JPS60191471A - Double speed reproducing method of pcm signal - Google Patents

Abstract

PURPOSE:To reproduce a PCM signal at a double speed and easily identify recording contents by obtaining the playback output of the PCM data at the same clock pitch with that during normal reproduction while a section wherein a signal which continues with time corresponds to a one-unit time with respect to an original analog signal. CONSTITUTION:The scanning track of the breadthwise center position of the gap of a rotary head crosses a straight line which connects breadthwise centers of respective tracks at lengthwise center positions. Tracks scanned by two rotary heads 1A and 1B are alternate tracks 4A1, 4B2, 4A4, 4B5..., so a couple of outputs of the heads 1A and 1B obtained in one turn are a half as much as original audio data obtained in a four-unit time, but data for a two-unit time are thinned out between alternate couples of data. The outputs of the heads 1A and 1B are written in RAMs 40 and 41 with signals RSWP and WC and corrected. Therefore, data D'1, D'4, D'7... for a unit time approximate to the original data are obtained at every two unit time at the clock pitch with that in normal reproduction, thus realizing triple-speed reproduction.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a double-speed reproduction method of a PCM signal such as a PCM audio signal recorded as diagonal tracks on a recording medium by a rotary head.

BACKGROUND TECHNOLOGY AND PROBLEMS When recording and reproducing information signals, such as audio signals,
By converting this audio signal into PCM, high-quality recording and playback can be achieved.

There are fixed head methods and rotating head methods for converting information signals into PCM and recording and reproducing them on magnetic tape.
The rotating head method is advantageous in that the relative speed of the head to the tape is fast and the recording density can be easily increased.

In this rotary head system, except for special applications such as those for broadcasting stations, a plurality of rotary heads, for example two, are usually used, and these rotary heads are mounted at an angular interval of approximately 360"/2=180", and the magnetic tape is are wound around the guide drum in the same angular range (180'), and two rotating heads alternately form one track each to record signals.

When recording PCM audio data using this rotary head method, generally speaking, a phase-separated light signal (hereinafter referred to as one segment) recorded as one track by one diagonal scan of the rotary head on the tape is used. The analog audio signal is divided into units of time, and processing is performed to complete interleaving and correction codes within this unit time, resulting in PCM data, and each unit of PCM data is processed as one track. Make sure to record it. In other words, it was an interleave with a complete segment.

However, when the data is completed in units of one segment, it has the advantage of making editing during playback and so-called variable speed playback easier, but on the other hand, playback from one rotating head may not be performed properly. The disadvantage is that the signal cannot be reproduced satisfactorily.

In other words, one of the rotating heads of the 21M may become clogged, resulting in a fairly long burst error, or
If the track widths of the two rotary heads are uneven due to variations in the characteristics of the two rotary heads or the heights of the two rotary heads in the direction of the rotation axis are different, the reproduced signal will be based on one of the two rotary heads. The signal from the track may not be reproduced at all, or the error correction capacity may be exceeded and errors may not be corrected.

Even in this case, in the so-called error correction circuit,
For example, it is possible to perform correction using error correction methods such as so-called pre-bold, which interpolates using the previous one track's worth of data, but this results in interpolating all of the data for one segment I. Therefore, there is a drawback that signal deterioration is inevitable.

If the information signal is a video signal, if the signal of one field is recorded as one track, there is a strong correlation between images between adjacent fields, so even if interpolation is performed as described above, signal deterioration will not be noticeable. However, if the information signal is an uncorrelated signal such as an audio signal, the signal deterioration becomes relatively noticeable when interpolation is performed as described above.

Therefore, when playing back a PCM signal recorded with interleaving complete with multiple segments, even if one segment is lost due to head clogging, etc., when viewed as a unit time signal of the original audio signal, The applicant previously proposed a new recording/reproducing device that prevents the signal for that unit time from being lost at all.

As an example of this new recording and reproducing apparatus, a two-segment complete interleave type apparatus that records and reproduces audio signals in PCM format will be explained.

FIG. 1 shows an example of a rotary head device in this case, and this is a case where there are two rotary magnetic heads.

