JPH11220757A - Video signal processing circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a video signal processing circuit that can be commonly used by VTRs of both formats, that is, a VTR corresponding to a VHS (standard) format and a VTR corresponding to an S-VH(high image quality) format. SOLUTION: An additional circuit 2 can be connected to a VHS signal processing circuit 1 for signal processing of a VHS format, in which the VHS signal processing circuit 1 itself can be used as a signal processing circuit of a VHS format corresponded VTR corresponding to the VHS format. When the additional circuit 2 is connected to the VHS signal processing circuit, it can be used as a signal processing circuit of an S-VHS format corresponded based VTR corresponding to an S-VHS format.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is mainly used in a magnetic recording / reproducing apparatus such as a video tape recorder, and can perform signal processing of a video signal in a standard format signal form. Is a video signal processing circuit that can also perform signal processing of a video signal in a signal format of a high image quality format.

[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] As described above, in the field of VTR, there are two formats, a standard format and a high quality format.
The S format and the high image quality format will be described as S-VHS formats.

First, a VT compatible with the VHS format
Considering the format of a video signal recorded and reproduced by a VTR compatible with the R and S-VHS formats,
In a VTR compatible with the S format, a video signal is recorded and reproduced in the VHS format. On the other hand, S-
In a VTR compatible with the VHS format, S-
Generally, video signals are recorded and reproduced in the VHS format.
In order to achieve upward compatibility with the VHS format, it is designed to record and reproduce video signals even in the VHS format.

That is, a VT compatible with the VHS format
In R, video signal processing is performed by providing a video signal processing circuit for VHS format in order to record and reproduce a video signal in a signal format of VHS format. However, in a VTR compatible with S-VHS format,
It is necessary to record and reproduce both video signals in the VHS format and the S-VHS format, and a video signal processing circuit for the S-VHS format is provided in addition to a video signal processing circuit for the VHS format.

[0006]

The video signal processing circuit described above uses a VTR compatible with the VHS format.
And a VTR compatible with S-VHS require separate video signal processing circuits, so that it is necessary to develop each video signal processing circuit separately, leading to an increase in man-hours in terms of design man-hours. In recent years, these video signal processing circuits are generally configured using integrated circuits. However, VTR and S-
A video signal processing circuit using an integrated circuit developed separately from a VTR compatible with the VHS format was mounted.

In such a situation, when used in a VTR compatible with the VHS format, it operates as a video signal processing circuit for processing a signal in the VHS format, and is used in a VTR compatible with the S-VHS format. In this case, VH is connected by using an additional circuit.
There has been a need for a video signal processing circuit that operates as a video signal processing circuit that can process both S-format signals and S-VHS format signals.

[0008]

In order to solve the above-mentioned problems, a video signal processing circuit according to the present invention provides a recording system for performing a signal processing of a recording system on a luminance signal included in an input composite signal. A video signal processing circuit including a luminance signal processing unit and a recording color signal processing unit that performs recording signal processing on a color signal included in the composite signal, and outputs a recording signal in a standard format signal form. The video signal processing circuit can be connected to a high-quality signal processing circuit for obtaining a recording signal in a high-quality format signal form in which a signal band is expanded as compared with the recording signal in the standard format signal form, The video signal processing circuit alone can output only the recording signal in the signal format of the standard format, and the high-quality signal processing circuit is used as the video signal processing circuit. In the case of continuing, by sharing the video signal processing circuit, it is possible to selectively output a recording signal in the signal format of the standard format and a recording signal in the signal format of the high-quality format, The video signal processing circuit alone can be used as a recording system video signal processing circuit of a magnetic recording device compatible with the standard format, and when the high image quality signal processing circuit is connected to the video signal processing circuit, the high image quality format It can be used as a video signal processing circuit of a recording system of a magnetic recording apparatus corresponding to.

