JP3324689B2 - Magnetic recording / reproducing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the use of a standard format signal format in spite of using a magnetic tape (hereinafter referred to as "standard tape") for recording or reproducing a video signal in a standard format signal format. The present invention relates to a magnetic recording / reproducing apparatus capable of recording / reproducing a wideband video signal as compared with a video signal based on the above.

[0002]

2. Description of the Related Art Conventionally, a video tape recorder (hereinafter, referred to as a video tape recorder)
In the field of magnetic recording / reproducing devices such as “VTR”, a high-quality format in which the bandwidth of a video signal is expanded compared to a standard format has been proposed in order to improve the quality of recorded or reproduced video, and has been put to practical use. Have been. This is, for example, an S-VHS format (high-quality format) for the VHS format (standard format). A VTR corresponding to a high-quality format such as the S-VHS format has finer video or video compared to a VTR corresponding to the standard format. It has excellent reproducibility of image information and can maintain a reproduced image of sufficient image quality even when used by being connected to a television receiver having a large display screen, thereby satisfying the demands of consumers.

[0003] A V compatible with a high quality format
For the TR, a dedicated magnetic tape (hereinafter, referred to as “high-quality tape”) is used so that a video signal in a signal format of a high-quality format can be optimally recorded or reproduced. For example, a magnetic tape defined in the well-known IEC 744-3,
A so-called S-VHS tape is also one of the high quality tapes. Compared to standard tapes, high-quality tapes have improved magnetic energy characteristics, increased filling ratios, smoothed the surface of the magnetic tape, etc. It can record a signal of a wavelength.

As shown in FIG. 11A, a standard tape (V
When recording an NTSC signal in a standard format (VHS format) using an HS tape, the frequency shift of the luminance signal is set as low as 3.4 to 4.4 MHz, and the chrominance signal is subjected to low-frequency conversion. I have. On the other hand, as shown in FIG. 11B, when recording is performed in a high-quality format (S-VHS format) using a high-quality tape (S-VHS tape), the frequency shift of the luminance signal is 5.4 to less. 7.0M
Hz and a low frequency conversion of the color signal to realize higher resolution and higher S / N than at the time of recording in the standard format.

As described above, in the field of VTR, there are two formats, a standard format (VHS format) and a high quality format (S-VHS format). Here, considering the format of a video signal recordable and reproducible in a VTR corresponding to each format and a usable magnetic tape, first, in a VTR corresponding to a standard format, a standard tape is used by using a standard tape. In general, a video signal is recorded and reproduced in the signal format described above, but it is also possible to record and reproduce a video signal in a standard format signal format using a high-quality tape.

On the other hand, a VT compatible with a high image quality format
In R, it is common to record and reproduce video signals in a high-quality format signal format using a high-quality tape, but in order to achieve upward compatibility with a VTR compatible with a standard format, It is designed so that a video signal can be recorded and reproduced in a standard format signal form using a standard tape, and a video signal can be recorded and reproduced in a standard format signal form using the high-quality tape.

[0007] The housing of the high-quality tape has a tape type so that it can be determined whether the magnetic tape is a standard tape or a high-quality tape when used in a VTR compatible with the high-quality format. An identification hole is provided.

Recently, a VTR having a function of examining the characteristics of a magnetic tape so that an optimum signal can be recorded for each magnetic tape to be used and changing a characteristic or a recording level of a recording signal to record a signal has been developed. It has been commercialized. This function records and reproduces a test signal for examining tape characteristics before starting recording, and changes the recording signal characteristic or recording level during recording based on the characteristics of the reproduced test signal. The purpose is to maximize the performance of the tape and record video signals.

[0009]

However, even if the above-described functions are mounted on a VTR compatible with the high-quality format, the characteristics or recording level of the video signal is changed so that optimum signal recording is performed. If the magnetic tape to be used is a standard tape, the signal to be recorded is a video signal in a signal format of a standard format.

[0010] In recent years, standard tapes having performance comparable to high-quality tapes have been put on the market. However, even when such high-quality standard tapes are used, a video signal to be recorded is in a standard format. In this case, the video quality cannot be obtained beyond the standard format, and the video signal cannot be recorded by maximizing the performance of the magnetic tape.

On the other hand, the performance of a high-quality tape is improved as described above with the widening of the video signal, so that a sufficient video quality is obtained particularly when used in a VTR compatible with a high-quality format. On the other hand, there is a problem that the manufacturing cost is high. In such a situation,
Despite using standard tapes with low manufacturing costs,
Record wideband video signal for standard format,
A VTR capable of recording or reproducing a high-quality video signal has been desired.

