JPS6280872A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To reproduce a signal by a high definition device and a low definition device by sectioning a track of a magnetic tape into 4 fields, recording a digital signal while an analog signal is sampled by frequencies (f) and 2f to one of the fields in a prescribed relation. CONSTITUTION:An oblique track is formed by a rotary magnetic head in the lengthwise direction of a magnetic tape. One track having a winding angle of 221 deg. is sectioned into 4 fields A-D by 54 deg.. Stereo audio signals L, R are sampled by a frequency (f) and digitized to record an odd number L signal and an even number R signal in the field A and to record an odd number R signal and an even number L signal to the next rack field adjacent to the former track. The signals L, R are sampled by frequency 2f, a new odd number L odd number R signal and the even number L signal are recorded to a field A adjacent to the former field. Thus, the signal is reproduced by a high definition device and the low definition device.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic recording and reproducing apparatus for recording and reproducing information using a rotating magnetic head such as a video tape recorder.

[Summary of the invention]

The present invention is a magnetic recording/reproducing device in which a track formed by a rotating magnetic head at an angle with respect to the longitudinal direction of a magnetic tape is divided into a plurality of regions.

When an analog signal is sampled with a clock with a frequency of 2f and converted into a digital signal, the data sampled with the odd-numbered clock is recorded as one group in one area, and the data sampled with the even-numbered clock is recorded as one group. When the analog signal is sampled with a clock of frequency f and converted into a digital signal, the data sampled with the clock of frequency f is recorded as one group in the odd or even number of 0 frequency 2f. By recording the data sampled at the second clock in an area corresponding to the recording area, not only can you enjoy higher quality audio signals on devices that operate with a higher frequency clock, but also the recording This allows the signal to be reproduced even in devices that operate with a lower frequency clock.

[Conventional technology]

Recently, pH8mm video tape recorders have been standardized.
It has been commercialized. In this 81111 video tape recorder, the rotating diameter of the rotating magnetic head (the diameter of the rotating drum) is 40I, and the winding angle of the magnetic tape around the rotating drum is 221 degrees.

The part corresponding to the winding angle of 180 degrees receives the video signal, and the part corresponding to the winding angle of 36 degrees receives the P signal.
A CM audio signal is recorded (the remaining 5th part is considered as a surplus). If we divide this 36-degree area into more detail, we can see a part a where the clock signal is recorded, a part where data such as PCM audio signals are recorded, a margin part C for after-recording, and the video of the previous field. The video overlap section d is divided into a video overlap section d in which the signal is continuously recorded. And 2
For the entire part corresponding to the winding angle of 21 degrees.

Pilot signals for tracking f□, f2. f1, f
, are recorded sequentially for each track. These pilot signals f, f, , f, , f4 each have, for example, fN 158. f, 150. fH/36, f1
1/40 (f, 41 horizontal synchronization ff1) (7) (
Receives M number. From the crosstalk components from the left and right tracks of the pilot signal continuously recorded on each track,
A tracking error signal is generated. The rotation speed of the rotating magnetic head is determined by NTSC because it records video signals.
In the system, it is 1800 r.pm, and in the PAL system, it is 1500 ppm. Furthermore, a plurality (5) of parts corresponding to a winding angle of 36 degrees are formed in the part corresponding to a winding angle of 180 degrees, so that only audio signals can be recorded.

The audio signal recorded in the 36 degree area is.

Its sampling frequency is 2f (approximately 31.5kHz)
The number of quantization bits is 10 bits (however, 10 bit data is converted (compressed) to 8 bits and recorded on the magnetic tape in Table 1), and the number of channels is 2.

On the other hand, R-DAT has recently been standardized in order to record and reproduce audio signals on magnetic tape with even higher quality.

In R-DAT, the winding angle of the magnetic tape is 90 degrees, the diameter of the rotating drum is 30 degrees, and the sampling frequency is 4 degrees.
The frequency is 8 kHz, 44.1-7, or 32 kHz, the number of quantization bits is 16 bits, and the number of channels is 2.

The track corresponding to the winding angle of 90 degrees is divided into 16 parts as shown in FIG. 4, and data is recorded in each part as shown in Table 1. Here, one block consists of 288 bits of data, and 8 bits of data are converted (modulated) to 10 bits and recorded on the magnetic tape.

