JPS61104369A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To record and reproduce several kinds of signal with pairs of video and audio signals by dividing one track to even sectors and recording the audio signal on one of a pair of two sectors and recording information related to the audio signal on the other. CONSTITUTION:The composite video signal inputted from an input terminal 7 passes an A/D converter 9 and a scan converter 10 and is sent to a video controller 12 and is written temporarily in a memory 11 and is sent to a modulating circuit 13 simultaneously. Meanwhile, R and L-channel audio signals inputted from input terminals 25 and 26 are inputted to an audio controller 32 through an A/D converter 29 and are written in memories 30 and 31 and are sent to a modulator 33 simultaneously. Outputs of modulators 13 and 33 are sent to a switch 14 and are switched by the output of a pulse generator 51 and are added to the output of a pilot generator 47 by an adder 15, and the audio signal and the video signal are recorded on one and the other of each pair of sectors of 6 sectors, which one track is divided to, respectively through gate circuits 16 and 18 and recording amplifiers 17 and 19 by rotary heads 20 and 21.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a magnetic recording and reproducing device, which converts information signals such as video signals and audio signals into PCM, and converts information signals such as video signals and audio signals into PCM.
The present invention relates to a method for recording commercial information signals on a tape using a rotary head, and more particularly to a method for dividing each discontinuous recording track into a plurality of sectors and recording the signal in each sector.

Conventional configuration and its problems Conventionally, the recording track of a helical scan type magnetic recording/reproducing device is divided into multiple sectors and recorded.
It has been proposed in Japanese Patent Application Laid-Open No. 58-222402,
When used for audio purposes, it is only proposed that it be used only as a tape recorder. If the device is capable of recording still image signals as well as audio signals, its uses can be further expanded.

Purpose of the Invention An object of the present invention is to divide one track into a plurality of sectors and transmit information signals such as video signals and audio signals to a PC.
The object of the present invention is to provide a system that can record and reproduce several types of signals using video and audio signal pairs.

Structure of the Invention The magnetic recording/reproducing device of the present invention winds a magnetic tape diagonally around a cylinder containing a rotating head, records information signals as a group of discontinuous recording tracks, and divides one track into an even number of sectors. It is configured to record and reproduce two sectors as a set, and stores the signal for one frame of the video signal from the video signal input terminal in the scan converter, and the signal stored in the scan converter and the signal stored in the scan converter. The signal input from the audio signal input terminal is compressed in the time axis, and the signal is simultaneously recorded in independent sectors, making it possible to record several pairs of still images and audio signals.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is an example of a pattern diagram of the present invention, taking an 8 mm video as an example, where arrow 1 indicates the rotation direction of the rotary head and arrow 2 indicates the running direction of the tape.

3 is the full width of the tape, 4 is a portion recorded with a rotating head, 6 is a track on which an audio signal is recorded with a fixed head, and 6 is a track on which a cue signal is recorded with a fixed head. Normal BL
A video signal is recorded at 1800 positions from 2-A1 to BLe-AI, and a time-axis compressed audio signal is recorded at the BLl-AI position. Also, if you divide this 180 minutes into 5 equal parts, BLl
- 0 which is the same as A1 By doing this, one track can be divided into 6 sectors. Now, a method for recording a still image in BLs and an audio signal in BL4 among the six sectors BL1 to BLe will be explained.

BLa-A1. BLs-B1. If a still image is to be recorded in the BLs-A2 section, it is necessary to determine the capacity that can be recorded in the BLs section of one trunk.

According to the 8mm video standard (NTSC), the data is
Two samples, 2 channels of R and L, are recorded during 1H. A/
The D conversion data is 10 bits, but since it is converted by 10-8, the total amount of recorded data is 8/1 rack after conversion, and the total amount of recorded data including additional if information such as address and parity is 14
, 124 bits/1 rack. However, this part does not include the postamble or preamble.

Next, an encoding method for determining the RAM capacity in the scan converter will be explained.

The vertical blanking period in the video signal is approximately 21H (horizontal synchronization signal interval), so as shown in Figure 2, 18.5H is a non-recorded portion, and the remaining 244H of the video portion is
Suppose that H minutes are recorded. If we now set the sampling frequency to 4 times the subcarrier, the number of samples during 1H will be 3rd
As shown in the figure, there are 910 samples. The effective display interval of the horizontal scanning section is assumed to be approximately 84%, and 9.142 samples are considered to be a non-recorded portion. Also, divide the 1H section into 6 blocks,
When sampling Bbit, 1 block is 128 words
(1 word = 8 bits) (!: fZ ro 7
Considering L' l-record f & wo, 2 (Feel small 7 frames) x 244 (H/fee soledo) x 6 ()b-ri/H) x 1 28 (WORD
/7'tfftsuku) = 374,784 WORD = 2
, 998,272 bits, which is approximately 3. All you need to do is put the OMbit memory in the scan converter. However, during playback, there is a memory to write the reproduced signal, a memory to store the signal for -frames, and a memory to re-output.
Approximately 3 OMbit of memory is required.

