JP2551271B2 - Recording medium for digital signals - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention, for example, converts a video signal or an audio signal into a PCM signal, and reproduces a PCM signal recorded on a recording medium as a single diagonal track by a rotary head. The present invention relates to a digital signal recording medium suitable for use in.

[0002]

[Background Art and Problems] A helical scan type rotary head device is used to form and record one video track and one audio track per unit time on a magnetic tape and reproduce the recorded tracks. In this case, it is considered that the video signal and the audio signal are converted into PCM and recorded and reproduced. This is because high quality recording and reproduction can be performed by using PCM.

In this case, in the tracking control in which the rotary head correctly scans the recording track during reproduction, conventionally, a control signal recorded on one end side in the width direction of the tape by a fixed magnetic head is used. Reproduction is usually performed by the fixed head, and the reproduction control signal and the rotational phase of the rotary head have a constant phase relationship.

However, this method requires a fixed magnetic head for tracking control.

Providing such a fixed magnetic head causes inconveniences due to the mounting location of the recording / reproducing apparatus when it is desired to downsize the recording / reproducing apparatus.

Therefore, a method of performing tracking control of the rotary head by utilizing only the reproduction output of the rotary head for reproduction without using the fixed head has been previously proposed by the present applicant.

According to this method, the PCM signal is compressed on the time axis.
Since it is easy to expand, it is not necessary to record and reproduce the signal continuously in time like an analog signal, and therefore, the area is divided into one track and the PCM is divided.
This is done by paying attention to the fact that it is easy to record a signal and a signal separate from this.

That is, when a PCM signal is time-axis compressed and a plurality of rotary heads obliquely form a track on a recording medium without forming a guard band, the PCM signal is recorded in the longitudinal direction of each track. Independently, a plurality of tracking pilot signals are recorded as a recording area, and at the time of reproduction, the recording track is scanned by a rotary head whose scanning width is wider than the width of the track. The tracking output of the rotary head is controlled by the reproduction output of the pilot signal.

A signal serving as a reference for recording and reproducing the tracking pilot signal is a pulse of 30 Hz which indicates the rotational phase of the rotary head obtained in synchronization with the rotation of the rotary drive motor for the rotary head. Signal (P
G) is used.

However, when the PG signal is used as the detection position reference when the tracking pilot signal is reproduced even during reproduction as described above, the reference position of the PG signal is deviated due to mechanical change with time or temperature change of the apparatus. , It appears as a kind of steady-state amount (offset) of tracking error during reproduction.

For this reason, it becomes difficult to reproduce the tracking pilot signal and control the rotary head at the same timing as during reproduction and recording, and there is a disadvantage that compatibility between devices is not achieved.

Further, since the sampling pulse for obtaining the reproduction output of the tracking pilot signal is formed for one rotation period of the head with reference to the PG signal, the error amount increases in an integrated manner, so-called. There is an inconvenience that the position of the sampling pulse shifts due to the influence of jitter.

[0013]

SUMMARY OF THE INVENTION In view of the above, an object of the present invention is to reliably reproduce a tracking pilot signal and correctly control a rotary head without being affected by mechanical aging of the apparatus, temperature change, or jitter. It is intended to provide a recording medium of a digital signal capable of achieving compatibility between devices.

[0014]

SUMMARY OF THE INVENTION According to the present invention, a tracking pilot signal is recorded independently of the digital signal as a recording area in the longitudinal direction of a track on which a digital signal is recorded, and the frequencies are different and are the same in adjacent tracks. On the other hand, positioning signals having different recording lengths between tracks are repeatedly recorded for every predetermined number of tracks, so that the mechanical time-dependent change of the device, temperature change, or jitter is not affected at all. Therefore, the tracking pilot signal can be surely reproduced to perform tracking control of the rotary head, and compatibility between devices can be achieved.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to FIGS.

FIG. 1 shows a circuit configuration of a recording / reproducing apparatus to which the recording medium of this embodiment is applied. Here, a tracking pilot signal, a positioning signal and an erasing signal directly related to the present invention are recorded. However, only the circuit configuration for reproduction is shown, and the rotation configuration for recording and reproducing the recording information, for example, a PCM signal, is omitted.

In the figure, 1A and 1B are rotary heads,
Reference numeral 2 is a magnetic tape as a recording medium. Rotating head 1
A and 1B are equiangular intervals, that is, 1 as shown in FIG.
The drums 3 are arranged around the drum 3 at intervals of 80 degrees. On the other hand, the magnetic tape 2 is wound around the tape guide drum 3 over a narrower range of, for example, 90 degrees than the 180 degrees. Then, the rotary heads 1A and 1
B is rotated in the direction of arrow 4H at a rate of 30 rotations per second, and tape 2 is run at a predetermined speed in the direction shown by arrow 4T, and is applied onto magnetic tape 2 by rotary heads 1A and 1B. The oblique magnetic tracks 5A and 5B are formed in a so-called overwritten state, for example. That is, the width (scanning width) W of the head gap is made larger than the track width. In this case, the width direction of the gap between the heads 1A and 1B is set to be different from the direction orthogonal to the scanning direction. That is, the so-called azimuth angles are made different.

