maximum value in the rightward shift direction, 0. The maximum I'r M= 0 direction becomes smaller on the left.

Waviness waveform fN44 quotient IA of error signal S3 in the fourth diagram
Compared to the track pattern of 1. As you can see,
In the undulating shape, the head changes one cycle by crossing four tracks while scanning the scanning locus shown in the figure, and the head changes one cycle each time it scans one field. When scanning is completed using two trunks, a skip is made to the starting point M.

Therefore, in principle, the tape run during fast forwarding is 'r-j * if
P+Number of tracks crossed by the raw head during scanning (tracking error (undulation of g No. S3) i! II ru ∥ ν multiplied by 4 ha, i, L) lalo) μ) track where the raw head crossed Number (circle 41: Head refueling field ship, that is, the rising part and falling part 9 of the head switching pulse RF-8W)
It is found as the vinegar of n, r), and it is ft-1 + #, and -CH is added.'f! Ru.

1Makage Q:L Tracking error signal M during fast forwarding
As mentioned above about the beginning of the S3 undulation, when rewinding, you can similarly know the running speed of the tape based on the number of tracks crossed by the strongyle.

Therefore, in this case, if the Dangyu head crosses n tracks on the IELL, which is scanning a long flute that corresponds to one field's long flute, the tape will be played at -(n-:'') times the speed. (Rewind) (also known as ZEN-NOYO, Sutaka).

In other words, 2.51XI A corresponding to Fig. 4 A~1]
As shown in ~D, since the tape is fed in the opposite direction to that in the case of straight forwarding as shown by the arrow v2, the internal head moves all tracks T4→T3→゛■゛2→1゛1. Cut into 11111 pieces in the direction and ladle. Therefore, by scanning the head in the same direction as the arrow ① in Fig. 4, the playback head can be moved from the starting point M of the video width to the final point I, and the signal σ) on the track C is shown. Scan the trajectory 1. Go.

Therefore, in the case of fast forwarding and turning the switch to 7, turn the switch (1
7) to It, reference pilot signal 8 of l drum pf1
11 in the right gill 71 (Fig. 5 IC), P)
The raw head moves from the starting point M5 of track T43 to the scanning axis 1
・Along track 'I'42→T41→'l'34→
T3; (pass through fiQ to reach the end point L5 of track T32
While running in a trench (FIG. 5A), the tracking error signal S3 undulates in a sinusoidal manner Pk to the left and right (Igl)). Similarly, the frequency f2. 1■ in the state where the reference pilot signal Sll of f3... is given n]
Raw head causes M6. From M7... to the end point L6.
Until scanning the locus L7..., the dragging error signal S3 continuously undulates in a sinusoidal manner from leftward to rightward.

However, if this happens, the frequency of the reference pilot signal 811 changes from fl to f2. When switching from f2 to f3... song,
A long point L51L6. L7......k
A Jv16. Skip one track to M7, M8... 7D 51sl Compare the undulation wave of the tracking error signal S3 of D with the track turn of ff7A5 and IA. There is =
By completing four trunks in 1, there is a change of 1 lap, and the head runs once every time the head runs for 1 field.

If there is no track, the scan will skip from the end AL of scanning to the starting point M by using one track ftj times, and will scan this (7') track by unpacking it.

Therefore, the running quality of the tape when rewinding IyA is the number of tracks (tracking error signal S3σ) when the internal head is rewinding (tracking error signal S3σ). The number of tracks skipped (n, which is calculated as the number of running iL fields of the head, that is, the number of rising and falling parts of the head LJJ pulse RF''-SW) can be expressed as a reduced value.

More than! II] The tape made by FIF - speed -
The detection device can be configured as shown in FIG. In Figure 6, (31) is an ATI'' type tracking control device, which has the same configuration as the structure b! in Figure 1. Therefore, parts corresponding to No. 1171 are designated by the same reference numerals. If the tracking error signal S3 has a positive feedback loop, the undulation of the Schmitt amplifier structure is given to the output circuit (32). 't++ rising detection pulse S5) is generated for each hour-shaped period.

