JPS6150240A - Recording and reproducing device of digital signal - Google Patents

Abstract

PURPOSE:To reduce the effect due to the relation of position between a PG signal and a head and jitter of a drum at reproduction by interrupting a signal succeeding to a fixed pattern for a prescribed time so as to generate substantially a window signal from a PCM signal itself when the fixed pattern is discriminated in a signal recorded on each track. CONSTITUTION:When a 10 bit of the fixed pattern SYNC exists in a block B (the same in case of a block in a PCM data) of a sub code during the running on a track pattern A, a pulse signal SG is generated. Then a mask signal SM having prescribed width, e.g., a width for 360 bit's share is generated based on the pulse signal SG to mask the entire 360 bit. Then the parts of the sub code and the PCM data are masked completely by repeating the operation above at each block, mis-detection of it as a position signal to detect the position of a tracking pilot signal is avoided and it is not required to produce the window signal from the PG signal.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention converts, for example, a video signal or an audio signal into a PCM signal, and records this as one diagonal track on a recording medium by a rotating head in units of time. The present invention relates to a digital f-number recording and reproducing apparatus suitable for use when reproducing.

BACKGROUND TECHNOLOGY AND PROBLEMS A helical scan type rotary head device records video and audio signals on a magnetic tape once per unit time.
When recording by forming diagonal tracks one by one and reproducing them, it has been considered to record and reproduce video signals and audio signals by converting them into PCM. This is because if PCM is used, recording and reproduction of 81 quality is possible.

In this case, tracking control to ensure that the rotating head correctly scans the recording track during playback is as follows:
Conventionally, a control signal recorded on one end of the tape in the width direction by a fixed magnetic head is reproduced by the fixed head, and the reproduction control signal and the rotational phase of the rotary head have a constant phase relationship. This is what the trial court does.

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

Providing such a fixed magnetic head is inconvenient when it is desired to downsize the recording/reproducing apparatus due to the mounting location and the like.

Therefore, the present applicant previously proposed a method of controlling the tracking of a rotary head for reproduction by using only the reproduction output of the rotary head for reproduction without using this fixed head.

This method allows PCM signals to be easily compressed and expanded on the time axis, so the signal is
There is no need to record and play back temporally consecutively, so it is necessary to utilize the 60 range in one track and combine this PCM signal and a separate +11+1 signal. This was done with a focus on the fact that it can be done easily.

In other words, the time axis of the PCM signal is compressed and the track is forced diagonally by a rotating head of multiple fPJs.
When forming and recording on a recording medium without forming a command, a plurality of PCM pilot signals (for tracking independently as a recording area) are recorded in the longitudinal direction of each track, and during playback, Tracking of the rotary head is controlled by scanning width force (a recording track is scanned by a rotary head wider than the width of the track, and the reproduction ratio of pilot signals from tracks on both sides of the track being scanned by the rotary head) j .

The reference signal for recording and reproducing this drugging/Iirosoto (100th issue) is synchronized with the rotation of the motor for the rotation of the rotating head (the rotational phase of the rotating head). /</</response signal (P
G) is used.

However, when the PC signal is used as the detection position reference when reproducing the tracking pilot signal, the reference position of the PC signal may shift due to mechanical changes in the device over time, temperature changes, etc. It appears as a kind of steady amount (offset) of tracking error.

For this reason, it becomes difficult to reproduce the tracking pilot signal at the same timing as during reproduction and recording, and to control the rotary head, and there is a problem in particular that compatibility between devices becomes incompatible.

In addition, since the sampling pulse for obtaining the reproduced output of the tracking pilot signal is formed over the period of one rotation of the head based on the PC signal, the error increases in the form of integration, resulting in the effect of so-called jitter. As a result, the position of the sampling pulse may shift.

Therefore, the present applicant has also reliably reproduced the tracking pilot signal to control the rotating head correctly without being affected by mechanical aging, temperature changes, or shifters of the device, and to ensure compatibility between devices. We first provided a method for recording and reproducing digital signals that could be used to
9-11.630).

However, in this method, when detecting the positioning signal (synchronization signal) for detecting the position of the tracking signal, PCM data and subcode
Since the frequency of code) is close to Li, 1, there is a possibility that it will be mistakenly detected as a positioning signal.b
Therefore, it is necessary to provide a window.

However, the formant of the track that is actually recorded is, for example, a turn as shown in Figure 1A, where Margin, PLL, PosLAmb.
The frequencies of le are 4.7M1lz, and the frequencies of IBG are l and 5MIIz, both of which are 11- frequency signals, so the positioning signal included in the ATF area (
588kHz), there is almost no possibility of erroneously detecting βJ.

On the other hand, the frequencies of the Sub Code and PCM data also exist in the vicinity of the frequency of the positioning signal, and therefore both of them may cause false detection.

Sub Code, P CM data part actually consists of blocks as shown in Figure 1B, and 5
The 10 bits for YNC are fixed, and the remaining bits have various patterns depending on the location, music signal, etc. And Sub
In the case of Code, this block is repeated 8 times, and in the case of PCM data, this block is repeated 128 times.

Note that the numerical values in FIG. 1B represent the number of blocks occupied by each code.

In the method described above, the rotational phase of the rotary head obtained in synchronization with the rotary drive motor of the rotary head is
Since the wind signal is generated after a certain period of delay from the 011z pulse (hereinafter referred to as the PC signal), it is necessary to match the timing of the high level section of the wind signal and the detection section of the positioning signal, thus improving compatibility between devices. Considering this, it is necessary to suppress the positional relationship between the PC signal and the head, and the jitter of the drum during playback, within the allowable values, which is subject to limitations such as jitter margin and is also expensive.
There are disadvantages such as high price.

Purpose of the Invention The invention of B was made in view of the above-mentioned problems, and provides a digital Shingetsu recording and reproducing device that can substantially generate a wind signal from the PCM signal itself and eliminate the above-mentioned drawbacks. It is something to do.