Then, there occurs a period in which the two rotary heads 1A and 1B are not in contact with the tape 2 (this is a period corresponding to an angular range of 90 degrees in this example), and this period is used. The apparatus can be simplified by adding redundant data during recording and by performing correction processing during reproduction.

Reference numeral 6 denotes an oscillator for generating a tracking pilot signal P. The pilot signal P has a frequency f ₀ of, for example, about 200 kHz and is recorded at a relatively high level. The frequency of the pilot signal P is preferably a frequency with a relatively small azimuth loss as long as the linearity of the tracking phase shift and the pilot reproduction output can be guaranteed. Further, 7 and 8 are positioning signals S for detecting the position of the pilot signal.
And T, which serve as erasing signals for the pilot signals, and which are used for erasing the pilot signals, and which are recorded on the previously recorded tape, later on and then recorded on the tape. It is also used when a new recording is performed while erasing the recorded track, because the recorded track does not always match the previously recorded track, and therefore it is necessary to delete the pilot signal previously recorded. Frequency f
₁ and f ₂ are, for example, 700 kHz and 500 kHz, respectively, which are practically separated from the frequency f _{0 of the} pilot signal. Also, the recording level is such that the pilot signal P can be practically erased.

Further, 9 is a oscillator for generating an erase signal E _0, the erase signal E ₀ is thereby pilot signal P and the positioning signal S, when overwriting T, which like the signal P It is preferable that the erasing rate of S and T is high, and the frequency f ₃ thereof is, for example, about 2 MHz.

Reference numerals 10, 11, 12 and 13 denote recording waveform generating circuits, which respond to an edge of a delay signal related to a pulse PG, which will be described later, for example, a falling edge, and the generating circuit 10 receives a pilot signal from an oscillator 6. A pilot signal P having a predetermined time t _P (t _p is a recording time of the pilot signal or the like) is generated in accordance with how many pilot signals P are inserted per track and in which arrangement, and the generation circuit 11,
12 and 13 indicate how many positioning signals S, T and erasing signal E ₀ per track are based on the positioning signals S, T and erasing signal E ₀ from the oscillators 7, 8 and 9, respectively. Positioning signals and erasing signals having a predetermined time are generated at predetermined intervals depending on whether they are inserted in an array. 14
Is an OR circuit that logically processes each output of the generation circuits 10 to 13.

Reference numeral 15 is a switch circuit for switching the rotary heads 1A and 1B, which is switched by a switching signal S ₁ (A in FIG. 4) from the timing signal generating circuit 16. The timing signal generating circuit 16 includes rotary heads 1A and 1B obtained in synchronization with the rotation of the rotary driving motor 18 for the rotary heads 1A and 1B from the pulse generator 17.
The pulse PG of 30 Hz indicating the rotation phase of is supplied. Further, in response to the pulse PG, a 30 Hz pulse from the timing signal generation circuit 16 is supplied to the phase servo circuit 19, and the rotation phase of the motor 18 is controlled by the servo output.

The pilot signal or the like from the switch circuit 15 which is switched by the switching signal S ₁ from the timing signal generating circuit 16 is amplified by the amplifier 19A or 19B and then is passed through the contact R side of the switch circuit 20A or 20B, respectively. It is supplied to the rotary head 1A or 1B and recorded on the magnetic tape 2. The switch circuits 20A and 20B are connected to the contact R side during recording and switched to the P side during reproduction.

The output signal S ₂ (D in FIG. 4) from the timing signal generating circuit 16 is supplied to the delay circuit 21,
Here, after a delay corresponding to the interval between the mounting positions of the rotary heads 1A and 1B and the pulse generator 17, etc., it is supplied to the recording timing generation circuits 22 to 25. Further, the switching signal S ₁ from the timing signal generating circuit 16 is frequency-divided by the frequency divider 21 ′ into a signal S ₄ (C in FIG. 4), which is supplied to the recording timing generating circuits 23 to 25. Then, in the recording timing generation circuits 22 to 25, a timing signal as a recording reference such as a pilot signal is formed.
The signal S ₃ delayed by the delay circuit 21 (E in FIG. 4)
The falling edge of is matched with the time when the first head contacts the tape during one rotation period.