This detection pulse S5 is applied to the display circuit (33), and the number of detection pulses S-5 is cumulatively counted.

On the other hand, the head UHA pulse RF-8W mentioned above with reference to FIGS. A fast-forward/rewind command signal S7 generated at a timer (not shown) is given as an operation mode signal. The arithmetic circuit (33) cumulatively counts the skip number signal S6, and when the fast forward/rewind command number S7 is in the fast forward mode, the cumulative count of the number of undulating period detection pulses S5 is directly counted by the skip number signal S6. Add the cumulative division value of , and fast-forward the results of this addition)
Send 111 as content 1 S8. ′
f Also, when the fast forward/rewind command signal S7 is in the spring rewind mode, the skip circuit (33'l ir, 1 swell cycle #!j
, reduce the cumulative fj:iMl' h value of S6 from the yarn phase count of pole-out Barne S5]+"+ and set the cumulative fj:iMl' h value of No. Sends out as a running detection signal.

In the configuration shown in FIG.
, a fast forward/rewind command signal S7 is given to the performance circuit (33)K. -1.1 for force swell
The nail detection circuit Cl2) detects the tracking error signal S3 once every time the playback head cuts and scans one of the four racks of cedar in both the fast forward mode and the rewind mode.
(Using the fact that lj worth of undulation has occurred [7, so θ) 4
'9. ! The output pulse S5 is sent to an arithmetic circuit (33), and the number of 8B waveforms is calculated. Play head here
Since the number of tracks crossed during 4-square blue is (number of waviness cycles x 4), the content of the take that is counted by 1g to the arithmetic circuit (33) is /2Vc of the number of tracks crossed by the Naoki head during scanning. profit] hit.

The skip count signal s6 is the number of times the skip is 1.
The number of skips that actually occurred in M(3-+') is counted down, and the cumulative learning is done in the performance circuit (:<:3). Incidentally, as described above in FIGS. 4 and 5, when switching the skip head of the reproducing head, the head switching signal RF'-8 to Vσ) is generated in the rising and falling order, whereas this head switching signal rtl
If L'-sw is divided by 4, the rising and falling intervals of the resulting pulse signal will be expanded by 4 times, and therefore the string pulling count value of the performance circuit c33) will be counted down to reach n.

The force/combination calculation circuit (33) adds or subtracts the value of 4, which is the number of tracks skipped by the playback head, from the value of 4, which is the number of tracks that the playback head traversed during scanning, in the fast forward mode or the rewind mode. By doing this, we actually receive a running detection signal whose content is proportional to the number of tracks in the head f: JFiJ, which corresponds to the number of tracks, in other words, the length of the tape. F88: You can bring it out.

If configured as shown in Figure 6, the running speed of Qi-Two will be 5. , (, the running detection signal can be transmitted, and thus the ATT one-type tracking control device C(l'
Tracking error signal 83? By using it, you can add a new iJl] easy grace to the next door.

In addition, in the embodiment shown in FIG.
32) As positive 4Mm loop 't% Schmidt cycle I1
Although we have described the case where a circuit is used, the same effect can be obtained by using a Threnjord circuit instead of this circuit.

A phase-locked roof (PLL) circuit configuration σ) is used as the undulation cycle number detection circuit (32), and the arithmetic circuit (32) is
3) may be given. V) In this case, when the tape is fed or rewound completely, the rotating head will cut out.
Due to M, etc., a part of the undulating waveform of the tracking error signal 83 is missed, and the running detection signal S8 is detected by M↓, which can avoid the cow slop 71 by making a sound.

Incidentally, the 4q7-minute effect of the rono filter provided in the PLL Roof Riichi Naiyoku 1) creates a so-called flywheel effect, so there is considerable waveform distortion in the undulating drum-shaped -H1' of the tracking error light No. 1 S3. Even if there is a difference, the angle can be supplemented, and therefore a situation where the undulation group period number detection circuit (32) cannot exceed the ten-protrusion level can be prevented from occurring.

