JPS62190987A - Teletext receiver - Google Patents

Abstract

PURPOSE:To prevent an image plane where data has an error from being displayed by comparing the counted values of error character signal packets of two current and last received programs which are stored in a memory means by a control means, and reading out and displaying received data corresponding to a smaller counted value. CONSTITUTION:An error correcting circuit 5 detects an overlap H from a vertical and a horizontal synchronizing signal, input binarization data and corrects its error, and stores the error correction result of packet data in a buffer memory 6. When an interruption is initiated to complete the error correction, a CPU 7 reads the data out of the buffer memory 6. When the reading operation is carried on up to the last packet of a desired program, the packet error rate of data which are received last and the packet error rate of data which are received this time are calculated respectively. Then, the last and current packet error rates are compared with each other and when the current rate is smaller than the last error rate, program data which are received this time are displayed as an image plane.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a teletext receiving device, and in particular to a method for receiving character signal packets superimposed within the vertical blanking + 111 interval of a video signal transmitted from a broadcasting station. This is a teletext receiving device that displays received data (programs) consisting of a plurality of character signal packets and repeatedly transmitted in sequence, so that more correct information can be obtained by displaying the data with fewer errors. The present invention relates to a teletext receiving device.

(Prior technology) Recently, a new broadcasting service has been teletext broadcasting (hereinafter referred to as
teletext) has been put into practical use.

Furthermore, compared to the conventional pattern method, there is a hybrid method that combines the advantages of the pattern method with a code method for transmission speed.

Unlike regular television programs that are organized by time, teletext repeatedly transmits a variety of information and entertainment programs consisting of text, graphics, and additional sounds. This is a new broadcasting system that allows the ministry to use the information it wants, when it wants it.

Information such as the above text image is multiplexed with the television radio waves (video signals) from the broadcasting station currently being broadcast, and the receiver side is equipped with a receiving device V or adapter that can receive text broadcasting. If you prepare a teletext program, you can select and enjoy a desired teletext program from among many teletext programs.

In addition, this teletext signal (text signal packet) is the current television video signal RF! The signal is transmitted as a digital signal using a single interval (i.e., vertical blanking period), and the receiving device decodes the signal, converts it into a television signal, and displays the image on the television screen. It is now possible to watch text programs with additions and music, etc.

Furthermore, the above character signal packet is
A program consists of one page or multiple pages. Also, one number II (specific program) is about 20
It is repeatedly transmitted from the broadcasting station at intervals of ~30 seconds.

(Problems to be Solved by the Invention) By the way, character signal packets may include errors added to the received data due to interference on the transmission path, and errors that cannot be corrected. Yes, it may be displayed as an incomprehensible pattern (shape), or
Displayed as incorrect characters on the screen. ' Also, as mentioned above, each time the receiving device receives data (character signals) that are repeatedly sent out from a broadcasting station at intervals of about 20 to 30 seconds, it sequentially receives the latest data based on the latest data. The program screen is displayed.

However, if there is an error in the newly sent data (character signal packet), it is better to display the data about 20 to 30 seconds before that data, for example, than to display it as is based on the incorrect data. This program was sent out to
In some cases, it may be possible to display a more accurate program screen by redisplaying the program based on data with fewer errors.

However, as mentioned above, each time the receiving device receives data (text signal packets) repeatedly sent from a broadcasting station, it sequentially displays the latest program screen based on the JfflFt data. Although this is a new transmission order, it has the problem of displaying a screen with errors in data (character signal packets).

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a teletext receiving apparatus that solves the problems of the conventional techniques described above.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a teletext program device δ that receives a character signal packet superimposed within the vertical blanking interval 11 of a television signal. an error detection means for detecting errors in the character signal packet; and a numerical means for calculating the number of erroneous character signal packets detected by the error detection means for each received program composed of a plurality of character signal packets; a memory means for sequentially storing the number of error character signal packets for each received program counted by the counting means; a count value of the error character signal packets of the latest received program stored in the memory means; A control means is provided for controlling the received data to read out and display the received data having the smaller open value by comparing the count value of the error character signal packet of the received data related to the first received data previously stored in the memory. The present invention provides a teletext receiving device characterized by the following.

(Function) In the teletext receiver having the above configuration, the count value of the erroneous character signal packets of the latest one received program stored in the memory means and at least the one reception data stored before that are stored. The received data is compared with the counted value of the error character signal packet, and the received data with the smaller counted value is read out and displayed.

(Embodiment) An embodiment of the character f+ transmitting/receiving device according to the present invention will be described below with reference to the drawings.

FIG. 1 is a block system diagram showing an embodiment of a teletext receiving apparatus according to the present invention.

In the figure, 1 is an input terminal to which a video signal is supplied;
A character signal is superimposed on one or more H's within the vertical blanking period of this video signal.