Note that fch is a clock signal with a frequency of 9.408M&.

As can be seen from Table 1, this data mainly consists of 1 part 2.3.
4, a tracking signal recording section consisting of sections 5.6 and 7, a PCM audio signal recording section consisting of section 8.9, and 1 section 10.11.12.
a tracking signal recording section consisting of parts 13, 14.
15 subcode signal recording sections.

[Problem that the invention seeks to solve]

There are two methods for recording and playing back digital audio signals on magnetic tape using a rotating magnetic head, but the 8m video tape recorder is originally designed to record video signals, so it is possible to record and play back digital audio signals on magnetic tape. The sampling frequency of the R-DAT was also low, and the sound quality was inferior to that of the R-DAT. On the other hand, R-DAT has the disadvantage that it can only record and reproduce audio signals and cannot record and reproduce video signals.

[Means for solving problems]

FIG. 1 shows a block diagram of a magnetic recording/reproducing apparatus (8 mm video tape recorder) according to the present invention.

In the figure, 1 is a rotating drum (4) spaced 180 degrees apart from each other.
(not shown), the rotary magnetic head 1 is alternately supplied with signals from the recording amplifier 4 via a switch 2.3, and the signal from the rotary magnetic head 1 is The signal is output to the regenerative amplifier 5 via the switch 2.3. The recording amplifier 4 is supplied with signals from a video modulator 8 and a PCM encoder 9 via a switch 6, and is also supplied with a pilot signal output from a pilot signal generator 35. Also, the signal S;- from the regenerative amplifier 5 is the switch 7.
The signal is output to a video demodulator 10 and a PCM decoder 11 via. 12 and 13 are a PCM decoder and a PCM encoder compatible with the format l<-DAT, and the signal from the regenerative amplifier 5 is converted into PCM through the switch 7.
The output of the PCM encoder 13 is supplied to the recording amplifier 4 via the switch 6. An oscillator 14 generates a clock signal f'ch and outputs it to the PCM encoder 13.

Reference numeral 15 denotes a motor that rotates the rotating drum, and includes a wave number generator 16 and a pulse generator 17.

It is driven by a drive circuit 18. Frequency generator 16
The output is input to the frequency control circuit 19 and compared with a predetermined reference signal output from the built-in oscillation circuit. Frequency control circuit 19 outputs the error signal. 20 is a phase control circuit, which controls the vertical synchronization signal included in the recorded video signal separated by the synchronization separation circuit 22, the reference signal output from the oscillator 23, the reference signal output from the PCM decoder 12, or the PCM encoder 13. One of the reference signals to be output is input as a reference signal via the switch 21. The phase control circuit 20 compares the phases of the pulses output by the pulse generator 17 and the reference signal, and outputs a signal corresponding to the error. The output of the frequency control circuit 19 and the output of the phase control circuit 20 are added by an adder circuit 24 and supplied to the drive circuit 18.

25 is a motor that rotates a capstan (not shown), and is equipped with a frequency generator 26.

The output of the frequency generator 26 is supplied to a frequency control circuit 27 and a frequency dividing circuit 28. The frequency control circuit 27 compares the output signal of the frequency generator 26 with a predetermined signal output from the built-in oscillation circuit, and adds the error signal to the addition circuit 30.
It is output to. The frequency dividing circuit 28 divides the frequency of the output of the frequency generator 26 and outputs the divided signal to the phase control circuit 29 . The phase control circuit 29 is: - The signal from the switch 21 and the frequency divider circuit 2
8 and the error signal is sent to switch 34.
It is output to the adder circuit 30 via. The adder circuit 30 adds the output of the frequency control circuit 27 and the output of the phase control circuit 29, and outputs the result to the drive circuit 31.

The drive circuit 31 is configured to drive the motor 25. 32 is a tracking control circuit that separates and extracts a pilot signal from the output of the regenerative amplifier 5, generates a tracking error signal, and sends the signal to the adder circuit 30 via a switch 34.
It is output to. 33 is a central processing unit (CPU) such as a microcomputer, which controls each circuit, means, switch, etc. in conjunction with a main central processing unit (not shown).

