JPS6049986B2 - signal transmission equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for transmitting a plurality of continuous signals even when using a transmission means such as a VTR, which periodically generates discontinuous portions of the signal during signal transmission and is prone to time axis fluctuations. The object of the present invention is to provide a device that can multiplex data effectively and transmit data without time axis fluctuation.

When trying to multiplex and transmit many types of signals, especially when recording and transmitting them, it is effective to use a magnetic tape recording/reproducing device (hereinafter referred to as VTR) because of its large recording capacity, but currently Since the VTRs used must serially multiplex and record signals, it is difficult to rewrite only the contents of a certain channel or to record each channel separately instead of simultaneously. It was inconvenient. Furthermore, in TR, there is a problem in that during recording and reproduction, time axis fluctuations such as rows and flutters occur, making it difficult to reproduce correct signals. This kind of inconvenience is the same in almost all multiplex transmission devices other than VTRs.

Therefore, the present invention has been developed to enable transmission when recording each channel individually and independently in a device such as a VTR that multiplexes and transmits signals of many channels in a serial format, and to transmit the signals without time axis fluctuation. The purpose is to make it possible.

Another object of the present invention is to provide a device that is particularly effective when using TR. For this reason, the present invention divides a plurality of types of signals to be transmitted into blocks at equal intervals in time, and compresses each block in time.
and compression multiplexing means for temporally serially multiplexing the plurality of compressed signals with blanking portions for each, and a characteristic of periodically generating discontinuous portions of the signal. A transmission means for transmitting the output compressed signal by superimposing one of the blanking periods and this discontinuous portion, and separating the multiplexed compressed signal output from this transmission means, and separating the multiplexed compressed signal from the compressed signal. The above-mentioned compressed signal is read using the extracted self-clock, and the above-mentioned compressed signal is expanded in time using a reference clock of a constant frequency, and the expanded signals are serially arranged for each type to generate a plurality of signals. Re-signal type. The invention is characterized in that it is equipped with a separating and elongating means for producing a desired result.

Further, it is characterized in that a magnetic recording/reproducing device is also applied as a transmission means. DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below with reference to the drawings showing one embodiment thereof.

1 and 2 are time charts for explaining the transmission method in this apparatus, and in this embodiment, a case will be explained in which four types of continuous signals are multiplexed and transmitted.

The upper part of Figure 1A shows the second
Figures A'' to E'' are time charts for reading and reproducing, and the signals are represented by solid lines in the figures. First, in FIG. 1, A-D represents four types of signals A-D to be recorded or transmitted, and blocks Al, A, . . .
,BI,B■,...,CI,C■,...,DI,D■,
Divide into... If these signals A to D are multiplexed, recorded, and transmitted as they are, the above-mentioned problem will occur, so in this device, each block AI,
... to approximately 113 in time and AI,
an,..., Bl, b■, ..., CI, c■,...
DI, d■, and these compressed signal frames for each block are Ai, bi, ci, di (where i=I,
,... are rearranged in the order shown in E. In this way, a blanking portion where no signal exists can be created between each compressed signal. When reproducing each signal, it is sufficient to perform the completely opposite operation to the recording and transmitting operation in which 7-hour compression is performed as shown in Fig. 1. In other words, the read serial compressed signals Ai'', Bi'' ，
For the playback output E'' of Ci'', Di''..., each compressed signal Aj, bi, ci, dj... is taken out block by block and expanded temporally at a ratio opposite to that at the time of compression. , by serially arranging the original four types of signals A-D.
Continuous signals A″ to D″ are obtained by reproducing the . Also,
When reading out the compressed signals Ai, bi, ci, and di, the read compressed signals are once read into the decompression means using a self-clock created from the compressed signals, and then the time is read out from the decompression means using a reference clock of a constant frequency. By reading out the data while expanding it and arranging it serially, a signal with no time axis fluctuation can be reproduced.

Therefore, according to such a transmission method, it is possible to change the transmission channels of many types of signals, for example, by exchanging only the contents of a certain channel among the recording channels, or by recording each channel separately instead of transmitting them at the same time. There are some devices that can be used for transmission.

That is, the signals A to D of each channel are divided into blocks, and each block is compressed in time and arranged serially in time, and the signals are recorded or transmitted. Since there is a blanking part with no signal between each block of the compressed signal, even if there is some time axis fluctuation in the transmission means such as a recording/reproducing device, the fluctuation will be contained within the blanking part. It is possible to easily record and transmit compressed signals without causing any overlap, and to transmit each compressed signal by individually recording or reading out the compressed signals. Furthermore, by using a self-clock, it is possible to reproduce a good signal without time axis fluctuation.

