JP2720456B2 - Teletext receiver - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a teletext receiving apparatus which receives and decodes text and graphic information multiplexed and transmitted on a television broadcast and displays it on a display unit.

2. Description of the Related Art In recent years, various television multiplex broadcasts have been considered in order to make effective use of broadcast radio waves. One of such multiplex broadcasts is a home-based news such as text and graphics, a weather forecast, and a stock market. Television teletext broadcasting capable of displaying text and graphic information on the screen of a television receiver has been put to practical use.

Hereinafter, with reference to the drawings, a description will be given of a teletext receiver capable of receiving the above-described text and graphic information and displaying the text and graphic information on a screen of a television receiver.

FIG. 5 shows a configuration of a conventional teletext receiving apparatus. In FIG. 5, 1 is a character / graphic information decoding unit for decoding character / graphic information into a character / graphic image, 2 is a microprocessor circuit for controlling the character / graphic information decoding unit, and 3 is
A receiving circuit 4 for extracting character / graphic information and program index data from the video signal as digital data. ROM for storing a program for controlling the
Is a display memory for storing a character / graphic image decoded by the microprocessor circuit 2, 6 is a display processing circuit for synthesizing the character / graphic image stored in the display memory 7 with an RGB signal, and 9 is A character generator used for decoding character / graphic information into a character / graphic image, 8 is an additional sound decoder for processing additional sound data included in the character / graphic information, and 10 is a character / graphic information decoding unit. It is a keypad for instructing selection of graphic information and the like. Reference numeral 20 denotes a television signal receiving unit, 21 denotes an antenna, 22 denotes a television signal receiving circuit, 23 denotes an audio demodulation amplifier circuit, 24 denotes a luminance amplification color demodulation circuit, 25 denotes a television video / audio signal, and character / graphic information. A video / audio switching circuit for switching or mixing an RGB signal and an additional audio signal output from the decoding unit 1, 26 is an audio amplification output circuit, 28 is a speaker, 27 is a video amplification output circuit, and 29 is a video display. It is a display unit.

Regarding the teletext receiving apparatus configured as described above,
The operation will be described below. The television signal received by the antenna 21 is demodulated by a television signal receiving circuit 22 of the television signal receiving section 20, and a video signal and an audio signal are extracted. The video signal is input to the receiving circuit 3 of the character / graphic information decoding unit 1 and extracts character / graphic information from the video signal. The user operates the keypad 10 to instruct the microprocessor circuit 2 to select a desired character / graphic information program from many character / graphic information programs. The microprocessor circuit 2 selects the designated character / graphic information program, stores the selected program in the RAM 4, and performs the decoding process while using the character generator 9 as necessary according to the contents of the program stored in the ROM 5. Then, the image is converted into a character graphic image and stored in the display memory 7. The character / graphic image stored in the display memory 7 is synthesized into an RGB signal by the display processing circuit 6. The additional sound data included in the character / graphic signal is converted by the additional sound decoder 8 into an additional sound signal.

On the other hand, the audio signal and the video signal demodulated by the television receiving circuit 22 are input and processed by an audio demodulation amplifier circuit 23 and a luminance amplification color demodulation circuit 24, respectively.
Is input to The video / audio switching circuit 25 switches between a video signal (RGB signal) and an audio signal (additional sound signal) output from the text / graphic information decoding unit 1 and a television video signal and audio signal, thereby converting the text / graphic image. The former is selected when displaying, and the latter is selected when displaying a television image, and the audio amplification output circuit 26 and the video amplification output circuit 27 are selected.
Through the speaker 28 and the display unit 29, respectively. With the above operation, the user can cause the display unit 29 to display the selected character / graphic information.

In teletext broadcasting, program index data is transmitted for each used scanning line at a standard cycle of 20 seconds and a maximum cycle of 30 seconds. The program index data includes information on the magazine number and the program number of the character / graphic information multiplexed on the scanning line.

The microprocessor circuit 2 decodes the program index data and causes the RAM 4 to store the magazine number and the program number of the character / graphic information multiplexed on the scanning line.

The magazine number and the program number stored in the RAM 4 are used when the keypad 10 is operated to search character / graphic information.

For example, by selecting and decoding the character / graphic information in ascending order of the program numbers stored in the RAM 4, the character / graphic information actually transmitted can be searched in ascending order of the program numbers.

SUMMARY OF THE INVENTION However, in the teletext receiving device having the above-described configuration, a period from power input to reception of index data or a period from a channel change to reception of index data, Alternatively, if the index data is not sent, the character / graphic information cannot be indexed in the order of the program number because the program number is unknown even though the character / graphic information is sent. Was.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides a character / graphic information display device capable of searching character / graphic information in the order of program numbers without receiving index data.

Means for Solving the Problems In order to achieve this object, a teletext receiving apparatus of the present invention comprises: a memory capable of writing and reading at least 3 × 10 ⁴ bits of information in 1-bit units; Specify three areas with a size of ⁴ bits or more, and specify 0000 to 9999, which is determined by the magazine number and program number of teletext.
^Four 10 ⁴ addresses corresponding to four digits and the address generating means for generating for each of the three areas on the memory, with respect to three areas of the memory, for writing one of them Specify the other one for reading and writing, specify the other one for erasing, and specify the area that had been used for writing for reading and writing each time a certain time elapses A memory area use designating means for designating an area for reading and writing as for erasing and designating an area for erasing as for writing; and data in the erasing area until the predetermined time elapses. And a time measuring means for measuring the predetermined time.

