JPS61234677A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To record plural TV signals which are inputted simultaneously, by recording plural video signals, whose time bases are matched to one another, with field skipping by two rotary magnetic heads. CONSTITUTION:A sound signal and a video signal of the first TV signal are applied to terminals 1 and 7. A sound signal and a video signal of the second TV signal are applied to terminals 1A and 7A. The first video signal passes a video signal recording processing circuit 8 and is mixed with a multiple sound signal by a mixer 36. The output of a recording amplifier 9 is supplied to a rotary magnetic head 21 through a changeover switch 14. The second video signal is applied to a time base matching circuit 31. The output of the circuit 31 is supplied to a rotary magnetic head 22 through a mixer 36A, a recording amplifier 9A, and the switch 14.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a magnetic recording and reproducing system in which a plurality of television signals are simultaneously recorded on a magnetic tape, and a plurality of television playback signals are simultaneously output from this tape. Regarding equipment.

[Conventional technology]

Figure 4 shows a conventional magnetic recording/reproducing device (hereinafter referred to as VTR)
1 is a block diagram showing an embodiment of the IL
, IR are stereo left (L) channel and right iR) channel audio signal input terminals, 2L and 2R are audio signal recording processing circuits that perform processing such as noise reduction and frequency modulation of audio signals, and 3L and 3R are playback terminals. Bandpass filter (BPF) that separates and extracts the audio signal from the signal, 4L
, 4R are audio signal reproduction processing circuits that perform processing such as frequency demodulation and noise reduction, and 5L and 5R are audio signal output terminals. 7 is a video signal input terminal; 8 is a video signal recording processing circuit that performs processing such as frequency modulating the luminance signal in the video signal, converting the frequency of the color signal in the video signal to a low frequency band, and synthesizing these signals; , 9 is a recording amplifier for supplying a signal obtained by mixing the outputs of the audio signal recording processing circuits 2L and 2H and the output of the video signal recording processing circuit 8 to the magnetic head as a signal at an appropriate level. In addition, 10 extracts the vertical synchronization signal from the video signal and converts it into 1
A vertical synchronization separation circuit that outputs a vertical synchronization signal whose frequency is divided by 2, 1) is based on a vertical synchronization signal whose frequency is divided by 1/2,
A control signal recording circuit that supplies a signal at a consistent level to the control head; 12 is a changeover switch; 13
1 is a control head for recording control signals on a magnetic tape or reproducing control signals from a magnetic tape; 14 is a changeover switch; 15'L; 1
5'R is a reproduction amplifier that amplifies the signal reproduced from the magnetic tape; 17 is a changeover switch; 18 is a demodulator that demodulates the frequency-modulated luminance signal and converts the low frequency-converted color signal to the original frequency; A video signal reproduction processing circuit performs processing such as synthesizing these signals and returns the reproduced signal to a video signal; 19 is a reproduced video signal output terminal; 20 is a circuit that alternately switches the outputs of the reproduction amplifiers 15L and 15R; This is a head switch pulse generation circuit that controls the changeover switch 17 to generate a continuous reproduction signal. 21 is a first rotating magnetic head for recording a mixed signal of a video signal and an audio signal on a magnetic tape or reproducing the mixed signal from a magnetic tape; 22 is a similar second rotating magnetic head; 24 is a rotary cylinder on which magnetic heads 21 and 22 are mounted with an angular interval of 180°;
This is a rotation detector for detecting the rotation phase of No. 3. 35
is a mixer that mixes the L and R channel audio signals, 3
6 is a mixer that mixes the audio signal and the video signal.

Further, the magnetic tape is approximately 1.
The magnetic tape is wound 80 degrees and runs diagonally, so that the magnetic heads 21 and 22 perform recording or reproducing scanning in diagonal directions with respect to the magnetic tape. In addition, the control head 13
is disposed at the lower end of the magnetic tape in the width direction, facing the magnetic tape, so that the control head 13 performs recording or reproduction in the longitudinal direction of the tape.

FIG. 5 is a diagram showing a tape pattern, where 40 is a magnetic chip, 42 is a control trunk, and 43 is an audio/video track.

FIG. 6 is a diagram showing the relationship between the spectrum of video and audio signals, where Y is the luminance signal component in the video signal, C is the color signal component in the video signal, L is the L channel component of the audio signal, and R is the L channel component of the audio signal. The L channel component of the audio signal is shown.