The recording timing generator 22 is synchronized with the falling edge of the signal S ₃ in one half rotation period of half rotation periods e.g. head 1B of the head, from the falling edge of the signal S ₃ on the other half rotation period of the head Time T + (3/2) t
_{After a} delay of _P (T is a time corresponding to a half rotation period of the head), a signal S ₅ (F in FIG. 4) having a duration t _P is generated at a predetermined interval T ₁ . The recording timing generation circuit 23 delays the trailing edge of the signal S _{3 by} a time (3/2) t _p only at one half rotation period of the head, for example, the half rotation period of the head 1B, at a predetermined interval T ₁ , but, for example, A signal S ₆ (G in FIG. 4) having a duration of (1/2) t _P is generated in the odd-numbered period of the head rotation, and (1/4) t _P in the even-numbered period of the head rotation period. . The recording timing generation circuit 24 uses the head 1A for the other half rotation period of the head.
For a half rotation period of time, delayed by a time T from the trailing edge of the signal S ₃ , at a predetermined interval T ₁ , for example, in an odd number of head rotation periods, the duration is (1/2) t _p , and the head rotation period is In the even-numbered positions, the signals S ₇ (H in FIG. 4) each having a duration of (1/4) t _p are generated. In addition, the recording timing generation circuit 25, in the odd number of the head rotation period,
In one half rotation period of the head, a signal of time (1/2) t _p is generated at a predetermined interval T ₁ with a delay of the time t _p from the trailing edge of the signal S ₃ , and in the other half rotation period of the head. Signal S
A signal having a duration t _p is generated at a predetermined interval T ₁ with a delay of time T + (1/2) t _p from the trailing edge of ₃ and, on the other hand, in an even number of head rotation periods, one half of the head is rotated. only time than the falling edge of the signal S ₃ in the rotation period t _P is delayed, the time (1/4) at a distance of t _p is the duration of a pair of pulses (1/2) t _p and (3 / 4) A signal of t _p is generated at a predetermined interval T ₁ , delayed by a time T + (1/4) t _p from the trailing edge of the signal S ₃ in the other half rotation period of the head, and the duration (5 / 4) A signal of t _p is generated at a predetermined interval T ₁ (see I in FIG. 4).

Recording timing generation circuits 22, 23, 24
And signals S ₅ (F in FIG. 4) and S ₆ (FIG. 4).
G), signal S ₇ (H in FIG. 4) and signal S ₈ (I in FIG. 4) are recorded waveform generation circuits 10, 11, 12 and 13, respectively.
To the generators 6, 7,
8 and 9, respectively, the pilot signal P, the positioning signal S,
T and erase signal E ₀ are recorded waveform generation circuits 10, 11, 1
The combined signal S is output to the output side of the OR circuit 14 via 2 and 13.
₉ (J in FIG. 4).

26A and 26B are switch circuits 2 during reproduction.
Amplifiers to which reproduction outputs from the corresponding rotary heads 1A and 1B are supplied when 0A and 20B are switched to the contact P side, and outputs of these amplifiers 26A and 26B are supplied to a switch circuit 27. . The switch circuit 27 has a switching signal S of 30 Hz from the timing signal generating circuit 16.
_{By t} (A in FIG. 5), the half rotation period including the tape contact period of the head 1A and the half rotation period including the tape contact period of the head 1B are alternately switched as in the recording.

Reference numeral 28 denotes a narrow bandpass filter having a pass center frequency f ₀ for extracting only the pilot signal P from the reproduction output from the switch circuit 27, 29 denotes an envelope detection circuit for envelope detecting the output, Reference numeral 30 is a sampling and holding circuit for sampling and holding the output of the envelope detection circuit 29, 31 is a comparison circuit for comparing the outputs of the envelope detection circuit 29 and the sampling and holding circuit 30, for example, a differential amplifier, and 32 is a differential amplifier 31. Sampling and holding circuits for sampling and holding the comparison error signal from the above, the sampling and holding circuits 30 and 32 are substantially adjacent to the track currently being scanned during normal reproduction, as will be described later. Both ends of adjacent tracks Sampling the crosstalk of each pilot signal recorded on, it serves to hold. Then, the output of the sampling and holding circuit 32 is taken out to the output terminal 33 as a tracking control signal.

The sampling and holding circuits 30, 3 are also provided.
And a narrow band pass filter 34 having pass center frequencies f ₁ and f ₂ for extracting only the positioning signals S and T from the reproduction output on the output side of the switch circuit 27 in order to form the sampling pulse for 2 and the like. 35 are provided, and their outputs S ₁₀ (E in FIG. 5) and S ₁₁ (F in FIG. 5) are supplied to the comparator 37 as a waveform shaping circuit via the switch circuit 36. Like the switch circuit 27, the switch circuit 36 is switched by the 30 Hz switching signal S ₁ ′ from the timing signal generating circuit 16.

Reference numerals 38 and 39 denote sampling pulse generating circuits provided on the output side of the comparator 37. The sampling pulse generating circuit 38 synchronizes with the leading edge of the output of the comparator 37 and outputs the first sampling pulse SP. ₁ is generated, and a second sampling pulse SP ₂ is generated after a predetermined time t _p has elapsed since the sampling pulse SP ₁ was generated. These sampling pulses SP ₁ and SP ₂ are supplied to the sample hold circuits 30 and 32, respectively.

Next, the circuit operation of FIG. 1 will be described with reference to the signal waveforms of FIGS.

First, at the time of recording, the rotary heads 1A and 1B
The pulse PG from the pulse generator 17 indicating the rotation phase of
In response, the timing signal generating circuit 16 outputs D of FIG.
Signal S as shown in₂Is generated and this signal S₂Is delayed
It is delayed by the circuit 21 for a predetermined time, and
Is a signal S as shown in E of FIG.₃Is output. This belief
No. S₃Are the recording timing generation circuits 22 to 25 as described above.
To the output side of the recording timing generation circuit 22
The signal S as shown at F in FIG._FiveIs generated. Also thailand
Switching signal S from the minging signal generating circuit 16₁Is frequency divider 2
1'is supplied to the output side of the signal as shown in C of FIG.
No. S_FourIs obtained. This signal S_FourIs the recording timing
The recording timing generation circuit 2 is supplied to the circuits 23 to 25.
3 to 25 are signals S₃, S_FourIn response to
Signal S as shown in G to I of FIG. ₆~ S₈To occur.

