JPH03297295A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To improve quality of a reproduced picture and a reproduced audio signal by expanding a tape recording available time without modification of a tape format. CONSTITUTION:In the case of expanding a tape recording available time, one field period of an FM luminance signal YFM and a low frequency conversion chroma signal CL from TBC 9, 16 is increased to 5/4 with respect to one field period of an input luminance signal and an input chroma signal Cn. Thus, one field each of the FM luminance signal YFM and the low frequency conversion chroma signal CL is recorded on each track formed on a magnetic tape 25. Since video signals for 150min are thinned by 2 fields each per 10 fields, the number of fields of the video signal is equal to the number of fields for 60min, and the video signals for 150min are recorded on the magnetic tape 25.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a helical scan type magnetic recording and reproducing device for recording and reproducing video signals, and in particular, to extend recording time and shorten reproducing time. The present invention relates to a magnetic recording/reproducing device capable of performing.

[Prior Art] In a conventional helical scan type magnetic recording/reproducing device f (hereinafter referred to as a VTR), the remaining amount of magnetic tape to be used is smaller than the length of the broadcast program to be recorded (hereinafter referred to as the required recording time). If the recordable time length (hereinafter referred to as tape recordable time) is short and the entire broadcast program cannot be recorded only in 5p (411! quasi) mode, for example, the tape recording method disclosed in Japanese Patent Application Laid-Open No. 63-94451 In order to increase the tape recordable time by combining SP mode and long-time mode (a mode in which recording is performed at a slower magnetic tape running speed (hereinafter referred to as tape speed) than in SP mode), the above-mentioned broadcasting Techniques are known that have made it possible to record entire programs.

For example, in the case of a VH5 VTR based on the NTSC system, if the required recording time is 150 minutes for a magnetic tape with a tape recordable time of 120 minutes in SP mode, recording will be performed in SP mode for the first 105 minutes. For the remaining 45 minutes, recording is performed in the EP mode (the tape speed is 18 times that in the SP mode, also referred to as the 3x mode). VH8 using PAL system
In the case of VTRs using the SP mode, the tape speed in the long time mode is 18 times that of the SP mode, and is called the LP mode (or 2x mode).
Recording is performed in the LP mode for the remaining 60 minutes.

In addition, in conventional VTRs, in addition to the normal playback mode in which the magnetic tape is played back by running it at the same speed as when it was recorded, there is also a playback mode in which the magnetic tape is run at a higher speed than in the normal playback mode for high-speed playback. There is also a function that allows you to shorten the playback time for a certain length of magnetic tape, allowing you to quickly locate the beginning or search for a desired recorded portion. There is.

[The problem that the invention aims to solve] By the way, when recording in EP mode or LP mode, SP
Compared to the case of recording in this mode, the width of the track on the magnetic tape becomes narrower, and the S/N of the reproduced video signal decreases, resulting in deterioration of the image quality of the reproduced image. Therefore, as mentioned above, when recording is performed in combination with SP mode and EP or LP mode, the tape recordable time is expanded, but on the other hand, the playback image from the portion recorded in EP or LP mode is There was a problem that the image quality deteriorated.

Furthermore, the high-speed playback modes in conventional VTRs are limited to a double-speed playback mode in which the tape speed is twice that in the normal playback mode, and a fast-forward search mode in which the tape speed is sufficiently faster than in the normal playback mode. In the high-speed playback mode, the quality of the reproduced image deteriorates significantly compared to the normal playback mode.

Moreover, the sound cannot be played in fast forward search mode, and although the sound is played in double speed playback mode, the changes are too fast and the pitch is high, making it extremely difficult to understand the content. It turns out.

SUMMARY OF THE INVENTION An object of the present invention is to provide a magnetic recording and reproducing apparatus that solves this problem and can extend the tape recordable time while ensuring the quality of reproduced images.

Another object of the present invention is to provide a magnetic recording and reproducing apparatus that can reproduce the tape at any tape speed faster than in normal reproduction mode, while ensuring the image quality of reproduced images and without significantly deteriorating the quality of reproduced audio. Our goal is to provide the following.

[Means for Solving the Problems] In order to achieve the above object, the present invention firstly reduces the running speed of the magnetic tape by running the magnetic tape at low speed and rotating the magnetic head at low speed during recording. The video signal to be recorded is thinned out at a ratio corresponding to the ratio of , and the time axis is expanded by this thinning amount.

Second, during reproduction, the magnetic tape is run at high speed and the magnetic head is rotated at high speed, and the video signal reproduced from the magnetic tape is adjusted at a ratio corresponding to the rate of increase in the running speed of the magnetic tape. Thin out and further extend the time axis.

[Function] The present invention improves the running speed of the magnetic tape during recording compared to the conventional VT.
By lowering the R speed compared to when recording (normal recording), the tape recordable time is extended, but at the same time, the rotation speed of the magnetic head is also lowered, which reduces the width of the track formed on the magnetic tape. , pitch, inclination, and other track formats are the same as when the running speed of the magnetic tape is not reduced. Moreover, since the video signal to be recorded is thinned out at a rate corresponding to the rate of decrease in the running speed of the magnetic tape, and the time axis is expanded by the thinning, each track formed on the magnetic tape is The same length of video signal will be recorded as without the speed reduction.

As a result, even if the magnetic tape is run at the same speed as when recording on a conventional VTR and the magnetic head is rotated for playback, the magnetic head will correctly scan each track on the magnetic tape and set the correct time. The video signal of the axis is played back, and the playback image using the video signal is stable and good, which is longer than the tape recordable time when the magnetic tape is run at the same speed as when recording with a conventional VTR. What you get is image quality.

Furthermore, during reproduction, the reproduction time is shortened by increasing the running speed of the magnetic tape compared to the normal reproduction mode, but at the same time, by increasing the rotational speed of the magnetic head, the magnetic tape is The head sequentially and correctly scans the tracks of the magnetic tape for reproduction. The video signal played back by this is compressed in time because the relative speed between the magnetic tape and the magnetic head is higher than during normal playback, but The video signal is thinned out according to the ratio and the time axis is expanded by the amount of the thinning, resulting in a video signal with the correct time axis.

As a result, the reproduced image is stabilized and has high image quality.