Next, an embodiment of an apparatus for specifically implementing such a recording method will be described with reference to FIGS. 2 and 3. Here 1-4
are the respective input terminals of the four types of signals A to D to be recorded, 5 to 1
2 respectively connect the signal A-DJ to blocks Ai, Bi, Ci.
, Di, and shift registers 13 to 20 are for dividing and temporally compressing the reproduced signals Ai, bi, ci, respectively.
, di in time and return them to the original signals A, B, C, and D; 21 is an electronic switch that sequentially extracts and rearranges the compressed signals; 22 is for transmission of records, etc. 23 is a write amplifier, 24 is a transmission means, in this embodiment a magnetic recording/reproducing device, 25 is a read amplifier, 26 is a code converter for reproduction, 27 is a self-clock regenerator, and 28 is a reference. Coolock generator, 29,3
0 is a control signal generator, 31 is a synchronizing signal adder, 32 is a synchronizing signal regenerator, and 33 to 36 are output terminals for each of four types of signals. In addition, terminal a is a common write clock output terminal for shift registers 5 to 8, and terminal b is a common write clock output terminal for shift registers 5 to 8.
Terminal cmf is an output terminal for a shift/load signal used to transfer the outputs of 8 to shift registers 9 to 12, respectively; terminal cmf is an output terminal for a read clock for shift registers 9 to 12;
Terminal q is an output terminal for a signal for switching the electronic switch 21. Signals A to D input from input terminals 1 to 4 are simultaneously written to shift registers 5 to 8 in units of blocks Ai, Bj, Ci, and Di, respectively.

As shown in FIG. 1E, since the signal E during recording has a blanking portion where no signal exists, the signals Ai-Di written to the shift registers 5 to 8 during that period are transferred to the shift registers 9 to 12. and shift register 9~
12 and sequentially. Here, shift register 5
By setting the frequency of the read clocks of shift registers 9 to 12 higher than the write lock of 8 to 8, the output of the electronic switch 21 is temporally controlled in block units as shown in FIG. 1E. Each compressed signal Ai, bi,
ci and di are obtained in an arrayed form. A synchronizing signal adder 31 adds a synchronizing signal to the output signal of the switch 21 to provide a time reference for the recording/reproducing section 24 , and a code converter 22 generates a self-clock at the time of reading, thereby providing a time reference for the recording/reproducing section 24 . It is converted into a signal that can compensate for shaft fluctuations. For example, when the signal bit of the binary digital signal E to be recorded changes from "゜0゛" to "1" (or when it changes from "1" to "0", but only when one of the changes occurs). , so-called FM conversion is performed in which the signal level is inverted at each bit boundary.
If such conversion is performed, the self-clock regenerator 27 can generate a clock for the read signal when reading the signal from the recording/reproducing section 24, and by using this self-clock, the recording/reproducing section 24 can eliminate jitter, etc. Each bit of the recorded signal can be read correctly even if there is a time axis fluctuation. However, even in that case, it goes without saying that the signal itself extracted by the self-clock includes time axis fluctuations. On the other hand, a signal necessary for this code conversion, such as a clock, is generated at terminal 1 of the control signal generating section 29. The output of the code converter 22 is sent to the write amplifier 23
The data is recorded in the recording/reproducing device 24 through the. The recording/reproducing section 24 has a structure similar to, for example, a normal two-head helical scan type VTR, and is composed of a tape, a head, a device for driving them, and a circuit for controlling them. A reference signal for controlling the drive of the tape and head of the recording/reproducing device 24 is generated at the terminal j of the control signal generating section 24. The compressed signal read out from the recording and reproducing device 24 is amplified by the readout amplifier 25, and this compressed signal is converted by the code converter 26 and converted by the code converter 22.
The compressed signal E'' is restored in the same manner as before.