Further, a video signal processing circuit according to the present invention is a reproduction system luminance signal processing section for performing a reproduction system signal process on a luminance signal included in a reproduction signal of a standard format reproduced from a magnetic tape. And a reproduction system color signal processing unit for performing reproduction system signal processing on a color signal included in the reproduction signal, a video signal processing circuit that outputs a reproduction composite signal, the video signal processing circuit, A high-quality signal processing circuit for reproducing a reproduction signal in a signal format of a high-quality format in which a signal band is expanded as compared with a reproduction signal in a signal format of a standard format can be connected. Only the reproduction signal in the format signal format can be reproduced, and when the high image quality signal processing circuit is connected to the video signal processing circuit, By sharing the video signal processing circuit, it is possible to selectively reproduce the reproduction signal in the signal format of the standard format and the reproduction signal in the signal format of the high-quality format, the video signal processing circuit alone When the high-quality signal processing circuit is connected to the video signal processing circuit, it can be used as a reproduction-system video signal processing circuit of a magnetic recording device compatible with the standard format. It is characterized in that it can be used as a reproduction system video signal processing circuit of the device.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a video signal processing circuit according to an embodiment of the present invention will be described with reference to the drawings. FIG.
FIG. 3 is a block diagram for explaining a recording system of the video signal processing circuit according to the embodiment of the present invention. As shown in FIG. 1, the recording system of the video signal processing circuit according to the embodiment of the present invention has VH
It comprises an S signal recording circuit 1 and an S-VHS signal recording circuit 2 connected to and used with the VHS signal recording circuit 1. When the VHS signal recording circuit 1 is used alone, a VHS format image is displayed. When the S-VHS signal recording circuit 2 is connected to the VHS signal recording circuit 1 and used, signal processing of the signal recording system can be performed.
It can perform signal processing of the recording system of the S-VHS format video signal in addition to the HS format video signal.

Here, the VHS signal recording circuit 1 will be described first. SW1 supplies a composite video signal input via an input terminal InV to a connection point A via an output terminal A when the composite video signal is connected to an S-VHS signal recording circuit 2 described later, or a VHS signal described later. This is a first switch that supplies the signal to the AGC circuit 10 of the recording circuit 1 via the output terminal B or selects and outputs one of the signals.

An automatic gain control circuit (AG) 10 automatically adjusts the signal level of the composite video signal input via the output terminal B of the first switch to an appropriate signal level.
C) and 11 are 3M because only the luminance signal is extracted from the composite video signal output from the automatic gain control circuit 10.
Low-pass filter (L
PF) and SW2 are S-VHS signal recording circuits 2 to be described later.
When connected, the luminance signal of the S-VHS signal recording circuit 2 is input to the input terminal A via the connection point C, and the luminance signal of the VHS signal recording circuit 1 output from the low-pass filter 11 is input. This is a second switch that is input to the terminal b and outputs one of the luminance signals.

A luminance signal noise reduction (YNR) 12 enhances a vertical high-frequency component according to the signal level of the luminance signal output from the second switch during recording according to the signal level. , 13 are non-linear emphasis for enhancing the S / N by enhancing a high frequency component of the luminance signal output from the luminance signal noise reduction 12 according to the signal level, and SW3 is a luminance signal output from the non-linear emphasis 13 Are input to the input terminal A, the luminance signal output from the second switch is input to the input terminal B, and the third switch outputs one of the luminance signals.

Reference numeral 14 denotes a main emphasis for enhancing the S / N by emphasizing a high frequency component of the luminance signal output from the third switch irrespective of the signal level, and 15 denotes a luminance signal from the main emphasis 14. The white / dark clip circuit, which removes sharp spike signals at the rising and falling portions of the
The FM that modulates the luminance signal output from the white / dark clip circuit 15 and outputs the resulting signal as an FM-modulated luminance signal
M modulation circuit.

SW4 is connected to the S-VHS signal recording circuit 2 when it is connected to the S-VHS signal recording circuit 2 described later.
A fourth switch for inputting the color signal on the input side to the input terminal A via the connection point B, inputting the output signal from the automatic gain control circuit 10 to the input terminal B, and outputting one of the signals; Reference numeral 17 denotes a recording-system color signal processing circuit which receives a signal from the fourth switch, extracts only a frequency band including a color signal therein, and performs low-frequency conversion processing.

Reference numeral 18 denotes a first adder for adding the FM-modulated luminance signal input from the FM modulation circuit 16 and the low-frequency conversion color signal output from the recording-system color signal processing circuit 17 by frequency multiplexing. The recording signal output from the first adder 18 is compensated for a variation in frequency characteristics through a video head system by a recording current equalizer (not shown), and then amplified by a recording amplifier 19 to a signal level suitable for recording on a magnetic tape. Are recorded on a magnetic tape via a rotary transformer and a rotating magnetic head (not shown).

