JPS59203206A - Recording method of pcm signal - Google Patents

Abstract

PURPOSE:To facilitate the detection of a pilot signal for tracking control and the interpolation processing of a dropped-out signal at a reproducing time by recording this pilot signal in an area, which is different from an area where a PCM signal should be recorded, of the same track as the PCM signal. CONSTITUTION:The pilot signal for tracking control is recorded in the first area AT1 of every other track TA, and the pilot signal for tracking control is recorded in the second area AT2 of every other track TB. At a normal reproducing time, levels of pilot signals from areas AT2 of both adjacent tracks TB are equalized with respect to a head HA when the corresponding track TA is scanned. Levels of pilot signals from areas AT1 of both adjacent tracks TA are equalized with respect to a head HB when the track TB is scanned. The pilot signal is recorded in the area different from that of the PCM signal in this manner to detect and erase easily the pilot signal at a reproducing time.

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 converts this signal into a PCM signal on a tape by a rotary head, for example, on a tape, one diagonal track at a time. The present invention relates to a recording method, and in particular to a method for achieving good tracking control of a rotary head during reproduction.

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 PCM allows recording and reproduction with high surface quality.

In this case, the rotating head should correctly scan the recording trunk when writing typeface (ranking control is
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 this reproduction control signal and the rotational phase of the rotary head have a constant phase relationship. Usually, this is done depending on the situation.

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

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

Therefore, the following method was considered to perform tracking control without using this fixed head.

This method, for example, forms trunks TA and 'rB in a so-called overwritten state (without forming guard hands between tracks) by using two rotary heads with different extension directions in the width direction of the gaps to write analog video signals. ) This is for recording and reproducing (see Fig. 1), and a pilot signal for trunking is recorded on the trunk in which the video signal is recorded by means of a rotary head that receives the video signal. In this case, the pilot signal is a signal on the low frequency side where no recorded signal of the ζ video signal exists in the frequency range, so that it can be easily separated during playback, and 1. The frequency of this pilot signal is made to differ between adjacent tracks, for example, the frequency f A of 4 complements 1 = 100kllz.

f 5-115kH2, f c = 160ktlz,
f o -145kHz is used.

During playback, when the tracking servo and the rotary head HB, which have a gap width wider than the track width, scan the trunk that should originally be scanned, as shown in FIG.
This is done by scanning parts of the trunks on both sides of the trunk by the same amount. In other words, since the frequency of the pilot signal is low as mentioned above, there is almost no azimuth loss, so the pyro and soto signal components can be extracted from the reproduced signals from the adjacent tracks on both sides, and the level of the pilot signals from these adjacent tracks can be extracted. Tracking control is performed so that these are equal.

In the case of the above method, since a low frequency signal is used as the viroft signal, new recording is performed over the previously recorded part while erasing it. This prevents the inconvenience that the previous signal remains when performing the When the information signal has a spectrum in the low frequency band, such as a PCM signal, it is difficult to separate the pilot signal. Furthermore, since four types of frequencies are used as pilot signals, there is also the drawback that the configuration becomes complicated.

Furthermore, when considering tracking control in a rotary head type recording and reproducing apparatus, it is necessary to consider not the case of normal repeating, but the case of variable speed reproduction in which the tape speed is different from that during recording.

During playback (if the tape speed is the same normal speed as during recording, the scanning direction of the rotating head on the tape and the longitudinal direction of the recording track 7 will match, and I80
Two rotating heads I with different azimuth angles separated by an angle of °
The IA, 118 can be tracked and controlled to constantly scan the corresponding recording trunk TA, TB. Therefore, the font output is as shown in Fig. 3. For each tape contact period PA and PB of each head HA and IIB, a signal sA from the track TA and a signal SB from the trunk TB are generated.
are obtained alternately and sequentially.

