JPH01320883A - Teletext receiver - Google Patents

Abstract

PURPOSE:To quickly retrieve a program by performing the same operation based on certain key information at the time of recording and calling character broadcast program data in and from a data memory and avoiding collision in accordance with the same procedures at the time of detecting collision. CONSTITUTION:The program number is discriminated from received character broadcast data and is inputted to an arithmetic unit 28. The unit 28 subjects the program number to prescribed operation to obtain a subsection number. A subsection selector 30 stores character broadcast reception data in a data storage area for the subsection in a data memory 16 in accordance with this subsection number and stores management information in a management information area for the subsection. When program data stored in the data memory 16 is read out, an arithmetic unit 32 subjects the program number to the same prescribed operation as the arithmetic unit 28 to obtain the subsection number of the data memory 16. Number data in the data storage area for the subsection selected by a subsection selector 34 is supplied to a data processing part.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a teletext receiving device, and particularly to a teletext receiving device having a large capacity data memory for storing received program data.

[Prior Art] In a teletext system, a teletext signal is transmitted in a data packet format, with a unit length of data superimposed on one horizontal scanning period within a vertical blanking period of a television signal. On the sending side, with this transmission format,
Since a large number of programs are transmitted periodically, when a receiver selects a specific program, there is a waiting time until that program is received and displayed.

Therefore, as a countermeasure against this waiting time, a teletext receiving apparatus has been developed that sequentially captures received data into a large-capacity data memory so that the program data can be displayed immediately after the viewer selects a program.

A block diagram of a conventional example of this teletext receiving apparatus is shown in FIG.

A multiplexed video signal in which a teletext signal is multiplexed during a vertical blanking period is input to a teletext signal extraction section 10, and only the teletext signal portion (program data) is extracted. This extracted teletext signal is manually input to the data importing section 12. This data importing unit 12 performs error detection, error correction, etc. of program data, and a central processing unit (CPU) 14
, the necessary program data is stored in the data memory 16.
to be memorized.

On the other hand, key human power signals (key coats) generated by key operations by viewers to select programs, make program reservations, etc.
The operation and control section is manually operated on a daily basis.

This operation control unit 18 decodes the input key code. Then, based on the judgment of the CPU 14, the data import unit 12 performs program acquisition and reservation selection, and searches for necessary data stored in the data memory 16.

The data processing unit 20 decrypts the retrieved data,
The imaged data is transferred to frame memory 22. The display control unit 24 reads data from the frame memory 22 at a predetermined timing and displays information on the selected program on the display unit 26.

In such conventional teletext receiving apparatuses, the following three methods have been proposed for accessing the large capacity data memory.

(1) In the first method, program data of an input teletext signal is sequentially stored in a large-capacity data memory. If there is a teletext program selected by the viewer in the stored program data, that teletext program is immediately displayed. Furthermore, if there is no teletext program selected by the viewer in the stored program data, the system waits for the next teletext signal.

(2) In the second method, the viewer knows in advance the program number of the desired teletext broadcast and reserves that program number by operating keys or the like. Further, the large-capacity data memory is divided into a plurality of small sections, with the maximum amount of data for one transmission unit being one storage unit. Therefore, it is possible to store as many reserved teletext programs as there are divided small sections.

(3) In the third method, the data memory is divided into a plurality of small sections in units of data amount equivalent to the smallest program. For programs with a large amount of data, use multiple small sections.
Store data. That is, reserved program data is preferentially stored in one or more small sections of the large-capacity data memory, and program data that is not reserved but to be received sequentially is stored in the remaining area. . A management data area is provided for each small section, and this includes information such as whether it is a reserved program, the program number of the stored data, and connection information when using multiple small sections. It is recorded. When storing program data, management data for each subdivision is sequentially checked to find a subdivision in which the received data can be stored. Similarly, when selecting a program, the management data for each subdivision is sequentially searched for the corresponding program number, and the necessary program data is found from the data memory.

[Problems to be Solved by the Invention] By the way, in the first method described above, when new program data arrives and this data is stored, old data is sequentially erased. Therefore, necessary program data cannot be stored in the data memory for a long period of time. Furthermore, when a program is selected and the data memory is searched, the search must be performed for each data packet, which takes time.