[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 the magnetic recording/reproducing apparatus according to the present invention, in which 1 to 4 are input terminals, 5 is a Y/C
(brightness/chroma) separation circuit, 6°7 is a switch, 8 is an input terminal, 9 is a TBC (time base correction circuit), 10.11 is a sync separation circuit, 12 is a brightness signal processing circuit, 13 is a DC (
14 is a frequency modulation circuit (hereinafter referred to as FM modulation circuit), 15 is a demodulation circuit, and 16 is a TB
C117 is a modulation circuit, 18.19 is O8C (oscillation circuit)
, 2o is an audio signal processing circuit, 21 is a pitch shift circuit,
22 is an FM modulation circuit, 23 is a mixing/amplifying circuit, 24 is a servo/tape system, 25 is a magnetic tape, 26.27 is a magnetic head, 28 is a tack sensor, 29 is a cylinder motor,
30 is a capstan motor, 31 is a servo circuit, 32 is a frequency dividing circuit, 33 is an OSC134, and 35 is an input terminal.

In the figure, in the recording mode, the servo/tape system 24 receives a recording instruction signal RFC from the input terminal 34.
is input, and the servo circuit 31 starts operating. Further, 08C33 generates a reference clock RCLK. This reference clock RCLK is supplied to the servo circuit 31 and divided by the frequency dividing circuit 32, and is a vertical synchronization pulse synchronized with the vertical synchronization signal of the color video signal input from input terminals 1, 3 or input terminal 2. VDR is generated and supplied to the servo circuit 31.

The servo circuit 31 generates a control signal CERR using a signal CFG with a frequency proportional to the rotational speed of the capstan motor 30 based on the reference clock RCLK and the vertical synchronization pulse VDR.
o is controlled to keep the running speed of the magnetic tape 25 constant, and the cylinder motor 2 from the tack sensor 28
A control signal DERR is generated using a tack signal TP representing the rotational phase of 9 and a signal DFG having a frequency proportional to the rotational speed of the cylinder motor 29, thereby controlling the cylinder motor 29 to rotate the magnetic head 26, 27. phase,
Control the rotation speed.

On the other hand, when the input color video signal is a component signal, the switch 6.7 is closed to the A contact side by the switching control signal from the input terminal 8, and the brightness signal Y is input from the input terminal 1, and the switch 6. The chroma signal C is input from the input terminal 3 to the switch 7.
is supplied to the A contact of the Further, when the input color video signal is a composite signal, the switches 6 and 7 are closed to the B side, and this color video signal is input from the input terminal 2, and the Y/C separation circuit 5 separates the luminance signal Y and the chroma signal. The luminance signal Y is supplied to the B contact of the switch 6, and the chroma signal C is supplied to the B contact of the switch 7. Therefore, in any case, the switch 6 outputs the luminance signal Y, and the switch 7 outputs the chroma signal C.

The luminance signal Y from the switch 6 is supplied to the TBC 9 and the sync separation circuit 10, and the sync separation circuit 10 outputs the horizontal sync signal H.
8I is separated. At TBC9.

The horizontal synchronization signal HSI from the synchronization separation circuit 10 and the servo/
Using the reference clock RCLK and the vertical synchronizing pulses VD and l generated by the tape system 24, thinning of the luminance signal and time axis expansion processing are performed at a ratio corresponding to the expansion rate of the tape recordable time of the magnetic tape 25. . When extending the tape recordable time, the oscillation frequency of the 08C33 is reduced by the proportion of this extension in response to an instruction signal from the input terminal 35. Correspondingly, the frequencies of the reference clock RCLK and the vertical synchronization pulse VDR are reduced, the rotational speeds of the capstan motor 30 and cylinder motor 29 are reduced, and the running speed of the magnetic tape 25 and the rotational speed of the magnetic heads 26 and 27 are reduced. For example, this is lower than when recording a track pattern defined by the VH5 standard on the magnetic tape 25 (hereinafter, this recording is referred to as normal recording). This reduction in tape speed extends the tape recordable time, but the rotational speed of the magnetic heads 26 and 27 is also reduced to the same extent as the tape running speed, so that tape recording is possible on the magnetic tape 25. A track pattern with the same format as when no time expansion is performed (that is, during normal recording) is obtained.

Incidentally, the rotation period of the magnetic heads 26 and 27 is generally set to the length of one frame period of the video signal, so that one field is recorded on each track on the magnetic tape 25. However, as mentioned above, the magnetic head 26.2
When the rotational speed of 7 is reduced, the time required for each magnetic head 26, 27 to form one track increases by the proportion of the tape recordable time, and becomes longer than the length of one field of the video signal. Furthermore, the relative speed between the magnetic tape 25 and the magnetic heads 26 and 27 also decreases, and the recordable band becomes narrower.

TBC9 thins out the luminance signal Y at a rate according to the expansion rate of the tape recordable time by using the reference clock RCLK and the vertical synchronization pulse Vow whose frequency is reduced according to the expansion rate of the tape recordable time. A time axis expansion process is performed, and the magnetic head 26.
The duration of one field of the luminance signal recorded in the time required for 27 to form one track is made equal, and one field is recorded on each track. , FM modulated) is made to fall within the recordable band on the magnetic tape 25.

Here, the TBC 9 and its operation will be explained with reference to FIGS. 2 and 3. However, FIG. 2 is a block diagram showing the configuration of the TBC 9, and 36 is an A/D (analog/
digital) conversion circuit, 37 is memory, 38 is D/A
(digital/analog) conversion circuit, 39 is PLL (
40 is a memory control circuit.

In the figure, the PLL circuit 39 is connected to the synchronization separation circuit 10 (
A horizontal synchronizing signal H8I is supplied from the horizontal synchronizing signal H5I (Fig. 1), a write clock WCLK synchronized with this horizontal synchronizing signal H5I, and a vertical synchronizing pulse V o w synchronized with the vertical synchronizing signal of the luminance signal Y from the switch 6 (Fig. 1) and generate. The memory control circuit 40 generates a write reset pulse W* from the write clock WCLK and the vertical synchronization pulse Vow.
*t and a read reset pulse R11I#.

The brightness signal Y from the switch 6 is an A/
It is digitized by the D conversion circuit 36 and supplied to the memory 37. Memory 37 is a field (or frame)
It has a storage capacity that is an integral multiple of WC, and the write clock WC
The digitized luminance signals from the A/D conversion circuit 36 are stored in the order of addresses specified by the output of a write address counter (not shown) that counts LK. The write reset pulse WR, has a period of fields (or frames) equal to the storage capacity of the memory 37, and resets the write address counter. therefore,
In the memory 37, when the digitized luminance signal corresponding to the storage capacity is written, the write address counter is reset by the write reset pulse W, . . . and writing is performed again from the first address.