The two rotating heads (l^) and (IB) are arranged with an angular spacing of 180°. On the other hand, magnetic tape (2)
along the circumference of the tape guide drum (3), its 180
It is wound over an angular range section smaller than the angular range, for example 90°. Then, the rotating heads (1^) and (IB) are rotated at, for example, 200 rpm in the direction shown by the arrow (5+1), and the tape (2) is transferred at a predetermined speed in the direction shown by the arrow (5T), so that the rotating head (IA)
and (IB), one diagonal magnetic track (48) and (48) are formed on the magnetic tape (2) as shown in FIG.
B) is formed and the signal is recorded.

In this case, PCM audio data for a time length of 1/2 rotation is recorded on one magnetic track.

In other words, the data is recorded while being compressed to 1/2 in terms of time.

In addition, in order to increase the recording density, the head (18) and (
The width directions of the gaps IB) are set in different directions with respect to the direction orthogonal to the scanning direction. In other words, the so-called azimuth angles are made different.

According to the above rotary head device, two rotary heads (I
There is a period in which A) and (IB) are not in contact with the magnetic tape (this is a period corresponding to an angular range of 90° in this example), and this period is used to perform redundancy such as parity for PCM data. By processing data addition, it is possible to reduce the amount of buffer memory in the recording device.

Next, an embodiment of a recording device and a reproducing device thereof according to the present invention using this rotary head device will be described.

FIG. 3 shows an example of the recording system in which an audio signal is recorded as a two-channel signal, a right channel and a left channel.

That is, in FIG. 3, the left channel audio signal SL is input to the switch circuit (13) through the input terminal (11).
), and the right channel audio signal sR is supplied to the other input terminal of the switch circuit (13) through the input terminal (12). This switch circuit (13) is a control signal generating circuit (14)
are alternately switched by a switching signal SW from the A/D converter (15).

The control signal generation circuit (14) is based on the master clock signal from the master clock generation circuit Om.
In addition to this signal SW, various control signals such as t&description are generated.

The switching signal SW of the switch circuit (13) has the same frequency as the sampling frequency in the A/D converter, for example, 48
kHz, and this is a rectangular wave signal with a duty factor of 50% as shown in Figure 4A.For example, as shown in Figure 4A, when this signal SW is at a high level, the left channel audio signal is selected. However, when this signal SW is at a low level, the switch circuit (13) is switched to select the right channel audio signal.

In the A/D converter (15), each left or right channel is sampled at a sampling frequency of 481)Iz. The signal SP from the control signal generation circuit (14) is this sampling signal, and the left channel and right channel audio signals are each sampled by this signal SP, and this sampled data is, for example, 16 times per sample.
It is converted into a bit PCM signal So. FIG. 4B shows the output signal So of this A/D converter, LO, Li+
L2...indicates l samples of the audio PCM signal of the left channel, and RO, R1, R2
. . . each indicates one sample of the audio PCM signal of the right channel.

The output signal So of the A/D converter (15) is supplied via a switch circuit (16) to the input ends of RAMs (17) and (18) for redundant data addition and interleaving processing. The switch circuit (16) is switched every rotation by a signal R3W (FIG. 4F) synchronized with the rotation of the heads (1^) and (IB) from the control signal generating circuit (14).

Here, phase servo is applied to the rotating heads (IA) (IB) in the following manner.

That is, a signal S8 with a period equal to the rotation period of the head is obtained from the control signal generation circuit (14), and this is supplied to the phase comparator circuit (19).
This phase comparison circuit (
19), the phases of the two are compared, and the comparison error output is supplied to the motor (21) that rotationally drives the heads (LA) and (IB).
) is controlled to rotate in phase synchronization with the signal Sg. Since the signal R3W has a constant phase relationship with this signal Ss, this signal R3W has a constant phase relationship with this signal Ss.
The phases of 3W are synchronized.

In this case, when the rising and falling points of signal R3W are taken as phase 0°, the head (IA) scans over the tape (2) during the period HA from 90° to 180°, and from 270° to
The servo is applied so that the head (IB) scans the tape (2) during the period HB of 360° (=0'').