In the second method, in order to store one program, it is necessary to prepare a data memory that can store the maximum amount of data for one program. On the other hand, since the amount of data varies depending on the program, in the case of a program with a small amount of data, the unused area in the data memory increases, which is uneconomical.

The third method improves the shortcomings of the first and second methods, but when storing data in each small partition or recalling data from each small partition, management data for each partition is You must perform a sequential comparison search starting from the beginning. Wait,
Assuming that the selected program is stored and there are n small sections, an average of 11/2 comparison searches is required, which increases the search time.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a teletext receiving apparatus that can effectively use a large-capacity data memory, store program data at high speed, and search stored program data at high speed.

[Means for Solving the Problems] The teletext receiving device of the present invention extracts the teletext signal time-division multiplexed during the vertical blanking period from the received multiplexed television video signal, performs error correction processing, It is a device that performs decoding processing, display processing, etc., and displays the program content of teletext broadcasting on a display unit, and has a large-capacity data memory for storing and accumulating program data related to teletext broadcasting. It has a function that allows you to reserve and register programs to be stored in advance.The data memory is divided into multiple small areas, each of these small areas is numbered, and when data is stored, key information such as program number is stored. A predetermined calculation is performed on the data, and a small section of the large-capacity data memory is selected according to the calculation result to store the program data. Also, when retrieving the necessary program data, the specified program number, etc. It is characterized in that a predetermined calculation is performed on the key information, and a subdivision in which necessary program data is stored is called up according to the calculation result.

[Operation] Normally, screen selection for teletext broadcasting is performed by program number. If it is possible to determine from this program number information in which small section in the large-capacity data memory the data of the corresponding program is stored, or whether there is a high probability that the data is stored,
High-speed search is possible.

The present invention identifies a program number and performs certain operations on the program number when storing received data in a data memory. Based on this calculation result, a small area to be stored is determined and the corresponding data is stored. Further, when calling up necessary program data, the same calculation as when storing is performed on the program number, and a small section in which the necessary program data is stored is quickly searched.

[Embodiments] Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a block diagram showing the concept of main parts of a teletext receiving apparatus according to the present invention. This block diagram is based on the CP in Figure 4.
The relationship between U14 and mass data memory 16 is replaced, and the other blocks are the same as in FIG.

In the present invention, the CPU 14 includes the arithmetic units 28 and 32,
Conceptually, the subdivision selection devices 30 and 34 are included.

However, these blocks within the CPU 14 are
Note that this does not indicate that the inside of U is like this.

In the following description, in order to facilitate understanding, the conceptual configuration shown in FIG. 1 will be used. The connection relationship between each block in FIG. 1 and FIG. 4 is as follows.

That is, the arithmetic device 28 receives the program number from the data importing section 12. The small section selection device 30 receives the output of the arithmetic device 28, the reserved program information (key human power) from the operation control section 18, and the reception (program) from the data import section 12.
It receives data and provides its output to mass data memory 16.

On the other hand, the arithmetic device 32 receives the program number (key input) from the operation control section 18. The subdivision selection device 34 receives the output of the arithmetic device 32 and the program data in the data memory 16, and supplies the output to the data processing section 20. Note that the operation of each block in FIG. 1 will be described later.

FIG. 2 shows how the large capacity data memory 16 is divided into (n+1) small sections of equal size IO-. That is, the data memory 16 stores subdivision numbers 0 to 0.
It is divided into subdivisions 0-n labeled n.

FIG. 3 is a diagram showing the storage area of each small section of the data memory 16. As shown in this figure, each small section is composed of a data storage area for storing program data and a management information area for storing management information. Note that the management information includes the usage status of the corresponding small section, information as to whether it is a reserved program, connection information of small sections when one program is stored using a plurality of small sections, and the like.

Referring again to FIG. 1, the operation of the embodiment of the present invention will be described.

When storing program data in the data memory 16, the program number is determined from the received teletext data and input into the arithmetic unit 2. This arithmetic unit 28 performs some kind of predetermined arithmetic operation on the program number to obtain the subdivision number.