On the other hand, the memory 37 is supplied with the reference clock RCLK from the 08C33 (FIG. 1) as a read clock.
Also, from the frequency dividing circuit 32 (FIG. 1), a vertical synchronizing pulse VD
R is supplied. This read clock RCLK is counted by a read address counter (not shown), and the digital luminance signals written in the address order specified by the output are read from the memory 37. The vertical synchronizing pulse vDR is used to determine the timing for reading out the vertical synchronizing signal in the digitized luminance signal from the memory 37. For example, each time this vertical synchronizing pulse VD,l is supplied, the read address counter is activated. It is preset to specify the recording address of the vertical synchronization signal in the memory 37.

As a result, the vertical synchronization signal of the digitized luminance signal output from the memory 37 is the vertical synchronization pulse VDII.
phase synchronize with.

The digitized luminance signal read out from the memory 37 is D
The signal is supplied to the /A conversion circuit 38 and converted into an analog signal using the reference clock RCLK. This analog luminance signal Y'
is supplied to the luminance signal processing circuit 12 in FIG.

The read reset pulse RR,t output from the memory control circuit 40 has the same period as the write reset pulse W we w t and has a phase difference with respect to the write reset pulse Welt, and resets the read address counter mentioned above. . As a result, in the memory 37, reading starts from the first address with a delay of this phase from writing.

In the case of normal recording in which no instruction signal is input from the input terminal 35 in FIG. 1 and the tape recordable time is not extended, the period of the reference clock RCLK is
The period of the vertical synchronizing pulse VDR is equal to the period of the vertical synchronizing pulse V o , /. therefore,
In this case, all the digitized luminance signals written in the memory 37 are read out on the same time axis.

When extending the tape recordable time, the period of the reference clock RCLK becomes longer than the period of the write clock VCLK, and the period of the vertical synchronization pulse VDR also becomes longer than the period of the vertical synchronization pulse VD, /. For this reason, the digital luminance signal read from the memory 37 is time-axis expanded with respect to the digital luminance signal written to the memory 37, and therefore the luminance signal Y' obtained from the D/A conversion circuit 38 is A/D conversion circuit 36
This means that the time axis has been expanded with respect to the luminance signal Y supplied to the luminance signal Y. Moreover, the period of the read reset pulse RRmt output from the memory control circuit 4o is the same as the write reset pulse W. Since it is constant and equal to the period of t, the read address counter is reset by the read reset pulse R1t before all the digital luminance signals written from the memory 37 by the reference clock RCLK and the vertical synchronization pulse VOR are read out, Reading returns to the first address. For this reason, some portions of the memory 37 are not read out, and thinning is performed accordingly.

Therefore, let us assume that the period of the write clock WCLK is t, the period of the reference clock RCLK is αt (however, α>1), and the write reset pulse W is generated. If the data amount of the digital luminance signal written to the memory 37 in one cycle of t is Q, then the data amount of the digital luminance signal written in the memory 37 in one cycle of the read reset pulse RR□ is
The data amount Q' of the digital luminance signal read from is Q' = Q X t / a t = Q / a
Therefore, α-1 ΔQ=Q-Q'=-XQ α data amount is thinned out without being read.

Here, the data amount ΔQ to be thinned out is an integral multiple of the data amount for one field (or one frame).

Next, using FIG. 3, the required recording time is 150 minutes for a magnetic tape with a tape recordable time of 120 minutes as described above.
The operation of the TBC 9 in FIG. 2 when the time is 10 minutes will be explained. Note that FIG. 3(a) shows successive fields (or frames) of the digital luminance signal written into the memory 37, and TF is the time length of the field (or frame).

Further, FIG. 3(b) shows successive fields (or frames) of the digital luminance signal read out from the memory 37, and TF' is the time length of the field (or frame).

In this case, the tape recordable time is 150/120=
It needs to be expanded 5/4 times. Therefore, a digital luminance signal is written into the memory 37 by the reset pulse W. 1 of t
Assuming that 10 fields (or 10 frames) are written in a cycle, as shown in Figure 3, 8 fields (or 8 frames) of digitized luminance signals are written every 10 fields (or 10 frames). The brightness signal is read out with a period length of 10 fields (or 10 frames). In this way, the time length TF' of one field (or l frame) of the digital luminance signal read out from the memory 37 is 574 times the time length TF of one field (or l frame) of the digital luminance signal written in the memory 37. is expanded to.

In FIG. 1, the luminance signal Y' obtained by the processing in the TBC 9 as described above is supplied to the luminance signal processing circuit 12, and the DC level is set to a predetermined level by the DC level shift circuit 13, and the FM modulation circuit FM modulated at 14,
The signal is supplied to a mixing/amplifying circuit 23. The DC level shift circuit M13 consists of a clamp circuit, and the input terminal 35
The clamp level is changed according to the command signal (that is, according to the rate of expansion of the tape recordable time). This prevents the recording wavelength on the magnetic tape 25 from changing even if the relative speed between the magnetic tape 25 and the magnetic head 26, 27 changes in order to extend the tape recordable time. This will be explained using FIG.

FIG. 4 is a diagram showing the characteristics of the FM modulation circuit 14 in FIG. 1.

In the figure, a solid line a indicates the modulation characteristics of this FM modulation circuit 14. Now, when the amplitude of the input signal is 2V2 and the center level is vo, in the output signal, the frequency with respect to the center level v0 of the input signal is fo and the frequency deviation is d e
Suppose it is V1. Therefore.

When the relative speed between the magnetic tape and the magnetic head is reduced in order to extend the tape recordable time, the wavelength of the signal recorded on the magnetic tape becomes shorter than when the relative speed is not reduced.

By the way, the reason why the running speed of the magnetic tape 25 and the rotational speed of the rotary heads 26 and 27 are reduced as described above is that the track pattern formed on the magnetic tape 25 is different from the track pattern without these reductions. This is to make it possible to extend the tape recordable time by making them match, and when playing back the magnetic tape 25, in the case of normal playback, the running speed of the magnetic tape 25 and the rotational speed of the magnetic heads 26 and 27 are as follows. It is set equal to that during normal recording, and therefore higher than during recording.

Therefore, when normally playing back the magnetic tape 25 on which recording has been performed with the tape recordable time extended as described above,
When the recording wavelength becomes shorter as described above, the frequency of the reproduced signal becomes higher. In other words, this is equivalent to recording with an increased frequency of the recording signal. Therefore, the modulation characteristic of the FM modulation circuit 14 is changed from the solid line a to the broken line A, and the output signal is equal to that of the input signal. This is equivalent to the frequency with respect to the center level v0 being raised higher than f, l and f.

