JPS6050753A - Rotary head type recorder - Google Patents

Abstract

PURPOSE:To attain the recording with high fidelity while maintaining interchangeability a memory applying the conventional recording method, by recording the upper and lower data to different areas with the same rotary head when an analog information signal is converted into a digital signal. CONSTITUTION:An analog audio signal is sampled while heads 3 and 4 are moving to a point U from a point T, and the data of upper and lower 8-bits are stored to different memories respectively. The signal processing for generation of parity words, etc. is carried out while the heads 3 and 4 are moving to a point R from the point U. The data of upper 8-bit is recorded to an area 6a on a magnetic tape 1 while the heads 3 and 4 are moving to a point P from the point R. Then the data of lower 8-bit is recorded to an area 6b on the tape 1 while the heads 3 and 4 moving to a point T from the point P. When these recorded data are reproduced, a reproduction signal is obtained while the heads 3 and 4 is moving to the point T from the point R and stored to a memory. Then the reproduction signal processing for error correction, etc. is carried out while the heads 3 and 4 are moving from the point T to the point S. Furthermore, the data of 16-bit is read out and converted into analog signals while the heads 3 and 4 are moving to the point R from the point S. Thus a reproduction audio signal is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a rotary head type recording device, and more particularly to a device for recording a predetermined information signal in a predetermined area on a track sequentially formed on a recording medium by a rotary head.

(Description of the Prior Art) Recently, as a device of this type, a rotating two-head helical scan type video tape recorder (VTR) has a magnetic tape (180+l) in a rotating cylinder.

A method has been devised in which a PCM-converted and time-axis compressed audio signal is recorded on the portion wound above and around the θ inspection. FIG. 1 is a diagram showing a tape running system of a conventional VTR of this type, and FIG. 2 is a diagram showing a recording locus on a magnetic tape by the VTR shown in FIG. In the figure, 1 is a magnetic tape, 2 is a rotary cylinder, 6.4 is a head attached to the cylinder 2, 5 is a video area portion of a track formed on the tape 1, and 6 is an audio area portion. Video area 5 is rotary cylinder 2 (018
The part where head 6.4 traced the tape at 0' minutes, the audio area 6 is traced by head 3.4 at 00 minutes of rotating cylinder 2.
4 is the part where the tape was traced. However, if a guard band is provided between the video area 5 and the audio area 6, the audio area will be shortened accordingly.

FIG. 3 is a timing chart for explaining the operation of the VTR shown in FIG. 1. Figure 6 (1) is a rectangular wave signal synchronized with the rotation of cylinder 2. In a VTR based on the NT8C signal, cylinder 2 rotates 60 times per second, so it is a 30 Hz rectangular wave signal (hereinafter simply referred to as 30PG). become.

Assume that this 60PG rises when the head 6 passes point P in FIG. 1 and falls when it passes point Q. In addition, FIG. 6 (1) shows the phase of 30PG advanced by θ degrees, and it stands up when the head 6 passes the R point in FIG. 1 and falls when it passes the S point. do. Here, the dashed-dotted lines P and Q shown in FIG.
, L 8 are the points P, Q, 几, where the head 6 is shown in FIG.
It shows the timing of passing through S.

FIG. 6 Qn) shows the processing of the audio signal supplied to the head 3, and FIG. 6 Qv) shows the processing of the audio signal supplied to the head 4.

In the figure, 2 indicates the period during which the input audio signal is sampled, digitized, and stored in memory, and α indicates signal processing such as generation of error correction data (parity word) from the data stored in memory. W indicates the period during which the recording data thus obtained is read from the memory and recorded on the magnetic tape 1.

That is, as is clear from FIGS. 6(m) and (lv), the head 6
The process of obtaining time-axis compressed audio signals recorded by heads 4 includes sampling while each head is moving from point P to point Q, signal processing while moving from point Q to point R, and then sampled while moving from point P to point R. It will be recorded on tape 1 while moving from point R to point P.

On the other hand, FIG. 6 (■) shows how the audio signal played back by the head 3 is processed, and FIG. 6 (vl) shows how the audio signal played back by the head 4 is processed.

In the figure, r indicates the period in which the reproduced signal is obtained from tape 1 and stored in the memory, b indicates the period in which the reproduced signal processing such as decoding the parity word and error correction is performed, and 0 indicates the period in which the reproduced signal is processed from the memory. It is set to 1 to indicate the period for reading out the data and outputting the reproduced audio signal. That is, audio signals reproduced by the heads 3 and 4 are read from the magnetic tape 1 while the respective heads are moving from point R to point P, processed as reproduced signals while moving from point P to point S, and read out from the magnetic tape 1 while the heads are moving from point R to point P. While moving from point to point R, it is read out from memory and output. Therefore, all of these processings during recording and playback are shown in Figure 6 (1).
This can be done using a rectangular wave signal shown in (++).