The switch circuit (16) is switched between one output terminal and the other output terminal by the signal R3W, but during the period TB for one rotation when the signal R3W is at a low level, the signal So is switched to one output terminal and the other output terminal.
During the period TA when (II-R3W is at high level), the signal So is supplied to the data input terminal of RAM (1B).
) is supplied to the data input terminal of the

On the other hand, from the control signal generation circuit (14), the RAM
Write control signals RW and read control signals RR of (17) and (18) are obtained, and these signals RW and RR are sent to the RAM (1) through switch circuits (22) and (23).
7) and (18) are selectively supplied to the control terminals. The switch circuits (22) and (23) are also switched by the signal R3W, and like the switch circuit (16), they are switched to the state shown in the diagram during the period TA, and to the opposite state from the state shown in the diagram during the period TB. . Therefore, during the period TB, the signal So is
(1B), the signal So is written for one rotation period by the write control signal RW, and in the period TA, the signal So is written for the same period to the RAM (17>) by the write control signal RW.

In this way, the audio signal data of the right channel and the left channel of the bone are alternately written into the RAMs (17) and (18) during one rotation.

Here, the output signal SO of the A/D converter (15) is divided into unit time lengths equivalent to one track, and this is divided into signal DI.
, D2... (FIG. 4C), every two unit time signals, that is, the signal Dz.

D2, D5, Ds... are stored in the RAM (17), and signals D3, D4, Dt, De... are stored in the RAM (17).
8). Here, the unit time signals Di, D2
The number of samples included in each of . . . is 1440. That is, as shown in Fig. 4B, there are 720 samples of the left channel audio signal up to sample ■, o = Ltas, and 720 samples of the right channel audio signal up to sample Ro = R15s, for a total of 1440 samples. .

P written in RAM (17) and (18) in this way
The CM data is stored in the 90-degree area before HA and HB during the period when the head (18) and (IB) are in strong contact with the tape (2).
Parity is generated and added in periods PA and PB of ° minutes, and in periods HA and HB, respectively, PCM data with parity added to the head (LA) and (IB
) is recorded on tape (2).

In this case, the rotating head (1Δ)(I
B) Two tracks (4^) formed by (4B
) have two unit time signals CD1. D2).

(D3, D4), [D5, De)..., the even-numbered data and odd-numbered data are the even-numbered data of one unit time signal, as shown in Figure 2. and the even number 1 H data of the other unit time signal are placed on one track (4A) of the 1st controller.
Further, the odd numbered data of one unit time signal and the odd numbered data of the other unit time signal are respectively recorded on the same trunk (4B), and this The correction code is completed within a signal recorded on each track, that is, one segment of data.

In other words, the interleave completes two segments, and the correction code completes one segment.

That is, the output signals of the RAMs (17) and (18) are sent to the parity generation addition circuit (2) through the switch circuit (24).
5) is selectively supplied. The output signal of the parity generation/addition circuit (25) is returned to the input terminals of the RAMs (17) and (18) via the switch circuit (26).

Switch turns II (24) and (26) also receive the signal R3W.
By switch circuit (16).

It is switched in synchronization with (22) and (23). Then, the control signal generation circuit (14) supplies the parity generation/addition circuit (25) with a control signal CP that is at a high level during periods PA and PB, as shown in FIG. 4G, and this signal CP is at a high level. During this period, an error correction code is generated and added to the manually-powered PCM data. In other words, in the period TA, 1. When the written data reaches the period TB, switch time II (23)
Since (24) and (26) are in the opposite state to the state shown in the figure, the data is transferred from the RAM (17) to the switch circuit (
24) to the parity generation addition circuit (25). In this circuit (25), the period PA
Since the signal CP is at a high level at PB and PB, an error correction code is generated and added to the input data during this period, and the added data is sent to the switch circuit (26).
The data is then written to the RAM (17) again via the . In this case, for example, even-numbered data (IE) of the signal D1 and even-numbered data (2E) of the signal D2 are read out from the RAM (17) during the period PA, and the encoder (2E) is read out from the RAM (17).
5), and an error correction code is generated and added to one segment of data consisting of this data (IE) and (2E).4 In period PB, the odd-numbered data (10) of signal D1 and the signal An error correction code is generated and added to one segment of data consisting of the odd-numbered data (20) of D2.

