KR920009876B1 - Pip (picture in picture) device of teletext - Google Patents

Abstract

In teletext screen picture-in-picture (PIP) apparatus for improving the reliability of products, the image signal selected by tuner (1), the signal detected by image detector (2) and the outputted signal of teletext moduler (4) are converted into the luminance and the chrominance signal by using the color encoder (5), followed by reducing the signal to 1/2 size through the sampling section (7) controlled by PIP controller (5). The reduced signal is converted into the digital signal by using the A/D convertor (8), and then stored at memory (9). The digital signal is converted into the analog signal by D/A convertor (10), followed by displaying the analog signal on screen of CRT through the chroma treatment sect. (12).

Description

Teletext PIP Devices on TV Receivers

1 is a block diagram of an apparatus of the present invention.

2a and b are dot comparison diagrams of the mother screen.

3A and 3B are timing diagrams of a sampling control signal.

4 is a configuration of a pip screen according to the present invention.

5 is a circuit diagram of a teletext screen-pep apparatus in a conventional TV receiver.

* Explanation of symbols for the main parts of the drawings

1: tuner 2: image inspection unit

3: tuning control unit 4: teletext modular

5: color encoder 6: pipe controller

7: Sampling unit 8: A / D converter

9: memory 10: D / A converter

11: Y, C switching unit 12: Chroma processing unit

13: Braun tube 14: horizontal and vertical drive unit

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a teletext screen pipe device in a television receiver. In particular, a teletext screen of a NABTS (including a domestic method) can be piped without damage to information and a teletext screen can be formed with a TV broadcast signal. The present invention relates to a teletext screen-pep device in a TV receiver that enables viewing and simultaneously displaying text information of several pages on one screen.

In the conventional TV receiver, the teletext screen-pep apparatus comprises: a tuner 33 for tuning the TV broadcast signal received by the antenna 32 by the output signal of the tuning control unit 31, as shown in FIG. The image detector 34 detects an image signal in the broadcast signal tuned by the tuner 33, and outputs color signals R, G, and B by receiving the image signal output from the image detector 34. A color encoder 36 which receives a teletec sheet modular 35, a color signal RGB output from the teletellest modular 35, and outputs a predetermined video signal, and the image detector 34 A mother screen and a child screen selecting unit 37 for receiving a video signal output from the color encoder 36 and outputting predetermined data to the mother screen and the mother screen by the control signal output from the pipe controller 38; The chroma processing units 39 and 40 for separating the signals output from the mother screen and the sub-screen selection unit 37 into the color difference signals RY, BY, GY and the luminance signal Y, respectively, and the teletext screens are piped. In order to output a predetermined control signal to the pipe controller 38 and the pipe controller 38 The sampling unit 41 converts the output signal of the chroma processing unit 40 in series by the control signal outputted from the control unit, and the A / D converter 42 converts the analog signal input from the sampling unit 41 into a digital signal. ), A memory 43 which is controlled by the pipe controller 38 to store output data of the A / D converter 2, and a D / A which changes data stored in the memory 43 into an analog signal. The output of the chroma processor 39 controlled by the converter 44, the GY demodulator 45 for demodulating the color difference signal GY among the output signals of the D / A converter 44, and the pipe controller 38; RGB signal switching unit 46 for selectively switching the output of the GY demodulator 45 and the mother screen image signal output from the mother screen and the sub-screen selection unit 37 receives the horizontal and vertical of the CRT 47 By interconnecting the horizontal and vertical drive unit 48 for driving the deflection unit His working relationship is as follows.

First, an existing TV pipe modulator is used to pipe the teletext screen, and the output signal RGB of the teletext modular 35 is inputted to the mother screen and the selector 37 to input the image signal once. The coder 36 converts the image into a composite video signal.

In addition, the mother screen signal selected by the mother screen and the mother screen selection unit 37 controlled by the pipe controller 38 is converted into the color difference signals RY, BY, GY and the luminance signal Y by the chroma processing unit 40. In order to save the capacity of the memory 43 and maximize the PIP screen, only the RY, BY signal and the luminance signal Y of the color difference signals are inputted to the sampling unit 41 to control the PEP controller 38. The sample is sampled as serial data and output to the A / D converter 42.

Therefore, the A / D converter 42 separates the sampled signals into RY, BY, and Y signals, respectively, and digitizes them, and stores them in the memory 43. The memory 43 is controlled by the pipe controller 38. In accordance with the horizontal and vertical synchronization of the mother screen, the data of the RY, BY, and Y signals are output to the D / A converter 44, respectively, according to the command of the tuning control unit 31.

In addition, since the D / A converter 44 converts the signal into an analog signal and inputs it to the GY demodulator 45, the GY demodulator 45 demodulates the color difference signal GY and then the RGB signal switching unit 46. Since the input operation is performed, the switching operation is performed in the RGB signal switching unit 46 to be piped. However, such a conventional device has one-third reduction in the horizontal direction and one-third reduction in the vertical direction in order to pipe an analog screen. There is no problem, but in the case of the child screen, the dots constituting the character have a problem in that the character cannot be read during the reduction process.

The present invention has been proposed to solve such a conventional problem, and the luminance and color signals (Y, C) of the color encoder are input to the sampling unit for processing the subtext of the pipe without losing the teletext signal. Two control signals are input to the sampling unit, and the pipe controller receives the data clock signal from the tuning controller, and the output of the memory converts the luminance and color signals through the D / A converter to convert the image detector and the chroma. By inputting to the luminance and color signal leveling unit connected between the processing unit, the information on the teletext screen is piped without damage and appears with the broadcast signal on the TV receiver, and simultaneously displays 4 pages of teletext information on one screen. It is an object of the present invention to provide a teletext screen-pep device in a TV receiver which can be used. When referring to the drawings budoen the present invention is described in detail as follows.