However, when the tape speed is increased to N times for N times speed playback, if the rotation speed of the rotary head is not changed, the scanning direction of the rotary head on the tape will be different from the longitudinal direction of the recording trunk, and adjacent tracks will be Furthermore, the rotary head will be able to scan across multiple trunks. especially,
As mentioned above, in the case of a recording/reproducing device that uses rotary heads with different azimuth angles for recording at the same density, the problem is how to scan the rotary head over the recording track pattern during variable speed reproduction when azimuth loss is taken into account. Become. Basically, it is conceivable to increase the information M of the reproduced signal by scanning one trunk recorded with a head having the same rotation Δ and the same azimuth angle as long as possible. For example, in the case of double speed playback, the rotating head gear
The center position of 11 is the solid line +ll, f2L in Figure 2.
F3). In other words, two with different azimuth angles
This is because when two rotary heads are used, the recording heads are different between the trunk TA and the trunk TB, and if scanning is performed with a head having a different azimuth and angle from that used during recording, a reproduced signal cannot be retrieved due to azimuth loss.

However, during double speed playback, every other recording track is scanned as shown in FIG. 2, so if one head 11^ is controlled to scan the corresponding recording trunk TA,
The other head IIB also scans this trunk TA every time, and as shown in FIG. 3B, no reproduction signal can be obtained during the scanning period PB of this head 'llB. If no reproduction signal is obtained from one trunk in this way, signal processing during reproduction becomes difficult.

Particularly in the case of PCM signals, one track is generally regarded as one segment, and the signal processing within the range of this one segment's data is often performed, and it is said that the data for this one segment cannot be obtained. This means that there is no signal at all during that period.

In the case of video signals, if one segment is set as one field, a certain degree of clustered image can be obtained by using vertical correlation and filling in the missing part with the previous signal, but in the case of audio signals, such correlation The sound is difficult to hear because it has no character at all.

Therefore, a scanning method is developed in which the center of the gap width of the rotary head passes through the position shown by the dashed-dotted lines (41 (5) (61) in FIG. One of the two adjacent recording trunks TA, TB formed by the heads, for example, trunk T4., is scanned in the first half of the tape contact period of each rotary head) IA, IIB, and the other, for example, trunk TB, is scanned in the second half. It is intended to do so.

In this way, during the tape contact periods PA and PB of each rotary head HΔ, HB, the reproduction signal can be extracted during the scanning period of the corresponding trunk as shown in FIG. During this period, the signal never disappears.

As mentioned above, in the case of a PCM signal, the signal is processed in units of one trunk at the time of recording, and interleaving to strengthen against burst errors is also performed within the range of one trunk. Therefore, in FIG. 3C, although it appears that the same signal loss period as in FIG. 3B occurs in terms of time, when the PCM signals obtained in each period PA and PB are decoded , the data at the point in time distributed between each period of periods PA and PR can be obtained.If you use this reproduced data and perform signal processing such as interpolation on the missing data, the audio Even in the case of a signal, relatively easy-to-listen reproduced sound can be obtained.

The first object of the invention is to record a biloft signal when recording a PCM signal and a pilot 1 bit signal so that tracking control of the rotary head can be performed using only the playback output of the rotary head. It is an object of the present invention to provide a recording method which allows easy erasure and separation of data from the reproduction number 4m, and which simplifies the configuration of an apparatus 6'.

A second object of the present invention is that when a plurality of rotary heads with different azimuth angles are used, the rotary head can be moved to a scanning position as shown by the dashed lines (41(5) and (6) in FIG. 2), especially during double-speed playback. It is an object of the present invention to provide a recording method that can be used to record images.

Summary of the invention PCM signals can easily be compressed and expanded on the time axis.

Therefore, unlike analog signals, it is not necessary to record and reproduce signals continuously in time. Therefore, by dividing the area into one trunk, this PCM signal and this separate area (
+1i1 signals can be easily recorded.

The present invention utilizes this fact, and records the Pi-Nissan-So1 signal for tracking control as the above-mentioned separate signal, and devises the manner in which the pilot signal is recorded.

In the present invention, as shown in FIG. 4, each track TA, T8, TA, T8... has first and second recording areas spaced from the center position 0 in the longitudinal direction by an equal distance β. ATi and ^T2 are used for tracking control separately from the PCM signal recording area AS.

Then, in the first area 1 construction indicated by diagonal lines in FIG. 4, a tracking pilot signal is recorded in every other track TA of T1, and In the second area AT2, this area A
A tracking pilot signal is recorded in every other remaining trunk TB of T2.

In this way, during normal playback, when the head 118 scans the corresponding trunk TA, the pilot signal output levels from the areas AT2 of the tracks TB on both sides of the head 118 are equal, as shown in the figure. In addition, when scanning the track TB (head) IB, trunking control is performed so that the pilot signal output levels from the areas ATL of the adjacent tracks TA on both sides are equal as shown in the figure. It can be done.