As described above, in the configuration of the VHS signal recording circuit 1, the composite video signal input from the input terminal InV is signal-processed and output from the recording amplifier 19.
When the signal recording circuit 1 is used alone, the first switch is fixed to the output terminal B side, the second switch and the fourth switch are both fixed to the input terminal B side, and the third switch is It is fixed to the terminal a side.

Therefore, the composite video signal input from the input terminal InV is output from the output terminal b of the first switch,
A low-pass filter 11, an input terminal b of the second switch,
The processing of the luminance signal is performed by the path connected by the luminance signal noise reduction 12, the non-linear emphasis 13, the input terminal A of the third switch, and the FM modulation circuit 16,
Input terminal b of the fourth switch, recording system color signal processing circuit 1
The color signal processing is performed by the path connected at 7.

Next, the S-VHS signal recording circuit 2 will be described. As described above, the S-VHS signal recording circuit 2
Although it is not possible to process video signals by itself,
By connecting to the VHS signal recording circuit 1 and using it,
-It enables signal processing of a video signal of the VHS format.

Here, the switch SW5 receives the luminance signal input through the input terminal InY and inputs it to the input terminal A.
When connected to the VHS signal recording circuit 1, the composite video signal is input to the input terminal B via the connection point A,
A fifth switch that outputs one of the signals, 50 is an automatic gain control circuit (AGC) that automatically adjusts a signal output from the fifth switch to an appropriate signal level, and 51 is a signal from the automatic gain control circuit 50. This is a Y / C separation circuit that separates and outputs a luminance signal and a chrominance signal included in the signal.

The SW 6 receives the luminance signal output from the Y / C separation circuit 51 at an input terminal A, and converts the luminance signal input from the input terminal InY through the automatic gain control circuit 50 into a Y / C separation signal. A sixth circuit which is directly input to the input terminal B without passing through the circuit 51 and outputs one of the signals
The switch 52 receives a signal from the sixth switch, and receives a 5M signal in accordance with the signal characteristics of the S-VHS format.
Low-pass filter (L
PF) and 53 are sub-emphasis for enhancing the high frequency component of the luminance signal output from the low-pass filter 52 and improving the S / N.

A low-pass filter (LPF) 54 receives a signal from the sixth switch and passes only a signal of 4 MHz or less in accordance with the signal characteristics of the VHS format, and a switch SW8 receives a luminance signal from the sub-emphasis 53. This is an eighth switch that receives the luminance signal from the low-pass filter 54 at the input terminal A and the luminance signal from the low-pass filter 54 at the input terminal B, and outputs one of the signals.

The SW 7 receives a color signal output from the Y / C separation circuit 51 at an input terminal A and a color signal input via an input terminal InC to an input terminal B. A seventh switch that outputs one signal.

Then, the S-VHS signal recording circuit 2
When connected to the S signal recording circuit 1, the composite video signal output from the output terminal A of the first switch in the VHS signal recording circuit 1 is supplied to the input terminal B of the fifth switch via the connection point A. Is entered. Also, the eighth
The luminance signal output from the switch is input to the input terminal A of the second switch in the VHS signal recording circuit 1 via the connection point C, and the color signal output from the seventh switch is output via the connection point B. VHS signal recording circuit 1
At the input terminal A of the fourth switch.

As described above, when the S-VHS signal recording circuit 2 is connected to the VHS signal recording circuit 1, the signal processing of the recording system of the S-VHS format video signal in addition to the VHS format video signal is performed. As for the input of a video signal, it is possible to cope with the input of a component video signal in which a luminance signal (Y signal) and a chrominance signal (C signal) are separated in addition to a composite video signal.

FIG. 2 shows that the S-VHS signal recording circuit 2
FIG. 3 is an explanatory diagram for explaining a switching state of each switch when used by connecting to the S signal recording circuit 1. Where VHS
Among the switches in the signal recording circuit 1 and the S-VHS signal recording circuit 2, the first switch is fixed to the output terminal A for supplying a signal to the S-VHS signal recording circuit 2, and the second switch and the The fourth switch is an S-VHS
In order to select a signal from the signal recording circuit 2, the signal is fixed to the input terminal A, and the third switch and the eighth switch are switched according to the format of the video signal to be subjected to signal processing. The switches 5 to 7 are switched according to the signal form of the input video signal.