[0012]

In order to solve the above problems, a magnetic recording / reproducing apparatus according to the present invention uses a standard tape for recording / reproducing a video signal in a standard format signal form. Record and play back a video signal in a high quality compatible format that has the characteristics of a video signal in a high quality format signal format in which the video signal band is expanded compared to a video signal in a standard format signal format.
It is characterized by having a high image quality mode . Further, the magnetic recording / reproducing apparatus according to the present invention includes a standard mode for recording / reproducing a video signal in a standard format signal format using a standard tape for recording / reproducing a video signal in a standard format signal format. A high-quality mode for recording and reproducing a video signal in a signal format of a high-quality format using a high-quality tape for recording and reproducing a video signal in a signal format of an image quality format; A high image quality compatible mode for recording and reproducing a high image quality compatible format video signal which is close to the characteristics of the video signal according to the signal format of the image quality format. Further, the magnetic recording / reproducing apparatus according to the present invention, when reproducing a video signal recorded on the standard tape, a format detecting means for detecting whether or not the reproduced video signal is a video signal of the format corresponding to the high image quality. Wherein the format detecting means detects the presence or absence of a tape type identification hole provided in a housing portion of the standard tape, and detects the frequency band of a reproduced video signal of the standard tape, thereby detecting the high image quality. It is characterized by detecting that it is a compatible format,
When the format detection means detects that the video signal recorded on the standard tape is a video signal of the high-quality compatible format, a part or all of a reproduction FM equalizer, a de-emphasis circuit, and a noise canceller are provided. Is changed as compared with the case of reproducing the video signal of the standard format or the high quality format. Change
In addition, the magnetic recording and reproducing apparatus according to the present invention
A filter that has the characteristic of amplifying the high-frequency component of the contained luminance signal
The re-emphasis circuit and the pre-emphasis circuit
A predetermined carrier is FM-converted by the luminance signal obtained by amplifying the band component.
FM modulation circuit to be tuned, and FM obtained by the FM modulation circuit
A modulated luminance signal and a color signal included in the input video signal.
An adder for frequency multiplexing, and a recording signal output from the adder.
A recording unit for recording a signal on a tape-shaped recording medium, and the tape
A reproducing unit for reproducing a recording signal recorded on the recording medium;
FM modulation luminance included in a reproduction signal reproduced by the reproduction unit
An FM demodulating circuit for demodulating the signal at the FM demodulation circuit
Compensate for high-frequency component amplification during recording of demodulated luminance signal
And a de-emphasis circuit having that characteristic, the high
When recording the input video signal in the image quality mode,
The characteristics of the pre-emphasis circuit in the standard mode and
At least 1 MHz or more compared to the high quality mode
While setting so that the amplification amount of the frequency component of
Set to increase as the attenuation increases,
Further, the FM modulation luminance signal output from the FM modulation circuit is output.
The frequency deviation of the signal is larger than in the standard mode, and
It is noted that the settings are the same as in the high image quality mode.
The input video signal in the high image quality mode.
Is recorded before being output from the FM modulation circuit.
The frequency shift of the FM modulated luminance signal is from 5.4 MHz.
The FM modulation circuit is controlled to be 7.0 MHz.
The pre-emphasis
White clip of luminance signal with high frequency component amplified by circuit
After adjusting the level, after adjusting the white clip level
A white signal for supplying the luminance signal of
A high-quality mode corresponding to the input signal.
When recording a video signal, the white clip circuit
Clip level at 190% ± 10%
Characterized in that the set, also the high image quality corresponding mode
When recording the input video signal at
Ratio of the FM modulated luminance signal and the chrominance signal
The cross-modulation distortion caused by the recording of each signal is high.
Set to fall within the range specified by the image quality format
It is characterized by doing so.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION In a magnetic recording / reproducing apparatus according to an embodiment of the present invention, when the type of a magnetic tape used for recording is a standard tape, whether the characteristics of the magnetic tape are higher than a predetermined reference characteristic or not. Discriminates whether or not it is higher than the reference characteristic, and performs predetermined processing on the recorded video signal so that a high-quality video signal beyond the frame of the conventional standard format is recorded, and records the signal. It has a corresponding recording mode. Further, the magnetic recording and reproducing apparatus according to the embodiment of the present invention determines whether the video signal recorded on the magnetic tape used at the time of reproduction is recorded in the high-quality corresponding recording mode, If it is determined that the magnetic tape is recorded in the high-quality recording mode, a predetermined process is performed on the reproduced video signal so that a high-quality video signal exceeding the frame of the conventional standard format is reproduced. It is characterized by having a reproduction mode corresponding to high image quality for signal reproduction.