By the way, when recording and reproducing an analog information signal by digitizing it, such as recording and reproducing a digital audio signal, points of interest in achieving high fidelity are the number of quantization bits and the sampling frequency.

The dynamic range 0 of the information signal to be recorded and reproduced is expressed as D-6M+1.8 (dl, where M is the number of quantization bits, and the upper limit σ of the frequency of the information signal to be recorded and reproduced is the sampling frequency fB. ,!: Then, it is expressed as fH-fs/2 (az).

Therefore, it is possible to increase the fidelity of the information signal by increasing the above M and fB, but in reality, it is restricted by the frequency characteristic band σD of the recording medium and device, so M and fB should not be increased unnecessarily. Can not. Now, the number of channels is C1, the number of withdrawn bits is M1, the redundancy is α, and the density conversion ratio (
data density/maximum inversion density) to DR lift pressure compression ratio to,
Assuming that the sampling frequency is fB and the frequency characteristic band of the recording medium and device is fD, at least the following condition must be satisfied in order to record and reproduce this digital signal.

fp)ts XMX fs XCXDRX (b)-f
B Therefore, M and fB are subject to the constraint of fD,
If fD is not large enough for fB, ts in the above equation
.

It is impossible to increase the fidelity of information signals recorded and reproduced except by changing C1α etc., that is, by changing the hardware part of the device.

(Object of the Invention) The present invention has been made against the above-mentioned background, and is intended to change the configuration of a conventional device of this kind when digitizing an analog information signal and recording it with a rotating head. An object of the present invention is to provide a rotary head type recording device that can perform high-fidelity recording while maintaining compatibility with conventional devices.

(Description of Embodiments) Hereinafter, the present invention will be described using an embodiment in which the present invention is applied to the above-mentioned rotary two-head Rechallus Gann type VTR. Note that the citation of the following examples does not limit the scope of the present invention, and the present invention can be modified as appropriate within the scope of the claims.

First, the basic idea of the present invention will be explained with respect to the above-mentioned VTR.

This will be explained by taking as an example the case where it is applied to. 4th Spring).

(C) is a diagram for explaining the basic idea of the present invention. The components shown in FIG. 1 or 2 share the same numbering.

As shown in the figure, tape 1 is attached to rotating cylinder 2 (180°+00
When winding and using it as a VTR, it is exactly the same as before.
While the heads 3 and 4 move from the illustrated point to the point P by θ0, a time-base compressed audio signal is recorded, and the head 6.
4 records a video signal while moving 1800 degrees from point P to point Q as shown. That is, the time axis compressed audio signal is recorded in the area 6 & shown in ) in FIG.
A video signal will be recorded in the other part.

The idea of the present invention is that when used as an audio-only device, when an analog audio signal is converted into a digital signal, the information signal containing the upper data is placed in the area 6a, and the information signal containing the lower data is placed on the track 5 such as the area 6b. This is where the data is recorded in another predetermined area. That is, for example, while the heads 3 and 4 are moving from point T to point U shown in FIG. 4 (8), the analog audio signal is sampled, and the upper 8 bit data and lower 8 bit data are respectively stored in separate memories. I'll do it. Then, while moving from point U to point R, signal processing such as generation of a parity word is performed for each point, and while moving from point R to point P, recording data obtained from the upper 8 bits of data is read from the memory and recorded on the magnetic tape. 1
The recording data is recorded in the upper area 6a, and the recording data obtained from the lower 8 bits while moving from point P to point T is read out from the memory and recorded in the area 6b on the magnetic tape 1.

On the other hand, when reproducing this, heads 3 and 4 move from point R to point T.
While moving, a playback signal is obtained and stored in memory. Then, reproduction signal processing such as error correction is performed on the data recorded in area 6a and the data recorded in area 6b while moving from point T to point S, respectively. Furthermore, while moving from point S to point R, it is read out as 16-bit data and converted into an analog signal to obtain a reproduced audio signal.

In order to operate as described above, the analog-to-digital converter (A/D) and digital-to-analog converter (D/A) of the conventional VTR are made double-precision (compatible with 16 bits), and the memory is This can be achieved by simply doubling the (RAM) capacity and creating the required control clock.