[Effect]

The effect will now be explained. When a command to record a normal video signal and an accompanying PCM audio signal is input, the CPU 33 controls the frequency control circuits 19.27.
A control signal is sent to the drive circuit 18.
rpm, 1500 ppm in the case of the PAL system), and the capstan is rotated by the motor 25 so that the speed of the magnetic tape (not shown) becomes the standard speed.

At this time, the frequency control circuit 19 applies servo so that the frequency of the signal output by the frequency generator 16 becomes equal to the frequency of the built-in reference signal. At this time, the switch 21 is switched to select the output of the synchronization separation circuit 22, and the rotary drum is rotated so as to be synchronized with the phase of the vertical synchronization signal in the video signal to be recorded. The phase control circuit 20 generates a head switching pulse (H5WP) that serves as a reference for switching between the two rotating magnetic heads, and outputs it to each circuit.

Similarly, frequency servo and phase servo are applied to the motor 25 by the frequency control circuit 27 and the phase control circuit 29. At this time, the phase control circuit 29 uses the output of the synchronous separation circuit 22 outputted by the switch 21 as a reference, and supplies an error signal between the output of the frequency dividing circuit 28 and the output to the addition circuit 30 via the switch 34. Therefore, the predetermined speed (14 in the case of NTSC system)
．． 345101117s, 20 for PAL system
．． The speed of the magnetic tape is controlled to be 05 lnm/s).

The video signal to be recorded is input to a video modulator 8 and frequency modulated. Also, the recorded audio signal is
These signals, which are input to the M encoder 9 and digitized (PCM), are sent to the recording amplifier 4 via the switch 6.
, further supplied to the rotary magnetic head 1 via the switch 2.3, and recorded on the magnetic tape. Phase control circuit 20
1 based on the head switching pulse output by
A video signal is recorded in the 80-degree video signal recording section, and an audio signal is recorded in the 36-degree audio signal recording section. Also, at this time, a tracking pilot signal generated by the pilot signal generator 35 is frequency-multiplexed with the video signal and the PCM audio signal and recorded. The frequency can be the same as the pilot signal in the case of the PAL system. In this way, the clock signal f'c
It becomes easy to frequency divide and generate a pilot signal from h.

When reproducing a video signal, the output signal of the oscillator 23 (signal corresponding to the vertical synchronization signal) is supplied to the phase control circuit 20 as a reference signal via the switch 21. Further, the switch 34 is switched to the tracking control circuit 32 side, and the phase servo of the motor 25 is performed in response to the tracking error signal generated from the crosstalk components of the pilot signals recorded on the left and right adjacent tracks.

The reproduction signal from the rotating magnetic head 1 is transmitted to the video demodulator 10 and P via the switch 2.3, the reproduction amplifier 5, and the switch 7.
The signal is input to the GM decoder 11. Therefore, the video signal recorded in the 180-degree video signal recording section and the audio signal recorded in the 36-degree audio signal recording section are each demodulated and output.

Table 2 When only high-quality audio signals are to be recorded, the audio signals are input to the PCM encoder 13 and digitized. The PCM encoder 13 is a so-called R-DAT.
The same PCM encoder as can be used. However, the PCM encoder 13 is controlled at a different timing by a different clock than in the R-DAT.

That is, in the present invention, one track having a length corresponding to a winding angle of 221 degrees has a length of 54 degrees as shown in FIG.
Divided into four areas of degree length.

On the left and right sides are 2.044 degrees and 2. A surplus of '956 degrees is provided. The 54-degree-long region A to A is further divided into nine parts as shown in FIG.

Data is recorded in each part as shown in Table 2.

As is clear from Table 2, in the present invention, the tracking data recording units 5, 6, 7 and 10 in Table 1
．． 11.12. Also, the format is such that the last margin section 16 is removed. Further, the clock f'ch here is, for example, 12.864M7 (=160.8
x288x (10/8)10.0045),
Of course, the combination can be changed within the range where the winding angle is 54 degrees and the recording time is 4500 μs.5For example, the 2-block PLL (PCM) clock recording section can be eliminated, and the margin section can be changed from 8.8 to 10.8. You can also change it to a block. Furthermore, the remaining portions at both ends can be arbitrarily selected.

