JP2596424B2 - Teletext receiver - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a teletext receiver for receiving and displaying a text multiplexed signal multiplexed during a vertical blanking period of a television video signal.

(Prior Art) In recent years, teletext broadcasting in which text information is multiplexed during a vertical blanking period of a television video signal has been put to practical use and has begun to spread. As a receiver for receiving the teletext, there is, for example, a receiver having a circuit configuration shown in FIG.

This consists of a receiving antenna 1, a tuner 2, a VIF detection circuit 3 for amplifying and detecting the intermediate frequency signal as a television receiving system, a video amplifying circuit 4 for removing an audio signal component from the detected signal and amplifying a video signal component, Audio demodulation circuit 5, which extracts audio signal components from the circuit, demodulates and amplifies, and speaker
6, a channel selection circuit 7 for changing the television channel, and a color signal component in the video signal from the video amplification
A color reproduction circuit 8 for demodulating to Y, G-Y signals, an RGB conversion circuit 9 for creating an RGB signal from this circuit and an input signal from the video amplification circuit 4, and a video signal from the video amplification circuit 4. It comprises a synchronizing circuit 10 for separating and producing a horizontal synchronizing signal and a vertical synchronizing signal, a deflecting circuit 11 of a cathode ray tube 13, and a switching circuit 12. Further, a character signal extracting circuit 14 for extracting a character signal in the video signal from the video amplifier circuit 4 and converting it into a digital signal as a character signal display. The character signal for one field in the digitalized video signal is temporarily stored. A character signal recording memory 15 for storing, a processing / processing of a command from the operation unit 17 for the character signal, a control microcomputer 16 for giving a command to the display control circuit 20 and the channel selection circuit 7,
The program ROM 18 in which the program of the control microcomputer is stored, the teletext data is stored in the text signal recording memory
A main memory 19 having a function of reading one screen every field from 15 and a function for work of the control microcomputer 16, a display control circuit 20 for performing display control based on text broadcast data from the control microcomputer 16, Kanji ROM2 in which characters such as Kanji, Hiragana, Katakana, and alphanumeric characters are recorded
1, a display memory 22 in which display data is recorded.

An operation unit 17 for selecting a TV channel and requesting a teletext program, and switches between a TV color signal and a teletext signal by the switching circuit 12 and inputs the signal to the CRT 13. is there.

Describing the operation of this receiver, the user
The television channel on which the text broadcast is transmitted by 17 is commanded to the control microcomputer 16 and the microcomputer operates the tuner 2 by the channel selection circuit 7 to select a channel. As is well known, a television image is displayed on the CRT 13. You. On the other hand, a video signal from the video amplification circuit 4 is applied to a character signal extraction circuit 14. Then, when a teletext program is requested by the operation unit, the control microcomputer 16 causes the text signal sampling circuit 14
The contents of the teletext information digitally processed in step (1) are recorded in the character signal recording memory 15 for each field to search for the program number of the teletext.

In this case, the requested program and the character signal recording memory
If the received data in 15 matches, check the data length in the packet, the continuity of the packet, and the type of packet.
If the packet is of the same type as the program coincidence data, it is sequentially recorded in the main memory 19 to record packet data for one screen. Further, it sequentially analyzes the packet data and controls the display control circuit 20 to output a switching signal for one character broadcast of television to the switching circuit 12. As the switching signal, there are a method of superimposing and switching a teletext broadcast signal, and a method of entirely switching to a teletext broadcast. Further, the control microcomputer 16 sequentially analyzes the packet data,
The color data is recorded in the display memory 22 via the display control circuit 20. The character code information is converted into a character pattern by the kanji ROM 21 via the display control circuit 20 and sequentially recorded in the display memory 22. The information recorded in the display memory 22 is transmitted to the switching circuit by the display control circuit 20.
It is displayed on the cathode ray tube 13 via 12.

By repeating the above operation, the character information is
Will be displayed.

(Problems to be Solved by the Invention) In the configuration of the conventional receiver described above, the main power of the receiver is turned on, the user requests a teletext program on the operation unit 17, and then the actual broadcast is displayed on the CRT 13. Before it appears on
This requires repetition of the above-described operation, and takes a considerable amount of time. Therefore, the content of the program to be used, for example, stock price information is required to be displayed immediately, but is not satisfied. In addition, there is a demand that the teletext table of contents set for each television channel be displayed instantaneously. When selecting a teletext program,
After switching the channel of each television, a teletext table of contents or the like is received and displayed to request a target teletext program, so that troublesome work such as changing channels is required. In addition, an expensive memory is required as a memory for storing a text broadcast table of contents, which is not economical.