The parcel selection device 30 selects a parcel in the data memory 16 according to the parcel number determined by the arithmetic device 28. Then, teletext reception data (program data) is stored in the data storage area of the selected small section, and management information is stored in the management information area of the selected small section.

Note that the reserved program information from the operation control unit 18 becomes part of the management information. Further, other management information (usage information, connection information, etc.) is generated by the small section selection device 30.

The parcel selection device 30 checks the management information area of the selected parcel when storing data in the data memory 16. If received data of another reserved program is already stored in the selected subdivision (if a collision is detected), the arithmetic unit 28 uses a certain procedure to store the received data next. Select the parcel you want. If the received data of another reserved program is stored in that small section, the same procedure is used to search for small sections that can store the received data one after another.

When storing data in the data memory 16, reserved programs have priority, and a small section in which a reserved program is stored will not be rewritten with anything other than update data of the same program number. However, in a small section where unreserved programs are stored, new data is rewritten even when a collision is detected.

On the other hand, when reading program data stored in the data memory 16, the program number is specified using an external key or the like. Arithmetic device 32 performs the same predetermined calculation as arithmetic device 28 on this program number to obtain the subdivision number of data memory 16.

The subdivision arithmetic unit 34 checks the management information area of the corresponding subdivision in the data memory 16 according to the subdivision number obtained by the arithmetic unit 32, and when a collision is detected, performs processing such as collision detection in the same way as when storing. is performed together with the arithmetic unit 32.

In this way, the data that stores the necessary data
A small section of the memory 16 is immediately found, the program data in the data storage area of the small section is read out, and is supplied to the data processing section 20.

The calculation and collision detection processing methods of the calculation units 28 and 32 are as follows:
Taking into consideration the bias in program numbers of current teletext services, if the program numbers are manually generated, the output after calculation will be scattered appropriately. Care must be taken to select the following parcels in sequence.

Although the preferred embodiments of the present invention have been described above, various modifications and changes can be made without departing from the gist of the present invention. For example, in the embodiment, the CPU performs processing such as calculations and collision detection, but each block within the CPU shown in FIG. 1 may be configured as an individual circuit. Further, in the embodiment, the program number is used as the key information, but a magazine number, page number, etc. may be added to the program number.

[Effects of the Invention] As described above, the present invention performs the same operation on the data memory based on certain key information (program information) when storing and recalling teletext program data, and also avoids conflicts. At the time of detection, the same procedure is used to avoid collision.

Therefore, the entire data memory divided into small sections can be effectively utilized and calls can be made immediately.

Furthermore, program data can be effectively stored even for non-discarded programs for which the maximum amount of data is not specified, such as programs that span many pages.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the concept of the main part of a preferred embodiment of the present invention, FIG. 2 is a diagram showing the division state inside the data memory, and FIG. 3 is a diagram showing the storage of small sections in the data memory. FIG. 4, a diagram showing the contents, is a block diagram of a conventional example. 10... Teletext signal extraction unit 12... Data import unit 14... CPU 16... Data memory 18... Operation control unit 20... Data processing unit 22... Frame memory 24 ... Display control section 26 ... Display section 28.32 ... Arithmetic device 30.34 ... Small section selection device Patent applicant Sharp Corporation

Claims (1)

[Claims] From the received multiplexed television video signal, the teletext signal that has been time-division multiplexed during the vertical blanking period is extracted, and subjected to error correction processing, decoding processing, display processing, etc., to produce a teletext signal. A teletext receiving circuit that displays program contents on a display unit, which has a large-capacity data memory for storing and accumulating program data related to the teletext, and is capable of pre-registering programs to be stored in the data memory. In a teletext receiving device that has the function of performs calculations, selects a small section of the large-capacity data memory according to the calculation results, stores the program data, and retrieves key information such as the specified program number when retrieving the necessary program data; A teletext receiving apparatus characterized in that the predetermined calculation is performed on the data, and the subdivision in which the necessary program data is stored is called in accordance with the calculation result.