JPH0691667B2 - Magnetic recording / reproducing method and magnetic recording / reproducing apparatus - Google Patents

Description

The present invention relates to a magnetic recording / reproducing method and a magnetic recording / reproducing apparatus, and more particularly to a frequency-modulated luminance signal obtained by frequency-modulating a luminance signal and a carrier color signal. And a low frequency conversion color signal obtained by frequency conversion to a low frequency, frequency-division-multiplexed, recorded on a magnetic recording medium, and reproduced.
Reproduction device

(Prior Art) Conventionally, a frequency obtained by frequency-division-multiplexing an FM luminance signal obtained by frequency-modulating (FM) a luminance signal and a low-pass conversion color signal obtained by frequency-converting a carrier color signal into a low range. There is a video tape recorder (VTR) that records a division multiplex signal on a magnetic tape and reproduces it.

4 (a) and 4 (b) are block system diagrams showing the configurations of the recording system and the reproducing system of the above VTR.

In FIG. 4A, a composite video signal which is a signal having a signal band as shown in FIG. 3B is input to the input terminal 1. This composite video signal is supplied to a comb-shaped filter (comb filter) 2, where the luminance signal shown in FIG. 3 (c) is separated, and this luminance signal is further passed through a low pass filter (LPF) 3, pre-filter. The frequency is modulated by the FM modulator 5 via the emphasis circuit 4 into an FM luminance signal, and the mixing circuit 6
Is supplied to.

On the other hand, in the composite video signal input to the input terminal 1, the carrier color signal shown in FIG. 3 (e) is separated by the band pass filter (BPF) 7, and the carrier color signal is frequency-converted into the low frequency band by the frequency converter 8. It is converted into a low frequency conversion color signal and supplied to the mixing circuit 6. The frequency division multiplexed signal output from the mixing circuit 6 is recorded on the magnetic tape 11 by the magnetic head 10 via the recording amplifier 9.

Further, in FIG. 4 (b), the signal recorded on the magnetic tape 11 is reproduced by the magnetic head 10, and the reproduced signal is supplied to the high-pass filter (HPF) 13 via the preamplifier 12, Then, the FM luminance signal is separated, and this FM luminance signal is demodulated by the FM modulator 16 into the original luminance signal via the frequency modulation equalization circuit (FM equalizer circuit) 14 and the limiter 15, and further the LPF 17, It is supplied to the mixing circuit 19 via the de-emphasis circuit 18.

On the other hand, the reproduction signal output from the preamplifier 12 is supplied to the LPF 20, where the low frequency conversion color signal is separated, and the low frequency conversion color signal is fed to the frequency converter & APC (Automatic Phase C
(ontrol) circuit 21 converts the signal into a high frequency band to obtain the original carrier color signal, the time base fluctuation is removed, and the signal is supplied to mixing circuit 19 via BPF 22. The signal output from the mixing circuit 6 is output from the output terminal 23 as a composite video signal.

By the way, in the above-mentioned conventional VTR, the luminance signal band is limited to a narrow band below the color subcarrier frequency (fsc),
As shown in FIG. 3 (a), the band of the luminance signal Y is set so as not to substantially overlap with the band of the carrier color signal C, but recently, the luminance signal band is widened to improve the image quality.
VTR has been developed and commercialized.

In such a high image quality VTR, the band of the luminance signal Y is set to a wide band equal to or higher than the color subcarrier frequency (fsc) as shown in FIG. 3C, and the carrier color signal C shown in FIG. The signal band also includes the band.

Considering the case of recording a high frequency band luminance signal having a wide band vertical correlation with such a high image quality VTR, the composite video signal shown in FIG.
If S is a high-frequency luminance signal and fsc is a color subcarrier frequency, and the luminance signal is separated by a luminance signal comb filter, the high-frequency luminance signal Sy is obtained as the luminance signal system output from the comb filter (first FIG. 5 (b)}.

On the other hand, in the color signal system, since the color signals are separated by the BPF, the high-frequency luminance signal Sc can be obtained in the color signal system as well (FIG. 5 (c)).