(Object of the Invention) The present invention solves the problems as described above, and if a program is requested while viewing a table of contents image of a teletext, it is possible to change up to each television channel and display it immediately. Thus, an object of the present invention is to provide a teletext receiver that can perform the same function even when the amount of information and the number of channels in the table of contents increase.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a teletext receiver for receiving and displaying a text multiplexed signal multiplexed during a vertical blanking period of a television video signal. Storage means for storing program index information for guiding the contents of a program such as a table of contents in a character multiplex signal in association with the channel number of each television channel through which the multiplex signal is transmitted; An operation unit for requesting a broadcast program, a channel selection circuit for selecting a television channel, a display control circuit for displaying an input signal on a video, and the operation unit based on the displayed program index information. When a teletext program is selected in the operation section, a television channel number corresponding to the teletext program selected in the operation section is read out from the storage means, Control means for controlling the channel selection circuit and the display control circuit so as to select a Levi channel and display a teletext program selected on the operation unit on a screen.

Further, the teletext receiver includes a backup memory in which the stored contents are retained even when the main power of the teletext receiver is turned off, and a main memory in which the stored contents are not retained. When the program index information or the like stored in the memory overflows, the program index information is transferred to the main memory. When the main power is turned off from the on state, the program index stored in the backup memory is transferred. Information and the like are displayed by instruction control of the operation unit.

(Operation) According to the present invention, the control unit reads out the teletext information and the channel information in the memory in accordance with the instruction of the operation unit, and displays them on the display unit. When a request for a broadcast program is made, the control unit changes the channel to the channel based on the channel information stored in the memory, so that the desired text broadcast program is immediately displayed by a simple operation. is there.

(Embodiment) FIG. 1 shows a circuit configuration of an embodiment of the present invention, in which the same reference numerals as those in FIG. 4 are the same.

The present invention includes a low power consumption backup memory 23 composed of, for example, 32 Kbytes, and a time monitoring timer 24.
And a battery 25 as a power supply for these circuits is provided in a conventional circuit. Here, the backup memory 23, which is always supplied with power from the battery 25, stores, in the character multiplexed signal of the television image signal, the program index information for guiding the program contents such as the table of contents and the television channel being selected. The number is stored. Therefore, even if the main power supply of the receiver is turned off, the stored state is maintained by the battery, and the timer 24 sends out the time information, and the control microcomputer 16
Read this.

Next, the operation of the present embodiment will be described, but portions overlapping with the conventional operation will be omitted. When the user instructs the control microcomputer 16 on the channel on which the text broadcast is being transmitted by the operation unit 17 and the microcomputer activates the tuner 2 by the channel selection circuit 7, a television image is displayed on the CRT 13. You. A video signal is output from the video amplifying circuit 4, is digitally processed by a character signal extracting circuit 14, and is superimposed on an arbitrary multiplex H of 10H to 21H (H is an aqueous scanning period) in a vertical blanking period. Broadcast information is stored in each multiplex H
Is recorded in the character signal recording memory 15 in accordance with.

Since the content of the character signal recording memory 15 is updated every field, the control microcomputer 16 reads the information of the recording memory 15 at a time other than the recording time of the character signal recording memory 15, and the information content is represented by the table of contents information. If there is, the received table of contents data is sequentially compared with the table of contents data of the corresponding channel recorded in the newly attached backup memory 23, and if they match, the recorded contents of the backup memory 23 are not updated. Read the time information from the timer 24,
Only the data of month, day, hour, and minute in the recorded contents of the backup memory 23 are updated.

Also, in the comparison operation, if the stored contents are different from the table of contents data, the control microcomputer 16 determines that the table of contents data has been updated, and replaces the next transmitted table of contents data with the old table of contents data. Is recorded in the same memory area. The table of contents data of a new channel is recorded up to the management number, channel number,... Table of contents information as in the memory map shown in FIG.