During double-speed playback, during the tape contact period of each rotary head, the pilot signal output level from the area ATt of the trunk TA and the pilot signal output level from the area ΔT2 of the adjacent track 1'B. By controlling the speed so that they are equal to each other, it is possible to achieve the desired trunking state in the case of double speed, as shown by the solid line (7) in FIG.

In this case, the difference between the pilot signal output level from the area ATi of the truck TA and the pilot signal output level from the area AT2 of the trunk TB is plotted on the vertical axis, and the shift in the trunking position is calculated according to the pattern diagram in FIG. When plotted on the horizontal axis, it is represented as a box in FIG. From this figure 5, the tracking position at double speed is not only 0" but also ±
It can be seen that the position may be shifted by 180°. but,
Depending on the drive direction of the drum motor for driving the rotary head or the capstan driving morph, the stable point is either the ζO'' position or a position deviated by 180°.

In this way, since the tracking river pilot can be recorded and reproduced completely independently of the PCM signal, a signal that is easy to erase can be used as the pilot signal, and the pilot signal can be easily extracted during reproduction.

Further, as described above, it is possible to set the rotary head at an optimal tracking position during double speed reproduction.

Note that although FIG. 4 is a diagram in which the recording tracks are formed perpendicularly to the longitudinal direction of the tape, this diagram is for illustration only, and when the recording tracks are oblique to the longitudinal direction of the tape, It is easy to understand that the above can be applied as is.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to the drawings.

The following example is a case where there are two rotating magnetic heads and the following rotating head device is used.

First, to explain this rotating magnetic head device, as shown in FIG.
) are arranged at equal angular intervals, that is, at 180 degree angular intervals. On the other hand, the magnetic tape (12) is connected to the tape guide drum (
13) narrower than its 180 degree angular range of the circumferential surface of
Wraps over 0 degree angle range. Then, the rotating heads (IIA) and (IIB) are rotated at a rate of 30 revolutions per second in the direction of the arrow (1511), and the tape (12) is run at a predetermined speed in the direction shown by the arrow (15T). and rotating head (118) and (IIB)
As a result, diagonal magnetic tracks (14A) (14B) are formed on the magnetic tape (12) as shown in FIG.
) are formed in a so-called overwritten state. That is, the head gap width (scan 'l'
l+1) W is set to be larger than the track width. In this case, the width directions of the gaps between the heads (11Δ) and (IIB) 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.

According to the above rotary head device, the period during which the 2 (+61 rotary heads (11Δ) CIIB) do not abut against the tape (12) together (this is the period of the 90 degree angular range bone in this example) If this period is used to add redundant data during recording and perform correction processing during playback, the apparatus can be simplified.

In this case, each track (1
48) Divide (14B) into a PCM signal recording area and a 1-racking signal recording area. In this example,
T1 and Ar1 are provided in the recording area for trunking signals at both ends of each trunk (14A) (14B) in the longitudinal direction at a distance of 111i72 geometrically from the longitudinal center position of each trunk (14A) (14B). In addition, each trunk (14A) (14
T3 is also provided in the center part of B > in the recording area of the tracking signal. The recording areas for the PCM signal are the remaining areas AS1 and AS2.

The pilot signal and PCM signal for tracking control are recorded in these recording areas 9J4 area 8Ts, ^T2 + 8T3, 8St, and 8S2 as follows.

The following example will be explained using a case where an audio signal is recorded in PCM format.

FIG. 8 and FIG. 9 are diagrams for explaining an example thereof.

Figure 8 shows an example of the recording system, in which the audio signal SA is sent to the A/D converter (21) through the input terminal (21).
22) and converted into a digital PCM signal. This digital signal is supplied to a recording encoder (23).