FIG.
20) and the code structure of redundant data such as error correction code.

In the figure, one column in the vertical direction is one block, and 0 to
128 blocks with 127 block addresses are arranged horizontally.

Error correction encoding is performed using 8 bits as one symbol, so the sample data consists of the upper 8 bits and lower 8 bits.
The bits are shown with suffixes A and B respectively.

A first error correction code C1 is applied in the vertical direction of this two-dimensional array, and a second error correction code C2 is applied in the horizontal direction. The error correction code C1 is (32
, 30) on CF(28), and the code sequence is interleaved to complete two blocks.

For example, 32 symbols (LO
A, l-081L2A, 1,2B, “◆Meeting” L 29
0AIL 2901+1 L 292AI L 292
B+ ” ” L 680^, L 611OB+P
20+P 21) to 1 of the error correction code C1
A code sequence is formed. In addition, 32 symbols (Ro^, Rosl'・1φ・Keyaki R2soA,
R29OB.

""...R6BOA, R680B, P Io, P
t't), one code sequence of the error correction code C1 is formed. The 4 (fixed parity symbol P1o+Pt't+P2O1P21 obtained at this time is the intra-block address 29 of the odd-numbered block of the block address)
~32.

Furthermore, the 128 blocks are divided into 32 blocks every four blocks, and the code sequence of the second error correction code C2 is formed by the 32 symbols extracted from each of the four blocks. This error correction code 5C2 is a Reed-Solomon code on GF (2E') of (32, 24), and the block address is (0 to 127).
) of 128 (1 & l blocks every 4 blocks (for example, 0, 4, 8. 120. 12
One code sequence of the error correction code C2 is formed by 32 symbols located at the same intra-block address of block address 4).

In other words, 4 blocks are interleaved for the error correction code C2, and the block address is (48
The parity symbol of the error correction code C2 is located in the 32nd block from 79).

Thus, the error correction code CI in period PA.

The data (IE) and (2E) added when C2 is generated are read out at HA during the period when the head (IA) is in contact with the tape (2) immediately after that, and this is sent to the head (LA) through the recording processor (27). As shown in Figure 3, data (IE) is stored in the first half of the track (4A).
), and data (2E) is recorded in the latter half.

Similarly, the data (10) and (20) added to the error correction code Ct and C2 in the period PB are read out in the period HB when the head (IB) is in contact with the tape (2) immediately after that. It is supplied to the head (IB) through the recording processor (27), and is recorded on the track (4) as shown in FIG.
As B), data (20) is now recorded in the first half, and data (10) is recorded in the second half.

Note that the parity symbols for 32 blocks are track (
4A) The area drawn by crossing the diagonal lines in the center of (4B) (
6) will be recorded.

The same goes for the RAM (1B), and the data stored in this RAM (1B) in the period TB is stored in the parity generation addition circuit (25) in the periods PA and PB of the next period TA.
), an error correction code is generated, added to the data, and returned to a predetermined address in the RAM (1B) for storage. Then, in the periods HA and HB of the period TA, the heads (IA) and (IB) track (4^) and (4B) the even-numbered data (3E) and (4E) and the odd-numbered data of the data D3 and D4. Data (30)
and 8 (40) are tracked (4A) (4B) in the same manner as above.
) are allocated and recorded in the first half and second half of (Figure 4H)
reference).

In this case, data is time-compressed to 1/2 in the process of writing to and reading from RAMs (17) and (18).

In the recording processor (27), a block synchronization signal, segment address data, block address data, etc. are added to one block of data, and a signal that makes the PCM data suitable for recording and reproduction is added.
For example, processing is also performed to modulate the signal so that the DC component is as small as possible. FIG. 4I shows the structure of one block of data.

The operations of the above RAMs (17) and (18) are shown in the fourth diagram and E, respectively.

Next, P
Let us explain the reproduction of CM audio signals.

Figure 6 shows an example of this regeneration system. Further, FIGS. 7A to 7G are time charts for use in explaining the reproduction system.