Here, the processing of the signal recording system of the magnetic recording and reproducing apparatus will be described first. FIG. 1 is a block diagram of a video signal recording system of a magnetic recording / reproducing apparatus according to the present invention. Here, the standard format is VH for convenience.
The S format and the high quality image format will be described as an S-VHS format, and the standard tape and the high quality image tape will be described as a VHS tape and an S-VHS tape corresponding to the respective formats.

As shown in FIG. 1, the signal flow in the video signal recording system of the magnetic recording / reproducing apparatus according to the present invention includes the input luminance signal and chrominance signal, the luminance signal is a luminance signal recording system, and the chrominance signal is Processing is performed by a color signal recording system, and a recording signal obtained by frequency-multiplexing the FM modulated luminance signal output from the luminance signal recording system and the low-frequency conversion color signal output from the color signal recording system is recorded. The data is recorded on a magnetic tape via an amplifier and a magnetic head.

In the luminance signal recording system, reference numeral 10 denotes a low-pass filter for removing high-frequency components of the input luminance signal;
Reference numeral 11 denotes a detail enhancer for compensating for a signal removed by a noise canceller during reproduction, and reference numeral 12 denotes a pre-emphasis circuit including a non-linear emphasis 12a and a linear emphasis 12b. The non-linear emphasis 12a and the linear emphasis 12b enhance the high-frequency component of the luminance signal that is input together to improve the S / N ratio. In contrast to the emphasis irrelevant, the nonlinear emphasis 12a is different in that the higher the high frequency component of the luminance signal is, the lower the level is, and the higher the level, the less the emphasis is.

Reference numeral 13 denotes the pre-emphasis circuit 1
A white / dark clipping circuit for removing sharp spike signals at the rising and falling portions of the luminance signal emphasized in step 2 and suppressing the occurrence of inversion phenomena, and 14 for FM-modulating the luminance signal from which the spike signals have been removed This is an FM modulation circuit.

Here, the detail enhancer 11,
The characteristics of the pre-emphasis circuit 12 and the white / dark clip circuit 13 are respectively determined by control signals from the microcomputer 33 as described later. And
The FM modulation circuit 14 includes a microcomputer 33 as described later.
, The frequency shift of the luminance signal is set to a frequency band corresponding to the VHS format or the S-VHS format.

Further, a test signal having a predetermined frequency for detecting the characteristics of the magnetic tape when the magnetic tape used in the identification hole detecting section 35 described later is determined to be a VHS tape is sent to the FM modulation circuit 14. An oscillator is provided inside so as to be able to output. The luminance signal input to the luminance signal recording system in the above flow is output to the adder 30 as an FM modulated luminance signal.

On the other hand, in the color signal recording system, reference numeral 20 denotes a low-frequency conversion circuit for low-frequency conversion of an input color signal, and the input color signal is output to the adder 30 as a low-frequency conversion color signal. . In the color signal recording system, signal processing other than the low-frequency conversion of the color signal by the low-frequency conversion circuit 20 is also performed, but detailed description is omitted.

Numeral 30 denotes an adder for adding the input FM-modulated luminance signal and the low-frequency conversion color signal by frequency multiplexing. The recording signal output from the adder 30 is supplied by a recording current equalizer 31 through a video head system. Is compensated for by the recording amplifier 32 to a signal level suitable for recording on a magnetic tape, and is recorded on a magnetic tape housed in a tape cassette K via a rotary transformer and a rotary magnetic head (not shown). You.

Here, the FM in the adder 30
The mix ratio between the modulated luminance signal and the low-frequency conversion color signal, the frequency characteristic of the recording current equalizer 31, and the amplification amount of the recording amplifier 32 are determined by control signals from the microcomputer 33 as described later.

The luminance signal and the chrominance signal input as described above are processed by a luminance signal recording system and a chrominance signal recording system, respectively, added by an adder 30, and then amplified by a recording amplifier 32. It is recorded on a magnetic tape via a rotary transformer and a rotary magnetic head (not shown).

Next, the main part of the recording system of the magnetic recording / reproducing apparatus according to the embodiment of the present invention will be described. Here, K is a tape cassette loaded in the magnetic recording / reproducing apparatus, and contains the magnetic tape therein.

Numeral 34 designates a tape characteristic detecting section for detecting the tape characteristic of the magnetic tape in the tape cassette K loaded in the magnetic recording / reproducing apparatus. Numeral 35 designates a tape type identification hole provided in the housing of the tape cassette K. An identification hole detection unit 33 that determines whether the loaded tape is a VHS tape or an S-VHS tape depending on the presence or absence is a detection signal from the tape characteristic detection unit 34 and the identification hole detection unit 35. The recording mode for recording a video signal on a magnetic tape is determined based on the above, and the detail enhancer 11, the pre-emphasis circuit 12, the white / dark clip circuit 13, the FM modulation circuit 14, The respective characteristics of the adder 30, the recording current equalizer 31, and the recording amplifier 32 are changed. It is an icon.