The fifth to seventh switches will be further described with reference to FIG. 1. When the luminance signal and the chrominance signal are separated and input from the input terminals InY and InC, the fifth switch is The input terminal A, the sixth switch, and the seventh switch are both switched to the input terminal B.

Accordingly, the luminance signal input from the input terminal InY is output through a path connected by the input terminal A of the fifth switch, the automatic gain control circuit 50, and the input terminal B of the sixth switch. , The color signal input from the input terminal InC is output via the input terminal b of the seventh switch.

On the other hand, when a composite video signal is input via the input terminal InV, the fifth switch is switched to the input terminal B side, and both the sixth switch and the seventh switch are switched to the input terminal A side.

Therefore, the composite video signal input from the input terminal InV in the VHS signal recording circuit 1 is
Output terminal A of the first switch, connection point A, input terminal B of the fifth switch, automatic gain control circuit 50, Y / C
After the composite video signal is input through the path connected by the separation circuit 51 and the luminance signal and the chrominance signal are separated, the luminance signal is input to the sixth switch, and the chrominance signal is input to the seventh switch. Output via i.

To further explain the third switch and the eighth switch, when processing an S-VHS format video signal, the eighth switch is on the input terminal A side, and the third switch is on the input terminal low side. Side is switched to the second
Is fixed to the input terminal A side as described above.

Accordingly, the luminance signal output from the sixth switch is supplied to the low-pass filter 52 and the sub-emphasis 5
3, the input terminal A of the eighth switch, the connection point C, the input terminal A of the second switch, the input terminal B of the third switch, and the signal processing of the luminance signal through the path connected by the FM modulation circuit 16 The color signal output from the seventh switch is subjected to color signal processing through the connection point B, the input terminal A of the fourth switch, and the path connected by the recording system color signal processing circuit 17.

On the other hand, when processing a VHS format video signal, the eighth switch is switched to the input terminal B side, the third switch is switched to the input terminal A side, and the second switch is switched to the input terminal as described above. It is fixed to the i side.

Therefore, the luminance signal output from the sixth switch is output to the low-pass filter 54, the input terminal b of the eighth switch, the connection point C, the input terminal A of the second switch, the luminance signal noise reduction 12, the nonlinear signal The signal processing of the luminance signal is performed by the emphasis 13, the input terminal of the third switch A, and the path connected by the FM modulation circuit 16, and the color signal output from the seventh switch is connected to the connection point B, the fourth point. The signal processing of the color signal is performed by the input terminal A of the switch and the path connected by the recording system color signal processing circuit 17.

Then, the FM modulation luminance signal output from the FM modulation circuit 16 and the low-frequency conversion color signal output from the recording color signal processing circuit 17 are added by the first adder 18 by frequency multiplexing. Later, it is output from the recording amplifier 19 as a recording signal.

Thus, the input terminals InY, InC
VHS format signal processing and SV for the component video signal separated from the luminance signal and color signal input from
It has become possible to selectively perform HS format signal processing.

At this time, the composite video signal input from the input terminal InV has an automatic gain control circuit 10 and a low-pass filter in the VHS signal recording circuit 1 because the first switch is fixed to the output terminal A side. Since the second switch and the fourth switch are not input to the input terminal 11 and the second switch and the fourth switch are fixed to the input terminal A, the signal is processed by the automatic gain control circuit 50 and the low-pass filter 54 in the S-VHS signal recording circuit 2. The signal is selected.

Here, the low-pass filter 54 in the S-VHS signal recording circuit 2 is used at the time of VHS format signal processing, but has a slightly wider band than the low-pass filter 10 in the VHS signal recording circuit 1. It has become. This is because the input composite video signal has already been separated into a luminance signal and a chrominance signal by the Y / C separation circuit 51, so that the band does not need to be narrowed as much as the low-pass filter 11, and conversely, the band can be widened to increase the resolution. It is because it becomes possible to increase.

The S-VHS signal recording circuit 2 stores V
An automatic gain control circuit 50 is provided separately from the automatic gain control circuit 10 in the HS signal recording circuit 1 for the following reason.