During this playback, as well as during recording, the
) and (IB) are controlled to rotate in synchronization with a signal Ssp of one rotation period from the control signal generation circuit (30). In other words, 1 (
The output signal PG from the pulse generator (20) that generates the pulse llIl is supplied to the phase comparison circuit (32), and the phase of this signal and the signal Ssp from the control signal generation circuit (30) are compared. The phase of the motor (21) is controlled by the output. In this case, the switching signal R of RAM (40) and (41) is used for data processing during reproduction.
3Wp (FIG. 7C) (which is obtained from the control signal generation circuit (30)) is at a high level during one rotation period TC and during one rotation period TD during which it is at a low level. The angle of rotation of the tape is (18) and (IB) during the rotation angle periods HC and HD, respectively.

(2). '9 That is, a reproduced signal is obtained from the head (IA) during the period HC as shown in FIG. 7A, and a reproduced signal is obtained from the head (IB) during the period HD as shown in FIG. 7B. The reproduction head outputs thus obtained are supplied to one and the other input ends of the switch circuit (34) through amplifiers (33^) and (33B), respectively. This switch circuit (34) is switched by the head switching signal SH, and during its high level period, it is in the state shown in the figure, that is, the state in which the output signal of the amplifier (33A) is selected, and during its low level period, the output signal of the amplifier (33B) is selected. The state is alternately switched to select the output. At the rising and falling points, which are the switching points of the head output switching signal SH, the heads (18) and (IB) are connected to the tape (2).
Any time may be used as long as the time period does not include contact with either person.

In this way, a signal is obtained from the switch circuit (34) in which the outputs of the head (1^) and (IB) are alternately and consecutively arranged, and this signal is supplied to the digital signal restoration circuit (35) to restore rOJ and rlJ. Returned to digital signal 10, RAM write control signal generation circuit (36)
supplied to

In this circuit (36), a write address and a write timing signal RWp for the two RAMs (40) and (41) are generated based on address data for each block.

The switch circuit @ (3B) is for switching between the write period and the error correction period of the RAM (40) (41).This is because the control signal generation circuit (30) is at high level during the period HC and HD, and the period 9 after HC
Signal WC that becomes low level during period PC for 0° rotation angle and period PD for 90° rotation angle after period HD (Fig. 7D
) can be switched. In other words, the switch circuit (3
8) is switched to the circuit (36) side during the high level periods HC and HD of the signal WC, and to the output end side of the error correction circuit (37) during the low level periods PC and PD.

The output of this switch circuit (38) is selectively input to the RAMs (40) and (41) via a switch circuit (39).

2 On the other hand, the write address and write timing signal RWp from the circuit (36) are sent to these RAM (40) and (
41) via a switch circuit (42). Also, from the control signal generation circuit (30)
A read control signal RRp of M(40) and (41) is obtained, and this read control signal RRp is connected to the switch circuit (4
3) is selectively supplied to RAMs (40) and (41). The output signals of the RAMs (40) and (41) are selectively transferred to the correction circuit (44) by the switch circuit (44).
37), and is also supplied to the input terminal of the switch circuit (
45) is selectively supplied to the modification circuit (46). And these switch circuits (39) (42) (4
3) (44) and (45) are the aforementioned switching signal R3Wp
can be switched by

That is, in this case, the switch circuits (39) (42)
(43) (44) (45) The signal R3Wp is in the state shown in the figure during the period TC when it is at a high level.
During the period TD when Wp is at a low level, the state is switched to the state opposite to that shown in the figure.

Therefore, the output signal of the head (18) is written to a predetermined address of the RAM (40) during the periods HC and HD of the period TO using the write address and write timing signal from the circuit (36). and,
During periods PC and PD after periods HC and HD, respectively, the signal WC causes the first switch (38) to write the output of the correction circuit (37) into the RAM (40). At this time, the output of the RAM (40) is the correction circuit (37).
), the switch circuit (44) is in a state where the data is supplied to the RAM (40), the error is detected and corrected using parity C1+C2 in the correction circuit (37), and the corrected data is written to the RAM (40) again. It becomes like this.

Similarly, in the RAM (41), data is written in periods HC and HD of period TD, and data is written in periods PC and P.
At step D, the data is corrected and the corrected data is written to the RAM (41) again.

