JP2003219320A - Video display apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce baking of a video display apparatus in the case that a black stripe part for aspect conversion exists in video contents. <P>SOLUTION: A black level detection means 2 detects whether or not a black stripe part exists in upper/lower/left/right positions of an input video signal 1 and the start and end positions of the black stripe part, a timing generating circuit 5 generates a switching signal in matching with the black stripe part detected by the black level detection means 2, and a signal changeover switch 6 replaces the black stripe part of the input video signal 1 with the signal from a mask signal level generator 4 and outputs the replaced signal. Thus, the black stripe part in the video signal is brought into a gray color so as to reduce baking. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to 16: 9, 4 :.
3. A video display device capable of displaying video with other aspect ratios, and a video capable of receiving broadcasts having a signal standard of both 16: 9 and 4: 3 aspect video signals such as BS digital broadcast receivers The present invention relates to a display device.

[0002]

2. Description of the Related Art Conventionally, when a video signal having a screen aspect ratio different from that of the video image is displayed on a video display device, in order to prevent uneven burn-in on the display surface of the video display device, it is not possible to simply blank the blank area without the video. As a method of illuminating the screen in some form without the above, the method described in Japanese Patent Application Laid-Open No. 2001-175212 is known.

In this conventional display burn-in prevention device, when the aspect ratio of an input video signal and the aspect ratio of a video display device used for display are different, gradation is gradually applied to an extra area of the screen due to aspect conversion. By adding a signal with a mark, it is possible to prevent image sticking from occurring in the screen.

[0004]

However, although the above-mentioned configuration is a countermeasure against burn-in of a surplus portion of the screen generated during the aspect conversion processing performed by the video display apparatus itself, the video signal contains For example, some scope-size movie software has a part that is always black in the video signal. Of course, even with such video software, uneven image sticking may occur, but there is a problem in that it is not possible to take measures against such an image signal.

The present invention has been made in view of the above problems, and an object thereof is to reduce uneven image sticking.

[0006]

In order to solve this problem, the video display device of the present invention has a black remaining in a video signal existing in a video source in which the aspect ratio of the video standard and the aspect ratio of the actual video are different. A mask adding means for displaying a screen by adding a gray mask to the portion is provided.

According to the present invention, even when an image having an aspect ratio different from that of a video display device and having black bands at the top, bottom, left or right of the screen is displayed, an effect of preventing local image sticking of the video display device can be obtained. it can.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION That is, the invention according to claim 1 of the present invention is characterized in that a black extra portion in a video signal existing in a video source in which the aspect ratio of the video standard and the aspect ratio of the actual video are different, It is characterized by having a mask adding means for displaying a screen by adding a gray mask.

According to the second aspect of the present invention, there is provided black detection means for detecting the presence of a black portion above and below the image or to the left and right of the image within the image signal and for detecting the width of the black portion, and A mask adding means for replacing a black portion obtained from the black detecting means in the video signal with a signal having a constant voltage higher than the pedestal.

Further, according to the invention of claim 3, the aspect ratio of the display device is 16: 9, and the video standard is 16: 9, but the actual video content is 4: 3, and the left and right sides of the screen. 4: 3 meaning to allow rounding down and displaying
A video display device capable of receiving a broadcast having a display control signal as a broadcast standard, the display device being provided with a control signal detecting means for detecting the 4: 3 display control signal and the 4: 3 display control signal. And a mask adding means for displaying a gray mask by adding it to the left and right edges of the screen.

According to the present invention as described above, even when a black portion already exists in the signal of the image software such as the scope size image software, the black portion is replaced with a signal level that does not easily burn in. Thus, the image display device has an effect of preventing image sticking. Further, the aspect ratio of the display device is 16: 9, and the video standard is 16: 9.
However, in the case of a video display device capable of receiving a broadcast having a 4: 3 display control signal in a broadcast standard, which means that the actual video content is 4: 3 and the left and right sides of the screen are truncated and displayed, In addition, it has the effect of reducing uneven burn-in in areas not used in the image.