High band luminance signal Sy obtained from the comb filter output of this luminance signal system and high band luminance signal S obtained from the BPF of the color signal system.
c is the signal processing circuit for the luminance signal system and the signal processing circuit for the chrominance signal system, which are separately processed and recorded on the magnetic tape. The signals are separately processed and recorded on the tape. The frequency relationship between the high-frequency luminance signals Sy and Sc that are displayed is a signal Sy that is FM-modulated into its side wave and a frequency-converted signal Sc as shown in FIG. 5 (d). Then, this signal Sc interferes with the reproduced FM luminance signal. For example, there have been problems such as this becoming noise and causing an inversion phenomenon.

On the other hand, in the conventional VTR, the luminance signal band is a narrow band, and the luminance signal band is a signal band that does not include the carrier color signal band as described above, and the luminance signal band and the carrier color signal band are Since it was separated, this problem did not occur. In addition, even in the high image quality VTR, when the luminance signal and the color signal are separated from the composite video signal by the comb filter, there is almost no high-frequency luminance signal component in the color signal system, so the above problem does not occur. Absent.

Furthermore, in the conventional VTR, the input signal is only the composite video signal, and the video signal processing circuit is also adapted to it. On the other hand, in addition to the composite video signal, a device in which a luminance signal and a chrominance signal are separately and independently input has been developed in recent years, and by providing a video signal processing circuit corresponding to each input, It is desirable to have the best image quality at each input.

Therefore, the present applicant has proposed a magnetic recording device and a magnetic recording / reproducing device in view of the above-mentioned conventional technique, and was proposed on August 19, 1987.
Filed a patent by date.

FIG. 6 is a block system diagram showing the configuration of the recording system of the apparatus proposed by the present applicant, and FIG. 7 is a block system diagram showing the configuration of the reproducing system.

In the recording system of FIG. 6, the input terminal 31 is shown in FIG.
A composite video signal such as that shown in FIG. 5, that is, a signal in which the carrier color signal C is multiplexed in the higher band of the luminance signal Y is input.

This composite video signal is a comb filter 32
3, the luminance signal Y from which the carrier color signal C component is removed as shown in FIG. 3C is separated, and is supplied to one input terminal a of the switch circuit 33. Further, the luminance signal output from the switch circuit 33 is passed through a low pass filter (LPF) 34 and a pre-emphasis circuit 35, and an FM modulator.
The signal is frequency-modulated by 36 to be an FM luminance signal, which is supplied to the mixing circuit 37.

The luminance signal band is set to a signal band higher than the color subcarrier frequency (fsc) in the wideband mode, for example, approximately 5 MHz, and in the narrowband mode, the color subcarrier frequency (fs
c) The following signal band, for example, approximately 3 MHz is set.

On the other hand, the composite video signal input to the input terminal 31 is supplied to one input terminal a of the switch circuit 39. Further, the signal output from the switch circuit 39 is a carrier color signal as shown in FIG. 3 (e) by the band pass filter (BPF) 40 (however, a predetermined amount of high frequency luminance signal component is contained in this signal. Are separated and supplied to one input end of the mixing circuit 41 via an ACC (Automatic Chroma Control) circuit 42.

A pilot signal, which will be described later, is supplied to the other input terminal of the mixing circuit 41 only in the wide band mode (when the luminance signal band to be recorded is a signal band equal to or higher than the color subcarrier frequency), and is added to the carrier color signal. To be done.

Here, the pilot signal is, for example, fsc = in the case of the PAL system.
This is a burst-shaped signal of about 4.43 MHz, which is added to the period corresponding to the horizontal or vertical blanking period in the carrier color signal.

The carrier color signal output from the mixing circuit 41 is a frequency converter 43.
Is frequency-converted into a low-frequency band and converted into a low-frequency band color signal, which is supplied to the mixing circuit 37 via the killer circuit 44 and the LPF 45. The killer circuit 44 operates when a black and white signal is input from the input terminal 31. The frequency division multiplexed signal output from the mixing circuit 37 is recorded on the magnetic tape 48 by the magnetic head 47 via the recording amplifier 46.

Further, the luminance signal output from the LPF 34 is the sync separation circuit 53.
To the pilot signal generating circuit 54. The horizontal synchronizing signal is separated from the horizontal synchronizing signal and supplied to the pilot signal generating circuit 54. Then, the pilot signal generation circuit 54 generates a pilot signal and supplies it to the mixing circuit 41 via the switch circuit 52.