In this way, R-DA, which has already been standardized,
Information can be recorded and reproduced simply by changing the timing without changing the coding of the T format.

The audio signal input to the PCM encoder 13 is
The signal is digitized in response to the clock signal f'ch inputted from the oscillator 14, and its timing is controlled by the CPU 33 to convert it into a signal in the format shown in Table 2. This signal is sent to the switch 6, the recording amplifier 4,
The signal is supplied to the rotating magnetic head 1 via switches 2 and 3, and recorded on the magnetic tape. At this time, the phase control circuit 2
Based on the head switching pulse outputted by o,
An area pulse corresponding to at least one of the areas A to A is generated, and a signal is recorded in the area corresponding to the area pulse.

At this time, the frequency control circuit 19. The WJ driving circuit 18 is controlled by the CPU 33 to rotate the rotary drum at 2000 rpm. Further, the switch 21 supplies a signal synchronized with the clock f'ch output from the PCM encoder 13 to the phase control circuit 20 as a reference signal. Furthermore, the frequency control circuit 27 and the drive circuit 31 are controlled in the same manner, and the speed of the magnetic tape is set to the standard speed of PAL system, 20.051 mm.
The speed is set to 10.025 m+a/s, which is 1/2 of A/s.

When set to this speed, the track pitch becomes 13.3 μm, and the rotating magnetic head is used for the standard speed of the NTSC system or a rotating magnetic head for 1/2 speed.

Furthermore, the width of the rotating magnetic head for 1/2 speed of the standard speed of the PAL system is within the range that allows recording and reproduction of audio signals and pilot signals, and tracking control using the crosstalk component of the pilot signal, making it possible to create a special width. This eliminates the need to use a rotating magnetic head.

When reproducing the audio signal recorded in this manner, the signal from the rotating magnetic head 1 is input to the reproducing amplifier 5 via the switch 2.3, and further supplied to the PCM decoder 12 via the switch 7. PCM decoder 1
2 is controlled by the CPU 33 and generates the clock f' from the reproduction signal.
Extract the channel and read the data of each part using it as a reference. The audio signal is converted into an analog signal and output. Further, a tracking pyrower 1 signal included in the reproduced signal is input to the tracking control circuit 32, and a tracking error signal is generated.

This tracking error signal is output to the adder circuit 30 via the switch 34, and tracking control is performed.

In other words, in R-DAT, as is clear from Table 1, a tracking signal (ATI-') is recorded before and after the PCM audio signal recording section, and crosstalk from that part of the left and right tracks is The components are sampled and held at a predetermined timing, and a tracking error signal is generated from the difference signal. However, in the present invention, as in the case of a normal 811II+ video tape recorder, continuous recording is performed on each track. A tracking error signal is generated from the difference signal of the crosstalk components from the left and right tracks of the pilot signal.

Table 3 Next, the data to be recorded in each area A through can be configured as shown in Table 3, for example. In other words, when the recorded information is a stereo audio signal, R, and the sampling frequency is 48kllz, and if consecutive numbers are assigned to a predetermined number of data (words) sampled by each clock, then the odd numbered L signal (Lo ) and even-numbered R signals (Re ) are in area A, and odd-numbered R signals (Ro
) and an even numbered L signal (Le) are respectively recorded in area A of the next adjacent track. That is, the data is interleaved on two tracks (and further interleaved within each track), and by obtaining the signals of the two tracks, complete data can be reproduced. Of course, if the advantage of using the same encoder and decoder as R-DAT is abandoned and a different encoder and decoder is used, such interleaving can be set arbitrarily. Similar records are in each area B.
,C.

In this case, information of two channels (L, R) can be recorded four times on one inclined track. Note that in Table 3, only data Lo and Re are listed for convenience (the same applies hereinafter).

Set the sampling frequency to 9, which is twice the reference frequency of 48kHz.
When the frequency is 6kHz, first the even numbered signals Le, Re,
It is divided into odd numbered signals Lo and Ro.