Input terminal 1 is connected to binarization circuit 2. It is connected to an error correction circuit 5 via a clock regeneration circuit 3 and a synchronization detection circuit 4, respectively, and the error correction circuit 5 detects errors in digital data constituting a character signal and corrects the errors.

6 is a buffer memory for storing (memory) the error correction result of the data corrected by the error correction circuit 5, and 7 is a microcomputer (CPU).

Reference numeral 8 denotes a desired program number acquisition unit, which receives an input transmission data signal transmitted from the remote control transmission 1119 for selecting (receiving) a desired program by the receiver by key operation of a remote control button, and transmits the received data to the CPU 7. It is intended to supply

10 and 11 are work memory (RAM) and program memory for operating CPtJ7, respectively;
2c Image display memo') (VRAM: Video.

13 is an image display device such as a television receiver.

Next, the operation of the teletext receiving apparatus of the present invention having the above configuration will be explained.

In FIG. 1, the video signal input to input terminal 1 is
It is binarized by the binarization circuit 2, and the clock regeneration circuit 3
The sampling clock generated (regenerated) by the synchronization detection circuit 4, the vertical synchronization signal and the horizontal synchronization signal detected by the synchronization detection circuit 4 are respectively supplied to the error correction circuit 5.

The error correction circuit 5 detects the superimposed H using the vertical synchronization signal and the horizontal synchronization signal, takes in the binarized data using the sampling clock, performs error correction, and performs error correction on each of the data (
The error correction results of the packet data of the encoded transmission method superimposed on the data are stored in the buffer memory 6 (memory).

Here, the operation of the CPU 7 will be explained with reference to the flowchart shown in FIG.

First, CPtJ7 determines whether error correction is completed [step 21]. This is determined when the error correction performed from the error correction circuit 5 at the period of the vertical synchronization signal (field period) is completed and the CPU 7 receives an error correction completion signal by an interrupt. When an interrupt occurs and the error correction is completed, the CPU 7 selects the data stored in the buffer memory 6 (error correction result data).
It is checked whether the data is a character signal of the encoded transmission method by reading out the data and checking the presence or absence of Sl (service identification) in the bit near the beginning of each data.

If the data is a character signal of a coded transmission method, the type of the packet is further checked to see if it is a program data header (PAC[)] [Step 22]
, if it is a program data header [yes], the program number is extracted from the program data header [step 23].

Also, in step 22, if the program data header is
-J [no], page data header (PIICI)
If it is a page data header, [ycs] is checked, and the program number is extracted from the page data header [step 25].

Next, check the program number extracted in steps 23 and 25 and the program number desired by the recipient imported from the desired program number importing section 8 [step 26], and if they match [
yes], first, the number of error packets received this time (
In other words, the number of error packets among the packets that make up the most recently received program) and the total number of packets of currently received data (the total number of packets that make up the most recently received program)
are set to O (pyro) respectively [Step 27]. In other words, the packet number memory (counter) of the work memory 10
Clear the data (counter l1lli).

First, one received packet data is stored (memory) in the currently received data memory [step 28
].

Here, as shown in FIG. 3, the memory for received data (work memory 10 in FIG. 1) is [memory for currently received program data], and the memory for received data previously (approximately 20 to 30 seconds ago) related to this program. There is a ``previously received program data memory'' for the data memory of the program that was received, and ``previously received data total number packet number memory (counter) J, r#i times received data total error device but 1 to several memories It consists of ``memory for the total number of buckets of currently received data (counter)'', ``memory for the total number of packets for currently received data (counter)'', and ``other memories''.

Furthermore, the memory a for previously received program data in FIG.
As shown in FIG. 4, the memory b for currently received program data includes data #1 and #1 that constitute each received program. #2. #3.
. . , #n packet data are each stored in memory. Note that one packet data consists of 22 bytes, and the entire memory has a capacity of, for example, 300 packets.

Next, it is determined whether the error correction is completed in the same manner as in step 21 described above [step 29], and if the correction is completed [yes], it is determined whether the packet is of the desired program or not [step 29]. Step 30] If it is a packet of the desired program [yes], it is determined whether there is an error remaining in the packet [Step 311] The error correction is performed in the buffer 7 memory 6 as information from the error correction circuit 5. As a result, it contains information on whether errors remain in the packet or whether they have been corrected, so if there are errors in the packet, select [yes].
When the remaining error packets are stored in the currently received program data memory, the data (counter) in the currently received data error packet number memory is incremented by '+1' [step 32].

Then, the data in the memory for the total number of packets received this time (
Counter 1) also stores the received packet l+111j in the current received data memory [step 33]. At this time, it is checked whether it is the last packet 1 or more of the desired program [step 34], and if it is not the last packet [no], the process returns to step 29 and the same procedure is executed.