Next, a recording format for recording part of a video signal in one sector of one track will be explained using FIG. The unit of recording in one sector is UNIT.
Then, as shown in Figure 4A, the preamble and 12
It consists of a block and a postamble. As shown in Figure 4B, the block has a sink of 3 bits and an address of 12 b.
It consists of 8 sub-blocks. sink 5bi
t can be shortened and detected reliably by changing the modulation method as in 8 mm video. Also, the number of blocks is 2928 blocks considering frame recording, so
The address is 12 bits.

Sub-block has 3 bits of sink and 16 words of data.
, P parity I WORD, Q parity 1 WORD.

CRCCI WORD configuration.

Therefore, the data amount of the subblock is (19WORD+3bi
t), and the data amount of the block is sx (19W+
3b) +1sbit=1s6W+7bit, and the data amount of the unit is 12X (156'V'/+7bit)=1872W, excluding preamble and postamble.
-1-84b=15,060 bits.

If this is the case, the amount of PCM data for 8mm video is 1
Since it is approximately 1,066 times as large as 4.4 and 12 sb, sufficient recording is possible. In other words, the recording bit rate is 5.79bitμ
(368/H) to 6.18 bit/% (393/H)
Just do it.

Next, the composite video signal input from the video input terminal 7 will be explained using the electrical block diagram of FIG.
After being amplified, it is input to the A/D converter 9, where it is sampled with four times as many subcarriers as the output from the sync generator 24, and at the same time is converted into an abit digital signal. The data excluding the unrecorded portion explained in Fig. 3 is sequentially scanned by the scan converter 1
Written to memory in 0. Similarly, composite synchronization signal input terminal 22. The composite synchronization signal of the signal input from the video input terminal 7 and the carrier input from the subcarrier input terminal 23 are input to the synchronization generator 24, and the sampling frequency is four times that of the subcarrier synchronized with the input video signal. The signal is sent to scan converter 10.

Further, at the start point 4 of the vertical synchronization pulse in FIG. 2, a signal for resetting the sample salator in the scan converter is supplied from the sync generator 24 to the scan converter 1o. A non-recorded portion is determined based on the count value of this sample counter. When a no-frame signal is written to the memory in the scan converter, the scan converter 10 sends a signal to the video controller, and the scan converter 10 sends 2H worth of data, or 1636 samples, to the video controller 12. It is written into memory-11.

As shown in FIG. 4, the data written in the memory 11 is supplied to the modulation circuit 13 after parity, CRC code song, address, etc. are added thereto. Actually, the input to the modulation circuit 13 cannot be recorded in the predetermined third sector unless it is output at the timing shown in FIG.
The timing of sending to the 0j video controller 12 and the timing of outputting from the video controller 12 to the modulation circuit 13 are controlled. The scan converter 10 also has two frame memories and a video controller 12.
While the signal is being output to the other frame memory, the next signal to be recorded is stored in the other frame memory.

The H audio signal input from the audio input terminals 25, 26 is amplified by the amplifiers 27, 28, and then input to the A/D converter 29, where it is supplied from the sync generator 29 with a 180 phase shift. 2fH sample pulse,
OA where R is sampled alternately and converted to a PCM signal
The output of the /D converter 29 is sent to the audio controller 3.
2 and written into the memory 30. memory 3
For example, information during a half rotation of the cylinder is written in o. Then, when the PCM information during the next half rotation is written into the memory 31, the information in the memory 30 is read in parallel at a time regulated by the timing of the pulse generator 51 using a read clock faster than the written clock. The audio controller 32 adds an error correction code and the like, and the signal is guided to the modulator 33. The output of the modulator 13 and the output of the modulator 33 are led to the switch circuit 14 and switched by the output of the pulse generator 51, resulting in the signal shown in FIG. 6(G). The output of the switch circuit 14 is input to the adder 16 and the pilot generator 4
It is added to the output signal of 7, guided to the gate circuit 16, 18, gated by the output signal of the pulse generator 61, and becomes the recording amplifier 17, 19 as shown in FIG.
The outputs of the zero recording amplifier 17゜19 guided by SWl, S
The information is recorded on the tape by the rotary heads 20 and 21 via the R side of W2.