Summary of the invention This invention compresses the time axis of digital (No. 3) and records diagonal tracks using a plurality of rotary heads without forming a force band on a recording medium. In a digital signal recording/reproducing device for reproducing a digital signal, a plurality of tracking pilot signals are recorded in the longitudinal direction of each track as a recording area independently of the digital signal, and a plurality of tracking pilot signals are recorded in the center of the pyro-node signal of an adjacent track. A plurality of positioning signals having a start end nearby and having a relatively high azimuth loss of 1.N frequencies are each recorded so that the recording time is at least 1 shorter than the recording time of the pilot signal, and during playback, the signals are scanned. The width of the recording track is 11 (wider than 1) of the recording track.
When scanning the track, the fixed pattern in the signal recorded on each track is determined, and if this fixed turn is determined, the signal following this fixed pattern is interrupted for a certain period of time, and the interruption period is A pulse signal is formed using the starting edge of the positioning signal as a reference, and during the period of this pulse signal, the pilot signal is detected from the relevant track that the rotary head is scanning, and this detection output is used to perform tracking of the rotary head. I'm trying to control it.

As a result, the wind signal is substantially generated from the PCM signal itself, and the influence of the positional relationship between the PC signal and the head and the jitter of the drum during re-travel can be reduced.

Embodiment First, the basic principle of this invention will be explained with reference to FIG.

In this invention, Sub Code and PCM data include:
As mentioned above, 10-bit 5YN is used as a fixed pattern.
Noting that there is a C Bakoon, while driving on the track pattern shown in Figure 2A, the S
ub Code block (not shown of course, but PC
If there are 10 bits of a fixed pattern of 5YNC (the same applies to a block of M data), one pulse signal SG is generated as shown in FIG. For example, as shown in the second diagram, a mask signal SM having a width of approximately 360 bits is generated, thereby substantially masking 360 bits (backward 350 bits) of the entire block.

By repeating this operation for each block, 5
The ubCode and PCM data portions are completely masked, and the remaining unmasked portion is a single frequency signal as described above, so it may be mistaken for a positioning signal for detecting the position of the tracking pilot signal. There is no need to perform detection, and there is no need to generate a wind signal from a PC signal as in the conventional method.

Hereinafter, one embodiment of the present invention will be explained based on FIGS. 3 to 8.

FIG. 3 shows the circuit configuration of this embodiment. In the figure, (18) and (IB) are rotary heads, and (2) is a magnetic tape as a recording medium. The rotating heads (IA) and (IB) are equiangularly spaced, i.e., as shown in FIG.
They are arranged around the periphery of the drum (3) at intervals of 180 degrees. On the other hand, the magnetic tape (2) is connected to the tape guide drum (
3) narrower than its 180 degree angular range around e.g. 90
Wraps over a range of degrees.

Then, the rotating heads (18) and (IB) rotate at 3 times per second.
The tape (2) is rotated in the direction of the arrow (411) at a rate of 0 rotations, and the tape (2) is run at a predetermined speed in the direction not shown by the arrow (4T), so that the rotating head (l^) and (IB)
As a result, one diagonal magnetic track (5A) (5B) as shown in FIG. 5 is formed on the magnetic tape (2), for example, in a so-called overwritten state.

That is, the head gap width (scanning width) W is made larger than the track width.

In this case, the width directions of the gaps of the heads (IA) and (IB) are set in different directions with respect to the direction orthogonal to the scanning direction. In other words, the so-called azimuth angles are made different.

In addition, in FIG. 5, only the ATF and PCM data areas are shown for convenience without corresponding to the track pattern of FIG. 1.

Then, there is a period (this is a period corresponding to an angular range of 90 degrees in this example) in which the two rotary heads CIA) (IB) of the 21st rigid do not come into contact with the tape (2), and this period is utilized. The apparatus can be simplified by adding redundant data during recording and performing correction processing during reproduction.

(6) is the tracking pilot signal Pt1 - generation 1
In this oscillator, the pilot signal P has, for example, a frequency fO at a value with a relatively large azimuth loss, a frequency at which the azimuth loss is effective, for example, about 2 kHz, and is recorded at a comparative fishing level.

Note that the frequency of this pilot signal P is preferably a frequency with relatively little azimuth loss, as long as the linearity of the tracking phase shift versus the pilot reproduction output can be guaranteed. Further, (6A) is an oscillator that generates a signal E for erasing the pilot signal, and the erasing signal E is later superimposed on the previously recorded tape while erasing the previously recorded information. This is used because when making a new recording, it is necessary to erase the previously recorded pilot signal because the recording track cannot always match the previous recording track, and its frequency f is: For example, 588, which is practically distant from the pilot signal frequency fo.
It is of the order of kHz, and is considered to be a frequency with a relatively large amount of azimuth loss. Further, the recording level is also set at a level that can practically erase the pilot signal P. and,
This erasing signal E is used in the present invention as a positioning signal for detecting the position of the pilot signal.

Further, (68) is an oscillator that generates an erasing signal Eo different from the above-mentioned erasing signal E, and this erasing signal Eo
As a result, the pilot/pilot signal P and the erasing signal E
When the signals P and E are overwritten, it is preferable that the erasure rate of these signals P and E is equal to each other, and the frequency f2 is, for example, 2M.
Hz is used.

(7), (7A) and (7B) are recording waveform generation circuits, and an edge detection circuit (8A
), (8B), the generating circuits (7) and (78) determine the number of pilots per track based on the pilot signals and cancellation signals from the oscillators (6) and (6B). Signal P and erasing signal E.

°C for a predetermined time Lp depending on the arrangement in which
(tp is each pilot signal and cancellation signal E.

However, the recording time per recording area of the erasing signal Eo is continuous for the time tp+ in track (5A).
) Rank (5B) uses the pilot signal P and erasure signal Eo having the time tp, which is the sum of the times at two separate locations, and the generation circuit (7B) uses the erasure signal E from the oscillator (6A). Based on this, erasing signals E having a predetermined time -tp are generated at predetermined intervals T1 depending on how many erasing signals E are inserted per track and in what arrangement.

(8F) is 1/3 of the occurrence (71, (78) and (7B)
) is an OR circuit that logically processes the output of (9) is a switch circuit for switching the rotating heads (IA) and (18), and is switched by the switching signal S1 (FIG. 6A) from the timing signal generating circuit 00.

