JPH0423997B2 - - Google Patents

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, and in particular to a display memory for writing data of generated character/graphic patterns. The present invention relates to a teletext receiving device that improves the allocation of attribute memory for writing data for controlling concealment, etc., so that screen display becomes smooth (natural).

(Prior Art) Recently, teletext broadcasting (hereinafter referred to as teletext) has been put into practical use as a new broadcasting service.
Furthermore, compared to the conventional pattern method, there is a hybrid method that combines the advantages of the pattern method with a code method having good (high) transmission efficiency.

Unlike regular television programs that are organized by time, teletext repeatedly transmits a variety of information and entertainment programs consisting of text, graphics, and additional sounds, allowing viewers to access the information they want when they want it. This is a new broadcasting system that has made it possible to

The information such as the above characters and figures is multiplexed with the television radio waves (video signals) from the currently broadcasting station and is broadcast, and the recipient must prepare a receiving broadcast or an adapter that can receive text broadcasting. Then, the desired teletext program can be viewed from among many teletext programs.

Furthermore, this teletext signal (text signal packet) is transmitted as a digital signal using the time gap (that is, the vertical blanking period) of the current television signal, and the receiving device side receives the signal. It is decoded and converted into a television signal, which displays images on the television screen and emits additional sounds such as music, so that text programs can be viewed.

The above-mentioned receiving device and adapter are composed of a character decoder, and an example of the configuration of this character decoder is shown in FIG.

In the figure, a character decoder separates and extracts a character signal from a demodulated video signal (television signal) supplied via input terminal 1, decodes the character data, and displays and adds it to the screen in various display formats. It is used to reproduce sound. and,
These signal processes are performed by a microprocessor (CPU).
10.

The synchronization separation circuit 2 generates gate pulses to separate character signals, and also generates timing signals to reproduce byte synchronization signals and clock signals used as bit synchronization necessary to reliably extract specified data packets. Each signal is then supplied to a waveform equalization circuit 3, a character signal separation circuit 4, and a display clock generation circuit 12, respectively.

The waveform equalization circuit 3 compensates for waveform distortion caused by ghosts and the intermediate frequency amplification circuit of the receiver.

The character signal separation circuit 4 separates the character signal from the video signal using the gate pulse generated by the synchronization separation circuit 2, performs code identification at the timing of the clock signal, and extracts digital data of "1" and "0". It is.

The error correction circuit 5 corrects code errors occurring during signal transmission, and for this error correction, for example, a method capable of correcting errors of up to 8 bits in one data packet is adopted.

The character data whose errors have been corrected in this way is taken into the buffer RAM 6 via the bus line and decoded. And this decryption procedure is the program
Processing is performed according to the decoding processing procedure written in the ROM 7.

Further, generation of characters and figures is performed by accessing a character generator (character and figure pattern generator) 8. Note that 9 is a work ROM.

Furthermore, the generated character/graphic pattern data is written into the display memory 11 and read out in synchronization with the horizontal and vertical scanning cycles. The read pattern data is then sent to the color matrix circuit 14.
The signals are converted into analog R, G, and B signals, applied to a picture tube (not shown), and displayed on a screen. Note that 13 is a display control/bus control circuit.

The above display memory 11 is a pattern memory 11
a and an attribute memory 11b. The pattern memory 11a is for writing shape data such as character shape patterns and various mosaic patterns. The attribute memory 11b is used to write data regarding display attributes such as foreground and background coloring, flashing, and concealment.
The unit for controlling this display attribute is called a functional block, and its size can be specified as a section four times the length and width (4 dots x 4 lines) of the smallest logical pixel (dot).

That is, as shown in Fig. 3a, the minimum unit 20 of the functional block is 4 dots x 4 lines, which in turn becomes 4 bits x 1 as shown in Fig. 3b.
It is allocated and written into the attribute memory 21 for lines.

(Problem to be solved by the invention) However, as mentioned above, the allocation of the attribute memory 21 is limited to the minimum unit of 20 (4 dots x 4
When the attributes of the block are set, 4 dots x 4 lines are colored all at once, resulting in an unnatural display during the writing operation on the screen.

