JPH0537801A - High definition television receiver - Google Patents

Abstract

PURPOSE:To receive television signals whose standards are different and to apply speed modulation typed contour emphasis to them. CONSTITUTION:Both high definition television signal and an existing television signal are received, the existing television signal is given to aspect ratio conversion circuits 5, 6, in which the aspect ratio is converted and the result is displayed on a screen the high frequency component of the luminance signal is extracted by high pass filter circuits 23, 24, 25 having a filter band corresponding to each television signal, the scanning speed of the electron beam is modulated to implement contour emphasis, and simultaneously a time delay of the deflection system attended with the speed modulation type contour emphasis is compensated by delaying the relevant television signal by a prescribed time at delay circuits 27, 28, 29 provided to a video signal output system respectively to apply proper contour emphasis employing speed modulation to the television signals whose standards differ from each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-definition television receiver which receives television signals of different standards and applies velocity modulation type contour enhancement to each of them.

[0002]

2. Description of the Related Art A high-definition television receiver (HDT), which is expected to grow as a next-generation television receiver that replaces the currently prevailing television receivers such as the NTSC system.
The V receiver) has 1125 scanning lines, and the aspect ratio of the screen is 16: 9. In addition, such a high-definition television receiver, which is expected to become popular in the near future, is a signal of the current television standard system such as NTS.
It is expected that they will appear in a form having compatibility, that is, compatibility, so that C-type television signals and the like can be received.

A high-definition television receiver 1 shown in FIG.
Includes a BS tuner 2 connected to an antenna 2a installed toward a satellite and a U / V tuner 3 connected to an antenna 3a for terrestrial broadcast waves. The BS tuner 2 has a MUSE required for receiving high-definition broadcasting.
A decoder 17 is connected, and the MUSE decoder 17 has a selector switch 18 for switching the HDTV input terminal 18a for HDTV baseband signals.
Is connected. On the other hand, the BS tuner 2 and the U / V tuner 3 are connected with a changeover switch 19 for changing over the respective channel selection outputs of ordinary satellite broadcasting and terrestrial broadcasting. Further, the changeover switch 19 has an NTSC input terminal. A changeover switch 20 for switching between the NTSC baseband signal supplied to 20a and the channel selection output is connected. Further, two aspect ratio conversion circuits 5 and 6 are connected in parallel to the changeover switch 20 via the scanning line number conversion circuit 4, and horizontal scanning is 525 lines and 2 to 1 interlace is 525 lines and 1. After converting to 1-to-1 non-interlace, the aspect ratio can be changed in two ways.

In the case of this example, the aspect ratio conversion circuit 5 is
Operates when conversion mode 1 is specified, in which the entire image of the current television signal of 4 to 3 is compressed to 3/4 times and the space is left on both sides to fit the screen of 16 to 9 and the aspect ratio is specified. The conversion circuit 6 cuts the upper and lower parts of the entire image of the current television signal of 4 to 3 to 3/4 times in the vertical direction, and
It operates when the conversion mode 2 for fitting in a 6 to 9 screen is designated. Here, 2 corresponding to the conversion modes 1 and 2 of the high definition television signal and the current television signal.
A three-input one-output type changeover switch 7 is connected to the changeover switch 18 and the aspect ratio conversion circuits 5 and 6 so that a total of three signals can be selectively displayed on the screen. The television signal selected by the changeover switch 7 is sent to the video processing / output circuit 9 via the delay circuit 8, and the video signal is subjected to predetermined signal processing and then 1
It is applied to the cathode of a high-definition picture tube 10 having an aspect ratio of 6: 9.

By the way, the high-definition television receiver 1 shown in this example has a built-in speed modulation type edge enhancement circuit 11 for performing edge enhancement by utilizing horizontal deflection, and an electronic component is used at a portion where a luminance signal changes. The horizontal scanning speed of the beam is changed to enhance the contour. That is, the luminance signal included in the output of the changeover switch 7 is guided to the high-pass filtering circuit 12, where the contour component of the image is extracted. Next, after the extracted contour component is amplified by the amplifier circuit 13, the noise component is removed by limiting the amplitude in the limiter circuit 14. Finally, the high frequency component from which the noise component has been removed is sent to the coil drive circuit 15, and from there, a drive current is supplied to the velocity modulation coil 16 incorporated as an auxiliary coil in the deflection yoke. For this reason, the horizontal scanning speed of the electron beam changes in the changing portion of the luminance signal corresponding to the contour of the image, and the screen becomes darker as the deflection speed of the electron beam becomes faster, and conversely the screen becomes brighter as the deflection speed becomes slower. so,
The apparent brightness changes to enhance the contour.