This timing signal generation circuit u0 includes a pulse generator (
11) is supplied with a 30Hz pulse PC indicating the rotational phase of the rotary head (1Δ) (IB) obtained in synchronization with the rotation of the rotation base J motor (12) of the rotary head (1Δ) (IB). ing. Further, the pulse PG and a 30flz pulse from the timing signal generation circuit 0ψ are supplied to the phase servo circuit (13), and the rotational phase of the motor (12) is controlled by the servo output.

The pilot signal etc. from the switch circuit (9) switched by the switching signal S1 from the timing signal generation circuit 001 is amplified by the amplifier (14A) or (14B) and then sent to the switch circuit (15A) or (15B), respectively. It is supplied to the rotary head (IA) or (IB) via the contact R side and recorded on the magnetic tape (2). Switch circuit (
15Δ) and (15B) are connected to the R side during recording, and are switched to the P side during playback.

Also, the output signal 1 from the timing signal generation circuit a
No. S (Fig. 6 C) is supplied to the delay circuit (16), which generates a delay force corresponding to the distance between the rotating head (IA) (IB) and the mounting position of the pulse generator (1). After that, the signal is supplied to the input terminal of an edge detection circuit (8A), and an edge, for example, a falling edge, is detected as a recording reference of the pilot signal. Incidentally, the falling edge of the signal S3 (FIG. 6D) delayed by the delay circuit (16) is made to coincide with the time at which the first heel of jα contacts the tape during the first rotation period.

(178>, (nB), (17C) and (17D) are delay times TL (L), respectively (times corresponding to the intervals of the pilot signal P, erasure signal E and EO recorded on the rack) , T (time corresponding to a half-rotation period of the head/nod), Lp and -tp. Signal S3 from delay circuit (16) (Fig. 6D)
are supplied to delay circuits (178) and (17B), respectively.

The signal S4 (Fig. 6E) from the delay circuit (17A) is supplied to the edge detection circuit (88),
The signal Ss (FIG. 6F) from 1) is directly supplied to the edge detection circuit (8B), and is also supplied to the delay circuit (17A).
) is delayed by time T1 and is supplied to the edge detection circuit (8B) as a ζ signal S6 (FIG. 6G).

Signal S7( from edge detection circuits (8A) and (8B)
FIG. 6H) and signal Ss (FIG. 6) are delayed by times tp and -tp in delay paths (17C) and (170), respectively, to form signal Ss (FIG. 6J) and signal Sh.

(Fig. 6K), the signal S9 is - of the OR circuit (8C).
It is supplied to the input terminal and the delay circuit (17D)
The signal is delayed by tp and becomes a signal 511 (L in FIG. 6). This signal S1'l is supplied to the negative input terminal of the OR circuit (8D) and is delayed by time -tp in the delay circuit (170) to become a signal 512 (M in FIG. 6). 8E) and the delay circuit (1
70) and is delayed by time -tp to the signal 513 (FIG. 6N).
and is supplied to the other input terminal of the OR circuit (8D).

Further, the signal Sio is supplied to the other input terminal of the OR circuit (8B) and is delayed by a time tK in the delay circuit (17C) to become a signal 514 (O in Fig. 6). ) and is further delayed by a delay circuit (17C) for a time t to become a signal 5la (FIG. 6P), which is then supplied to the other input terminal of an OR circuit (8C).

The signals 81ε (Q in FIG. 6), the signals 517 (R in FIG. 6) and the signal +3ts (S in FIG. 6) from the OR circuits (8G), (8D) and (8B) are respectively connected to the recording waveform generation circuit ( 7).

(7.DELTA.) and (7B), and the pilot signals P, erasure signals EO and E from the generators fGl, (68) and (68), respectively, are supplied to the recording waveform generating circuit +71. It is taken out as a composite signal S1!+ (Fig. 6) to the output side of the OR circuit (8F) via (7A) and (7B).

(18^) (18B) is a switch circuit (15,
A) An amplifier to which the playback output from the corresponding rotary head (LA) (IB) is supplied when (15B) is switched to the contact P side, and these amplifiers (18^) (
Each output of 18B) is supplied to a switch circuit (19). The switch circuit (19) includes a timing signal generation circuit (
3011z switching signal 81' from 101 (Figure 7A)
As in the case of recording, the half-rotation period including the tape contact period of the head (18) and the half-rotation period including the tape contact period of the head (IB) are alternately switched.

(20) is the passing center frequency r for extracting only the pilot signal P from the reproduction output from the switch circuit (19).
oO narrowband bandpass filter, (21) is a peak hold circuit for holding the peak value of the output of the filter (20) in order to improve response characteristics, and (22) is a peak hold circuit for sampling the held peak value. , a sampling hold circuit for holding, (23) a comparison circuit for comparing each output of the peak hold circuit (21) and the sampling hold circuit (22), such as a differential amplifier, and (24) from the differential amplifier (23). This is a sampling and holding circuit for sampling and holding the comparison error signal of these sampling and holding circuits (2).
2) (24) is substantially as explained below.)
At the time of 11th generation, the crosstalk of each pilot signal recorded in the Ii'Iil end portions of the tracks on both sides adjacent to the track currently being scanned is sampled and bolded (@J<. Then, the sampling hold The output of the circuit (24) is taken out as a tracking control signal via a switch circuit (25) to an output terminal (26).

Also, sampling hold circuit (22) (24)
A gate circuit (27) whose gate is controlled by a mask signal SM (FIG. 7E) as described later is provided on the output side of the switch circuit vR (19) in order to form sampling pulses, etc. A narrow band band pass filter (28
), and its output Sa (Fig. 7G) is waveform-shaped by a waveform shaping circuit (29) and becomes a signal 52o (Fig. 7H).
).

(30) is a rising edge detection circuit for detecting the rising edge of the signal from the waveform shaping circuit (29), and as mentioned above, the rising edge of the erasing signal is detected every half rotation period of the head. . The output 521 (FIG. 7I) of the detection circuit <30) is supplied to the pulse setting selector (31) to select the pulse setting! (31) generates a narrow signal 522 (FIG. 7J) on its output side in synchronization with the signal S21. Note that the gate circuit (27) may be located after any one of the band pass filter (28), the waveform shaping circuit (29), or the rising edge detection circuit (30).