The signals S ₅ , S ₆ , S ₇ and S ₈ are supplied to the recording waveform generating circuits 10, 11, 12 and 13, respectively, and the recording waveform generating circuit 10 synchronizes with the supplied signal S ₅ to generate an oscillator. The pilot signal P from 6 is passed for a predetermined time t _{p at} predetermined intervals as shown in F of FIG.
Further, the recording waveform generating circuit 11 is adapted to pass the positioning signal S from the generator 7 in synchronization with the supplied signal S ₆ for a predetermined time at predetermined intervals as shown in G of FIG. The generating circuit 8 synchronizes with the supplied signal S ₇ so as to pass the position finding signal S ₈ from the oscillator 8 for a predetermined time at predetermined intervals as shown by H in FIG.
Further, the recording waveform generating circuit 13 allows the erasing signal E ₀ from the generator 9 to pass for a predetermined time at predetermined intervals as shown in I of FIG. 4 in synchronization with the supplied signal S ₈ .

The output signals from the recording waveform generating circuits 10 to 13 are added by the OR circuit 14, and the signal S ₉ as shown by J in FIG. 4 is taken out at the output side.

At this time, for example, the head 1B is shown in FIG.
Considering the case where the track 5B ₁ in FIG. 4 is recorded (the first half t _B period in FIG. 4), the signal S _{5 in} F in FIG.
, The first and second pulses of pilot signals P _A1 and P _A2 , respectively, and the first and second pulses of signal S ₆ in G of FIG. 4 correspond to positioning signals S _A1 and S _A2 , respectively. The first and second pulses consisting of a pair of pulses of the signal S ₈ in I of FIG. 4 correspond to the erasing signals E ₀ adjacent to both sides of the position finding signals S _A1 and S _A2 , respectively. The signals corresponding to the array, namely P _A1 , E ₀ , S _A1 , E ₀ and P
The combined signal of _A2 , E ₀ , S _A2 and E ₀ is taken out to the output side of the OR circuit 14 for each group.

Considering, for example, that the head 1A is recording the track 5A ₂ in FIG. 3 (t _A period in the first half of FIG. 4), the first and second pulses of the signal S ₅ in F of FIG. 4 are considered. Correspond to pilot signals P _B3 and P _B4 , respectively, and the first and second pulses of signal S ₇ in H of FIG. 4 correspond to positioning signals T _B3 and T _B4 , respectively, and signal S _{8 in} I of FIG. The first and second pulses of the position detection signal T
_B3 and T _B4 correspond to an erasing signal E ₀ adjacent to one side respectively, and signals corresponding to the arrangement of these signals, that is, T _B3 ,
The combined signal of E ₀ , P _B3 and T _B4 , E ₀ , P _B4 is taken out to the output side of the OR circuit 14 for each group.

Further, for example, the head 1B may be replaced by the head shown in FIG.
Rack 5B₂Is recorded (t in the latter half of FIG. 4)._BTerm
, The signal S at F in FIG._FiveThe first and
The second pulse is the pilot signal P, respectively._A3And P_A4Corresponding to
Signal S at G in FIG. ₆The first and second pulses of
Positioning signal S respectively_A3And S_A4Corresponding to
S of signal to kick₈A first and a second pulse consisting of a pair of pulses of
Rusu is the positioning signal S_A3And S_A4On both sides of
Erasing signal E₀Corresponding to the array of each of these signals
Signal, ie P_A3, E₀. S_A3, E₀And P_A4,
E₀, S_A4, E₀The composite signal of each is ORed for each group
It is taken out on the output side of path 14.

Further, for example, the head 1A may be replaced by the head shown in FIG.
Rack 5A₃Is recorded (t in the latter half of FIG. 4)._ATerm
, The signal S at F in FIG._FiveThe first and
The second pulse is the pilot signal P, respectively._B5And P_B6Corresponding to
Signal S at H in FIG.₇The first and second pulses of
Positioning signal T respectively_B5And T_B6Corresponding to
Signal S₈The first and second pulses of the position detection signal T_B5
And T_B6Erasing signals E adjacent to one side₀Corresponding to
Signal corresponding to the arrangement of these signals, that is, T _B5,
E₀, P_B5And T_B6, E₀, P_B6The composite signals of
It will be taken out to the output side of the OR circuit 14 for each
You.

On the other hand, from the timing signal generation circuit 16
In response to the pulse PG from the pulse generator 17.
Switching signal S as shown in A of FIG.₁Has occurred and this
Signal S ₁Is synchronized with the rotation of the rotary heads 1A and 1B.
As shown in FIGS. 4A and 4B, the signal S₁Is high level
Half rotation period t of the head_AHead 1A inside
Comes into contact with tape 2 and signal S₁Is a low level half a time
Conversion period t_BHead 1B abuts tape 2 inside
It is said to be related. Then, the switch circuit 15 switches
Signal S₁Due to period t_AThen, in the state of the figure, the period t_Bso
Are switched to the states opposite to those shown in the figure, and the head is turned off.
Replacement is done.