Next, the operation will be explained.

During recording, each stereo audio signal corresponding to the television signal to be recorded is input to the audio signal input terminal LL.
.

These signals become frequency modulated signals with carrier frequencies different from each other, and are multiplexed by the next mixer 35. Further, the video signal of the television signal is applied to the video signal input terminal 7, and this signal is applied to the video signal recording processing circuit 8, where it is passed through a low-pass filter (LPF).
and a bandpass filter (BPF) to separate the signal into a luminance signal and a color signal, respectively. And once above the signal is pre-emphasized and clamped.

After processing such as white clipping, it is modulated with the same wave number and becomes an FM signal.On the other hand, the color signal is subjected to burst emphasis, etc., and then the frequency is converted to a low frequency band. and the above-mentioned FM signal are combined at appropriate levels and output from the video signal recording processing area @8.

The audio signal and video signal obtained as described above are mixed in a mixer 36. The spectrum of this mixed signal is as shown in FIG. The signals mixed in this way are amplified by the recording amplifier 9, and sent to the rotary cylinder 23 via the recording side contact R of the changeover switch 14.
The audio signal is supplied to the first and second rotary magnetic heads 21 and 22 installed at an angular interval of 80 degrees, and forms a 1-rack 43 diagonal to the magnetic tape 40 as shown in FIG. A mixed signal of the video signal and video signal is recorded.

The video signal applied to the input terminal 7 is also applied to the vertical synchronization separation circuit 10, where only the vertical synchronization signal is extracted from the video signal. Then, this vertical synchronization signal is further frequency-divided by 1/2, and this 1/2-frequency-divided vertical synchronization signal is applied to the next control signal recording circuit 1).
The waveform is shaped. This waveform-shaped control signal is guided to the control head 13 via the recording side contact R of the changeover switch 12, and is sent as a pulse signal to the control trunk 42 located at the side edge of the magnetic tape 40 as shown in FIG. recorded.

Furthermore, during recording, a servo circuit (not shown)
The rotation of the cylinder 23 is controlled so that it rotates in synchronization with the output of the vertical synchronization separation circuit 10, and its phase is also controlled so that it has a predetermined value. Therefore, while the rotary cylinder 23 makes half a revolution, one magnetic head records exactly one track of one field of the video signal, and during the next half revolution, the other magnetic head records the next one field. One track for one word is recorded next to each other, and this process is repeated to form tracks one after another.

Also, the position where the vertical synchronization signal in the video signal is recorded is controlled by the servo to be a position slightly inside the starting edge of the video track (the lower end of the diagonal track in Figure 5), as shown in Figure 5. The phase of the rotary cylinder 23 is adjusted so as to be at a fixed position at the lower end of the video track, that is, the V-sync position shown in the figure. The reason for this is that the seam of the reproduced video signal is located in the overscan area at the bottom of the television screen, so that the seam on the screen is not noticeable.

As described above, audio signals and video signals are recorded as diagonal tracks on the magnetic tape 40, and the recording pattern is as shown in FIG. 5, as described above. In FIG. 5, the trunk 43 consists of tracks T1 and T2, track T1 is formed by the magnetic head 21, and track T2 is formed by the magnetic head 22. Also, in these tracks, both of the above audio signals are sequentially recorded in the fifth track.
As shown in the figure, A1. A2. . . , each field of the video signal is recorded as p1. p, 2゜...
· are recorded in order, and as shown in FIG. 5, Pl.

p2. Arranged in this order.

During playback, the magnetic head 2 is moved from the track T1 and the trunk T2 of the track 43 of the magnetic tape 40, respectively.
1 and 22, a mixed signal of an audio signal and a video signal is sequentially reproduced, and the video signal among these is sequentially reproduced in fields PI, p2. ... video signals are played back. This mixed signal is applied to the reproduction amplifiers 15L and 15R via the reproduction side contact P of the changeover switch 14.
L.

The output of 15R is applied to the changeover switch 17.

Here, this switch 17 is controlled by a switch pulse generated by a head switch pulse generation circuit 20 based on a signal from a rotation detector 24, and alternately switches the head output to output a continuous reproduction signal.

The reproduced mixed signal consisting of the audio signal and video signal obtained in this way is transmitted to the BPFs 3L and 3R belonging to the following audio systems.
The signal is applied to the video signal reproduction processing circuit 18, which is a video system. In BPF3L and 3R, □ is respectively,
- The frequency modulation signal corresponding to the R channel is separated and extracted and guided to the next audio signal reproduction processing circuits 4L and 4R, respectively. Here it is.