Even if the modulation characteristics of the FM modulation circuit 14 equivalently change in this way, the DC level shift circuit 13 in FIG.
The frequency of the output signal with respect to the center level v0 of the input signal does not change and can be fixed at fo. For this reason, when the modulation characteristic changes equivalently as shown by the broken line in FIG. 4, the center level of the input signal is set to .

The output frequency is decreased from {circle over (2)} to {circle around (1)} and eight (8) so that the output frequency with respect to this central level {circle around (1)} becomes fo.

Regarding the frequency deviation, since the modulation characteristic is linear, there is no need to change the amplitude of the input signal.

Next, chroma signal processing will be explained.

The chroma signal C output from the switch 7 is sent to the demodulation circuit 15.
and two baseband color difference signals R-Y using the color subcarrier from 08C18.

It is demodulated into B-Y. These color difference signals R-Y and B-Y are supplied to the TBC 16, and similarly to the TBC 9, they are each thinned out 7
The time axis is expanded. The two color difference signals R-Y and B-Y output from the TBC 16 are supplied to the modulation circuit 17,
Quadrature two-phase balanced modulation is performed on the color subcarrier from 08CI9.

Here, the luminance signal Y' output from the TBC 9 is supplied to the synchronization separation circuit 11, and its horizontal synchronization signal H82 is separated. For example, an NTSC VH8 VTR
In this case, ○5C19 generates the color subcarrier at a frequency approximately 40 times its frequency f, l (ie, approximately 40f,') from this horizontal synchronizing signal H82. As a result, the modulation circuit 17 outputs an FM-modulated luminance signal (hereinafter referred to as an FM luminance signal) output from the luminance signal processing circuit 12.
A chroma signal (hereinafter referred to as a low frequency converted chroma signal) CL in a frequency band lower than the frequency band of YFI-1 is obtained. This low frequency converted chroma signal OL is supplied to the mixing/recording circuit 23.
supplied to

Although not shown, the color burst signal of the chroma signal C from the switch 7 is supplied to the ○5C18, and the color subcarrier is generated in phase synchronization with this color burst signal.

Audio signal A input from input terminal 4 is supplied to audio signal processing circuit 20 . In this audio signal processing circuit 2o,
The audio signal A is transferred to the magnetic tape 25 by the pitch shift circuit 21.
After the pitch is shifted according to the rate of expansion of the recordable time of the tape, the FM modulation circuit 22 performs FM modulation. As mentioned above, the pitch shift circuit 21 is provided to alleviate the difficulty in hearing the reproduced audio due to the tape speed during reproduction and the rotational speed of the magnetic head 26, 27 being set higher than during recording. The frequency of the audio signal A is lowered by pitch shifting. This pitch shift is performed, for example, by thinning out the audio signal A at a period corresponding to the rate of expansion of the tape recordable time without changing the audio signal A on the time axis.

The FM-modulated audio signal (hereinafter referred to as FM audio signal) AFM output from the audio signal processing circuit 20 has a frequency band of an FM luminance signal YFM and a low frequency converted chroma signal O.
After being mixed and amplified with the FM luminance signal YFM and the low frequency conversion chroma signal CL in the mixing/amplifying circuit 23, the magnetic head 26.27
is supplied to the magnetic tape 25 and recorded on the magnetic tape 25.

Here, if the tape recordable time of the magnetic tape 25 is 120 minutes and the required recording time is 150 minutes as described above,
Since the tape recordable time has to be extended by 574 times, the running speed of the magnetic tape 25 is reduced to 415 times the normal speed, and accordingly, the same track pattern as during normal recording is formed on the magnetic tape 25. In order to achieve this, the time required for the magnetic heads 26 and 27 to form one trunk on the magnetic tape 25 is made 5/4 times the time required for normal recording. When extending the tape recordable time in this way,
As mentioned above, from TBC9, 16, FM luminance signal YF
The length of one field of M and the low frequency converted chroma signal CL is 5/4 times the length of one field of the input luminance signal Y and the input chroma signal C. Therefore, the magnetic tape 25
On each track formed above, one field of the FM luminance signal YFM and the low frequency converted chroma signal CL are recorded.

Also, the track pattern on the magnetic tape 25 is the same as during normal recording, but the video signal of a 150-minute broadcast program is divided into 2 fields (or 2 frames) every 10 fields (or 10 frames) as described above. Since the number of fields (or frames) of this video signal is equal to the number of fields (frames) of a video signal for 60 minutes,
A 0 minute video signal will be recorded on the magnetic tape 25 from beginning to end.

As described above, it is possible to extend the tape recordable time, and in this case, the tape format is not impaired, and the frequency of the video signal and audio signal is not affected by the recording speed, making it compatible with other VTRs. The image quality of the reproduced image and the sound quality of the reproduced audio can be maintained well.

FIG. 5 is a block diagram showing another embodiment of the magnetic recording and reproducing apparatus according to the present invention, in which 41 is an ACC (automatic chroma control) circuit, 42 is a frequency conversion circuit, 43 is an LPF (low pass filter), and 44 is a This is a TBC, and parts corresponding to those in FIG. 1 are given the same reference numerals and redundant explanations will be omitted.

This embodiment differs from the embodiment shown in FIG. 1 only in the processing of the chroma signal.

In FIG. 5, the chroma signal C output from the switch 7 is amplified by the ACC circuit 41 so that the color burst signal has a constant amplitude, and then supplied to the frequency conversion circuit 42. In the frequency conversion circuit 42, the frequency of the chroma signal C is converted to the lower frequency side, for example, V according to the NTSC system.
For H8 system VTRs, the color subcarrier frequency is set to switch 6.
A low frequency converted chroma signal having a frequency approximately 40 times higher than the horizontal synchronization frequency of the luminance signal Y outputted from the chroma signal Y is generated. After unnecessary components are removed from this low-frequency converted chroma signal by LPF43,
It is supplied to TBC44.

The TBC 44 is a TBC 44 as described in FIGS.
It performs the same operation as BC9, thins out the low-frequency conversion chroma signal supplied at the same ratio as TBC9, and performs time axis expansion processing, approximately 40 times the horizontal synchronization frequency of the luminance signal Y' output from TBC9 ( In the case of a VH8 system VTR using the NTSC system), the low-pass conversion chroma signal Ct of the color subcarrier frequency.

generate. This low-frequency converted chroma signal CL is mixed with the FM luminance signal YFM and the FM audio signal AFM in the mixing/amplifying circuit 23, amplified, and then supplied to the servo tape system 24, as in the embodiment shown in FIG. recorded.

As described above, in this embodiment, with regard to chroma signal processing, it is sufficient to simply add a TBC to the chroma signal processing circuit of a conventional VTR, and the same effects as the embodiment shown in FIG. 1 can be obtained.

In addition, Fig. 1 and Fig. 5 fi! explained above in 9. In the embodiment of if, the TBC 9 is provided before the luminance signal processing circuit 12, but it may be provided after the luminance signal processing circuit 12. However, in this case, in the FM modulation circuit 14, the center level of the luminance signal Y is
As with conventional VTRs, the DC level shift circuit 13 is not required because it is fixed to vo in FIG. 4, but this FM
Since the frequency of the FM luminance signal supplied from the modulation circuit 14 to the TBC 9 is higher than the frequency of the luminance signal Y, the TB
In the C9, the frequencies of the write clock WCLK and read clock RCLK (Figure 2) must be made high, and the memory 37 (Figure 2) of the TBC9 must have a large storage capacity. .

Further, these embodiments are not limited to the VH8 system VTR based on the NTSC system, and may be applied to VTRs of other systems or 8 mm video.

Furthermore, audio signals recorded by a fixed head in the longitudinal direction of the magnetic tape may be similarly pitch-shifted and recorded.

Furthermore, in FIGS. 1 and 5, the FM luminance signal Y
A signal representing the thinned out position may be added to the FM.

FIG. 6 is a block diagram showing still another embodiment of the magnetic recording and reproducing apparatus according to the present invention, in which 45 is a reproducing amplifier circuit;
46 is a Y/C separation circuit, 47 is a luminance signal processing circuit, 48
is a frequency demodulation circuit (hereinafter referred to as F Mtllrl1 time N), 49 is a H decay 11r, 50 is a synchronous separation circuit, 51 is a TBC152 is a demodulation circuit, 53 is a TBC15
4 is a modulation circuit, 55 and 56 are ○5C557 is a frequency division circuit,
58 is a mixing circuit, 59 to 61 are output terminals, 62 is an audio signal processing circuit, 63 is an FM demodulation circuit, 64 is a pitch shift circuit, 65 is an output terminal, and parts corresponding to those in FIG. 1 are given the same reference numerals. I'm wearing it.

This embodiment makes it possible to prevent deterioration in the image quality of the reproduced image and the sound quality of the reproduced audio when the magnetic tape is reproduced at a higher running speed than in the normal reproduction mode and the reproduction time is shortened. It is.

Similar to the magnetic tape used in conventional VTRs, the magnetic tape used here records a mixed signal of an FMII degree signal, a low-frequency conversion chroma signal, and an FM audio signal in one field per track. ing.

In FIG. 5, when a reproduction command signal is input from the input terminal 34, the servo tape system 24 starts the reproduction operation,
Start playing the above magnetic tape (not shown). Also,
When no instruction signal is input from the input terminal 35, the running speed of the magnetic tape and the rotational speed of the magnetic head (not shown) are the same as in the normal playback mode of a VH5 system VTR based on the NTSC system, and normal playback is not performed. However, when shortening the playback time, an instruction signal representing the rate of reduction is inputted from the input terminal 35, and the running speed of the magnetic tape and the rotational speed of the magnetic head are increased in proportion to this rate. , the relative speed between the magnetic tape and the magnetic head is increased. As a result, the magnetic head sequentially scans the tracks on the magnetic tape for reproduction.

The reproduction signal obtained from the magnetic tape in this way is amplified by a reproduction amplification circuit 45, and then supplied to a Y/C separation circuit 46, where it is separated into an FM luminance signal YFM and a low frequency converted chroma signal CL. be done.

This FM luminance signal YFM is supplied to the luminance signal processing circuit 4''7. In the luminance signal processing circuit 47, the FM luminance signal YPM is first demodulated by the FM demodulation circuit 48 to become a baseband luminance signal, and then, Processed by an attenuation circuit 49.

Here, the function of the attenuation circuit 49 will be explained.

In order to shorten playback time, the running speed of the magnetic tape and the rotational speed of the magnetic head are adjusted to the normal playback mode (as described above).
1+α) times (however, α≧0, α>0 when the playback time is shortened, and α=0 when the playback time is normal).
The playback time at this time is shortened to 1/(1+α) times that of normal playback.

By the way, the demodulation characteristic of the FMfji@ circuit 48 is shown by the solid line a in FIG. 7, and when the FM luminance signal YFM in the normal reproduction mode (α=0) is demodulated, its center frequency f,
For the frequency deviation d eV2, the center level is v3. Assuming that a luminance signal with an amplitude range of v4 is obtained, when the playback time is shortened to 1/(1+α) times the normal playback mode as described above, the relative speed between the magnetic tape and the magnetic head is set to the normal playback mode. The center frequency of the reproduced FM luminance signal YFM is (1+α) f2 because it is (1+α) times as high as that in the mode.
, the frequency deviation is (1+α)deV2. For this reason, the demodulated output of this FM luminance signal YFM has a center level of (1+α)■1 and an amplitude range of (1+α)■1, as shown in FIG.
＋α）■, yell.

The fact that the center level of the demodulated luminance signal is (1+α) times higher than in normal playback mode means that the DC level has simply increased, so by removing the DC component with a coupling capacitor, it becomes a special problem. However, the amplitude range expanded by a factor of (1+α) must be corrected in the same way. For this correction, an attenuation circuit 49 is used in the luminance signal processing circuit 47 of FIG. The amount of attenuation of the attenuation circuit 49 is changed at a ratio according to the percentage reduction of the reproduction time, and when the reproduction time is shortened to 17 (1+α) times of the normal reproduction mode, the attenuation circuit 49 changes the input luminance signal to 17 It is attenuated by (1+α) times. As a result, the amplitude range of the 8-power luminance signal Y' of the luminance signal processing circuit 47 obtained from the attenuation circuit 49 becomes the same as in the normal reproduction mode.

This luminance signal Y' is supplied to the synchronization separation circuit 50 to separate the horizontal synchronization signal H83, and is also supplied to the TBC 51. TBC51 is the TBC of Fig. 1 shown in Fig. 2.
9, the horizontal synchronization signal H53 from the synchronization separation circuit 50, and the reference clock RCLK from ○5C56.
By using ' and the vertical synchronizing pulse VDR from the frequency dividing circuit 57, the input luminance signal Y' is thinned out and the time axis is expanded at a ratio corresponding to the reduction rate of the reproduction time.

This TBC 51 will be explained with reference to FIG. 2 (however.