(32) is a pulse generation circuit using a counter, for example, and the signal S2? from the pulse setting selector (21)? The clock from the clock terminal (33) is counted as a trigger pulse, and a pair of pulses P are output at a predetermined interval on the output side.
i (Fig. 7K) is generated corresponding to each pilot signal to be detected.

This pulse Pi is supplied to a peak hold circuit (21) and also to a sampling pulse ordering circuit (34) using, for example, a D-type flip-flop circuit.

A sampling pulse generation circuit (34) generates a sampling pulse SPY in response to the pulse Pi.

SF3 is connected to sampling hold circuits (22) and (24).
) will occur.

(35) is an equalizer provided on the output side of the switch circuit (19), (36) is a PLL circuit for generating a clock for signal extraction, and (37) is a D-type Frisopflop circuit. ) is supplied as data to the input terminal of the flip-flop circuit (37), and the clock from the PLL circuit (36) is supplied to the clock high 1; Output part 1 child Q of 1 Raku (37)
(Digital signals are extracted according to the rules.

This digital signal is sent to the output terminal (38).
The signal is extracted from the output terminal (38) and is further supplied to a reproduction processor (not shown) connected to this output terminal (38), where it is restored to the original analog signal.

Further, the digital signal from the flip-flop circuit (37) is taken into the shift register (39), and its contents are determined at the pattern determination port vf (40). The pattern determination circuit (40) determines whether the contents of the shift register (39) are a specific pattern, ie, Sub Code in this case.
is a fixed 5 of 10 bits in a block of PCM data.
If it is a YNC pattern, one pulse signal Sa (FIG. 2C or FIG. 7D) is generated on its output side. When this pulse signal Sa is generated, the pulse width setting circuit (41) provided on the output side of the pattern determination circuit (40)
) generates a mask signal SM (FIG. 7E) having a predetermined pulse width, for example, about 360 bits, from the pulse signal SG. This mask signal SM is supplied as a gate signal to the above-mentioned gate circuit (27), and the gate circuit (
27) opens its gate only when the mask signal SH is at low level, and outputs the output SR (27) from the switch circuit (19).
C) in FIG. 7, that is, the mask signal SM
Sub Code acts to completely mask the PCM data part, and as a result, Sub Code P
All random signal parts in CM data are blocked 1
Sub Code, outside of this cut off period.
Signals other than PCM data are passed through to substantially produce the window effect.

Further, (51) is a comparison circuit provided in accordance with the output of the filter (28), and this comparison circuit (51) is connected to the output of the filter (28), that is, the reproduced output of the erasing signal E and the reference power source ( 52), and if the playback output exceeds the reference value, the output signal 523 (8th
C) in the figure is generated and supplied as a latch pulse to the clock terminal of the I] type flip-flop circuit (53). Further, a circuit (54) for detecting, for example, the falling edge of the switching signal 81' from the timing signal generation circuit α0) is provided, and the output signal 524(
E) in FIG. 8 is generated and supplied to the terminal R of the flip-flop circuit (53) as a reset signal. Further, the switching signal 31' is inverted by the inverter (55) to become a signal 81' (FIG. 8F), which is supplied to the input terminal of the flip-flop circuit (53).

Further, a circuit (56) for detecting, for example, the rising edge of the switching signal s11 is provided, and generates an output signal 525 (FIG. 8G) in synchronization with the rising edge of the switching signal 3, l, and outputs a D-type flip-flop as a clock signal. It is supplied to the clock terminal of the circuit (57). The output signal 32B (Fig. 8H) of the flip-flop circuit (53) is supplied to the input terminal of the flip-flop circuit (57), and the output signal 827 (Fig. 8 1) of the flip-flop circuit (57) is supplied to the input terminal of the flip-flop circuit (57). It is used as a switching control signal for the circuit (25). That is, as will be described later, when the control signal S2T is at one level, for example, bending hell (H), the switch circuit (25) is connected to the contact a side and outputs the tracking control signal to the output terminal (
26) and performs the operation 1lT1, but the control signal S2? When the other level is low level (L), it is connected to the contact side and a constant potential VC is applied from the terminal (58).
C is taken out to the output terminal (26) and applied as a tracking control signal to the capstan servo system to force the scanning head to enter a proper tracking state.

Next, the operation of the circuit shown in FIG. 3 will be explained with reference to the signal waveforms shown in FIGS. 6 to 8.

First, during recording, a pulse PC is generated from the pulse generator (11) indicating the rotational phase of the rotary head (1Δ) (IB).
in response to the sixth signal from the timing signal generation circuit QOI.
A signal S7 as shown in Figure C is generated, and this signal S2 is i21! delayed by a predetermined time TR in a delay circuit (16);
As a result, a signal S3 as shown in the sixth figure is outputted to the output side. This signal S3 is processed directly and via the delay circuit (17A) as described above.

This is supplied to the edge detection circuit 11 (88), which detects the edge (
A narrow (g signal S7) as shown in FIG. 6 (I) is activated on the output side in synchronization with this edge. and (17A
) are supplied to the edge detection circuit (8B), which detects the edge (rising edge) and, in synchronization with this edge, outputs the signals shown in FIG. 6I. A signal SL1 like this is generated.Signal Sv.

S8 are supplied to delay circuits (17G) and (170), respectively, and are delayed as described above (see Figure 6 J-P).
, As a result, on the output side of the OR circuits (8C) to (8B),
Signals SIG to S1g as shown in FIG. 6 Q-3 are taken out, and these signals 5IGISIT and S1e substantially correspond to the pilot signal P by the heads (IA) and (IB), the erasure signal Eo and The standards for starting recording of the erasing signal E are determined respectively.

Signals Sxs, Stv and Sts are respectively sent to the recording waveform ordering circuit +71. (7A) and (7B), and the recording waveform ordering circuit (7) outputs the pilot signal P from the oscillator (6) at predetermined intervals as shown in FIG. 6Q in synchronization with the supplied signal SIG. The recording waveform generating circuit (7A) generates the erase signal E from the oscillator (6B) in synchronization with the supplied signal 317.
o is conducted for a substantially predetermined time tp at predetermined intervals as shown in FIG.
i! The erasing signal E from 3 (6A) is transmitted for a predetermined time -tp at predetermined intervals as shown in FIG. 6S.

