JPS61104303A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To record and reproduce the combination of both of video and signals by recording a time base-compressed sound signal and a digitized and divided video signal on one plural sectors to which one track is divided. CONSTITUTION:One track corresponding to 180 deg. is divided to six sectors BL1-BL6. In case that a still picture and the sound signal are recorded on the sector BL3, they are recorded alternately on tracks, for example, still picture information is recorded on parts A1, A2... and the sound signal is recorded on parts B1, B2.... When the sound signal is recorded as a continuous signal, it is compressed to 1/12 with respect to time because the recording capacity of one sector is a signal of one frame if a cylinder is rotated with a signal having a 1/2 frequency of a vertical synchronizing signal in the video signal. The extent of 30 deg. is used as one sector consisting of 2.5 deg. preamble, 25 deg. data part, and 2.5 deg. postamble, and the stereophonic continuous sound signal is recorded.

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.

Structure of conventional example and its problems A method of dividing the recording track of a conventional helical scan type magnetic recording/reproducing device into a plurality of sectors and recording has been proposed in Japanese Patent Application Laid-Open No. 58-222402, but it has not been used for audio purposes. The only proposed use is as a tape recorder.

The use of the device is expanded by recording still image signals as well as audio signals.

Purpose of the Invention The purpose of the present invention is to divide one track into a plurality of sectors and convert information signals such as video signals and audio signals into PCM.
The purpose of this invention is to propose a system that can record and play back a combination of several types of video and audio signals on one tape.

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 as a group of discontinuous recording tracks, and divides one track into a plurality of sectors. configured to record and play back
Information for one frame of the video signal input from the video signal input terminal is stored in the scan converter, and a signal obtained by dividing the information stored in the scan converter and a signal input from the audio signal input terminal are time-selected. The axially compressed signal is alternately recorded in one sector for each trunk, and several pairs of video signals and audio signals can be recorded.

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 tape pattern diagram of the present invention, 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. Normally, video signals are recorded at positions BL1-A1 to BLe-A1o1so0.

By dividing this 180° into six equal parts, one track can be divided into six sectors. Now, of the six sectors BL1 to BLe, we will explain how to record video and audio signals in B10.0 As the video signal, of course continuous video signals cannot be recorded due to the recording band, so we will record still images. I'll decide.

FIG. 2 is an example of recording still images and audio signals in sector B10, with AI, A2. A3゜A4.・・・
Still image information, Bl, B2゜B3 is in the part called ...
, B4, . . ., audio signals are recorded alternately for each track.

Since the condition is that all audio signals be recorded as continuous signals, it is necessary to determine the recording capacity for one sector of one track, B1.

As is clear from Figure 2, if the cylinder is rotating with a signal having a frequency of % of the vertical synchronization signal in the video signal, the sound recorded in one sector will be recorded in one frame. With a signal of one meter.

be. That is, even if only the data signal is compressed on the time axis, it must be reduced to 1/12. Now, if the sampling frequency of the audio signal is 2fH (fH; horizontal synchronization signal frequency), the data amount of one sample is 5 btt, and the audio signal is stereo 20H, the data capacity is NTSC.
In the case of 526HX2Samples/HX2CH=2100W
ORD (1WORD = 8 b i ). Add 12WORD IDWORD to the above data, and make the data part 2112WORD. Figure 3 shows the format for recording in 1 sector. Recording in 1 sector The signal consists of a preamble, a data part, and a postamble.The preamble is for stabilizing self-clocking during playback, and the postamble is recorded for each sector, so taking into consideration the sector division position shift, the data Added for protection.

As shown in FIG. 2, if one sector is 30 degrees, the preamble can be set to 2.6 degrees, the data portion 250 degrees, and the postamble 2.5 degrees. The data part consists of 264 blocks, as shown in Figure 4B, including a sync signal, address signal, P, Q harrity signals, aWO
It consists of an RD data signal and a 16-bit CRCC code.

Therefore, the total amount of data to be recorded is It becomes 108 bits tX26 bits 2B512 bits.

With this configuration, it becomes possible to record continuous stereo audio signals.

Next, BLs-A1. B10-A2, B10-As.