Further, a luminance signal (Y signal) and a carrier color signal (C signal), which are separated and independent, are input to the input terminals 49 and 50, and these Y signal and C signal are the other input terminals b of the switch circuits 33 and 39, respectively. Is supplied to. The switch circuits 33 and 39 are interlocked and switched by turning on / off the switch S ₁ connected to the system controller 51. When the composite video signal input to the input terminal 31 is recorded, and in the wide band mode having the luminance signal band equal to or higher than the color subcarrier frequency (the switch connected to the system controller 51
To switch the on / off S _2), the switch circuit 3
The movable contact pieces of 3, 39 are switched to the side of the terminal a, and at the same time, the switch circuit 52 is turned on so that the pilot signal is supplied from the pilot signal generation circuit 54 to the mixing circuit 41, and the pilot signal is synchronized with the burst signal. Let that phase
For example, as shown in FIG. 9, -u axis [180 °] (note that
The phase of the burst signal is 180 ° ± 45 °), and when recording the luminance signal and chrominance signal input to the input terminals 49 and 50, and in the wideband mode having the luminance signal band above the color subcarrier frequency, switch The movable contacts of the circuits 33 and 39 are switched to the terminal b side, and at the same time, the switch circuit 52 is turned on,
The phase of the pilot signal is recorded at + u axis [0 °], that is, shifted by 180 ° from the phase of the pilot signal in the above case.

The phase value of the pilot signal is not particularly limited.

In the narrow band mode having a luminance signal band equal to or lower than the color subcarrier frequency, the pilot signal is not recorded.

Next, in the reproducing system shown in FIG. 7, the signal recorded on the magnetic tape 48 is reproduced by the magnetic head 47, and this reproduced signal is passed through the preamplifier 56 and the high pass filter (HPF) 57.
The FM luminance signal is separated, and the FM luminance signal is supplied to the frequency modulation equalizer circuit (FM equalizer circuit) 58.
Is supplied to one input terminal a of the switch circuit 59 via. The output of the preamplifier 56 is also supplied to the HPF60, where the FM luminance signal is separated, and this FM luminance signal is
It is supplied to the other input terminal b of the switch circuit 59 via the FM equalizer circuit 61.

As shown in FIG. 8, the cutoff frequencies of HPF57 and HPF60 are set higher in HPF57 than in HPF60. Also, FM equalizer circuit 58, FM equalizer circuit 6
1 has characteristics suitable for HPF57 and HPF60, respectively. Furthermore, the switch circuit 59 is switched by a switching control signal output from a pilot signal discriminating circuit, which will be described later. For example, when a signal input as a composite video signal recorded in a wide band mode is reproduced, the switch circuit 59 is switched. When the movable contact piece of 59 is switched to the terminal a side and the luminance signal and the chrominance signal input separately and independently are reproduced in the wide band mode, the movable contact piece of the switch circuit 59 is connected to the terminal b. Switch to the side.

Further, the luminance signal output from the switch circuit 59 is demodulated by the FM demodulator 63 into the original luminance signal via the limiter 62, and further, the LPF 61, the de-emphasis circuit 65, the video equalizer circuit 66, the comb filter 67. Is supplied to the mixing circuit 68 via.

On the other hand, the reproduction signal output from the preamplifier 56 is supplied to the LPF 69, where the low-frequency conversion color signal is separated, and the low-frequency conversion color signal is converted to the high frequency by the frequency converter 70 to obtain the original carrier color. The signal is converted into a signal and the time base fluctuation is removed by an APC loop composed of a phase comparator 71, a variable voltage controlled oscillator (VCO) 72, and a crystal oscillator (VXO) 73. Furthermore, a BPF 74, a comb filter 75
Is supplied to the pilot signal cancellation circuit 76 via
Here, when the reproduction color signal is applied with the pilot signal, the pilot signal is canceled (removed). Then, this output signal is sent to the mixing circuit 68 via the killer circuit 77.
Is supplied to. Then, the signal output from the mixing circuit 68 is output from the output terminal 78 as a composite video signal. The comb filter 75 is for removing crosstalk and also for removing high-frequency luminance signal components in the carrier color signal band.

The luminance signal output from the de-emphasis circuit 65 is supplied to the sync separation circuit 80 via the LPF 79, where the horizontal sync signal is separated, and this is separated via the monomulti 81 into the pilot signal discrimination circuit 82 and the pilot signal. It is supplied to the cancel circuit 76.