In this recording encoder (23), a signal to be recorded as one track (referred to as a signal for one segment)
, that is, in this example, the rotating head (11Δ) (IIB
) is time-compressed to a period slightly shorter than the tape contact period of the head, and also generates and adds an error correction code, interleaves within one segment range, etc. It will be done. The output signal of the recording encoder (23) is supplied to the recording processor (24), where a block synchronization signal, address data, etc. are added to each block of multiple words, and the signal is modulated into a signal suitable for recording and reproduction. Ru. The PCM signal from this recording processor (24) passes through a switch circuit (25) for switching between the PCM signal recording area and the tracking area, and then passes through a head switching switch circuit (26).
). These switch circuits (26) and (25)
) is the switching signal S from the timing signal generation circuit (28)
z (FIG. 9A) and switching signal S2 (FIG. 9C). In this case, the timing signal generation circuit (28) is supplied with a signal indicating the rotational phase of the rotary heads (118) and (IIB). That is, in this example, the timing signal generation circuit (28
) is equipped with a pulse generator (17) head (118) (
A pulse PG of 30H7 is supplied without changing the rotational phase of the rotary head (118) (11B) which is 1# in synchronization with the rotation of the rotational drive motor (16) of IIB). Also,
3 from the pulse PC and timing signal generation circuit (28)
The pulse of 011Z is supplied to the phase servo circuit (29), and the rotational phase of the motor (16) is controlled by the servo output.

Therefore, °ζ, switching signals s1 and s2 are generated by the rotating head (I
It is synchronized with the rotation of IA) (IIB), and the 9th
As shown in FIG.
12), and the head (IIB) is in contact with the tape (12) within a half-rotation period tB during which the signal s1 is at a low level, and the signal S2 is in contact with the tape (12) in the back region ATz of each contact period. Ar1.

It is set to a high level during a period of length τ corresponding to Ar1. Then, the switch circuit (26) is switched by the switching signal S1 to the state shown in the figure during the period tA, and to the state opposite to the state shown in the figure during the period tA,
Head switching is performed.

Further, the switch circuit (25) is switched by the switching signal s2 to the state shown in the figure when the signal S2 is low level, and to the state opposite to the state shown when the signal S2 is high level. Therefore, the head (II
Since the switch circuit (25) is switched to the state shown in the figure except for the beginning τ period, the middle τ period, and the end τ period of the contact period of A) and (IIB), the switch circuit (26) The recording processor (2)
During period tA, the audio PCM signal for one segment from 4) is sent to the head (IIA) through the amplifier (27Δ).
and during period tB, it is supplied to the head (11B) through the amplifier (27B) to record the recording area ASt of each track (14A) and trunk (14B), respectively.
This is also recorded in AS2 (see Figure 9E).

The switch circuit (25) is switched to a state opposite to that shown in the figure at the beginning, end, and center of the contact period of each belly button t"<11A> and (1111). At this time, A state is reached in which a signal from the switch circuit (33) is supplied to the switch circuit (26) through this switch circuit (25).

This switch circuit (33) receives a bias signal P from an oscillator (31) with a heating frequency f and an oscillation frequency f.
A signal E for erasing the pilot signal P is supplied from the second oscillator (32), and is selectively switched by a switching signal %S3 from the timing signal generating circuit (28).

The signal P to Byron 1 has a frequency f1 with a relatively small value of azimuth loss, for example, 100kHz to 500kHz.
It is recorded at a relatively high level.

The erasing signal E ensures that when a new recording is made on a previously recorded tape while erasing the previously recorded information, the recording track always matches the previous recording track. This is used because it is necessary to erase the previously recorded pilot signal, since the frequency f2 is sufficiently far away from the frequency f1 for practical purposes, and the pilot signal P It is assumed that the value can be erased.

Further, the recording level is also set at a level that can practically erase the pilot signal P.

As shown in Figure 9, the switching signal S3 of the switch circuit (33) is at a high level only during the period tA at the beginning of the contact period of the head (11Δ) and during the period τ in the middle, and during the period tB, the switching signal S3 is at a high level. This signal becomes high level only during the period τ at the end of the contact period of IIB>, and the switch circuit (33) is switched to the pilot signal P side from the oscillator (31) only during this high level period. In this example, the high level period of the signal S3 is set to be the length period and the center of the period of length τ.

Therefore, in the middle period between the beginning and the middle period τ of the contact period of the head (IIA) within the period tA, the pilot signal P from the oscillator (31) is transmitted by the head (IIA) as shown in FIG. Every other track (14A)
) is recorded at the center position (shown with diagonal lines in the figure) of the recording areas ATI and Ar1.

