JPH07131734A - Television receiver and on-screen signal generator - Google Patents

Abstract

PURPOSE:To eliminate distortion of an on-screen picture when a video image whose aspect ratio is 4:3 is displayed on the entire display screen whose aspect ratio is 16:9 while the display size of the video image in the horizontal direction is magnified closer to left and right edges relatively with respect to a middle part in the horizontal direction. CONSTITUTION:An on-screen picture outputted from a character generator 1 is written in a VRAM 2 and one line of the picture is inputted to a shift register 4. The shift register 4 decomposes the picture in the unit of picture elements based on a reference clock received from a reference signal generator 6 to provide an output of an on-screen signal. A parabolic waveform generating circuit 61 generates a parabolic waveform signal, and a VCO 62 outputs a reference clock whose frequency is higher at both edges in the horizontal direction and whose frequency is lower in the middle. Thus, the displayed size of the on-screen picture is reduced relatively toward the left and right edges with respect to the middle part in the horizontal direction and then distortion is cancelled.

Description

Detailed Description of the Invention

[0001]

The present invention has an aspect ratio of 16: 9.
Display screen, and the display screen has an aspect ratio of 4: 3.
When the image is displayed, the display size in the horizontal direction is enlarged as it approaches the left and right edges relatively to the horizontal center of the display screen, thereby displaying the image with the aspect ratio of 4: 3 on the entire display screen. The present invention relates to a television receiver provided with a non-linear processing circuit, and an on-screen signal generator suitable for use in such a television receiver.

[0002]

2. Description of the Related Art Recently, an image with an aspect ratio of 16: 9 has been introduced which is more realistic than the conventional image with an aspect ratio of 4: 3, such as high-definition broadcasting. Television receivers having a display screen with a ratio of 16: 9 have been commercialized and are becoming popular. A television receiver having a display screen with an aspect ratio of 16: 9 can display a video signal with an aspect ratio of 16: 9,
Displaying a conventional video signal having an aspect ratio of 4: 3 is performed. Thus, the aspect ratio is 1
With the advent of 6: 9 video, it has become possible to display video having an aspect ratio different from that of the display screen of a television receiver.

As a display method for displaying a video signal having an aspect ratio of 4: 3 on a television receiver having a display screen having an aspect ratio of 16: 9, the aspect ratio is 4: 3.
Aspect ratio 1 by compressing the video signal of
Mode to display in the horizontal center part of the display screen of 6: 9,
A mode in which the aspect ratio 16: 9 at the central portion in the vertical direction in the aspect ratio 4: 3 image signal is enlarged and displayed, and the aspect ratio 4: 3 image signal is horizontally extended as it is to the aspect ratio 16: 9 display screen. There are modes such as displaying. As another mode, the present applicant has previously proposed that when a video image with an aspect ratio of 4: 3 is displayed on the display screen of a television receiver having a display screen with an aspect ratio of 16: 9 according to Japanese Patent Application No. 4-258571. In addition, by expanding the horizontal display size toward the left and right edges relatively to the horizontal center of the display screen, an image with an aspect ratio of 4: 3 is displayed on the entire display screen with an aspect ratio of 16: 9. Suggested a way to display.

In this new display method, the display size in the horizontal direction is enlarged as it approaches the left and right end portions relative to the horizontal center portion of the display screen. This display method is called non-linear processing. According to such non-linear processing, as can be seen from the display example of the monoscope signal shown in FIG. 10, a distorted image is formed at the left and right edges of the display screen, but the circularity of the image is rounded at the center of the display screen. To be kept. Therefore, the aspect ratio is 4: 3.
The video can be displayed on the entire display screen with an aspect ratio of 16: 9 without any discomfort to the viewer, and the wide aspect ratio of 16: 9 can be fully utilized. It becomes possible to display. As means for realizing this non-linear processing, there are a deflection circuit and a digital signal processing as described in the above-mentioned prior application.

On the other hand, conventionally, information different from the video that comes in as a television signal and is displayed on the display screen, for example, character information indicating the operating state of the television receiver, is superimposed and displayed on the video. On-screen display is being performed. An example of the on-screen signal generator for generating such an on-screen signal is shown in FIG.
It is configured as shown in FIG. In FIG. 11, a character generator 1 generates data of characters (including figures) to be displayed as an on-screen image, and as shown in FIG.
Write to 2. As can be seen from FIG. 12, one pixel of the on-screen character corresponds to one bit in the VRAM2.