Both R signals are frequency demodulated 1. Processing such as de-emphasis and noise reduction is applied, and the original audio signal is restored.
Next, each audio signal output terminal 5L.

5R to obtain audio playback output.

On the other hand, the mixed signal applied to the video signal reproduction processing circuit 18 is separated into an FM signal and a low-pass converted color signal by a high-pass filter (HPF) and a low-pass filter (LPF), respectively. , FM signal is dropout corrected, amplitude limited, and demodulated.

Processing such as de-emphasis is performed and the signal is returned to a luminance signal, and the color signal is subjected to processing such as automatic level control 1 frequency conversion, burst compression, and jitter correction, and is returned to the original color signal. The color signal and the luminance signal are then combined back into a video signal. The output of the video signal reproduction processing circuit 18 obtained in this manner is led to the video signal output terminal 19, and a reproduced video signal is obtained.

Furthermore, during this reproduction, the rotary cylinder 23 is rotated at a constant rate at the frame frequency (1/2 of the field frequency) of the video signal, and the control nose reproduced by the control head 13 from the control trunk 42 of the magnetic tape 40 is transmitted. , is supplied to a servo circuit (not shown) through the reproduction side contact P of the changeover switch 12, and thereby controls the feeding of the magnetic tape 40, so that the magnetic head 21 correctly controls the track T1, and the magnetic head 22 correctly controls the track T2. It is controlled to scan.

As described above, during playback, the playback audio signal and the playback video signal are output to the output terminals 5L, 5R and the output terminal 19, respectively.
can be obtained.

[Problem that the invention seeks to solve]

Conventional VTRs are configured as described above, so while recording one television program, you cannot record another television program, and if you try to record two television programs at the same time, the device There were problems in that it was necessary to prepare two sets of magnetic tape, and two volumes of magnetic tape had to be prepared.

The present invention was made in order to solve the above problems, and it is possible to record two television signals on one magnetic tape at the same time, and also to provide a magnetic recording and reproducing system that can reproduce the two television signals at the same time. It provides equipment.

(Means for Solving the Problems) A magnetic recording and reproducing apparatus according to the present invention includes a time axis alignment circuit that mutually aligns the time axes of video signals of a plurality of input television signals, and a time axis alignment circuit that mutually aligns the time axes of video signals of a plurality of input television signals, and a A video signal recording processing means for extracting a video signal of the first period, a mixing means for mixing a multiplexed audio signal obtained by multiplexing a plurality of sounds with the video signal, and a 21-piece rotary magnetic head alternately records the mixed signal on a magnetic tape. recording and reproducing means for recording and reproducing the television signals; audio signal reproduction processing means for extracting audio signals corresponding to each television signal from the mixed signals alternately reproduced by the head; and reproduced video reproduced from the mixed signals. A memory for storing a signal, and a video signal interpolation means for synthesizing the signal read from the memory and the reproduced video signal into a temporally continuous video signal, and audio corresponding to a plurality of television signals at the same time. and video signals are obtained from the respective output terminals.

[Effect]

In this invention, two rotating magnetic heads are used to simultaneously record multiple video signals whose time axes have been aligned skipping fields, and to record multiple audio signals as multiplexed signals mixed with the video signal. It is possible to record a plurality of input television signals, and during playback, interpolate the played video signal with skipped fields using the playback signal stored in the memory to obtain a continuous playback output. These allow multiple television signals to be recorded simultaneously and multiple television signals to be simultaneously output as playback signals.

〔Example〕

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing a VTR according to an embodiment of the present invention, and in the figure, 1. IA is the 1st. Second
The audio signal input terminals, 2.2A, are the first and second audio signal input terminals, respectively. The second audio signal recording processing circuit, 3°3A is a BPF, and 4.4A is a first audio signal recording processing circuit. Second audio signal reproduction processing circuit, 5.5A
are the first and second audio signal output terminals, respectively. 7.
7A is the 1st. Second video signal input terminal, 8, 8
A is the first. The second video signal recording processing circuit, 9°9A, is connected to the first video signal recording processing circuit, respectively. A second recording amplifier, 10 is a vertical synchronization separation circuit, 1) is a control signal recording circuit, 12 is a changeover switch, and 13 is a control head.

Further, 14 is a changeover switch, and 15.15A is a first switch. The second regeneration amplifier, 18.18A, is the first
．． The second video signal reproduction processing circuit, 19.19A, is connected to the first video signal reproduction processing circuit, respectively. a second reproduced video signal output terminal, 20 a head switch pulse generation circuit, 21 a first . A first rotating magnetic head for recording a multiplexed audio signal mixed with a second audio signal and a first video signal on a magnetic tape, or for reproducing the multiplexed audio signal and the first video signal from a magnetic tape. ,2
2 is a second rotating magnetic head for recording the mixed multiplexed audio signal and the second video signal on a magnetic tape, or for reproducing the multiplexed audio signal and the second video signal from the magnetic tape; These rotating magnetic heads 21 and 22 are 180
The rotary cylinders 24, which are mounted at intervals of .degree., are rotation detectors for detecting the rotational phase of the rotary cylinders 230.

25 is a synchronization separation circuit for extracting vertical and horizontal synchronization signals from the first video signal introduced from the first video signal input terminal 7; 26 is a first video signal reproduction processing circuit 18;
an analog memory or an analog-to-digital converter (A/D) consisting of a charge-coupled device (CCD) for storing the output of and reading out the stored output at any time;
28 is a similar memory circuit; 27 is a first
The output of the video signal reproduction processing circuit 18 and the memory circuit 26
a changeover switch for alternately switching the output of the output and sending a continuous reproduction signal to the first video signal output terminal 19;
29 is a changeover switch for alternately switching between the output of the second video signal reproduction processing circuit 18A and the output of the memory circuit 28 and sending a continuous reproduction signal to the second video signal output terminal 19A; 30 is a head switch; Pulse generation circuit 2
This is an inverter for inverting the output of 0.

Further, 31 is a time axis adjustment circuit composed of memories similar to the above-mentioned memories 26 and 28 in order to synchronize the video signal introduced from the second video signal input terminal 7A with the first video signal. . 35 is a mixer that mixes the outputs of both the audio signal recording processing circuits 2 and 2A, 36 is a mixer that mixes the output of the video signal recording processing circuit 8 and the output of the mixer 35, and 36A is a video signal recording processing circuit 8A. output of mixer 3
This is a mixer that mixes the output of 5.

In addition, the magnetic tape is arranged and run in the same manner as in the conventional example above,
Recording or reproduction is performed with the same scanning locus as in the conventional example. Also, the recording spectra of the video signal and audio signal are configured similarly to the conventional example shown in FIG.
In the figure (, L+R) band is the 1st. This becomes the band of the second audio signal.

Next, the operation will be explained.

First, the time of recording will be explained. Of the two types of television signals to be recorded, the audio signal and video signal of the first television signal are applied to the first audio signal input terminal 1 and the first four video signal input terminals 7, respectively. The audio signal and video signal of the No. 2 television signal are respectively applied to the second audio signal input terminal IA and the 2.0 video signal input terminal 7A. Examples of waveform diagrams of each of these signals are shown in FIG. 2A, B, C, and D in order. The above two types of audio signals are processed by noise reduction, pre-emphasis, frequency modulation, etc. in audio signal recording processing circuits 2 and 2A, respectively, and then both are combined by a mixer 35 to form a multiplexed audio signal. Become. Although the audio carrier of the multiplexed frequency modulated signal is assumed to be two carriers here, it is also possible to use a carrier.

On the other hand, the first video signal introduced from the first video signal input terminal 7 is applied to the first video signal recording processing circuit 8, where it is separated into a luminance signal and a color signal. The signals are mixed after being subjected to the same processing as described in the prior art example, and become the output of the video signal recording processing circuit 8. Next, the output and the multiplexed audio signal are mixed in a mixer 36 and applied to the next first recording amplifier 9 for amplification. The output of the recording amplifier 9 is supplied via the recording side contact R of the changeover switch 14 to the first rotating magnetic head 21 of the two rotating magnetic heads mounted on the rotating cylinder 23 with an angular interval of 180°. be done. The rotating magnetic head 21 is attached to the rotating cylinder 23 at an angle of 18 mm.
While contacting the magnetic tape wound over 0° and making a half rotation, the multiplexed audio signal and the video signal are simultaneously recorded. The first field P1 is recorded as schematically shown by the solid line. During the next half rotation, the rotating magnetic head 21 does not come into contact with the magnetic tape, so no signal is recorded, and only one of the first video signals is recorded.
As shown by the dotted line F in FIG. 2, the second field P2 is not recorded on the magnetic tape.

In this way, along with multiplexed audio signals, pl, p3゜P5
... are extracted and recorded.

The first video signal is also applied to the vertical synchronization separation circuit 10, where the vertical synchronization signal whose frequency has been divided into 1/2 is extracted and applied to the next control signal recording circuit 1) to form a waveform. Shaped. This waveform-shaped control signal is applied to the control head 13 via the recording side contact R of the changeover switch 12, and is recorded as a pulse signal on the side edge of the magnetic tape. As described in the conventional example, the output of the vertical synchronization separation circuit 10 is applied to a servo circuit (not shown), and the servo circuit causes the cylinder 23 to rotate in synchronization with the output. The rotational phase is also controlled to a predetermined value.

In addition, a second video signal introduced from the second video signal input terminal 7A
The video signal is applied to the time axis alignment circuit 31. The time axis adjustment circuit 31 is composed of a memory that stores signals as described above and reads out the signals described above at an arbitrary time, and first writes the second video signal to the memory, and then Based on the vertical synchronization signal and horizontal synchronization signal extracted by the synchronization separation circuit 25 from the video signal of sugar 1, the vertical synchronization signal and horizontal synchronization signal of the second video signal read from the memory are added to these reference signals. The readout circuit of the memory is controlled so that the time axes of the memory coincide with each other. In this way, the first video signal and the second video signal are time-aligned. This situation is shown in Figure 2, No.H. That is, after the second video signal shown in the second diagram is written to the memory, it is read out with a delay as shown in E of the diagram, and the time axis is aligned with the first video signal shown in B of the diagram. .

The second video signal obtained in this way is applied to the second video signal recording processing circuit 8A, and after being subjected to the same processing as described for the first video signal recording processing circuit 8, it is mixed. 36A. The mixer 36A mixes the processed video signal and the multiplexed audio signal, and the mixed signal is applied to the next second recording amplifier 9A and amplified. The output of the recording amplifier 9A is supplied to the second rotating magnetic head 22 via the recording side contact R of the changeover switch 14, and the head 22 is in contact with the magnetic tape.
The multiplexed audio signal and the second video signal are recorded during the period. Since this period is located after the period in which the first rotating magnetic head 21 contacts the magnetic tape, the multiplexed audio signal is recorded continuously following the previous period without interruption, and the video signal is recorded as shown in FIG. As shown in G, as shown by the solid line in the second video signal, the first field Q
1 is recorded.

During the dotted line period shown in FIG. 2G, the second magnetic head 22 is in contact with the magnetic tape and is thick, so the second field Q2 is not recorded on the magnetic tape. In this way, Ql, Q3 . Q5.・
... are extracted and recorded.

As described above, the multiplexed audio signal in which the first and second audio signals are synthesized, the first and second video signals, and the control signal are transferred to the magnetic data 140 at the upper end of the magnetic tape as shown in FIG. Tracks 43 are formed by rotating magnetic heads 21 and 22. Of these, the trunk T1 is recorded by the rotating magnetic head 21, and the signal of a certain section of the first video signal, that is, the L field section, is recorded intermittently as PI, P3, . P5. It is recorded as follows. The track T2 is recorded by the rotating magnetic head 22, and together with the d-voice multiplexed signal that follows the multiplexed audio, the signal of a fixed section of the second video signal, that is, one field section, is recorded intermittently, Ql, Q3. ．． Q5. It is recorded as follows. In this way, each video signal is recorded intermittently for each field, but the audio signal is recorded continuously at A1, A2, . A3. It is recorded as follows. At this time, the vertical synchronizing signal is recorded at a fixed position on each track as in the conventional example, and a control track 42 is further formed by the control head 13.

Here, video signals of normal television signals are very similar signals in adjacent fields, for example, in the first video signal, Pl and p2. p2 and P3.
P3 and P4. ..., in the second video signal, Ql and Q2. Q2 and Q3. Q3 and Q4. ..., etc. are formed by signals that are very similar to each other. The video output during playback, which will be described below, takes advantage of this property and is made into a continuous signal.

As described above, both video signals are extracted and recorded intermittently in time every half rotation of the rotating magnetic head, and the audio signal is recorded continuously in time.

Next, the time of reproduction will be explained.

The rotary cylinder 23 is rotated at a constant speed in the same manner as described in the conventional example described above, and the feed control of the magnetic tape 40 is performed in the same manner as in the conventional example described above, so that the rotary magnetic head 21 moves the track T1 by the rotary magnetic head. 22 correctly scan trunk T2.

From the tracks T1 and T2 of the magnetic tape 40, the first . The second rotating magnetic heads 21 and 22 reproduce a mixed signal of the multiplexed audio signal and the first video signal, and a mixed signal of the multiplexed audio signal and the second video signal, respectively, and the reproduction side contact P of the changeover switch 14 through the first . It is applied to the second reproducing amplifier 15.15A. A portion of the remixed signal amplified by these reproducing amplifiers 15.15A is guided to the changeover switch 17. This changeover switch 17 is connected to a head switch pulse generation circuit 20.
The switching is performed every half rotation of the rotary cylinder 23 by the output of the changeover switch 17, and a continuous mixed signal is obtained at the output of the changeover switch 17. The mixed signal thus obtained has a BPF of 3.3
A, and a first audio signal and a second audio signal are separated and extracted from this mixed signal. These are the first. The second audio signal reproduction processing circuits 4 and 4A perform frequency demodulation and de-emphasis, respectively.

Processing such as noise reduction is performed to restore the original audio signal, and the first audio reproduction signal and the second audio reproduction output are simultaneously output to the audio signal output terminal 5.5A.

On the other hand, a part of the output of the reproduction amplifier 15.15A is supplied to the first . The signal is also applied to the second video signal reproduction processing circuit 18.degree. 18A to perform reproduction processing of the video signal included in the mixed signal. Here, at the output end of the reproduction amplifier 15, fields PI, P3 . P5.
... are sequentially and intermittently outputted, and the second video signal fields Qi, Q3 . Q5
．． ... are sequentially and intermittently output, and these are applied to the first video signal reproduction processing circuit 18 and the second video signal reproduction processing circuit 18A to perform the same processing as described in the explanation of the conventional example above. Receive pl, P3. P5. ..., and Ql
, Q3. Q5. ... are returned to the original video signal. The first video signal and second video signal thus obtained are applied to the next memory circuit 26 and memory circuit 28, respectively.

The memory circuit 26 writes one field at a time of the reproduced first video signal using the high level (“H”) of the pulse generated by the head switch pulse generation circuit 20.
Control is performed to read out the one field at the low level ("L") of the pulse.

The first video signal from the video signal reproduction processing circuit 18 and the first video signal read out from the memory circuit 26 are guided to the next changeover switch 27. The switch 27 is switched by the output of the head switch pulse generating circuit 20, so that a continuous video signal is obtained at the output of the switch 27. That is, each field is Pl, P, i.

p3. p3. , p5. , p5. . . , the first video signal is output twice, and the reproduced output of the first video signal is obtained at the first video signal output terminal 19. Note that in this output, the same field is repeated twice, but as mentioned above, the original video signal is very similar between adjacent fields, so although this involves a decrease in resolution, it is not practical for normal television signals. I can provide enough.

The operations of the memory circuit 28 and subsequent changeover switch 29 are also similar to those described above, except that the write and read timings need to be reversed from those of the memory circuit 26. Therefore, the pulse generated by the head switch pulse generation circuit 20 is inverted by the inverter 30 and applied to the memory circuit 28 and the changeover switch 29. In this way, the second video signal output terminal 19A receives the consecutive video signals Ql, N, Q3, . Q3. Q5. Q5. ...
is obtained. In this way, the first video signal and the second video signal are simultaneously output to the first video signal output terminal 19 and the second video signal output terminal 19A.

As described above, in this embodiment, two types of television signals are simultaneously recorded on the same magnetic tape, and the 2N type television signals can be simultaneously reproduced. Therefore, two television programs can be simultaneously recorded and reproduced on one roll of magnetic tape using one device, which has great practical value.

In the above embodiment, two types of video signals are recorded by extracting one field every two fields, but this is not limited to two types, but two or more types, for example, three types. The video signal may be recorded, in which case one field out of every three fields is extracted and the tracks on the tape are pt, Qi,
Rt, R4゜Q4. R4, R7, Q7. R7,-(Pn
, Qn.

(Rn indicates the field number n of each video signal), and when reproducing, write each reproduced signal and this to the memory, and read each of them twice in a period of 2 fields.Memory output It is only necessary to combine the two to form a continuous video signal. In this case, the audio signal is also made into three types of frequency modulation signals, then made into a multiplexed signal, mixed with the above video signal, recorded, separated during playback, and recorded and played back the audio corresponding to each video signal. good.

In addition, in the above embodiment, in order to align the second video signal with the time axis of the first video signal, time manipulation is performed by adjusting the delay time, while the audio is recorded as is, so that the video and the corresponding Although a time lag occurs in the audio, there is no practical problem as long as this lag is about one field. However, if precision is required, the audio signal may also be recorded with the delay time adjusted, or the delay time may be adjusted during playback.

Furthermore, in the above embodiment, to make each sound stereo, it is sufficient to increase the number of carriers of the frequency modulation signal, but it is also possible to make stereo sound without necessarily increasing the number of carriers.

Furthermore, in the above embodiments, the recording and re-transmitting systems for the two types of video signals are independent systems, but some of them may be shared. For example, since the heads 21 and 22 alternately record on the tape every half rotation of the cylinder 23, one system consists of the video signal recording circuit 8 and the recording amplifier 9, and the other system consists of the video signal recording circuit 8A and the recording amplifier 9A. Since these systems are used in common to form one system, the first video signal and the second video signal are output from the head switch pulse generation circuit 20, for example. It is also possible to alternately switch between the two and introduce the output into the above-mentioned shared system to supply the output to the heads 21 and 22. Similarly, the system consisting of the video signal reproduction processing circuit] 8 and the system consisting of the video signal reproduction processing circuit 18A may be made into one shared system. Also, time axis adjustment circuit 3
Since memory 1 is used only during recording, it may be used in place of memory 26 or 28 during playback.

In addition, the time axis alignment circuit 3'1 was applied only to the second input video signal to align the time axis with the first input video signal.
The reverse may be used, or it may be applied to both signals at the same time to align the time axes of both signals.

〔Effect of the invention〕

As described above, according to the present invention, when two or more types of video signals are extracted for each predetermined interval and recorded on a tape, the video signals are adjusted so that their time axes match each other. , separately recorded on each track, and at the time of playback, each played video signal is written into a memory, and the video signal read from the memory and the above-mentioned played video signal are combined to form a continuous video signal. , so that two types of video signals can be taken out simultaneously to each output terminal, and the audio signal is made into a multiplex audio signal, mixed with the video signal and recorded, separated and demodulated by BPF during playback, and multiplexed audio signals. Since the reproduced audio signals corresponding to the video signals can be simultaneously output to the respective output terminals, there is an effect that two types of television signals can be recorded or reproduced simultaneously with one device.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a magnetic recording/reproducing apparatus according to an embodiment of the present invention, FIG. 2 is a waveform diagram for explaining this embodiment, and FIG. 3 is a pattern diagram on a tape recorded according to this embodiment. , FIG. 4 is a block diagram showing an example of a conventional magnetic recording/reproducing device, FIG. 5 is a diagram of a pattern recorded on a tape recorded by the conventional device, and FIG. 6 is a spectrum diagram thereof. 2.2A...Audio signal recording processing circuit, 8,8A...
Video signal recording processing circuit, 21.22...Rotating magnetic head, 26.28...Memory circuit, 31...Time axis alignment circuit, 35.36.36A...Mixer. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Claims] (1) An audio signal recording processing means that frequency-modulates each audio signal corresponding to a plurality of television signals to be recorded, and then mixes them into a multiplexed audio signal, and an audio signal between each video signal of the plurality of television signals to be recorded. A time axis alignment circuit for aligning mutual time axes, a video signal recording processing means for sequentially extracting video signals of a certain period from each of the time-aligned video signals at predetermined intervals, and each of the extracted video signals. and a plurality of mixed signals outputted from the mixing means by the first and second rotating magnetic heads. recording and reproducing means for alternately and sequentially recording and reproducing on a magnetic tape, and separating and extracting each of the audio signals from a temporally continuous signal obtained by synthesizing the mixed signals from each of the rotating magnetic heads during reproduction, and frequency demodulation; a video signal reproduction processing means for reproducing each of the reproduced mixed signals to obtain a reproduced video signal, a memory circuit for storing each of the reproduced video signals, and the video signal reproduction processing means and a video signal interpolation means for synthesizing the reproduced video signal read from the memory circuit and the reproduced video signal read from the memory circuit to output a plurality of temporally continuous reproduced video signals. Device.