JPH07107761B2 - Digital signal playback device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention converts, for example, a video signal or an audio signal into a PCM signal, and records this as a diagonal track on a recording medium by a rotary head for each unit time. The present invention relates to a digital signal reproducing apparatus suitable for use in reproducing the same.

[Conventional technology]

A helical scan type rotary head device is used to output video signals and audio signals on a magnetic tape every 1 minute.
When forming and recording diagonal tracks of each book and reproducing the same, it is considered to record and reproduce the video signal and the audio signal by converting them into PCM. This is because high-quality recording and reproduction can be performed by using PCM.

In this case, in the tracking control for ensuring that the rotary head correctly scans the recording track at the time of reproduction, conventionally, a control signal recorded on one end side in the width direction of the tape by a fixed magnetic head is used for the fixed head. In general, the reproduction control signal and the rotational phase of the rotary head have a constant phase relationship.

However, in this method, a fixed magnetic head must be provided for tracking control.

Providing such a fixed magnetic head causes inconvenience in relation to the mounting location and the like when it is desired to downsize the recording / reproducing apparatus.

Therefore, a method of performing tracking control of the rotary head by using 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 can be easily compressed / expanded on the time axis. Therefore, unlike the analog signal, it is not always necessary to record and reproduce the signal continuously in time, and therefore, an area is formed on one track. This was done by paying attention to the fact that it is easy to record the PCM signal separately from the PCM signal separately.

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. A plurality of tracking pilot signals are independently recorded as areas, and during reproduction, the recording track is scanned by a rotary head whose scanning width is wider than the track width, and the rotary head scans pilot signals from both adjacent tracks. Is used to control the tracking of the rotary head.

By the way, a special reproduction mode in which the trajectory is shifted by a predetermined amount and the tracking control is performed in a so-called offset state with respect to the normal reproduction mode in which such tracking control is performed can be considered. For example, what is called after-recording in which only a specific area is rewritten corresponds to this (note that special reproduction described below in this specification refers to after-recording).

As a method of performing tracking control by offsetting a predetermined amount from the normal reproduction mode in such a special reproduction mode, conventionally, there is a method of supplying a constant voltage corresponding to the offset amount to the capstan servo system as a tracking control signal. is there.

However, in the case of such a conventional method, when the track is bent or the sensitivity of the tape or the head is changed,
There is a risk that the offset amount will be reached and that an inaccurate offset amount cannot be given.

[Problems to be solved by the invention]

The present invention has been made in view of the above point, and even if the track is bent or the sensitivity of the tape or the head is changed, a predetermined amount of offset is accurately applied to enable highly accurate tracking control. The present invention provides a reproducing apparatus for digital signals.

[Means for solving problems]

According to the present invention, a plurality of tracking pilot signals P are recorded independently of the digital signal as recording areas in the longitudinal direction of each track, and the adjacent tracks have different frequencies and different recording lengths between tracks for the same frequency. The position-finding signals S and T are repeatedly recorded every predetermined number of tracks, for example, 4 tracks as one cycle, and at the time of reproduction,
When the recording track is scanned by the rotary head having a scanning width wider than the width of the track, a pulse signal is formed with the start end of the positioning signal as a reference, and the rotary head is scanning during the period of the pulse signal. In the recording / reproducing apparatus for a digital signal in which the pilot signal is detected from the track to be used, and tracking control of the rotary head is performed by the detection output, scanning in a plurality of recording areas, that is, areas A _T1 and A _T2 in the normal reproduction mode is performed. Tracking control is performed by detection output of pilot signals from both adjacent tracks adjacent to the inner track, and in special reproduction mode, detection output of pilot signals from both adjacent tracks adjacent to the track being scanned in one recording area and the other Track adjacent to the track being scanned in the recording area of By combining the detection output of the detection output of the pilot signals from the track being scanned is configured to perform tracking control by a predetermined amount offset from the time of the normal reproduction mode.

[Action]

In the normal reproduction mode, the first and second sampling pulses are used to detect the crosstalk of pilot signals of both adjacent tracks adjacent to the track currently being scanned in one recording area, for example, the area A _T1 , and the first and second sampling pulses are detected. Crosstalk between pilot signals on both adjacent tracks adjacent to the currently scanning track in the other recording area, for example, area A _T2 , is detected by the pulse, and tracking control is performed by the combined detection output of both detection outputs. The first and second sampling pulses detect crosstalk between pilot signals on both adjacent tracks adjacent to the currently scanning track in one recording area, and the first sampling pulse detects the currently scanning track in the other recording area. To detect the crosstalk of the pilot signal of the adjacent track The second sampling pulse to detect the pilot signal of the track currently being scanned, the combined output of the detection outputs of both recording area, a predetermined amount than the normal reproduction mode for example 45 ° offset to perform the tracking control.

〔Example〕

An embodiment of the present invention will be described below in detail with reference to FIGS.

FIG. 1 shows the circuit configuration of this embodiment. Here,
Only a circuit configuration for recording and reproducing a tracking pilot signal, a positioning signal and an erasing signal, which are directly related to the present invention, is shown, and a circuit configuration for recording and reproducing recorded information, for example, a PCM signal is omitted. Has been done.

In the figure, (1A) and (1B) are rotary heads, and (2) is a magnetic tape as a recording medium. Rotating head (1A)
And (1B) are equiangular intervals, that is, as shown in FIG.
They are arranged around the drum (3) at intervals of 180 degrees. On the other hand, the magnetic tape (2) is wound around the tape guide drum (3) over, for example, a 90-degree angle range narrower than the 180-degree angle range. Then, the rotary heads (1A) and (1B) show an arrow (4H) at a rate of 30 revolutions per second.
The tape (2) is rotated at a predetermined speed in the direction indicated by the arrow (4T) while being rotated in the direction of, and is rotated by the rotary heads (1A) and (1B) onto the magnetic tape (2) to form a third tape.
One diagonal magnetic track as shown (5A)
(5B) is formed in a so-called overwritten state, for example. That is, the width of the head gap (scanning width)
W is made larger than the track width. In this case, the width directions of the gaps of the heads (1A) and (1B) are different from the direction orthogonal to the scanning direction. That is, the so-called azimuth angles are made different.

And the two rotary heads (1A) (1B) are tapes (2)
There is a period in which they do not touch each other (this is the period for the 90 degree angular range in this example), and redundant data is added during recording and correction processing is performed during playback using this period. By doing so, the device can be simplified.

(6) is an oscillator that generates a tracking pilot signal P, and the pilot signal P is, for example, its frequency.
f ₀ is, 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 oscillators for respectively generating position finding signals S and T for detecting the position of the pilot signal, and these position finding signals S and T are pilot signal erasing signals. Combined with
When a new recording is made on the previously recorded tape after erasing the previously recorded information over the tape, the recording track does not always match the previous recording track. It was intended to be used when it is necessary to erase the pilot signal, the frequency f ₁ and
The frequency f ₂ is, for example, around 700 kHz and 500 kHz, which are practically different from the frequency f ₀ of the pilot signal. Also,
The recording level is also such that the pilot signal P can be practically erased.