[0006]

In the conventional high-definition television receiver 1 described above, since the frequency bands of the contour components included in the three types of television signals are different, the velocity modulation type is applied to all three types of television signals. If it is desired to perform the contour enhancement processing of, it is necessary to switch the filtering band of the high-pass filtering circuit 12 as a matter of course. High definition television signals
It has a signal band originally extending to 30 MHz, and even the one decoded through the Muse decoder has a signal band of 20 MHz. On the other hand, the current television signal is
In conversion mode 2 in which neither compression nor expansion is performed, 12 MHz due to conversion of scanning linear velocity, and 4/3 in conversion mode 1
There is a considerable gap in the signal band between the high-definition television signal and the doubled 16 MHz. Therefore, the high-pass filtering circuit 12
The filtering band of is different for each of the three types of television signals, but in this example, it is considered that contour enhancement processing by velocity modulation should be applied only to high-definition television signals. By adjusting the delay time in the delay circuit 8 in the video signal output system against the operation time delay generated in the contour emphasis circuit 11 connecting the high filtering circuit 12 to the coil drive circuit 15, the velocity modulation is performed in the contour portion of the image. The timing was adjusted as described above. Therefore, when it is desired to perform contour enhancement processing by speed modulation on the current television signal, it is necessary to switch the filtering band of the high-pass filtering circuit 12 and adjust the delay time of the delay circuit 8 at the same time. With the circuit configuration as it is, there is a problem that there is no measure unless special improvements are made with specialized knowledge, and such improvements are beyond the control of general users.

[0007]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and receives both a high-definition television signal and a current television signal, and an aspect ratio conversion circuit for the current television signal. In a high-definition television receiver that converts the aspect ratio and displays it on the screen, it is provided corresponding to each of the television signals, the high frequency component of the luminance signal is extracted, and the horizontal scanning speed of the electron beam is modulated. The present invention is characterized by comprising a speed modulation type contour emphasizing means for emphasizing a contour, and a delay means for compensating an operation time delay of the contour emphasizing circuit by delaying a corresponding television signal by a predetermined time. Is.

[0008]

The present invention receives both a high-definition television signal and a current television signal, and the aspect ratio conversion circuit converts the aspect ratio of the current television signal and displays it on the screen. The edge enhancement means provided corresponding to the John signal extracts the high-frequency component of the luminance signal and modulates the horizontal scanning speed of the electron beam to enhance the edge. At the same time, the operation time delay of the edge enhancement means can be adjusted by the corresponding television. Each of the television signals is delayed by a predetermined time for compensation, and the television signals of different standards are subjected to proper contour enhancement by speed modulation.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIG. FIG. 1 is a circuit configuration diagram showing an embodiment of a high-definition television receiver of the present invention.

The high definition television receiver 21 shown in FIG.
The HDTV includes three types of high-pass filtering circuits 23, 24, and 25 provided in the edge enhancement circuit 22 so that edge enhancement processing can be performed on each of the three types of television signals.
Connect to input terminal 2 and aspect ratio conversion circuits 5 and 6 and
These 3 are connected via the input / output 1 type changeover switch 26.
The high-pass filtering circuits 23, 24, and 25 of various kinds are connected to the amplifier circuit 13.
Connected to. Furthermore, the delay circuits 27 and 2 having predetermined delay times corresponding to three types of television signals are provided in order to compensate for the operation time delay that occurs during the contour enhancement process.
8 and 29 are connected in the middle of the line from the changeover switch 18 and the aspect ratio conversion circuits 5 and 6 to the changeover switch 7.

The delay times of the delay circuits 27, 28 and 29 are
ΤH, τN1, and τN2, respectively, which are defined by the following relational expressions. [tau] H = [tau] Hf + [tau] R- [tau] V [tau] N1 = [tau] N1f + [tau] R- [tau] V [tau] N2 = [tau] N2f + [tau] R- [tau] V where [tau] Hf, [tau] N1f and [tau] N2f are signal delay times in the high-pass filtering circuits 23, 24, and 25, respectively. Further, τR is a signal delay time generated in the deflection system from the changeover switch 26 to the velocity modulation coil 16,
τV is from the changeover switch 7 to the high-definition picture tube 1
This is a signal delay time that occurs in the video signal output system up to the cathode of 0. It should be noted that when these three formulas are modified, τH + τV = τHf + τR τN1 + τV = τN1f + τR τN2 + τV = τN2f + τR is obtained, as is apparent from the above, the total signal delay time (value on the left side of the equation) generated in the video signal output system.
It can be seen that is designed so as to match the total signal delay time (value on the right side in the equation) that occurs in the deflection system.

The changeover switches 7 and 26 are changed over in response to a changeover control signal from the outside. Therefore, when a high-definition television signal is received, a delay circuit 27 having a delay time τH is provided in response to the high-pass filtering circuit 23 being connected to the changeover switch 26.
Is connected to the changeover switch 7. Further, when the current television signal subjected to the aspect ratio conversion in the conversion mode 1 is received, the delay circuit having the delay time τN1 in response to the high-pass filtering circuit 24 being connected to the changeover switch 26. 28 is connected to the changeover switch 7.
Furthermore, when the current television signal subjected to the aspect ratio conversion in the conversion mode 2 is received, the delay having the delay time τN2 is provided in response to the high-pass filtering circuit 25 being connected to the changeover switch 26. The circuit 29 is connected to the changeover switch 7. Therefore, regardless of which of the three types of television signals is received, optimum velocity modulation suitable for each signal can be performed, and appropriate contour enhancement can be performed by delay time compensation according to the velocity modulation.

As described above, the high-definition television receiver 21 receives both the high-definition television signal and the current television signal, and the aspect ratio conversion circuits 5, 6 for the current television signal. The aspect ratio is converted and displayed on the screen, and high-pass filtering circuits 23, 24 having a filtering band corresponding to each television signal are displayed.
The high frequency component of the luminance signal is extracted at 25, the horizontal scanning speed of the electron beam is modulated to enhance the contour, and at the same time, the time delay of the deflection system due to the velocity modulation type contour enhancement is provided in the video signal output system. The delay circuits 27, 28, and 29 are configured to compensate the corresponding television signals by delaying them for a predetermined time respectively, so that appropriate contour enhancement can be performed on both the high-definition television signal and the current television signal. It is possible to display a high-definition television signal and a current television signal on the screen of the high-definition picture tube 10 having an aspect ratio of 16: 9 with excellent image quality.

[0014]

As described above, according to the present invention, both the high-definition television signal and the current television signal are received, and the aspect ratio conversion circuit converts the aspect ratio of the current television signal. Is displayed on the screen, and the high-frequency component of the luminance signal is extracted with the filtering band corresponding to each television signal, the horizontal scanning speed of the electron beam is modulated to enhance the contour, and at the same time, with the speed modulation type contour enhancement. Since the time delay of the deflection system is compensated by delaying the corresponding television signal in the video signal system by a predetermined time, the contours suitable for both the high-definition television signal and the current television signal are properly contoured. It is possible to emphasize, and the high-definition television signal and the current television signal are excellently displayed on the screen having an aspect ratio of 16: 9. An excellent effect such as can be displayed with a quality.

[Brief description of drawings]

FIG. 1 is a circuit configuration diagram showing an embodiment of a high-definition television receiver of the present invention.

FIG. 2 is a circuit configuration diagram showing an example of a conventional high-definition television receiver.

[Explanation of symbols]

 5, 6 Aspect ratio conversion circuit 7 Changeover switch 10 High-definition picture tube 21 High-definition television receiver 22 Contour enhancement means (contour enhancement circuit) 23, 24, 25 High-pass filtering circuit 26 Changeover switch 27, 28, 29 Delay means ( Delay circuit)

Claims (1)

Claim: What is claimed is: 1. A high-definition television signal and a current television signal are both received, and an aspect ratio conversion circuit converts the aspect ratio of the current television signal and displays it on the screen. In high definition television receivers,
Velocity modulation type contour emphasizing means which is provided corresponding to each of the television signals and extracts the high frequency component of the luminance signal to modulate the horizontal scanning speed of the electron beam to enhance the contour, and the operating time of the contour emphasizing means. A high-definition television receiver, comprising: delay means for compensating the delay by delaying a corresponding television signal by a predetermined time.