JPH02217085A - Television image receiver including teletext receiver - Google Patents

Abstract

PURPOSE:To make it possible to observe teletext by a slave screen or superimpose while observing a video screen independent of the teletext by separating a display clock from a teletext signal extracting clock. CONSTITUTION:An extracting part 16 extracts a teletext signal from a video signal clamped by a clamping circuit 10 based on a horizontal pulse 11 and a vertical pulse 12, S/P converts the extracted signal and transfers the converted signals to a display processing part 17 through a bus line 19. The display processing part 17 develops the character signal obtained from the extracting part 16 to image data for the slave screen by means of a horizontal pulse 23, a vertical pulse 24 and a display clock 15 in accordance with an instruction from a CPU 18 and outputs a character broadcasting RGB signal 20. An RGB switching part 22 switches a video RGB signal 21 and a teletext RGB signal 20 in accordance with a display procedure such as the position of the slave screen.

Description

[Detailed Description of the Invention] Industrial Field of Application The present invention makes it possible to view teletext on a sub-screen or superimposed while viewing video, video disc, or other signals on which no character signals are superimposed. This invention relates to a television receiver with a built-in teletext receiver.

2. Description of the Related Art A typical conventional television receiver with a built-in teletext receiver displays a teletext screen as a sub-screen within a main screen image. This has the advantage that you can watch teletext while watching the TV screen at the same time.

An example of a conventional television receiver with a built-in teletext receiver will be described below with reference to the drawings.

FIG. 2 shows a state in which two screens 31, a main screen and a child screen, are projected on the screen of a conventional television receiver with a built-in teletext receiver. , B is the sub-screen for teletext broadcasting, and B is the main screen for displaying a video screen such as a television.

FIG. 3 is a block diagram of a conventional television receiver with a built-in teletext receiver. In Fig. 2, 1 is an input switching unit that switches between a video signal from an external video or video disk and a television image signal, 2 is a video signal selected by input switching unit 1, and 3 is synchronized from video signal 2. 4 is a deflection processing section that performs horizontal and vertical deflection; 5 is a video signal processing section that reproduces images from video signal 2; 6 is a sub-screen/superimpose mode and full-page text. SYN to switch broadcast mode with control signal
7 is a video signal having a character signal selected by the SYNC switching unit 6; 8 is a display clock that is synchronized with the video signal 2 and generates a display clock signal that is the source of the system clock for display processing; generator, 9 is video signal 2
10 is a clamp circuit that clamps the video signal 2 with horizontal pulses; 11 is a horizontal pulse synchronized with the video signal 2;
12 is a vertical pulse 13 synchronized with the video signal 2 is a SYN composed of a synchronization signal based on a clock in the display processing section.
C: signal; 14 is a control signal for switching between sub-screen/superimpose mode and full-screen teletext mode;
15 is a display clock signal synchronized with the video signal 2 for displaying teletext; 16 is an extractor for extracting the teletext signal from the video signal; and 17 is according to the teletext protocol;
a display processing unit that develops character signals into image data, performs child screen mode and superimpose processing, and outputs RGB signals; 18 is a CPU that controls the teletext receiver; 1;
9 is a path line consisting of a communication bus control bus for teletext data, 2o is a teletext RGB signal of a teletext screen, 2
1 is a video RGB signal of the main screen, and 22 is an ROB switching unit that switches between a character screen and a video screen.

The operation of the television receiver with a built-in teletext receiver configured as described above will be described below.

5. Normally, when viewing a TV image signal or video input image only on the main screen, the input switching unit 1 selects an arbitrary signal, and the SYNC switching unit 6 selects the control signal 14 and the video signal 7. Switching is made so that video signal 2 is selected. Next, the synchronization signal is separated by the first synchronization separation section 3, and deflected by the deflection processing section 3. The video signal processing section 5 converts the video signal 7 into a video RGB signal 21, which is input to the RGB switching section. The R(,B switching section 22 always selects and outputs the video RGB signal 21.