As shown in FIG. 1, the apparatus of the present invention is characterized in that the video signal tuned by the tuner 1 is controlled by the tuning control unit 3 and the signal detected by the image detection unit 2; The output signal is converted into luminance and color signals (Y, C) for the color encoder (5), and then reduced to 1/2 via a sampling unit (7) controlled by the pipe controller (6) and an A / D converter A signal converted into a digital signal through the memory 10 and stored in the memory 9 and then converted into an analog luminance and color signal Y and C through the D / A converter 10 is output to the output of the pipe controller 6. It is selected by the Y, C switching unit 11 to be displayed on the image surface of the CRT 13 through the chroma processing unit 12, wherein reference numeral 14 is a horizontal and vertical driving unit. Referring to Figures 2 to 4 the effect of the device of the present invention configured as described above is as follows.

First, there should be no damage to the basic dots constituting the characters so as not to damage the information when the teletec sheet screen is screened by PPRO. That is, as shown in Figs. 2A and 2B, one TV screen (one frame) during interlaced scanning of a TV broadcast consists of two field scans of the radix field and the even field, and thus the basic dots (1 dot; Since the basic pixel as a set of pixels consists of 0.17μs in the horizontal direction and two main lines in the vertical direction, it is basically impossible to reduce the vertical direction by more than 1/2 to prevent the dots from being damaged when the screen is reduced. In addition, 1/2 reduction is most preferable for the formation of basic dots in the horizontal direction. That is, in the present invention, if the existing pip method takes one line from three horizontal servants in one-third reduction-1 field as sampling and discards the other two lines, video information of the taken line is displayed on the pip screen. Select one line out of two horizontal lines and output it.

Therefore, although the amount of information is increased than the conventional method, the information is displayed on the screen at 256 × 200 dots (TXT standard) in the case of teletesheet information. One pixel (= 1 dots) is used in the radix field and the even field as described above. In the case of 1/3 reduction, the information is completely lost. However, if 1/2 reduction is performed by sampling only once in the radix field or the even field, the fear of information loss can be solved.

Therefore, in the apparatus of the present invention, the RGB image signal of the teletext module 4 is synthesized through the color encoder 5 into the luminance and color signals (Y, C) for half reduction in the horizontal direction, and then the pipe controller 6 By the sampling control signal (the phase is 180 degrees out of phase) accumulated in the step 2), the sampling unit 7 is reduced to 1/2, and this control signal is sampled only once in two scan lines for the reduction in the vertical direction.

That is, as shown in a and b of FIG. 3, the sampling control signals Ys and Cs of the luminance signal Y and the color signal C are 180 degrees out of phase with each other, thereby sampling at an active low (or active high) timing. In this case, the sampling of the luminance signal Y is preceded and the sampling of the color signal C is performed at the next timing. Therefore, the luminance signal Y is sampled in the section A, and the color signal C is sampled in the section B. Is done.

That is, in the case of the reduction of the vertical line, since 1 dot is composed of two main lines as described above, the pip controller 6 is only sampled once in the radix field (or even field), so it is reduced by 1/2 and the sampling control signal is reduced. As a result, one sampling per two scan lines is performed.

In addition, the sampled analog signal is converted into a digital signal through the A / D converter 8 and stored in the memory 9 controlled by the pipe controller 6, where the pipe controller 6 is adapted to the user's request. Accordingly, the teletext screen of one screen or four screens is decoded from the memory 9 by an instruction instructed by the microcomputer in the tuning control section 3, and outputted in synchronization with the main screen.

That is, as shown in the screen configuration of FIG. 4, the teletext information (pip screen) reduced by 1/2 horizontally and vertically produces a pip screen with a 1/4 size of the whole screen on the screen and displays the four screen information. By the viewer's choice, one or two or four can be viewed simultaneously.

On the other hand, the digital signal stored in the memory 9 and output by the pipe controller 6 is reproduced as analog luminance and color signals (Y, C) through the D / A converter 10, and then Y, C switching. As input to the unit 11, the Y, C switching unit 11 is controlled by the pipe controller 6 to be switched and controlled together with the luminance and color signals Y and C in the TV broadcast signal and then to the chroma processing unit 12. Since it is input to the CRT 13, the teletext screen appearing on the CRT 13 screen can be piped without damage.

As described above, according to the present invention, the teletest screen can be piped without damage to information and displayed on one screen together with the TV broadcast signal. In particular, four pages of teletext information can be displayed on one screen. Simultaneous display can further improve product reliability.

Claims (1)

The video signal tuned by the tuner 1 is detected by the image detector 2 and the output signal of the teletext regulator 4 controlled by the tuning controller 3 is the color encoder 5. Is converted into luminance and color signals (Y, C) by the microcontroller, and is reduced to 1/2 through the sampling unit (7) controlled by the pipe controller (5), and converted into a digital signal through the A / D converter (8). The signals stored in (9) and then converted into analog luminance and color signals (Y, C) through the D / A converter 10 are outputted by the Y, C switching unit 11 by the output of the pipe controller 6. A teletext screen pipe (pip) device in a television set, characterized in that selected and configured to appear on the screen of the CRT (13) through the chroma processing unit (12).

Images