Then, a new order is assigned to the even-numbered signals Le and Re, and the same classification as described above is performed for the new order. In other words, the signal L whose new order is an odd number
o and the even numbered signal Rag are recorded in the area A, and the new odd numbered signal Ro and the even numbered signal Le are recorded in the next adjacent area A. And the signal L whose original order is an odd number
A new order is added to signals o and Ro, and the same processing is performed, but these signals are recorded in area B. As a result, the signal recorded in each area is substantially 48k) Iz
The signal is the same as that sampled at 48 kHz, and when decoded with a 48 kHz clock decoder, the same audio signal as sampled at 48 kHz can be reproduced. This becomes impossible if, for example, one piece of sampling data is divided into upper bits and lower bits and each bit is recorded in a different area.

Furthermore, the sampling frequency is set to 192, which is four times the reference frequency.
When converting to kHz, data is first divided into data groups of every four samples. For example, as shown in FIG. 5, the sampling values LL, R, at time t, the sampling values L2□, R21 four clocks later, and the sampling values L311 R31, etc. four clocks later, are as follows. One group. Similarly, sampling values L1□, R1□, L2□, R2°, L, 2. R, 2, etc. are taken as one group, and the sampling value L1. .

R1,,L12. R23, L33. Let R3n etc. be one group, and set the sampling values Li, , R machining, , R2i L
34. Let R14 etc. be one group. Then, the same processing as described above is performed so that each of these four groups is recorded in a different area A to each other. For example, by adding a new order in the first group, the odd-numbered signals Lo, , and the even-numbered signals (
No. 2 Re4 in area A, odd numbered signals r<o.

and even-numbered signal Le4 are respectively recorded in the next adjacent area A. As a result, in this case as well, as in the case described above, the signal recorded in each area becomes substantially equivalent to a signal sampled with a clock of the reference frequency, and reproduction using a decoder of the reference frequency becomes possible.

Similarly, if data is divided into data groups of every two samples, reproduction using a decoder with a frequency twice the reference frequency becomes possible.

Therefore, in any case, it is clear that it is preferable to make the recording area compatible with a lower sampling frequency.

Next, a case will be described in which, for example, front and rear audio signals (F, B) are added to the stereo audio signal (L, R) to record a four-channel audio signal. In this case, when the sampling frequency is set to the reference frequency of 48 kHz, left and right stereo signals (L, R) are sequentially recorded in area A, and corresponding front and rear signals (F, B) are recorded in area B, respectively. In principle, left and right audio signals (L
.

It is also possible to record audio signals (F, B) before and after (R) in one area. However, if you do that, you will have two channels of stereo signals (left and right signals (L, R).
))L, or playback becomes impossible on devices that cannot play. Therefore, the left and right signals (L, R) and the front and rear signals (F
, B) are preferably recorded in different areas. Left and right signals (L.

R) and front/rear signals (F, B) can be recorded in any area; the former can be recorded in areas B and A, and the latter can be recorded in areas C and D.
You can also record it in

In this case, since the left and right signals (L, R) and the front and back signals (F, B) can be recorded in areas C and D, respectively, information is recorded twice on one inclined track. In the above, the odd numbered signal Lo (Fo) and even numbered signal Re (Be) are recorded first in each area, and the odd numbered signal R is recorded in the next adjacent area.
o(r3o) and the even numbered signal Le(Fe)6
In this case, it can be arbitrarily determined in which area the left and right signals R and front and rear signals F and B are to be recorded.
The area where left and right signals and R are recorded is the area where R is recorded first or the area where R is recorded first or the area where R is recorded first or next with a sampling frequency of 96kHz. It is preferable to make each area correspond to each area.

96 times the standard frequency of the 4-channel audio signal
k) When sampling with Iz, the sampling values are first divided into odd-numbered sampling values , R, , F, , Bo and even-numbered sampling values Le, Re, Fe, and Be. And the odd number signal L0. RO, FOI Bl
, a new order is given to each of the even-numbered signals Le, Re, Fe, and Be. Odd number signal,
, R, the signal Lo4 whose new order is an odd number, and the signal Re4 whose new order is an even number are in the area A. Of the IRQs, a signal Ro4 whose new order is an odd number and a signal Le4 whose new order is an even number are recorded in the next adjacent area A. Similarly, signal F for odd numbers. , Bo, the signal Fo4 whose new order is an odd number, and the signal Be4 whose new order is an even number are in the region B, and the odd-numbered signals F, , B. Of these, the signal Bo whose new order is an odd number and the signal Fe4 whose new order is an even number are recorded in the next adjacent area B.