Next, the recording operation of the magnetic recording / reproducing apparatus according to the embodiment of the present invention will be described. First, when the user loads the tape cassette K into the magnetic recording / reproducing apparatus, the identification hole detection unit 35 sets the tape based on the presence or absence of a tape type identification hole provided in the housing of the loaded tape cassette K. It detects whether the magnetic tape stored in the cassette K is a VHS tape or an S-VHS tape, and sends a detection signal to the microcomputer 33.

In this state, if it is detected that the magnetic tape accommodated in the tape cassette K is a VHS tape, the user can perform a predetermined recording operation in which the loaded magnetic tape can perform recording in the high image quality recording mode. It will be checked whether or not the magnetic tape has a standard characteristic or higher.

FIG. 2 shows a microcomputer 3 according to the detection signals of the identification hole detection unit 35 and the tape characteristic detection unit 34 of the cassette K.
FIG. 6 is an explanatory diagram showing a result of discrimination of a recording mode according to No. 3 and a control situation of each circuit at that time.

First, a test signal of a predetermined frequency is recorded on a magnetic tape at a predetermined recording level. At this time, a test signal from an oscillator (not shown) inside the FM modulation circuit 14 is amplified to a predetermined recording level by a recording amplifier 32 via an adder 30 and a recording current equalizer 31 based on a control signal from a microcomputer 33, and a magnetic signal (not shown) It is recorded on a magnetic tape through a head. Thereafter, the test signal is reproduced from the magnetic tape, and the tape characteristic detecting section 34 determines which output level of the reproduced signal corresponds to, for example, which one of the levels 1 to 3, for example, the lowest output level. If it is determined to be 1, the recording mode is V
If the recording mode is the HS recording mode and the level is determined to be level 2 or level 3, the recording mode is set to the high image quality recording mode. On the other hand, if it is determined that the magnetic tape stored in the tape cassette K is an S-VHS tape, the recording mode is set to the regular S-VHS recording mode.

Here, the high image quality recording mode is defined as S-
This mode records video signals in the same frequency band as the VHS format, but in order to record video signals in the same frequency band as the S-VHS format on a VHS tape, the detail enhancer 11, the pre-emphasis circuit 12, The white / dark clip circuit 13
And the characteristics of the recording current equalizer 31 are S-VHS
It is necessary to change it in comparison with the recording mode, and further to change the mix ratio of the adder 30 according to the signal recording level of the recording amplifier 32.

That is, in the high-quality recording mode in which a high-quality signal is recorded on a VHS tape, the S-VHS tape is
The characteristics of each circuit are changed so that a signal close to the signal recorded in the -VHS recording mode is recorded.

A VHS tape on which a video signal is recorded in the recording mode corresponding to the high image quality can be reproduced without any trouble in the S-VHS reproduction mode by the VTR corresponding to the S-VHS format. By playing back, it is possible to obtain a still higher quality playback video.

In the VHS recording mode or the S-VHS recording mode, the microcomputer 33 controls the detail enhancer 11, the pre-emphasis circuit 12, the white
Each of the dark clip circuit 13, the FM modulation circuit 14, the adder 30, the recording current equalizer 31, and the recording amplifier 32 is controlled in accordance with the VHS format or the S-VHS format. Control is performed as follows according to the reproduction signal output level of the tape characteristic detection unit 34 or the signal recording level of the recording amplifier 32.

First, both the detail enhancer 11 and the pre-emphasis circuit 12 have a characteristic of mainly amplifying the high frequency component of the input luminance signal. Is suppressed. FIG. 3 is a diagram showing an example of the characteristics of the linear emphasis 12b in the VHS recording mode, the high image quality recording mode, and the S-VHS recording mode, respectively.

Next, in the white / dark clip circuit 13, the level of the white clip is 210% ± 10% in the S-VHS recording mode, while it is, for example, 190% ± 10% in the high image quality recording mode. Can be suppressed. This is because, as shown in FIGS. 4A and 4B, the VHS tape has a larger attenuation of the reproduction level in the high frequency range than the S-VHS tape, and the shortest recording is achieved by lowering the white clip. The wavelength is suppressed to suppress the inversion phenomenon.

In the high image quality recording mode, FM
In the modulation circuit 14, the luminance signal is FM-modulated with the same frequency signal of 5.4 MHz to 7.0 MHz as in the S-VHS format. Therefore, the recording signal frequency allocation when the video signal is recorded in the recording mode corresponding to the high image quality is the same as the recording signal frequency allocation of the S-VHS format shown in FIG.