In this way, the reproduced data written in the RAM (40) (41) with the third correction is transferred to the control signal generation circuit (
30), the data is expanded twice and read out. That is, the switch circuit (43) is switched to the RAM (41) side during the period TC and to the R'AM (40) side during the period TD by the signal R3Wp, so that the RAM which is not in the write state is placed in the read state. , and from RAM (41) in period TC,
Data is read from the RAM (40) during period TD.

Note that during recording, the sample data that was dispersed within one segment due to interleaving processing is read out from RAM (40) and (41) during playback by controlling the address. The array sample data has been returned.

Moreover, the samples of the left channel and the samples of the right channel are alternately continuous.

The read data is selectively switched by a switch circuit (45) to form a continuous signal as shown in FIG. The data is error corrected in this correction circuit (46). For this modification, for example, average value interpolation or pre-hold techniques are used.

The output of this correction circuit (46) is data of the left and right channels appearing alternately for each sample, and this is the output of the D/
It is returned to an analog signal in the A converter (47). The signal returned to this analog signal is sent to the switch circuit (4
8), this switch circuit (4B) is alternately switched to one and the other output terminal by a switching signal SWp similar to the switching signal SW during recording, and the amplifier (49^)
and (49B) respectively to output terminals (50A) and (50B), respectively.
This is obtained by reproducing the L' and right channel audio signals SJ.

Time charts of the operating states of the RAMs (40) and (41) during the above reproduction are shown in FIGS. 7E and 7F.

As described above, the audio signals for the two left and right channels are converted into PCM and recorded and reproduced using the interleave method that completes two segments and the correction code method that completes the segment.

By the way, in the above-mentioned recording/reproducing apparatus, there is a demand for double-speed reproduction such as double-speed reproduction or triple-speed reproduction in order to perform a fluency search or find the beginning of a song. In the case of the rotary head system, during this double speed reproduction, the rotary head scans every other track, every second trunk, and so on, and at N times speed, the rotary head scans every N-1 track.

In this case, if the PCM signal is recorded in a one-segment complete format with interleaving and correction codes, one segment of data can be obtained even if only one track information is obtained every N-1 during N-times speed playback. If obtained, Part 1
A segment's worth of signals can be completely regenerated.

However, if the PCM signal is recorded with interleaving completed in a plurality of segments as described above, only one segment's worth of data can be read out of the plurality of segments in which the data is completed during double-speed playback. In the above example, the time length for l segment is:
Each time, only 1/2 of the data is obtained. Therefore, the conventional double-speed reproduction method of a PCM signal recorded in a one-segment complete format cannot be applied as is.

However, in the case of this interleaving method that completes multiple segments, data for the time length of one segment can only be obtained by, for example, 1/2, but data for the time length of two segments can be obtained, so this can be used. This enables double-speed playback with high performance.

OBJECTS OF THE INVENTION The present invention provides a good double-speed reproduction method for a PCM signal recorded by a rotary head with interleaving completed in a plurality of segments.

Summary of the Invention This invention is a rotating head type recording and reproducing system, and a PC in which interleaving is recorded in a state in which multiple segments are completed.
When reproducing the M signal at a speed N times the normal reproduction speed, the period in which the signal is continuous in time when viewed from the original analog signal is set to one unit time, and the PCM data is This is a double-speed reproduction method of the PCM signal in which the reproduced output is obtained at the same clock pitch as during normal reproduction.

Embodiment As an embodiment of the method of the present invention, FIG. I will explain while referring to it.

In this example, the scanning locus of the center position in the width direction of the gear of the rotary head is the head (1^) in FIG. 8A.
) is made to intersect the straight line connecting the widthwise center of each track at the longitudinal center position of the track, as shown by the solid line arrow, and that of the head (IB) as shown by the broken line arrow. .

In other words, each of the rotating heads (IA) (IB) scans only one track (hereinafter referred to as on-track). As a technique for tracking in this way, for example, a technique for controlling the tracking position using a control signal recorded and reproduced by a fixed head at one end in the width direction of the tape and a signal indicating the rotational phase of a rotary head is used. Can be used.

In this on-track 3x speed playback, as is clear from Figure 8A, 2111! Rotating head (1^) (IB)
Each of them can be made to scan just the corresponding azimuth track.

