JPS613587A - Character broadcast receiver - Google Patents

Abstract

PURPOSE:To obtain a character broadcast receiver from which a program number of a hybrid system character broadcast in recognized easily by detecting and storing the program number of a character broadcast transmitted at present and displaying it on a screen as a program list. CONSTITUTION:A CPU19 decodes a character signal written in a buffer memory 17 to check whether the character signal data is a page control data unit to come to the head of the program or not. If the data is the page control data unit, the program number is detected to check whether it is written in the program number list or not. When the number is a new number, it is added in the program number list. When a recipient selects the program number list, the receiver displays the program number list and when the channel is changed, the program number list formed so far is cleared and a new program number list is generated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a teletext receiver used for receiving hybrid teletext broadcasts in which no single set of screening information is transmitted.

[Prior art]

In hybrid teletext broadcasting, program selection information is not transmitted as in pattern teletext broadcasting. One side of the hybrid teletext is composed of several types of data units, including a page control data unit i at the beginning. FIG. 1 shows the configuration of the page control data unit.

As shown here, the page control data unit includes a check code 0ROf for detecting false errors (22 pies) (B
t to Bn). In the same figure,
SOH is a heading start code, US is a data unit division code, and a data unit identification code along with page control data unit 1-02/1? It consists of ETB is an end of transmission block code.

Note that DRO8 supports a character set (dynamically
Red6finable Character 5et
s) O? -.

Therefore, in hybrid teletext broadcasting, program search information is not transmitted, so the receiver cannot know the program number of the teletext broadcast that is currently being transmitted, which is inconvenient.

[Summary of the invention]

This invention was made to improve the above problem, and is configured to detect and store the program numbers of the hybrid teletext broadcasts currently being transmitted, and to display them on the screen as a list of all program numbers. The present invention proposes a teletext receiver that allows the receiver to know the program number of the hybrid teletext program currently being broadcast and makes it easy to select a teletext program.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to all the drawings.

FIG. 2 is an overall configuration diagram showing an example of a hybrid type teletext receiver according to the present invention. In the same figure, (
1) is a demodulation unit that receives television radio waves and extracts a video signal; (2) removes the character signal superimposed on the vertical blanking period of the video signal, decodes it, and outputs the video signal on the teletext screen. In the decoder section, which supplies red, green, and blue (hereinafter referred to as RGB) signals to a cathode ray tube (hereinafter referred to as CRT), which will be described later, there is a means (201) for separating and storing character signals from video signals, and decoding the character signals. And if it is a page control data unit that comes at the beginning of a program, what is its program number? : Means for outputting and storing (202), and means for adding the program number to the program number table to create a new program number table, and displaying the Homare group number table in response to the program selection key (g). 203), etc.

Is (3) the above RGB signal? This is a display unit that displays on a CRT. Note that (4) is a receiving antenna.

FIG. 3 is a block diagram showing a specific configuration of the device shown in FIG. 2. (6) is a tuner, and (6) is a video detection circuit, which constitute a demodulation section (1) that receives television radio waves and extracts a video detection signal. (7) is a video amplification and chroma demodulation circuit, (8) is a video switching circuit, and (9) is a CRT, and the display unit (3) is composed of the video switching circuit (8) and the CRT (9). .

αQ is a clamp circuit connected to the video detection circuit (6);
αη is a character signal separation slicer circuit that separates the character signal included in the vertical retrace period of the video signal using a slicer, the mouth is a synchronization separation circuit, α◆ is a sampling clock generation circuit for reading character signals, and 4 is a packet circuit, (6
) is a buffer memory write control circuit, αη is a buffer memory, Ql19 is a program selection key, (2) is a control circuit such as a central processing unit (hereinafter referred to as CPU), and (e) is a program ROM. Q is readout control circuit, (support)
stores the pattern and θ color memory. The above crty (
The program extracts the data of the program selected by the program selection key (to) from the character signal data in the buffer memory, processes the character signal according to the program ROMm, and writes it to the pattern and color memory (2). ing. (10-) is a color matrix circuit for display control which converts data in the pattern and color memory (2) into '1RGB signals, and the above-mentioned circuits (10-) constitute a character signal decoder section (2).

Next, the operation of the above structure will be explained with reference to FIG.

FIG. 4 is a flowchart showing a program for displaying a teletext program number table stored in the CPUQI program memory. .

First, after 0PUQ9 is initialized (processing step ■), the character signal written in the buffer memory αη is decoded (processing step (e)), and this character signal data is a page control data unit that comes at the beginning of the program. (judgment step (7)). If it is a page control data unit, the program number is detected in the processing step @),
Check whether this has already been written in the program number table (determination step @). If this program number is a new program number that has not yet been written in the program number table, "This new program number is added to the total program number table, and the program number table is rearranged in ascending numerical order." Step 12fl).Furthermore, if a program number already written in the program number list comes, it is ignored.This return completes the program number list of the hybrid teletext broadcast currently being transmitted. If the recipient selects the program number table using the program selection key (to) (decision step 00)
, the receiver displays the program number list (processing step c
1m) ). 9. If the channel μ is changed (judgment step (to)), the program number table created up to that point is cleared (processing step C11), and a new program number table is completely created. This allows recipients to know the arrival number of the teletext teletext currently being broadcast.

〔Effect of the invention〕

As described above, according to the present invention, the present invention is configured to detect and store the teletext program currently being transmitted in teletext broadcasts for which no program selection information is being transmitted, and to display this as a program number table. The receiver can easily know the teletext program currently being transmitted.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of a page control data unit for hybrid teletext broadcasting, FIG. 2 is an overall configuration diagram of a teletext receiver according to the present invention, and FIG. 3 is a specific configuration of the teletext receiver according to the present invention. FIG. 4 is a block diagram showing an example of the above, and is a flowchart for explaining the operation of the same teletext receiver. (1)...Character signal demodulation section, (2)...Character signal decoder section, (3)...Character signal display section, (g)...
Program selection key, (201)...Character signal separation storage means, (202)...Program number detection storage means, (203)
...Program number table creation means. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Claims] (1) In a teletext receiver that receives a character signal superimposed on the vertical blanking period of a television signal, decodes it, stores it in a display image memory, and displays it on the screen, program search information is obtained. When a character signal without a character signal is received, the program number of the currently transmitted teletext broadcast is detected and stored, and a program number table is created, which is displayed on the screen as a program number table when the receiver selects the number. What is claimed is: 1. A teletext receiver characterized in that a character signal decoder section is provided with a function for displaying images.