On the other hand, the reproduction color signal is supplied from the comb filter 75 to the pilot signal discrimination circuit 82, and the pilot signal applied in this reproduction color signal is discriminated at the timing of the gate signal output from the monomulti 81. It And
The pilot signal discrimination circuit 82 detects that the phase of the pilot signal is −
A switching control signal is output depending on whether it is the u-axis [180 °] or + u-axis [0 °], and this is supplied to the switch circuit 59, for example, the signal input as the composite video signal is recorded in the wideband mode. In the case of reproducing the recorded signal, the movable contact of the switch circuit 59 is switched to the side of the terminal a, and in the case of reproducing the separated and independent luminance signal and color signal recorded in the wide band mode, the switch circuit is used. Connect the movable contact of 59 to terminal b.
Switch to the side of. (Note that the phase difference of the pilot signal and the movable segment of the switch circuit 59
The combination of which side to switch to is not limited to this. ) In the above configuration, depending on the presence or absence of a high-frequency luminance signal component in the color signal, for example, when a signal input as a composite video signal recorded in a wideband mode is reproduced, the pilot signal discrimination circuit 82 By discriminating the phase of the pilot signal applied in the reproduced color signal, the switching control signal of the switch circuit 59 from the pilot signal discriminating circuit 82 output in response to this is supplied to the switch circuit 59, and the switch circuit 59 is supplied. The movable contact piece 59 is switched to the terminal a side.

Further, when a luminance signal and a chrominance signal input separately are recorded in a wideband mode and reproduced, the phase of the pilot signal applied in the reproduced chrominance signal is discriminated to determine the pilot signal discrimination circuit. Reference numeral 82 identifies the phase of the pilot signal which differs from the phase at the time of inputting the composite video signal by 180 °, and the switching control signal of the switch circuit 59 from the pilot signal determination circuit 82 output in response to this is the switch circuit 59. And the movable section of the switch circuit 59 is switched to the terminal b side.

As a result, when playing back a signal input as a composite video signal recorded in wideband mode, HPF6
It is lower than HPF57 when reproducing the signal that passed the HPF57 and FM equalizer circuit 58 set to a cut-off frequency higher than 0, and when reproducing the separated independent luminance signal and chrominance signal in wideband mode. The signal passed through the HPF60 and FM equalizer circuit 61 set to the cutoff frequency is reproduced.

Therefore, the luminance signals separated by the HPFs having different cutoff frequencies are reproduced according to the signals recorded as described above (that is, according to the amount of the high-frequency luminance signal component included in the reproduction color signal). Therefore, when the band of the luminance signal Y as shown in FIG. 3 (c) is recorded as a wide band signal band of the color subcarrier frequency fsc or more, there is a problem in reproducing the luminance signal system. It is possible to effectively eliminate the noise due to the beat and the inversion phenomenon due to the high frequency band luminance signal component and the high frequency band luminance signal component included in the carrier color signal.

That is, when the carrier color signal contains a high-frequency luminance signal component of a predetermined amount or more, the HFP with a high cutoff frequency is used,
Low frequency conversion While preventing the influence from high frequency luminance signal components in the carrier color signal, HFP with a low cutoff frequency when the high frequency luminance signal components are not included in the carrier color signal in a specified amount or more.
Thus, the luminance signal is effectively used to contribute to high image quality.

Further, since the FM equalizer circuit 58 and the FM equalizer circuit 61 have characteristics suitable for the HPF57 and HPF60, respectively, an optimum image can be obtained according to the recorded signal.

The HPF preferably uses a filter having a steep characteristic in order to reduce interference as much as possible and widen the band of the luminance signal.

(Problems to be solved by the invention) However, in the above-mentioned device, when a black-and-white signal is input as a signal to be recorded at the time of recording, since the black-and-white signal has no burst signal, a normal killer circuit operates. However, the pilot signal is recorded.

Further, at the time of reproduction, since the pilot signal in the reproduced black and white signal does not have a burst signal for phase comparison, it is not possible to detect the phase with respect to the burst signal. Therefore, the color signal contains a high-frequency luminance signal component. It is not possible to determine whether the case is included or not, and when the pilot signal is erroneously detected, the cutoff frequency of the high-pass filter that separates the reproduction luminance signal fluctuates, and an unstable black and white signal is reproduced. There was a point.