If you want to record a still image in the area where......, you will naturally need tens or hundreds of tracks of still image signals due to storage capacity, and for that reason, the still image signals will be temporarily stored. A scan converter is required. First, the encoding method will be explained in order to determine the memory capacity in the scan converter. The vertical blanking period in the video signal is approximately 2/H (H: horizontal synchronization signal period), so as shown in Figure 4 of the inner cylinder, 1s and sH minutes are left unrecorded, and the remaining 244H of the video portion is recorded. Let's record it. If the sampling frequency is set to four times the subcarrier, the number of samples during 1H will be 910 samples as shown in FIG. The effective display section of the horizontal scanning section is considered to be approximately 84 pixels, and 142 samples are assumed to be a non-recorded portion. Also, if the 1H interval is divided into 6 blocks and the sampling is 5 btt, 1 block is 128 words, (I Word =
It will be 8 biri. Considering frame recording, 2 (field Z frame) x 244 (H/field) x 6 (lock/H) Just have it in your converter. However, during playback, there are two types of memory: one for writing the reproduced signal, and one for accumulating -frames worth of signals and repeatedly outputting them.
A set of approximately 3.0 Mbit 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.
As shown in FIG. 6A, it consists of a preamble, 22 blocks of data, and a postamble. As shown in FIG. 6B, the block has a sink of 3 bits and an address of 12 bits.

It consists of 8 sub-blocks. Sink 3bit is 8
By changing the modulation method like millivideo, short and reliable detection is possible. Also, since the number of blocks is 2928 blocks considering frame recording, the address is set to 12 bits.

The sub-block has 3 bits of sink and 16 bits of data.
RD, P parity 1 WORD, Q parity 1 WORD,
Consists of 13-bit CRCC.

Therefore, the data amount of the sub-block is (20WORD) and the data amount of the block is 8X (20WORD) + 15bit = 161W + 7
Bit and Schnitt's data amount is preamble,
Excluding the postamble, 22X (181 WORD + 7
bit) = 213490 b f t, which is equivalent to data 28512bH in which the previous audio signal is recorded in one sector.

If 20 ID blocks are added to make the number of blocks in one frame 2948 blocks, it is possible to record on 134 tracks. This means that one frame of still image can be recorded approximately every 4.6 seconds.

Next, explanation will be given using the electrical block diagram shown in FIG. The multiple composite video signals input to the video input terminal 7 are input to the amplifier 8, and after being amplified, are input to the A/D converter 9, which is a subcarrier of four times the output of the sync generator 24/pulling. At the same time, it is converted into 8-bit digital data. The output of the A/D converter 9 is input to the scan converter 10, and the data excluding the unrecorded portion explained in FIGS. 4 and 6 is sequentially stored in the memory 7.
It is written in 3. Similarly, the composite synchronization signal and subcarrier of the signal input from the video input terminal 7, which is input from the composite synchronization signal input terminal 22 and the subcarrier input terminal 23, is input to the sync generator 24, and the subcarrier synchronized with the input video signal is input to the sync generator 24. A signal with a sampling frequency four times that of the carrier is supplied to the A/D converter 9 and scan converter 1o described above. Further, at the start point of 3H of the vertical synchronization pulse in FIG. 4, a signal for resetting the sample counter in the scan converter is supplied from the sync generator 24 to the scan converter. The count value of this sample counter is counted up by the sample pulse, and the input data is sequentially written to the memo IJ-73 while determining the unrecorded portion based on this count value.・Data for memory 731CI frames is written. Then, a signal is sent to the scan converter 10 and the video controller 12, and from the memory 73, data for 1 UNIT (22 blocks) explained in FIG. 6 is sent to the video controller 12 via the scan converter 10. and written to temporary memory-11. While the data for one sector of one track is being sequentially sent to the video controller 12 in this way, the next still image signal is written to the memory 74 in the same manner.

In this way, the memory 73 and 74 are configured to be written alternately. As shown in FIG. 6, the data written in the memory 11 is supplied with a parity, a CRC code, a sync, an address, etc., and then supplied to the modulation circuit 13. In reality, the input to the modulation circuit 13 is the eighth
If it is not output at the timing shown in the figure (f), it will not be possible to record in the predetermined third sector, so the output of the pulse generator 51 is sent from the scan converter 10 to the video controller 12 at the timing, and from the video controller 12 to the modulation circuit 13. Timing is controlled.

That is, to explain using FIG. 8(S), t2 is the timing at which data is sent from the video controller 12 to the modulator 13, t3 is a pause period, and t4 is the timing at which data is transferred from the scan converter 1o to the video controller 12. , t5 is the processing time for adding the parity and CRC code described above, and t6 is a pause period for waiting for the start signal of t2.

The audio signals input from the audio input terminals 25 and 26 and the high level are amplified by amplifiers 27 and 28 and then input to the A/D converter 29. In the A/D converter 29, the 2fH sample pulses with a phase shift of 1000 supplied from the sync generator 29 are alternately sampled and converted into an 8-bit digital signal. The output of the A/D converter 29 is input to the audio controller 32 and then written to the memory 30.