In this way, the packet data is sequentially stored in the current (latest received) iS set data memory. At the same time, each time a packet is stored in memory, the total number of packets received this time (memory data counter) is increased by 1".
I will do it. This process is continued until the last packet of the desired program is reached, and all data of one program is received (that is, stored in memory).

Also, one program (specific program) has approximately 20 to 30
Since it is repeatedly transmitted from the broadcasting station at intervals of seconds, the data received last time (approximately 20 to 30 days) is stored in the memory for previously received program data, and the number of error packets from the previous time is stored as the number of error packets in the previous received data. The previous total number of packets is stored in the memory (counter value) and the previous received data total packet number memory (counter value).
counter value).

In step 34, if it is the last packet of the desired program [yes], the packet error rate (=
(Number of error packets of data received last time) ÷ (Total number of packets of data received last time)) and data (packets) received this time
The packet error rate (=(number of error packets of currently received data)/(total number of packets of currently received data)) is calculated respectively [step 35].

Then, the previous packet error rate and the current packet error rate are compared [Step 36], and if the previous error rate is greater than or equal to the current error rate, [≧1, as usual, the currently received program data memory, the currently received data error Contents (data) of packet number memory and current received data total packet number memory
are transferred to the previously received program data memory, the previously received data error packet number memory, and the previously received data total packet number memory, respectively, and the previously received program data is newly replaced with the currently received program data [Step 37] ,
The program data received this time is used as new program data, and the data is transferred to the read image display memory 12, and the program data received this time is displayed on the screen in the display Vl position 13 [step 38].

Conversely, in step 3G, if the previous error rate is smaller than the current error rate, [<], the program data received this time (i.e., the contents of the memory for program data received this time)
is not transferred to the previously received program data memory, the currently received program data is not displayed on the screen, and the previously received program data is left displayed on the screen on the display device 13.

As described above, the error status (error bucket l−
If there are fewer errors this time than the last time, the program data received this time will be displayed on the screen, but if there are more errors this time than the last time, the program data received last time will be displayed as is. The program data received this time will not be displayed on the screen.

Therefore, in the embodiment of the present invention, for example, in a one-page repetitive program, a screen with fewer errors is displayed, and the recipient is less likely to be provided with an incorrect screen. In addition, for programs such as bulk desired programs, in which data that has been received once is stored in an adapter (receiver (i-device)) and then displayed on the screen based on the stored data, conventional devices may generate incorrect data. If the recipient receives (stores) the program and does not receive it again (in other words, does not operate the program selection key again to select the program again), the recipient must continue to view the wrong screen. However, in the embodiment device of the present invention, if incorrect data is initially received (
Save! ? 1) Even if an incorrect screen is displayed, if data with fewer errors is received, the display can be redisplayed on a screen with fewer errors without any operation.

(Effects of the Invention) As described above, according to the teletext receiving device of the present invention,
This method has the advantage that it is possible to reduce the display of erroneous screens, and it is possible to reduce the possibility of giving incorrect information to recipients.

[Brief explanation of drawings]

FIG. 1 is a block system diagram showing an embodiment of a teletext receiving device according to the present invention, FIG. 2 is a flowchart for explaining the operation of the present invention, and FIGS. FIG. 3 is a diagram showing the configuration. DESCRIPTION OF SYMBOLS 1... Input terminal, 2... Binarization circuit, 3... Clock regeneration circuit, 4... Synchronization detection circuit, 5... Error correction circuit, 6... Buffer memory, 7...・Microcomputer (CPIJ), 8... Desired program number import unit, 9... Remote control transmitter, 10... Work memory (
RAM), 11... Program memory, 12... Image display memory, 13... Display device. > writing on the drawing (no change in content) 72 Mouth (f no. 1) Engraving of drawing (no change on content) Sai 2 Mouth Drunk 2) Sai , (fan f4E1 procedure amendment writing method) % formula % 1, incident 3.Relationship with the case of the person making the amendment Patent applicant address: 3-chome Moriya-cho, Kanayō-ku, Yokohama-shi, Kanagawa Prefecture] 12 April 22, 1986 (shipping date) 5. Amendment Target drawings. 6. Contents of correction

Claims (1)

[Scope of Claims] A teletext receiving device that receives character signal packets superimposed within a vertical blanking period of a television signal, comprising: error detection means for detecting errors in the character signal packets; and the error detection means. a counting means for counting the number of erroneous character signal packets detected in each received program consisting of a plurality of character signal packets; and a memory for sequentially storing the number of erroneous character signal packets for each received program counted by the counting means. a count value of erroneous character signal packets of the latest received program stored in the memory means, and a count value of erroneous character signal packets of received data related to said one received data stored at least previously; What is claimed is: 1. A teletext receiving apparatus comprising: a control means for comparing the numerical values and controlling the received data having the smaller count value to be read and displayed.