JPH02166677A - Digital magnetic recording and reproducing system - Google Patents

Abstract

PURPOSE:To record and reproduce plural signals by the same device by providing the number of recording and reproducing channels to record the signals of highest recording bit rate out of plural kinds of recording signals, and selecting the required number of recording and reproducing channels corresponding to the recording bit rate of individual signal. CONSTITUTION:Recording and reproducing circuits equivalent to the number of channels required for the recording of the signal with the highest recording bit rate out of the plural recording signals, magnetic heads 301-308, and a rotary cylinder 331, etc., are provided. And the required number of recording and reproducing channels is selected by a switching the magnetic heads 301-308 and the channel of a circuit, etc., corresponding to the recording bit rate of individual recording signal, and the recording and reproducing are performed. In such a way, it is possible to perform the recording and reproducing of the plural signals by the same device.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for recording and reproducing a plurality of video signals having different recording bit rates using the same device in a multi-channel digital magnetic recording and reproducing device.

2. Description of the Related Art As a video signal recording and reproducing device, a system related to a so-called digital VTR, which is a device that digitally processes a video signal and directly records and reproduces the digital data on a magnetic tape, has been studied and has begun to be put into practical use in recent years.

Hereinafter, a conventional example of a digital VTR will be explained based on the drawings. FIG. 3 is a block diagram of the first conventional example.
It represents an example of an NTSC composite digital VTR (hereinafter referred to as "D2-VTR") whose standard was established by CIR (International Consultative Committee on Radio Communications). 10
4 is an input terminal, 114 is an output terminal, 122 is an A/D converter, 132 is a D/A converter, 179 is an encoder, 181 is a decoder, 209.210 is a modulator, 229.230 is a demodulator, 249.250 is a recording amplifier, 269.270 is a playback amplifier, 373.374 is a switch, 317-32
0 is a magnetic head, 333 is a rotating cylinder, and 343 is a magnetic tape.

An NTSC composite signal is applied to input terminal 104 and the A/D converter! 22, it is converted into a digital signal.

The output of A/D conversion 1122 is applied to encoder 179;
A predetermined encoding process is performed and the signal is divided into two channels. The two-channel output of the encoder 179 is applied to modulators 209 and 210, digitally modulated by a Miller square code, and then applied to recording amplifiers 249 and 250. to magnetism,
One set of throats 317.318, magnetic head 319.320
As another set, the two sets of magnetic heads are arranged at positions 1806 on the rotating cylinder 333, and the magnetic tape 343 is wound around the rotating cylinder 333 by 180'', and one set of two heads covers two channels. Signal processing is performed. Also, the diameter of the rotating cylinder 333 is 98.4 m.
m1 rotation speed is 5400 rpm. During recording, switches 373 and 374 are closed to the recording side;
3.374 and magnetic heads 317 to 320, two channels of information are recorded on the magnetic tape 343. The recording bit rate at this time was 127 Mbps, the recording bit rate per channel was approximately 84 M bps, the track pitch was 39 μm1, and the shortest recording wavelength was 0.
It is 854 μm.

On the other hand, during playback, the switches 373 and 374 are closed to the playback side, and the two-channel information recorded on the magnetic tape 343 is transferred to the magnetic heads 317 to 320 and the switch 374.
3.374 to the reproduction amplifier 289.270. The two-channel output of the reproducing amplifier 289.270 is applied to the demodulator 229.230 and digitally decoded. The two channel outputs of the demodulators 229 and 230 are sent to the decoder 18.
A predetermined decoding process is performed. Decoder 1
The output of 81 is applied to the D/A converter 132, and the output of the original NT
It is converted into an SC composite signal and output via the output terminal 114.