Further, when recording / reproducing a black-and-white signal, the cut-off frequency or the cut-off frequency of the high-pass filter that separates the reproduction luminance signal during reproduction, even though the low-frequency conversion carrier color signal is not recorded.
Since the characteristics of the FM equalizer circuit were not set depending on whether or not it was a black and white signal, the band of the low-frequency conversion carrier color signal could not be effectively used, and a black and white signal with high resolution and inversion margin could not be reproduced. There was a problem such as.

Therefore, an object of the present invention is to provide a magnetic recording / reproducing method and a magnetic recording / reproducing apparatus in view of the above-mentioned conventional technique.

(Means for Solving Problems) The present invention provides the following configurations in order to achieve the above object.

A first invention is obtained by frequency-modulating a luminance signal having a frequency component equal to or higher than a color subcarrier frequency, to which an input composite video signal and an input luminance signal and an input carrier chrominance signal having a comb-shaped frequency component are supplied. In a magnetic recording / reproducing method of frequency-division-multiplexing a frequency-modulated luminance signal and a low-frequency carrier color signal obtained by frequency-converting a carrier color signal to a magnetic recording medium and reproducing the same, At this time, the presence or absence of a color signal in the signal to be recorded is detected.
A signal to be recorded is the input composite video signal, or a pilot signal having a different phase depending on whether the input luminance signal and the input carrier color signal is added to the color signal and recorded,
On the other hand, when the color signal is not included, the pilot signal is not recorded, and at the time of reproduction, the presence or absence of the color signal in the reproduction frequency division multiplexed signal reproduced from the recording medium is detected. When the phase of the reproduced pilot signal indicates that the input composite video signal has been recorded, the cutoff frequency of the high-pass filter that separates the reproduction luminance signal is set to a higher one, and the reproduced pilot signal is reproduced. When the phase of indicates that the input luminance signal and the input carrier color signal have been recorded, the high-pass filter is set to a lower cutoff frequency, while if the color signal is not included, The magnetic recording / reproducing method is characterized in that the cutoff frequency of the high-pass filter is set to a lower one.

A second invention has a first terminal to which an input composite video signal is supplied, and a second terminal to which an input luminance signal and an input carrier color signal having a comb-shaped frequency component are supplied.
Frequency-division-multiplexing a frequency-modulated luminance signal obtained by frequency-modulating a luminance signal having a frequency component higher than the color subcarrier frequency and a low-frequency carrier color signal obtained by frequency-converting the carrier color signal to a low frequency band. In a magnetic recording / reproducing apparatus for recording on a magnetic recording medium and reproducing the same, at the time of recording, the signal to be recorded has a phase depending on whether the input composite video signal, the input luminance signal or the input carrier color signal. Pilot signal generating means for respectively generating different pilot signals, recording color signal detecting means for detecting the presence or absence of a color signal in the signal to be recorded, and in the color signal if the signal to be recorded includes a color signal A recording unit that additionally records the pilot signal and does not record the pilot signal when the color signal is not included, a high-pass filter that separates a reproduction luminance signal during reproduction, and the reproduction brightness. Frequency modulation equalizing means for varying the frequency characteristics of the signal according to the cutoff frequency of the high pass filter, phase detecting means for detecting the phase of the reproduced pilot signal, and reproduction frequency division reproduced from the recording medium. A reproduction color signal detecting means for detecting the presence or absence of a color signal in the multiplex signal, wherein the reproduction frequency division multiplex signal contains a color signal, and the phase of the reproduced pilot signal is the input composite video. When indicating that a signal has been recorded, the cutoff frequency of the high-pass filter is set to the higher side, and the phase of the reproduced pilot signal indicates that the input luminance signal and the input carrier color signal have been recorded. Sometimes, when the high-pass filter is set to a lower cutoff frequency, and when the reproduction frequency division multiplexed signal does not include a color signal, , There is provided a magnetic recording / reproducing apparatus being characterized in that so as to set the lower cutoff frequency of the high pass filter.

(Embodiment) FIG. 1 is a block system diagram showing a configuration of a recording system of an embodiment of the present invention device, and FIG. 2 is a block system diagram showing a configuration of a reproduction system of an embodiment of the present invention device. In FIGS. 1 and 2, the same components as those shown in FIGS. 6 and 7 are designated by the same reference numerals.

The recording system of FIG. 1 differs from that of FIG. 6 in that a color detection circuit 91 for detecting whether or not an input signal is a color signal is provided depending on the presence or absence of a color signal in the input signal, and a gate circuit 92 is provided. The output of the ACC circuit 42 is connected to the color detection circuit 91, the output of the color detection circuit 91 is connected to the killer circuit 44, and the output of the color detection circuit 91 is connected to one input terminal of the gate circuit 92. Further, the output of the system controller 51 is connected to the other input terminal of the gate circuit 92, and the output of the gate circuit 92 is connected to the on / off control terminal of the switch circuit 52.

With the above configuration, at the time of recording, the color detection circuit 91 detects whether the input signal is a color signal,
When it is detected that the input signal is not a color signal, that is, a black and white signal, even if the input signal is supplied from the input terminal 31 for inputting a composite video signal, or a separate and independent luminance signal and color signal are input. The color detection circuit 91 outputs the “H” signal and supplies it to one input terminal of the gate circuit 92 even when supplied from the input terminals 49 and 50.

This gate circuit 92 is composed of an AND circuit,
The "H" signal is output as an AND logic with the signal supplied to the other input terminal, which turns on / off the switch circuit 52.
It becomes an off control signal. And in this way the switch circuit
It is assumed that the switch circuit 52 is turned on when the signal supplied as the on / off control signal to the 52 is the "H" signal, and is turned off when the signal is the "L" signal.

In this case, that is, when the "H" signal is supplied to one input terminal of the gate circuit 92, whether the signal supplied to the other input terminal of the gate circuit 92 is "H" or "L" (that is, Even in the wideband mode in which the input signal has a luminance signal band above the color subcarrier frequency, and in the narrowband mode in which the input signal has a luminance signal band below the color subcarrier frequency), the gate circuit 92 outputs a signal of "L". Since it outputs, the switch circuit 52 is turned off at this time. Therefore, the pilot signal is not supplied to the mixing circuit 41, and the pilot signal is not added to the color signal, that is, the pilot signal is not recorded.

At the same time, when it is detected that the input signal is not a color signal, that is, a monochrome signal as described above, the color detection circuit 91 similarly outputs an “H” signal, which is used as an operation control signal by the killer. The color signal is supplied to the circuit 44, and the killer circuit 44 is operated so that the color signal is not output to the LPF 45. At this time, the color signal is not recorded.

Next, in the reproduction system of FIG. 2, the difference from FIG. 7 is that
At the same time as the recording system, a color detection circuit 93 for detecting whether or not the input signal is a color signal depending on the presence or absence of a color signal in the input signal, and an OR circuit 94 are provided, and the output of the frequency converter 70. Is connected to the color detection circuit 93, and the output of this color detection circuit 93 is connected to the killer circuit 77.
Connect to one input terminal of the OR circuit 94. Further, the output of the pilot signal discrimination circuit 82 is connected to the other input terminal of the OR circuit 94, and the output of this OR circuit 94 is connected to the switching control terminal of the switch circuit 59.

With the above configuration, at the time of reproduction, the color detection circuit 93 detects whether or not the input reproduction signal is the color signal, and when the input reproduction signal is not the color signal, that is, the black and white signal, the color is detected. Detection circuit 93 is "H"
Signal is supplied to one input terminal of the OR circuit 94.

The "H" signal supplied to one input terminal of the OR circuit 94 is output as an OR logic with the signal supplied to the other input terminal, and this becomes the switching control signal of the switch circuit 59. Then, when the signal supplied to the switch circuit 59 as the switching control signal is "H", the movable contact piece of the switch circuit 59 is switched to the terminal b side, and when it is "L", the switch circuit 59 is switched.
It is assumed that the movable contact piece 59 is switched to the terminal a side.