According to the present invention, the magazine number and the program number included in the character / graphic information can be stored in the memory by the above-described configuration, and the transmitted program number can be known without using index data. Further, the magazine number and the program number stored in the memory are always updated by the memory area use designating means and the erasing means. For example, if the transmission of the character / graphic information program of a certain program number is stopped, it will take a while. , The program number disappears from memory. In this way, character and graphic information can be searched in the order of program numbers using the program numbers stored in the write and read areas of the memory.

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows the configuration of a teletext receiving apparatus according to an embodiment of the present invention. In FIG. 1, 3
Is a receiving circuit, 4 is a RAM, 5 is a ROM, 6 is a display processing circuit, 7
Is a display memory, 8 is an additional sound decoder, 9 is a character generator,
10 is a keypad, 20 is a television signal receiving unit, 21 is an antenna, 22 is a television signal receiving circuit, 23 is an audio demodulation amplifier circuit, 24 is a luminance amplification color demodulation circuit, 25 is a video / audio switching circuit, and 26 is audio. Amplification output circuit, 27 is a video amplification output circuit,
Reference numeral 28 denotes a speaker and 29 denotes a display unit, which has the same configuration as that of FIG.

2 is a memory area use specification means 11 and an address generation means
12 is a microprocessor circuit. 14 is a first timer for measuring a time of 20 seconds, and 15 is a second timer for measuring a time of 1 second. Reference numeral 13 denotes a memory capable of reading and writing 6 Kbytes of data.

Regarding the teletext receiving apparatus configured as described above,
The operation will be described below.

The teletext receiving apparatus of this embodiment can basically perform the same operation as the conventional teletext receiving apparatus of FIG.

FIG. 2 is a diagram showing the assignment of addresses of the display memory 7 by the address generating means 12 in FIG. 6K
An address is assigned to a byte (6144 bits) memory 7 in units of 2 bytes (16 bits). In FIG. 2, a is a first area having an address in the range of 0000 to 0999 in decimal, b is a second area having an address in the range of 1000 to 1999, and c is an area in the range of 2000 to 2999. A certain third
And d is an unused area.

FIG. 3 is a diagram showing the allocation of each bit of 2-byte (16 bits) data which is a unit for allocating the address of the display memory 7. In FIG. 3, e is the first byte,
f is the second byte. The first byte uses all eight bits. The second byte uses only 2 bits and the remaining 6
Do not use bits.

The address generating means 12 shown in FIG. 1 stores a three-digit number of four digits from 0000 to 9999 given by a magazine number and a program number, that is, 000 to 999 as addresses of the memory 13, 000 to 9
Correspond to 99,1000-1999,2000-2999. Further, the remaining one-digit numbers 0 to 9 are made to correspond to the first to tenth bits of the two bytes of the unit for allocating the address.

FIG. 4 shows a memory used by the memory area use specifying means 11.
FIG. 13 is a diagram showing designated transitions for 13 regions (a, b, and c in FIG. 2). In FIG. 4, (a) is a first state in which the first area a is used for writing, the second area b is used for reading and writing, and the third area c is used for erasing. A second state in which the area a is for reading and writing, the second area b is for erasing, and the third area c is for writing,
(C) is a third area where the first area a is used for erasing, the second area b is used for writing, and the third area c is used for reading and writing.
It is a state of.

The memory area use specifying means 11 switches the three states (A), (A) and (C) every 20 seconds measured by the first timer 14.

The microprocessor circuit 2 reads a magazine number and a program number included in the character / graphic information, obtains an address corresponding to the magazine number and the program number, and stores the address in the write area and the write / read area of the memory 13.

Each time the second timer 15 measures one second, the microprocessor circuit 2 reduces the data in the erasing area of the memory 13 by 1/20.
Erase every range. After 20 seconds, all data in the erasure area is erased.

The microprocessor circuit 2 obtains an address corresponding to the magazine number and the program number by the address generating means 12 and reads the data in the write / read area of the memory 13 to determine whether or not the program has been transmitted.

As described above, according to the present embodiment, by including the memory area use specifying unit 11, the address generating unit 12, the first timer 14, the second timer 15, and the memory 13, even if index data is not used, The presence / absence of the transmitted program can be known, and the character / graphic information can be searched in the order of the program number.

As described above, according to the present invention, at least 3 × 10 ⁴ bits of information can be written and read in 1-bit units, an address generating means, a memory area use specifying means, and an erasing means. By providing the time measuring means, the program number transmitted without using the index data can be known, and the character / graphic information can be searched in the order of the program numbers without using the index data.

[Brief description of the drawings]

FIG. 1 is a block diagram of a teletext receiving apparatus according to an embodiment of the present invention, FIG. 2 is a diagram showing allocation of memory by address generation means, and FIG. 3 is a diagram showing allocation of each bit of 2-byte data in the memory. FIG. 4 is a diagram showing transition of memory area designation, and FIG. 5 is a block diagram showing a configuration example of a conventional teletext receiving apparatus. 2... Microprocessor circuit, 11... Memory area use designation means, 12... Address generation means, 13.
... A first timer, 15... A second timer.

Continued on the front page (72) Inventor Toyoaki Unemura 1006 Kazuma Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. (72) Inventor Ken Sakamoto 1006 Kazuma Kadoma, Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. (56) References JP-A-61-3587 (JP, A)

Claims (1)

(57) [Claims] A memory which can perform writing and reading in units of 1 bit and is used by designating three areas;
Address generating means for generating an address corresponding to a magazine number and a program number included in the received text / graphic information of the teletext for each of the three areas of the memory; time measuring means for measuring a predetermined time; A memory area use designating means for designating the three areas as a write area, a read / write area, and an erase area, and periodically changing the designation by the time measuring means; Storing a magazine number and a program number in the writing area specified by the above, and when the transition to the erasing area after a specific time measured by the clock measuring means, the magazine number and the program number are erased. Teletext receiver.