JP2003339014A - Broadcast receiving apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a broadcast receiving apparatus for flexibly managing the storage/erasure of data by managing the page data of a teletext program as one file in the case of storing the data of the teletext program. <P>SOLUTION: Teletext is received; teletext data are extracted by a character signal sampling part 3, the teletext data of one teletext program at least are selected by a teletext program selecting memory, and the selected teletext data are stored in a data storage part 6 managed by a memory managing part 7 by a file management part 8 as one file for each of page data. Namely, since the memory is allocated for each file, the teletext data are not forcibly erased like a ring memory but a user can view the desired teletext program without waiting. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention When viewing a data broadcast program such as a text broadcast, the present invention not only views the program data being received, but also efficiently stores the program data to allow an arbitrary program to be displayed. The present invention relates to a teletext receiver and a method thereof that can be freely selected and viewed.

[0002]

2. Description of the Related Art In recent years, a coded transmission system capable of displaying news, weather forecasts, stock market, and other text and graphic information consisting of text and graphics on the screen of a home television receiver by using broadcast radio waves. Has been put into practical use, and a television receiver with a built-in receiving device for receiving the character broadcast of this coded transmission system has also been developed.

Below, regarding the conventional teletext receiver,
A description will be given with reference to the drawings. FIG. 14 shows the configuration of a conventional teletext receiver. 141 in FIG.
Is a CPU that controls the entire system, and 142 is a storage unit that holds an operation program. a is a video signal of the television, 143 is a character signal extracting unit for extracting the character broadcast data superimposed on the vertical blanking interval from the video signal a, and 144 is decoding of the character broadcast data extracted by the character signal extracting unit 143. Is a decoding unit that performs the above process and develops into display data of a character graphic for display. 145
Is a data storage unit for storing only the teletext data extracted by the text signal extraction unit 143, 146 is a memory management unit for managing the teletext data according to the control code of the teletext data in the data storage unit 145, and 147 is A display memory for holding display data expanded into a character graphic by the decoding unit 144, a display control unit 148 for performing memory address control for fetching display data from the display memory 147, and a reference numeral 149 for reading teletext data from the display memory 147. It is a TV monitor for actual display.

The operation of the teletext receiving apparatus configured as described above will be described below. The teletext signal extracting unit 143 extracts vertical blanking intervals 14H (277H) and 15H (278) from the input video signal a.
H), 16H (279H), and 21H (284H), the character signals superimposed on the four transmission lines are extracted.

Twenty-two bytes of the teletext data are superimposed on the transmission lines of the four vertical blanking intervals (22-byte data is one packet).

Details of the standard relating to teletext are described in "Teletext Broadcasting Handbook, Broadcasting Technology Development and Development Council, Kenrokugen Publishing". The definitions of "program" and "page" described in the specification follow this teletext technical handbook.

The CPU 141 stores the extracted teletext data in the data storage unit 145 via the memory management unit 146. In addition, the CPU 141 uses the data storage unit 145.
To read the teletext data from the memory management unit 146. Then, the decoding unit 144 converts the data into character / graphic data (display data) for displaying characters and graphics on the television monitor, and writes the character / graphic data in the display memory 147. The display control unit 148 reads the character graphic data from the display memory 147 and displays it on the television monitor 149.

The CPU 141 has a function of preferentially accumulating reserved teletext programs in the data storage unit 145. Further, the teletext data that is sequentially received is stored according to the remaining memory capacity of the data storage unit 145.

A method of controlling the data storage unit 145 by the memory management unit 146 will be described below with reference to FIGS. 15, 16 and 17. Figure 15 shows
The internal configuration of the data storage unit 145 and the memory management unit 146 includes N memory blocks for storing sequentially received teletext data for each packet and a position table for managing the memory blocks. The position table is
There is a one-to-one correspondence with the memory block, and a ring memory is formed for the memory block.

That is, the position table 1 indicates the position table 2, the position table 2 indicates the position table 3, and the position table N indicates the position table 1. The teletext data sequentially received is written in the ring memory. In the ring memory, the received teletext data is stored in the data storage unit 1
When the memory capacity of 45 is exceeded, new data is sequentially updated from the memory block in which old teletext data is stored.

FIG. 16a shows a packet format for actually storing sequentially received packet data in a memory block, which consists of programs, page information and packet data.
As described above, the packet data is stored from the one received sequentially. At this time, in the packet data, since the content of the teletext program is not continuous, the packet format requires the program and page information.