The signals Le, Re, Fe, Be at even times are as follows:
Recording is performed in areas C and D in the same manner. In this case as well, the areas for recording left and right signals, R, and front and rear signals F and B can be set arbitrarily, but in the case of standard frequency 2-channel stereo recording and standard frequency 4-channel recording It is preferable to make it correspond to That is, for example, the left and right signals of the sampling value of 48kHz, R
The left and right signals of the 96kHz sampling value are recorded in the same area where the left and right signals of the 96kHz sampling value are recorded. Faith > 3. 'F.

Record each item B. By doing this, 48
Even in a device that only has a +(z sampling clock), it is possible to reproduce the 411th sampling value of 96kl(z.In this case, information is recorded once on one inclined track. Become.

It is clear that if the recorded information is made into mutually independent information S to Z, eight channels of information can be recorded by sampling 48k)[z.

If it is necessary to further lengthen the recording wavelength, areas A and 8 may be used as one area, and areas C and I] may be used as one area.

The above description has been made assuming that the regions A to A are equivalent.

However, in reality, when recording and reproducing information using two rotating magnetic heads separated by 180 degrees from each other, areas A or D
In this case, when one rotating magnetic head is in contact with the magnetic tape, the other rotating magnetic head is also in contact with the magnetic tape. As a result, when one rotary head plays back information and the other rotary head records information (for example, after-recording), one piece of information overlaps with the other, resulting in increased noise.

It may become difficult to accurately record and reproduce information. Therefore, when reproducing information with one rotary head and recording information with the other rotary head, the more centrally located area B or C is reproduced, and the area A or D
It is preferable to record the For example, when recording 4-channel audio signals with standard frequency sampling, for example, at the first recording, areas A and D (or areas B and C) are paired as left and right signals, R and front and rear signals F.
, B are recorded, and during the second recording, areas 13 and C (or areas A and D) are paired as left and right signals, and R and front and rear signals F are recorded.
, B is preferably recorded.

Next, an embodiment of the PCM encoder 13 will be described.

For example, as shown in FIG.
It can be configured by a D converter 41 and a memory 42. The A/D converter 41 receives input left and right signals I1. R is converted from an analog signal to a digital signal according to a clock of a predetermined frequency (96! (z) in the embodiment) and stored in the memory 42. The signal stored in the memory 42 is read out according to a clock of the same frequency. At this time, for example, if the data read out at odd-numbered clocks is recorded in area A, and the data read out at even-numbered clocks is recorded in area B, the data recorded in each area can be sampled. The frequency becomes earth at 48.

Further, the same thing can be realized in an embodiment as shown in FIG. That is, in this embodiment, two systems of A/D converters 41 and memories 42 operating with a 48 kHz clock are prepared. The A/D converter 41B and memory 42B are supplied with 48 kl (
z clock (FIG. 8(b)) is supplied after being delayed by 180 degrees by the delay circuit 43 (FIG. 8(C)).

Therefore, for example, a predetermined analog signal (FIG. 8(a)) is sampled by 4 8 kHz sampling pulses having a mutual phase difference of 180 degrees, and each pulse corresponds to region A and B.
will be recorded. As a result, the original signal is essentially 9
This is equivalent to sampling at a frequency of 6kl (z).

FIG. 9 shows a PCM decoder 12 that decodes such a signal.
represents an example of In this embodiment, the reproduced signals from areas A and B (480 degrees out of phase with each other)
The signals (sampled by a kHz clock) are added by an adder circuit 51 to become a substantially 96 kHz sampling signal, which is then input to a D/A converter 52 . A 96 kHz clock is input to the D/A converter 52, and a digital signal read out according to this clock is smoothed by a low-pass filter 53 and output as an analog signal.

FIG. 10 shows another embodiment of the PCM decoder 12. In this embodiment, the D/A converter 52, which operates with a clock of 48k)lz, has two systems a(,A.