Next is the case of watching teletext. As the first pattern,
When displaying a text broadcast on the main screen, the input switching section 1 must always select a television video signal, that is, a video signal having a text signal.

The SYNC switching section 6 is switched by a control signal 14 so as to select a synchronization signal (SYNC signal) 13 from a display processing section 17 as the video signal 7 . The first synchronization separation section 3 separates a synchronization signal from the SYNC signal 13, and the deflection processing section 4 performs deflection.

6/,> The second synchronization separator 9 separates the synchronization signal from the video signal 2, and outputs a horizontal pulse 11 and a vertical pulse 12 synchronized with each other. The extraction section 16 extracts the character signal from the video signal 2 clamped by the clamp circuit 10 using the horizontal pulse 11 and the vertical pulse 12, and passes it to the display processing section 17 through the pass line 19. The display processing section 17 outputs a teletext R (rB signal 20) from the horizontal pulse 11, the vertical pulse 12, and the character signal from the sampling section 16.

In this case, the teletext R(, B signal 20) is selected and output on the RGB switching section upper 2.

The second pattern is a case where a television image is displayed on the main screen B shown in FIG. 2, and a teletext is displayed on the small screen B. The input switching unit 1 is in a state where the teletext is viewed. The SYNC switching unit 6 is in the same state as when viewing a television screen or video screen, and the subsequent process up to displaying the image on the main screen is also the same.

Next is the teletext screen. A sampling section 16 extracts a character signal from the video signal 2 clamped by the clamp 7 Hoene circuit 10 using the horizontal pulse 11 and the vertical pulse 12, converts it from serial to parallel, and outputs it to the pass line 19.
The receiver is passed to the display processing section 17 through the display processing section 17. Display processing section 17
is the display clock signal 15 from the clock generator 8, and
The horizontal pulse 11, the vertical pulse 12, and the character signal from the sampling section 16 are developed into image data for a child screen according to instructions from the CPU 18, and a teletext RGB signal 2o is output.

RGB switching switching section Switches between the video input signal and the teletext RGB signal at any time depending on the position of the upper two sub-screens.

Problems to be Solved by the Invention However, in the above configuration, horizontal pulses and vertical pulses from the same synchronization separating section 9 are used as the display clock and the sampling clock for the display processing section 17 and the sampling section 16. Therefore, there was a problem in that the teletext broadcast could only be viewed when the input switching unit 6 selected a television video signal.

In view of the above-mentioned problems, the present invention provides a television receiver with a built-in teletext receiver that allows teletext broadcasts to be viewed on a small screen or superimposed while viewing a video screen unrelated to the teletext broadcasts.

Means for Solving the Problems In order to solve the above problems, the television receiver with built-in teletext receiver of the present invention separates the display clock and the clock for extracting the teletext signal and displays the main screen. Teletext broadcasts unrelated to television signals are displayed on a sub-screen or superimposed.

According to the television receiver with a built-in teletext receiver of the present invention, while watching a video input signal such as a video or a video disk unrelated to teletext broadcasting, you can watch the characters of any broadcasting station on a sub screen or superimposed. You can enjoy the broadcast.

Embodiment Hereinafter, a television receiver with a built-in teletext receiver according to an embodiment of the present invention will be explained with reference to the drawings.

FIG. 1 on page 9 is a block diagram of a television with a built-in teletext receiver according to an embodiment of the present invention.

In FIG. 1, 1 to 22 are the same as the conventional example shown in FIG. 23 is a horizontal pulse from the first synchronization separator 3;
Reference numeral 4 designates a vertical pulse from the first synchronization separator 3, 25 represents an external teletext input switching unit for selecting an arbitrary external teletext signal, and 26 represents a video signal selected by the external teletext input switching unit 25.

Both the horizontal pulse 23 and the vertical pulse 24 are synchronized with the horizontal drive pulse and the vertical drive pulse sent from the first synchronization separation section 3 to the deflection processing section 4, respectively.