The adder 30 changes the mix ratio between the FM modulation luminance signal and the low-frequency conversion color signal according to the output level (level 2 or level 3) of the tape characteristic detecting section 34. At this time, the mix ratio between the FM-modulated luminance signal and the low-frequency conversion chrominance signal is such that the intermodulation distortion generated when each signal is recorded on a magnetic tape falls within the range specified in the S-VHS format. Is set.

Further, in the recording current equalizer 31, as shown in FIGS. 4A and 4B, in order to compensate for the difference in the electromagnetic conversion frequency characteristics between the S-VHS tape and the VHS tape to be used, a high image quality is obtained. In the corresponding recording mode, S-VH
The characteristic is changed to a characteristic in which a low-frequency component is particularly suppressed as compared with the characteristic defined in the S format.

FIG. 5 shows an example of the characteristics of the recording current equalizer 31 at this time.
Compared with the HS tape, the decrease in the maximum reproduction output level obtained when the signal is recorded at the optimum recording level is larger at the high frequency band, so that this is compensated.

Finally, in the recording amplifier 32, based on the control signal from the microcomputer 33, the output signal of the recording current equalizer 31 is amplified so as to have the same signal recording level as when the test signal was recorded, The signal is recorded on the

Here, the characteristics of the detail enhancer 11, the pre-emphasis circuit 12, the white / dark clip circuit 13, and the recording current equalizer 31 in the aforementioned luminance signal recording system can be changed by a control signal from the microcomputer 33. When the output level of the tape characteristic detecting section 34 is level 2, for example,
All the recording characteristics 1 to 13 and 31 are changed in accordance with the recording mode corresponding to the high image quality.
Instead of changing all the recording characteristics of the above-mentioned 13 to 31 and 31, the specific circuits of the above-mentioned 11 to 13 and 31 are selectively changed in accordance with the high image quality recording mode.

By the above-described signal processing, 5.4 MHz to 7.0 M which can be reproduced on the magnetic tape in the tape cassette K by a VTR compatible with the S-VHS format.
A video signal having a frequency band of Hz can be recorded.

Next, the processing of the signal reproducing system of the magnetic recording / reproducing apparatus will be described. FIG. 6 is a block diagram showing a video signal reproducing system of the magnetic recording / reproducing apparatus according to the present invention.

The signal flow in the video signal reproducing system of the magnetic recording and reproducing apparatus according to the present invention is such that a signal recorded on a magnetic tape stored in the tape cassette K is reproduced through a magnetic head and a reproducing amplifier (not shown). The luminance signal is processed by a luminance signal reproduction system, the color signal is processed by a color signal system, and a reproduction luminance signal output from the luminance signal reproduction system and a reproduction color signal output from the color signal reproduction system are required. In addition, a reproduced video signal is obtained.

First, in the reproduction amplifier 36, a reproduction signal amplified to a predetermined level is processed in a luminance signal reproduction system and a chrominance signal reproduction system. In the luminance signal reproduction system, reference numeral 40 denotes a high-pass filter that removes a low-frequency component of an input reproduction signal and extracts a luminance signal component. Reference numeral 41 denotes a reproduction F that compensates for frequency characteristics and group delay characteristics of a tape head system.
M equalizer, 42 is a double limiter that separates an input signal into a high-frequency signal and a low-frequency signal and applies a limiter to suppress the occurrence of an inversion phenomenon; 43 is an FM demodulation circuit that demodulates the reproduced signal to which the limiter has been applied; Is a de-emphasis circuit composed of a linear de-emphasis 44a and a non-linear de-emphasis 44b.

The linear de-emphasis 44a and the non-linear de-emphasis 44b are S / N by returning the high-frequency component emphasized by the luminance signal recording system at the time of recording.
As in the case of recording, the linear de-emphasis 44a returns the high-frequency component to the original signal level without depending on the input signal level, and the non-linear de-emphasis changes the high-frequency component depending on the input signal level. Returns the component to the original signal level. Reference numeral 45 denotes a low-pass filter for removing a carrier wave included in the luminance signal, and reference numeral 46 denotes a noise canceller for removing a noise component distributed in a high frequency band.

Here, the characteristics 41 to 46 in the luminance signal reproduction system are determined by control signals from the microcomputer 33 as described later. The reproduction luminance signal is output from the luminance signal reproduction system in the above flow.

On the other hand, in the color signal reproduction system, reference numeral 50 denotes a low-pass filter for extracting only a color signal component from the reproduction signal, and reference numeral 51 denotes a high-pass filter for returning a color signal subjected to low-frequency conversion by a low-frequency conversion circuit to an original signal during recording. This is a conversion circuit, and a reproduction signal from the reproduction amplifier 36 is output as a reproduction color signal. In the color signal reproduction system, signal processing other than the signal processing in the low-pass filter 50 and the high-frequency conversion circuit 51 is also performed, but detailed description is omitted.