Also, (9) is a generator for generating an erase signal E _0, the erase signal E ₀ is thereby pilot signal P
When the position finding signals S and T are overwritten, it is preferable that these signals P, S and T have a high erasing rate, and their frequencies f
_{As 3} is used about 2 MHz, for example.

Reference numerals (10), (11), (12) and (13) denote recording waveform generation circuits, which respond to an edge of a delay signal related to a pulse PG, which will be described later, such as a falling edge, and the generation circuit (10) is an oscillator. Based on the pilot signal from (6), a pilot signal having a predetermined time t _P (t _P is a recording time of the pilot signal etc.) depending on how many pilot signals P are inserted per track and in what arrangement P again, the generation circuit (1
1), (12) and (13) are the number of positioning signals per track based on the positioning signals S, T and the 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 how the S, T and erasing signals E ₀ are inserted. (14) is an OR circuit that logically processes the outputs of the generation circuits (10) to (13).

(15) is a switch circuit for switching the rotary heads (1A) and (1B), which is a timing signal generation circuit (16).
It is switched by the switching signal S ₁ from FIG.
The timing signal generating circuit (16) includes a rotary head (1A) and a rotary head (1B) that are obtained in synchronization with the rotation of the rotary drive motor (18) from the pulse generator (17). 1A)
A 30 Hz pulse PG indicating the rotation phase of (1B) is supplied. Further, the pulse PG and the 30 Hz pulse from the timing signal generation circuit (16) are 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) switched by the switching signal S ₁ from the timing signal generation circuit (16) is amplified by the amplifier (19A) or (19B) and then respectively switched to the switch circuit (20A) or ( 20B) is supplied to the rotary head (1A) or (1B) via the contact R side, and the magnetic tape (2)
Recorded above. The switch circuits (20A) and (20B) are connected to the contact R side during recording and switched to the P side during reproduction.

In addition, the switching signal S ₁ from the timing signal generation circuit (16)
The output signal S ₂ (Fig. 4D) in response to the falling edge of is supplied to the delay circuit (21), and the rotation heads (1A) (1B) and the pulse generator (17) are installed at this position. After a delay corresponding to the interval is made, the recording timing generation circuits (22) to (25)
Is supplied to. Further, the switching signal S ₁ from the timing signal generation circuit (16) is frequency-divided by the frequency divider (21 ') into 1/2 to generate a signal S ₄
(Fig. 4C), and the recording timing generation circuit (23)
Supplied 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 trailing edge of the signal S ₃ (FIG. 4E) delayed by the delay circuit (21) substantially coincides with the time when the first head contacts the tape during one rotation period.

The recording timing generation circuit (22) outputs the time when the signal S ₃ falls during one half rotation period of the head, for example, the half rotation period of the head (1B). With a delay of t _P at a predetermined interval T ₁ , and the time T from the trailing edge of the signal S ₃ during the other half rotation period of the head.
(T is the time corresponding to the half rotation period of the head)
Generate a signal S ₅ (FIG. 4F) of duration t _P at a predetermined interval T ₂ . The recording timing generation circuit (23) synchronizes with the trailing edge of the signal S ₃ at a predetermined interval T ₁ + 3t _P only during one half rotation period of the head, for example, during one half rotation period of the head (1B), for example, the rotation of the head. Odd number of periods duration is eye duration The duration is the even number of head rotation periods Respectively generate the signal S ₆ (FIG. 4G). At the recording timing, the generating circuit (24) outputs the signal from the falling edge of the signal S ₃ only during the other half rotation period of the head, for example, the half rotation period of the head (1A). Only with a delay predetermined interval T ₂ -3t _P, but for example, duration in odd rotation periods of the head The duration is the even number of head rotation periods Respectively generate the signal S ₇ (FIG. 4H). Further, the recording timing generation circuit (25) outputs the time from the trailing edge of the signal S ₃ during one half rotation period of the head at an odd number of the rotation period of the head. Only delayed, duration Signal and time from this signal Only delayed, time The duration of a pair of pulses at intervals of Signal is generated and delayed by the time T + t _P from the trailing edge of the signal S ₃ in the other half rotation period of the head. The duration of a pair of pulses at intervals of Signal, which is delayed from this signal by a time T ₂ -2t _P , to generate a signal having a duration t _P , while at an even number of head rotation periods, the signal S ₃ rises during one half rotation period of the head. Time than going down With a delay of t _{P and} a signal with a duration of t _P , with a delay of T ₁ + 2t _P from this signal. The duration of a pair of pulses at intervals of Signal is generated and delayed by the time T + t _P from the trailing edge of the signal S ₃ in the other half rotation period of the head. The duration of a pair of pulses at intervals of Signal and from this signal Only delayed, duration Signal is generated (see FIG. 4I).

Signals S ₅ (FIG. 4F), signals S ₆ (FIG. 4G), signals S ₇ (FIG. 4H) from the recording timing generation circuits (22), (23), (24) and (25). And signal S ₈ (I in FIG. 4) are recorded waveform generation circuits (10), (11), (12) and (13), respectively.
Substantially as a gate signal to the generator (6),
The pilot signals P from (7), (8) and (9),
Positioning signals S, T and erase signal E ₀ are recorded waveform generation circuit (1
OR circuit (1 through 0), (11), (12) and (13)
The combined signal S ₉ (FIG. 4J) is output to the output side of 4).

(26A) (26B) is a switch circuit (20A) (20B) at the time of reproduction
Is switched to the contact P side, the corresponding rotary head (1
A) The amplifiers to which the reproduction outputs from (1B) are supplied, and the outputs of these amplifiers (26A) (26B) are supplied to the switch circuit (27). Switch circuit (27) includes a half turn period including the tape contact period in the same manner as when the recording head (1A) by the timing signal generating circuit (16) 30 Hz switching signal S _t from (FIG. 5 A), The head (1B) is alternately switched in a half rotation period including a tape contact period.

(28) is a narrow band pass filter having a pass center frequency f ₀ for extracting only the pilot signal P from the reproduction output from the switch circuit (27), and (29) is for envelope detection of the output of the filter (28). Envelope detection circuit, (30) is a sampling hold circuit for sampling and holding the output of the envelope detection circuit (29), and (31) is each output of the envelope detection circuit (29) and sampling hold circuit (30). A comparison circuit for comparison, for example, a differential amplifier, (32) is a sampling and holding circuit for sampling and holding the comparison error signal from the differential amplifier (31), and these sampling and holding circuits (30) (32) are , As will be described later, in the normal playback mode, both ends of adjacent tracks adjacent to the track currently being scanned are Sampling the crosstalk of each pilot signal being recorded, it serves to hold. The output of the sampling and holding circuit (32) is taken out to the output terminal (33) as a tracking control signal.