At the same time, from this compressed signal E'', the self-clock regenerator 2
7, the self clock is regenerated, and this self clock, the output of the synchronization signal regenerator 32, and the reference clock generator 2
From the reference clock of 8, the control signal generating section 30 generates the control signals necessary to obtain the original continuous signals A-D. The self-clock regenerator 27 generates a PLL from the regenerated signal.
(Phase - 10cked upper 00p), or in the case of recording and reproducing using the self-clock method as described above, the self clock is taken out to obtain the clock for reading, and this clock is the reproduced compressed signal E''
It changes over time in exactly the same way. Therefore, by using this clock as the write clock for the shift registers 13 to 16, signals can be read without error. Code converter 26 and self-clock regenerator 27
A specific example of this is shown in FIG. Here, waveform shaping circuit 3
7 to shape the waveform into the correct pulse shape, a differentiator circuit 38 to differentiate its output, and a bridge circuit 39 to invert the negative pulse in the positive direction to generate a pulse at each rising and falling edge of the compressed signal. get. Next, this pulse triggers the monostable multi 40 as the self-clock regenerator 27 to obtain a self-clock having a width of about 314 bits, which is one bit width of the compressed signal. Using this self-clock, the gate 41 gates the output of the bridge circuit 39, and the output triggers the monostable multi 42 to obtain a compressed signal output with a width of 1 bit. Note that the terminal k-n of the control signal generator 30
are output terminals of respective write clocks for shift registers 13 to 16, terminal 0 is an output terminal of a shift load signal for transferring the signals written to shift registers 13 to 16 to shift registers 17 to 20, and terminal p is This is a common read clock output terminal for reading signals from shift registers 17-20.

The output E'' of the code converter 26 is sent to the shift registers 13 to 1.
6, and during the blanking portion where no signals are included, the signals in shift registers 13 to 16 are shifted ◆Shifted by the load signal. The data are transferred to registers 17-20 and read out. While the signals of shift registers 17 to 20 are being read, the next signal is being read out from shift register 1.
3 to 16 are written. The read clocks of shift registers 17-20 have the same frequency ζ as the signals appearing on terminals 1-4.
Since the clock is a clock of A″~D″ can be obtained o
FIG. 3 is a time chart of signals generated from the control signal generators 29 and 30. Here, continuous signal A- input from terminals 1 to 4
D is a recording control unit signal generated from the control signal regeneration circuit 29, a is a write clock output from terminal a to commonly write signals A to D to shift registers 5 to 8, and b is a signal from shift registers 5 to 8. A shift/load signal, cmf, is generated from terminal b in order to transfer one block of signals AI, . . . written to shift registers 8 to shift registers 9 to 12, respectively.
is a read clock outputted from the terminal cmf in order to temporally compress and read out the signals written in the shift registers 9 to 12. The output of the electronic switch 21, that is, the temporally compressed and rearranged recording signal Ai-D
It is i. Further, k-0 is a reproduction control signal generated from the control signal generator 30, and k-n is a signal from the shift register 13 to
Write signals for shift registers 13 to 16 generated from terminals k and n, respectively, are used to individually write compressed signals Ai and Di of each block from the output signal of the code converter 26, ie, a signal such as E'' to 16. It's a clock.o
converts the signals of the shift registers 13 to 16 to the code converter 26
This is a shift/load signal generated from terminal 0 to transfer the signals to shift registers 17 to 20 during the blanking portion where there is no signal in the output signal of shift register 17 to 20. Each shift register 17 is used to expand the signal to the same length as the signal A-D and read it out.
.about.20 is a common read clock generated from the terminal p. A''-D'' are continuous output signals appearing at output terminals 33-36. As described above, according to the present invention, in a device that serially multiplexes signals of a large number of channels, records them, etc., and transmits the signals, each channel can be recorded and transmitted independently. Of course, stereo recording and playback is also possible by simultaneously recording and transmitting each channel. In addition, when signals are recorded and reproduced using a rotating head such as that currently used in VTRs, if discontinuous parts due to head switching become a problem, or if discontinuous parts occur periodically for some other reason. Even if these discontinuous parts become a problem in a transmission system where it is unavoidable that these discontinuous parts occur, it is sufficient to ensure that such discontinuous parts are contained within the blanking period of the compressed signal E. If a device such as the one according to the present invention is also used in the device, it will be possible to multiplex record many kinds of signals.
For example, when using a two-head helical scan type VTR, the head switches every period corresponding to one field of the TV image, so if this switching period is The division period of each block into which is divided is set to the period of V, and the signal is temporally compressed for each block.

Furthermore, in the device of the embodiment described above, the input terminals 1 to 1
By using the output obtained by A/D converting the audio signal as the input signal supplied to the output terminals 4 and connecting a D/A conversion circuit to reconvert the playback output after the output terminals 33 to 36, high quality of the audio signal can be achieved. recording and playback becomes possible.