A circuit configuration for realizing the above-described device will be explained below. FIG. 5 is a diagram showing the circuit configuration of a device as an embodiment of the present invention. In FIG. 5, 11 is an audio signal input terminal 112 is an audio signal output terminal, 16 is a video signal input terminal, 14 is a video signal output terminal, 15 is a low pass filter (IJPF), and 16 is a sample hold circuit @A , 17 is an analog-to-digital converter~phrase, 18 is a digital-to-analog converter G)
/A), 19 is a path selector. 20 and 21 are RAM memories, respectively, and R and A M -A respectively.

R, AM-B. 22 is an up counter or down counter, 23 is an addressing circuit for interleaving data when storing data, 24 is a parallel-to-serial (ps) conversion circuit, and 25 is a digital signal processing circuit including generation of a parity word. . 26 is a digital signal recording processing section, which includes, for example, a well-known digital modulation circuit and a circuit with a synchronizing signal pattern. On the other hand, 27 is a digital signal reproduction processing section, which includes a digital demodulation circuit, a bit synchronization circuit, a synchronization signal pattern separation circuit, and the like.

2B is a recording amplifier for audio signals, 29 is a playback amplifier for audio signals, 60 is a recording amplifier for video signals, 3
1 is a video signal reproduction amplifier, 62 is a head control circuit, 35 is a rotating cylinder, 66 is a cylinder PG control circuit that generates a 6-relaxation pulse signal (30PG) synchronized with the rotation of the cylinder 65, and 67 is an operation of the device. A mode selector designates a mode, 38 is a control clock generation circuit, and 69 is a crystal oscillator.

The operation will be explained below. First, the operation when used as a VTR and records a digital audio signal in the area 6a shown in FIG. 4 will be described. The analog audio signal input from terminal 11 is passed through LPF 15 to 8/
4 (sampled and held at 16 and IVf) and quantized at 17 to become a 16-bit digital signal. The quantized digital audio data is sequentially stored in RAM-A20 DEG RAM-B21 via the path selector 19 every one field time, that is, every 1800 rotations of the cylinder. Figure 4 (5).

To explain in response to (b), the head 6 moves from point T to point U.
While the head 4 is moving from point T to point U, 16-bit digital audio data is stored in RAM-B21.
Stores bits of digital audio data.

While data is being stored in RAM-B 21, data generally stored in RAM-A 20 is signal-processed by digital signal processing circuit 25 via path selector 19. This signal processing is 16 obtained with N width 17
This is performed for the upper 8 bits of data and the lower 8 bits of the bit digital signal. This upper 8-bit data is exactly the same as that from a conventional VTR, and the signal is an 8-bit quantized audio signal itself. These signal processing U
This is performed while the head 6 is moving from the point U to the point R for the data stored in the RAM-A 20, and the head 4 is moving the data stored in the RAM-821 from the point U to the point R, respectively.

The data processed in this way is then transferred to the P-8 conversion shift register via the path selector 19, and further transferred to the digital signal recording processing section 26 where digital modulation, synchronization signal pattern addition, etc. are performed, and the data is recorded. Amplifier 2
8 to the head controller) o-, 21/circuit 32. Regarding the timing of this transfer, RAM −
The data corresponding to the upper 8 bits stored in A20 is carried out while the head 3 is moving from point R to point P, and the data corresponding to the lower 8 bits is carried out while the head 3 is moving from point P to point T. , the head 4 is moving from point R to point P for the data corresponding to the upper 8 bits stored in RAM-B21, and the head 4 is moving from point P to point T for the data corresponding to the lower 8 bits. It will be held on.

When used as a VTR, the head control circuit 32 supplies a signal from the recording amplifier 2B to each head 6.4 while the head 6.4 is moving from point R to point B. Also V
When used as a TI, the audio signal is naturally recorded in the area 6a shown in Figure 4, but at this time, the video signal input from the video signal input terminal 13 is processed by the video signal processing circuit 40, and then sent to the recording amplifier. 60. It is supplied to the head 66 or head 64 via the head control circuit 32. Of course, this video signal is supplied while each head is moving from point P to point Q shown in FIG. 4(5).

Next, the operation during playback when used as a VTR will be explained. Audio signals recorded while each head in the area 6a moves from point R to point P from the playback output of the head 6.4 are sent to the playback amplifier 3 via the head control circuit 32.
1 and then transferred to the digital signal reproduction processing section 27, where bit synchronization, synchronization signal pattern separation, digital demodulation, etc. are performed. The signal processed by the processing unit 27 is subsequently serial-parallel converted by the P-8 conversion shift register 24, and then sent to the RAM via the path selector 19.
-A20 and is supplied to RAM-B21.