Accordingly, the signal S ₉ obtained at the output side of the OR circuit 14 passes through the R side of the amplifier 19B and the switch circuit 20B when the switch circuit 15 is in the state opposite to the state shown in the figure, and the head 1B at the beginning and end of the contact period of the head 1B with the tape 2 within the period t _B , as shown in FIG.
As shown in FIG. 7, recording areas A _T1 and A _T for tracking signals are provided at both longitudinal ends of the track 5B, which are equidistant from the center of the track 5B in the longitudinal direction.
_Each of _T2 has an odd number of head rotation periods (t in the first half of FIG. 4).
_In period _B ), time t _p + (1/2) t _p + (1/2) t
_p + (1/2) t _p and t _P + (1/2) t _p + (1 /
2) Recording is performed for t _p + (1/2) t _p , and at an even number of head rotation periods (t _B period in the latter half of FIG. 4), time t _p
+ (1/2) t _p + (1/4) t _p + (1/2) t _P and t _P + (1/2) t _p + (1/4) t _P + (1/2) t
Recorded during _P.

On the other hand, when the switch circuit 15 is in the state shown in the figure,
Signal S₉Is an amplifier 19A and a switch circuit 20
After being supplied to the head 1A through the R side of A, the period t_AInside
At the beginning and end of the contact period of the head 1A with the tape 2,
As shown in the figure, the center position of the track 5A in the longitudinal direction.
Both ends in the longitudinal direction of the track 5A, which are equidistant from
A recording area A similar to the above, which is provided in the portion_T1And A_T2To husband
Odd number of the rotation period of each head (t in the first half of FIG. 4)_ATerm
In (time), time (1/2) t_P+ T_P+ T_PAnd (1/2)
t_P+ T_P+ T_PRecorded during the even of the head rotation period
Number (t in the latter half of FIG. 4)_APeriod) time (1/4) t
_p+ (5/4) t_p+ T_pAnd (1/4) t _P+ (5 /
4) t_p+ T_PRecorded during.

Further, except for the time when the pilot signal, the position finding signal and the erasing signal are recorded, the audio PCM signal of one segment portion which should be recorded as one track, not shown, is generated in the period t _A. Amplifier 19A
It is supplied to the heads 1A through, amplifier 1 during the period t _B
Each track 5 is supplied to the head 1B through 9B.
It is recorded in a recording area A _P1 other than the recording areas of the pilot signals of A and 5B.

Next, reproduction of the signal recorded as described above will be described.

During this reproducing operation, the drum phase servo is applied to the motor 18 by the phase servo circuit 19 as in the recording operation.

The signals extracted from the tape 2 by the rotary heads 1A and 1B are respectively connected to the contact P side of the switch circuit 20A, the contact P side of the amplifier 26A and the switch circuit 20B, and the contact P side of the amplifier 26A and the switch circuit 20B and the amplifier. It is supplied to the switch circuit 27 via 26B. A half turn period t _A which comprises tape contact period of the switch circuit 27 is similar to the recording by 30Hz switching signal S ₁ 'as shown in A of FIG. 5 from the timing signal generating circuit 16 heads 1A, head It is switched alternately in the half rotation period t _B including the tape contact period of 1B. Therefore,
From the switch circuit 27, an intermittent PCM signal S _R for each segment as shown in FIG. 5C is obtained, which is demodulated to the original PCM signal supplied to the reproduction processor (not shown) and further decoded. The data for each block is detected by the block synchronization signal and subjected to processing such as error correction and de-interleaving, is converted into an analog audio signal by the D / A converter, and is output to the output side.

Tracking control is performed as follows.

Now, for example, the head 1B has one point in FIG.
Track 5B as shown by the dashed line₁Scan width W including
When scanning the range of
5B ₁5A on both sides of₂, 5A₁Straddle
Scan area A as shown in FIG._T1In the truck
5B₁Pilot signal P_A1And adjacent tracks 5A
₂Pilot signal P_B3And truck 5A₁Pyro's
Signal P_B1Play and area A_T2In Track 5
B₁Pilot signal P_A2And adjacent tracks 5A₂
Pilot signal P_B4And truck 5A₁Pilot of
Signal P_B2And play. At this time, from the switch circuit 27
The reproduction output of the head 1B of the₀Narrow band
Is supplied to the bandpass filter 28 of FIG.
As its output S_AOnly the pilot signal
And is supplied to the envelope detection circuit 29.
You.

Further, the output S of the switch circuit 27_REach
The passing center frequency is f₁And f₂Narrow band bandpass
It is supplied to the filters 34 and 35, and the output side thereof is shown in FIG.
Positioning signal S as shown in E and F of FIG._TenAnd S₁₁Gatori
Be kicked out. These signals S _TenAnd S₁₁Is a switch circuit
36, the switching signal S₁When ′ is low level,
No. S_TenIs taken out, and when it is at high level, the signal S₁₁Gatori
It is taken out and supplied to the comparator 37.