The memory 30 stores information during one revolution of the cylinder.
written. Then, in parallel with the information during the next revolution being written into the memory 31, the information in the memory 30 is read out at a time regulated by the timing of the pulse generator 51 using a read clock faster than the written clock. , an error correction code etc. are added by the audio controller 32, and the signal is guided to the modulator 33. That is, as shown in FIG. 8 (g), the signal for each -rotation is M
l.

30, the data are alternately written into the memory M231 and subjected to error correction code processing in time tl, and then output to the modulator 33 at the shaded area in FIG. 8(G). Output of modulator 13 (
8) is input to the adder 15, added to the output signal of the pilot generator 47, and then added to the gate circuit 16.
, is gated by the output signal of the pulse generator 51 , and is guided to the recording amplifier 17 . The output of the recording amplifier 17 is recorded on the tape by the rotary head 2o via the R side of SWl. Similarly, the output of the modulator 33 (FIG. 8G) is input to the adder 14, where it is added to the output signal of the pilot generator 47, guided to the gate circuit 18, gated with the output signal of the pulse generator 51, and then sent to the recording amplifier. Guided by 19. The output of the recording amplifier 19 is recorded on the tape by the rotary head 21 via the SW2. SW
Of course, SW1 and SW2 are connected to R1111I only when the head is running through the sector to be recorded.0 During playback, the signals reproduced by the rotating head 20 and 21 are connected to SW1 and SW2. through the PB side of the regenerative amplifier 34.35
is input. Regenerative amplifier 34°350 output is synthesizer 3
6, are switched by the output signal of the pulse generator 51, and are temporally synthesized, resulting in the signal approximately shown in FIG. 8 (E). The output of the combiner 36 is separated into a PCM signal by an HPF 37 and a tracking pilot signal by an LPFsa. The PCM signal separated by the HPF 37 is sent to gate circuits 38 and 39.
supplied to In the gate circuit 38, only data related to the video signal recorded in the third sector (No. 8 in FIG. 8) is passed by the output of the pulse generator 61, and
It leads to 0. The signal demodulated by the demodulator 40 is supplied to the video controller 12 and written to the carrier memory 11. The signals written in the memory 11 are sequentially read out by the video controller 12, subjected to error correction processing, and then written to one memory 73 of the scan converter 10 according to the address attached to the data. Once data for one frame is written in one memory 73 of the scan converter, it is read out at a frequency of the carrier four times that of the sync generator 24.

Of course, for unrecorded parts, scan converter 1
By outputting a specified output stored in the read-only memory in the 1H, the PCM signal of the normal video signal is led to the D/A converter 69, and the dropout compensator 70 uses a 1H delay line. The signal is input to the output amplifier 71 via. The output of the output amplifier 71 is output from the output terminal 72. When one memory 73 is in a read state, the reproduced information is sequentially written into the other memory 74. When data for one frame is written to the other memory 74, the other memory 74
The contents of 4 are output to the D/A converter 69. While the contents of the memory 74 are being output to the D/A converter 69,
The reproduction information is sequentially written into the memory 7:]. To add some details using the timing chart of FIG. 8, the signal shown in FIG. 8 0) is output from the demodulator 40. video con)
.

- In La 12, after the data is input at the diagonally shaded timing (/→), the error is corrected at t8 based on the margin time at t7, and the information is transferred to the scan converter 1o at t9. and tl. is the time for waiting for the next data.

Next, reproduction of the audio signal will be explained. Gate circuit 39
Figure 8 (3) is a signal obtained by compressing the time axis of the audio signal that has passed through the
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 alternately written to memo +7-30.31 for each data played from one track, and while the data is being written to the memory 30, the information in the memory 31 is being read. After being error-corrected by the audio controller 32, it is output to the D/A converter 42. In the D/A converter 42, it is restored to the original analog signal and becomes L and R2CH signals, which are amplified by an output amplifier 43.45 and then output to an output terminal 44.46.

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

The 4-frequency pilot system uses four frequencies f1. f2. f3. f4 is sequentially cyclically switched and recorded for each track. (
For 8mm video, fA=fH, fB=3fH.