Further, in order to form sampling pulses for the sampling and holding circuits (30) (32), the switch circuit (2
Narrow band band pass filters (34) and (35) having pass center frequencies f ₁ and f ₂ are provided on the output side of 7) to extract only the position finding signals S and T from the reproduction output, and the outputs thereof are provided. S ₁₀ (FIG. 5 E), S ₁₁ (FIG. 5 F) is supplied to the comparator (37) as a waveform shaping circuit via the switching circuit (36). The switch circuit (36) is a switching signal of 30 Hz from the timing signal generating circuit (16) as in the switch circuit (27).
It is switched by S ₁ ′.

(38) and (39) are sampling pulse generation circuits provided on the output side of the comparator (37), and the sampling pulse generation circuit (38) is synchronized with the leading edge of the output of the comparator (37). To generate the first sampling pulse SP ₁ , and the sampling pulse generation circuit (39) generates the second sampling pulse SP ₂ after a predetermined time t _P from the generation of the first sampling pulse SP ₁ . These sampling pulses SP ₁ and SP ₂ are supplied to sample hold circuits (30) and (32), respectively. Reference numeral (40) is a delay circuit for delaying the signal S ₄ by a time T to obtain a signal S ₂₀ (Fig. 5J). The signal S ₂₀ and the switching signal Si are the sampling and holding circuit (3).
9), as described below,
The content of the positioning signal is determined.

Further, delay circuits (41) and (42), gate circuits such as an AND circuit (43) and a switch circuit (44) are provided to perform tracking control in the special reproduction mode. In the delay circuit (41), the switching signal Si is delayed by a predetermined time T / 2 and supplied as a signal S ₂₁ (K in FIG. 5) to one input terminal of the AND circuit (43). The other input terminal of the AND circuit (43) is supplied with a mode selection signal for the normal reproduction mode and the special reproduction mode from the terminal (45). The mode selection signal is, for example, a low level (L) signal in the normal reproduction mode and a high level (H) signal in the special reproduction mode. The AND circuit (43) controls the switching of the switch circuit (44) by its output according to the level of the mode selection signal. That is, the switch circuit (44) is an AND circuit (43).
When the output of is low level, it is connected to the contact a side and the second sampling pulse SP ₂ from the sampling pulse generating circuit (39) is directly supplied to the sampling hold circuit (32), and the output of the AND circuit (43). Is high, it switches to the contact b side and delays the sampling pulse SP ₂ (4
In 2), the signal is delayed by a predetermined time t _P and supplied to the sampling and holding circuit (32).

Therefore, in the special reproduction mode, when the switch circuit (44) is connected to the contact a side, the sampling and holding circuit (32) is recorded on the track adjacent to the track currently being scanned as in the normal reproduction mode. Although the crosstalk of the pilot signal present is sampled, when the switch circuit (44) is switched to the contact b side, it works to sample the pilot signal itself recorded on the track currently being scanned.

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

First, at the time of recording, in response to the pulse PG from the pulse generator (17) indicating the rotational phase of the rotary heads (1A) (1B),
A signal S ₂ as shown in FIG. 4D is generated from the timing signal generating circuit (16), and this signal S ₂ is delayed by a delay circuit (21) for a predetermined time so that the output side thereof is shown in FIG. E
The signal S ₃ as shown in is output. This signal S ₃ is supplied to the recording timing generation circuits (22) to (25) as described above, and the signal S ₅ as shown in FIG. 4F is generated at the output side of the recording timing generation circuit (22). . Further, the switching signal S ₁ from the timing signal generating circuit (16) is supplied to the frequency divider (21 '), and the signal S ₄ as shown in FIG. 4C is obtained at the output side thereof. This signal S ₄ is the recording timing generation circuit (23)
~ (25) is supplied to the recording timing generation circuit (23) ~
(25) generates a signal S ₆ to S ₈ shown in FIG. 4 G~I in response to the signal S _3, S ₄ respectively its output side.

Signals S ₅ , S ₆ , S _7, and S ₈ are recorded waveform generation circuit (10),
The recording waveform generating circuit (10) is supplied to (11), (12) and (13), and the oscillator (6) is synchronized with the supplied signal S _5.
The pilot signal P from the circuit is passed through for a predetermined time t _{P at} predetermined intervals as shown in FIG. 4F, and the recording waveform generating circuit (11) synchronizes with the supplied signal S ₆ to generate an oscillator ( The positioning signal S from 7) is passed for a predetermined time at predetermined intervals as shown in FIG. 4G, and the recording waveform generating circuit (8) synchronizes with the supplied signal S ₇ to generate an oscillator (8 ), The positioning signal S ₈ from the) is passed for a predetermined time at a predetermined interval as shown in FIG. 4H. Further, the recording waveform generating circuit (13) synchronizes with the supplied signal S ₈ to generate an oscillator. The erasing signal E ₀ from (9) is passed for a predetermined time at predetermined intervals as shown in FIG.

The output signals from the recording waveform generating circuits (10) to (13) are added by the OR circuit (14), so that the output side thereof is shown in FIG.
The signal S ₉ as shown in is taken out.

Incidentally, at this time, for example, when the head (1B) is recording the track (5B ₁ ) in FIG. 3 (t in the first half of FIG. 4).
_B period), the first and second pulses of the signal S ₅ in FIG. _4F correspond to the pilot signals P _A1 and P _A2 , respectively, and the first and second pulses of the signal S ₆ in FIG. 4G are considered. Correspond to the positioning signals S _A1 and S _A2 , respectively, and the first pulse of the signal S ₈ and the second pulse consisting of a pair of pulses in FIG. _4I are one side of the positioning signal S _A1 and both sides of S _A2 . The signals corresponding to the erasing signals E ₀ adjacent to each other, that is, the signals corresponding to the array of these signals, that is, the composite signals of S _A1 , E ₀ , P _A1 and P _A2 , E ₀ , S _A2 , E ₀ are respectively grouped. Each time it is taken out to the output side of the OR circuit (14).

Further, for example, when the head (1A) is recording the track (5A ₂ ) in FIG. 3 (t _A period in the first half of FIG. 4)
Considering the above, the first and second pulses of the signal S ₅ in FIG. _4F correspond to the pilot signals P _B3 and P _B4 , respectively, and the first and second pulses of the signal S ₇ in FIG. The first pulse and the second pulse corresponding to the output signals T _B3 and T _B4 and consisting of a pair of pulses of the signal S ₈ in FIG. _4I are adjacent to both sides of the position output signal T _B3 and one side of T _B4 , respectively. A signal corresponding to the erasing signal E _0, which corresponds to the array of these signals, that is, a combined signal of P _B3 , E ₀ , T _B3 , E ₀ and T _B4 , E ₀ , P _B4 , is ORed for each group. It will be taken out to the output side of the circuit (14).