During reproduction, the signals reproduced by the rotary heads 20 and 21 are sent to the reproduction amplifiers 34 and 35 via the PB side of SWl, 2.
The outputs of the 0 regeneration amplifiers 34 and 35 input to the combiner 3
θ and are temporally synthesized by being switched by the output signal of the pulse generator 61, approximately as shown in FIG.
It becomes a signal. The output of the combiner 36 is separated into the PCM signal by the HPF 37 and the tracking pilot signal by the LPFsa.
The separated PCM signals are supplied to gate circuits 38 and 39. In the gate circuit 38, only data related to the video signal recorded in the third sector passes through the output of the pulse generator 61, and is guided to the demodulator 4o. The signal demodulated by the demodulator 40 is a video control a
- is supplied to the memory 12 and written to the memory 11. The signals written in the memory are sequentially read out by the video controller 12, subjected to error correction processing, and then written to one memory of the scan converter 10 according to the address attached to the data. Once data for one frame is written in the subcarrier, it is read out at a subcarrier frequency four times that of the sync generator 24. Of course, the unrecorded portion was stored in the read-only memory within the scan converter 11. By outputting a specified output, D/A converts the normal video signal into a PCM signal.
The signal is led to a converter 69 and input to an output amplifier 71 via a dropout compensator To using a 1H delay line. The output of the output amplifier 71 is output from the output terminal 72. When one memory is in a read state, the reproduced information is sequentially written into the other memory. When data for one frame is written to the other memory, the contents of the other memory are output to the D/A converter 69, and the reproduction information is sequentially rewritten to the one memory.

Next, reproduction of the audio signal will be explained. Gate circuit 39
The signal that has passed is input to the demodulator 41, demodulated, and then guided to the audio controller 32 again. The data input to the audio controller 32 is stored in the memories 30 and 31 for each data reproduced from one track.
While being written into the memory 30, the news from the memory 31 is read out, and after error correction is performed by the audio controller 32, the data is sent to the D/A converter 42.
is output to. In the D/A converter 42, when the signals are restored to the original analog signals, they become D, L, and R2CM signals, which are amplified by output amplifiers 43 and 45 and then output to output terminals 44 and 4f5.

Now, as a pilot signal for tracking during playback, a four-frequency pilot method such as that used as a tracking method for 8 mm video can be adopted.

In the 4-frequency pilot system, four frequencies f1ef2-f3*f4 in the following relationship f2-f1=f3-f4=fA f3-f2=f4-f,=tB are sequentially cyclically switched for each track. recorded.

(For 8mm video fA=fH, f13=3fH, f
H is set to be the horizontal scanning frequency of the television signal. ) Since such a pilot signal is a relatively low frequency signal in the vicinity of 100 to 200 KHz, the pilot signal recorded on the adjacent track can be reproduced as a crosstalk signal even if the head does not scan the adjacent track. can do. A pilot signal containing such a losstalk signal is obtained as an output of LPFsa. L
The output of the PF 53 is input to the balance modulation circuit 52, and is balanced modulated by the output of the pilot signal generator 47.
53 and the pilot signal generator 47 as a sum and difference signal. Circuit 64 is a tuned amplification circuit tuned to the frequency of fA, and circuit 56 is a tuned amplifier circuit tuned to the frequency of fB.
The signal of the tuning amplification circuit 54.65 tuned to the frequency of
After being rectified by the detection rectification circuits 56 and 57, it is input to the level comparison circuit 68.

The output of the level comparison circuit 58 can be used as a tracking error signal because it includes information on the amount and direction of track deviation of the head, but the information on the direction of deviation when the head 2o and the head 21 are performing reproduction is reversed. Therefore, an analog inversion circuit 59 and an electronic switch 60 are used to make the amount and direction of deviation normal. The output of the electronic switch 6o is supplied to a sample and hold circuit 61, and sampled with pulses from the pulse generator 61. This pulse is output near the center of the sector to be reproduced.

The output of the sample and hold circuit 61 is sent to a capstan control circuit via a terminal 68, the capstan motor is controlled, and tracking is maintained so that the rotary head scans over the track to be reproduced.

In the above explanation, the tracking pilot signal has been explained on the assumption that the pilot signal from the adjacent track is reproduced as crosstalk. Therefore, it is more effective to record with no gaps between tracks as shown in FIG. By reproducing with heads with different azimuths, the high frequency PCM signal has a large azimuth loss and reduces crosstalk, and the low frequency pilot signal has almost no azimuth loss, so crosstalk components from adjacent tracks can be reproduced. I can do it.