However, in this 3x speed playback, two rotating heads (IA
) (IB)] - Racks are scanned every second track (48r) (4B2) (4^4) (4B5)
..., so the outputs of heads (18) and (IB) are head (1^) (I) as shown in Figure 8B and C.
One set of data obtained in one rotation of B) is half of the original audio data for 4 units of time, but the distance between each set of data is 21! The data for about 1 hour has been thinned out.

The outputs of the rotary disks (1^) and (IB) are processed in the reproduction system shown in Fig. 6, but in this example, reading from the RAMs (40) and (41) is Different from normal playback.

That is, the outputs of heads (IA) and (IB) are
As shown in FIGS. DG, the data is written and corrected in the RAMs (40) and (41) by the signal R3Wp and the signal WC, respectively.

The thus corrected data is read out from the RAM (40) in a period TB and from the RAM (41) in a period TA, but in this example, each track (4A) (4B
) The odd-numbered data or even-numbered data recorded in the latter half of the data is not read out, and instead of that data, for example, data indicating a specific value is obtained as a readout output, and an error flag is set for each sample data.

When these readout outputs are supplied to the W+V rectifying circuit (46), the even and odd data (IB) (40) (7B) are read as correct data.
(100) (13E) (160) ..., the interpolated values (10') (4E
')(To')(IOE')... are formed. Therefore, as shown in FIG. 8G, the error correction circuit (46) outputs data Dr for a unit time that approximates the original data.
', Dj + D7'... are obtained. In this case, data 07. D. . . is obtained at the same clock pitch as during normal reproduction, but is obtained every two time units, realizing triple-speed reproduction.

In this case, since the reproduced output data is obtained with the same clock pinch as during normal reproduction, it has the advantage that it is difficult to hear as an audio output.

In addition, in the above example, the recording positions of even-numbered data and odd-numbered data of the temporally later one segment of data written to RAM (17) and (18) are reversed. You can also do this. For example, data (2E) is placed in the first half of track (4B), and data (20) is placed in the first half of track (4B).
are recorded in the latter half of track (4A).

In addition, not only when recording audio signals in PCM,
Needless to say, method 1 can be used when recording other analog signals using PCM.

Furthermore, over two or more N segments,
It is also possible to allocate even-numbered data and odd-numbered data of each one segment of data for N segments to separate segments (tracks). That is, the PCM signal may be recorded in a state where N (N is an integer of 2 or more) interleaved segments are completed. However, even in this case, as long as the correction code is completed in one segment as described above, there is an effect that the reproduced signal can be reproduced satisfactorily.

Effects of the Invention According to the present invention, double-speed playback of a PCM signal recorded using an interleaved method with multiple segments completed is possible, and since playback data is obtained with the same clock pinch as during normal playback, the recorded content can be reproduced at double speed. This has the advantage of easy identification.

[Brief explanation of the drawing]

FIG. 1 is a diagram for explaining an example of a rotary head device used in the present invention, FIG. 2 is a diagram showing its recording track pattern, FIG. 3 is a system diagram of an example of its recording system, and FIG. 5 and 5 are diagrams showing a time chart for explaining this, FIG. 6 is a system diagram of an example of the reproduction system, FIG. 7 is a diagram showing a time chart for explaining this, and FIG. 8 is a diagram showing a time chart for explaining this. FIG. 2 is a diagram for explaining an example of an invention method. (IA) and (IB) are rotating heads, (2) is a tape,
(3) is a guide drum, (IT) (1B> (40) and (41) are RAM, and (30) is a control signal generation circuit. 4

Claims (1)

[Claims] When the signal recorded by one diagonal scan of the rotary head on the recording medium is defined as one segment, the PCM signal of the analog signal divided into units of time corresponding to one segment is a signal of a different unit time. The above-mentioned P is recorded from a recording medium in which interleaving is recorded in a state in which multiple segments are completed so that the above-mentioned one segment is formed by
When reproducing a CM signal at a speed N times that of normal reproduction, the interval force is set to q units of time, which is a temporally continuous signal when viewed from the original analog signal, and the PCM data is A double-speed playback method for PCM signals in which the playback output is obtained at the same clock pitch as during normal playback.