Also, for example, (1B) is the track (5B ₂ ) in FIG.
Considering the case where is recorded (t _B period in the latter half of FIG. 4), the first and second pulses of the signal S ₅ in FIG. _4F correspond to the pilot signals P _A3 and P _A4 , respectively. The first and second pulses of the signal S _{6 in} FIG. 4G correspond to the positioning signals S _A3 and S _A4 , respectively, and the first pulse of the signal S ₈ in FIG. 4I and the second pulse consisting of a pair of pulses. Is the positioning signal
A signal corresponding to the erasing signal E ₀ adjacent to one side of S _A3 and both sides of S _A4 , respectively, corresponding to the array of these signals, namely S
_A3, E _0, composite signal P _A3 and _{P A4, E 0, S A4} , E 0 is obtained from an output side of the OR circuit (14) for each respective group.

Further, for example, when the head (1A) is recording the track (5A ₃ ) in FIG. ₃ (t _A period in the latter half of FIG. 4)
Considering that, the first and second pulses of signal S ₅ in FIG. _4F correspond to pilot signals P _B5 and P _B6 , respectively, and the first and second pulses of signal S ₇ in FIG. Corresponding to the output signals T _B5 and T _B6 , the first and second pulses of the pair of pulses of the signal S ₈ in FIG. _4I are adjacent to both sides of the positioning signal T _B5 and one side of T _B6 , respectively. A signal corresponding to the erasing signal E ₀ and a signal corresponding to the array of these signals, that is, a combined signal of P _B5 , E ₀ , T _B5 , E ₀ and T _B6 , E ₀ , P _B6 , is OR circuit for each group. It will be taken out to the output side of (14).

On the other hand, from the timing signal generating circuit (16) includes a pulse generator switching signal S ₁ as shown in FIG. 4 A in response to the pulse PG from (17) are generated, the signals S ₁ is rotated head (1A) is synchronized with the rotation of (1B), as shown in Figure 4 a and B, in a half turn period t _a of the head signals S ₁ is at the high level heads (1A) is a tape ( 2) so that the head (1B) abuts the tape (2) within the half-rotation period t _B in which the signal S ₁ is at a low level. Then, the switch circuit (15) is switched by the switching signal S ₁ to the state shown in the figure in the period t _A and to the state opposite to the state shown in the figure in the period t _B , and the head is switched.

Therefore, the signal S ₉ obtained at the output side of the OR circuit (14) is
When the switch circuit (15) is in a state opposite to the state shown in the figure, it is supplied to the head (1B) through the amplifier (19B) and the R side of the switch circuit (20B) and is supplied to the head (1B) within the period t _B. 1B)
At the beginning and end of the contact period of the tape (2) with the tape (2), as shown in FIG. 3, both ends of the track (5B) in the longitudinal direction, which are separated by an equal distance 1 from the center position of the track (5B) in the longitudinal direction. In the tracking signal recording areas A _T1 and A _T2 provided in the respective portions, the time is set at an odd number of the head rotation period (t _B period in the first half of FIG. 4). During the head rotation period and the time at the even number of the head rotation period (t _B period in the latter half of FIG. 4). Recorded during.

On the other hand, when the switch circuit (15) is in the condition
S ₉ is supplied to the head (1A) through the amplifier (19A) and the R side of the switch circuit (20A) and is supplied to the head (1A) within the period t _A.
At the beginning and the end of the contact period of A) to the tape (2), as shown in the same figure, in the longitudinal direction of the track (5A) which is equidistant from the center position in the longitudinal direction of the track (5A). In the same recording areas A _T1 and A _T2 that are provided at both ends as described above, the time is changed in the odd-numbered head rotation period (t _A period in the first half of FIG. 4). During the period of the head rotation, the time is recorded at the even number of the head rotation period (t _A period in the latter half of FIG. 4). Recorded during.

Also, except for the time when these pilot signal, position finding signal and erasing signal are recorded, audio of one segment portion which should be recorded as one track, not shown, is shown.
The PCM signal is supplied to the head (1A) through the amplifier (19A) during the period t _A , and is supplied to the head (1B) through the amplifier (19B) during the period t _B so that each track (5A) (5B) is supplied.
Recording area A other than the above-mentioned pilot signal recording area
Recorded in _P1 .

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

Even during this reproduction, the drum phase servo is applied to the motor (18) by the phase servo circuit (19) in the same manner as during recording.

The signals taken out from the tape (2) by the rotary heads (1A) and (1B) are contact points P of the switch circuit (20A), respectively.
Is supplied to the switch circuit (27) via the amplifier side (26A) and the contact P side of the switch circuit (20B) and the amplifier (26B). This switch circuit (27) is a switching signal of 30 Hz from the timing signal generation circuit (16) as shown in FIG. 5A.
By S ₁ ′, the half rotation period t _A including the tape contact period of the head (1A) and the half rotation period t _B including the tape contact period of the head (1B) are alternately switched by S ₁ ′. Therefore, an intermittent PCM signal S _R for each segment as shown in FIG. 5C is obtained from the switch circuit (27), and this PCM signal is supplied to the reproduction processor (not shown).
The signal is demodulated into a signal and further supplied to the decoder to detect the data for each block by the block synchronization signal, and the error correction, de-interleaving and other processing are performed, and D / A
It is converted back into an analog audio signal by the converter and is output to the output side.

Tracking control is performed as follows.

First, in the normal playback mode, for example, the head (1B)
3 scans a range of the scanning width W including a track (5B ₁ ) as indicated by a dot-dash line in FIG. 3, the head (1B) moves the tracks (5A ₂ ) (5A ₂ ) (5A ₂ ) adjacent to the track (5B ₁ ). ₁ ), the pilot signal P _B3 of both adjacent tracks (5A ₂ ) and the pilot signal P _B1 of the track (5A ₁ ) in the area A _{T1 as} shown in FIG.
And the pilot signal P _A1 of the track (5B ₁ )
In the area A _T2 , the pilot signal P of the truck (5B ₁ )
_A2 , the pilot signal P _{B4 of} both adjacent tracks (5A ₂ ) and the pilot signal P _B2 of the track (5A ₁ ) are reproduced. At this time, the reproduction output of the head (1B) from the switch circuit (27) is supplied to the narrow band pass filter (28) having the pass center frequency f ₀ , and its output S _A as shown in FIG. 5D.
As for, only the pilot signal is taken out and supplied to the envelope detection circuit (29).