Next, the control of the cylinder motor that rotates the rotary heads 20 and 21 will be briefly explained. The signal detected by the cylinder rotation phase detector 48 (FIG. 6A) is transmitted to the amplifier 4.
9 (Fig. 6), and is supplied to a monomultivibrator 60 which adjusts the mounting error of the rotary phase detector 48, and its output is adjusted to the starting point of the first sector.

The output of the mono multivibrator 6o is sent to the phase comparator 66.
, and the output related to the vertical synchronizing signal of the sync generator 24 is the other input, and the phases of the two are compared. The output of the phase comparator 66 is supplied to the cylinder control circuit so that the cylinder rotates with a constant phase.

The output of the mono-multivibrator 6o is input as a reference signal to the pulse generator 61-, and as a result, the pulse generator 51 outputs it as a pulse related to the rotational phase of the rotary head.

The switch 63 is a switch for selecting whether to record only audio as ecH or to record both still images and audio.
The switch 62 is a select switch for selecting which sector to record or reproduce information on. The information on the 0 swing f62.63 is supplied to the system control circuit 64, which controls the pulse generator 51 according to the input information. Controls recording and reproduction sectors, one sector recording and reproduction, bare sector recording and reproduction, etc. That is, when recording is performed in the third and fourth sectors as just explained, the result is as shown in FIG. 6 (g), and the first. When recording in the second sector, the result will be as shown in Figure 6 (G), and the 6th sector will be recorded. When recording in the 6th sector, it becomes as shown in Fig. 6 (wa). In addition, when recording in sectors 1 and 2, the pulse generator 61 is used so that the same pilot signal is recorded in two sectors when recording simultaneously.
Therefore, the signal sent to the pilot generator 47 is shown in Fig. 6), and the head actually has gate circuits 16 and 18.
However, the pilot signal at the timing when the head 20 is in contact with the tape is shown in FIG. 6 (4), and the head 2
The No. 1 pilot signal is shown in FIG. 6 (r7).

Similarly, when recording in sectors 3 and 4 or sectors 5 and 6, the data is sent to the pilot generator 47 as shown in Fig. 6 (E), the head 20 is shown in Fig. 6 Φ) and the head 21 is shown in Fig. 6 (E). y) pilot signal is supplied. Of course, during reproduction, the switching signal supplied to electronic switch 60 and the signal supplied to pilot generator 47 are the same as those during recording. Also, even when recording only the audio signal, there are cases where it is recorded in the first sector and cases where it is recorded in the second sector.
Switching is done in the same way as when recording in the 6th sector. The reason why it is necessary to switch as above is because the 8mm video pattern shown in Figure 1 has been wrapped more than 180 times, and when the 180 part is divided into four or six parts, it is necessary to switch as shown above. do not have to.

It is also possible to divide the number of divisions into 8.10, but considering the condition that continuous signals can be recorded for audio signals, we have set the condition that data for one stereo field is recorded in one sector. If you think about it, the total track length can be achieved by increasing the cylinder diameter so that the recording wavelength is the same.

Furthermore, although the sampling frequency for still image recording is set to four times the subcarrier (4fsc), it is also possible to set it to 2fsc or 3fsc in order to reduce the memory capacity.

However, when sampling at 2 fsc, it is necessary to introduce intra-field sub-Nyquist sampling.

Further, during encoding, unrecorded portions are provided as shown in FIGS. 2 and 3, but it is of course possible to reduce the number of unrecorded portions.

It goes without saying that the method of configuring the recording 7-ohmant recorded in one sector of one track, especially the setting of parity pits, the method of attaching CRC codes, etc., can be changed according to various error occurrence probabilities.

Next, a second embodiment will be explained using the electrical block diagram shown in FIG.

In the embodiment shown in FIG. 1, error correction coding and the like are performed using different methods for video and audio, but in the embodiment shown in Book 2, the same method is used. In other words, as explained earlier, if you use an 8mm video PCM controller, one sector will have 54oobzt (1
osoWORD) can be recorded. That is, A/
The scan converter 10 sends data from the D converter 29 to the audio controller 32 at the same timing.
Therefore, as with the second audio signal, it is not possible to D/A convert the data of each track and return it to the original signal. Therefore, at the beginning of recording in each sector, address data is converted as shown in Figure 8. Let's add one word.