In actual broadcasting, the capacity of the table of contents data is usually transmitted within 200 packets, that is, within a memory area of about 4.8 Kbytes.
Since the capacity of K bytes is used, the contents data of the text broadcast for 6 channels can be recorded. The contents of the table of contents are almost fixed every day, and the amount of the table of contents data to be transmitted is almost the same. However, considering that there is some variation, a spare area of 880 bytes per channel (FIG. 2) Is provided.

As described above, the table of contents data of six or more channels can be normally recorded, but the data amount of one screen can be up to 300 packets in specification and the memory capacity can be up to 7.2 Kbytes. For example, when the table of contents of 14 channels has three pages, a memory capacity of 21.6 Kbytes is required, and there is a possibility that only the table of contents for one channel can be recorded. In this case, the table of contents data of the overflowed channel is transferred to the main memory 19, and the updated channel is not recorded in the backup memory 23 in both the backup memory 23 and the main memory 19. The table of contents data is recorded sequentially.

In the operation so far, when the main power of the teletext receiver is once turned off and then turned on again to view the teletext, the following is performed. If you select the table of contents data on the operation unit 17 and select a teletext program, the control microcomputer
The reference numeral 16 immediately reads the chamber number from the backup memory 23 which is always stored in the battery 25, changes the channel, and requests a teletext program. If there is a significant difference from the date and time information of the timer 24, as shown in FIG. 3, the date and time when the table of contents data is recorded is displayed in the header to indicate that the information is old. Display messages and so on.

As described above, according to the present embodiment, the main power of the teletext receiver is turned on by recording the table of contents data, the channel number, the recording time, and the like of each channel in the backup memory 23, which is always readable. In addition to instantaneous viewing, the user can select a program while looking at the table of contents, thereby making it possible to change the channel. Further, even when the index data of each channel increases and overflows the capacity of the backup memory 23, the transfer to the large-capacity main memory 19 does not hinder the operation.

(Effects of the Invention) As described above, the present invention provides a conventional teletext receiver provided with a backup memory for storing table-of-contents data and the like of each channel and a timer for transmitting time information by a simple means. By immediately requesting a program while viewing the text broadcast table of contents, the channel is automatically selected and the text broadcast is displayed. Moreover,
With the backup memory and the main memory, even if the amount of information and the number of channels in the table of contents increase, overflow processing is performed and the function can be operated normally.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of one embodiment of the present invention, and FIG.
FIG. 3 is an example of a memory map of the backup memory 23 shown in FIG. 3, FIG. 3 is an example of the screen display of FIG. 1, and FIG. 4 is a circuit configuration diagram of a conventional teletext receiver. 2 ... Tuner, 3 ... VIF detection circuit, 4 ... Video amplification circuit, 5 ... Audio demodulation circuit, 7 ... Tuning circuit, 12 ... Switching circuit, 13 ... CRT,
14 ... Character signal extraction circuit, 15 ... Character signal recording memory, 16 ... Control microcomputer, 17
…… Operation unit, 19 …… Main memory, 20 …… Display control circuit, 23
…… backup memory, 24 …… timer, 25 …… battery.

Claims (2)

(57) [Claims] In a teletext receiver for receiving and displaying a character multiplex signal multiplexed during a vertical blanking period of a television image signal, the character multiplex signal is made to correspond to a channel number of each television channel through which the character multiplex signal is transmitted. Storage means for storing program index information for guiding the contents of a program such as a table of contents in a text multiplex signal, an operation unit for selecting a TV channel and requesting a text broadcast program, and selecting a TV channel. A channel selection circuit, a display control circuit for displaying an input signal on an image, and a teletext program selected by the operation unit based on the displayed program index information. The TV channel number corresponding to the selected teletext program is read out from the storage means, and the TV channel is tuned in and selected by the operation unit. The character broadcast program to screen display, teletext receiver characterized by a control means for controlling the tuning circuit and the display control circuit. 2. A backup memory which retains stored contents even when a main power supply of a teletext receiver is turned off,
A main memory that does not hold the stored contents, and when the main power is turned on, when the program index information or the like stored in the backup memory overflows, the main memory is transferred to the main memory. 4. The method according to claim 1, wherein when the program is switched from the disconnected state to the activated state, the program index information and the like stored in the backup memory are displayed under instruction control of an operation unit. Teletext receiver.