The horizontal synchronization signal H53 from the synchronization separation circuit 50 is supplied to the PLL circuit 39, and the write clock W
CLK' and a vertical synchronization pulse Vr)w are generated. The period of this vertical synchronizing pulse VDW' is equal to the field period (or frame period) of the luminance signal Y' supplied to the TBC 51.

The memory control circuit 40 uses this vertical synchronization pulse V rr w
A write reset pulse W11. whose cycle is an integral multiple of the cycle of W11.
Generate read reset pulses R,,t'. Reference clock RCL from 08C56 as write clock
K' is a constant period, and vertical synchronization pulse VD*'
is obtained by dividing the reference clock RCLK' by the frequency dividing circuit 57, and is equal to the field period (or frame period) of the standard video signal.In the case of normal playback, the write clock WCLK' and the reference clock RCL
K' vertical synchronizing pulse VD,/ and V o *' have the same period, but when the relative speed between the magnetic head and the magnetic tape is increased to shorten the playback time, the input luminance signal Y' supplied to the TBC 51 is compressed on the time axis, and its field period and horizontal synchronization period are shorter than in normal playback mode at a ratio corresponding to the reduction rate. However, since the ratio of the period of the write clock WCL K' and the period of the vertical synchronization pulse V D %/ + write reset pulse w,, t' is always constant, the number of fields of the luminance signal Y' written in the memory 37 is (or the number of frames) is also constant.

Therefore, we are now converting the part that takes time T in normal playback to 4
In this case, the time axis will be shortened by 15 times.
If the above α is 1/4) and the storage capacity of the memory 37 is 10 fields, then the field period T of the input luminance signal Y'
F” is the field period of the standard video signal.
Then, 1 4 TF"=1+(E"=5". Therefore, the period of the reference clock RCLK'vertical synchronization pulse VDR' is the write clock WCLK'
, vertical synchronization pulse X V tlw ' (7) 5 /
4 times the reference clock RC, as shown in FIG.
LK' and vertical synchronization pulse V o *',
The luminance signal Y' is read out from the memory 37 in 8 fields every 10 fields, and each field has 57 fields.
The time axis has been expanded four times. As a result, TBC51
Each field period of the luminance signal Y outputted from the luminance signal Y' is time-axis expanded by 5/4 times to become TF, and becomes a standard luminance signal.

The above has been the processing of the luminance signal, but next, the processing of the chroma signal will be explained.

Low frequency converted chroma signal CL obtained by Y/C separation circuit 46
is supplied to the demodulation circuit 52, which uses the color subcarrier from 03C55 to generate two baseband color difference signals R-Y, B-
Yl: Demodulated. Although not shown, the oSC 55 is controlled by a color burst signal separated from the low frequency converted chroma signal OL using the horizontal synchronization signal H83 from the synchronization separation circuit 50 as a reference, and the oSC 55 outputs a color whose frequency 2 phase is synchronized with this color burst signal. Generate subcarrier.

The two color difference signals obtained by the demodulation circuit 52 are sent to the TBC 53.
In the same way as the TBC 51, it is subjected to 1 decimation and time axis expansion processing, and the modulator 54 performs quadrature two-phase balanced modulation on the color printing carrier wave from the 05C56 to obtain a standard chroma signal C.

The luminance signal Y output from the TBC 51 and the chroma signal C output from the modulation circuit 54 are output from output terminals 59 and 61 as component signals, respectively.
On the other hand, the signals are mixed by the mixing circuit 58 and outputted from the output terminal 60 as a composite signal.

The reproduction signal amplified by the reproduction amplification circuit 45 is also supplied to an audio signal processing circuit 62 to separate the FM audio signal, and supplied to an FM demodulation circuit 63 where it is demodulated into a baseband audio signal. When the relative speed between the magnetic tape and the magnetic head is increased to shorten the playback time, this audio signal is also processed at a ratio (1/1) corresponding to the shortening rate.
The time axis has been compressed (1+α) times. Therefore, this audio signal is supplied to the pitch shift circuit 64, and is pitch-shifted at a rate corresponding to the rate of reduction in playback time.

The audio signal A processed in this way is sent to the output terminal 65.
As described above, in this embodiment, the time required to play one track is 17 (1+α) times shorter than in the normal playback mode, so the playback time is shortened to 1/(1+α) times. Moreover, by increasing the running speed of the magnetic tape and the rotational speed of the magnetic head, the magnetic head can correctly scan the tracks on the magnetic tape, and the reproduced video signal can be thinned out and time-axis expanded. Since the field (or frame) period is made to match that of the standard method, reproduced images whose contents change faster than in normal reproduction mode can be displayed stably and with good quality. In addition, in this case.

If the number of fields (or frames) written to the TBC is N, αN/(1+α) fields (or frames) will be thinned out every N fields (or N frames), but the content of the reproduced image is high-speed. , so the effect of this thinning is not very noticeable.

Furthermore, as the relative speed between the magnetic tape and the magnetic head is increased, the time axis of the reproduced audio signal is also compressed, and the frequency is thereby increased. Since the frequency is lowered without conversion such as expansion or compression, even if the voice is spoken quickly, it can be made less difficult to hear. Moreover, since there is no conversion of the audio signal on the time axis, no time lag occurs between the reproduced image and the reproduced audio.

FIG. 9 is a block diagram showing still another embodiment of the magnetic recording/reproducing apparatus according to the present invention, in which 66 is a TBC, 67 is a frequency conversion circuit, 68 is a VCO (voltage controlled oscillation circuit),
69 is a frequency conversion circuit, 70 is an 0SC571 is a frequency dividing circuit, and 72 is a synchronization separation circuit. Portions corresponding to those in FIG. 6 are denoted by the same reference numerals and redundant explanations will be omitted.

This embodiment differs from the embodiment shown in FIG. 6 with regard to the processing of the reproduced chroma signal.

In FIG. 9, the low frequency conversion chroma signal CL separated by the Y/C separation circuit 46 is supplied to the TBC 66, and the TBC 5
1, and the time axis is expanded. The thinning and time axis expansion processing operations of the TBC66 are performed using the horizontal synchronization signal H83 from the synchronization separation circuit 50, the reference clock RCLK from ○5C70, and this reference clock RCLK.
The vertical synchronizing pulse VD obtained by dividing the frequency by the frequency dividing circuit 71
This is done using R.