The automatic gain control circuit 10 obtains a keyed pulse based on a synchronization signal obtained from a synchronization separation circuit (not shown) to which an output signal of a low-pass filter 11 provided at a subsequent stage is input, and performs gain control based on the keyed pulse. Is going. Further, the burst gate pulse generated based on the synchronization signal is required when the recording color signal processing circuit 17 performs color signal processing.

Here, the signal output from the automatic gain control circuit 10 without providing the automatic gain control circuit 50 is S-VHS
When the signal is processed by the Y / C separation circuit 51 in the signal recording circuit 2, the output signal is delayed by the processing time in the Y / C separation circuit 51. In particular, when the Y / C separation circuit 51 is constituted by a digital signal processing circuit, the delay time is large, and it is several μsec.

That is, the Y / C separation circuit 51, the input terminal A of the seventh switch, the connection point B, the input terminal A of the fourth switch, and the input via the path connected by the recording color signal processing circuit 17 are input. A phase shift occurs between the color signal and the burst gate pulse, and accurate color signal processing becomes difficult.

Therefore, in this embodiment, an automatic gain control circuit 50 is separately provided in the S-VHS signal recording circuit 2, and a keyed pulse is generated by a synchronous separation circuit (not shown) provided immediately after the S-VHS signal recording circuit 2, and the gain control is performed by the keyed pulse. The burst gate pulse input to the recording color signal processing circuit 17 is generated based on the signal output from the Y / C separation circuit 51.

With the above configuration, the VHS signal recording circuit 1 can perform signal processing of the recording system of the VHS format video signal, so that it can be used as a video signal processing circuit of a VTR compatible with the VHS format. S
When the VHS signal recording circuit 2 is connected to the VHS signal recording circuit 1, the signal processing of the recording system of the VHS format video signal can be performed in addition to the S-VHS format video signal. Can be used as a VTR video signal processing circuit.

Next, a reproduction system of the video signal processing circuit according to the embodiment of the present invention will be described with reference to FIG. As shown in FIG. 3, the reproduction system of the video signal processing circuit according to the embodiment of the present invention comprises a VHS signal reproduction circuit 3 and the VHS signal reproduction circuit 3.
And an S-VHS signal reproducing circuit 4 connected and used. When the VHS signal reproducing circuit 3 is used alone, signal processing of a reproducing system for a VHS format video signal can be performed. When the S-VHS signal reproduction circuit 4 is connected to the VHS signal reproduction circuit 3 and used, it is possible to perform signal processing of a reproduction system of an S-VHS format video signal in addition to a VHS format video signal. You can do it.

Here, the VHS signal reproducing circuit 3 will be described first. Reference numeral 20 denotes a reproduction amplifier for amplifying a reproduction signal reproduced from a magnetic tape (not shown) to a predetermined level, 21 an FM equalizer for compensating a frequency characteristic and a group delay characteristic of a tape head system, and SW9 an S-VH described later.
When connected to the S signal reproduction circuit 4, the reproduction signal of the S-VHS signal reproduction circuit 4 is input to the input terminal A via the connection point E, and the output signal from the FM equalizer 21 is input to the input terminal B. And a ninth switch that outputs one of the signals.

A double limiter 22 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. An FM demodulation circuit 23 demodulates a reproduced signal subjected to the limiter. Restores the high-frequency component emphasized by the main emphasis 14 at the time of recording,
/ N is a low-pass filter for removing a carrier wave contained in the luminance signal,
Reference numeral 6 denotes a non-linear de-emphasis for improving the S / N by restoring the high-frequency component emphasized by the non-linear emphasis 13 during recording.

The SW 10 receives the signal output from the main de-emphasis 24 at an input terminal A, receives the output signal from the non-linear de-emphasis 26 at an input terminal B, and outputs one of the signals. When connected to an S-VHS signal reproducing circuit 4 to be described later, the tenth switch SW11 inputs a luminance signal of the S-VHS reproducing circuit 4 to an input terminal A via a connection point G, The signal output from the switch is input to the input terminal b, and the first signal that outputs one of the signals
A first switch, 27 is a luminance signal noise reduction (YNR) for removing a noise component of the luminance signal output from the eleventh switch, and 28 is a noise canceller for removing a noise component distributed in a high range in the luminance signal. .