In this case, that is, when the "H" signal is supplied to one input terminal of the OR circuit 94, the OR circuit 94 is set to "H" regardless of the signal supplied to the other input terminal of the OR circuit 94. Since a signal is output, the movable contact piece of the switch circuit 59 is switched to the terminal b side at this time. Therefore, at this time, the signal through the HPF60 having a low cutoff frequency and the FM equalizer circuit 61 having the characteristic suitable for this HPF60 is supplied to the limiter 62, and after the subsequent signal processing, it is reproduced. It

Further, in the cases other than the above, the OR circuit 94 outputs the signal of "L", and at this time, the movable contact piece of the switch circuit 59 is switched to the terminal a side. Therefore, at this time, the signal through the HPF57 having a high cutoff frequency and the FM equalizer circuit 58 having the characteristics suitable for this HPF57 is limited by the limiter.
It is supplied to 62, and after being subjected to subsequent signal processing, reproduced.

At the same time, when it is detected that the input signal is not a color signal, that is, a monochrome signal as described above, the color detection circuit 93 similarly outputs a signal of "H", which is used as an operation control signal by the killer. The color signal is supplied to the circuit 77 and the killer circuit 77 is operated so that the color signal is not output to the mixing circuit 68, and at this time, the color signal is not reproduced.

As described above, when recording, the input signal is not a color signal,
That is, when it is detected that the signal is a monochrome signal, the pilot signal is not recorded, and at the same time, the killer circuit 44 is operated so that the color signal is not recorded. Also, during playback, if the input playback signal is not a color signal, that is, it is detected as a monochrome signal, the cutoff frequency is low.
The signal via the HPF60 and the FM equalizer circuit 61 having the characteristics suitable for the HPF60 is reproduced, and at the same time, the killer circuit 77 is operated so that the color signal is not reproduced.

(Effects of the Invention) As described above, according to the magnetic recording / reproducing method and the magnetic recording / reproducing apparatus of the present invention, the pilot signal is recorded especially when the signal to be recorded does not include a color signal. When the reproduction frequency division multiplex signal reproduced from the recording medium does not contain a color signal and the reproduction frequency division multiplex signal does not contain a color signal, the reproduction luminance signal is separated. Since the cutoff frequency of the high-pass filter is set to the lower one, it is possible to record without superimposing the pilot signal on the black and white signal, and to cut off the high-pass filter regardless of the phase detection of the pilot signal during playback. Since the frequency can be determined, there is an effect that a stable black-and-white signal can be reproduced without fluctuation of the cutoff frequency due to erroneous detection of the pilot signal.

Also, when the black and white signal is played back, the cutoff frequency of the high-pass filter that separates the playback luminance signal is set low, so that the black and white signal can be played back based on the broadband playback luminance signal, resulting in high resolution. There is an effect that a black-and-white signal having a reversal margin can be reproduced.

Further, according to the magnetic recording / reproducing apparatus of the present invention, in particular, since the magnetic recording / reproducing apparatus has the frequency modulation equalizing means for varying the frequency characteristic of the reproduction luminance signal according to the cutoff frequency of the high-pass filter, the reversal margin can be improved with high resolution. There is an effect that a certain black and white signal can be surely reproduced.

[Brief description of drawings]

FIG. 1 is a block system diagram showing a configuration of a recording system of an embodiment of the present invention device, FIG. 2 is a block system diagram showing a configuration of a reproduction system of an embodiment of the present invention device, and FIG. 3 (a). (E) is a diagram showing a high-frequency luminance signal component to be recorded and a frequency band of a carrier color signal, and FIGS. 4 (a) and 4 (b) are structures of a recording system and a reproducing system of a conventional magnetic recording / reproducing apparatus. Block diagram, fifth
FIGS. 6A to 6D are views for explaining problems in recording a high band luminance signal having a wide band vertical correlation, and FIG. 6 is an apparatus proposed by the present applicant. FIG. 7 is a block system diagram showing the configuration of the recording system, FIG. 7 is a block system diagram showing the configuration of the reproducing system, FIG. 8 is a diagram showing the characteristics of the HPF which also constitutes the reproducing system, and FIG. It is a figure which shows a phase. 31,49,50 ...... Input terminal, 32,67,75 ...... comb filter, 33,39,52,59 ...... Switch circuit, 34,45,64,69,79 ...... Low range Pass filter (LPF), 35 …… Pre-emphasis circuit, 36 …… FM modulator, 37,41,68 …… Mixing circuit, 40,74 …… Band pass filter (BPF), 42 …… ACC circuit, 43 , 70 …… Frequency converter, 44,77 …… Killer circuit, 46 …… Recording amplifier, 47 …… Magnetic head, 48 …… Magnetic tape, 51 …… System controller, 53,80 …… Synchronous separation circuit, 54 ...... Pilot signal generation circuit, 56 …… Preamplifier, 57,60 …… High-pass filter (HPF), 58,61 …… Frequency modulation and equalization circuit (FM equalizer circuit), 62 …… Limiter, 63 …… FM Demodulator, 65 …… De-emphasis circuit, 66 …… Video equalizer circuit, 71 …… Phase comparator, 72 …… Variable voltage controlled oscillator (VCO), 73 …… Crystal oscillator (VXO) 76 ...... pilot signal cancellation circuit, 78 ...... output terminal, 81 ...... monostable multivibrator, 82 ...... pilot signal discrimination circuit, 91 and 93 ...... color detection circuit, 92 ...... gate circuit, 94 ...... AND circuit, S ₁ , S ₂ …… Switch.