Also, τ at the beginning and center of the contact period in LA during this period.
Since the switch circuit (33) is in the state shown in the figure except for the period t in period a and the period τ at the end, the oscillator (
32) The erasing signal E from 32) is shown in Figure 7.
"' (11Δ) is recorded before and after the pilot signal recording position in the recording areas ΔT1 and ΔT3 of the trunk (148), and is recorded over the entire recording area j5Ah (see FIG. 9E).

On the other hand, during the period τ between the beginning and the middle of the contact period of the head (IIB) within the period tB, the switch circuit (25) is switched to the switch circuit (33) side, but the switch circuit (33) is in the state shown in the figure. Therefore, during the initial period τ of the contact period of the head (IIB) within this period t8, the erasing signal E is switched to the head (IIB).
B) (see FIG. 9E), and as shown in FIG. 7, only this erasing signal E is recorded over the entire area ATz and Ar1 of the trunk (14B). Then, when the period τ at the end of this period tB comes, the switch circuit (33) is activated by the signal S3 during the middle period of the second period.
is switched to the opposite state to that shown in the figure, and 1-rack (
The pilot signal P is recorded in the central part of the recording area A'h of 14B) as indicated by diagonal lines in FIG.

In this example, the recording position of the pilot signal P is track (14A), as is clear from FIG.
(14B) are made so that they do not overlap each other when viewed from a direction perpendicular to the longitudinal direction. The technology for this is VTR
In this method, it is possible to apply a technique in which the recording positions of horizontal synchronizing signals of video signals are aligned in a direction perpendicular to the longitudinal direction of the track. In this example, when the positions of the ends of the human trunks between adjacent tracks (14Δ) (14B) differ by d in the longitudinal direction of the trunks, the area AT1+AT2, the length of Ar1 is 4d, and the length of Ar1 is 4d. The recording period is 2d.

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

Figure 10 shows an example of the regeneration system, in which a motor (not shown) is shown.
16), a drum phase search is applied in the same way as during recording.

The tape (
12) The signal extracted from the head amplifier (41A)
and (41B) to the switch circuit (42). This switch circuit (42) uses a 30Hz switching signal S1' from the timing signal generation circuit (28) to control the half-rotation period tA including the tape contact period of the head (IIA) and the period of the head (IIB) in the same manner as during recording. It is alternately switched with a half-rotation period tB including the tape contact period.

Therefore, from this switch circuit (42),
An intermittent PCM signal of one segment at a time is obtained, and this is supplied to a reproduction processor (43), demodulated to the original PCM signal, and this is supplied to a decoder (44). This decoder (44) detects data for each block based on the block synchronization signal, and also performs processing such as error correction and de-interleaf. The PCM signal from this decoder (44) is transferred to the D/A converter (45).
), where it is converted back into an analog audio signal and delivered to an output terminal (46).

Tracking control is performed as follows.

4. Next, normal playback will be explained.

Now, for example, the head (IIB) has a scanning width W including a track (14B) as shown by a dashed line in FIG.
, the head (IIB) scans across the tracks (14A) on both sides of this trunk (14B), and as shown in FIG. 148) pilot signal p;? i: Shosei zuru.

At this time, the head (IIB) from the switch circuit (42)
) is supplied to a narrow-band bandpass filter (51) with a passing center frequency fi, and only the pilot signal P is taken out, which is used in the detection stage II! The signal is supplied to fi (52) and detected, and the detected output is supplied to a sampling bold circuit (53). Then, the sampling and holding circuit (53) inputs "(sampler pulse 5P1 (11th Figure B) is supplied.Then, the first
As is clear from Figure 1A, this pulse SP1 is indicated by the arrow (1
5T>, the crosstalk of the pilot signal P of the adjacent trunk (14A) on the opposite side to the tape transport direction is sampled, and the sampling hold circuit (
548), the leading phase tracking signal STz
(FIG. 11D) is obtained.

This signal STs is used as a comparator circuit, which operational amplifier (54
) is supplied to the inverting input terminal of Also, the detection circuit (52)
The detected output of is supplied to the non-inverting input terminal of this operational amplifier (54). Therefore, the head (14B) is connected to the adjacent trunk (17 mm
During the period in which QP crosstalk (corresponding to a trunking signal with a delayed phase) is pink-amplified, the comparator circuit (54) outputs the signal STI and the tracking signal ST2 with this delayed phase.
Each time a level difference is detected. This comparison circuit (5
The output of 4) is supplied to a sampling hold circuit (55). On the other hand, this sampling hold circuit (55)
1 ton distance from the end of the track (14B) is 3
At some point within the period corresponding to d to 4d, ゛ζ
A sampling pulse SP2 is supplied. This pulse S
At time P2, as described above, the output of the operational amplifier (54) is the difference between the signal S'h and the signal ST2, so the output of this difference is sampled and held by the sampling and holding circuit (55). This sampling bold output is essentially a trunking control signal for the head (14B), and is supplied to, for example, a capsun motor (not shown) through an amplifier (56). and,
As a result, the amount of tape transport is controlled, and the level difference between signals ST1 and ST2 is zero, that is, when the head (IIB) scans the track (1, 4B>), the two trunks (14A) on both sides are In other words, it is controlled so that the center position of the gap of the head (IIB) in the width direction coincides with the center position of the trunk (14B).

The above describes tracking control in area Ah when the head (11B) scans the trunk (14B).
When IIB) scans, an I-ranking control signal is obtained in the same manner in the central area AT3.

On the other hand, when the head (IIA) scans the trunk (14A), the crosstalk of the pilot signals of the tracks (14B) on both sides is obtained in the area AT2 at the end of the trunk.
118) is obtained.

Considering the above, the sampling hold circuit (53
) and (55) are supplied with pulse SPA from the selection circuit (57).
and SPD are supplied. From the timing signal generation circuit (28), sampling pulses SP1 .
SP2, . . . SPs are supplied to the selection circuit (57). The selection circuit (57) is also supplied with a head switching signal and a mode switching signal from a terminal (58).

As shown in FIGS. 12A and 12B, in the normal reproduction mode, during the contact period of the head (11A) during period tA, pulses are generated as sampling pulses SPA and SPD of the sampling hold circuit (53) and (55>). SPs and SPo are selected, and a tracking control signal is obtained at region T2.Furthermore, during the contact period of the head (IIB) during period tB, pulses SP1, SP3, SP2, and SP4 are selected as sampling pulses SPA and SPo. A tracking control signal is obtained in the area AT1 and the front area AT2.

Next, in the double speed playback mode, the heads (118) and (IIB) forcefully scan the two trunks (IIA) and (IIB) as shown in FIG. 7, for example, by the solid line (8). In this case, the pilot signal output level of T1 to the trunk (14A) area and the pilot signal output level of the trunk (14B') area ΔT2 may be compared. therefore,
After this double speed mode, the sampling pulses SPA and SP are activated as shown in FIG. 12C.

For example, in period LA, pulses SP2 and SP
s is selected, and trunking is controlled based on the difference between the pilot signal outputs of the area ATL and the area AT2.

Also, when in triple speed mode, the adjacent trunk (14
A) (14B) have different azimuth angles, and "ζ" is also a rotating head (IIA) (
Since the IIB) scans alternately, the head does not scan trunks with different azimuths as in the case of double speed. In this example, the central area AT3 is used to control the rotary head so that it draws a scanning locus as shown by the solid line (9) in FIG. In this example, the rotary head scans the central position of the trunk (14B) in the central area AT3 only during the period tB;
Therefore, pulses SP3 and SP4 are selected as sampling pulses SPA and SPo. - In this way, according to the recording trunk pattern shown in Fig. 7, it is possible to set °ζ to the optimal tracking position not only during normal playback but also during double-speed playback and triple-speed playback. .

Note that the recording portions of the pilot signals in each area A'h and AT3 may have a period in which they partially overlap each other when viewed from a direction perpendicular to the longitudinal direction of the track, as shown in FIG. . In this case, as shown in the figure, the pilot signal is a signal P1 having a frequency f1 and a signal P2 having a different frequency f3, which are alternately recorded.

In this example, a bandpass filter, a detection circuit, and a sampling hold circuit for pilot signal detection are provided in two systems, one for signal P1 and one for signal P2, as shown in FIGS. 14A and B.
As shown in FIG. 1, during a period in which the pilot signals P1 and P2 are obtained in a mutually overlapping manner, the detection outputs of these signals P1 and P2 are sampled in each sampling and hold circuit by a sampling pulse SP. In this way, the tracking signal S of leading phase and lagging phase
Since T1 and Sr1 (FIG. 14C and D) are obtained, these signals S1'1 and Sr1 can be compared and the tracking control should be shifted so that the comparison output -C1 becomes zero.

Note that in the above example, the timing signal generation circuit (28
), the pulse PC from the pulse generator (17) is supplied to the pulse generator (17) using the rotational phase of the rotating head (118) (IIB) as a signal. 17), for example, prior to recording or playback, a predetermined signal is recorded on the rotary head (118) or (ilB) while the tape is stopped, and this is then played back. (Go to 11) or (IIB)
It is also possible to detect the beginning of the tape contact and use that detection signal.

Furthermore, although the above example is for a case where there are two rotating heads, in this invention, the tracks on which pilot signals are recorded and the track portions where pilot signals are not recorded may be alternated for each trunk. The number may be two or more.

Further, in the area AT3, the pilot signal may be recorded on the side of the force 11Ap).

Furthermore, the above example uses a rotating head device to record data by wrapping 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 rotating head device is used, which is a special type for reproduction, and which winds the tape at head angle intervals and head angle ranges, such as when energized.

Effects of the Invention As described above, in this invention, the pilot signal for tracking control is recorded in the same track as the PCM signal to be recorded, but in a different area.
This pilot signal can be easily detected during playback. Furthermore, since the pilot signal frequency can be arbitrarily selected, when new recorded information is recorded over the previously recorded information at a later point in time, it is easy to erase the previously recorded biloft signal.

Also, unlike the conventional example explained in FIGS. 1 and 2, which requires four different frequencies of the pilot signal, in the case of the present invention, the frequency of the pilot signal includes the cancellation signal. There may be two or three types of
This has the advantage that the configuration of the recording system and reproduction system is simplified.

Further, in the present invention, the first and second tracking signal recording areas ATL and Ar1 are provided at positions equidistant from the center position in the longitudinal direction of the trunk, and the pilot signal for trunking is recorded every other track. Since the trunks in which the viroft signals are recorded are different in areas AT1 and Ar1, tracking control can be performed so that the two tracks are scanned for the same amount of time during double-speed playback. As mentioned above, even when recording and reproducing using 2 + 161 rotary heads with different azimuth angles, one track is never lost.
- In the case of the ranking method, when the data of approximately +1 trunk is missing, as mentioned above, when recording the energized PCM signal, in order to eliminate the influence of burst errors as much as possible, it is necessary to Since interleaving processing is performed to disperse data, half of temporally continuous data is not missing. Therefore, inter-axis processing of this missing signal is easy, and a good signal can be obtained after interpolation.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing a recording trunk pattern as an example of a conventional tracking control method, Fig. 2 is a diagram for explaining the scanning locus of the rotary head during double-speed playback, and Fig. 3 is a reproduction output based on the fixed-point locus. FIG. 4 is a diagram showing an outline of the recording track pattern of the present invention, and FIG.
The figure is a diagram to explain the tracking control.
6 to 12 are diagrams for explaining recording and reproducing according to one example of the present invention, and FIGS. 13 and 14 are diagrams for explaining recording and reproducing according to other examples of the present invention. (118) (IIB) is a rotary head, (12) is a tape, (22) is a to/D converter, (31) is a pilot signal oscillator, (32) is an eraser signal generator, (45) is a D/8 register, and (54) is a comparator for obtaining a tracking error signal.
to S1. 8S2 is a recording area for the PCM own number, and 81'1°AT2 is a first and second recording area for tracking signals. Figure 1 Figure 6 Figure 2 Procedural Amendment June 9, 1982 1, Case Indication 1988 Patent Application No. 77148 2- Invention (') Name Recording method of PCM signal 3,
Relationship with the case of the person making the amendment Patent applicant address No. 6-7-35, Kitashinyo, Tokyo Parts Store Name (21
8) Norio Ohga, Representative Director of Sony Corporation

Claims (1)

[Claims] In a method in which a signal to be recorded is converted into PCM, the PCM signal is time-compressed, and a diagonal track is formed and recorded on a recording medium using a rotary head of 1M or more without forming a card band, each of the above-mentioned trunks is The first and second areas located equidistant from the center position in the longitudinal direction are used as tracking areas independent of the PCM signal recording area, and in the first and second tracking areas, A PCM signal recording method in which a trasokink pilot signal is recorded every other trunk, and the tracks on which the pilot signal is recorded are different between the first and second tracking areas.