A video display device according to an embodiment of the present invention will be described below with reference to the drawings of FIGS.

(Embodiment 1) FIG. 1 is a block diagram showing a main configuration of an image display apparatus according to Embodiment 1 of the present invention. In FIG. 1, 1 is an input image signal input to the image display apparatus. Reference numeral 2 denotes a black detecting means to which the input video signal 1 is input. It detects the presence or absence of a black band and its start and end points. It detects the presence of a black part at the top and bottom of the image or at the left and right of the image, and also detects the width of the black part. .

Reference numeral 3 denotes a mask adding means for adding a gray screen mask to a black portion of the input video signal 1 which is black in the input video signal 1. The black part obtained from No. 2 is replaced with a signal in which a certain voltage is raised from the pedestal. Further, the mask adding means 3 includes a mask signal level generator 4 for generating a video signal of a mask portion to be added to the top, bottom, left and right of the image, and whether the black portion detected by the black detecting means 2 is up, down, left or right. Separately, based on the information of the start and end points of the black portion, a timing generation circuit 5 for generating a timing signal for replacing the black portion of the image with a mask signal, and a control signal of the timing generation circuit 5 for controlling the input. It is composed of a video signal 1 and a signal changeover switch 6 for switching the signals of the mask signal level generator 4.

Reference numeral 7 is a microcomputer for controlling the mask signal level generator 4 and the timing generating circuit 5 based on the detection result from the black detecting means 2, and 8 is an output video signal output from the mask adding means 3. .

Next, the operation of the video display device having this configuration will be described. For example, when the input video signal 1 is a video with black bands 21 at the top and bottom as shown in FIG. 2A, the black detection means 2 detects that there are black portions at the top and bottom, and at the same time, in the video. The start position and end position of the black portion are detected. The above information detected by the black detecting means 2 is read by the microcomputer 7 to cause the mask signal level generator 4 to generate a voltage corresponding to a gray image, and the timing generating circuit 5
Is set so that a mask switching timing pulse matching the black portion detected by the black detecting means 2 is generated.
The signal changeover switch 6 switches the signal between the input video signal 1 and the mask signal level generator 4 by the timing generation circuit 5.

According to such a configuration, as the output video signal 8, the black band 21 portion of the original video is gray 2 as shown in FIG.
The image replaced with 2 can be obtained, and uneven image sticking can be reduced.

2A and 2B show the case where there are black portions at the top and bottom of the image, but when there are black portions at the left and right of the image, they are shown in FIGS. 3A and 3B, respectively. It becomes the operation shown.

(Embodiment 2) FIG. 4 is a block diagram showing a main configuration of an image display apparatus according to Embodiment 2 of the present invention. In FIG. 4, the display device has an aspect ratio of 16:
9 and the video standard is 16: 9,
What is explained as a realization means added to a broadcast receiver capable of receiving a broadcast having a 4: 3 display control signal in a broadcast standard, which means that the left and right sides of the screen are truncated and displayed when the actual video content is 4: 3. Is.

In FIG. 4, 11 is a bit stream signal which is digital data such as video / data sent by broadcasting, 12 is a bit stream signal 11 which is received,
Video aspect information decoding means for extracting the video aspect information transmitted by the broadcasting station, and control signal detecting means for detecting the 4: 3 display control signal. Input video signal 1,
The mask adding means 3, the mask signal level generator 4, the timing generation circuit 5, the signal changeover switch 6, the microcomputer 7, and the output video signal 8 have the same functions as those described in the first embodiment, and therefore their explanations are omitted. To do.