The output signals from the recording waveform generating circuits (7), (7A), and (7B) are passed through an OR circuit (8F), so that a signal 51s as shown in FIG. 6T is taken out at its output side.

Incidentally, at this time, if we consider, for example, that the head (IB) is recording track (5B2) in FIG. 5, the first and second pulses of the signal 31G in Q in FIG. 6 are the pilot signals P^2 and Corresponding to Ph4, the first and second pulses of the signal SLT in FIG. , the first and second pulses of the signal Ss@ in FIG. 6S correspond to the erasing signals EA2 and EA4 adjacent to the EO, respectively, and the signals Ph3. EO, E^
The combined signals of 21EO and EA41EO+Ph4 are taken out to the output side of the OR circuit (8F) for each group.

Furthermore, for example, if we consider a case where the head (1^) is recording the track (5A2) in the fifth nut 1, the first and second pulses of the signal S18 in Q in FIG. 6 correspond to the pilot signals PB2 and PH4, respectively. Correspondingly, the first and second pulses of the signal Ssv in FIG. 6R are the erasing signal EB.
2 and both sides of the erasing signal EB4, respectively, and the signal S in FIG.
The first and second pulses of ll correspond to the erasing signals EB2 and EO adjacent to the above Eo, respectively, and are signals corresponding to the arrangement of these signals, that is, Ea2+ Eo r P
The composite signal of H1 and P841EorEH11EO is taken out to the output side of the OR circuit (8F) for each group.

On the other hand, the timing signal generating circuit αω generates a switching signal s1 as shown in FIG. 6A in response to the pulse PC from the pulse generator (11). ) (18), and as shown in FIGS. 6A and B, the head (IA
) comes into contact with the tape (2) and the head (IB) contacts the tape (2) within the half-rotation period IB during which the signal Ss is at a low level.
2). Then, the switch circuit (9) is switched to the state shown in the diagram during the period t^ and to the state opposite to the state shown in the diagram during the period tB, respectively, by the switching signal Sl, thereby performing head switching.

Therefore, the signal S1 obtained on the output side of the OR circuit (8F)
9 indicates that when the switch circuit (9) is in a state opposite to that shown in the figure, the amplifier (14B) and the switch circuit (15B)
) is supplied to the head (IB) through the R side of
At the beginning and end of the period of contact of the head (IB) in B with the tape (2), as shown in FIG.
The tracking signal recording areas At+ and AT2 provided at the j111 end portion equidistant from the longitudinal center position of are recorded for a time tp+-tp, respectively.

On the other hand, when the switch circuit (9) is in the state shown in the figure, the signal S1s is transmitted to the amplifier (14A) and the switch circuit (15).
^) is supplied to the head (IA) through the R side, and the period L
At the beginning and end of the contact period of the head (1^) in A with the tape (2), as shown in the same figure, both ends of the track (5^) in the longitudinal direction where the track (5^) has been cut by an amount corresponding to In addition to the above-mentioned recording area ATi provided in the above-mentioned portion, and the audio PCM signal of the 1-segment portion that should be recorded as one track, although not shown, except for the time when these pilot signals and erasing signals are recorded. However, the period t^
In the period to, the signal is supplied to the head (l^) through the amplifier (14A), and in the period to, it is supplied to the head (IB) through the amplifier (14B), and the signal is supplied to each track (5A) (
5B) Recorded in a recording area API other than the pilot signal recording area described above.

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

Even during this internal generation, drum phase servo is applied to the motor (12) by the phase servo circuit (13) in the same manner as during number recording.

The tape (2) is rotated by the rotating head (18) and (IB).
The signals taken out from the respective switch circuits (15A
) contact P side and amplifier (18A) and Sui Nochi circuit (
The signal is supplied to the switch circuit (19) via the contact P side of 15[1] and the amplifier (18B). This switch circuit (1
9) is a switching signal 81' of 3011z as shown in the N47 picture from the timing signal generation circuit, and δ includes the tape contact period of the head (1^) and the half-rotation period L^ as in the case of self-recording. , half-rotation period including the tape contact period of the head (IB) 1. can be switched alternately. therefore,
This switch circuit (19) outputs an intermittent 1 segment SR as shown in Figure C, which passes through an equalizer (35) to the output side of the flip-flop circuit (37). It is extracted as a digital signal and fed to the output terminal (38) (J4).Then, it is further fed to a playback processor (not shown), demodulated to the original PCM signal, and further fed to a decoder to generate a block synchronization signal. The data for each block is detected, error correction, de-interleaving, etc. are performed, and the D/A
The converter converts it back to an analog audio signal and outputs it to the output side.

Tracking control is performed as follows.

Now, for example, the head (IB) has a scanning width W including a track <582) as shown by a dashed line in FIG.
, the head (IB) scans the tracks (5A2) (5B2) on both sides of this track (5B2).
^1), and scan the area A as shown in Figure 5.
In the second case, the pilot signal P^2 of the truck (5[12), the pilot signal PB2 of the adjacent truck (5A2) on both sides, and the pilot signal P of the truck (5A1).
81, and in area A-2, the pilot signal PB4 of the adjacent lit rack (582) and the truck (582) are
^1) pilot signal P83 and truck (5B2
) and the pilot signal PA4. At this time, the playback output of the head (IB) from the switch circuit (19) is transmitted through a narrowband bandpass filter (20
), and as shown in FIG. 7F, only the pilot signal is taken out as its output SF, and this is supplied to the peak hold circuit (21).

In addition, the output SR of the switch circuit (19) is connected to the gate circuit (
27) to a bandpass filter (28). The gate circuit (27) opens its gate only when the mask signal SH from the pulse width setting circuit (4I) as shown in FIG. 7E is at a low level, so that at least Sul+ Code
Then, the PCM data portion is masked, and an erasing signal Sf having a frequency f1 as shown in FIG. 7G is extracted. This signal is supplied to the waveform shaping circuit (29) and converted into a signal 320 as shown in FIG. 7H, after which the rising detection surface v
It is supplied to R (30), and its rising edge is detected at \.