The comparator 37 supplies the supplied signals S ₁₀ and S
₁₁ is compared with the reference value to perform waveform shaping and supplied to the sampling pulse generation circuits 38 and 39. The sampling pulse generating circuit 38 coincides with the rising edge of the waveform-formed signal S ₁₀ to generate the first sampling pulse S as shown in G of FIG.
P ₁ is generated, and this sampling pulse SP ₁ is supplied to the sampling and holding circuit 30. At this time, as apparent from FIG. 5, the sampling pulse SP ₁ samples the crosstalk of the pilot signals P _B3 and P _B4 of the adjacent track 5A ₂ on the opposite side to the transfer direction indicated by the arrow 4T (FIG. 3). In this state, the sampled signal advances and the differential amplifier 3 is used as the tracking signal of the phase.
1 is supplied to one input terminal.

Further, after the time t _p from the generation of the sampling pulse SP ₁ , the adjacent track 5 on the tape transfer direction side is formed.
Crosstalk between the pilot signals P _B1 and P _B2 of A ₁ is supplied from the envelope detection circuit 29 to the other input end of the differential amplifier 31 as a tracking signal with a delay phase.
Therefore, the differential amplifier 31 outputs the pilot signals P _B3 and P _B1 ,
The tracking signals corresponding to the crosstalks of P _B4 and P _B2 are sequentially compared.

Then, the comparison error signal from the differential amplifier 31 is supplied to the sampling and holding circuit 32, where time t has passed since the sampling pulse SP ₁ was generated.
After _p , sampling is performed by the sampling pulse SP ₂ generated from the sampling pulse generation circuit 39.
Therefore, the difference between both inputs to the differential amplifier 31 is obtained as a tracking control signal from the sampling and holding circuit 32, and this is supplied to a capstan motor (not shown) from the output terminal 33 to control the tape transfer amount. , The level difference between both inputs to the differential amplifier 31 is zero, that is, when the head 1B scans the track 5B ₁ , it is controlled so as to straddle the _two tracks 5A ₂ and 5A ₁ on both sides by the same amount. . That is, the center position of the gap of the head 1B in the width direction is controlled so as to match the center position of the track 5B ₁ for scanning.

The same applies to other trucks.
Done, for example truck 5A₂Head 1A scans
When, track 5B on both sides₂And 5B₁The pie
Lot signal P_A3, P_A4And P_A1, P_A2Crosstalk
As these are obtained, sampling pulses are generated as above.
It is supplied from the circuit 38 to the sampling and holding circuit 30.
Sampling pulse SP₁By pilot signal
P_A3, P_A4Crosstalk is sampled and tracked
Signal and supplies it to the differential amplifier 31 in the next stage.
Together with pilot signal P_A1, P_A2Supports crosstalk
The output from the envelope detection circuit 29
Here, pilot signal P_A3And P_A1, P_A4And P _A2The cross
Compare the tracking signals corresponding to each talk,
The comparison error signal is supplied to the sampling and holding circuit 32.
Sampling pulse SP₂To sample at
To obtain a tracking control signal for the head 1A.
Can be

[0053] Further, when scanning the track 5B ₂ head 1B is in the same manner, as shown in FIG. 3, the track 5A ₃ and 5A ₂ of the two neighboring pilot signals P _B5,
Since the crosstalk between P _B6 and P _B3 , P _B4 is obtained, the cross talk between the pilot signals P _B5 and P _B6 is sampled by the sampling pulse SP ₁ , and the pilot signals P _B5 and P _B3 , P _B6 are sampled by the differential amplifier 31. and comparing the respective corresponding tracking signal to crosstalk P _B4, by sampling the comparison error signal finally sampling pulse SP _2, it is out to obtain a tracking control signal for the head 1B.

[0054] Further, when scanning the track 5A ₃ head 1A is in the same manner, as shown in FIG. 3, the track 5B ₃ and 5B ₂ of the two neighboring pilot signals P _A5,
Since the crosstalk between P _A6 and P _A3 , P _A4 is obtained, the cross talk between the pilot signals P _A5 and P _A6 is sampled by the sampling pulse SP ₁ , and the differential amplifier 31 uses the pilot signals P _A5 , P _A3 and P _A3 . _The tracking control signal for the head 1A can be obtained by controlling the tracking signals corresponding to the crosstalk between _A6 and P _A4 and finally sampling the comparison error signal with the sampling pulse SP ₂ .

FIG. 6 shows an example of a concrete circuit configuration of the sampling pulse generating circuit 39. In FIG.
Reference numeral 40 is a counter for counting the number of waves (pulses) of the position finding signal supplied from the comparator 37, 41 is the content of the position finding signal in response to the signals S ₄ , S ₁ ′, that is, the position finding signal in this embodiment. A data selector that selects four types of data (set values) classified by each frequency and recording length of S and T, and 42 is a match detection circuit that detects a match between the count value of the counter 40 and the data of the data selector 41. As the coincidence detection circuit 42, for example, a digital comparator is used.

Reference numerals 43 to 46 are delay circuits for generating a predetermined delay signal from the sampling pulse SP ₁ , and the counter 40 is enabled (energized) by the output of the delay circuit 44.
The output of the delay circuit 45 is cleared. Reference numeral 47 is a D-type flip-flop circuit. The output of the coincidence detection circuit 42 is supplied to the input terminal D of this flip-flop circuit 47, and its clock terminal C is supplied.
A sampling pulse SP ₁ is supplied to K through a delay circuit 46.
Is substantially applied, and the output of the delay circuit 45 is supplied to the reset terminal R thereof. Reference numeral 48 denotes a gate circuit, for example, an AND circuit. The output of the delay circuit 43 is supplied to one input terminal of the AND circuit 48, and the output of the output terminal Q of the flip-flop circuit 47 is supplied to the other input terminal. The sampling pulse SP ₂ is output from the output terminal.

Next, the circuit operation of FIG. 6 will be described with reference to the signal waveforms of FIG.

Now, when the comparator 37 supplies a signal S ₁₃ as a positioning signal as shown in D of FIG. 7 to the sampling pulse generating circuit 38, the sampling pulse generating circuit 38 outputs the first signal S ₁₃ of the signal S ₁₃ . A sampling pulse SP ₁ as shown by H in FIG. 7 is generated in synchronization with the rising edge of the pulse. The sampling pulse SP ₁ is supplied to the sampling hold circuit 30 (FIG. 1) described above and also to the delay circuits 43 to 46.

The delay circuit 44 uses the sampling pulse SP ₁
A signal S ₁₂ as shown in C of FIG. 7 having a duration of approximately (1/2) t _{p at} its output in synchronism with
This signal S ₁₂ is supplied to the counter 40 as an enable signal.

[0060] Counter 40 counts the pulses of the signal S ₁₃ from the high level period comparator 37 of the signal S _12.
On the other hand, the data selector 41 selects the data associated with the positioning signal in response to the signals S ₁ ′ and S ₄ shown in FIGS. 7A and 7B. When the selected data and the contents of the counter 40 match, the match detection circuit 42 outputs to the output side a signal S ₁₄ as shown by E in FIG. 7 which lasts for a predetermined time after the trailing edge of the final pulse of the signal S ₁₃ . And the signal S ₁₄ is supplied to the flip-flop circuit 47 as data.

The delay circuit 46 has a sampling pulse SP.
₁A predetermined time Δt in synchronization with ₁Later shown in Figure 7F
Signal S_FifteenGenerates this signal S_FifteenIs Flipf
Input to the clock terminal CK of the drop circuit 47
Signal S supplied to terminal D₁₄Is latched. Incidentally, late
Delay time Δt in the delay circuit 46₁Is t_P> Δt₁>
(T_P/ 2).

Further, the delay circuit 45 synchronizes with the sampling pulse SP ₁ and after a predetermined time Δt ₂ from this, G of FIG.
A signal S ₁₅ as shown in (1) is generated, and this signal S ₁₅ is supplied to the counter 40 to clear its contents and to the flip-flop circuit 40 to reset it.
As a result, a signal S ₁₇ as shown by I in FIG. 7 is generated at the output side of the flip-flop circuit 47. The delay time Delta] t ₂ in the delay circuit 47 is a Δt _2> t _p.

The delay circuit 43 generates a signal S ₁₈ as shown by J in FIG. 7 in synchronization with the sampling pulse SP ₁ and a predetermined time t _p thereafter, and this signal S ₁₈ is supplied to one of the AND circuits 48. It is supplied to the input terminal.

Since the signal S ₁₇ formed as described above is supplied to the other input terminal of the AND circuit 48, the AND circuit 48 opens the gate by using this signal S ₁₇ as a gate signal. A sampling pulse SP ₂ as shown by K in FIG. 7 is generated in response to the signal S ₁₈ . Then, the sampling pulse SP ₂ is supplied to the sampling hold circuit 32.

In this way, the sampling pulse SP
Can generate ₂

The sampling pulse SP ₂ can also be generated by processing of a microcomputer, not shown.

This will be described with reference to the flowchart of FIG.

When the playback mode is entered in step (a), the
Go to step (b) and check the positioning signals S and T here.
If not detected, the operation is repeated. Detected
And in step (c), the first
1 sampling pulse SP ₁And generate
The position detection signal S, T signal detection section
The wave number (pulse) Ni is measured.

Proceed to step (e) to determine whether the detected position finding signals S and T are the first ones generated in the reproduction mode. If they are the first ones, proceed to step (f). Interval of (1/2) t _p or (1/4) t
The section of _p is judged, and if either is satisfied, the second sampling pulse SP ₂ is generated in step (g). If the section of (1/2) t _p or the section of (1/4) t _P is not satisfied in step (f), it is not a position-finding signal and the process returns to step (b).

In step (e), if the position-finding signal has been generated for the second time and after in the reproduction mode, the process proceeds to step (h) to determine whether the polarity of the signal S ₄ has changed. . If the polarity of the signal S ₄ has changed, it is determined in step (i) whether the previous detection section was (1/2) t _p or (1/4) t _p , and (1)
If it is / 2) t _p , it is further judged in step (n) whether or not the current positioning signal is (1/4) t _p , and (1)
If it is / 4) t _P , since it is a true position finding signal, the second sampling pulse SP ₂ is generated in step ( _G ), and if it is not (¼) t _{p, the} process returns to step (B).

At the step (li), the previous detection section is (1 /
4) If t _p , proceed to step (l) to judge whether the current position finding signal is (1/2) t _p ,
If it is / 2) t _p , since it is a true positioning signal, a second sampling pulse SP ₂ is generated in step (g), and if it is not (1/2) t _{p, the} process returns to step (b).

