JPS6262401A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To attain the recording and reproducing of a high definition audio signal by rotating a rotating magnetic head switching from the first speed to the second one, dividing an oblique track constituted with the first and the second portions to four areas and recording and reproducing information consisting of from the eighth to tenth portions on each of the four areas. CONSTITUTION:In the reproducing time of a video signal, the output signal of an oscillator 23 is supplied to a phase control circuit 20 through a switch 21 as a reference signal. Also, a switch 34 is switched to a tracking control circuit 32 side, and the phase servo of a motor 25 is performed against a track ing error signal generated from the cross talk component of a pilot signal recorded on a track neighboring at the right and left. A reproducing signal from a rotating magnetic head 1 is inputted to a video demodulator 10 and a PCM decoder 11 through switches 2 and 3, a reproducing amplifier 5 and a switch 7. Therefore, each of the video signal recorded on a video signal record ing part of 180 degrees and the audio signal recorded on an audio signal record ing part of 36 degrees is demodulated and outputted respectively.

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]

According to the present invention, a rotary magnetic head rotated at a first speed is used to attach a first track to a track inclined with respect to the longitudinal direction of a magnetic tape.
and a second part, and at least the first part is further divided into a part a in which a clock signal is recorded, a part in which data such as a PCM audio signal is recorded, and a margin part for after-recording. C, and a video overlap section d where the video signal of the immediately previous field is continuously recorded, and P is divided into the first section or the second section.
In a magnetic recording and reproducing device that records or reproduces a CM audio signal or video signal by frequency multiplexing it with a pilot signal for tracking, the length of the magnetic tape is A third part for recording the first code signal, a fourth part for recording a control signal for tracking, a fifth part for recording a PCM audio signal, and a third part for recording the first code signal on a track inclined with respect to the direction. A sixth part for recording a control signal for the second code signal and a seventh part for recording a second code signal are formed, and a predetermined number of blocks of data are recorded and reproduced in each of the third to seventh parts. An eighth part records a third code signal with the same number of blocks as in the third part, and a ninth part records a PCM audio signal with the same number of blocks as in the fifth part. forming a tenth part recording a fourth code signal of the same number of blocks as in the seventh part;
When the rotating magnetic head is switched from the first speed to the second speed and rotated, the inclined track consisting of the first part and the second part is divided into four regions, and each of the four regions has a Information consisting of the eighth, ninth and tenth parts is recorded and reproduced, thereby making it possible to record and reproduce higher quality audio signals in a so-called 81m1 video tape recorder.

[Conventional technology]

Recently, so-called 8m video tape recorders have been standardized and commercialized. In this 8+nm video tape recorder, the rotating diameter of the rotating magnetic head (the diameter of the rotating drum) is 40 mm, 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 section into more detail, there is a section A where the clock signal is recorded, a section where data such as PC and M audio signals are recorded, a margin section C for after-recording, and the immediately preceding field. and a video overlap section d in which the video signals of 1 and 2 are continuously recorded. Then, tracking pilot signals f1, f, , fl, and f4 are sequentially recorded for each track in the entire portion corresponding to the winding angle of 221 degrees. These pilot signals f
1, f2, fl, f4.

For example, fH158, f1150, f, /36, f
The signal is H/40 (fl+ is a horizontal synchronization signal). A tracking error signal is generated from crosstalk components from the left and right tracks of the pilot signal continuously recorded on each track. The rotation speed of the rotating magnetic head is 1 in the NTSC system because it records video signals.
800 rpm, 1500 p p in PAL system
It is said that m. 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 has a sampling frequency of 2fH (approximately 31.5kHz) and a quantization bit count of 10 bits (however, 10-bit data is converted to 8-bit data and recorded on magnetic tape). ), 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 magnetic tape winding angle is 90 degrees, the diameter of the drum is 30 strokes, and the sampling frequency is 4.
8k) (z, 44.1, 7, or 32kHz, 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.

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

As can be seen from Table 1, this data mainly consists of parts 2.3.
4, and a tracking signal recording section consisting of sections 5, 6, and 7.

It is composed of a PCM audio signal recording section consisting of sections 8.9, a tracking signal recording section consisting of sections 10.11.12, and a subcode signal recording section consisting of sections 13.14.15.

Table 1 [Problems to be Solved by the Invention] As described above, there are two methods for recording and reproducing digital audio signals on a magnetic tape using a rotating magnetic head. Since the main purpose is to record signals, the sampling frequency of audio signals is low, and R-DA
It had the disadvantage of inferior sound quality compared to the T. 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 nm video tape recorder) according to the present invention.

In the figure, 1 is a rotating drum (
(not disclosed), 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 a regenerative amplifier 5 via a 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. Further, the signal from the regenerative amplifier 5 is outputted to the video demodulator 1o and the PCM decoder 11 via the switch 7. 12 and 13 are a PCM decoder and a PCM encoder compatible with the R-DAT format; the signal from the regenerative amplifier 5 is supplied to the PCM decoder 12 via the switch 7, and the output of the PCM encoder 13 is connected to the switch 6. The signal is supplied to the recording amplifier 4 via the recording amplifier 4. An oscillator 14 generates a clock signal f''ch and outputs it to the PCM encoder 13.