On the output side of the rising edge detection circuit (30), as shown in FIG. A narrow signal S21 that coincides with the starting edge of is obtained.

This signal S21 is supplied to a pulse setting selector (31). The pulse setting selector (31) sequentially generates a signal S22 that matches the signal Sn, as shown in FIG. 7J.

This signal S22 is supplied to the pulse generation circuit (32),
Here, based on the signal S22, as shown in FIG.
A pair of pulses Pi corresponding to each pilot signal to be detected is formed, and the sampling pulse generation circuit (3
4) and a peak hold circuit (21). Based on the pair of pulses Pi, the sampling pulse generation circuit (34) generates sampling pulses SP1 and SF3 as shown in Fig. 7 and M.
The signals are supplied to sampling and hold circuits (22) and (24), respectively.

The pulse Pi obtained in this way is supplied to the peak bold circuit (21), and the sampling pulses SP+ and SF3 formed based on this pulse Pi are supplied to the sampling hold circuits (22) and (24), respectively. That will happen.

Therefore, while the head (IB) is scanning the track (5B2), as is clear from FIG. The crosstalk of the pilot signals PR2 and Pa4 of the adjacent track (51h) on the opposite side to the direction is peak held in the peak bold circuit (21), and the output of the peak hold circuit (21) at this time is output to the sampling hold circuit ( 22), is sampled by the sampling pulse SPs generated at the falling edge of the first pulse PL1, and is supplied to one input end of the differential amplifier (23) as a leading phase tracking signal.

Further, the pulse PL2 of 9A2 of the pulse Pi is the pilot signal p of the adjacent track (5Al) on the tape transport direction side.
A peak hold circuit (
21) enters a peak hold state, and the output of the peak bold circuit (21) at this time is output to the differential amplifier (
23) as a tracking signal with a delayed phase. Therefore, the differential amplifier (23) sequentially compares the tracking signals corresponding to the crosstalk of the pilot signals PB2, Pa4, and PBI, respectively.

The comparison error signal from the differential amplifier (23) is then supplied to the sampling hold circuit (24), where it is sampled by the sampling pulse SP2 generated at the falling edge of the second pulse PL2. Therefore, the differential amplifier (
23) The difference in force between the two people is used as a tracking control signal i
This is supplied to the capstan motor (not shown) from the output terminal (26) via the contact a side of the switch circuit (25) to control the amount of tape transport, and the tape is supplied to the differential amplifier (23). When the difference in the level of human power is zero, that is, when the head (IB) scans the track (5B2), it is controlled so that it spans the two tracks (5A2) and (5^1) on both sides by the same amount. That is, the head (IB) is controlled to scan so that the center position of the gap in the width direction coincides with the center position of the track (5B2).

The same process is performed for other tracks. For example, when the head (1Δ) scans the track (51h), as shown on the right side of FIG. (582) pilot signal P^
Since the crosstalk of s, PAT and P^2+ P^ can be obtained, this etc. can be handled using the peak hold circuit (as described above).
21), the peaks are sequentially bolded, and the sampling pulse generation circuit (44) to the sampling hold circuit (22)
The sampling pulse SPi supplied to the pilot signal P^5. The crosstalk of the PAT is sampled to obtain a tracking section sequence, which is supplied to the next stage difference υ amplifier (23) and is also used as a pilot signal P^2.
Supply the output from the peak hold circuit (21) corresponding to the crosstalk of P^, and compare the tracking signals corresponding to the crosstalk of the pilot signals P^5 and PA2, PAT and P^, respectively. Then, each time the comparison error signal is sampled with the sampling pulse SP2 supplied to the sampling bold circuit (24),
A tracking control signal for the head (18) can be obtained.

Similarly, track (583) is connected to the head (IB).
) scans, as shown in FIG. 5, the pilot signals P R5, P II? And since the crosstalk of PO2 and PH1 is obtained, the pilot signal P 86+
P B? The crosstalk of is sampled with the sampling pulse SP1, and the differential amplifier (23) outputs the pilot signal P115 and PR2%PB? A tracking control signal for the head (1B) can be obtained by comparing the tracking signals corresponding to the crosstalk of the head (1B) and PH1, and finally sampling the comparison error signal with the sampling pulse SP2.

In addition, in this embodiment, as described above, the frequency f1 of the erasing signal E is selected in advance to a value with a relatively large azimuth loss, and therefore the head outputs the azimuth and the amplifier 1 of the track being scanned. The relationship between the erase signal E and the signal cannot be ignored, and the crosstalk component of the erasing signal E will be reduced accordingly if the azimuth is different, that is, if the track is shifted from the track being scanned and enters an adjacent track.

Therefore, in this embodiment, when the amount of track deviation of the head is within a predetermined range, the normal operation of detecting the tracking error output according to the amount of track deviation as described above and performing tracking control is performed, and the tracking control is performed as described above. When the amount of deviation exceeds a predetermined range, the control amount is fixed at a certain potential Vcc, thereby forcing the head to perform tracking control.The reference value to be compared at this time is Playback output of erase signal E (reverse azimuth) for the P14 contact track when the head is scanning a track with the same azimuth, and l!J contact track removal output when the head is scanning a track with the opposite azimuth. Determine the minimum value so that it is larger than the reproduction output of the signal E (same azimuth) on the west side of the level, and erase the track when the head is scanning tracks of the same azimuth. The maximum value is determined so as to be smaller than the reproduced output of the signal E, and the reference value is set anywhere between the minimum value and the maximum value.

Furthermore, to explain in detail the setting of this base $ value, in order to set this base value without considering the influence of jitter etc.,
For example, in the 51i1, when the head (IB) scans the track (5[12) with just tracking,
The maximum value is smaller than the reproduction output of the erasing signal E A2 of the same azimuth, and the minimum value is the erasing signal EB2 or EBI of the opposite azimuth of the adjacent track (5A2) or (5^1).
Adjacent track (51h) or (5B2) when scanning a reverse azimuth track (582) or (58) with just tracking, which is larger than the playback output of the head (IB) and is shifted by one track. The reproduction output of the erasing signal E^5 or EA2 (both have the same azimuth) or P/dii
Erase signal E^ of track (5B2) or (581)
2 or E^1 (both have the same azimuth), and set the reference value within the range between the maximum value and the minimum value.