This data is processed by the digital signal processing circuit 25 such as error correction while each head is moving from point T to point S, and then stored in the RAM-A2 while each head is moving from point S to point R.
0. The time axis is expanded and taken out from RAM-821,
The 8-bit digital signal is converted back to an analog signal by the D/A 18, deglitched by the S/H 16, and then sent to the LPF 1.
5 and is returned to an analog audio signal.

On the other hand, the video signal recorded in a portion other than the area 6IL of each track 5 is made into a continuous signal by the head control circuit 32, returned to the original signal form by the video signal processing circuit 40, and outputted from the output terminal 14.

Next, the operation when recording a 16-bit digital signal as an audio-only device will be explained. The signal processing of the audio signal is exactly the same as when used as the VTR mentioned above, and the data corresponding to the upper 8 bits is supplied to the head control circuit 62 while each head is moving from point A to point P, and the lower Data corresponding to 8 bits is supplied to the head control circuit 62 while each head is moving from point P to point T. Then, the head control circuit 62 cuts off the video signal recording amplifier 60 and the head 6.4, and the audio signal recording amplifier 2
All data supplied from head 8 is supplied to head 6 or 4. By doing this, as shown in Figure 4 (b),
The data corresponding to the upper 8 bits in area 6a is in area 6b.
Data corresponding to the lower 8 bits is recorded.

Next, the operation during playback will be explained. The data corresponding to the upper 8 bits and the data corresponding to the lower 8 bits reproduced while each head 3.4 moves from point R to point T are transferred to the reproduction amplifier 29. Reproduction digital signal processing circuit 27. p-s conversion circuit 24. The data reproduced by the head 6 via the path selector 19 is stored in the RAM-A20, and the data reproduced by the head 4 is stored in the It, AM-821.

RAM-A20. The data stored in the RAM-B 21 is subjected to error correction processing and the like in the digital signal processing circuit 25 while the heads 3 and 4 are moving from point T to point S, respectively. Then, while each head 5, 4 is moving from point S to point R, R
, A M -A20. 1 each from RAM-B21
It is read out as a 6-bit digital signal and sent to D/A1.
B, 8, 4 (16, LPF'i) It is outputted from the output terminal 12 via 5 as a high-fidelity analog audio signal.

FIG. 6 is a timing chart showing the operation when the device shown in FIG. 5 is used as an audio-only device. Figure 6 (+) is 3QPG obtained by the cylinder PG generation circuit 66, Figure 6 (It) is the phase of 3 [IPG advanced by θ0, Figure 6 6u) is the phase of 3 []PG delayed by 00. It is something that In addition, the dashed-dotted lines P, Q, R shown in FIG.
, S, T, and U are the points p shown in FIG.
, Q, R, 8, T, and U.

FIG. 6GV) shows how the audio signal supplied to the head 6 is processed, and FIG. 6 (■) shows how the audio signal supplied to the head 4 is processed.

In the figure, 8 indicates a period in which the digital signal processing circuit 25 performs signal processing such as sampling the input analog audio signal to create a 16-bit digital signal, and 8 indicates the period in which the digital signal processing circuit 25 performs signal processing such as sampling the input analog audio signal and creating a code as a 16-bit digital signal. It shows a period in which data is recorded in the area 6a shown in FIG. 40, and the second one shows a period in which data corresponding to the lower 8 bits is recorded in the area 6b shown in FIG. 40.

On the other hand, FIG. 6 (Vl) shows how the audio signal reproduced by the head 6 is processed, and FIG. In the figure, r1 is area 6! r2 indicates a period for obtaining playback data corresponding to the upper 8 bits from L and storing it in the RAM, r2 indicates a period for obtaining playback data corresponding to the lower 8 bits from the area 6b and storing it in FLAM, and b indicates a period for storing the playback data in the RAM. Indicates the period in which the digital signal processing circuit 25 performs signal processing such as decoding the parity words of the upper 8 bits and lower 8 bits of the stored data and performing error correction. This shows a period during which the data is sequentially read out as a 16-bit digital audio signal and a high-fidelity reproduced analog audio signal is output.

According to the apparatus constructed as described above, a conventional VTR as shown in FIG. 1 can be utilized extremely efficiently, and a highly faithful audio recording and reproducing apparatus can be obtained. Also, the conventional V
Since digital audio signals recorded with 'L'R' can be recorded in the same location and in the same signal format, digital audio signals recorded with the audio-dedicated device obtained by the present invention can also be played back as 8-bit digital audio signals with a conventional VTR. It also provides complete compatibility.

Note that the RAM may be provided separately for upper data and lower data.

By the way, when the above-mentioned device is used as an audio-only device, recording is performed only in areas 6a and 6b as shown in FIG. . Now if θ=600, then 1500
This means that there will be a portion where nothing is recorded in the minute portion. Therefore, let's consider a device that can record even this unrecorded portion and perform multi-channel audio recording and playback.

Figure 7 is a diagram for explaining the concept of multi-channeling. Each point P, Q shown in FIG. 7 (5).

It is assumed that R, S, T, U, A, B, C, D, E, and F are points having a phase difference of 60° around the cylinder 2.

Now, when recording is performed while the heads 4 are moving from point R to point P, the recording signal will be in the area 6! shown in ) in FIG. It will be recorded in L. Similarly, when going from point P to point T, it is recorded in area 6b, and when going from point T to point A, it is recorded in area 6c,
Region 6d, 6θ.

The same applies to 6f and 6g. Now, when used as an audio-only device in the position shown in FIG.
If the audio signal is recorded with a phase shift, data corresponding to the upper 8 bits will be recorded in the area 6o, and data corresponding to the lower 8 bits will be recorded in the area 6d. Furthermore, if the generation phase of 30PG is further shifted by 6o0 and an audio signal is recorded, the data corresponding to the upper 8 bits will be recorded in the area 6e, and the data corresponding to the lower 8 bits will be recorded in the area 6f. Ru.

With this configuration, it is possible to record six channels of high-fidelity 16-bit digital audio signals. Similarly, reproduction can be performed simply by changing the generation phase of 30PG.

Furthermore, if configured in this manner, a device capable of recording and reproducing an 8-bit digital audio signal in each area and a device capable of recording and reproducing an 8-bit digital audio signal as described in Japanese Patent Application No. 58-75861 previously filed by the present applicant and the upper 8 bits can be used. Compatibility can be obtained with respect to the area in which data corresponding to the number of minutes is recorded and reproduced. Furthermore, if the head control circuit 32 prevents the lower 8 bits of data from being supplied to the head, 8-bit recording becomes possible, so 8-bit digital audio signals are recorded in the 7 channels of areas 6a to 6g. You can also make it possible.

By the way, when multi-channel recording is performed in a case where the tape is used as an audio-only machine, each time recording is completed to the end of the tape, it is necessary to rewind and record the next channel. Therefore, a suitable countermeasure is to reverse the direction of rotation of the cylinder 2 and the direction of transport of the tape 1 for each adjacent channel. For example, a 16-bit digital audio signal is recorded by recording data corresponding to the upper 8 bits in area 6a and data corresponding to the lower 8 bits in area 6b, and after recording to the end of the tape, turn the tape in the opposite direction. A 16-bit digital audio signal can be recorded by rotating the cylinder 2 in the opposite direction and recording data corresponding to the upper 8 bits in the area 6d and data corresponding to the lower 8 bits in the area 6o. In this way, when the number of channels is increased, reciprocating recording can be easily performed. Of course, reciprocal recording can be similarly performed when only data corresponding to the upper 8 bits are recorded in each area.

(Description of Effects) As explained above using the embodiments, according to the present invention, when an analog information signal is digitized, upper data and lower data can be recorded in different areas using the same rotating head. Accordingly, it is possible to obtain a rotary head type recording device that can perform high-fidelity recording while maintaining compatibility with devices using conventional recording methods.

[Brief Description of the Drawings] Figure 1 is a diagram showing the tape running system of a conventional VTR, Figure 2 is a diagram showing the recording trajectory on the magnetic tape by the VTR shown in Figure 1, and Figure 6 is the diagram shown in Figure 1. Figure 4 (g), ■) is a diagram for explaining the basic idea of the claimed invention, Figure 5 is a device as an embodiment of the claimed invention. Figure 6 is a timing chart showing the operation when the device shown in Figure 5 is used as an audio-only device, Figure 7 (2) l@ explains the concept of multi-channeling. This is a diagram for 1 is a magnetic tape, 2 is a rotating cylinder, 6 and 4 are heads, 5 is a track, 6a to 6g are respective areas, 17 is an analog-to-digital converter, 20 and 21 are RAMs, 25 is a digital data signal processing circuit, 62 is a head control circuit, 36 is a cylinder PG monitoring circuit, 67 is a mode selector, and 68 is a control clock generation circuit. Applicant: Gyanon Co., Ltd.

Claims (1)

[Claims] 1) An apparatus for sequentially (forming a rack) recording on a recording medium using a rotating head, which includes means for converting an analog information signal into a digital signal, and a third apparatus containing higher-order data of the digital signal obtained by the converting means. means for obtaining a first information signal and a second information signal including lower-order data;
and means for recording the second information signal in different predetermined areas on each of the tracks.