15 is a motor that rotates the rotating drum.

It includes a frequency generator 16 and a pulse generator 17, and is driven by a drive circuit 18. The output of the frequency power generation Ja16 is input to the frequency control circuit 19.

It is compared with a predetermined reference signal output by a built-in oscillation circuit, and an error signal thereof is output. 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. Any of the reference signals to be output is input as a reference signal via the switch 21.

The phase is compared with the pulse output from the pulse generator 17, and a signal corresponding to the error is output.

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 uses a predetermined reference signal output from a built-in oscillation circuit and the frequency generator 2.
6 and outputs the error signal to the adder circuit 30. 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 compares the signal from the switch 21 and the signal from the frequency divider circuit 28 and outputs the error signal to the adder circuit 30 via the switch 34. 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 circuit 19.27,
A control signal is sent to the drive circuit 18.
ppm (1500 rPm in the case of 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 six-phase control circuit 20 rotates the rotary drum in synchronization with the phase of the vertical synchronization signal in the video signal to be recorded. A head switching pulse (H8WP), which is a reference for switching the rotating magnetic head, is generated and output 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)
．． 345m/s, 20.051m/s for PAL method
) The speed of the magnetic tape is controlled so that

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 a zero phase control circuit 20 recorded on the magnetic tape.
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.
It is input to the CM 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.

Next, when recording only high-quality audio signals, 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.

In Table 2, in accordance with the present invention, one track of length corresponding to a winding angle of 221 degrees is 54 mm as shown in FIG.
Divided into four areas of degree length.

Extra portions of 2.044 degrees and 2.956 degrees are provided on the left and right sides thereof. The 54-degree length area A is further divided into nine parts as shown in FIG. 3, and 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, and the last margin section 16 are removed. Further, the clock f'ch here is, for example, 12.864MHz (=0.0
48M7 x 268). This frequency is the audio signal sampling frequency 48kllz (=0.04
8M7), and is appropriately selected from a value near the highest recording frequency. Of course, the combination can be changed as long as the winding angle of 54 degrees and the recording time of 4500 μs are maintained. For example, a 2-block PLL
(PCM) Eliminate the clock recording section and increase the margin section to 8.
It is also possible to change from 8 to 10.8 blocks. 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 1
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 rotary magnetic head 1 via the switch 2.3° 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 and the drive circuit 18 are controlled by the CPU 33 to rotate the rotary drum at 200 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, Standard speed for PAL system is 20.051m/s
The speed of 172 is set to 10.025 m/s.

When set to this speed, the track pitch becomes 13.3 μm, and it is possible to use a rotary magnetic head for standard/standard speed of the NTSC system or a rotary magnetic head for 1/2 speed of the standard speed of the NTSC system, and a rotary magnetic head for 1/2 speed of the standard speed of the PAL system. The width of the rotating magnetic head is
The range is from 1.5 times to twice the track pitch (13.3 μm). Therefore, it is possible to record and reproduce audio signals and pilot signals without using a rotating magnetic head with a special width, and it is also possible to perform tracking control using the crosstalk component of the pilot signal.

When reproducing an audio signal recorded in this manner, a signal from the one-rotation magnetic head 1 is inputted to a reproducing amplifier 5 via switches 2 and 3, and further supplied to a PCM decoder 12 via a 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 to an analog signal and processed. Further, a pilot signal for tracking included in the reproduced signal is input to the tracking control circuit 32,
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, there is a track before and after the PCM audio signal recording section.
A tracking signal (ATF) is recorded, and the crosstalk components of that part of the left and right tracks are sampled and held at a predetermined timing, and a tracking error signal is generated from the difference signal. In the present invention, a tracking error signal is generated from the difference signal of crosstalk components from the left and right tracks of pilot signals continuously recorded on each track, as in the case of a normal 81W video tape recorder.

In the same manner as R-DAT, audio signals of 16 bits each and two left and right channels are mixed and recorded on one track in the four areas A to A. Therefore, for example, if the running direction of the magnetic tape is reversed for each area, and areas A and C are used as recording/playback areas for forward feeding and areas B and D are used for reverse feeding, then four areas will be formed. Tracks can be recorded and played back continuously.

For example, if areas A and C are used for the left channel and areas B and D are used for the right channel, the left and right channels can be recorded and reproduced independently.

By doubling the sampling frequency (96kl(z)) and recording and reproducing the upper 8 bits and lower 8 bits of data, or the left and right channel data for each area, it is possible to record and reproduce higher quality audio signals. Furthermore, it is possible to quadruple the sampling frequency and record and reproduce data of every 4 bits in each area.In addition, 4 channels with 2 areas as a set, 6 channels with 3 areas as a set,
It is also possible to have 8 channels each consisting of 4 areas.