Moreover, FIG. 4 is a block diagram of the second conventional example, in which CCIH
105 to 107 are input terminals, 115
-117 are output terminals, 123-125 are A/D converters,
133 to 135 are D/A converters, 180 is an encoder, 18
2 is a decoder, 211 to 214 are modulators, 231 to 234
is a demodulator, 251 to 254 are recording amplifiers, 271 to 27
4 is a reproduction amplifier, 375-378 are switches, 321-
324 is a magnetic head, 334 is a rotating cylinder, and 344 is a magnetic tape.

A luminance signal and two color difference signals are applied to input terminals 105-107 and converted into digital signals by A/D converters 123-125. The outputs of the A/D converters 123 to 125 are applied to an encoder 180, subjected to a predetermined encoding process after multiplexing, and divided into four channels. encoder 180
The four-channel outputs of are applied to modulators 211 to 214,
After being digitally modulated using a scrambled NRZ code, the signal is applied to recording amplifiers 251 to 254. The magnetic tape 344 is wound about 250' around the rotating cylinder 334, and four channels of signal processing are performed by a set of four magnetic heads 321 to 324. Also, the diameter of the rotating cylinder 334 is 75 mm, and the rotation speed is 9000 rpm.
It is m. During recording, the switches 375 to 378 are closed to the recording side, and the switches 375 to 378 and the magnetic head 32
Four channels of information are recorded on the magnetic tape 344 via channels 1 to 324. The recording bit rate at this time was 227
Mbps, the recording bit rate per channel is approximately 57 Mbps, and the track pitch is 40 μm1.
The shortest recording wavelength is 0. It is 9 μm.

On the other hand, during playback, the switches 375 to 378 are closed to the playback side, and the four channels of information recorded on the magnetic tape 344 are transferred to the magnetic heads 321 to 324 and the switch 378.
5 to 378 to reproduction amplifiers 271 to 274. The four-channel outputs of the reproducing amplifiers 271-274 are applied to demodulators 231-234 and digitally decoded. The 4 channel outputs of the demodulators 231 to 234 are sent to the decoder 18.
2, and undergoes predetermined decoding processing to become digital signals of a luminance signal and two color difference signals. The output of the decoder 182 is applied to D/A converters 133 to 135, where it is converted into an original luminance signal and two color difference signals, and output from output terminals 115 to 135.
117.

Problems to be Solved by the Invention In the conventional examples described above, the bit rates of data to be recorded and reproduced are 127 Mbps and 227 Mbps, respectively! =
The D2-VTR and D1-VTR have different signal processing circuits and recording/reproducing mechanisms. That is, D2-
VTRs and Dl-VTRs differ in terms of modulators, demodulators, recording amplifiers, playback amplifiers, diameters of rotating cylinders, and tape winding angles. This is because the diameter of the rotating cylinder, the number of rotations of the rotating cylinder, and the corners of the magnetic tape were selected in order to minimize the number of magnetic heads in each VTR for recording and reproducing.
When recording and reproducing a composite signal and a 4:2:2 component signal, the recording and reproducing mechanism and circuit cannot be shared. That is, it is difficult to record and reproduce two signals with different recording bit rates on the same magnetic recording and reproducing device.

The present invention eliminates the above-mentioned drawbacks, and when recording and reproducing a plurality of signals with different recording bit rates, it is possible to share a recording and reproducing circuit and a mechanism, and it is possible to record and reproduce a plurality of signals with the same magnetic recording and reproducing device. This paper proposes a method to make this possible.

Means for Solving the Problems In the present invention, a plurality of signals At, A2.・・・・・・
+An is input, the recording signal Bl is input.

B2. . . , Bm, and record the recording signal B1. B2.・・・＋B
m with the number of channels Nl, N2 .・
..., divided into Nm recording and reproducing channels.

Recording signal B1. B2. ..., B111
Let the recording bit rates of R1, R2, . . .
・If +Rm, recording bit rate) R1, R2,...
..., Rm, R1≦R2≦...≦Rm (1)
shall be. Further, the maximum recording bit rate per channel is set as r, and the relationship between the recording bit rate, the number of channels, and the maximum recording bit rate per channel is Nto1/rS Nl (1:1. 2...., m) Set so that the relationship (2) holds.