Next, the main part of the reproducing system of the magnetic recording / reproducing apparatus according to the embodiment of the present invention will be described. Here, K is a tape cassette loaded in the magnetic recording / reproducing apparatus, and contains the magnetic tape therein. Reference numeral 35 denotes an identification hole detection unit that determines whether the loaded tape is a VHS tape or an S-VHS tape by using a tape type identification hole provided in the housing of the tape cassette K. Reproduction FM in luminance signal reproduction system
2. Based on the signal output from the equalizer 41, the frequency shift of the reproduced signal is specified in the VHS format.
A frequency shift detector for detecting whether the frequency is 4 to 4.4 MHz or 5.4 to 7.0 MHz specified in the S-VHS format;
And a microcomputer which determines a reproduction mode at the time of video signal reproduction based on a detection signal from the frequency shift detection unit 37 and changes each of the characteristics 41 to 46 in the luminance signal reproduction system according to the reproduction mode. .

Next, the operation of the magnetic recording / reproducing apparatus according to the embodiment of the present invention during reproduction will be described. First, when the user loads the tape cassette K into the magnetic recording / reproducing apparatus, the identification hole detection unit 35 sets the tape based on the presence or absence of a tape type identification hole provided in the housing of the loaded tape cassette K. It detects whether the magnetic tape stored in the cassette K is a VHS tape or an S-VHS tape, and sends a detection signal to the microcomputer 33.

When the user gives an instruction to start the reproducing operation to the magnetic recording / reproducing apparatus, the reproduced signal is input to the frequency shift detecting unit 37 via the high-pass filter 40 and the reproduced FM equalizer 41 in the luminance signal reproducing system. The frequency shift detecting unit 37 determines that the signal recorded on the magnetic tape is 3.4 to 4.0 according to the VHS format.
With a frequency shift of 4 MHz or S-VHS
It detects whether it has a frequency shift of 5.4 to 7.0 MHz specified in the format, and sends a detection signal to the microcomputer 33.

Then, the microcomputer 33 determines the reproduction mode as shown in FIG. 7 based on the detection signals from the identification hole detection section 35 and the frequency shift detection section 37, and determines the reproduction modes 41 to 46 in the luminance signal reproduction system. Are controlled in accordance with each reproduction mode. The reproduction mode includes a VHS reproduction mode for reproducing a video signal in a VHS format signal form, an S-VHS reproduction mode for reproducing a video signal in a S-VHS format signal form,
There is a reproduction mode corresponding to high image quality for reproducing a video signal recorded in the recording mode corresponding to high image quality with high image quality.

In the reproduction mode corresponding to the high image quality, the SV recorded on the VHS tape in the recording mode corresponding to the high image quality is used.
In order to reproduce a video signal having the same frequency band as the HS format, the reproduction FM in the luminance signal reproduction system is used.
The respective characteristics of the equalizer 41, the de-emphasis circuit 44 and the noise canceller 46 are changed in comparison with the S-VHS reproduction mode.
It is necessary to control each of the double limiter 42, the FM demodulation circuit 43, and the low-pass filter 45 with reproduction characteristics specified in the S-VHS format.

In the VHS reproduction mode or the S-VHS reproduction mode, the microcomputer 33 converts the luminance signal reproduction system 41 to 46 into the VHS format or the S-VHS
Control is performed in accordance with the definition of the format. In the reproduction mode corresponding to high image quality, the characteristics of the reproduction FM equalizer 41, the de-emphasis circuit 44, and the noise canceller 46 in the luminance signal reproduction system are controlled as follows.

First, the reproduction FM equalizer 41 compensates for changes in the frequency characteristic and the group delay characteristic of the tape head system which occur during the recording / reproduction process.
As shown in (a), the characteristics are changed so as to suppress the emphasis of the low band side band as compared with the S-VHS reproduction mode. Here, as shown in FIG. 8B, the same effect is obtained by changing the characteristic so as to increase the Q of the peaking characteristic and changing the characteristic so as to relatively suppress the emphasis of the low-frequency side band. By changing the characteristics in this way,
A margin for the occurrence of the reversal phenomenon in the reproduction mode corresponding to the high image quality can be secured to the same degree as in the S-VHS reproduction mode.