In addition, the output S _R of the switch circuit (27) is a narrow band pass filter (34) whose pass center frequencies are f ₁ and f ₂ , respectively,
Is supplied to (35) and its output side is shown in FIGS. 5E and 5F, respectively.
Positioning signals S ₁₀ and S ₁₁ as shown in FIG.
These signals S ₁₀ and S ₁₁ are supplied to the switch circuit (36). When the switching signal S ₁ ′ is low level, the signal S ₁₀ is extracted, and when it is high level, the signal S ₁₁ is extracted and compared. Supplied to the vessel (37).

The comparator (37) compares the supplied signals S ₁₀ and S ₁₁ with a reference value to perform waveform shaping, and a sampling pulse generation circuit (3
Supply to 8) and (39). The sampling pulse generation circuit (38) generates a first sampling pulse SP ₁ as shown in FIG. 5G at the rising edge of the waveform-formed signal S ₁₀ , and this sampling pulse SP ₁ is supplied to the sampling hold circuit (38). 30). At this time, the sampling pulse SP ₁ is shown by the arrow (4
T) (Fig. 3) 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 is sampled, and this sampled signal is the lead phase tracking signal. Is supplied to one input terminal of the differential amplifier (31).

Further, after the time t _P from the generation of the sampling pulse SP _1, the crosstalk between the pilot signals P _B1 and P _B2 of the adjacent track (5A ₁ ) on the tape transfer direction side is detected by the envelope detection circuit (29) by the differential amplifier (31). Is supplied to the other input end as a tracking signal with a delay phase. Therefore, the differential amplifier (31) sequentially compares the tracking signals corresponding to the crosstalk of the pilot signals P _B3 and P _B1 and P _B4 and P _B2 , respectively.

Then, the comparison error signal from the differential amplifier (31) is supplied to the sampling and holding circuit (32), and is generated from the sampling pulse generating circuit (39) after time t _P from the time when the sampling pulse SP ₁ is generated. Sampling is performed by a sampling pulse SP ₂ as shown in FIG. 5H. 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 the capstan motor (not shown) from the output terminal (33) to output the tape control signal. The transfer amount is controlled so that the level difference between both inputs to the differential amplifier (31) is zero, that is, the head (1B) moves to the track (5).
When scanning B ₁ ), the two tracks (5A ₂ ) and (5A ₁ ) on both sides are controlled so as to span 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 tracks, for example, when the head (1A) scans the track (5A ₂ ),
Crosstalk between the pilot signals P _A3 , P _A4 and P _A1 , P _A2 of the tracks (5B ₂ ) and (5B ₁ ) on both sides of the track can be obtained. Therefore, these are sampled and held by the sampling pulse generation circuit (38) as described above. The sampling pulse SP ₁ supplied to the circuit (30) samples the crosstalk of the pilot signals P _A3 and P _A4 to obtain a tracking signal, which is supplied to the differential amplifier (31) in the next stage and the pilot signal P The output from the envelope detection circuit (29) corresponding to the crosstalk of _A1 and P _A2 is supplied, and the tracking signals corresponding to the crosstalk of the pilot signals P _A3 and P _A1 and P _A4 and P _A2 are supplied here. The head (1A) is compared by comparing and the comparison error signal is sampled by the sampling pulse SP ₂ supplied to the sampling and holding circuit (32).
Tracking control signal can be obtained.

Similarly, when the head (1B) scans the track (5B ₂ ), as shown in FIG. 3, the pilot signals P _B5 and P _B6 of the tracks (5A ₃ ) and (5A ₂ ) on both sides of the head (1B) are scanned. And P _B3 , P _B4 cross talk is obtained, the cross talk of pilot signals P _B5 , P _B6 is sampled by sampling pulse SP ₁ and the pilot signal is output by the differential amplifier (31).
By comparing the tracking signals corresponding to the crosstalk of P _B5 and P _B3 , P _B6 and P _B4 respectively, and finally sampling the comparison error signal with the sampling pulse SP ₂ ,
A tracking control signal for the head (1B) can be obtained.

Similarly, when the head (1A) scans the track (5A ₃ ), as shown in FIG. 3, the pilot signals P _A5 and P _A6 of the tracks (5B ₃ ) and (5B ₂ ) on both sides of the track (5A ₃ ). And the crosstalk between P _A3 and P _A4 is obtained, the crosstalk between the pilot signals P _A5 and P _A6 is sampled with the sampling pulse SP ₁ , and the differential amplifier (31)
By controlling the tracking signals corresponding to the crosstalk of P _A5 and P _A3 , P _A6 and P _A4 respectively, and finally sampling the comparison error signal with the sampling pulse SP ₂ ,
A tracking control signal for the head (1A) can be obtained.

On the other hand, in the special playback mode such as after recording, the signal of a higher level from the terminal (45) is the AND circuit (4
3), the AND circuit (43) opens the gate, and the switch circuit (44) connects the fifth circuit from the delay circuit (41).
It is controlled by signal S ₂₁ as shown in FIG. That is, the switch circuit (44) is connected to the contact a side when the signal S ₂₁ is at the low level, and the switch circuit (44) is connected to the second side like the normal reproduction mode.
Sampling pulse SP ₂ of the first sampling pulse S
Although it is delayed by time t _P from P _{1 and the} crosstalk of the pilot signal of the adjacent track is sampled by the sampling hold circuit (32), when the signal S ₂₁ is at a high level, it is connected to the contact b side, normal reproduction mode and different second sampling pulse SP ₂ a first additional time than the sampling pulse t _P only words 2t _P only pilot signal itself sampling hold circuit of the track being scanned is generated by delaying (32) To sample.

Now, for example, if the head (1B) scans the track (5B ₁ ), the head (1B) will move to the area A _{T1 as} shown in FIG.
, The pilot signal P of both adjacent tracks (5A ₂ )
The pilot signal P _{B1 of B3} and the track (5A ₁ ) and the pilot signal P _A1 of the track (5B ₁ ) are reproduced. At this time, the reproduction output of the head (1B) from the switch circuit (27) is supplied to the narrow band pass filter (28) having the pass center frequency f ₀ , and as its output S _A as shown in FIG. 5D. As for the pilot signal, only the pilot signal is taken out and supplied to the envelope detection circuit (29).

In addition, the output S _R of the switch circuit (27) is a narrow band pass filter (34) whose pass center frequencies are f ₁ and f ₂ , respectively,
Is supplied to (35) and its output side is shown in FIGS. 5E and 5F, respectively.
Positioning signals S ₁₀ and S ₁₁ as shown in FIG.
These signals S ₁₀ and S ₁₁ are supplied to the switch circuit (36). When the switching signal S ₁ ′ is low level, the signal S ₁₀ is extracted, and when it is high level, the signal S ₁₁ is extracted and compared. Supplied to the vessel (37).