[Y[4, Example of use] The above recording medium running detection AA position is applied to the automatic tape adjustment device that automatically adjusts the tape speed at the time of recording to the tape speed at the time of full recording. Nru. For example, in an NTSC VTR capable of normal recording (SP mode) and long-term recording (LP mode), the tape retrieval ratio when recording in each mode is set to 2=1. In this case, tape 7 was nailed to B in fast SP mode.
If the 1r speed is re-elected in the slow LP mode, the undulation frequency of the tracking error signal S3 will be 7.5CI+7. ．． 1
Is this a tape recorded in LP mode? SJ-
In 'mode, I'l cow sun, ge15C [(z,) completes.

A mode switching signal S9 (car 6121
If you send out a foreshadowing of 1 min 1 vol), you can realize the 4I Shouji 1 mountain training device 1■.

[Effect between lights]

According to the present invention, 1. For example, when the media is running at a different running speed than the one at the time of recording, the ATF is
It is possible to reliably use the tape running detection signal corresponding to the running speed of the naan of the old school samurai based on the Ut-ri generated in the tracking control signal of the system.

Therefore, when the full head is sent in the forward direction during internal play, the number of tracks skipped by the playback head is multiplied by 6, and the value of C1 is added to the value of C1 for the number of tracks the full play head crosses when moving. Maki sent in the opposite direction again!・By combining the humidity, the temperature of 413 degrees ~】I run 900 degrees F
You can get it.

Also, PL is used as t2 period tf Σ output circuit (:12)
L, using the one with the circuit configuration, if the tracking error sacrum S3 is damaged or missing (if there is a shrine, the sleeve 114 will be removed).

1zILtf1σ) Tlrko? '-1: Shukumei Figure 1 is the A T li' method of tracking thll project 11
A block diagram showing the principle of construction of device 1, Figure 2 is
Figure 3 is a diagram showing the 12 track patterns recorded on the top; Figure 3 is a waveform diagram showing the signal at the first valley; Figures 4 and 5 are for explaining the principle of the present invention. Track pattern σ) Simplified section 1 and signal temporary icing [')'l Figure 6 is a block diagram illustrating the recording medium h% presence detection device according to the present invention.

(1)...Pilot signal detection circuit, (3)...Error (K number formation circuit, (4)...Lock point control circuit,
(14)...Multiplier circuit, (1b)...Generation circuit that extracts pilot frequency, (17)...Switch circuit, (2kl
'l, , (2]'l... 1st. 2nd difference frequency forest detection a1 circuit, (zz), (ZS)... Blood flow circuit, (
(See)...Switching switch circuit, (2I))--Inversion 1i'l path, (32)...JtFiγi+pu-out circuit, (3'J)...performance circuit, $1)...]/4 frequency divider circuit.

3

Claims (1)

[Claims] 1. A pilot signal having a frequency σ) of 14 grains is cyclically distributed in each track. σ) The difference frequency bIt numerator of the reproducing pilot signal included in the P) raw output of the reproducing head, and this difference frequency δν number multiplied by 'x' PC
↓t1, the tracking error signal for the dragging position σ) In the tracking tllll ji, jl binding, the output corresponding to the undulation of the tracking error signal is
Based on the output of the undulation period & l output circuit to obtain ff, and the output of the undulation detection circuit, the ladle output (the side that sends g *, the rr!+ path) corresponding to the running speed of the recording medium is In the first running mode, the recording medium L1 is specially designed to carry out an output of the above-mentioned υ cycle. 3. The above-mentioned rotational circuit is upward +iT: j The recording medium runs in the entire reverse direction. 2. In the running mode of 2, when the playback head skips the track 7=t1, the output with the target as the inner edge is decreased by the number of beat cycles in the upward direction.Patent#?j The recording medium outgoing detection device described in Item 1 of the patent application No. 1711. 4. 1 itt of the patent AI'J, in which the above-mentioned undulation cycle output circuit is made into a 7-work, 1-circuit, horizontal b'lI circuit.
> 1ill Section 1 n] Recording Media Running Inspection 11
Device.