Furthermore, if the shift registers 13 to 16 are written using the output clock of the clock regenerator 27, and the shift registers 17 to 20 are read using the reference clock of the reference clock generator 28, the wah in the output signal can be reduced.・Flutter can be completely removed. That is, when recording in the recording/reproducing device 24, the compressed signals Ai to Di read out from the shift registers 9 to 12 are arranged in sequence, creating a blanking area where no signals are included, and the switching position of the VTR head is set at the center of the blanking area. This is because even if the readout signal from the recording/reproducing device 24 fluctuates somewhat over time, discontinuous portions due to head switching can be prevented from overlapping with the compressed signal. Furthermore, in the device of the above embodiment, shift registers 5 to 12, 1
3 to 20 are used, but since they all have the same capacity, it is also possible to use the 5 to 12 set and the 13 to 20 set, and in that case, the capacity of the shift register used is halved. can be reduced to In addition, these shift registers are configured with elements capable of storing analog quantities such as BBD, and the code converter 22 is configured with an analog modulator such as FM.
Of course, if each of the code converters 26 is configured with an analog demodulator such as FM, it becomes possible to record and reproduce many types of continuous signals in the form of analog signals. As described in detail above, according to the present invention, even when using a transmission device such as a facsimile transmission device or a magnetic disk device that has characteristics that periodically cause discontinuous portions of the signal, each block obtained by dividing a plurality of signals can be used. The compressed multiplexed signal is compressed and multiplexed with a blanking period when serially multiplexed in time. Since the signals are superimposed and transmitted, a plurality of continuous signals can be multiplexed and transmitted even though there are discontinuous portions of the signals.

In addition, especially in general VTRs, by overlapping the head switching period with the blanking period of the compressed multiplexed signal, multiple continuous signals can be recorded well, making effective use of its wide band recording characteristics. It is possible to record with high efficiency or high quality. Furthermore, even if there is a time axis variation such as wow or flutter in the transmission means and TR, it is possible to compensate for this and transmit and reproduce a signal without time axis variation.

[Brief explanation of the drawing]

Figure 1 A9B9C9D9E9N9B'9C'9D'', E
" is a chart for explaining the principle of a continuous signal transmission/transmission device in an embodiment of the present invention, FIG. 2 is a block diagram of the same device, and FIG. 3 is X, Y, X'', A9b9c9d9e9f.
9k9l9m909p is a waveform diagram for explaining the operation of the same device, and FIG. 4 is a concrete clock diagram of the self-clock regenerator used in the same device. 1-4...Input terminal, 5-20...Shift register, 21...Electronic switch, 24...
. . . Recording/reproducing device, 27 . . . Self-clock regenerator, 28 . . Reference clock generator, 29, 30.
...Control signal generator 5, 33 to 36...
Signal output terminal.

Claims (1)

[Claims] 1. A plurality of types of signals to be transmitted are divided into blocks at equal intervals in time, each block is compressed in time, and the compressed plurality of types of signals are each divided into blanking portions. It has a compression multiplexing means for serially multiplexing in time with intervals, and a characteristic of periodically producing discontinuous portions of the signal, and the compressed signal output from the compression multiplexing means is multiplexed in the blanking period. A transmission means for superimposing and transmitting one of the discontinuous portions and the discontinuous portion, and separating the multiplexed compressed signal outputted from this transmission means, and converting the compressed signal using a self-clock extracted from this compressed signal. The compressed signal is written in the memory means, and the compressed signal is temporally expanded using a reference clock having a constant frequency, and then read out from the memory means, and the expanded signals are serially arranged for each type to generate the plurality of types of signals. A signal transmission device comprising: separation and expansion means for regenerating. 2. Divide the multiple types of signals to be recorded into blocks at equal intervals in time, compress each block in time, and divide the compressed multiple types of signals in time with blanking portions in between. Compression multiplexing means for serially multiplexing and periodic head switching periods of the magnetic head are generated, and the compressed signal output from the compression multiplexing means is superimposed on one of the blanking periods and the head switching period. a magnetic recording and reproducing device for recording and reproducing information; a multiplexed compressed signal outputted from the magnetic recording and reproducing device; and writing the compressed signal into a memory means using a self clock extracted from the compressed signal; Separating and expanding means for temporally expanding and reading out the compressed signal from the memory means using a reference clock of a constant frequency, and serially arranging the expanded signals for each type to reproduce the plurality of types of signals. A signal transmission device comprising: