JPH0771249B2 - Magnetic recording / reproducing device - Google Patents

Description

The present invention relates to a magnetic recording / reproducing apparatus for video signals, and more particularly to slow reproduction thereof.

[Conventional technology]

In the current home VTR, in addition to the normal playback mode, a search playback mode that speeds up the running speed of the magnetic tape, a slow playback mode that slows down the running speed, and still image (still) playback with the tape stopped The mode is enabled.

In particular, with regard to the slow playback mode, it is known that after slowing the running of the magnetic tape, a tracking servo is applied to obtain a good slow playback image,
For example, in Japanese Unexamined Patent Publication No. 54-2018, instability due to insufficient motor torque generated when a magnetic tape is constantly run at a constant low speed is obtained by intermittently driving the magnetic tape at a constant speed. To achieve stable slow-motion playback images.

[Problems to be solved by the invention]

By the way, conventional slow playback, including the above-mentioned conventional technology,
The running speed of the magnetic tape is made slower than that at the time of recording, the same track is repeatedly reproduced and scanned a plurality of times, and the slow image reproduction is performed with the video signal reproduced by this, and multiple fields of the same image content are reproduced. I am trying to screen it. For this reason, there has been a problem that the reproduced image moves discontinuously and becomes unnatural.

An object of the present invention is to provide a magnetic recording / reproducing apparatus which solves such a problem and is capable of obtaining a slow reproduction image with smooth movement.

[Means for solving problems]

In order to achieve the above object, the present invention provides a standard in which a video signal having a field frequency n times as high as that of the standard system (where n is an integer of 2 or more) is input, and fields of n input video signals are included. A video signal of the standard system is formed, and a difference between two adjacent fields is represented for every n fields of the input video signal, and (n) having the same field length as the standard system.
-1) Also forming a number of difference signals, processing the video signal of the standard system and these difference signals, and simultaneously recording them on a recording medium,
During slow reproduction, the recording medium is run at a speed of 1 / n 'times (n' is an integer greater than or equal to n) times that during recording, and the video signal of the standard system having the same contents and the respective video signals are distributed over the n'field. After reproducing the difference signals and reproducing the respective difference signals, the respective difference signals are sequentially added to the n'fields having the same contents of the video signal of the standard system.

[Action]

By recording each of the difference signals described above in addition to the standard-system video signal composed of n fields of the input video signal, the entire input video signal is transformed and recorded. At the time of reproduction, by adding the difference signal to the video signal of the standard system as described above, the input video signal is restored by expanding each field to the time length of the standard system. The reproduced video signal thus obtained has a field whose contents are sequentially different between the fields of the video signal of the above-mentioned standard system, and therefore 1 / n 'slow reproduction whose content is different for each field. An image is obtained.

〔Example〕

 Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of a magnetic recording / reproducing apparatus according to the present invention. FIG. 1 (a) shows a recording system, FIG. 1 (b) shows a reproducing system, and 1 is an input terminal, 2,3 are A / D converters, 4,5 are field memories, 6 is subtractor, 7 and 8 are
D / A converter, 9 is BPF (band pass filter), 10 is
ACC circuit, 11 low frequency conversion circuit, 12 LPF (low pass filter), 13 and 14 AGC circuit, 15 and 16 LPF, 17 and 18 pre-emphasis circuit, 19 and 20 FM modulator, 21 switch, 22 is an adder, 23 is a recording amplifier, 24 is a magnetic head, 25 is a magnetic tape, 26 to 29 are input terminals, 31 is a reproduction head preamplifier,
32 is LPF, 33 is ACC circuit, 34 is high frequency conversion circuit, 35 is BPF, 3
6 is HPF, 37 is BPF, 38 and 39 are FM demodulators, 40 and 41 are de-emphasis circuits, 42 and 43 are LPFs, 44 is adders, 45 and 46 are A / D converters, 47 and 48 are field memories , 49 is adder, 50 is D / A
A converter, 51 is a switch, and 52 is an output terminal.

In FIG. 1A, a video signal from a video camera is input to the input terminal 1. A conventional video camera displays an image signal with a field frequency of 60 Hz, that is, one image is represented by one field, and 60 fields per second (that is,
Although 60 images are output, in this embodiment, the reading speed from the sensor of the video camera is doubled from the conventional one, and one image is formed and output every 1/120 second. This is shown in FIG. 2, where as shown in FIG. 2A, the fields from the video camera are F ₁ , F ₁ ′,
It is output in the order of F ₂ , F ₂ ′, F ₃ , F ₃ ′, .... here,
The fields F ₁ , F ₂ , F ₃ , ... with 1/60 second intervals and the other fields F ₁ ′, F ₂ ′, F ₃ ′, with 1/60 second intervals are separated by a solid line and a broken line. Different.

The video signal shown in FIG. 2 (a) input from the input terminal 1 is digitized by the A / D converters 2, 3 and then every other field F ₁ , F ₂ , F ₃ ,. Field memory 4
, Every other field F ₁ ′, F ₂ ′,
F ₃ ′ is written in the field memory 5. Here, the write clocks of the field memories 4 and 5 are input terminals 26 and 28.
Clocks CW1 and CW2 input from. These frequencies are usually 6 MHz or more, for example, 2f _sc , as can be seen from the sampling theorem, assuming that the band of the video signal is about 3 MHz.
(However, F _sc is the chrominance carrier frequency) is required it is 3f _sc or more, here, 3f _sc with a margin
The explanation will be made assuming that the clock of FIG. However, since the reading of the sensor of the video camera is performed at twice the speed of the conventional one, the video signal band of 3 MHz is normally doubled to 6 MHz. Therefore, the frequencies of the clocks CW1 and CW2 are 6f _sc .

Only when the fields F ₁ , F ₂ , F ₃ , ... are supplied from the A / D converter 2 to the field memory 4, the clock CW is supplied.
1, and the clock CW2 is supplied to the field memory 5 only when the fields F ₁ ′, F ₂ ′, F ₃ ′, ... Are supplied from the A / D converter 3. Such clocks CW1 and CW2 are obtained as follows. That is, in FIG. 3, gate pulses G ₁ and G ₂ of 60 Hz having opposite phases from a pulse signal S of 30 Hz (for example, a head switching signal) which is an operation reference of the video camera and the magnetic recording / reproducing apparatus.
To form. These gate pulses G ₁ and G ₂ are the fields F ₁ , F ₁ ′, F ₂ and F ₂ ′ of the video signal output from the video camera.
Although it is phase-locked with F ₃ , F ₃ ′, ..., Here, the gate pulse G ₁ has a high level at fields F ₁ , F ₂ , F ₃ ,.
The gate pulse G ₂ has field numbers F ₁ ′, F ₂ ′, F ₃ ′, ...
To high level. On the other hand, 6 from the reference clock generator
The reference clock CK at the frequency of f _sc is output, and the clock CW1 is obtained by gating the reference clock CK with the gate pulse G ₁ , and the clock CW2 is obtained by gating with the gate pulse G _2. can get.

Next, in the field memories 4 and 5, the clocks CW1 and CW2 are respectively
Clocks CR ₁ , C with 1/2 frequency (ie, 3f _sc )
Reading is done at R ₂ . Therefore, the fields F ₁ , F ₂ , F ₃ , ... from the field memory 4 every 1/60 second,
From the field memory 5, the field F ₁ ′,
F ₂ ′, F ₃ ′, ... Are read. Here, as shown in FIGS. 2A and 2B, fields F ₁ and F ₁ ′, F ₂
The read timings of the field memories 4 and 5 are set so that F ₂ ′ and F ₂ ′, F ₃ and F ₃ ′,. That is, although the writing of the field in the field memory 4 is ahead of the writing timing of the next field in the field memory 5 by 1/120 seconds, the reading timing of the written field in these field memories 4 and 5 is the same. Let

Each field F ₁ read from the field memory 4,
F _2, F _3, ......, after being an analog signal is sent to the D / A converter 7, the luminance signal of which the AGC circuit 13, LPF1
5.After passing through the pre-emphasis circuit 17, F with FM modulator 19
It is converted into an M-modulated signal and sent to the adder 22, and the chroma signal is B
It passes through the PF9 and ACC circuit 10, is converted into a low frequency conversion chroma signal by the low frequency conversion circuit 11 and LPF12, and is sent to the adder 22. In addition, the field F ₁ ′ read from the field memory 5,
The signals F ₂ ′, F ₃ ′ ... Are sent to the subtractor 6 and the difference signals (F ₁ ′ −F ₁ ), (F ₁ ′ −F ₁ ) from the fields F ₁ , F ₂ , F ₃ ... _{F 2 '- 2), (} F 3' -F 3), ...... it is made. This difference signal is converted into an analog signal by the D / A converter 8, and then the AGC circuit 14, LPF 16, pre-emphasis circuit 18
Then, it is FM-modulated by the FM modulator 20 and sent to the switch 21. When a video signal is input from a video camera that can read in 1/120 seconds, the switch 21 is connected to the contact a, and the FM modulation signal of the difference signal from the FM modulator 20 is shown in FIG. As shown in b), the FM modulation luminance signal,
It is combined with the low frequency conversion chroma signal. The combined signal is sufficiently amplified by the recording amplifier 23, then supplied to the magnetic head 24 and recorded on the magnetic tape 25.

When recording the video signal from the conventional video camera or the received video signal, the switch 21 is connected to the contact b, and the adder 22 uses the FM modulation luminance signal from the FM modulator 19 and the LPF 12 as in the conventional case. The low frequency conversion chroma signals from are added and recorded on the magnetic tape 25.

Here, the normal band of the LPF 15 for the luminance signals of the above-mentioned fields F ₁ , F ₂ , F ₃ , ... Is shown in FIG. 4 (a) and the difference signals (F ₁ ′ −F ₁ ), (F ₂ ′ − The normal band of the LPF 16 for F ₂ ), (F ₃ ′ −F ₃ ) ... is shown in FIG. 4 (b), respectively. The band of the luminance signal of fields ₁ , F ₂ , F ₃ , ... Is set to 3 MHz as in the conventional case, and for the difference signal, it is used only during slow reproduction, and especially as the difference signal information, the band is set. Bandwidth is limited to about 1.5MHz because it does not require.

FIG. 5 shows the recorded signal spectrum. The figure (a) is VH
As for the spectrum in the S standard VTR, FM carrier
It shows that it is 3.4MHz-4.4MHz. Further, FIG. 2B shows the FM carrier frequency of the FM modulator 20 as the FM carrier frequency of the FM modulator 19.
Higher than the carrier frequency (here, the Y-Y _D) FM-modulated difference signal to the upper sideband side of the conventional FM luminance signal indicating a state in which the frequency multiplexing. In recent years, it has become possible to record and reproduce considerably high frequency information by improving the magnetic tape and narrowing the magnetic head.

Next, signal processing during reproduction will be described with reference to FIG.

Fifth reproduced from magnetic tape 25 by magnetic head 24
The synthesized signal of the spectrum shown in FIG. 7B is sufficiently amplified by the reproduction head preamplifier 31, and then the low-pass exchange chroma signal is obtained by the LPF 32 and the FM modulation luminance signal is obtained by the HPF 36.
The difference signals are separated by the PF37.

The low-frequency conversion chroma signal separated by the LPF32 is made to have a constant amplitude by the ACC circuit 33, then converted by the high-frequency conversion circuit 34 into a band centered on the color subcarrier of the frequency f _sc , and band-limited by the BPF 35. After that, it is sent to the adder 44.

The FM-modulated luminance signal separated by the HPF36 is demodulated into a luminance signal by the FM demodulator 38, passed through the de-emphasis circuit 40, band-limited by the LPF42, and added by the adder 44 with the chroma signal from the BPF35 to form a composite signal. A video signal is formed.

Also, multiple recording is performed on the high frequency side of the FM modulated luminance signal,
The difference signal (Y−Y _D ) picked up by F37 is demodulated by the FM demodulator 39, then passes through the de-emphasis circuit 41, and LPF43
The band is limited by and is sent to the A / D converter 46.

LPF32, BPF35, LPF42 and LPF43 are respectively shown in FIG. 1 (a).
The same LPF12, BPF9, LPF15, and LPF16 in the recording system shown in can be used.

During normal reproduction, the switch 51 is connected to the contact b side, and the composite video signal output from the adder 44 is output to the output terminal 52 via the switch 51. That is, as shown in FIG. 2 (c), a video signal having fields F ₁ , F ₂ , F ₃ , ... Is outputted from the output terminal 52 at a field frequency of 60 Hz.

Conventionally, during slow playback (here, 1/2 slow playback), the running speed of the magnetic tape is set to 1/2 of that at the time of recording, and the same track is played back twice to scan for 1/30 second. The same image was output twice. That is, the same image of two fields is output, and therefore, the motion is lacking in smoothness and a beautiful slow reproduction image cannot be obtained.

On the other hand, in this embodiment, the second playback is performed during slow playback.
As shown in the figure (d), for example, the fields F ₁ , F ₂ , F ₃ , ... are output in the first 1/60 second of each 1/30 second, and 1/30 in the second half
It outputs fields F ₁ ′, F ₂ ′, F ₃ ′, and so on in 60 seconds, which makes it possible to obtain a fine slow-motion reproduction image.

Therefore, in FIG. 1B, the switch 51 is connected to the a side, and the composite video signal from the adder 44 is A /
Field memory 4 digitalized by D converter 15
At the same time as being written in 7, the difference signal from the LPF 43 is digitalized by the A / D converter 46 and written in the field memory 48.

Here, during 1/2 slow reproduction, the magnetic tape 25 runs at 1/2 speed of recording, and the magnetic head 24 reproduces and scans the same track twice. For this reason, the composite video signal output from the adder 44 repeats the same field as F ₁ , F ₁ , F ₂ , F ₂ , F ₃ , F ₃ , ... twice, and the difference signal (F ₁ ' −F ₁ ),
(F ₁ ′ −F ₁ ), (F ₂ ′ −F ₂ ), (F ₂ ′ −F ₂ ), (F ₃ ′ −
Repeat the same field as F ₃ ), (F ₃ ′ −F ₃ ) ,. And F ₁ and (F ₁ ′ −F ₁ ), F ₂ and (F ₂ ′ −F ₂ ),
The timings of F ₃ and (F ₃ ′ −F ₃ ), ... Match each other, and, as shown in FIG. 6, are in phase synchronization with the reference signal S of 30 Hz. Here, the reference signal S is at a high level at the preceding field of two fields having the same image content (for example, two fields F ₁ and F ₁ ) and is at a low level at the next field.

In the field memory 47, a continuous reference clock CK '(FIG. 6) having a frequency of 3f _sc from the input terminal 53 is supplied as a clock CW3 for writing, and the output signal of the A / D converter 45 is written. Similarly, in the field memory 48, the reference clock CK 'is supplied from the input terminal 55 as the clock CW4 for writing, and the output signal of the A / D converter 46 is written. Further, the reference memory CK ′ is supplied from the input terminal 54 to the field memory 47 as the clock CR3 for reading, and the written fields F ₁ , F are stored.
₁ , F ₂ , F ₂ , F ₃ , F ₃ , ... are read out sequentially. On the other hand, in the field memory 48, as shown in FIG.
The reference clock CK 'is supplied from the input terminal 56 as the read clock CR4 only when the reference signal S is at a low level. To this end, the field memory 48 is provided with two fields of the same image content (for example, field F ₁ ,
The latter field of F ₁ ) is the field memory 47.
When read from, the difference signal is read.

Fields from field memory 47 F ₁ , F ₁ , F ₂ , F ₂ ,
The composite video signal composed of F ₃ , F ₃ , ... And the intermittent difference signal from the field memory 48 at every other field are added by the adder 49. As a result, as shown in FIG. F ₁ , F ₁ ′, F ₂ , F ₂ ′, F ₃ , F ₃ ′, ...
A composite video signal V _out having a field frequency of 60 Hz is formed. The composite video signal V _out is converted into an analog signal by the D / A converter 50 and output from the output terminal 52 via the switch 51.

In this way, in this embodiment, the field of the same image content is not repeated twice, but the successive fields represent the image content according to the passage of time, so that a smooth slow reproduction image can be obtained. .

FIG. 7 is a block diagram showing another embodiment of the magnetic recording / reproducing apparatus according to the present invention. FIG. 7 (a) shows a recording system, FIG. 7 (b) shows a reproducing system, and 57-60. A D / A converter, 61 is a subtractor, and 62 is an adder, and the parts corresponding to those in FIG.

In FIG. 1, in the recording system, the signal input to the subtractor 6 is a digital signal, but in FIG. 7, the fields F ₁ , F ₂ , F ₃ , ... Read out from the field memory 4 are ...
The video signal of ... Is analogized by the D / A converter 57, and the field F ₁ ′, which is read from the field memory 5,
The video signals of F ₂ ′, F ₃ ′, ... Are converted into analog signals by the D / A converter 58, and the respective analog video signals are supplied to the subtractor 61 to obtain the difference signals (F ₁ ′ −F ₁ ), (F _{2 '-F 2), (F} 3' -
F ₃ ), ... are formed. Further, in FIG. 1, the signal input to the adder 49 in the reproduction system is a digital signal, but in FIG. 7, the signals read from the field memories 47 and 48 are respectively converted into D / A converters. After being converted to analog at 59 and 60, the adder 62 adds them. In other respects, the embodiment of FIG. 7 is similar to the embodiment of FIG.

Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments. That is, in the above-mentioned respective embodiments, the half slow reproduction is performed, but slower slow reproduction is possible in the same manner. That is,
In each of the above embodiments, the field frequency of the video signal from the video camera is 120 Hz.When recording this, the field frequency is 60 Hz and the difference signal of the same field frequency is recorded. The tape running speed was set to 1/2 the recording speed, and 1/2 slow image reproduction was performed.
By slowing down to 3 times, 1/4 times, ..., 1/3 slow image playback, 1/4 slow image playback, ... and slower slow image playback can be performed. In this case, for example, in FIG. 1B, a plurality of fields (for example, F ₁ , F ₁ , ...
...) from the second field to the field memory 48
The difference signals of the same contents from are added. Even with this, it is possible to obtain a slower reproduced image that is smoother than the conventional slow reproduced image having the same slow ratio. As described above, in the case of slower slow image reproduction, the field frequency of the video signal input to the input terminal 1 is further increased, and, for example, the field memory of FIG. 1 (a) and the field memory of FIG. By increasing the numbers respectively and increasing the number of difference signals and performing the same processing, it is possible to obtain a slow reproduction image with smoother movement.

In general, the field frequency of an input video signal is set to n (where n is an integer of 2 or more) times the field frequency f in the standard system, and the fields are sequentially set to F ₁ ¹ , F ₁ ² , ... F ₁ ^{When n} , F ₂ ¹ , F ₂ ² , ... F ₂ ⁿ , F ₃ ¹ , ..., Slow image reproduction in which the movement is slower than the slow ratio n can be performed. That is, for such an input video signal, for example, in the recording system shown in FIG. 1A, the A / D converter 3, the field memory 5, the subtractor 6, the D / A converter 8, the AGC circuit 14, the LPF 16 are provided. , A system comprising a pre-emphasis circuit 18, an FM modulator 20 and a switch 21 (hereinafter referred to as a difference signal system, while a system comprising a circuit from the A / D converter 2 to the FM modulator 19 is a main signal system. Are provided in parallel with the main signal system, and the field memory 4 of the main signal system and the field memories of the (n-1) difference signal system are used in the same manner as in the above embodiment. Video signal V ₁ consisting of F ₁ ¹ , F ₂ ¹ , F ₃ ³ , ... V ₁ F ₁ ² , video signal consisting of F ₂ ² , F ₃ ² , ... V ₂ F ₁ ⁿ , F ₂ ² , F ₃ ^A video signal V _n composed of ⁿ , ...
Of the difference signal (V ₂ −V ₁ ), (V ₃
-V _2), ......, the video signal V ₁ simultaneously recorded to obtain _{(V n -V n-1)} . The reproducing system, 1 / n of the time of recording the traveling speed of the magnetic tape '(where, n' is an integer equal to or greater than n) and, for example, as is clear from Fig. 1 (b), the reproduced video signal V ₁
Difference signals (V ₂ −V ₁ ), (V ₃ −V ₂ ), ..., (V _n −V _n-1 ) are added (in this case, the addition start timing of each difference signal is sequentially set to one or more fields). Each field of the input video signal is restored. As a result, a 1 / n ′ slow reproduction image with smooth movement can be obtained. It goes without saying that when n '= n, the slow reproduction image with the smoothest movement can be obtained.

Therefore, the slow ratio is determined by the running speed of the magnetic tape during recording, but the smoothness of the motion of the slow reproduced image is determined by the field frequency of the input video signal.

Also, the difference signals (F ₁ ′ −F ₁ ), (F ₂ ′ −F ₂ ), (F ₃ ′ −
The recording method of F ₃ ) ... is not limited to frequency multiplexing, and other methods such as recording in the deep portion of the magnetic tape are also possible and are not particularly limited.

〔The invention's effect〕

As described above, according to the present invention, it is possible to obtain a slow motion reproduced image with smooth movement.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a magnetic recording / reproducing apparatus according to the present invention, and FIG. 2 is an operation explanatory view of this embodiment.
FIG. 4 is a diagram for explaining the operation of the field memory of the recording system in FIG. 1, FIG. 4 is a diagram showing the bands of the luminance signal and the difference signal in FIG. 1, and FIG. 5 (a) is a conventional magnetic recording / reproducing apparatus. FIG. 5B is a spectrum diagram of the recording signal, FIG. 5B is a spectrum diagram of the recording signal in FIG. 1, FIG. 6 is an operation explanatory diagram of the field memory of the reproducing system in FIG. 1, and FIG. 7 is magnetic recording according to the present invention. It is a block diagram which shows the other Example of a reproducing | regenerating apparatus. 4,5 ... Field memory, 6 ... Subtractor, 47,48 ... Field memory, 49 ... Adder.

Continuation of the front page (72) Inventor ▲ Yoshi ▼ Atsushi Oka 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Home Appliances Research Laboratory, Hitachi, Ltd. (72) Inventor Makoto Shiomi 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Ceremony Company Home Appliance Research Laboratory, Hitachi, Ltd.

Claims (4)

[Claims] 1. A video signal having a field frequency of n times the field frequency f of the standard system (where n is an integer of 2 or more) is used as an input signal, and a video signal consisting of fields every 1 / f of the input signal is used. The first video signal V ₁ is composed of a field delayed by (i−1) / nf (where i = 2, 3, ..., N) from the field of the _first video signal V _1. The video signal is the i-th video signal V ₁ and the input signal is n
Number of video signals _{V 1, V 2, V 3} , ......, and the first means for dividing the V _n, wherein n number of video signals _{V 1, V 2, V 3} , ......, each field V _n To the time length of 1 / f, and delaying the first video signal V ₁ by (n-1) / nf to obtain the i-th video signal V ₁ (n-i). second means for phase-matching the fields of the _n video signals V ₁ , V ₂ , V ₃ , ... The n video signals V ₁ , V ₂ ,
From V ₃ , ..., V _n , (n-1) difference signals (V ₂ −V ₁ ),
(V ₃ −V ₂ ), ..., (V _n −V _n−1 ) forming third means, and the first video signal V ₁ and the _first video signal V ₁ output from the second means. (N-1) difference signals (V _{2
-V 1), (V 3 -V} 2), ......, and fourth means for recording the (V _n -V _n-1) and the respective process to concurrently recording medium, at the time of recording the recording medium The first video signal V ₁ and the (n-1) number of difference signals are made to run at a speed of 1 / n 'times (where n'is an integer equal to or greater than n) so that the same field is repeated. (V ₂ −V ₁ ), (V ₃ −V ₂ ), ..., (V _n −V _n−1 ) are simultaneously reproduced and processed, and the fifth means is used. Each of these signals is supplied,
The first field is set as the field of the first video signal V ₁ for each n ′ field of the time length n ′ / f in which these signals repeat, and the kth field (where k = 2, 3, ..., n) to the field of the first video signal V ₁ and the difference signals (V ₂ −V ₁ ), (V ₃ −
V ₂ ), ..., (V _k −V _k−1 ) are added, and the (n
The (n-1) th difference signals (V ₂ −V ₁ ) and (V ₃ −) are added to the first video signal V ₁ from the +1) th to n′th fields.
V ₂ ), ..., (V _n −V _n-1 ), and a sixth means for forming a video signal, and 1 / n ′ slow motion reproduction in which the contents change from field to field A magnetic recording / reproducing apparatus characterized by being configured to obtain an image. 2. A magnetic recording / reproducing apparatus according to claim 1, wherein the processing of the first and second means is performed by a field memory. 3. A magnetic recording / reproducing apparatus according to claim 1, wherein the fifth means is a field memory. 4. The method according to claim 1, wherein the first video signal V ₁ is FM-modulated, and the difference signal is FM-modulated to a frequency band higher than that of the _first video signal V _1. Then, the magnetic recording / reproducing apparatus is characterized in that the processing of the fourth means is performed by frequency-multiplexing the _first video signal V ₁ and recording it on the recording medium.