Next, the operation of the video display device as a broadcast receiver with this configuration will be described. Taking the case of BS digital broadcasting as an example, in the case of 1080i, 16: 9 aspect ratio broadcasting and converting and displaying this content on a 4: 3 receiver, black bands are added above and below the video. In addition to the method of displaying the entire original image in the center of the screen with an aspect ratio of 4: 3, a conversion method is also possible that deletes the left and right edges of the original 16: 9 aspect ratio image to create a screen with an aspect ratio of 4: 3. Is. Whether the latter conversion method is possible depends on BS
According to the digital broadcasting standard, it is possible to inform the broadcasting station of the latter conversion method by a data string. This conversion method originally has an aspect ratio of 4: 3.
Aspect ratio of 16:
When the data is transmitted at 9, the left and right ends are meaningless information and are used when there is no problem in deleting and displaying.

This means that, in the case where the latter conversion is possible in the data string from the broadcasting station, the left and right ends of the aspect ratio of 16: 9 are often meaningless black. It is possible to make a determination, and by detecting this state and replacing the left and right edges of the image with gray image signals, it is possible to prevent burn-in of the image display device.

The video aspect information decoding means 12 comprises:
It is detected from the bit stream signal 11 whether the broadcast has an aspect ratio of 16: 9 and is permitted to be converted to 4: 3 by deleting the left and right ends. This information is transmitted to the microcomputer 7, and in the case of broadcasting in which 4: 3 conversion is possible by deleting the left and right ends, the microcomputer 7 causes the mask signal level generator 4 to generate a voltage corresponding to a gray image, and the timing generation circuit 5 Is set to generate a timing pulse that replaces the video signal with the mask signal in a portion other than the 4: 3 portion in the center of the screen. The signal changeover switch 6 switches the signal between the input video signal 1 and the mask signal level generator 4 by the timing generation circuit 5. That is, the mask adding means 3 performs an operation of adding a gray mask to the left and right edges of the display screen to display when a 4: 3 display control signal is present.

According to this structure, as the output video signal 8, an image in which the black portions on the left and right of the original image are replaced with gray can be obtained as shown in FIG. 3B, and uneven image sticking is reduced. Can be made.

In the second embodiment, the function is built into the broadcast receiver and explained as the invention of the broadcast receiver. However, the signal obtained by the video aspect information decoding means in the broadcast receiver is connected to the video display device, It can be similarly implemented in a mode in which the image adding device has the mask adding means.

[0026]

As described above, according to the present invention, an error that may occur when a video signal in which a part which is always black is already present in the video signal such as scope size movie software is displayed. The effect that uniform image sticking can be reduced is obtained.

[Brief description of drawings]

FIG. 1 is a block diagram showing a video display device according to a first embodiment of the present invention.

2A and 2B are explanatory diagrams showing video examples of an input video signal and an output video signal in the present invention.

3A and 3B are explanatory diagrams showing video examples of an input video signal and an output video signal in the present invention.

FIG. 4 is a block diagram showing a video display device according to a second embodiment of the present invention.

[Explanation of symbols]

1 Input video signal 2 Black detection means 3 Mask addition means 4 Mask signal level generator 5 Timing generation circuit 6 signal changeover switch 7 microcomputer 11 bit stream signal 12 Video aspect information decoding means

Claims (3)

[Claims] 1. A mask adding means for displaying a screen by adding a gray mask to a black remaining portion in a video signal existing in a video source in which a video source has an aspect ratio different from that of the video standard. Video display device characterized by. 2. A black detecting means for detecting the presence of a black portion above and below or to the left and right of the image in the video signal and for detecting the width of the black portion, and the black detecting means in the input video signal. And a mask adding means for replacing the black portion obtained from the above with a signal having a certain voltage higher than that of the pedestal. 3. The aspect ratio of the display device is 16: 9, and the video standard is 16: 9, but the actual video content is 4: 3, which means that the left and right sides of the screen can be truncated and displayed. Of the video display device capable of receiving a broadcast having a 4: 3 display control signal as a broadcast standard, the control signal detecting means detecting the 4: 3 display control signal, and the 4: 3 display control signal. In this case, the image display device is provided with a mask adding means for displaying a gray mask by adding it to the left and right edges of the screen of the display device.