Next, the de-emphasis circuit 44 restores the high-frequency component emphasized by the pre-emphasis circuit 12 of the luminance signal recording system at the time of recording. Here, the total frequency characteristic and pulse at the time of reproduction are used. The characteristics are also corrected. S-VHS in high quality playback mode
As compared with the reproduction mode, the suppression of the white clip level at the time of recording causes dullness in the rising portion of the waveform of the luminance signal demodulated by the FM demodulation circuit 43 as shown in FIG. In addition, since the VHS tape is used in the reproduction mode corresponding to high image quality, the frequency characteristic of the luminance signal after demodulation also changes as compared with the case where the S-VHS tape is used.

Therefore, the de-emphasis circuit 44 corrects the bluntness of the rising portion of the waveform of the luminance signal caused by the suppression of the white clip level.
The frequency characteristic is made substantially flat as shown in FIG. 9 so as to correct the fluctuation of the frequency characteristic due to the use of the HS tape. Here, for the purpose of enhancing the outline of the reproduced image, the frequency characteristic may be changed so that the rising portion of the waveform of the luminance signal becomes sharp.

The noise canceller 46 removes noise components distributed in a high frequency range. In the high-quality playback mode, VHS tape is used.
Compared with the S-VHS playback mode using a VHS tape, the C / N of the signal obtained from the magnetic tape during playback is slightly inferior. As a result, the amount of noise components included in the reproduced signal also increases.

Therefore, as shown in FIG. 10, the characteristic is changed so as to enhance the effect of the noise canceller as compared with the S-VHS reproduction mode, and the S / V in the high image quality reproduction mode.
N is to be secured to the same extent as in the S-VHS playback mode.

By the above-described signal processing, a video signal having the same frequency band as the S-VHS format recorded on the VHS tape in the high image quality recording mode can be reproduced with high image quality.

In the magnetic recording / reproducing apparatus described above, an example is shown in which the characteristic of the noise canceller 46 in the luminance signal reproducing system at the time of reproduction is changed, but the YNR using the 1H delay line, the field memory, etc. 3D Y used
In the NR, similarly, the characteristics may be changed so as to enhance the effect of the noise canceller. Further, not only the luminance signal but also the color signal may be similarly changed in the CNR using a 1H delay line or the three-dimensional CNR using a field memory or the like so as to enhance the effect of the noise canceller.

Further, the magnetic recording and reproducing apparatus described above has both a video signal recording system and a video signal reproducing system. However, the present invention can be applied to a magnetic reproducing apparatus having no video signal recording system. Needless to say, the same technical idea as that of the video signal reproducing system can be applied.

[0063]

As described above, in the magnetic recording / reproducing apparatus according to the embodiment of the present invention, although the tape to be used is a standard tape, the characteristics and the signal of the recording signal are changed according to the characteristics of the standard tape to be used. By changing the recording level, it is possible to record a video signal having an image quality close to a high image quality format. Further, in the magnetic recording / reproducing apparatus according to the embodiment of the present invention, recording / reproducing was performed in the high-quality format by reproducing the standard tape on which the video signal was recorded in the high-quality corresponding recording mode in the high-quality corresponding reproducing mode. As compared with the case, it is possible to obtain a reproduced video of comparable image quality.

[Brief description of the drawings]

FIG. 1 is a block diagram of a video signal recording system of a magnetic recording and reproducing apparatus according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a control state of each circuit of a luminance signal recording system and a recording current equalizer 31.

FIG. 3 is a diagram illustrating an example of a change in characteristics in a VHS recording mode, a high image quality compatible recording mode, and an S-VHS recording mode in the linear emphasis 12b.

FIG. 4 is a diagram illustrating electromagnetic conversion frequency characteristics of a VHS tape and an S-VHS tape.

FIG. 5 is a diagram illustrating an example of a change in characteristics of a recording current equalizer 31 in a VHS recording mode, a high image quality recording mode, and an S-VHS recording mode.

FIG. 6 is a block diagram of a video signal reproducing system of the magnetic recording / reproducing apparatus according to the embodiment of the present invention.

FIG. 7 is an explanatory diagram showing a control state of each circuit of a luminance signal reproduction system.

FIG. 8 is a diagram illustrating an example of a change in characteristics of a reproduction FM equalizer 41.

FIG. 9 is a diagram illustrating correction of dullness at a rising portion of a waveform of a demodulated luminance signal.

FIG. 10 is a diagram illustrating an example of a change in characteristics in the noise canceller 46.

FIG. 11 is a diagram showing recording signal frequency allocation in VHS format and S-VHS format.