Reference numeral 29 denotes a reproduction color signal processing circuit which receives a reproduction signal from the reproduction amplifier 20 and performs high-frequency conversion processing. Reference numeral SW12 denotes a reproduction color signal output from the reproduction color signal processing circuit 29. And a twelfth switch for outputting a signal of one of the input terminals B, which is grounded in an AC manner and is in a non-input state. Reference numeral 30 denotes a reproduction luminance signal output from the noise canceller 28 and a twelfth switch. A second adder for adding the output signals of the twelve switches,
The SW 13 inputs a signal to an input terminal A via a connection point J when connected to an S-VHS signal reproduction circuit 4 to be described later, and a composite video signal output from the second adder 30 to an input terminal. A thirteenth switch which is input to the second terminal and outputs one of the signals, and the output signal of the thirteenth switch is output via the output terminal OutV.

With the above configuration, the reproduced signal reproduced from the magnetic tape is output through the output terminal OutV after signal processing, but when the VHS signal reproducing circuit 3 is used alone, the ninth signal is used. The switch to the eleventh switch and the thirteenth switch are both fixed to the input terminal B side,
The second switch is fixed to the input terminal A side.

Therefore, the reproduced signal reproduced from the magnetic tape is supplied to the FM equalizer 21, the input terminal B of the ninth switch, the low-pass filter 25, the non-linear de-emphasis 26, the input terminal B of the tenth switch, and the eleventh switch. The luminance signal is processed through the input terminal b and the path connected by the noise canceller 28, and the color signal is processed through the reproduction system color signal processing circuit 29 and the input terminal A of the twelfth switch.

Next, the S-VHS signal reproducing circuit 4 will be described. As described above, the S-VHS signal reproducing circuit 4
Although it is not possible to process video signals by itself,
By connecting and using the VHS signal reproduction circuit 3,
-It enables signal processing of a video signal of the VHS format.

Here, 55 is an S-VHS signal reproducing circuit 4
Is connected to the VHS signal reproduction circuit 3, a reproduction signal from the reproduction amplifier 20 is input through the connection point D,
This is an FM equalizer that compensates for the frequency characteristics and group delay characteristics of the tape head system in accordance with the signal characteristics of the S-VHS format. The output signal of the FM equalizer 55 is supplied to the input terminal A of the ninth switch via a connection point E. Is input to

Reference numeral 56 denotes a first point via the connection point F.
0, the signal output from the switch is input and S-VH
A low-pass filter 57 for removing a carrier wave included in the luminance signal in accordance with the signal characteristics of the S format. A sub-57 for improving the S / N by returning the high-frequency component emphasized by the sub-emphasis 53 at the time of recording is restored. The de-emphasis SW 14 receives an output from the sub-de-emphasis 57 at an input terminal A and a signal output from a tenth switch via a connection point F to an input terminal B. The output signal of the fourteenth switch is input to the input terminal A of the eleventh switch via the connection point G.

A signal 58 is generated when a signal output from the second adder 30 is input via a connection point H, a color signal component remaining in a reproduced luminance signal is removed, and a reproduced color signal is added. Comb filter that suppresses interference
Reference numeral 9 denotes a third adder for adding the reproduced luminance signal output from the comb filter 58 and the reproduced color signal output from the reproduction system color signal processing circuit 29 via the connection point I, and a third adder. The output signal of the switch 59 is input to the input terminal A of the thirteenth switch via the connection point J.

The luminance signal output from the comb filter 58 is output via an output terminal OutY, and the color signal output from the reproduction system color signal processing circuit 29 via a connection point I is output from an output terminal OutC. Is output via.

As described above, when the S-VHS signal reproducing circuit 4 is connected to the VHS signal reproducing circuit 3, signal processing of the reproducing system of the S-VHS format video signal in addition to the VHS format video signal is performed. As for the output of the video signal, it is possible to cope with the output of a component video signal in which a luminance signal and a chrominance signal are separated in addition to a composite video signal.

FIG. 4 shows that the S-VHS signal reproducing circuit 4
FIG. 9 is an explanatory diagram for explaining a switching state of each switch when used by connecting to the S signal reproduction circuit 3. Where VHS
Of the switches in the signal reproduction circuit 3 and the S-VHS signal reproduction circuit 4, the ninth switch, the tenth switch, and the fourteenth switch are switched according to the format of a video signal to be subjected to signal processing. The eleventh switch and the thirteenth switch are fixed to the input terminal A in order to select a signal from the S-VHS signal reproduction circuit 4,
Are fixed to the input terminal B side.

The ninth switch, the tenth switch, and the fourteenth switch will be further described with reference to FIG.
When processing an S-VHS format video signal,
The ninth switch, the tenth switch, and the fourteenth switch are all switched to the input terminal A side.
The first switch is fixed to the input terminal A side, and the twelfth switch is fixed to the input terminal B side.

Accordingly, the reproduction signal output from the reproduction amplifier 20 is supplied to the connection point D, the FM equalizer 55, the connection point E, the input terminal of the ninth switch, the main de-emphasis 24, and the input terminal of the tenth switch. , Connection point F, low-pass filter 56, sub-deemphasis 57, input terminal A of the fourteenth switch, connection point G, input terminal A of the eleventh switch, noise canceller 28, second adder 30, connection point H The processing of the luminance signal is performed by the path connected by the comb filter 58, and the processing of the color signal by the path connected by the reproduction system color signal processing circuit 29 and the connection point I.

On the other hand, when processing a video signal of the VHS format, the ninth switch, the tenth switch and the fourteenth switch are all switched to the input terminal B side, and as described above, the eleventh switch is switched to the input terminal. The twelfth switch is fixed to the input terminal B side, and the twelfth switch is fixed to the input terminal B side.

Therefore, the reproduction signal output from the reproduction amplifier 20 is supplied to the FM equalizer 21, the input terminal B of the ninth switch, the low-pass filter 25, the non-linear de-emphasis 26, the input terminal B of the tenth switch, and the connection point F. , The input terminal B of the fourteenth switch, the connection point G, the input terminal A of the eleventh switch, the noise canceller 28, the second adder 30, the connection point H, and the luminance signal through the path connected by the comb filter 58. Is performed, and the color signal processing is performed by the path connected by the reproduction system color signal processing circuit 29 and the connection point I.

The thirteenth switch is, as described above,
The output terminal OutY is fixed to the input terminal A, and the luminance signal is output from the output terminal OutY and the color signal is output from the output terminal OutC. At the same time, the composite video signal obtained by the addition by the third adder 59 is connected to the connection point. J, output from the output terminal OutV via the input terminal A of the thirteenth switch.

As described above, it is possible to selectively perform VHS format signal processing and S-VHS format signal processing on a reproduced signal reproduced from a magnetic tape.

At this time, the luminance signal output from the noise canceller 28 is output from the reproduction system color signal processing circuit 29 in the second adder 30 because the twelfth switch is fixed to the input terminal B side. The output reproduced color signals are output to the comb filter 58 without being added, and the reproduced color signals are added by the third adder 59.
Since the thirteenth switch is fixed to the input terminal A side, the composite signal added by the third adder 59 is output from the output terminal OutV.

At this time, since the composite signal output from the output terminal OutV adds the luminance signal passed through the comb filter 58 and the color signal input via the connection point I, moire occurs. No good reproduced signal can be obtained.

With the above configuration, the VHS signal reproducing circuit 3 can perform the signal processing of the reproducing system of the video signal of the VHS format, so that it can be used as a video signal processing circuit of a VTR compatible with the VHS format. S
When the VHS signal reproducing circuit 4 is connected to the VHS signal reproducing circuit 3, since the signal processing of the reproducing system of the VHS format video signal in addition to the S-VHS format video signal can be performed, the S-VHS format Can be used as a VTR video signal processing circuit.

[0068]

As described above, according to the present invention, VH
When the S signal recording circuit 1 or the VHS signal reproducing circuit 3 is used alone, only the signal processing of the video signal of the VHS format can be performed, and the S-VHS signal recording circuit 2 is replaced with the VHS signal recording circuit 1. And SV
When the HS signal reproducing circuit 4 is connected to the VHS signal reproducing circuit 3 and used, the signal processing of the S-VHS format video signal can be performed in addition to the VHS format video signal.

Therefore, V corresponding to the VHS format
TR and VTR compatible with S-VHS format
There is no need to mount different circuits, and the VHS signal recording circuit 1 and the VHS signal reproducing circuit 3 can be mounted on both VTRs in common. Therefore, the development cost can be greatly reduced, and the cost can be significantly reduced due to mass production effects. This has the effect that it can be suppressed.