However, if there is ha due to jitter, etc., as in this embodiment, if the recording time of the erasing signal E is at least less than the recording time of the pilot signal P (equivalent to -1 in this embodiment), during scanning Since the erasing signal E of both tracks in contact with the track PA is partially duplicated, and the starting edge of the erasing signal E cannot be detected, a self-clock cannot be formed, and there is a possibility that tracking control may malfunction.

For example, if the end of the erasing signal E^5 and the beginning of the erasing signal E^2 become distorted due to the influence of jitter, etc., the head (IB) will shift by one track and the track of the opposite azimuth ( 582) is scanned by just tracking, the erasing signals IEΔ5 and EA2 have the same azimuth.
Each time the sum of the playback outputs is detected.

Therefore, as mentioned above, even if the playback output is set to be larger than E^5 or E^2, which is one of the conditions for the minimum value of the reference value, it may cause malfunction. Therefore, in this case, the minimum value is at least It is necessary to make the value larger than the sum of the reproduction outputs of the above-mentioned erasing signals E^5 and E^2, and the range for setting the reference value in the comparator circuit (51) becomes narrower accordingly.

Therefore, in this embodiment, as described above, the erasing No. 1 E is recorded so that its starting end is located near the center of the pilot signal P of the adjacent track, and at least the ending end is located near the center of the pilot signal P of the adjacent track. Make it end near the end,
In other words, the recording time of the erasing signal E is made to be at least longer than the recording time of the pilot signal P, thereby avoiding the above-mentioned overlap between the erasing signals E. Therefore, in this embodiment, there is no need to set a reference value that takes into consideration the overlap between these overlapped erasing signals E, and the minimum value can be set wider, even if there is an influence of jitter etc. , the setting range of the reference value can be widened.

Incidentally, in this embodiment, the minimum value of the reference value is the reproduction output of the erasing signal E (reverse azimuth) of the adjacent track when the head is scanning tracks of the same azimuth, and the
Among the playback outputs of the erasing signal E (same azimuth) of the adjacent track when scanning a track with a reverse azimuth shifted by one track, the playback output of the higher level one is determined to be thicker (determined to be the maximum The value may be determined in the same manner as described above.

Note that the influence of jitter within the time -tP is sufficiently absorbed and suppressed mechanically.

Therefore, if the detected crosstalk output of the erasing signal E exceeds this lqli value, the signal S21 is generated as described above, and the sampling pulses SPI and SP2 are formed based on this. , if it is less than the base 216 value, the head is already scanning the reverse track and the signal S2 is
1 is not generated and therefore the sampling pulse SP1. S
P2 is also not formed.

Therefore, in this embodiment, the erasing signal E
If the crosstalk output is less than this value, it is assumed that the head is significantly out of track, and the head is forcibly shifted to the correct position.

This operation is performed by the circuits after the comparator circuit (51) shown in FIG. 3. The zero-order circuit operation will be explained with reference to FIG. ff18.

Now, a filter (2) is connected to one side of the comparison circuit (51).
8) is supplied as shown in FIG. ,
When the signal SE is larger than the reference value, a signal 521 as shown in FIG. 8C is generated at the output side of the comparison circuit (51) and is supplied to the flip-flop circuit (53) as a latch pulse. On the other hand, prior to the generation of this signal S23, the falling detection circuit (54) detects the switching signal st' (FIG. 8D).
) is detected, a signal S24 as shown in FIG. 8H is generated on the output side of the signal S24, and the flip-flop circuit (
53) is reset as shown in FIG.

Further, the input terminal of the flip-flop circuit (53) is supplied with a switching signal 81' as shown in FIG.
When the 71 circuit (53) is supplied with the signal 523 (latch pulse), it generates a high level (H) signal 32g on its output side as shown in FIG. ).

In addition, the switching signal 31/
When the rising edge of is detected, a signal S25 similar to that shown in FIG.
57) is supplied to the clock terminal.

At this point, a high level signal S2T is generated on the output side of the flip-flop circuit (57) as shown in FIG. 8, and is supplied to the switch circuit (25) as a switching control signal. The switch circuit (25) is connected to the contact a side when the signal S21 is bent, so the output terminal (26) is connected to the zumbling hold circuit (24) side. Trunking control signals are derived.

On the other hand, if No. 15 SE is greater than the reference value, the comparison circuit (
Since the signal 323 is not generated at the output side of the flip-flop circuit (51), the flip-flop circuit (53) remains reset to the signal S24, and its output signal 326 is at a low level (L) as shown by the broken line in FIG. 8H. is maintained. In this state, the output of the flip-flop circuit (57) (*j+S
2? is also at the quotient level, as shown by the broken line in Figure 8 (■).

Then, at the rising edge of the switching signal 81', the detection circuit (56)
When the signal 525 (FIG. 8G) is supplied from the flip-flop circuit (57), the output signal S27 of the flimp float circuit (57) changes from high level to low level as shown by the broken line in FIG. 8, and this low level signal S2 ? is supplied to the switch circuit (25), and the switch circuit (25) switches to the contact side. As a result, the output terminal (26) has a constant potential V from the terminal (58).
A signal with cc is derived, and this signal is supplied to a capstan servo system (not shown) to perform tracking control.

For example, when the constant potential Vcc is positive, the tape is advanced through the capstan servo system, so the head essentially moves to the next track corresponding to its own azimuth and performs a compact tracking operation. Also, the potential Vcc is O
In this case, the tape advance is slowed down so that the head is essentially pulled back to the track it is currently scanning, thereby entering normal tracking operation.

In this way, in this embodiment, the 5YNC Bakun of Sub Code and PCM data is determined, and when this 5YNL: pattern is detected, the entire block is substantially masked. Erroneous detection of the positioning signal of the tracking pilot signal can be prevented without generating a wind signal based on the PC signal as in the past.

In addition, the pilot signal erasure signal E has a frequency with a relatively large azimuth loss, and is also used as a pilot signal positioning signal, which simplifies the circuit configuration for extracting the so-called self-crotter. Performance can also be improved.