The comparator (37) compares the supplied signals S ₁₀ and S ₁₁ with a reference value to perform waveform shaping, and a sampling pulse generation circuit (3
Supply to 8) and (39). The sampling pulse generation circuit (38) generates a first sampling pulse SP ₁ as shown in FIG. 5G at the rising edge of the waveform-formed signal S ₁₀ , and this sampling pulse SP ₁ is supplied to the sampling hold circuit (38). 30). At this time, the sampling pulse SP ₁ is shown by the arrow (4
T) (FIG. 3) shows a state in which the crosstalk of the pilot signal P _B3 of the adjacent track (5A ₂ ) on the side opposite to the transfer direction is sampled, and this sampled signal is differentiated as a lead phase tracking signal. It is supplied to one input terminal of the amplifier (31).

Further, after the time 2t _P from the generation of the sampling pulse SP ₁ , the pilot signal P _A1 of the track (5B ₁ ) being scanned is delayed by the envelope detection circuit (29) to the other input terminal of the differential amplifier (31). It is supplied as a tracking signal. Therefore, the differential amplifier (31) receives the pilot signals P _B3 and P _B3.
The tracking signals corresponding to _A1 are compared.

Then, the comparison error signal from the differential amplifier (31) is supplied to the sampling and holding circuit (32), and is generated from the sampling pulse generating circuit (39) 2 t _P after the time when the sampling pulse SP ₁ is generated. Figure I
It is sampled by the sampling pulse SP ₂ as shown in. 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 the capstan motor (not shown) from the output terminal (33) to output the tape control signal. The transfer amount is controlled so that the level difference between both inputs to the differential amplifier (31) becomes a certain negative value.
In the area A _T2 , the pilot signal P _A2 of the track (5B ₁ ) and the pilot signal P _{B4 of both} adjacent tracks (5A ₂ )
And the pilot signal P _B2 of the track (5A ₁ ). At this time, the reproduction output of the head (1B) from the switch circuit (27) is supplied to the narrow band pass filter (28) having the pass center frequency f ₀ , and as its output S _A as shown in FIG. 5D. As for the pilot signal, only the pilot signal is taken out and supplied to the envelope detection circuit (29).

In addition, the output S _R of the switch circuit (27) is a narrow band pass filter (34) whose pass center frequencies are f ₁ and f ₂ , respectively,
Is supplied to (35) and its output side is shown in FIGS. 5E and 5F, respectively.
Positioning signals S ₁₀ and S ₁₁ as shown in FIG.
These signals S ₁₀ and S ₁₁ are supplied to the switch circuit (36). When the switching signal S ₁ ′ is low level, the signal S ₁₀ is extracted, and when it is high level, the signal S ₁₁ is extracted and compared. Supplied to the vessel (37).

The comparator (37) compares the supplied signals S ₁₀ and S ₁₁ with a reference value to perform waveform shaping, and a sampling pulse generation circuit (3
Supply to 8) and (39). The sampling pulse generation circuit (38) generates a first sampling pulse SP ₁ as shown in FIG. 5G at the rising edge of the waveform-formed signal S ₁₀ , and this sampling pulse SP ₁ is supplied to the sampling hold circuit (38). 30). At this time, the sampling pulse SP ₁ is shown by the arrow (4
T) (FIG. 3) is in a state of sampling the crosstalk of the pilot signal P _B4 of the adjacent track (5A ₂ ) on the opposite side to the transfer direction, and this sampled signal is differential as a lead phase tracking signal. It is supplied to one input terminal of the amplifier (31).

Further, after time t _P from the generation of the sampling pulse SP ₁ , crosstalk of the pilot signal P _B2 of the adjacent track (5A ₁ ) on the tape transfer direction side is detected by the envelope detection circuit (29).
It is then supplied to the other input terminal of the differential amplifier (31) as a tracking signal with a delay phase. Therefore, the differential amplifier (31) compares the tracking signals corresponding to the crosstalk between the pilot signals P _B4 and P _B2 , respectively.

Then, the comparison error signal from the differential amplifier (31) is supplied to the sampling and holding circuit (32), and is generated from the sampling pulse generating circuit (39) after time t _P from the time when the sampling pulse SP ₁ is generated. The sampling pulse SP ₂ shown in FIG. 5I is used for sampling. 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 the capstan motor (not shown) from the output terminal (33) to output the tape control signal. The transfer amount is controlled so that the level difference between both inputs to the differential amplifier (31) becomes a certain positive value (the above-mentioned certain negative value and the absolute value are substantially equal). Controlled.

Therefore, when the head (1B) scans the track (5B ₁ ), the center position in the width direction of the gap of the head (1B) corresponds to the combined value of the tracking error signals in the areas A _T1 and A _T2 . Control is performed so that scanning is performed by offsetting a predetermined amount, for example, 45 ° on the track (5A ₂ ) side in a predetermined direction from the center position of 5B ₁ ).

The same applies to other tracks, for example, when the head (1A) scans the track (5A ₂ ),
The crosstalk of the pilot signals P _A3 , P _A4 and P _A1 , P _A2 of the tracks (5B ₂ ) and (5B ₁ ) on both sides thereof can be obtained, and the pilot signals P _B3 , P _B4 of the track being scanned can also be obtained. From the sampling pulse generator (38) to the sampling hold circuit (30) by the sampling pulse SP ₁ supplied to the pilot signals P _A3 and P _A4.
Crosstalk is sampled to obtain a tracking signal, which is supplied to the differential amplifier (31) in the next stage, and the crosstalk of pilot signal P _A1 and pilot signal P _B4
The output from the envelope detection circuit (24) corresponding to is supplied, the tracking signals corresponding to the pilot signals P _A3 and P _A1 , P _A4 and P _B4 are compared, and the comparison error signal is sampled and held. A tracking control signal for the head (1A) can be obtained by sampling with the sampling pulse SP ₂ supplied to the circuit (32).

Similarly, when the head (1B) scans the track (5B ₂ ), as shown in FIG. 3, the pilot signals P _B5 and P _B6 of the tracks (5A ₃ ) and (5A ₂ ) on both sides of the head (1B) are scanned. And P _B3 , P _B4 crosstalk is obtained, and pilot signals P _Aa , P _A4 of the track being scanned are also obtained, so the crosstalk of pilot signals P _B5 , P _B6 is sampled with sampling pulse SP ₁ and the difference The dynamic amplifier (31) compares the tracking signals corresponding to the pilot signals P _B5 and P _A3 and P _B6 and P _B4 , respectively, and the comparison error signal is finally sampled by the sampling pulse SP ₂ so that the head ( The tracking control signal for 1B) can be obtained.