The low frequency converted chroma signal outputted from the TBC 66 is supplied to a frequency conversion circuit 67, and is frequency converted into a chroma signal C having a standard color subcarrier frequency fllc by the output signal of the frequency conversion circuit 69. Here, in the case of a VH5 system VTR based on the NTSC system, the color subcarrier frequency fL of the low-pass converted chroma signal output from the TBC66 is TBC5.
It is approximately 40 times the horizontal synchronization frequency f of the luminance signal Y output from L (that is, approximately 40f*). This luminance signal Y is supplied to the synchronization separation circuit 72 and a horizontal synchronization signal H84 is output.
is separated, and in synchronization with this horizontal synchronizing signal H84, vC○
68 generates a signal at a frequency of approximately 40f7. Also, 0
8C70 also generates a color subcarrier of frequency fgc,
This color subcarrier and the output signal of vC068 are supplied to the frequency conversion circuit 69, and the frequency is approximately (f11c+4of,
A signal I) is generated. This signal is transmitted to the frequency conversion circuit 6
7, and the low-pass converted chroma signal with a color subcarrier frequency of about 40f9 is converted into a chroma signal C with a color subcarrier frequency of f, c.

In this embodiment, it is only necessary to add a TBC 66 to the conventional color signal processing circuit as a color signal processing circuit, and the configuration can be simplified compared to the embodiment shown in FIG. 6, and the same effect can be obtained. is obtained.

However, since the frequency of the low-pass converted chroma signal is higher than the frequency of the baseband color difference signal, in TBC66, the 6th
A memory having a slightly larger storage capacity than the TBC 53 in the figure is used.

By the way, in the embodiment explained in FIGS. 6 and 9,
Thinning in the TBC to shorten the playback time was performed on arbitrary fields (or frames) determined by the operation of the TBC, regardless of the movement of the image. However, even if you thin out areas where there is no movement or small movement in the image, or areas where movement is intense or fast,
The effect of this thinning is not noticeable on the playback screen, but if thinning is performed in a slow-moving portion of the image, the image movement will momentarily become jerky at the thinned out portion on the playback screen.

FIG. 10 is a block diagram showing still another embodiment of the magnetic recording/reproducing apparatus according to the present invention which can prevent this problem, 73 is a motion detection circuit, and the parts corresponding to FIG. 6 are the same. Reference signs are added to omit redundant explanations.

In the figure, the baseband luminance signal output from the luminance signal processing circuit 47 is written into the memory of the TBC 57, and is also supplied to the motion detection circuit 73, where it is thinned out by field (or frame) correlation of the luminance signal, etc. An inconspicuous portion is also detected on the screen, and the TBC 51 and 53 are controlled to perform thinning at this portion.

As the motion detection circuit 73, a conventionally known circuit can also be used. The motion detection circuit 73 performs motion detection for a period of a predetermined number of fields (or a predetermined number of frames) of the luminance signal, and based on the detection result, determines the part that will have the least effect even if thinned out, and the TBCs 51 and 53 perform thinning in that part. Let's do it. For this purpose, TBC51,5
3, it is necessary to hold the number of fields (or number of frames) of luminance signals in a unit period in which the motion detection circuit 73 detects motion during the period in which the motion detection circuit 73 detects motion. For example, assuming that the TBCs 51 and 53 perform thinning on a field-by-field basis, if the playback time is to be shortened by 5%, one field must be thinned out every 20 fields, so the motion detection circuit 73 performs motion detection every 20 fields. The TBCs 51 and 53 must have two memories each having a storage capacity of at least 20 fields.

Of course, the motion detection circuit 73 sequentially detects field (or frame) correlations, and when it detects a portion whose effect will hardly appear on the screen even after thinning, it causes the TBC 51 and 53 to perform thinning processing on this portion. You can also do this.

As mentioned above, in this embodiment, FIG.

Compared to the embodiment shown in FIG. 9, this embodiment has the advantage that the effect of thinning on the reproduced image can be further prevented.

Note that in the embodiments shown in FIGS. 1, 5, 6, and 9, thinning is performed in areas that do not affect the image, as in the embodiment shown in FIG. 10. Can be done.

In addition, in FIGS. 6, 9, and 10, TBC
51 may be provided before the luminance signal processing circuit 47. However, in this case, the attenuation circuit 49 is not required, but the storage capacity of the memory in the TBC 51 is
Needless to say, it is necessary to make the circuit 51 larger than that provided at a stage subsequent to the luminance signal processing circuit 47.

Furthermore, in FIGS. 6, 9, and 10, N
VTRs and 8s other than VH8 system VTRs using the TSC system
Needless to say, this method can also be applied to milli-video.

Furthermore, by similarly pitch-shifting the audio signal reproduced from the magnetic tape by the fixed head, it is possible to reduce the difficulty of hearing the reproduced audio.

[Effects of the Invention] As explained above, according to the present invention, it is possible to extend the recordable time on a magnetic tape while ensuring the stability and image quality of reproduced images on a par with conventional SP mode. It is also possible to shorten the playback time.

Furthermore, when extending the recordable time or shortening the playback time, it is possible to reduce the difficulty of listening to the playback audio.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the magnetic recording/reproducing apparatus according to the present invention, FIG. 2 is a block diagram showing a specific example of the time axis correction circuit in FIG. 1, and FIG. 3 is a diagram showing its operation. , FIG. 4 is a diagram showing the characteristics of the frequency modulation circuit and the function of the DC level shift circuit of the luminance signal processing circuit in FIG. 1, and FIG. 5 and FIG. FIG. 7 is a block diagram showing the embodiment; FIG. 7 is a diagram for explaining the operation of the attenuation circuit in the luminance signal processing circuit in FIG. 6; FIG. 8 is a diagram for explaining the operation of the time axis correction circuit in FIG. 9 and 10 are block diagrams showing still other embodiments of the magnetic recording/reproducing apparatus according to the present invention. 9... Time axis correction circuit, 12... Luminance signal processing circuit, 13... DC level shift circuit, 14... Frequency modulation circuit, 15...・・・・・・
Demodulation circuit, 16... Time base correction circuit, 17...
... Modulation circuit, 20 ... Audio signal processing circuit, 21 ... Pitch shift circuit, 22 ...
・Frequency modulation circuit, 24... Servo/tape system, 25... Magnetic tape, 26.27...
・Magnetic head, 31...Servo circuit, 32...
...Frequency divider circuit, 33...Oscillation circuit, 35.
... Input terminal for instruction signal, 42 ... Frequency conversion circuit, 44 ... Time axis correction circuit, 46 ...
... Y/C separation circuit, 47 ... Luminance signal processing circuit, 48 ... Frequency demodulation circuit, 49 ...
... Attenuation circuit, 51 ... Time axis correction circuit,
52... Demodulation circuit, 53... Time axis correction circuit, 54... Modulation circuit, 62...
Audio signal processing circuit, 63... Frequency demodulation circuit,
64...Pitch shift circuit, 66...
Time axis correction circuit, 67... Frequency conversion circuit, 7
3...Motion detection circuit. Figure 2 Figure 3 Figure 4 Figure 7 V Todoroki Figure 8 'TF