Further, in this embodiment, during playback, the pilot signal is detected substantially based on the starting edge of the playback output of the erase signal E recorded in the track, and the sampling pulse is self-generated. Since the self-clock is generated substantially from the track pattern, adverse effects such as offset when using the pulse PC as a reference are eliminated.

In addition, an erasing signal E having a frequency where azimuth loss is effective
When the crosstalk output of the head is below the reference value, the control amount is forcibly fixed at a constant potential to perform head tracking control, which enables highly accurate tracking control.

In addition, each head generates a sampling pulse as described above during each scanning period of each head to detect the tracking position. In other words, each head generates a self-clock as a sampling pulse each time on the track pattern, and each track Since the tracking position is detected, the influence of jitter is also eliminated.

Furthermore, since we are recording in such a way that the starting edge of the erasing signal E, which detects the position of the pilot signal, is located near the center of the pilot signals of adjacent tracks, we take the trouble to set the starting edge of the erasing signal E to the position of the pilot signal. There is no need for a circuit for delaying the position near the center, and the circuit configuration is simplified accordingly. Furthermore, since the recording time of the erasing signal E is made to be at least shorter than the recording time of the pilot signal P, the erasing signal E of adjacent tracks is held at a predetermined interval, and therefore, the recording time due to the influence of jitter etc. The erasing signal E that has been erased does not substantially overlap between adjacent tracks, and as a result,
It is possible to provide some leeway in the setting range of 1 & quasi-value in 1).

The above-mentioned embodiment is a special rotary head device that records and reproduces data by winding the tape over an angular range narrower than the head angular interval. Of course, the present invention can also be applied to a case where a rotary head device is used.

Effects of the Invention As described above, according to the present invention, it is possible to determine the positioning signal of the tracking pilot signal and the fixed pattern (SYNC pattern) of signals such as Sub Code and PCM data, which are frequency components that may be erroneously detected. If this fixed pattern is determined, the subsequent incoming signals are blocked for a certain period of time, and Wind No. 13 can be generated from the PCM signal itself, so it is possible to use the conventional PC signal as a reference. This eliminates the need to generate a wind signal, which makes it possible to reduce the positional relationship between the PG signal and the head and the L sound of the drum during playback, and to reduce costs.

Furthermore, when a recording track is scanned by a rotating head, a frequency with a relatively large azimuth loss that has its start end near the center of the pilot signal of an adjacent track and is recorded in a manner that is more rectangular than the recording time of the pilot signal. A pulse signal is formed to detect this pilot signal using the starting edge of the erasing signal E having a reference value as a reference, and a tracking control signal based on the detection output is used to control the tracking of the rotary head, and the reproduced output of the erasing signal E is set to a reference value. In the following cases, the tracking control of the rotating head is performed by fixing the control amount to a constant potential.
Even if there is mechanical aging, temperature change, or jitter in the device, the device will not be affected by them in any way, and the device will be different during playback from that during recording.
rJ can be carried out with good accuracy, and compatibility between equipment phases J14 can be achieved.

Furthermore, since the erasing signal E for detecting the position of the pilot for tracking control is recorded so as to have its start end near the center of the adjacent pilot signals, it is necessary to locate the start end near the center of the pilot signals. This eliminates the need for a delay circuit, and simplifies the circuit configuration accordingly.

Furthermore, the recording time of the erasing signal E is made to be at least shorter than the recording time of the pilot signal P, and the erasing signals E of adjacent tracks are separated by a predetermined interval. When the track erasing signals E are recorded adjacent to each other, the comparison circuit (51)
The setting range of the reference value can be expanded, and the influence of jitter can also be reduced.

ff of the drawing? 1lJ1 Description Figure 1 shows the track pattern, Figure 2 shows the track pattern. :J is a diagram for explaining the basic principle of this invention, FIG. 3 is a circuit configuration diagram showing an embodiment of this invention, and FIG. 4 is an example of a rotary head device used in FIG. 3. 5 shows an outline of the recording track pattern of this invention.
The figure is a signal waveform diagram for explaining the recording operation in Figure 3, Figure 7 is a signal waveform diagram for explaining the reproduction operation in Figure 3, and Figure 8 is an explanation for the reproduction operation in Figure 3. FIG. 2 is a signal waveform diagram for use in

(I8) (IB) is a rotating magnetic head, (2) is a magnetic tape, (6) is a pilot signal oscillator, (6A)
, (6B) is the oscillator of Ig for erasing, +71.
(7^), (7B) are recording waveform generation circuits, (16),
(178) to (170) are delay circuits, (8A),
(8B) is an edge detection circuit, (20), (2
8) is a band pass filter, (21) is a peak hold circuit, (22) and (24) are sampling and hold circuits, (23) is a differential amplifier, (25) is a switch circuit, (27) is a gate circuit, ( 29) is a waveform shaping circuit,
(3o) is a rising edge detection circuit, (31) is a pulse setting selector, (32) is a pulse generation circuit, (34) is a sampling pulse generation circuit, (35) is an equalizer, (36)
is a PLL circuit, (37) is a D-type flip-flop circuit,
(39) is a shift register, (40) is a pattern determination circuit, and (41) is a pulse width setting circuit.

Claims (1)

[Claims] In a digital signal recording and reproducing apparatus that compresses the time axis of a digital signal, forms and records diagonal tracks on a recording medium using a plurality of rotary heads without forming a guard band, and reproduces the tracks, each of the above-mentioned tracks is used. In the longitudinal direction, a plurality of tracking pilot signals are recorded independently from the digital signal as a recording area, and a plurality of tracking pilot signals having a starting edge near the center of the pilot signal of the adjacent track and having a frequency with relatively large azimuth loss are recorded. The positioning signal is recorded so that the recording time is at least shorter than the recording time of the pilot signal, and when the recording track is scanned by a rotary head whose scanning width is wider than the width of the track during playback, the positioning signal is recorded on each of the tracks. A fixed pattern in the recorded signal is determined, and if the fixed pattern is determined, the signal following the fixed pattern is interrupted for a certain period of time, and a pulse signal is generated with the starting edge of the positioning signal as a reference outside of this interruption period. , the pilot signal is detected from a related track being scanned by the rotary head during the period of the pulse signal, and the detection output is used to perform tracking control of the rotary head. recording and reproducing equipment.