JP2667599B2 - Television receiver with multi-screen display function - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0010]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a television receiver with a multi-screen display function, and more particularly to a multi-screen display function for preventing character information of a main screen from disappearing in a sub-screen in a multi-screen display state. The present invention relates to an attached television receiver.

[0020]

2. Description of the Related Art FIG. 3 shows a system block diagram of a conventional television receiver with a multi-screen display function. In FIG. 3, a main screen signal a is decoded by a decoder A into R, G, B signals and supplied to a switch SW. On the other hand, the sub-screen signal b is decoded into R, G, and B signals by the decoder B, and then the sub-screen processing circuit C thins out the scanning lines as appropriate and compresses the time axis to switch the switch SW in synchronization with the main screen. Supplied to

The switch SW appropriately switches between the main screen signal from the decoder A and the sub-screen signal from the sub-screen processing circuit C by a control signal generated by the controller D from the synchronizing signal of the main screen. The sub-screen 2 is displayed on the main screen 1 on the display section E as shown in FIG.

[0040]

In the television receiver with the multi-screen display function configured as described above, when character information such as emergency news displayed on the main screen at the time of multi-screen reception overlaps the sub-screen, the sub-screen is displayed. There was a problem that the part where it overlapped was erased.

An object of the present invention is to eliminate the above-mentioned problems, and an object of the present invention is to enable full-text display of character information displayed on a main screen while maintaining a multi-screen display state. It is.

[0060]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a television receiver with a multi-screen display function in which a child screen is displayed on a parent screen. First detecting means for detecting that the signal levels of G and B are substantially the same, second detecting means for detecting that the level of a luminance signal of the video signal is equal to or higher than a predetermined value, Character information detection means comprising third detection means for detecting that the outputs of the first and second detection means have continuity within a predetermined time at the same time; When the information is detected, it is detected that the display area of the character information overlaps the display area of the child screen to reduce the brightness of the child screen, and a brightness adjusting means for the child screen, and a display area of the character information of the parent screen. In the area where the display area of the Provided a superimposing means for displaying the character information of the parent screen in place of the image of the child screen is Te, also to the structure so as to be displayed on the child screen on the character information of the parent screen.

[0070]

[0080]

According to the above arrangement, when character information such as emergency news enters the main screen, the character information has substantially the same level of the R, G, and B signals, and the G signal has a higher level than usual. The outputs of the first and second detecting means are both at "H" level. These two outputs become signals having continuity within a predetermined time, and the third detector detects that the output is character information.

When the character information is detected, it is detected whether or not the display area of the character information overlaps the display area of the child screen. If the character information overlaps, the luminance of the child screen is reduced and the parent screen is displayed on the child screen. Superimposes text information on the screen. When it is detected that the character information of the main screen overlaps the display area of the child screen, the display position of the child screen is changed so that the character information does not overlap the child screen.

[0100]

FIG. 1 is a block diagram showing an embodiment of the present invention. In FIG. 1, a sub-screen video signal input from a sub-screen video input terminal 10 is supplied to a video decoder 11 for R, G,
After being decoded into a B signal, it is converted into a digital signal by the A / D converter 12, compressed into an appropriate size by the child screen signal processor 13, and at the same time, the changeover switch 14 is synchronized with the sync signal of the parent screen. Supplied to

The main screen video signal input from the main screen video input terminal 15 is supplied to the video decoder 16 and the A / D converter 17 in the same manner as in the case of the sub-screen video signal.
The signal is converted into a B digital signal and is supplied to the changeover switch 14 via the delay line 18. The R, G, B digital signals derived from the A / D converter 17 are the character detector 1
9 is also supplied, and character detection is performed here as follows.

FIG. 2 is a block diagram showing a detailed configuration of the character detector 19 shown in FIG.
The maximum value of the level difference between the G and B signal data is detected by a level difference detector 30, and the presence or absence of a color component is detected by a color component detector 31.

In general, telop characters such as emergency news do not include color components, so that the levels of the R, G, and B signals are substantially the same, and the output of the level difference detector 30 is reduced. That is, when the output of the level difference detector 30 is small, there is no color component, so this is used as character information, and the color component detector 31 outputs an "H" level detection signal.

At the same time, the level detector 32 detects the level of the G signal. Since the character information such as the telop character has a high brightness level, the G signal level becomes high. Therefore, when the level of the G signal exceeds a certain threshold value, the level detector 32 outputs an "H" level detection signal as character information. The detection signal thus obtained is AND
The signal is guided to a circuit 33, an AND output is taken, and then supplied to a character characteristic detector 34 for detecting the characteristic of the character.

The character characteristic detector 34 detects whether or not it is character information based on the character size characteristic. In the case of character information, the output of the AND circuit 33 is, for example, 100 n
Only in the range of s to 2 μs is the “H” level continuously. Here, using the characteristics of this character information,
The case where the "H" level output from the ND circuit 33 occurs within the above-mentioned certain period of time is detected, it is judged to be character information, and it is output as character period data.

The detection result determined by the character detector 19 as described above is supplied to the controller 20.
Based on the synchronization signal of the main screen and the character information determination result, the controller 20 selects a main screen signal in the main screen display section and a sub screen signal in the sub screen display section in a normal state where character information is not detected. Control 14 to display the child screen on the parent screen.

If the character information data is also detected in the display area of the child screen, the parent screen is also selected in dot units in the child screen display unit in accordance with the detection result, and the character of the parent screen generated in the display area of the child screen is selected. The information is superimposed on the small screen and a control signal is sent to the small screen decoder 11 so as to reduce the luminance of the small screen in units of several fields, so that the superimposed character information on the small screen can be easily viewed.

[0180]

The video signal in which the loss of character information has been prevented as described above is converted into an analog signal by the D / A converter 21 and then supplied to the display 22 for multi-screen display.

[0200]

Since the present invention has the above-described configuration,
Even in the multi-screen display operation, the full text can be displayed without missing the telop characters such as emergency news appearing on the main screen on the sub screen.

[Brief description of the drawings]

FIG. 1 is a block diagram of one embodiment of the present invention.

FIG. 2 is a block diagram of a main part of the present invention.

FIG. 3 is a block diagram of a conventional example.

FIG. 4 is an explanatory diagram of a display screen during multi-screen display.

[Explanation of symbols]

 14 Changeover switch 19 Character detector 20 Controller 30 Level difference detector 32 Level detector 33 AND circuit 34 Character characteristic detector

Claims (1)

(57) [Claims] 1. A television receiver with a multi-screen display function in which a child screen is displayed on a parent screen, it is detected that the signal levels of video signals R, G, B of the parent screen are substantially the same. First detection means, second detection means for detecting that the level of the luminance signal in the video signal is equal to or higher than a predetermined value, and outputs of the first and second detection means simultaneously for a predetermined time. Character information detection means comprising third detection means for detecting continuity within the sub-screen; and when the character information detection means detects character information of the main screen, the display area of the character information is displayed on the child screen. Of the sub-screen brightness adjusting means for detecting the overlap of the sub-screen display area to reduce the brightness of the sub-screen, and in the area where the text information display area of the main screen and the sub-screen display area overlap each other, The character information of the main screen is displayed instead of Super and superimposing means, the provided multi-screen display function with a television receiver, characterized in that it was set to also be displayed on the child screen character information of the parent screen to be.