Similarly, when the head (1A) scans the track (5A ₃ ), as shown in FIG. 3, the pilot signals P _A5 and P _A6 of the tracks (5B ₃ ) and (5B ₂ ) on both sides of the track (5A ₃ ). And P _A3 and P _A4 are obtained, and the track pilot signals P _B5 and P _B6 during scanning are also obtained. _Therefore , the cross talk of the pilot signals P _A5 and P _A6 is sampled by the sampling pulse S.
Sampled at P _1, a differential amplifier (31), and controls the respective corresponding tracking signal to the pilot signal P _A5 and P _A3, P _A6 and P _B6, the comparison error signal finally sampling pulse SP ₂ By sampling the head (1
A tracking control signal for A) can be obtained.

Then, in the special playback mode, for example, in the case of after-recording, when it comes to a portion to be recorded, for example, a subcode (on both sides of the areas A _T1 and A _T2 (not shown)), the recording mode is set and the recording is rewritten. Is done.

FIG. 6 shows the S curve characteristics in the areas A _T1 and A _T2 when the track (5B ₁ ) is typically scanned by the head (1B) in the special reproduction mode as described above. ) Scans the area A _T1 with the crosstalk of the pilot signal P _B3 and the pilot signal P _A1.
Is detected, and the S curve characteristic shown by the solid line a in FIG. 6 is obtained, while the area A is detected by the head (1B).
By scanning _T2 , the crosstalk between the pilot signals P _B4 and P _B2 is detected, and the S curve characteristic shown by the solid line b in FIG. 6 is obtained.

Therefore, when the head (1B) scans the track (5B ₁ ), S as shown by the solid line c obtained by combining the characteristics of the solid lines a and b
Tracking control is performed according to the curve characteristics. That is, the head (1B) scans the track (5B ₁ ) with an offset of 45 ° (to the track (5A ₂ ) side) from the normal reproduction mode.

Although FIG. 6 shows the case where azimuth loss is not taken into consideration, the output characteristic when azimuth loss is taken into consideration can be expressed as shown in FIG. 7, and the track in which the pilot signal P _B3 or the like from the adjacent track is being scanned. It can be seen that the output level is lower than the pilot signal P _A1 from. In FIG. 7, a solid line a represents an actual S curve characteristic obtained by combining S curve characteristics of 0 ° and 90 °, and a solid line b represents an ideal combined S curve characteristic. The offset deviates slightly from 45 ° from the actual S-curve characteristics, but this is not a problem for practical use.

FIG. 8 shows changes in the tracking error signal obtained at the output terminal (33) when the special reproduction mode is set as described above. FIG. 8A shows, for example, when after-recording a predetermined area at both ends of the track. 7 shows changes in the tracking error signal of the output terminal (33) corresponding to the above-described detection outputs in the areas A _T1 and A _T2 (lower part of FIG. 8A).

Further, such after-recording may be performed at only one place. In that case, it is preferable to use the tracking control area on the side closer to the after-recording portion. Figure 8 B is intended to indicate a case of after-recording of the predetermined region on the side of the region A _T1, an output terminal (3 corresponding to the detected output in the region A _T1 at this time
It can be seen that the tracking error signal obtained in 3) changes as shown in the lower part of FIG. 8B and is almost the same as in the case of after recording at two locations.

FIG. 9 shows an example of a concrete circuit configuration of the sampling pulse generating circuit (39). In FIG. 9, (40) is the wave number (pulse) of the position finding signal supplied from the comparator (37). The counter (41) counts the contents of the positioning signal in response to the signals S ₂₀ , S ₁ ′ obtained by delaying the signal S ₄ by the time T, that is, in the present embodiment, the respective frequencies of the positioning signals S, T and 4 types of data (set values) classified by recording length
Is a data selector for selecting, and (42) is a match detection circuit for detecting a match between the count value of the counter (40) and the data of the data selector (41).
For example, a digital comparator is used.

(43) to (46) are delay circuits that generate 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).
It is designed to be cleared by the output of the delay circuit (45). (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 CK
The sampling pulse SP ₁ is substantially applied to the reset terminal R via the delay circuit (46), and the output of the delay circuit (45) is supplied to the reset terminal R thereof.

Reference numeral (48) is a gate circuit such as an AND circuit. The output of the delay circuit (43) is supplied to one input terminal of the AND circuit (48) and the flip-flop circuit (47) is supplied to the other input terminal. The output of the output terminal Q is supplied, and the sampling pulse SP ₂ is output from the output terminal thereof.

Next, the circuit operation of FIG. 9 will be described with reference to the signal waveforms of FIG. Note that FIG. 10 shows one rotation on the right side of FIG. 5, that is, an even numbered rotation period.

Now, the signal S ₁₃ as shown in FIG. 10D, which is a positioning signal from the comparator (37), is generated by the sampling pulse generating circuit (3
8), the sampling pulse generating circuit (38) synchronizes the first pulse of the signal S ₁₃ with the first pulse.
A sampling pulse SP ₁ as shown in FIG. 0H is generated.
The sampling pulse SP ₁ is supplied to the above-mentioned sampling hold circuit (30) (FIG. 1) and also to the delay circuits (43) to (46).

The delay circuit (44) is connected to the output side of the delay circuit in synchronization with the sampling pulse SP _1. The signal S ₁₂ as shown in FIG. 10C having a considerable duration.
And the signal S ₁₂ is supplied to the counter (40) as an enable signal.

Counter (40) is the signal S ₁₂ a high level period comparator (3
Count the pulses of signal S ₁₃ from 7). On the other hand, the data selector (41) outputs the signals S ₁ ′ and
In response to S ₂₀ , select the data associated with the position location signal. When the selected data and the contents of the counter (40) match, the match detection circuit (42) outputs to its output side as shown in FIG. 10E, which lasts for a predetermined time after the trailing edge of the final pulse of the signal S ₁₃ . Signal S ₁₄ is generated, and this signal S ₁₄ is supplied to the flip-flop circuit (47) as data.

The delay circuit (46) synchronizes with the sampling pulse SP ₁ and, after a predetermined time Δt ₁ from this, outputs the signal S as shown in FIG. 10F.
₁₅ is generated, and this signal S ₁₅ is generated by the flip-flop circuit (4
The signal S ₁₄ supplied to the clock terminal CK of 7) and supplied to the input terminal D is latched. The delay time (46)
The delay time Δt ₁ at It is said that

Also, the delay circuit (45) generates a signal S ₁₅ as shown in FIG. 10G after a predetermined time Δt ₂ in synchronization with the sampling pulse SP ₁ , and this signal S ₁₅ is supplied to the counter (40). The contents are cleared and supplied to the flip-flop circuit (40) to be reset. As a result, the signal S ₁₇ as shown in FIG. _10I is generated at the output side of the flip-flop circuit (47). The delay time Δt ₂ in the delay circuit (47) is Δt ₂ > t _P.

The delay circuit (43) 'generates _S, the signal S' signal S as shown in FIG. 10 J than this in synchronism with the sampling pulse SP ₁ after the predetermined time t _{P S} is an AND circuit (48) Is supplied to one of the input terminals.