If the encoding method is the same as in the first embodiment, one frame has 374,784 '7-codes, so if it is divided into 368 tracks, the above data and address words can be recorded. In FIG. 7, the same numbers are given to the parts that perform the same operations as in FIG. 6. The composite video signal input from the video input terminal 7 is input to the amplifier 8 and then to the A/D converter 9 where it is converted into a 5-bit digital signal and then supplied to the scan converter 10. In the scan converter 10, the frequency of the subcarriers supplied from the 7-node generator 24 is sampled at four times the subcarrier frequency.
The data excluding the non-recorded portions explained in FIGS. 2 and 3 are sequentially written into the memory in the scan converter.

When the data for one frame has been written to the memory, the controller 73 sends the data 1 by adding an address word.
049 words are read out sequentially and sent during the half rotation of the cylinder. The data sent to the controller 73 is written into the memory 74. During the next half revolution, the next 1049 words of data and 1 word of address are sent to the controller 73 and written into the carrier memory 76. While being written to the memory 75, at a timing controlled by the output of the pulse generator 61,
After reading with a read clock faster than the write clock and adding an error correction code, etc., the data is supplied to the SW circuit 76 at the timing shown in FIG. Also, the signal processed in the same manner as in the first embodiment and the signal output from the audio controller 32 is supplied to the SW circuit 76.

The signals input to the SW circuit 76 are temporally synthesized by the output signal of the pulse generator 51,
supplied to The signal modulated by the modulator 8o is added to the pilot signal by the adder 15, and recorded on the tape using the same thread path as in the first embodiment. Similarly, the reproduced signal is supplied to the demodulator 77 after the pilot signal is removed by the HPF 37 in the same manner as in the first embodiment. Demodulator 7
The output of sector 7 is supplied to gate circuits 78 and 79, the output of pulse generator 61, the output of sector 3 is supplied to controller 73, and the output of sector 4 is supplied separately to audio controller 32. The information recorded in one sector of one trunk that is supplied to the controller 73 is written into the memory 74, subjected to error correction processing, and then scanned according to the address of the first word of the unit information. Written to memory within the converter. The information for each track is written alternately to memo IJ-74, 75, and while the information is being written to memory 74,
The contents of 6 are subjected to error correction processing, and scan converter 1o
sent to. Once the information for one frame is accumulated in the memory of the scan converter 1o, it is processed so as to be output to the video output terminal as in the first embodiment.

As mentioned above, if the error correction method, recording format of data recorded in one sector, etc. are made the same, it is possible to use the same controller for processing error 9 correction, etc., and when integrated into an IC, it is almost the same. It becomes possible to In addition, the same controller can be used in two different ways, which has the effect of expanding the range of uses.

Effects of the Invention As is clear from the description of the embodiments, it is possible to record a plurality of audio signals and still images associated therewith on one tape. In other words, in addition to being used as a multi-channel audio deck, it can also display images, accompanying product descriptions, and song lyrics, which has the effect of expanding its uses.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a row of patterns in the magnetic recording/reproducing apparatus of the present invention, taking 8mi+7 video as an example, FIG. 2 is a diagram showing an example of a non-recorded portion of the video signal in the present invention, and FIG. The figure shows an example of a non-recorded portion of the horizontal synchronization interval in a video signal according to the present invention, and FIG. FIG. 6 is an electrical block diagram of one embodiment of the present invention, FIG. 6 is a timing chart for supplementary explanation of FIG. 5, and FIG. 7 is a diagram showing a second embodiment of the present invention. FIG. 8 is an electrical block diagram of the embodiment, and is a configuration diagram of data input to the controller when a part of the video signal is recorded in one sector of one track in the second embodiment of the present invention. be. 9.29...A/D converter, 10...
・Scan converter, 11.30.31...
Memory, 12...Video controller, 13
, 33... Modulation circuit, 14... Switch circuit, 32... Audio controller.

Claims (4)

[Claims] (1) Magnetic tape is wound diagonally around a cylinder with a built-in rotating head, and the information signal is recorded as a group of discontinuous recording tracks.One track is divided into an even number of sectors, and two sectors are grouped as a group. 1. A magnetic recording and reproducing apparatus configured to perform recording and reproducing, wherein an audio signal is recorded in one sector of the set of sectors, and information related to the audio signal is recorded in the other sector. (2) The magnetic recording and reproducing apparatus according to claim 1, wherein the amount of data and recording format recorded in the audio recording sector and the information recording sector related to the audio signal are the same. (3) A patent claim characterized by having a switch that can be used to switch between recording only an audio signal in one sector and recording audio signals and information related to the audio signal in two sectors. A magnetic recording and reproducing device according to item 1 or 2 of the scope. (4) Four types of pilot signals are sequentially combined and recorded into recording information for each track, and when recording two sectors simultaneously, the same pilot signal is recorded in the two sectors. A magnetic recording/reproducing device according to claim 1 or 2.