fH is set to be the horizontal scanning frequency of the television signal. ) Such a pilot signal is 1oo~200Kl-1
Since the signal has a relatively low frequency near z, the pilot signal recorded on the adjacent trunk can be reproduced as a crosstalk signal without the head scanning the adjacent track. The pilot signal, which does not include the losstalk signal, is obtained as the output of the LPF 53. The output of the LPF 53 is input to the balanced modulation circuit 52, balanced modulated by the output of the pilot signal generator 47, and the LPF
53 and the pilot signal generator 47 as a sum and difference signal. The circuit 64 is fp,
The circuit 56 is a tuned amplifier circuit tuned to the frequency of f.
This is a tuned amplifier circuit tuned to the frequency of B. The signals from the tuned amplifier circuits 64 and 55 are input to the level comparison circuit 68 after being rectified by the detection rectification circuits 56 and 57. The output of the level comparison circuit 68 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 reproduction is performed by the head 2o and head 21 is reversed. Therefore, analog reversal rotation 6
9 and electronic switch 6o to make the amount of deviation and direction of deviation normal. The output of the electronic switch 60 is supplied to a sample and hold circuit 61 and sampled with pulses from the pulse generator 51. This pulse is output near the center of the sector to be reproduced. The output of this sample and hold circuit 61 is sent to the capstan control circuit via terminal θ8, 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. 8A) is sent to the amplifier 4.
9 (Fig. 8), and is supplied to a mono-multivibrator 6o which adjusts the installation error of the rotary phase detector 4, and its output is adjusted to the starting point of the first sector.

The output of the mono multivibrator 50 is sent to a phase comparator 66.
, and the output related to the vertical synchronization signal of the sync generator 24 becomes the other input, and the phases of the two are compared. The output of the phase comparator 66 is fed to the cylinder 1 cedar control circuit, so that the cylinder rotates at a constant phase. The output of the mono-multivibrator 6o is input as a reference signal to the pulse generator 51, and as a result, the pulse generator 61 outputs a pulse related to the rotational phase of the rotary head.

The switch 62 is a select switch for selecting which sector to record or reproduce data.

The information of the switch 62 is supplied to the system control circuit 64, and the system control circuit 64 controls the pulse generator 51 according to the input information.
Controls recording and playback sectors. That is, as explained above, when recording in the third sector, a recording current flows in each sector as shown in Figure 8 (e), and when recording in the first sector, the recording current flows in the second sector. When recording, the pulse generator 51 is set so that the recording current flows like a chopstick when recording in the 6th sector.
is controlled.

Further, although the number of divisions is set to 6, it is also possible to set the number of divisions to 2 to 5 or more. Regarding the audio signal, on the condition that it is possible to record a continuous signal, that is, on the condition that the time information of one stereo frame can be recorded in one sector, the cylinder is set so that the recording wavelength is the recordable length. Of course, it is only necessary to set the diameter.

Furthermore, although the sampling frequency for still image recording is set to four times the subcarrier (4fso), it is also possible to set the sampling frequency to 2fsc + 3fsc in order to reduce the memory capacity. Also, when encoding, Figures 4 and 5
Although the non-recorded portion is provided as shown in the figure, it is of course possible to make it even smaller. In addition, the method of configuring the recording format for recording in one sector, especially the setting of parity pits, the method of attaching CRC codes, etc., was explained using Figures 3 and 6, but it goes without saying that the settings can be made in a balanced manner. It is.

Furthermore, although this embodiment has been explained by recording still images, it is of course possible to record information related to audio signals, such as information for turning on various lamps that match the audio, instead of still images. .

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 image information related thereto on one tape. By doing so, it has the effect of expanding various uses, such as displaying song lyrics, product descriptions with catalogs, and recording images to enhance the image when opening audio.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an example of a tape pattern in the magnetic recording/reproducing apparatus of the present invention, FIG. 2 is a diagram showing an example of a tape pattern when a still image and an audio signal are recorded in the BL3 portion of FIG. 1, FIG. 3 is a diagram showing an example of a recording format when an audio signal is recorded in one sector of one track, and FIG. 4 is an example of an unrecorded portion of a vertical synchronization signal portion in a video signal according to the present invention. FIG. 5 is a diagram showing an example of a non-recorded portion of the horizontal synchronization section in a video signal according to the present invention, and FIG. 6 is a diagram showing a part of the video signal recorded in one sector of one track. FIG. 7 is an electrical block diagram of an embodiment of the present invention, and FIG. 8 is a timing chart for supplementary explanation of FIG. 7. 9.29...A/D converter, 10...
...Scan converter, 11.30.31...
・Memory, 12...Video controller, 13
, 33...Modulation circuit, 16.18...
Gate circuit, 32...Audio controller.

Claims (2)

[Claims] (1) A magnetic tape is wound diagonally around a cylinder with a built-in rotary head, and information signals are recorded and reproduced as a group of discontinuous recording tracks, and each track is divided into a plurality of sectors, A magnetic recording/reproducing device characterized in that a signal obtained by compressing the time axis of an audio signal and a signal obtained by digitizing and dividing a video signal are recorded in one sector. (2) The magnetic recording and reproducing apparatus according to claim 1, wherein audio signals and video signals are alternately recorded on each track.