As described above, by setting the number of recording and reproducing channels, the number of revolutions of the rotary cylinder is kept constant and the recording bit rate per channel is set almost constant. can be set in the same way even if the bit rate of the recording signal is different, and the recording/reproducing circuit and magnetic head of the number of channels required to record the signal with the highest recording bit rate among multiple recording signals. By configuring a magnetic recording/reproducing device having a rotary cylinder and a rotary cylinder, it is possible to select a recording/reproducing channel according to the recording bit rate of the recording signal and perform recording/reproducing. It can be recorded and played back.

Embodiment The present invention is a digital magnetic recording and reproducing device for video signals, and is capable of recording and reproducing a plurality of video signals with different recording bit rates in the same device by switching the channels of the magnetic head, circuit, etc., as an NTSC composite digital signal. A combination of band compressed NTSC composite digital signals is considered. Further, the plurality of video signals may be, for example, a combination of a high-definition MUSE digital signal and a signal obtained by band-compressing the high-definition MUSE digital signal. Further, the plurality of video signals may be, for example, a combination of an NTSC composite digital signal and a high-definition MUSE digital signal, and furthermore, a combination of an NTSC composite digital signal, a band-compressed NTSC composite digital signal, a high-visibility MUSE digital signal, and a high-definition MUSE digital signal. Various combinations of various signals can be considered, such as a combination of a signal obtained by band-compressing the MUSE digital signal and a signal obtained by band-compressing the high-visibility baseband signal.

Hereinafter, specific examples of the present invention will be described.

FIG. 1 is a block diagram of a magnetic recording/reproducing apparatus according to a first embodiment of the present invention. 101 is an input terminal, 1 is a D/A converter, 141 is a compression circuit, 142 is an expansion circuit, 143 is an error correction encoder, 144 is an error correction decoder, 145 is an error correction encoder, 148 is an error correction decoder , 151 is a divider, 154 is a multiplexer, 157 to 160 are error correction encoders, 168 to 171 are error correction decoders, 201 to
204 is a modulator, 221 to 224 are demodulators, 241 to 2
44 is a recording amplifier, 261 to 264 are playback amplifiers, 35
1 to 358 are switches, 301 to 308 are magnetic heads,
331 is a rotating cylinder, and 341 is a magnetic tape.

The signal applied to the input terminal 101 is an NTSC composite signal, and by switching the switches 351 to 358, the signal AI applied to the input terminal 101 can be changed to either the case of recording without band compression or the case of recording with band compression. A case where two types of recording signals are recorded and reproduced will be explained.

The sampling frequency was set to 14.3 MHz (4 MHz of color subcarrier frequency).
The NTSC composite signal is converted into a digital signal with 8 bits of quantization bits, and subjected to vertical and horizontal blanking processing, error correction encoding processing, data block ID addition processing, digital modulation processing, etc. .

As a result, the recording bit rate when recording without band compression is 119 Mbps, and the recording bit rate when recording with band compression is 30 Mbps. Therefore, from equation (1), the recording signal and recording bit rate when band compression is not applied are represented by B2 and R2, respectively, and the recording signal and recording bit rate when band compression is applied are represented by B1 and R1, respectively. . Also, the maximum recording bit rate per channel is 30 Mbl)s
The recording and reproducing channels, the diameter of the rotary cylinder 331, the rotation speed, and the
The magnetic tape 341 is wound at a corner, and the magnetic heads 301 to 3
The arrangement of 08 has been set.

In this example, the angle of the tape winding is 180'', and two sets of four magnetic heads are arranged at 180 degrees above the rotating cylinder.

First, the signal A! applied to the input terminal 101! The case of recording without applying band compression will be explained. Input terminal 101
The signal AI applied to is converted into a digital signal by an A/D converter 121, and subjected to vertical and horizontal blanking processing. Switch 351 is closed to connect A/D converter 121 and error correction encoder 145, and the output of A/D converter 121 is applied to error correction encoder 145.

By the way, the value of bit rate R2 = 119 Mbps
and r=30Mbl)s into equation (2), the value of the number N2 of recording and reproducing channels is determined. That is, N2=4 is found. The output of the error correction encoder 145 is applied to the divider 151, then divided into the four determined channels, and applied to the error correction encoders 157 to 160.
A data block ID is added. Switch 352 is closed to connect error correction encoder 143 and modulator 201, and the outputs of error correction encoders 157-180 are applied to modulators 201-204. Four modulators 201 to 20 perform digital modulation using a certain fixed coding method.
4 are applied using the same procedure. Modulators 201-204
The 4-channel output is achieved by a recording amplifier 241, each of which is composed of amplifiers capable of recording the maximum recording bit rate (r = 30 Mbl)s per channel.
~244. When recording, switch 355-35
8 are all closed to the recording side, and switches 355 to 358
and magnetic tape 341 via magnetic heads 301 to 308.
Information on 4 channels is recorded on the top.

On the other hand, during playback, the switches 355 to 358 are all closed to the playback side, and the 4
Channel information is applied to reproduction amplifiers 261-264 via magnetic heads 301-308 and switches 355-358. Each reproducing amplifier is configured to be capable of reproducing the maximum recording bit rate r=30 Mbps per channel. The four-channel outputs of the reproducing amplifiers 261-264 are applied to demodulators 221-224, and digital demodulation using a certain fixed coding method is performed in the same procedure in each of the four demodulators 221-224. Switch 354 is closed so that demodulator 221 and error correction decoder 168 are connected, and the four-channel outputs of demodulators 221-224 are applied to second error correction decoders 168-171. The outputs of the error correction decoders 168 to 171 are applied to the multiplexer 154, multiplexed, and then applied to the first error correction decoder 148. switch 35
3 is closed so that the error correction decoder 148 and the D/A converter 131 are connected, and the output of the error correction decoder 148 is converted to the original NTSC composite signal by the D/A converter 131, and the output terminal 111 is is output from.

Next, a case will be described in which the signal AI applied to the input terminal 101 is band-compressed and recorded. The signal AI applied to the input terminal 101 is converted into a digital signal by the A/D converter 121, and subjected to vertical and horizontal blanking processing. The switch 351 connects the A/D converter 121 and the compression circuit 14.
1, and the output of the A/D converter 121 is applied to the compression circuit 141. The signal subjected to band compression by the compression circuit 141 is applied to an error correction encoder 143, and a data block ID is added thereto. by the way,
Value of bit rate R1 R1=30MbpS and r=3
By inserting 0 M b p s into equation (2),
Number of recording/playback channels N! Find the value of. That is, N1=1 is found. Switch 352 is closed to connect error correction encoder 143 and modulator 201, and the output of error correction encoder 143 is applied only to modulator 201. Digital modulation using the above-mentioned fixed coding method is performed by one modulator 201 and applied to the recording amplifier 241. During recording, switch 355 is closed to the recording side, and switches 356 to 358 are open. One channel of information is recorded on the magnetic tape 341 via the switch 355 and magnetic heads 301 and 305.

On the other hand, during reproduction, switch 355 is closed to the recording side, and switches 356 to 358 are open.

One channel of information recorded on the magnetic tape 341 is applied to the reproduction amplifier 261 via the magnetic heads 301 and 305 and the switch 355. The output of the reproducing amplifier 261 is applied to the demodulator 221, where it is digitally demodulated using the predetermined coding method described above. switch 354
is closed so that the demodulator 221 and the error correction decoder 144 are connected, and the output of the demodulator 221 is connected to the error correction decoder 1.
44. The output of the error correction decoder 144 is applied to an expansion circuit 142 and subjected to band compression decoding.

The switch 353 connects the expansion circuit 142 and the D/A converter 131.
The output of the expansion circuit 142 is converted into the original NTSC composite signal by the D/A converter 131 and output from the output terminal 111.

Like this first embodiment, NTSC without band compression
When recording and reproducing a composite signal and a band-compressed NTSC composite signal, if the bit rate of the recording signal is 119 Mbps and 30 Mbps, respectively,
Maximum recording bit rate per channel is 30Mbps
1 The recording and reproducing channels, the diameter and rotation speed of the rotating cylinder 331, so that the total recording bit rate is 119 Mbps,
By setting the winding of the magnetic tape 341 at an angle and the arrangement of the magnetic heads, the NTSC composite signal without band compression and the NTSC composite signal with band compression can be recorded and played back in 4 channels in the same magnetic recording and playback device. Four channels and one channel of each system can be used for recording and reproduction.

FIG. 2 is a block diagram of a magnetic recording/reproducing apparatus according to a second embodiment of the present invention. 102.103 are input terminals, 11
2.113 is the output terminal, 121 is the A/D converter, 131
is a D/A converter, and 146.147 is an error correction encoder 1.
14θ, 150 is an error correction decoder, 152.153 is a divider, 155.156 is a multiplexer, 161 to 16
7 is an error correction encoder, 172 to 178 are error correction decoders, 205 to 208 are modulators, 225 to 228 are demodulators,
245-248 are recording amplifiers, 265-268 are playback amplifiers, 359-372 are switches, 309-316 are magnetic heads, 332 is a rotating cylinder, and 342 is a magnetic tape.

The signal applied to the input terminal 102 is an NTSC composite signal, and the signal applied to the input terminal 10'3 is a high-definition MUSE signal. Sui Sochi 359-372
A case will be described in which the signal AI applied to the input terminal 102 or the signal A2 applied to the input terminal 103 is recorded and reproduced by switching. It is assumed that the recording bit rate of the NTSC composite signal is 119 Mbps. The MUSE signal of 7~Ivision is converted into a digital signal with a sampling frequency of 16°2 MHZ N and a quantization bit of 8 bits, and subjected to error correction encoding processing.
It is assumed that the recording bit rate is 156 Mbl)s by performing data block processing, digital modulation processing, etc. Therefore, from equation (1), the recording signal and recording bit rate of the NTSC composite signal are B1 and R1, respectively.
The recording signal and recording bit rate of Hisilon's MUSE signal are represented by B2 and R2, respectively. In addition, the maximum recording bit rate r per channel is 40Mb.
ps, and the total recording bit rate is 158 Mbps.
The arrangement of 1 to 308 is set. In this example, the tape winding has an angle of 180', and two sets of four magnetic heads are arranged at a position of 1800 on the rotating cylinder.

First, a case will be described in which an NTSC composite signal applied to the input terminal 102 is recorded and reproduced. The switches 359 to 368 are connected to the input terminal 102 side, the output terminal 112 side, the error correction encoder 147 side, and the error correction encoder 1 side, respectively.
61 to 163, the error correction decoder 150, and the error correction decoders 172 to 174. Signal AI applied to input terminal 102 is converted into a digital signal by A/D converter 121 and applied to error correction encoder 147.

By the way, the value of bit rate R1 is R1=119Mbl:
By inserting +s and r=40 Mbps into equation (2), the value of the number Nl of recording and reproducing channels is determined.

That is, Nt=3 is found. The output of the error correction encoder 147 is applied to the divider 153, then divided into the three determined channels, and applied to the error correction encoders 161-163. The outputs of the error correction encoders 181 to 163 are sent to the modulator 20.
It is applied to three modulators 205-207 among the modulators 5-208. Digital modulation using a certain fixed coding method is applied to each of modulators 205 to 207 using the same procedure. The three-channel output of the modulators 205 to 207 is such that each recording amplifier has a maximum recording bit rate per channel of r = 4.
Three recording amplifiers 245 among the recording amplifiers 245 to 248, which are composed of amplifiers capable of recording 0 Mbps.
~247. Switches 369 to 37 when recording
1 is closed to the recording side, and switch 372 is open. Three channels of information are recorded on the magnetic tape 342 via switches 369-371 and magnetic heads 309-311, 313-315.

On the other hand, during reproduction, switches 369 to 371 are closed to the reproduction side, and switch 372 is open.

The three channels of information recorded on the magnetic tape 342 are applied to three reproduction amplifiers 265-267 among the reproduction amplifiers 265-268 via magnetic heads 309-311, 313-315 and switches 369-371. . Each reproducing amplifier is configured to be capable of reproducing the maximum recording bit rate r=40 Mbps per channel. The three-channel outputs of the reproducing amplifiers 265 to 287 are output from three demodulators 225 to 228 among the demodulators 225 to 228.
227, and the demodulators 225 to 227 perform digital demodulation using a certain fixed coding method using the same procedure. The three channel outputs of demodulators 225-227 are applied to error correction decoders 172-174. The outputs of the error correction decoders 172 to 174 are applied to a multiplexer 156, multiplexed, and then applied to the error correction decoder 150. The output of the error correction decoder 150 is converted into the original NTSC composite signal by the D/A converter 131 and output from the output terminal 112.

Next, the Hisilon MUS applied to the input terminal 103
The case of recording and reproducing the E signal will be explained. The switches 359 to 368 are connected to the input terminal 103 side, the output terminal 113 side, the error correction encoder 146 side, and the error correction encoder 1 side, respectively.
64 to 166, the error correction decoder 149, and the error correction decoders 175 to 177. Further, the A/D converter 121 and the D/A converter 131 use a clock of 14.3 MHz when processing the NTSC composite signal.

The clock when processing Hijoon's MUSE signal is 1
It is shared by setting it to 6.2MHz. Signal A2 applied to input terminal 103 is converted into a digital signal by A/D converter 121 and applied to error correction encoder 146. By the way, the value of bit rate R2 is R2=156
By entering Mbl)s and r=40 Mbps into equation (2), the value of the number N2 of recording and reproducing channels is determined. That is, N2=4 is found. error correction encoder 146
The output is applied to the divider 152, then divided into the four determined channels, and applied to error correction encoders 164-167. The outputs of error correction encoders 164-167 are applied to modulators 205-208. Digital modulation using the above-mentioned fixed coding method is applied to each of modulators 205 to 208 using the same procedure. 4 of modulators 205-208
The channel outputs are applied to recording amplifiers 245-248. During recording, all switches 389-372 are closed to the recording side, and information of four channels is recorded on magnetic tape 342 via switches 369-372 and magnetic heads 309-316.

On the other hand, during playback, the switches 369 to 372 are closed to the playback side, and the information of the four channels recorded on the magnetic tape 342 is transferred to the magnetic heads 309 to 316 and the switch 372.
The signals are applied to the reproduction amplifiers 265 to 268 via the signals 9 to 372. The four-channel outputs of the reproducing amplifiers 265 to 268 are applied to demodulators 225 to 228, and digital demodulation using the above-mentioned predetermined coding system is performed in the same manner. The four channel outputs of demodulators 225-228 are applied to error correction decoders 175-178. The outputs of the error correction decoders 175 to 178 are applied to the multiplexer 155, multiplexed, and then applied to the error correction decoder 149. The output of the error correction decoder 149 is sent to the D/A converter 1.
31, it is converted into the original high definition MUSE signal and output from the output terminal 113.

As in this second embodiment, when recording and reproducing an NTSC composite signal and a high-definition MUSE signal, the bit rates of the recording signals are 119 Mbps and 156 Mbps, respectively.
Mbps, the recording and reproducing channels and the rotating cylinder 33 are set so that the maximum recording bit rate per channel is 40 MbpSN total recording bits total recording bit rate ps.
By setting the diameter of 2, the number of revolutions, the angle of winding of the magnetic tape 342, and the arrangement of the magnetic head, the NTSC composite signal and the high-definition MUSE signal can be transmitted in a 4-channel recording/reproducing system within the same magnetic recording/reproducing device. 3 each
Recording and playback can be performed using channels and 4 channels.

In addition, as another example, a combination of a high-definition MUSE signal and a signal obtained by band-compressing the high-definition MUSE signal may be considered. In this case, the bit rates of the recording signal are R2=156Mbl)s and RI=78Mb, respectively.
l) If S, the maximum recording bit rate r per channel is 39 Mbps.

By setting the recording and reproducing channels, the diameter and rotational speed of the rotating cylinder, the angle of the magnetic tape winding, and the arrangement of the magnetic head so that the total recording bit rate is 156 Mbps, from equation (2), high-definition < 7) The band-compressed signals of the MUSE signal and the high-definition MUSE signal can be recorded and reproduced using 4 channels and 2 channels, respectively, of the 4-channel recording and reproduction system in the same magnetic recording and reproduction apparatus.

In addition, as another example, a combination of an NTSC composite signal, a band-compressed NTSC composite signal, a high-definition MUSE signal, a band-compressed signal of the high-definition MUSE signal, and a band-compressed signal of a high-definition baseband signal. can also be considered. In this case, the bit rate of each recording signal is R3 = 119Mb
I)s,! :R1=39Mbps and R4=158M
bps and R2 = 78Mbps and N5 = 1 (30Mbps
Then, the maximum recording bit rate r per channel is 40 M b p8 N The total recording bit rate is 160 M
b1) From equation (2), by setting the recording/reproducing channel, the diameter of the rotating cylinder, the rotation speed, the angle of the magnetic tape winding, and the arrangement of the magnetic head, the NTS
C composite digital signal and band compressed NTS
C-Funposit digital signal and high-definition MUS
The E digital signal, HiVigilon's MUSE digital signal, band compressed signal, and 71 Ivision baseband signal, band compressed signal are respectively 3 channels and 1 of the 4 channel recording/reproducing system in the same magnetic recording/reproducing device.
Recording and reproduction can be performed using channels, 4 channels, 2 channels, and 4 channels.

Furthermore, various combinations of various signals can be considered as input signals. Furthermore, although video signals have been described here, audio signals can also be handled in the same way as video signals.

Effects of the Invention As described above, by implementing the present invention, it is possible to record and reproduce a plurality of recording signals with different recording bit rates using the same magnetic recording and reproducing device, and the recording and reproducing system circuit, which was previously difficult to share, can be realized. and many of the mechanisms can be shared.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a magnetic recording and reproducing apparatus according to a first embodiment of the present invention, FIG. 2 is a block diagram of a magnetic recording and reproducing apparatus according to a second embodiment of the present invention, and FIG. 3 is a block diagram of a magnetic recording and reproducing apparatus according to a second embodiment of the present invention. FIG. 4 is a block diagram of a second conventional magnetic recording and reproducing apparatus. 101-107...Input terminal, 111-117...Output terminal, 121-125...A/D converter, 131-13
5...D/A converter, 141...Compression circuit, 142...
Extension circuit, 141,143,145~147.157~
167...Error correction encoder, 144.148-150.
I E38-178...Error correction decoder, 151-15
3... Divider, 154-156... Multiplexer, 2
01-214...Modulator, 221-234...Demodulator,
241-254...recording amplifier, 261-274...playback amplifier, 35-378...switch, 301-324
...Magnetic head, 331-334...Rotating cylinder, 3
41-344...Magnetic tape.

Claims (1)

[Claims] A multi-channel magnetic recording and reproducing device has the number of recording and reproducing channels required to record a signal with the maximum recording bit rate among multiple types of recording signals, and the number of recording and reproducing channels is determined according to the recording bit rate of each signal. A digital magnetic recording and reproducing method characterized in that a required number of recording and reproducing channels are selected from among the recording and reproducing channels, and the individual signals are recorded and reproduced.