The S-VHS signal recording circuit 2 and the S-VHS
Since it can be used as a signal processing circuit of a VTR compatible with the S-VHS format only by adding the VHS signal reproducing circuit 4, the signal processing circuit of the VTR compatible with the S-VHS format can be configured with a slight increase in cost. Play.

[Brief description of the drawings]

FIG. 1 is a block diagram for explaining a recording system of a video signal processing circuit according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram for explaining a switching state of each switch when the S-VHS signal recording circuit 2 is connected to the VHS signal recording circuit 1 and used.

FIG. 3 is a block diagram for explaining a reproduction system of the video signal processing circuit according to the embodiment of the present invention.

FIG. 4 is an explanatory diagram for explaining a switching state of each switch when the S-VHS signal reproducing circuit 4 is connected to the VHS signal reproducing circuit 3 and used;

[Explanation of symbols]

REFERENCE SIGNS LIST 1 VHS signal recording circuit 2 S-VHS signal recording circuit 3 VHS signal reproducing circuit 4 S-VHS signal reproducing circuit 10, 50 Automatic gain control circuit (AGC) 11, 25, 52, 54, 56 Low-pass Filter (L
PF) 12, 27 Luminance signal noise reduction (YNR) 13 Non-linear emphasis 14 Main emphasis 15 White / dark clip circuit 16 FM modulation circuit 17 Recording color signal processing circuit 18 First adder 19 Recording amplifier 20 ... Reproduction amplifier 21, 55 ... FM equalizer 22 ... Double limiter 23 ... FM demodulation circuit 24 ... Main de-emphasis 26 ... Non-linear de-emphasis 28 ... Noise canceller 29 ... Reproduction system color signal processing circuit 30 ... Second adder 51 Y / C separation circuit 53 Sub-emphasis 57 Sub-emphasis 58 Comb filter 59 Third adder InY Luminance signal input terminal InC Color signal input terminal InV Composite signal input terminal OutY Luminance signal Output terminal OutC: color signal output Terminal OutV ... composite signal output terminal SW1 to SW14 ... switch A to J ... connection point

Claims (4)

[Claims] 1. A recording system luminance signal processing section for performing recording system signal processing on a luminance signal included in an input composite signal, and recording system signal processing on a color signal included in the composite signal. A video signal processing circuit for outputting a recording signal in a signal format of a standard format, the video signal processing circuit comprising: A high-quality signal processing circuit for obtaining a recording signal in a signal format of a high-quality format in which the video signal processing circuit is enlarged can be connected, and the video signal processing circuit alone can output only a recording signal in the signal format of the standard format. When a high-quality signal processing circuit is connected to the video signal processing circuit, the video signal processing circuit is shared so that the standard format is used. A video signal processing circuit capable of outputting a recording signal by the signal form of the recording signal and the high-quality format by the signal form selectively. 2. The video signal processing circuit alone can be used as a recording system video signal processing circuit of a magnetic recording device compatible with the standard format, and when the high image quality signal processing circuit is connected to the video signal processing circuit. 2. The video signal processing circuit according to claim 1, wherein the video signal processing circuit can be used as a recording system video signal processing circuit of a magnetic recording apparatus compatible with the high image quality format. 3. A reproduction-system luminance signal processing unit for performing a reproduction-system signal processing on a luminance signal included in a standard-format signal reproduced from a magnetic tape, and a color signal included in the reproduction signal. A video signal processing circuit for outputting a reproduced composite signal, wherein the video signal processing circuit compares the reproduced signal with a reproduced signal in the signal format of the standard format. A high quality signal processing circuit for reproducing a reproduction signal in a signal format of a high image quality format in which a signal band is expanded can be connected. The video signal processing circuit alone reproduces only a reproduction signal in a signal format of the standard format. When the high image quality signal processing circuit is connected to the video signal processing circuit, the video signal processing circuit can be shared. A video signal processing circuit capable of reproducing a reproduction signal by the signal form of the reproduction signal and the quality format by the signal form of the standard formats selectively. 4. The video signal processing circuit alone can be used as a reproduction-system video signal processing circuit of a magnetic recording device compatible with the standard format, wherein the high-quality signal processing circuit is connected to the video signal processing circuit. 4. The video signal processing circuit according to claim 3, wherein the video signal processing circuit can be used as a reproduction system video signal processing circuit of a magnetic reproduction apparatus compatible with the high image quality format.