B) It is prepared. The outputs of the D/A converters 52A and 52B are supplied to a sample hold circuit 54, and the output thereof is further output to a low pass filter 53. D/A
A 48k) Iz clock is input to the converter 52A, and the clock is delayed by 180 degrees and input to the D/A converter 52F). Furthermore, this clock and a clock delayed by 180 degrees are supplied to the sample and hold circuit 54. For example, a reproduced signal from area A is converted from a digital signal to an analog signal by a D/A converter 52A (see FIG. 11). The reproduced signal from area B is converted from a digital signal to an analog signal by the D/A converter 52B (indicated by a broken line in FIG. 11), and is input to the sample and hold circuit 54. Sample hold circuit 54
is a clock that is not delayed, and sequentially samples and holds the output of the D/A converter 52A, such as levels a, l a, and t a3, and also samples and holds the output of the D/A converter 52B, such as level b, in response to the delayed clock. t bz etc. are sampled and held sequentially. The combined output is smoothed by a low-pass filter 53, and a yK multiplied signal (indicated by a dashed line in FIG. 11) is reproduced.

By preparing two systems of 48 kHz encoders or decoders in this way, it is possible to substantially record and reproduce a 96 kHz sampling signal without preparing a 96 kHz clock and its encoder or decoder.

In addition, the signal encoded by the encoder as described above and recorded in each area A or B is reproduced for each area, and the 48
Of course, it is possible to reproduce a 48 kHz sampling signal by decoding it with a kHz decoder.

〔effect〕

As described above, the present invention provides a magnetic recording/reproducing device in which a track formed by a rotating magnetic head at an angle with respect to the longitudinal direction of a magnetic tape is divided into a plurality of regions, and an analog signal is sampled with a clock having a frequency of 2f. When converted into a digital signal, the data sampled at odd-numbered clocks is recorded as one group in one area, and the data sampled at even-numbered clocks is recorded as one group in another area. , when an analog signal is sampled with a clock of frequency f and converted into a digital signal, the data sampled with one clock of frequency f is treated as one group, and the data sampled with the odd or even clock of frequency 2f is recorded. Since recording is done in the area corresponding to the clock frequency, not only can devices that operate with a higher frequency clock enjoy higher quality audio signals, but also devices that operate with a lower frequency clock can enjoy higher quality audio signals. Recorded signals can be played back.

[Brief explanation of drawings]

FIG. 1 is a block diagram of the magnetic recording/reproducing apparatus of the present invention, and FIG.
The figure is a schematic plan view of the track, FIG. 3 is a schematic plan view of the area, and FIG. 4 is a schematic plan view of the track in a conventional magnetic recording/reproducing device. 5 and 8 are schematic waveform diagrams representing the sampling state of the present invention, FIGS. 6 and 7 are block diagrams of the 20M encoder, FIGS. 9 and 10 are block diagrams of the PCM decoder, FIG. 11 is a schematic waveform diagram of the output signal. 1...Rotating magnetic head 2.3, 6, 7, 21, 34...Switch 4...Recording amplifier 5...Reproducing amplifier 8...Video modulator 9.13 "-" PCM encoder: L-da 10...Video demodulator 11.12...PCM decoder 14.23...Oscillator 15.25...Motor 16.26...Frequency generator 17...Pulse generator 18. 31...Drive circuit 19.27...Frequency control circuit 20.29...Phase control circuit 22...Synchronization separation circuit 24.30...Addition circuit 28...Frequency division circuit 32... Tracking control circuit 33...Central processing unit 35...Pilot signal generator 41...A/D converter 42...Memory 43.5
5...Delay circuit 51...Addition circuit 52...D/A converter 53.
...Low pass filter 54...More than sample hold circuit

Claims (1)

[Claims] When a track formed by a rotating magnetic head at an angle with respect to the longitudinal direction of the magnetic tape is divided into a plurality of regions, and an analog signal is sampled at a clock frequency of 2f and converted into a digital signal, an odd-numbered clock is used. The sampled data is recorded as one group in one of the areas, the data sampled at the even-numbered clock is recorded as one group in the other area, and the analog signal is recorded at a frequency f. When sampling with a clock and converting it into a digital signal, the data sampled with the clock of frequency f is treated as one group, and the data is converted into a digital signal with a frequency of 2.
A magnetic recording/reproducing apparatus characterized in that the data sampled at the odd-numbered or even-numbered clocks of f is recorded in the area corresponding to the area to be recorded.