That is, as shown in Figure 3c, 4 dots x
When writing 4 dots x 4 lines to the attribute memory 21 after writing to the pattern memory 22 for 4 lines, writing to the attribute memory 21 ends after writing to the pattern memory 22 ends. Until then, the display is performed based on the previous content (data) that has already been written to the attribute memory 21, so the display is momentarily colored in an unnatural color, making the display unnatural. .

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a teletext receiving device that can solve the above-mentioned problems of the conventional technology and make the display smooth (natural) during the writing operation on the screen. do.

(Means for Solving the Problems) In order to achieve the above object, the present invention receives a character signal superimposed within a vertical blanking period of a television signal, and stores data of this character signal in a pattern memory. In a teletext receiving device that performs display by writing to a display memory consisting of an attribute memory and an attribute memory, data of a functional block consisting of multiple lines is written by allocating an attribute memory for each line. The present invention provides a teletext receiving device characterized in that it is configured as follows.

(Function) In the teletext receiver having the above configuration,
After one line of data is written into the pattern memory, one line of data is written into the attribute memory corresponding to that line, and this is performed alternately.

(Embodiment) An embodiment of the teletext receiving device according to the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing the configuration of a display memory which is a main part of an embodiment of a teletext receiving apparatus according to the present invention.

As shown in Figure 1a, the minimum unit 30 of the functional block consisting of 4 dots x 4 lines is further
Divide each line into four lines (4 dots x 1 line). Also, as shown in Figure 1b,
The attribute memory 31 is composed of four attribute memories of 4 dots x 1 line (first to fourth attribute memories).

Then, as mentioned above, the minimum unit of the functional block
30 is divided into 4 parts, and the data for 4 dots x 1 line is allocated and written to each of the 4 attribute memories (1st to 4th attribute memories) of 4 dots x 1 line for each line. Do it like this.

Further, the above-mentioned attribute memory 31 includes a foreground color memory, a background color memory, a flushing memory, etc., and data is allocated and written to each of them as described above.

Furthermore, when writing data to the attribute memory 31 and pattern memory, one line of pattern data was written to the first pattern memory of the pattern memories 32 as shown in FIG. 1c. After that, one line of attribute data is written in the first attribute memory of the attribute memory 31, then one line of pattern data is written in the second pattern memory, and then the second attribute data is written in the same manner. Write one line of attribute data to memory.

Then, below, 1 to the third pattern memory
Writing pattern data for a line → Writing attribute data for one line to the third attribute memory →
Writing is performed in the order of writing one line of pattern data to the fourth pattern memory→writing one line of attribute data to the fourth attribute memory.

By writing in this manner, writing on the screen is performed smoothly (naturally) from top to bottom (or from bottom to top).

As described above, the attribute memory (foreground color memory, background color memory, flushing memory, etc.) corresponding to 4 dots x 1 line is allocated to each line, and display pattern data is stored in the pattern memory.
By alternately writing data for each line into the attribute memory for each line, the screen can be displayed smoothly (naturally).

(Effects of the Invention) As described above, according to the teletext receiving device of the present invention, the screen display can be made smooth (natural) from top to bottom (or from bottom to top). It has characteristics.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a configuration related to a display memory which is a main part of an embodiment of a teletext receiver according to the present invention, FIG. 2 is a diagram showing an example of the configuration of a character decoder, and FIG. FIG. 2 is a diagram showing a configuration related to a display memory of a broadcast receiving device. 11...Display memory, 11a, 32...Pattern memory, 11b, 31...Attribute memory, 30...
...Minimum unit of functional block, ,,,...
First to fourth pattern memories,,,,...
...first to fourth attribute memories.

Claims (1)

[Claims] 1. A character signal superimposed within a vertical blanking period of a television signal is received, and the data of this character signal is written to a display memory composed of a pattern memory and an attribute memory to be displayed. 1. A teletext receiving device characterized in that the teletext receiving device is configured such that data of a functional block consisting of a plurality of lines is written by allocating an attribute memory for each line.