FIG. 16b is an internal view of the memory when the packets are sequentially stored in the memory block. When the second page of the program 5 is displayed on the television monitor, the second page of the program 5 is searched from the program and page information in the memory block, the packet data is expanded by the decoding unit 144 into a character graphic, and the display memory 147 is displayed. Transfer to.

At this time, if the second page of the program 5 does not exist in the data storage section 145, it waits until the data is sent.

Next, the case of reservation will be described with reference to FIG. FIG. 17 shows the data storage unit 1 when reservation is used.
In the internal configurations of the memory management unit 45 and the memory management unit 146, a reservation table is added to the content shown in FIG. When a user reserves a teletext program, the program is prioritized and stored in the memory. The reservation table is composed of reserved programs and the numbers of memory blocks that are prioritized. FIG. 17 shows that when the program number 100 is reserved, the memory blocks 1 and 2 are secured, and the memory blocks 1 and 2 and the remaining memory blocks 3 to N respectively form separate ring memories. There is.

When a reserved teletext program is displayed on the television monitor, a page is retrieved from the memory reserved for reservation, and the decoding unit 144 develops it into a character graphic and transfers it to the display memory 147.

As described above, the conventional teletext receiver stores and displays teletext programs.

[0017]

However, the conventional device has two problems. One is that the memory management of teletext programs is not sufficient. This is to manage the data storage unit in a ring memory format and to manage the teletext program as a file in order to improve the memory usage efficiency. I was in control. Therefore, when accessing a page of an arbitrary teletext program, packets of the page data are collected and displayed. Further, in the ring memory, when the memory is full, old data is erased in order, so that it is impossible to manage the presence or absence of page data.

Another problem is the cost of memory capacity. For example, if all NHK teletext programs are stored in the memory, at least about 1 MB is required. In the conventional device, only a memory of about 200 Kbytes is installed to store teletext programs, and it is costly to install a memory of 1 Mbyte.

The present invention has been made to solve the above-mentioned conventional problems. In order to solve the memory management problem and the memory capacity problem of a teletext program, a plurality of pages of the teletext program are treated as one file. Manage files. Then, by compressing and storing, the apparent memory capacity was increased. Also, when managing files, the memory usage efficiency is set to the same level as the ring memory format.
An object is to provide a teletext receiver and a method thereof.

[0020]

In order to achieve this object, a teletext receiver of the present invention comprises a signal extraction means for receiving radio waves and extracting teletext data, and a means for extracting the teletext data extracted. Among them, a teletext program selection means for selecting teletext data of at least one teletext program, a data storage means for accumulating the selected teletext data, and a page of the teletext data as one file. A file managing means for managing, a data compressing means for compressing the file to create a compressed file,
A data decompression unit that decompresses a compressed file to create a decompression file, and a plurality of pages of files included in one program managed by the file management unit are grouped by a predetermined number of files based on the compression processing time. Equipped with file archive means to create archive files,
The archive files collected by the file archive means are compressed by the data compression means.

According to the present invention having such features,
The memory usage efficiency can be maximized. Also,
By using file management, it is possible to flexibly manage broadcast programs.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION (Embodiment 1) Hereinafter, FIG.
The first embodiment of the present invention will be described with reference to FIGS. In FIG. 1, 1 is a CP that controls the entire system
U and 2 are storage units for holding operation programs. Reference numeral 3 is a character signal extracting unit for extracting the character broadcasting data superimposed on the vertical blanking section from the video signal a, and 4 is for selecting necessary data from the character broadcasting data extracted by the character signal extracting unit 3. The teletext program selection unit 5 is a decoding unit that decodes the teletext data selected by the teletext program selection unit 4 and develops the data into display data of a character graphic to be displayed. 6 is a data storage unit for storing the teletext data selected by the teletext program selection unit 4, 7 is a division of the data storage unit 6 into small blocks,
A memory management unit for managing the usage status and link information of the block, 8 is a file management unit for managing file creation and deletion with the "page" unit of the teletext program as the minimum file unit, and 9 is the decoding unit 5 A display memory 10 for storing display data expanded into a character graphic, a display controller 10 for controlling a memory address for fetching the display data from the display memory 7, and a television 11 for reading from the display memory 9 for actual display. It is a monitor.