The counter 3 is supplied with the synchronizing signal of the video signal displayed on the display screen and the reference clock output from the reference signal generator 5, and the reference clock is divided and displayed according to the synchronizing signal. A row selection signal corresponding to the position of the scan line to be supplied is supplied to the VRAM 2. Then, the VRAM 2 inputs one line (line) of on-screen characters to the shift register 4 in response to a line selection signal input from the counter 3. The shift register 4 decomposes the image into one pixel according to the reference clock input from the reference signal generator 5 and outputs it as an on-screen signal. Since one pulse of the reference clock corresponds to one pixel of the on-screen character, the reference clock output from the reference signal generator 5 is shown in FIG.
When the clock has a constant frequency as shown in FIG. 13B, the shift register 4 outputs characters as shown in FIG. Therefore, the image shown in FIG. 14 is superimposed on the video by the on-screen signal generator.

[0007]

FIG. 11 shows a non-linear processing circuit for expanding the horizontal display size as it approaches the left and right end portions relatively to the horizontal center portion of the display screen as described above. Consider a television receiver equipped with both such an on-screen signal generator. FIG. 15 is a block diagram showing an example of this type of television receiver, and its configuration and operation will be described.

In FIG. 15, the incoming video signal is input to the video chroma processing circuit 101 and the sync separation circuit 102. The sync signal separated by the sync separation circuit 102 is applied to the deflection circuit 103 and the on-screen signal generator 10.
4 is input. This on-screen signal generator 10
4 is configured as shown in FIG. The on-screen signal output from the on-screen signal generator 104 is input to the combining processing circuit 105, and is processed by the video chroma processing circuit 101 to be combined with the output video signal. As a result, the video signal on which the on-screen image (character) is superimposed passes through the non-linear processing circuit 106 and has a cathode ray tube (CRT) 10 having a display screen with an aspect ratio of 16: 9.
Input to 7. Then, the video signal which is deflected by the deflection circuit 103 and on which the on-screen image is superimposed is displayed on the CRT 107.

In such a television receiver,
When the incoming video signal has an aspect ratio of 4: 3 and the non-linear processing circuit 106 is operated to display an image with an aspect ratio of 4: 3 on the entire display screen with an aspect ratio of 16: 9, an on-screen image is displayed. When superposed, as shown in FIG. 16, the left and right ends of the on-screen characters are enlarged. Since the processing by the non-linear processing circuit 106 enlarges the display size in the horizontal direction as it approaches the left and right end portions relative to the horizontal center portion as described above,
Although there is almost no discomfort in a normal image, there is a problem in that in the case of character information such as an on-screen image, the horizontal enlargement of the left and right ends is conspicuous, which may cause discomfort.

Such a problem is not limited to the on-screen characters indicating the operating state of the television receiver, and is the same for the character information generated and superimposed by the caption decoder and the character information transmitted by the character broadcast. is there. Furthermore, in software such as Western movies, subtitles may be inserted at the bottom of the display screen. This subtitle is also an on-screen image, and the subtitle has the same problem.

The present invention has been made in view of the above problems, and has a display screen having an aspect ratio of 16: 9,
When an image having an aspect ratio of 4: 3 is displayed on the display screen, the display size in the horizontal direction is enlarged as the display screen is closer to the left and right ends relative to the horizontal center of the display screen. It is an object of the present invention to provide a television receiver and an on-screen signal generator that can display an on-screen image without distortion even when the image of (1) is displayed on the entire display screen.

[0012]

In order to solve the above-mentioned problems of the prior art, the present invention provides (1) an aspect ratio of 1
A display screen of 6: 9 and an aspect ratio of 4: on the display screen.
When displaying the image of No. 3, the image having the aspect ratio of 4: 3 is enlarged by enlarging the display size in the horizontal direction as it approaches the left and right ends relatively to the horizontal center of the display screen. In a television receiver including a non-linear processing circuit for displaying the entire screen, and an on-screen signal generator for superimposing an on-screen image different from the video on the display screen, the display size of the on-screen image is changed. (EN) Provided is a television receiver characterized in that means for reducing the left and right end portions relative to the horizontal center portion of the display screen is provided, and (2) What is the image displayed on the display screen? An on-screen signal generator for generating an on-screen signal for superimposing another on-screen image on the video, An on-screen signal generating device is provided, which is provided with means for reducing the display size of the display image toward the left and right end portions relative to the horizontal center portion of the display screen. 1
A display screen of 6: 9 and an aspect ratio of 4: on the display screen.
When displaying the image of No. 3, the image having the aspect ratio of 4: 3 is enlarged by enlarging the display size in the horizontal direction as it approaches the left and right ends relatively to the horizontal center of the display screen. In a television receiver including a non-linear processing circuit for displaying the whole and a caption moving circuit for extracting a caption component included in the video, a display size of the caption component extracted by the caption moving circuit is displayed on the display screen. The present invention provides a television receiver characterized in that means is provided for reducing the width toward the left and right end portions relative to the horizontal center portion.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A television receiver and an on-screen signal generator according to the present invention will be described below with reference to the accompanying drawings. 1 is a block diagram showing an embodiment of an on-screen signal generator of the present invention, FIG. 2 is a waveform diagram for explaining the operation of the on-screen signal generator of the present invention, and FIG. 3 is an on-screen signal of the present invention. FIG. 4 is a diagram for explaining the operation of the generator, FIG. 4 is a diagram showing an on-screen image output from the on-screen signal generator of the present invention, and FIG.
Is a block diagram showing an embodiment of the television receiver of the present invention, FIG. 6 is a diagram for explaining the operation of the television receiver of the present invention, and FIG. 7 is a television of the present invention equipped with a subtitle moving circuit. 8 is a block diagram showing a receiver, FIG. 8 is a block diagram showing a concrete configuration of the caption moving circuit 109 in FIG. 7, and FIG.
FIG. 6 is a diagram for explaining the operation of the television receiver of the present invention including a caption moving circuit. In addition, in FIG.
The same parts as those in FIG. 11 are designated by the same reference numerals, and, in FIG. 5, the same parts as those in FIG. 15 are designated by the same reference numerals.

In FIG. 1, a character generator 1 generates data of characters (including figures) to be displayed as an on-screen image, and as described above with reference to FIG. 12, video data is generated as pattern data in dot units. Ram (VRAM) 2
Write in. As can be seen from FIG. 12, one pixel of the on-screen character corresponds to one bit in the VRAM2. The counter 3 is supplied with the synchronizing signal of the video signal displayed on the display screen and the reference clock output from the reference signal generator 6 of the present invention. The reference clock is divided and displayed according to the synchronizing signal. A row selection signal corresponding to the position of the scan line to be supplied is supplied to the VRAM 2. Then, the VRAM 2 inputs one line (line) of on-screen characters to the shift register 4 in response to a line selection signal input from the counter 3. The shift register 4 decomposes an image into one pixel according to the reference clock input from the reference signal generator 6 and outputs it as an on-screen signal.

The reference signal generator 6 will now be described. The reference signal generator 6 includes a parabolic waveform generation circuit 61 and a VCO (voltage controlled oscillator) 62. The parabolic waveform generation circuit 61 has a counter 3 shown in FIG.
2 is input, and the parabolic waveform generation circuit 61 generates a parabolic waveform signal as shown in FIG. 2C for each scanning line by the row start signal. As can be seen from FIG. 2C, this parabolic waveform signal is a waveform in which the voltage is high at both ends of one horizontal period (1H) and low at the middle. The parabolic waveform signal is input to the VCO 62, and the VCO 62 outputs a high frequency clock at a high voltage and a low frequency clock at a low voltage. Therefore, the VCO 62 supplies to the counter 3 and the shift register 4 a reference clock having a high frequency at both ends of 1H and a low frequency at an intermediate part as shown in FIG. 2B. Since the length of one pixel of the on-screen image is the length of the reference clock, the on-screen image on the display screen is shown in FIG.
As shown in, the left and right ends are reduced.

Conventionally, the reference clock is as shown in FIG.
Since the clock has a constant frequency as shown in (B), the characters shown in FIG. 3 (A) were output from the shift register 4, but in the on-screen signal generator of the present invention shown in FIG. Since the reference clock output from the reference signal generator 6 is a clock having a high frequency at both ends of 1H and a low frequency at an intermediate portion, as shown in FIG. Characters in which the left and right end portions are horizontally reduced and the middle portion is horizontally enlarged are output as shown in D). Therefore, the image as shown in FIG. 4 is superimposed on the video by the on-screen signal generator of the present invention.

FIG. 5 shows the structure of a television receiver including the on-screen signal generator of the present invention as shown in FIG. The incoming video signal in FIG. 5 is input to the video chroma processing circuit 101 and the sync separation circuit 102. The sync signal separated by the sync separation circuit 102 is input to the deflection circuit 103 and the on-screen signal generator 108. The on-screen signal generator 108 is constructed as shown in FIG. The on-screen signal output from the on-screen signal generator 108 is input to the combining processing circuit 105, and is processed by the video chroma processing circuit 101 to be combined with the output video signal. As a result, the video signal on which the on-screen image (character) is superimposed passes through the non-linear processing circuit 106, and the cathode ray tube (CRT) 1 having a display screen with an aspect ratio of 16: 9.
It is input to 07. Then, the video signal which is deflected by the deflection circuit 103 and on which the on-screen image is superimposed is displayed on the CRT 107.

In the television receiver of the present invention having the above-described structure, the aspect ratio of the incoming video signal is 4: 3, and the non-linear processing circuit 106 is operated to output the video with the aspect ratio of 4: 3. When displayed on the entire 16: 9 display screen, even if the on-screen image (character) is superimposed, the left and right end portions of the on-screen character are reduced and the middle portion is enlarged. In addition, all characters are displayed in substantially the same size without enlarging the left and right ends of the on-screen characters.

In the above description, the on-screen characters indicating the operating state of the television receiver have been described as the on-screen image, but the subtitles inserted into the display screen can also be subtitles without distortion using the principle of the present invention. Can be displayed.

FIG. 7 shows the structure of a television receiver having a subtitle moving circuit. The incoming video signal in FIG. 7 is input to the video chroma processing circuit 101 and the sync separation circuit 102. The sync signal separated by the sync separation circuit 102 is the deflection circuit 103 and the caption moving circuit 1.
09 is input. The configuration and operation of the subtitle moving circuit 109 will be described later. The caption signal output from the caption moving circuit 109 is input to the synthesizing processing circuit 105, and is processed by the video chroma processing circuit 101 to be combined with the output video signal. As a result, the video signal on which the caption is newly superimposed passes through the non-linear processing circuit 106 and the cathode ray tube (CRT) 10 having a display screen with an aspect ratio of 16: 9.
Input to 7. Then, the video signal that is deflected by the deflection circuit 103 and the caption is superimposed on the CRT 107 is displayed.

Here, the configuration and operation of the subtitle moving circuit 109 will be described. The basic configuration of the subtitle moving circuit 109 is well known (for example, Japanese Patent Application No. 4-18857).
No. 5), only the schematic configuration of the caption moving circuit 109 is shown here, and the main points of the present invention are mainly described. Subtitle moving circuit 10
As shown in FIG. 8, reference numeral 9 denotes a circuit for extracting a caption from a video signal, which includes a level comparator 11, an A / D converter 12, a field memory 13, and a D / A converter 14, and generating a caption signal, and a counter. 15, parabolic waveform generation circuit 16,
The VCO 17 is composed of a circuit for horizontally reducing the left and right end portions of the extracted subtitle in 1H and enlarging the middle portion thereof in the horizontal direction.

In FIG. 8, the level comparator 11 extracts a subtitle portion which is a white character portion by comparing the video signal with a predetermined level. The A / D converter 12 A / D-converts the subtitle component output from the level comparator 11 and inputs the subtitle component to the field memory 13. The field memory 13 writes the subtitle component by the write clock Swt of, for example, 4fsc output from the reference signal generator 18. on the other hand,
The counter 15 receives the sync signal of the video signal output from the sync separation circuit 102.
A row start signal similar to that shown in (D) is input to the parabolic waveform generation circuit 16. The parabolic waveform generation circuit 16 generates a parabolic waveform signal similar to that shown in FIG. 2C for each scanning line by the row start signal. This parabolic waveform signal has a high voltage at both ends of 1H and a low voltage at an intermediate part. The parabolic waveform signal is input to the VCO 17, and the VCO 17 outputs a high frequency clock at a high voltage and a low frequency clock at a low voltage. Therefore, the VCO 17 is 1H, which is similar to that shown in FIG.
A reference clock whose frequency is high at both ends and low in the middle is supplied to the field memory 13 as a read clock Srt.

Since the character component written in the field memory 13 is read by the read clock Srt having a high frequency at both ends of 1H and a low frequency at an intermediate part, the left and right ends of the subtitle output from the field memory 13 are reduced. The characters are enlarged in the middle part. The read subtitle component is D / A converted by the D / A converter 14, input to the combining circuit 15 in FIG. 7, processed by the video chroma processing circuit 101, and combined with the output video signal. .

As shown in FIG. 9A, a video signal having an aspect ratio of 4: 3 with subtitles inserted therein comes in, and the non-linear processing circuit 106 is operated to change the aspect ratio of the video of 4: 3. When it is displayed on the entire display screen with a ratio of 16: 9, the left and right ends of the subtitle are enlarged as shown in FIG. 9B in the related art, but a book provided with the subtitle moving circuit configured as described above. In the television receiver of the invention, all the characters are displayed in substantially the same size without enlarging the left and right ends of the subtitle as shown in FIG. 9C.

In the television receiver of the present invention shown in FIGS. 5 and 7 described above, the nonlinear processing circuit 106 is used.
Although the non-linear processing is realized by the digital signal processing by the above, it is needless to say that the non-linear processing may be realized by the deflection circuit 103 as described above. As described above, the present invention is not limited to the present embodiment described above, and various modifications can be made without departing from the gist of the present invention.

[0026]

As described in detail above, the television receiver and the on-screen signal generator of the present invention include:
Since a means for reducing the display size of the on-screen image (on-screen characters indicating the operating state of the television receiver, subtitles, etc.) is provided as it approaches the left and right end portions relative to the horizontal center of the display screen, A non-linear processing circuit enlarges the display size in the horizontal direction as it approaches the left and right edges relatively to the horizontal center of the display screen, so that an image with an aspect ratio of 4: 3 is displayed on the entire display screen with an aspect ratio of 16: 9. Even when displayed, the on-screen image is displayed in substantially the same size, and the on-screen image can be an undistorted on-screen image without distortion.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of an on-screen signal generator of the present invention.

FIG. 2 is a waveform diagram for explaining the operation of the on-screen signal generator of the present invention.

FIG. 3 is a diagram for explaining the operation of the on-screen signal generator of the present invention.

FIG. 4 is a diagram showing an on-screen image output from the on-screen signal generator of the present invention.

FIG. 5 is a block diagram showing an embodiment of a television receiver of the present invention.

FIG. 6 is a diagram for explaining the operation of the television receiver of the present invention.

FIG. 7 is a block diagram showing a television receiver of the present invention including a caption moving circuit.

8 is a block diagram showing a specific configuration of subtitle moving circuit 109 in FIG. 7. FIG.

FIG. 9 is a diagram for explaining the operation of the television receiver of the present invention including a subtitle moving circuit.

FIG. 10 is a diagram for explaining non-linear processing.

FIG. 11 is a block diagram showing an example of a conventional on-screen signal generator.

12 is a diagram showing an on-screen image written in VRAM 2 in FIG.

FIG. 13 is a diagram for explaining the operation of the conventional on-screen signal generator.

FIG. 14 is a diagram showing an on-screen image output from a conventional on-screen signal generator.

FIG. 15 is a block diagram showing an example of a conventional television receiver including a non-linear processing circuit and an on-screen signal generator.

FIG. 16 is a diagram for explaining the operation of the conventional television receiver.

[Explanation of symbols]

 1 character generator 2 VRAM 3,15 counter 4 shift register 5, 6, 18 reference signal generator 11 level comparator 12 A / D converter 13 field memory 14 D / A converter 16,61 parabolic waveform generation circuit 17, 62 VCO 101 Video chroma processing circuit 102 Synchronous separation circuit 103 Deflection circuit 104, 108 On-screen signal generator 105 Combining circuit 106 Non-linear processing circuit 107 CRT 108 Subtitle moving circuit

Claims (3)

[Claims] 1. A display screen having an aspect ratio of 16: 9, and in displaying a video having an aspect ratio of 4: 3 on the display screen, a display size in a horizontal direction is set relative to a horizontal center portion of the display screen. A non-linear processing circuit for displaying the image having the aspect ratio of 4: 3 on the entire display screen by enlarging the image as it approaches the left and right ends, and for superimposing an on-screen image different from the image on the display screen. In a television receiver including an on-screen signal generator, a means for reducing the display size of the on-screen image as it approaches the left and right end portions relative to the horizontal center of the display screen is provided. Characteristic television receiver. 2. An on-screen signal generator for generating an on-screen signal for superimposing an on-screen image different from an image displayed on a display screen on the image, the display size of the on-screen image being displayed on the display screen. An on-screen signal generation device, characterized in that means for reducing the size of the screen as it approaches the left and right ends relative to the horizontal center part is provided. 3. A display screen having an aspect ratio of 16: 9, and in displaying a video having an aspect ratio of 4: 3 on the display screen, a horizontal display size is set relative to a horizontal center portion of the display screen. A television provided with a non-linear processing circuit for displaying the video having the aspect ratio of 4: 3 on the entire display screen by enlarging the video as it approaches the left and right ends, and a caption moving circuit for extracting a caption component included in the video. In the John receiver, means for reducing the display size of the subtitle component extracted by the subtitle moving circuit as it approaches the left and right end portions relative to the horizontal center of the display screen is provided. John receiver.