Since the signal S ₁₇ formed as described above is supplied to the other input terminal of the AND circuit (48), this signal S _17
17 substantially opens the AND circuit (48) as a gate signal gate and the sampling pulse SP ₂ shown in FIG. 10 K in response to the signal S _'S is generated. Then, this sampling pulse SP ₂ is applied to the sampling hold circuit (3
2) Supplied to.

In this way, the sampling pulse SP ₂ can be generated.

It should be noted that this sampling pulse SP ₂ can also be generated by a process 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), step (b)
In short, this detects the position finding signals S and T, and if not detected, the operation is repeated. When detected, the first sampling pulse SP ₁ is generated based on the position-finding signals S and T in step (c), and the wave number (pulse) is generated only in the detection section of the position-finding signal S and T in step (d). ) Measure Ni.

Go to step (e), and detect position detection signals S, T
Is in the playback mode and determines whether the first one is generated, and if it is the first one, go to step (f), Section or When the section (1) is judged and either of them is satisfied, the second sampling pulse SP ₂ is generated in step (g). In step (f) Section or If the interval is not satisfied, the signal is not a position-locating signal, and the process returns to step (b).

In step (e), if the position-finding signal is generated after the second time in the reproduction mode, the process proceeds to step (h), and it is determined whether the polarity of the signal S ₂₀ has changed. If the polarity of signal S ₂₀ has changed, step (re)
And the last detection section is Determine which of the If so, the current position detection signal is Whether or not If so, it is a true positioning signal, so step (g)
Generate a _second sampling pulse SP ₂ at If not, return to step (b).

In step (re), the last detected section If so, go to step (l) and the current position detection signal is Whether or not If so, it is a true positioning signal, so step (g)
Generate a _second sampling pulse SP ₂ at If not, return to step (b).

This step (h)-(l) is explained in Fig. 5E, F and L.
Will be described in detail. If it is determined in step (h) that the polarity of the signal S ₂₀ has changed in the central portion on the right side of FIG. 5L, for example, S _{A4 of the} signal S ₁₀ shown in FIG. Is determined, Therefore, go to step (nu). And here at 5th
T _{B5 of the} signal S ₁₁ shown in FIG. Whether or not Therefore, the second sampling pulse SP ₂ is generated in step (g). At the step (nu), the signal T _B5 If not, return to step (b).

Also, in step (ri) If so, it is determined that it is the signal S _A6 (not shown) instead of the signal S _A4 of the signal S ₁₀ (therefore, the time when the polarity of the signal S ₂₀ changes is not the center portion on the right side of FIG. In the step (L), T _B7 (not shown) of the signal S ₁₁ shown in FIG. I'm not sure) Therefore, the second sampling pulse SP ₂ is generated in step (g). Signal T at step (Le)
_B7 If not, return to step (b).

Now, if the polarity of the signal S ₂₀ has not changed in step (h), go to step (wo), judge whether the detection section is the same as the previous positioning signal, and if the same, step (w) 2) Sampling pulse SP ₂
To occur. Referring to FIG. 5E, for example, the first S _A1 and the second S _A2 of the positioning signal S ₁₀ are the same. Therefore, 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 over an angle range narrower than the head angle interval to record / reproduce, but the tape is wound in the same angle range as the head angle interval as usual. Needless to say, the present invention can be applied to the case of using the rotary head device.

〔The invention's effect〕

As described above, according to the present invention, tracking control is performed by detection output of pilot signals from both adjacent tracks in a plurality of recording areas in the normal reproduction mode, and pilots from both adjacent tracks in one recording area in the special reproduction mode. The detection output of the signal, that is, the 0 level of the detection output passes through 0 °. The characteristic and the detection output of the pilot signal from the adjacent track and the track being scanned in the other recording area, that is, the 0 level of the detection output passes through 90 °. Since the tracking control is performed by offsetting a predetermined amount from the normal reproduction mode by the combined detection output with the S-curve characteristic, even if there are variations in track bending, tape, head sensitivity, etc. You can give an offset, for example, in the case of after recording, It is possible to reliably set the set amount.

[Brief description of drawings]

FIG. 1 is a circuit configuration diagram showing an embodiment of the present invention, FIG. 2 is a diagram showing an example of a rotary head device used in FIG. 1,
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. 1, and FIG. 5 is for explaining the reproducing operation in FIG. 6 to 8 are diagrams for explaining the present invention, FIG. 9 is a circuit configuration diagram showing an example of an essential part of the present invention, and FIG. 10 is a diagram in FIG. FIG. 11 is a signal waveform diagram for explaining the operation, and FIG. 11 is a flow chart for explaining the operation for generating the second sampling pulse. (1A) and (1B) are rotary magnetic heads, (2) is magnetic tape,
(6) is a pilot signal oscillator, (7) is a positioning signal oscillator, (9) is an erasing signal oscillator, (10),
(11), (12), (13) are recording waveform generating circuits, (21),
(40), (41), (42) are delay circuits, (22), (23),
(24), (25) are recording timing generation circuits, (28),
(34) and (35) are bandpass filters, (29) is an envelope detection circuit, (30) and (32) are sampling and holding circuits, (31) is a differential amplifier, and (36) and (44) are switch circuits. , (37) are comparators, (38), (39) are sampling pulse generating circuits, and (43) is an AND circuit.

Front page continued (72) Inventor Makoto Yamada 6-735 Kita-Shinagawa, Shinagawa-ku, Tokyo Sony Corporation (72) Shinji Miyamori 6-35 Kita-Shinagawa, Shinagawa-ku, Tokyo Sony Corporation Shares In-house (72) Inventor Takashi Omori 6-735 Kitashinagawa, Shinagawa-ku, Tokyo Inside Sony Corporation

Claims (1)

[Claims] 1. A digital signal recorded on an oblique track formed on a tape-shaped recording medium by a plurality of rotary heads and a plurality of recording areas independent of the digital signal on each track. In order to reproduce the signal on the track in a digital signal reproducing device for reproducing a tracking pilot signal and a position-finding signal having a frequency different from the pilot signal recorded near the center of the pilot signal on an adjacent track. A scanning head having a scanning width wider than the track width, digital signal reproducing means for reproducing the digital signal from the signal reproduced by the rotating head, and reproducing the positioning signal from the signal reproduced by the rotating head. Position-positioning signal reproducing means for A pulse signal forming means for forming a pulse signal is compared with the level of the pilot signal reproduced from adjacent tracks on both sides in one recording area according to the pulse signal in the after recording mode, and in the other recording area. The rotary head comprises: comparing means for comparing the levels of the pilot signals reproduced from the adjacent track and the track being scanned and outputting a comparison error signal; and means for performing tracking control of the rotary head by the comparison error signal. The digital signal reproducing apparatus is characterized in that the scanning is performed by offsetting the recording track by a predetermined amount.