The operation of the teletext receiving apparatus configured as described above will be described below with reference to FIGS. 2 and 3. The teletext signal extracting unit 3 extracts vertical blanking intervals 14H, 15H, 16H from the input video signal a.
The character signals superimposed on the four transmission lines of 21H are extracted. The teletext data is superposed by 22 bytes on each of the transmission lines of the four vertical blanking intervals (22-byte data is one packet).

From the extracted teletext data, the teletext program selection unit 4 selects only predesignated teletext programs (for example, programs reserved by the user). The selected program creates a file for each page of the program, and the file management unit 8 manages the page by page.

When the file management unit 8 creates a file, the memory management unit 7 secures one memory block in the data storage unit 6. After that, the file management unit 8 writes teletext data (packet data), and when the capacity of the memory block becomes full, the memory management unit 7 secures a new memory block.

FIG. 2 is an explanatory diagram in the case of actually writing teletext data (packet data) in the memory block. Since writing to the memory block is performed in packet data units, the size of the memory block is a multiple of the packet data.

In the present embodiment, one memory block can store 12 pieces of packet data, and this figure shows a state in which data for three pages is stored in the data storage unit 6. The first page data consists of 10 packets, the second page contains 6 packets, and the third page contains 15 packets. The memory management unit 7 is 1 for each of the data of 1 and 2
Blocks are acquired and 2 blocks are acquired for 3 pages of data.

FIG. 3 is an explanatory diagram of a case where a new file is created and data is written to the selected teletext data. In FIG. 3, the file management unit 8
The file table 7 includes a file name created by the file management unit 8 and a memory block number (memory management table number) indicating the first memory block of the data storage unit 6 that stores the file. The memory management table of the memory management unit 7 has a one-to-one correspondence with the memory blocks of the data storage unit 6, and stores the usage status of the memory blocks and the link information between the blocks. If the memory block is not used, "0" is stored. If the block is in use, the next linked block number,
Alternatively, if it is the final block, "-1" is stored.

In the case of FIG. 3A, the file management unit 8 creates a page file “name1” and stores it from the memory block 1 of the data storage unit 6. Figure 3
In (b), since the memory capacity of the memory block 1 is full, a new unused memory block 2 is acquired. Then, as the link information of the memory block, "2" indicating the next block is stored in the memory management table 1 in the memory management table, and "-1" indicating the last block of the file is stored in the memory management table 2. The same applies to the other page files “name2” and “name3”.

As described above, since all teletext program data can be managed in file units, when expanding an arbitrary file in the display memory 9, the access to the predetermined program data is more convenient than the conventional ring memory format. And get faster.

Further, since the teletext data is managed in units of files, even if the capacity of the data storage unit 6 becomes full, the old teletext data is forcibly ordered from the old teletext data like the ring memory format shown in the conventional example. Will never be deleted. That is, the CPU 1 can store / manage teletext data using the file management unit 8. As a method of deleting the file, a method of deleting from the teletext program file that the user is not currently viewing is conceivable.

(Second Embodiment) Hereinafter, FIG. 4, FIG. 5, and FIG.
The second embodiment of the present invention will be described with reference to FIG. FIG. 4 is an overall system configuration diagram according to the second embodiment,
1 to 7 and 9 to 11 are similar to the configuration of FIG. The difference from the configuration of FIG. 1 is that a page search function 8a is added to the file management unit 8. FIG. 5 is a memory internal configuration diagram of the data storage unit 6 in the second embodiment. The operation will be described below.

In the present embodiment, the case where the file unit is a "program" of teletext will be described with reference to FIG. When the teletext program is composed of three pages as in FIG. 3, the memory management unit 7 writes the first page,
Acquire one memory block. Then, the file management unit 8 actually writes in the memory. When writing the second page, the memory block can still write two packets, so the first two packets of the second page are written.
After that, a new memory block is acquired and the remaining 4 packets are written. The same applies to the third page. By using multiple pages as one file, the unused memory in the memory block can be reduced. (If the memory block is around 1 Kbyte, the page file management has a memory usage rate of about 70%. Then about 95%).

FIG. 6 shows the internal structure of the program file shown in FIG. The first page of the program file comprises a program data header indicating that the next data is program management data, and program management data such as the total number of pages of the program, the program data length, and the program form. The second page consists of a page data header indicating that the next data is the first page of the teletext program and the program data of the first page. The third page is the second page of the teletext program. It is composed of a page data header indicating that it is and the program data of the second page.