FIG. 5 illustrates the steps (h) to (l).
It will be described in detail with reference to B, E and F of. In steps
For example, in the central portion of B of FIG._FourThe polarity of
When it is determined that the
Signal S shown at F of 5₁₁Of T_B4Is (1/2) t_pOr (1 /
4) t_pIs determined, and (1/2) t _p
Therefore, I will proceed to step (nu). And here Figure 5
Signal S shown in E_TenOf S_A3Is (1/4) t_pOr not
Judge whether or not (1/4) t_pBecause it is step (g)
Second sampling pulse SP at₂To occur.
Signal S at step (nu)_A3Is (1/4) t_POtherwise
Return to step (b).

Further, in step (ri), (1/4)
If it is t _P , it is judged that it is the signal T _B6 instead of the signal T _B4 of the signal S ₁₁ (therefore, the time when the polarity of the signal S ₄ changed is not the central portion of B of FIG. 5 but the right end portion thereof. S) of the signal S ₁₀ shown in E of FIG. 5 in step (e).
_Judge whether _A5 (not shown) is (1/2) t _P ,
Since it should be (1/2) t _P , the second sampling pulse SP ₂ is generated in step (g). If the signal S _A5 is not (1/2) t _{P in} step ( _l ), the process returns to step (b).

If the polarity of the signal S ₄ has not changed in step (h), the process proceeds to step (wo) to determine whether or not the detection section is the same as the previous positioning signal. In step (g), the second sampling pulse SP ₂ is generated. Referring to FIG. 5E, for example, the first S _A1 and the second S _A1 of the positioning signal S ₁₀
Since it is the same (1/2) t _p as the second S _A2 , the second sampling pulse SP ₂ is generated in step (g). Then, if the detection sections are not the same in step (wo), it is regarded as an erroneous detection, the first sampling state is held, and the process returns to step (b).

In this way, the second sampling pulse SP ₂ can be generated even by the processing by the microcomputer.

In the above-described embodiment, the rotary head device is a special one in which the tape is wound and recorded / reproduced over an angle range narrower than the head angle interval. Of course, the present invention can be applied to the case where a rotary head device for winding a tape is used.

[0077]

As described above, according to the present invention, when the recording track is scanned by the rotary head, a plurality of positioning signals having different frequencies in adjacent tracks and different recording lengths between the tracks for the same frequency. Is recorded for every predetermined number of tracks, a pulse signal for detecting this pilot signal is formed with reference to the starting ends of these position finding signals, and the tracking control signal based on the detected output is used to track the rotary head. By performing control, even if there is a mechanical change over time, temperature change, or jitter in the device, it will not be affected by any such effects, and tracking control can be performed accurately during playback, even when the device is different from that during recording. Therefore, compatibility between devices can be achieved.

Further, since the frequency of the position-finding signal is different between adjacent tracks, there is no influence of crosstalk and the setting range of the threshold level for detecting the position-finding signal can be widened. Further, since the recording lengths of the positioning signals are different between the adjacent tracks, it is possible to distinguish the adjacent tracks, and the positioning signal can be detected for a wide range of track deviations.

Further, since the positioning signal for detecting the position of the pilot for tracking control is recorded so as to have the starting end near the center of the adjacent pilot signal, the starting end is set near the center of the pilot signal. A circuit for delaying the position of the recording medium is unnecessary, and the circuit configuration of the apparatus using this recording medium is simplified accordingly.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an embodiment of the present invention.

FIG. 2 is a diagram showing an example of a rotary head device used in FIG.

FIG. 3 is a diagram showing an outline of a recording track pattern of the present invention.

FIG. 4 is a signal waveform diagram for explaining the recording operation in FIG.

5 is a signal waveform diagram for explaining a reproducing operation in FIG.

FIG. 6 is a circuit configuration diagram showing an example of a main part of the present invention.

7 is a signal waveform diagram for explaining the operation in FIG.

FIG. 8 is a flowchart for explaining an operation of generating a second sampling pulse.

[Explanation of Codes] 1A, 1B Rotating magnetic head 2 Magnetic tape 6 Oscillator for pilot signal 7 Oscillator for positioning signal 9 Oscillator for erasing signal 10, 11, 12, 13 Recording waveform generating circuit 21 Delay circuit 22, 23, 24 , 25 recording timing generation circuit 28, 34, 35 bandpass filter 29 envelope detection circuit 30, 32 sampling hold circuit 31 differential amplifier 36 switch circuit 37 comparator 38, 39 sampling pulse generation circuit

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Takashi Omori 6-735 Kita-Shinagawa, Shinagawa-ku, Tokyo Within Sony Corporation (72) Inventor Makoto Yamada 6-7-35 Kita-Shinagawa, Shinagawa-ku, Tokyo Within Sony Corporation (56) References JP-A-61-42768 (JP, A)

Claims (1)

(57) [Claims] 1. A with tracking pilot signal independently as a recording area and the digital signal in the longitudinal direction of the tracks the digital signal is recorded is recorded, different frequencies in the adjacent tracks and the same frequency of the next adjacent Positioning signals with different recording lengths between tracks are adjacent to each other 4
A recording medium for digital signals recorded repeatedly on each track .