Claims (2)

[Claims] 1. An input composite video signal and an input luminance signal and an input carrier chrominance signal having a comb-shaped frequency component are supplied, and a luminance signal having a frequency component equal to or higher than a color subcarrier frequency is frequency-modulated. A magnetic recording / reproducing method of frequency-division-multiplexing a frequency-modulated luminance signal and a low-frequency carrier color signal obtained by frequency-converting a carrier color signal into a magnetic recording medium, and recording and reproducing the same. At this time, the presence or absence of a color signal in the signal to be recorded is detected, and if the signal to be recorded includes a color signal, the signal to be recorded is the input composite video signal, the input luminance signal and the input carrier signal. When a pilot signal having a different phase depending on whether it is a color signal is added to each color signal and recorded, on the other hand, when the color signal is not included in the signals to be recorded,
When not reproducing the pilot signal, detecting the presence or absence of a color signal in the reproduction frequency division multiplex signal reproduced from the recording medium at the time of reproduction, in the case where the reproduction frequency division multiplex signal contains a color signal,
When the phase of the reproduced pilot signal indicates that the input composite video signal has been recorded, the cutoff frequency of the high-pass filter that separates the reproduction luminance signal is set to a higher one, and the reproduced pilot signal When the phase indicates that the input luminance signal and the input carrier color signal have been recorded, the high pass filter is set to the lower cutoff frequency, while the color signal in the reproduction frequency division multiplex signal is set. When not including, the magnetic recording / reproducing method is characterized in that the cutoff frequency of the high-pass filter is set to a lower one. 2. A color subcarrier having a first terminal supplied with an input composite video signal and a second terminal supplied with an input luminance signal and an input carrier color signal having a comb-shaped frequency component. Magnetic recording medium by frequency division multiplexing a frequency-modulated luminance signal obtained by frequency-modulating a luminance signal having a frequency component equal to or higher than a frequency and a low-frequency carrier color signal obtained by frequency-converting a carrier color signal into a low frequency band. Magnetic recording / recording and reproducing
In the reproducing device, at the time of recording, the signal to be recorded is the input composite video signal,
Pilot signal generating means for respectively generating pilot signals having different phases according to the input luminance signal and the input carrier color signal; recording color signal detecting means for detecting the presence or absence of a color signal in the signal to be recorded; When the signal to be included includes a color signal, the pilot signal is added to the color signal to record the pilot signal, and when the signal does not include the color signal, a recording unit that does not record the pilot signal; and a reproduction luminance signal during reproduction. A high-pass filter that separates the frequency component, frequency-modulation equivalent means that varies the frequency characteristic of the reproduction luminance signal according to the cutoff frequency of the high-pass filter, and phase detection that detects the phase of the reproduced pilot signal. And a reproduction color signal detecting means for detecting the presence or absence of a color signal in the reproduction frequency division multiplexed signal reproduced from the recording medium. When a color signal is included in the multiplex signal and the phase of the reproduced pilot signal indicates that the input composite video signal has been recorded, the cutoff frequency of the high pass filter is set to a higher one. When the phase of the reproduced pilot signal indicates that the input luminance signal and the input carrier color signal have been recorded,
The cutoff frequency of the high pass filter is set to the lower one, while the cutoff frequency of the high pass filter is set to the lower one when a color signal is not included in the reproduction frequency division multiplexed signal. A magnetic recording / reproducing apparatus characterized in that