[Explanation of symbols]

 10, 45, 50 LPF 11 Detail enhancer 12a Nonlinear emphasis 12b Linear emphasis 13 White / dark clip circuit 14 FM modulation circuit 20 Low frequency conversion circuit 30 Adder 31 Recording current equalizer 32 Recording amplifier 33 ... Microcomputer 34 ... Tape characteristic detection unit 35 ... Identification hole detection unit 36 ... Reproduction amplifier 37 ... Frequency shift detection unit 40 ... HPF 41 ... Reproduction FM equalizer 42 ... Double limiter 43 ... FM demodulation circuit 44a ... Linear de-emphasis 44b ... Nonlinear de-emphasis 46 ... Noise canceller 51 ... High frequency conversion circuit K ... Tape cassette

Continued on the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) H04N 5/91-5/956 H04N 5/782-5/783 H04N 9/79-9/898

Claims (9)

(57) [Claims] 1. A high-quality format signal in which a video signal band is expanded by using a standard tape for recording and reproducing a video signal in a standard format signal format as compared with a video signal in the standard format signal format. There is a high-quality mode that records and reproduces video signals in a format that supports high image quality that approximates the characteristics of video signals depending on the mode.
A magnetic recording / reproducing apparatus. 2. A standard tape for recording and reproducing a video signal in a standard format signal format is used to record and reproduce a video signal in a standard format signal format.
A standard mode, and a high-quality mode for recording and reproducing a video signal in a high-quality format signal form using a high-quality tape for recording and reproducing a video signal in a high- quality format signal form; using standard tape, and having a high image quality corresponding mode <br/> de for recording and reproducing a video signal of high image quality corresponding format closer to the characteristics of the video signal by the signal form of the high-quality format Magnetic recording and reproducing device. 3. A format detecting means for detecting whether or not a reproduced video signal is a video signal of the format corresponding to the high image quality when reproducing a video signal recorded on the standard tape. Item 3. The magnetic recording / reproducing apparatus according to item 1 or 2. 4. A format corresponding to the high image quality by detecting presence / absence of a tape type identification hole provided in a housing portion of the standard tape and detecting a frequency band of a reproduced video signal of the standard tape. 4. The magnetic recording / reproducing apparatus according to claim 3, wherein the detection is performed. 5. When the format detection means detects that the video signal recorded on the standard tape is a video signal of the high quality compatible format, the reproduction FM
5. The method according to claim 4, wherein some or all of the characteristics of the equalizer, the de-emphasis circuit, and the noise canceller are changed as compared with the case of reproducing the video signal of the standard format or the high quality format. Magnetic recording and reproducing device. 6. A high-frequency component of a luminance signal included in an input video signal.
A pre-emphasis circuit having a characteristic of amplifying a component, and a luminance signal obtained by amplifying a high frequency component by the pre-emphasis circuit.
An FM modulation circuit for FM modulating a predetermined carrier with a signal, an FM modulation luminance signal obtained by the FM modulation circuit,
Adder that frequency-multiplexes the color signal contained in the video signal
And the recording signal output by the adder is recorded on a tape-shaped recording medium.
A recording unit for recording, and reproducing a recording signal recorded on the tape-shaped recording medium.
A reproducing unit, and an FM modulation luminance included in a reproduced signal reproduced by the reproducing unit.
An FM demodulation circuit for demodulating a signal; and a high-level signal for recording a luminance signal demodulated by the FM demodulation circuit.
De-emphasis with characteristics to compensate for the band component amplification
Circuit for recording the input video signal in the high image quality compatible mode.
, The characteristics of the pre-emphasis circuit and the standard mode and
At least 1 MHz or more compared to the high quality mode
While setting so that the amplification amount of the frequency component of
It is set so that the attenuation increases as the frequency increases, and further, the FM modulation luminance signal output from the FM modulation circuit is output.
The frequency deviation of the signal is larger than in the standard mode, and
It is noted that the settings are the same as in the high image quality mode.
The magnetic recording / reproducing apparatus according to claim 1 or 2, wherein: 7. The input video signal in the high image quality compatible mode.
Is recorded before being output from the FM modulation circuit.
The frequency shift of the FM modulated luminance signal is from 5.4 MHz.
The FM modulation circuit is controlled to be 7.0 MHz.
Magnetic recording reproducing 請 Motomeko 6, wherein a was Unishi
apparatus. 8. The high frequency component is increased by the pre-emphasis circuit.
After adjusting the white clip level of the broadened luminance signal
The luminance signal after the white clip level adjustment is
Equipped with a white clip circuit to supply to the M modulation circuit
And when recording the input video signal in the high image quality compatible mode.
Is the white clip in the white clip circuit.
The top level is set to 190% ± 10%
The magnetic recording / reproducing apparatus according to claim 7, wherein 9. The input video signal in the high image quality compatible mode
When recording the FM modulated brightness in the adder,
The addition ratio between the degree signal and the color signal is determined by recording each signal.
Intermodulation distortion caused by the
Is set to be within the specified range.
7. The magnetic recording / reproducing apparatus according to claim 6, wherein: