JPS6182591A - Teletext receiving device - Google Patents

Abstract

PURPOSE:To prevent the interruption of a picture display by comparing data contents of two character signals stored in a memory means, retaining display data in picture memory as it is when they are equal and keeping on displaying a picture being displayed currently as it is. CONSTITUTION:A control part 12 discriminates in units of data packet whether of not input data is the same program data as the program which is selected by a user. When they are equal, the control part 12 stores them in a character data storage memory 13 by data packet. Thus data of one screen is stored in the character data storage memory 13. The control part 12 transfers the character data stored in said memory 13 and character data stored in a character data fetching memory 18 to data comparison part 19. When the result that contents of both data are equal is obtained from the data comparison part 19, a picture display continues with display data having stored in a picture memory 14.

Description

[Detailed description of the invention] [Technical field of invention] The present invention relates to a teletext broadcasting receiving apparatus.

[Technical background of the invention]

In teletext broadcasting, the text signal is TV-)! It is superimposed on the vertical blanking period of the main broadcast signal. Specifically, if the superimposition period is the first field, it is assigned to the horizontal scanning period of the 10Ith (161st to 161st horizontal scanning period) and the 21st H horizontal scanning period of the horizontal scanning number.
27th, if it is yield, the horizontal scanning number 273R
Horizontal scanning period from the 279th H to the 284th H
The horizontal scanning period of the eye K @D is applied.

Also, the character signal may be superimposed on a plurality of horizontal scanning periods in the above-mentioned superimposition period, or may be superimposed on one horizontal scanning period.

Furthermore, one teletext program (hereinafter simply referred to as a program) is time-divisionally superimposed on a field-by-field basis in units of data/4 digits during a specific horizontal scanning period of the above-mentioned horizontal scanning period. .

However, during this horizontal scanning period, r of the character signal of the same program
- Tanonkets are not always superimposed consecutively for each field, and in many cases, data of character signals of a plurality of programs are mixed and superimposed in each field. In other words, the character signal data of a plurality of programs are repeatedly sent in a predetermined order.

Each program consists of one page or pages.

Furthermore, each page may consist of character signals for one screen with the same image content, or it may consist of character signals for multiple sides of different image content.

In a teletext receiving device, data of a character signal of a program selected by a user from a television signal (hereinafter referred to as a teletext signal) in which character signals of a plurality of programs as described above are superimposed is received. is captured in one screen, its contents are decoded, the display data is stored in the image memory, and the image of the program is displayed. Then, the next time a character signal for the same program is sent, the display data in the image memory is rewritten accordingly, and an image is displayed in accordance with the newly sent character signal.

[Problems with background technology]

However, the conventional teletext receiving apparatus has the following problems. In other words, in a conventional teletext receiving device, when a new character signal/signal for one screen with the same program number is sent from the transmitting side, the image display is automatically interrupted and the display data in the image memory is rewritten. It is designed to do this. Here, the character signals for one screen repeatedly sent from the sending side do not always have different image contents, for example, when one page consists of character signals for one screen with the same image content. Not necessarily. In the conventional teletext receiving device, 1. Even in such a case, since the display data in the image memory is rewritten, there is a problem in that image display is temporarily interrupted even though the image content is the same.

From the user's point of view, the image display is interrupted and when they expect a new image to be displayed, the same image is displayed again, which makes them feel strange and uncomfortable. Ta.

[Purpose of the invention]

This invention was made to deal with the above-mentioned situation, and even though the newly sent character signal for one screen has the same content as the character signal of the currently displayed image, the image display is interrupted. It is an object of the present invention to provide a teletext broadcasting receiving device that can prevent such problems from occurring.

[Summary of the invention]

This invention provides character signals for one screen of the currently displayed image;
A memory means is provided for storing character signals for one screen of newly sent images, and two characters stored in this memory means are provided.
The data contents of the two character signals are compared, and if they are the same, the display data in the image memory is changed to "K" and the currently displayed image is continued to be displayed.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a circuit diagram showing the configuration of one embodiment.

The configuration and operation of FIG. 1 will be explained below using chart 70 of FIG. 2.

In FIG. 1, a received teletext broadcasting signal is given to a character data importing section 1. The character data import unit 11 separates character signals from input signals, samples them, and converts them into digital data. This character data is given to the control section 12. The control unit 12 determines whether the input data is data of the same program as the program selected by the user in units of 1,000 data units, and if they are the same, the control unit 12 stores the input data in the character data storage memory 13 in units of data packets. Store in . In this way, the character data storage memory 13 stores 1
Data for the screen is stored.

The control unit 12 decodes the data stored in the character data storage memory 12, obtains display data according to the decoding result, and stores this in the image memory 14. The display output circuit 15 obtains a video signal according to the display data stored in the image memory 14, and uses this video signal to output the cathode ray tube 16.
to drive. As a result, the image of the program selected by the user is displayed. Note that the designation data of the program selected by the user is provided to the control unit 12'VC from the key operation input unit 17 by the user's key operation, for example.

The character data of the same program after one screen of character data imported into the character data storage memory 13 is then written into the character data acquisition memory 18 by the control section 12, as shown in step S1 in FIG. . This memory 18
Character data is also written for one screen in units of two kerats.

Control unit z:zld-1 At step fS2 in FIG. Transfer and compare both data. Then, when the comparison result is obtained from the data comparison unit 19 that the contents of both data are the same, Stella f
S.

Then, the image display based on the display data already stored in the image memory 14 is continued. tb, both memory 1
3. If the contents of the character data stored in the IIJ are the same, the newly received character data stored in the memory 18 is decoded and the image memory 1 is decoded according to the decoding result.
Image memory 1 is saved without rewriting the display data of 4.
The contents of step 4 remain as they are, and the currently displayed image continues to be displayed. This prevents the image display from being temporarily interrupted even though character data with the same content has been received, and prevents the user from feeling uncomfortable due to viewing an image with the same content again after the image display is interrupted. I can do it.

On the other hand, Step S! When a comparison result is obtained that the contents of the data from both universities are different, the control oil 12 displays a message (or outputs a voice) on Stella 7's4 to prompt the user to update the display image. to the user.

Changes to the display image within each section or changes to the display image due to page changes, or even changes to the display image due to changes in the content of the same program, will not be processed immediately. , the display data in the image memory 14 is not rewritten, and the user is asked if it is okay to switch the displayed image.

After outputting this message, the program moves to Stella fSs and monitors instructions 2 to 5 regarding updating of the display image. This instruction data is input to the key operation input section 1 according to the user's key operations.
7 to the control unit 12. Here, if there is an instruction to prohibit updating of the display image, the system moves to the Stella fS3, leaves the display data in the image memory 14 as is, and continues to display the image currently being displayed. On the other hand, if there is an instruction to allow updating of the display image or if there is no instruction within a certain period of time, the control unit 12
Then, the character data stored in the character data import memory 18 is transferred to the character data storage memory 13.

Thereafter, in step Sγ, the control unit 2 decodes the character data in the memory 3 and rewrites the display data in the image memory 14 according to the decoding result. As a result, the displayed image is updated to a different image with the newly received content.

Here, the data comparison operation of the data comparison section 19 will be explained. As shown in FIG. 3, the character signal data packet is divided into a clock run-in signal section CR and a framing code section FC.
, a glyph section PFX, an information raster section, and a check code section.

In the character data storage memory 13 shown in FIG. 1, a plurality of pieces of data, 4 characters of character data, constituting one screen of the currently displayed image are stored in units of data packets, as shown in FIG. There is. Similarly, the newly received character data for one screen is also stored in the character data import memory 18.
As shown in the figure, data is stored in r-ta/4' ket units.

The data packets include a control data packet containing various control information and an information r-tano flat packet containing mainly image information.

FIG. 5 shows an example of the comparison operation of the data comparison section 19. First of all, the first stage is Stella fS.

In S2, it is determined whether the program number and page number of the received program match. As the second stage, step 53
At eS4, a comparison is made to see if the amount of data constituting one program (data length) and the types of data constituting one program match. As a third stage, the data content of each r-ta unit is determined in steps S, , S, or the like.

First, the contents of the page control data unit that controls one page of the program are compared and determined, and then the 74 pieces of data stored in the memory 13.18 are sequentially compared.

Figure 6 shows an example of the data structure of the 4-digit control data field, where #i, program number data, and (
- This includes page number data, step number data, and packet number data used to compare the data lengths of step and step s3 (Figure 5).

In the above explanation, character data for one screen of the currently displayed image is always stored in one of the memories 13, but the data may be stored alternately in the two memories 13 and 18. . In other words, if the character data stored in memory 8 is not equal to the character data stored in memory 3, leave the 180 character data in memory as it is, and then use this memory 8 to store characters for one screen of the current image 6. It is used as a memory to store data, and after that, newly sent character data is taken into the memo 1) 13.

Thereafter, in the same way, each time a result is obtained that the contents of the character data in both memories 13, 1 & are not equal, the memory for storing the character data currently being displayed and the memory for storing the newly sent character data are This means switching between the two.

In addition, with this Q invention, there is no need to store the character data currently being displayed and the newly sent character data in separate memories.
The address space may be stored separately in one memory.

When the control unit 12 writes data packets of a desired program to the memory 18Vc, the data packets obtained from the character data import unit are stored in the memory 18, and then it is determined whether the data packets belong to the desired program. Only the data of the desired program may be left in the memory 18.

〔Effect of the invention〕

As described above, according to the present invention, even though the newly sent character signals for one screen of images have the same content as the character signals for one screen of images currently being displayed, the image display is interrupted. It is possible to provide a teletext broadcasting receiving device that can prevent this.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing the configuration of an embodiment of the present invention, and FIG.
The figure is a flowchart for explaining the operation in Figure 1, Figure 3 is a diagram showing the structure of a data packet, Figure 4 is a diagram showing the memory Mazda, and Figure 5 is a flowchart for explaining the data comparison operation in Figure 1. , FIG. 6 is a diagram showing an example of the data structure of a control data packet. 1. Character data import section, 2. Control section,
13.14.18...Memory, 15...Display output circuit, 16...Cathode ray tube, 17...Key operation input section, 19...Data comparison section. Applicant's representative Patent attorney Takehiko Suzue Figure 2 Figure 3 Figure 4

Claims (1)

[Scope of Claims] Memory means for storing character signals for one screen of the currently displayed image and character signals for one screen of newly sent images; and the above two character signals stored in this memory means. If a comparison result is obtained from the comparison means that the contents of the two character signals are equal, the display data of the image memory that stores the display data for image display is left as is, and the current 1. A teletext broadcasting receiving device comprising display continuation means for continuing display of an image being displayed.