The operation of the television receiver with a built-in teletext receiver configured as described above will be described below with reference to FIG.

First, when viewing TV images or video input signals only on the main screen, it is the same as the conventional example.

Omitted.

When viewing teletext on the main screen, the external teletext input switching section 26 selects a video signal containing an arbitrary character signal. From the selected video signal 26, the 210z, > sync signal is separated in the sync separator 9, and horizontal pulses 11,
The signal is inputted to the extractor 16 as a vertical pulse 12. The sampling unit 16 receives the video signal 26 clamped by the clamp circuit 1o using the horizontal pulse 11 and the vertical pulse 12.
A character signal is extracted from the character signal, converted into serial/parallel data, and passed through a pass line 19 to a display processing section 17 . The SYNC switching section 6 is controlled by the control signal 14.
Since SYNC signal 13 is selected for video signal 7,
The first synchronization separation section 3 separates a synchronization signal from the SYNC signal 13, and the deflection processing section 4 performs deflection. The display processing unit 17
The horizontal pulse 23 and vertical pulse 24 from the second synchronization separator 3 and the character data from the extractor 16 are developed into a teletext RGB signal.

Output. RGB switching section 2 As in the conventional example, the teletext RGB signal 2o is always selected and output.

Next, when outputting to the child screen, the input switching unit 1 selects an arbitrary video signal, and the external teletext input switching unit 25 is also in a state of selecting an arbitrary video signal. Extraction part 1
6 is horizontal pulse 11, vertical pulse 11A.

The teletext signal is extracted from the video signal 8 clamped by the clamp circuit 10 by the direct pulse 12, converted into serial/parallel, and passed to the display processing section 17 through the pass line 19. Further, the output horizontal pulse 23 of the synchronization separation section 3 is inputted to the clock generation section 8 as a reset signal, and the display clock of the clock generation section 8 is synchronized with the horizontal pulse 23. 15 is synchronized with the video signal 26, so that both video signals can be synchronized.

The SYNC switching unit 6 selects the video signal 2 as the video signal 7. The -th synchronization separation unit 3 separates a synchronization signal from the video signal 2, and the deflection processing unit 4 performs deflection. Display processing section 17
is the horizontal pulse 23, the vertical pulse 24, and the display clock 1.
5 to send the character signal from the extractor 16 to the CPU 1.
In accordance with the instructions in step 8, image data for the child screen is developed, and a teletext RGB signal 20 is output. The RGB switching section switches between the video input signal 21 and the teletext RGB signal depending on the display method such as the position of the upper two screens.

Effects of the Invention As described above, according to the present invention, it is possible to watch any teletext broadcast on the child screen while viewing video input signals unrelated to teletext broadcasts such as videos and video discs on the main screen. have

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a television receiver with a built-in teletext receiver according to an embodiment of the present invention, and FIG. 2 shows a main screen,
FIG. 3 is a block diagram of a conventional television receiver with a built-in teletext receiver. 1...Input switching section, 3...First synchronization separation section, 6...SYNC switching section, 8...Display clock generation section, 9...First synchronization separation section 2 synchronous separation section, 16...
...Extracting section, 17...Display processing section, 22
. . . RGB switching section, 25 . . . External teletext input switching section.

Claims (1)

[Claims] an input switching unit that selects a first video signal from a plurality of video signals; an external teletext signal switching unit that selects a second video signal from a plurality of video signals including a teletext signal; a clock generator that generates a display clock synchronized with a video signal; a first sync separator that separates a sync signal from the second video signal; and an output of the first sync separator from the second video signal. an extractor for extracting the teletext signal, a SYNC switching section for selectively outputting either the first video signal or the SYNC signal from the display processing section, and separating a synchronization signal from the output of the SYNC switching section. a second synchronization separation unit; a display processing unit that converts a character signal into a character RGB signal using a synchronization signal separated from a display clock and a SYNC signal; and a selection of one of the RGB signals of a text broadcast and a video signal. A television receiver with a built-in teletext receiver and an RGB switching unit.