〔effect〕

As described above, the present invention forms a first portion and a second portion on a track inclined with respect to the longitudinal direction of a magnetic tape by a rotating magnetic head rotated at a first speed, and forms at least a first portion. Furthermore, there is a part a where a clock signal is recorded, a part where data such as a PCM audio signal is recorded, and a margin part C for after-recording.
It is divided into a video overlap part d in which the video signal of the immediately previous field is continuously recorded, and a first part or a second part.
In a magnetic recording and reproducing device that records or reproduces a PCM audio signal or a video signal by frequency multiplexing it with a pilot signal for tracking, a rotating magnetic head rotates at a second speed faster than the first speed. A third part for recording a first code signal, a fourth part for recording a tracking control signal, and a fifth part for recording a PCM audio signal on a track inclined with respect to the longitudinal direction of the magnetic tape. a sixth part for recording a tracking control signal, and a seventh part for recording a second code signal, and a predetermined number of blocks of data are recorded in each of the third to seventh parts. An eighth part records a third code signal with the same number of blocks as in the third part, and a PCM audio signal with the same number of blocks as in the fifth part. forming a ninth section for recording and a tenth section for recording a fourth code signal of the same number of blocks as in the seventh section, and changing the rotating magnetic head from the first speed to the second speed; Switch and rotate the first part and the second part.
Divide the inclined track into four areas,
In each of the four areas, the eighth. Since the information consisting of the ninth and tenth parts is recorded and reproduced, the so-called 8m video tape recorder can record and reproduce not only video signals but also high-quality (hi-fi) audio signals.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of the magnetic recording/reproducing apparatus of the present invention, FIG. 2 is a schematic plan view of its tracks, FIG. 3 is a schematic plan view of its area, and FIG. 4 is a conventional magnetic recording/reproducing apparatus. 1 is a schematic plan view of a track in 1... Rotating magnetic head 2.3, 6, 7, 21, 34... Switch 4... Recording amplifier 5... Reproducing amplifier 8... Video modulation equipment 9.13...P CM encoder 1o...video demodulator 11.12...P CM 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 dividing circuit 32...Tracking control circuit 33...Central processing unit 35...Pilot signal generator or higher

Claims (6)

[Claims] (1) A first portion and a second portion are formed on a track inclined with respect to the longitudinal direction of the magnetic tape by a rotating magnetic head rotated at a first speed, and at least the first portion is further clocked. A section a where signals are recorded, a section b where data such as PCM audio signals are recorded, a margin section c for after-recording, and a video overlap section where the video signal of the immediately previous field is continuously recorded. d, and records or reproduces a PCM audio signal or video signal in the first part or the second part by frequency multiplexing it with a pilot signal for tracking. A third portion for recording the first code signal and a tracking control signal are recorded on a track inclined with respect to the longitudinal direction of the magnetic tape by a rotating magnetic head rotated at a second speed faster than the second speed. a fourth part, a fifth part for recording a PCM audio signal, a sixth part for recording a tracking control signal, and a seventh part for recording a second code signal; an eighth part for recording a third code signal in the same number of blocks as in the third part, corresponding to a method for recording and reproducing data of a predetermined number of blocks in each of the third to seventh parts; and a ninth portion for recording a PCM audio signal having the same number of blocks as in the fifth portion; and a tenth portion for recording a fourth code signal having the same number of blocks as in the seventh portion. and rotating the rotating magnetic head by switching from the first speed to the second speed, and dividing the inclined track consisting of the first portion and the second portion into four regions. divided,
A magnetic recording and reproducing apparatus characterized in that information consisting of the eighth, ninth and tenth parts is frequency-multiplexed with the pilot signal for tracking and is recorded and reproduced in each of the four areas. (2) The running speed of the magnetic tape is such that the PCM audio signal and the video signal are transmitted to the first portion and the second portion.
2. The magnetic recording and reproducing apparatus according to claim 1, wherein the magnetic recording and reproducing apparatus has a speed that is 1/2 of the standard speed when recording and reproducing in the AL system. (3) Claim 1, characterized in that the audio signal having a sampling frequency twice the sampling frequency of the audio signal recorded in the fifth portion is recorded and reproduced in the two areas. Or the magnetic recording and reproducing device according to item 2. (4) Claim 1, characterized in that the audio signal having a sampling frequency four times as high as the sampling frequency of the audio signal recorded in the fifth portion is recorded and reproduced in the four areas. Or the magnetic recording and reproducing device according to item 2. (5) Magnetic recording and reproducing according to any one of claims 1 to 4, characterized in that only one audio signal of the left or right channel is recorded and reproduced in one area. Device. (6) The pilot signal is characterized in that it has the same frequency as the pilot signal when recording and reproducing the PCM audio signal and the video signal in the first part and the second part in the PAL system. A magnetic recording and reproducing device according to any one of claims 1 to 5.