Since the data of the first page of this program file is the program management information for teletext, it is not necessary to manage it as page data (the same applies to the "page" file in other embodiments).

The page search function 8a shown in FIG. 4 can detect a predetermined page by searching the program data header and page data header in the program file from the top of the page.

As described above, the file management is performed for a plurality of "pages" (in this case, for each teletext program), so that the memory usage efficiency can be improved. When accessing a predetermined page, the page search function 8a
Can be used.

(Third Embodiment) The third embodiment of the present invention will be described below with reference to FIG. FIG. 7 is a configuration diagram for explaining file management when a file unit managed by the file management unit 8 of FIG. 1 is a “program” of teletext and a file / page conversion table is provided in the present embodiment. is there. Other than the file management unit 8, the description is omitted because it is the same as FIG. 1 which is the system configuration diagram of the first embodiment. The operation will be described below.

The file table of the file management unit 8 of FIG. 7 is similar to the file table of FIG. 3, and the file managed by the file management unit 8 and the number of the first memory block of the data storage unit 6 that stores the file. (Memory management table number) and a conversion table address indicating an address of the file / page conversion table as an additional function.

When a program file is created, a file / page conversion table for the file is created at the same time, and the start address of the file / page conversion table is stored in the conversion table address of the file table. Then, when the file management unit 8 writes the teletext data of the program file in the memory block, the page number and the page size are recorded in the file / page conversion table.

When the predetermined page is searched after writing the teletext program data in the memory block, the start address of the predetermined page can be obtained from the file / page conversion table without searching from the top of the page. Therefore, high-speed file access becomes possible.

For example, when the page number 3 is searched, the start address of the page data of page number 3 can be obtained by adding the page sizes of page number 1 and page number 2.

As described above, the file management unit 8 manages files for each program of teletext and has the file / page conversion table, so that high speed access to predetermined page data becomes possible.

The page size in the file / page conversion table may be calculated by storing the top address of each page in advance, or by omitting the page number and starting from the first page. Only the page size or the start address may be stored.

(Fourth Embodiment) The fourth embodiment of the present invention will be described below with reference to FIG. FIG. 8 is a configuration diagram when the file / page conversion table provided in the file management unit 8 of the third embodiment is incorporated in a program file. Except for the file management unit 8, the system configuration is the same as that of 1 to 7 and 9 to 11 in FIG. The operation will be described below.

The area for the file / page conversion table in the memory block of the data storage unit 6 of FIG. 8 is checked in advance by checking the page number of the program file with the program page header when the program file is created. The memory size used in the conversion table is secured from the beginning of the file in the memory block.

When the file management unit 8 writes the packet data of the program file in the memory block,
The page data header is detected and the page number and page size are recorded in the file / page conversion table.

With this method, it is not necessary for the file management unit 8 to provide a conversion table address for holding the file / page conversion table in the file table. Further, it is not necessary to hold the file for the file / page conversion table.

(Fifth Embodiment) The fifth embodiment of the present invention will be described below with reference to FIG. FIG. 9 is an overall system configuration diagram in the fifth embodiment, and 1 to 11 are the same as the configuration in FIG. The difference from the configuration of FIG. 1 is that a data compression unit 12 that compresses a program file managed by the file management unit 8 and a data decompression unit 13 that decompresses the compressed program file are added. Also,
The file management unit 8 may have any of the functions of the first to fourth embodiments, but in the present embodiment, it has the fourth embodiment.
The file management unit 8 having the function of will be described. The operation will be described below.

When the program file is displayed on the TV monitor, the operation of expanding the display data of the character graphic for display by the decoding unit 5 and transferring it to the display memory 9 to display it on the TV monitor 11 is carried out. It is the same as the form 1.

However, the program file of the file management unit 8 is not used except when it is displayed on the television monitor and when a program update occurs. Therefore, the program file can be compressed and stored in the data storage unit 6 after the creation of the program file is completed, thereby improving the efficiency of use of the memory. When a program update occurs, a program file is created again and compressed.

Received program file (uncompressed file)
When the storage of the program is completed, the data compression unit 12 compresses the program file, stores it as a compressed file, and deletes the uncompressed file.

When referring to a program file which is a compressed file, the data decompression unit 13 decompresses the compressed data and then expands it into display data of a character graphic to be displayed by the decoding unit 5. And is displayed on the TV monitor 11.

As described above, when the program file is compressed and stored using the compression algorithm, and only the required file is expanded, the storage efficiency of the memory can be increased by about 40% when the teletext data is stored. it can.

Huffman coding and "Lempel-Ziv (LZ) coding" are examples of compression methods for character data. The data compression method is described in "Data compression technology has become established in personal computers and large machines (Nikkei Electronics / 1993.5.10)". In the present embodiment, LZ encoding is used as the compression method. Recently, LZ encoding is often used as a compression method with a high compression rate. As an algorithm, compression is realized by registering a past character string as a dictionary, comparing the character string in this dictionary with the current character string, and finding a matching character string. This method requires a dictionary size of at least about 1 Kbyte.

Since the average length of each "page" of the teletext program is about 1 Kbyte, the compression rate is not good even if compressed in "page" units. In the case of a program unit, the compression rate is improved because the average is about 10 Kbytes.

(Sixth Embodiment) The sixth embodiment of the present invention will be described below with reference to FIGS. Figure 1
0 is an overall system configuration diagram in the sixth embodiment,
1 to 13 are similar to the configuration of FIG. 9 is different from FIG. 9 in that a file archive unit 14 that collects files managed by the file management unit 8 is added. The operation will be described below.

FIG. 11 shows that a plurality of files according to the present embodiment are collectively compressed into an archive compressed file,
In addition, it is a diagram for explaining an operation of decompressing a predetermined file from an archive compressed file.

When the storage of the predetermined page files of the received teletext data is completed, the file archive section 14 puts the page files together.

The archiving method at this time is summarized when five files are arranged in order from the page file having the smallest page number. The number of files to be collected is 5 files in consideration of the average number of pages of teletext programs (about 10 pages), the processing time at the time of compression, and the like. The number of files may be set for each teletext program.

For example, when the teletext program consists of 8 pages, the file archive section 14 has 1 to 5 pages and 6 pages.
~ 8 pages are combined into one file.

A case where the archive file is compressed will be described with reference to FIGS. 11 (a) and 11 (b).

In FIG. 11A, when the teletext program is composed of 3 pages, the file archive section 14 collects 1 to 3 pages. At this time, the file archive unit 14
The total number of files and file names (for example, the page number name is the page file name) and the size of each expanded file are written in the compressed file / file conversion table 14a. And the archive file is
It is stored as an archive compression file by the data compression unit 12.

FIG. 11B shows a case where each file has a compressed file / file conversion table 14a in the archive compressed file. In this case, the data compression unit 12 writes the compressed file / file conversion table 14b into the archive compressed file when the compression of the archive file is started.

The files are collectively compressed by the property of the LZ compression algorithm, as described in the fifth embodiment. That is, since the average length of each "page" of the teletext program is about 1 Kbyte, if the file unit is "page", the compression rate is not good even if only one file is compressed. By compressing collectively, the compression rate in the LZ method is improved as compared with the case of "page" unit.

Next, the case of decompressing a predetermined file from an archive compressed file will be described with reference to FIG. FIG. 11C is a diagram when only the third page file is decompressed from the archive compressed file described in FIG. 11B.

Compressed file / file conversion table 14
b is used to decompress only a specific compressed file in the archive compressed file. The data decompression unit 13
Due to the nature of the LZ compression algorithm, decompression can be performed only from the beginning of the file.

Therefore, when decompressing a specific file, decompression is performed while comparing the size of each data in the compressed file / file conversion table 14b with the sequentially decompressed data size, and the decompressed data of only the specific file is held. The decompressed data other than is discarded.

When only a specific file being compiled is needed, it is not necessary to decompress other files on the memory.

As described above, the compression ratio is increased by collectively compressing / expanding the files in "page" units. Further, it becomes easier to change the page data for each "page" in accordance with the update of the teletext as compared with the file for each program.

By devising the compressed file name, the file name in the archive compressed file need not be stored in the compressed file / file conversion table.

For example, in the case of grouping teletext programs in order from the file with the smallest page number, a file obtained by archive-compressing pages 1 to 5 as shown in FIG. 11 (d) is "05.Z", and pages 6-8. The file that is archive-compressed is "08.Z". At this time, the maximum number of files to be collected is 5. The compressed file / file conversion tables 14c and d in the respective archive compressed files store the number of files summarized at the beginning and the file size from a small page, so that the file size of any page can be stored without storing the file name. I understand. In the case of "08.Z", it is understood from the file name that pages 6 to 8 are stored in this summary. Then, similarly to "05.Z", the size of the page file corresponding to the page can be known.

(Seventh Embodiment) The seventh embodiment of the present invention will be described below with reference to FIGS. In the present embodiment, file management when the file management unit 8 of the first to sixth embodiments has a directory structure will be described. In this case, the file unit is "page" of the teletext program.

FIG. 12B is an explanatory diagram when the file management unit has a directory structure. A channel directory layer is provided in the root directory. When the number of channels is 6, there are 6 channel directories. A program directory layer is provided in each channel directory. When the number of programs is 50, there are 50 program directories. Further, a page file is created in each program directory.

Also, in the program directory, an archive compression file in which page files are collected by the file archive section 14 of FIG. 10 and compressed by the data compression section 12 is also stored.

FIG. 12A shows file management when the directory structure is not included. If you do not have a directory structure, all files will exist in the root directory. For example, the number of teletext channels is 6, each channel has 50 programs,
If each program consists of 10 pages,
There are 6 × 50 × 10 = 3000 files. Searching for a single file from these files takes a considerable amount of time, and file management becomes complicated.

As described above, each page file has a three-layer directory structure including a root directory, a channel directory, and a program directory, so that the page file search, that is, the search for designating the channel, program number, and page number, can be speeded up. This makes it easier to manage files.

Further, by having a directory structure, when deleting a file managed by the file management unit 8 when the memory is full, etc., one or more files in each program directory are left, You can easily delete other files.

In the case of FIG. 12B, page [2] of program [1] on channel [1], channel [n].
Deleted from page [5] of program [4].

As a result, there is a high possibility that each program directory will have more than one page file, and the program desired by the user can be searched and displayed for at least one page without waiting time.

(Embodiment 8) Hereinafter, Embodiment 8 of the present invention will be described with reference to FIGS. In the present embodiment, file access in the file management unit 8 and the archive file management unit 14 when reading and writing a file on the multitask OS in the system of FIG. 10 will be described.

In FIG. 13, reference numeral 131 denotes a storage task for storing the text broadcast data obtained through the text broadcast program selection section 4 by the file management section 8 to create a page file and store the data, and update the data. Reference numeral 132 denotes a compression task that archives a file in the file archive unit 14 and then compresses the file to create an archive compression file. 133 is a decompression task that decompresses one or more files from the archive compression file. This is a retrieval task for retrieving a predetermined file from the stored files and expanding it in the display memory 9 via the decoding unit 5.

Similar to the data compression unit 12 of the sixth embodiment,
When the accumulation tasks have completed the accumulation of the page files 1 to 5, the accumulation task requests the compression task 132 to collectively compress the page files 1 to 5.

Compression task 1 requested by storage task 131
32 collectively compresses the page files 1 to 5 to create an archive compression file. At this time, either the accumulation task or the compression task may be put together using the file archive unit 14. The compression task deletes the page files 1 to 5 upon completion of the compression. The time required for compression is about 0.5 seconds (according to the actual measurement by the CPU of 4 MIPS).

In the teletext, page data of the same program is transmitted page by page in about 20 seconds.

Due to this property, the storing task does not need to write the page file while the compressing task reads the page file and creates the compressed file, which facilitates file control.

When displaying a teletext on a television monitor,
The search task 134 file searches the decompressed file managed by the management unit 8. If the decompressed file does not exist, the archive compressed file is searched. If it exists as an archive compressed file, the file is decompressed by the decompression task 133 and read as a page file. Then, the data is written in the display memory via the decoding unit 5.

Next, when a page update occurs, first,
The accumulation task 131 searches the decompressed page file. If the file does not exist, a new page file is created and page data is stored. At this time, a new page file is created even if the archive compressed file exists. If the decompressed page file exists, overwrite it.

When displaying a teletext on a television monitor,
As described above, the search task requests the decompression task 133 to decompress data and decompresses the page file from the archive compression file. However, a case where the same page file is updated while decompressing the page file will be described. To do.

In this case, the storage task 131 forcibly deletes the page file whose data is being expanded and creates a new updated page file. Since the decompression task 133 cannot write data to the file, the retrieval task 134 of the request source
Notify the extension error. When the search task 134 is notified of an error from the decompression task 133, the search task 134 waits for the completion of accumulation of the update data file and then extracts the data from the file.

As described above, by using the above-mentioned file access control, the processing in the case where the simultaneous writing from a plurality of tasks or the writing to the file being read occurs for one file on the multitask OS Can be done.

As a result, it is not necessary to create a temporary file for file editing for file access control, so that the memory capacity for accumulating teletext data is not reduced.

[0093]

As described above, according to the present invention, file access can be made flexible, and a compressed file can be freely created and a decompressed file can be deleted. Moreover, since the efficiency of use of the memory is significantly improved, it is possible to provide an inexpensive teletext receiver and its method with about 70% of the conventional memory.

[Brief description of drawings]

FIG. 1 is a block diagram showing an overall configuration of a teletext receiving device according to a first embodiment of the present invention.

FIG. 2 is a memory configuration diagram showing a data storage state of a data storage unit according to the first embodiment of the present invention.

FIG. 3 is a memory configuration diagram showing a data storage procedure in a data storage unit according to the first embodiment of the present invention.

FIG. 4 is a block diagram showing an overall configuration of a teletext receiving device according to a second embodiment of the present invention.

FIG. 5 is a memory configuration diagram showing a data storage state of a data storage unit according to the second embodiment of the present invention.

FIG. 6 is a memory configuration diagram showing a data storage state of a data storage unit according to the second embodiment of the present invention.

FIG. 7 is a memory configuration diagram showing a data storage procedure in a data storage unit according to the third embodiment of the present invention.

FIG. 8 is a memory configuration diagram showing a data storage procedure in a data storage unit according to the fourth embodiment of the present invention.

FIG. 9 is a block diagram showing an overall configuration of a teletext receiving device according to a fifth embodiment of the present invention.

FIG. 10 is a block diagram showing an overall configuration of a teletext receiving device according to Embodiments 6, 7, and 8 of the present invention.

FIG. 11 is a block diagram showing archive file management according to the sixth embodiment of the present invention.

FIG. 12 is a block diagram showing a directory layer in file management according to a seventh embodiment of the present invention.

FIG. 13 is a block diagram showing a software configuration of a teletext receiving device according to an eighth embodiment of the present invention.

FIG. 14 is an overall configuration diagram of an example of a conventional teletext receiver.

FIG. 15 is a configuration diagram of a data storage unit of a conventional teletext receiver.

FIG. 16 is a data format diagram of a conventional teletext receiver.

FIG. 17 is a configuration diagram of a data storage unit of a conventional teletext receiver.

[Explanation of symbols]

1 CPU 2 memory 3 character signal extraction part 4 Teletext program selection section 5 Decoding section 6 Data storage 7 Memory management unit 8 File management department 9 Display memory 10 Display control unit 11 TV monitor

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hirotoshi Uehara             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. (72) Inventor Keiya Miyoshi             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. F term (reference) 5C053 FA20 GA11 GB05 GB21 HA29                       JA16 JA21 KA24 LA06                 5C063 AB03 AC10 DA03 DA13 EB27                       EB50                 5K061 BB07 JJ06 JJ07

Claims (4)

[Claims] 1. A signal extraction means for receiving broadcast radio waves and extracting teletext data, and a teletext program selection means for selecting teletext data of at least one teletext program from the extracted teletext data. A data storage unit for storing the selected teletext data, a file management unit for managing a page of the teletext data as one file, and a data compression unit for compressing the file to create a compressed file. A data decompression means for decompressing the compressed file to create a decompressed file, and a plurality of page files included in one program managed by the file management means for each predetermined number of files based on the compression processing time. A file archive means for collectively creating an archive file is provided. A broadcast receiving apparatus, wherein the archive file is compressed by the data compression means. 2. The file archive means has a management table for managing the start position information of each file in the compressed file obtained by compressing the archive file and associating the compressed file with the uncompressed file. 1. The broadcast receiving device according to 1. 3. When the data compression unit compresses an archive file, a management table that associates the compressed file with an uncompressed file and compressed data of the archive file are accumulated and managed as one file. The broadcast receiving device according to claim 1. 4. The data decompressing unit specifies at least a compressed file obtained by compressing an archive file by using a management table existing in the file archiving unit or in the compressed file and associating the compressed file with the uncompressed file. The broadcast receiving apparatus according to claim 2 or 3, wherein one file is decompressed.