Claims (1)

[Claims] 1. Frequency modulation of a luminance signal, converting a chroma signal into a low-frequency converted chroma signal of a frequency band lower than the frequency band of the frequency-modulated luminance signal, and producing the frequency-modulated luminance signal. In a magnetic recording and reproducing device that mixes a signal and the low frequency converted chroma signal and records the mixture on a magnetic tape using a rotating head, the running speed of the magnetic tape is reduced, and at the same time, the speed of the rotating magnetic head is reduced. a first means for reducing the relative speed between the magnetic tape and the rotary head by reducing the rotational speed; and a first means for reducing the relative speed between the magnetic tape and the rotary head; The second time frame is thinned out at a ratio corresponding to
and a third method in which the low frequency converted chroma signal is thinned out with respect to the chroma signal at a ratio corresponding to the rate of reduction in the running speed of the magnetic tape, and the time axis is expanded by the thinned out amount. What is claimed is: 1. A magnetic recording and reproducing apparatus characterized in that the magnetic recording and reproducing apparatus is configured such that the recordable time on the magnetic tape can be extended without changing the tape format. 2. Claim 1, further comprising: fourth means for pitch-shifting the audio signal at a rate corresponding to the rate of reduction in the running speed of the magnetic tape; and a fourth means for frequency modulating the audio signal output from the fourth means. 5, and the frequency-modulated audio signal output from the fifth means is mixed with the frequency-modulated luminance signal and the low-frequency converted chroma signal and recorded on the magnetic tape. A magnetic recording and reproducing device. 3. The magnetic recording and reproducing apparatus according to claim 1 or 2, wherein the second means thins out the luminance signal to extend the time axis, and frequency modulates the output luminance signal of the second means. 4. In claim 3, there is provided a sixth means for reducing the DC level of the output luminance signal of the second means at a rate corresponding to the rate of reduction in the running speed of the magnetic tape, and the sixth means A magnetic recording/reproducing device characterized by frequency modulating an output luminance signal. 5. The magnetic recording and reproducing apparatus according to claim 1 or 2, wherein the second means thins out the frequency-modulated luminance signal and extends the time axis. 6. In claim 1, 2, 3, 4 or 5, the third
The means includes: a seventh means for demodulating the chroma signal into two color difference signals; an eighth means for thinning out each of the color difference signals and expanding the time axis; and two color difference signals output from the eight means. a ninth means for modulating a signal to form the low frequency converted chroma signal. 7. Claim 1, 2, 3, 4, or 5, wherein the third means comprises: tenth means for converting the frequency of the chroma signal to a lower frequency band; and thinning out the output chroma signal of the tenth means. and an eleventh means for extending the time axis. 8. The magnetic recording and reproducing apparatus according to claim 1, 2, 3, 4, 5, 6 or 7, characterized in that a signal indicating a thinning position is added to the luminance signal output from the second means. 9. Claims 1, 2, 3, 4, 5, 6, 7, or 8, further comprising: a motion detection means for detecting the degree of movement of the image from the luminance signal; A magnetic recording/reproducing apparatus characterized in that thinning timings are set by the second and third means. 10. The mixed signal of a frequency-modulated luminance signal and a low-frequency converted chroma signal on the lower frequency band side than the frequency band of the frequency-modulated luminance signal is recorded from the magnetic tape by a rotating head. luminance signal processing means for converting the frequency-modulated luminance signal of the mixed signal into a baseband luminance signal; and chroma signal processing for converting the low-frequency converted chroma signal of the mixed signal into a high-frequency chroma signal. In a magnetic recording and reproducing apparatus, the rotating speed of the magnetic tape is increased, and the rotating speed of the rotary head is increased, so that the rotary head performs reproducing scanning along a track on the magnetic tape that is traveling at high speed. a first means for adjusting the baseband luminance signal to the frequency-modulated luminance signal of the reproduced mixed signal at a ratio corresponding to a rate of increase in the running speed of the magnetic tape; a second means for thinning out and extending the time axis; and increasing the running speed of the magnetic tape with respect to the low frequency converted chroma signal of the reproduced mixed signal. and a third means for thinning the magnetic tape at a ratio corresponding to the ratio of the magnetic tape to extend the time axis, thereby shortening the playback time on the magnetic tape and making it possible to play back the image. Magnetic recording and reproducing device. 11. The magnetic recording and reproducing apparatus according to claim 10, wherein the second means decimates the output luminance signal of the luminance signal processing means and extends the time axis. 12. In claim 11, the luminance signal processing means includes: means for demodulating the frequency-modulated luminance signal of the reproduced mixed signal; 1. A magnetic recording/reproducing device characterized by comprising: means for attenuating at a ratio corresponding to the ratio. 13. In claim 10, the second means is provided before the luminance signal processing means, and thins out the frequency-modulated luminance signal of the reproduced mixed signal and extends the time axis. A magnetic recording and reproducing device. 14. In claim 10, 11, 12 or 13, the chroma signal processing means includes demodulation means for demodulating the low-pass converted chroma signal of the reproduced mixed signal into two color difference signals, and the two color difference signals. modulating means for generating the high-frequency chroma signal by modulating the color subcarrier with a color subcarrier frequency higher than the color subcarrier frequency of the low-frequency converted chroma signal;
The magnetic recording and reproducing apparatus is characterized in that the third means thins out the two color difference signals, subjects the two color difference signals to time-axis expansion processing, and supplies the processed signals to the modulation means. 15. In claim 10, 11, 12 or 13, the third means is provided before the chroma signal processing means, and thins out the low frequency converted chroma signal of the reproduced mixed signal and extends the time axis. A magnetic recording/reproducing device characterized by: 16, Claim 10, 11, 12, 13, 14 or 15
A magnetic recording and reproducing apparatus characterized in that an audio signal is reproduced from the magnetic tape, and the reproduced audio signal is pitch-shifted at a ratio corresponding to a rate of increase in the running speed of the magnetic tape. 17. Claim 10, 11, 12, 13, 14, 15 or 16, further comprising a motion detection means for detecting the degree of image motion from the luminance signal reproduced from the magnetic tape, and the detection result of the motion detection means is provided. A magnetic recording/reproducing apparatus characterized in that the thinning timing of the second and third means is set depending on the timing of the thinning.