JP3424057B2 - Television receiver for teletext broadcasting - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a character multiplex television receiver for simultaneously displaying a video chroma signal and a character multiplex signal on a picture tube screen.

[0002]

2. Description of the Related Art FIG. 9 shows the configuration of a color data conversion circuit in a character multiplex television receiver according to the prior art. In the figure, 31 is a character multiplex signal decoder for extracting and decoding the character multiplex signal superimposed in the vertical blanking period of the input composite video signal, 61 is a memory for storing the decoded character multiplex data, Reference numeral 62 is a memory control circuit for controlling writing and reading with respect to the memory 61, 35 is a line memory for temporarily storing the character multiplexed data for one horizontal line, and 42 is the character multiplexed data read from the line memory 35 as R , G, B
Is a look-up table for converting the color data into an analog image signal D /
It is an A conversion circuit. Reference numeral 43 is a YM signal (semi-brightness color control signal) inputting bitmap data from the line memory 35.
To generate a YS signal (character multiplex signal / video / chroma signal switching signal) by inputting bit map data to the switch 26. It is a character multiplex signal / video / chroma signal switching signal generation circuit for outputting. By switching the switch with the YS signal, the video / chroma signal and the character multiplex signal are simultaneously displayed on the picture tube screen. The YM signal has a half-bright color behind the caption in the case of caption broadcasting, but in the case of character multiplexing instead of caption broadcasting, character projection is accompanied by the foreground color and background color.

[0003]

Since the characters are always accompanied by the foreground color and the background color, and the foreground color and the background color are variously changed, the projected characters themselves are difficult to see.

[0004]

According to a first aspect of the present invention, there is provided a character multiplex television receiver having a video / chroma signal processing circuit for demodulating a received composite video signal and a video / chroma signal processing circuit superimposed on the composite video signal. a teletext signal receiving circuit for taking out the teletext signals are, switch for displaying the video chroma signal and the teletext signal receiving circuit simultaneously teletext signal on the picture tube screen from from the video chroma signal processing circuit And the character multiplex signal reception
The signal circuit has a character multiplex signal for decoding the character multiplex signal.
Foreground color from decoder and decoded character multiplex data
And the background color is generated, and the foreground color is fixed before the color type is fixed.
Converts color data into scenery and background color into YM color
Color data conversion processing means and color data converted data
Store memory and stored bitmap for each line
Line memory and bitmap data for displaying on
Table to convert the color to RGB color data
And the RGB converted data into an analog RGB signal
D / A conversion circuit for conversion and bit from line memory
Generates a semi-bright color control signal (YM signal) from map data
The half-luminance supplied to the video / chroma signal processing unit
Color control signal generation means and bit map from line memory
Data multiplex signal / video / chroma signal switching
Signal (YS signal) is generated and supplied to the switch.
A character multiplex signal / video / chroma signal switching signal generating means is provided, and the background color around the character foreground color is set to a half-brightness state in the area where the character multiplex signal is displayed on the picture tube screen. It is characterized by being configured to project a video chroma signal in the back. Video background with letters background
As a result of lowering the brightness of the roma signal, the characters are easy to see.
In addition, the color type is fixed as the foreground color to be generated.
Generates the foreground color, which makes the text easier to see.
It In the above, the color data conversion processing means is
Character multiplex signal decoder for decoding signals, and decoding
Generates the foreground color and background color from the character multiplexed data
For landscape, color data conversion to fixed foreground color with fixed color type
And the background color had a function of converting to YM color.
However, instead of this, the color data conversion processing means is as follows.
It may be configured. That is, color data conversion processing means
Is the data from the decoded character multiplex data
Character / outside character or photo graphic is discriminated and character / outside
The foreground color of the character is fixed and the background color is YM.
Color data conversion process for photo graphics
It has a function that does not make sense. In this case, the image
Characters / External characters in the area where the multiplex character signal is displayed on the screen
Fixed the foreground color of the foreground to the background color around the foreground
To half-bright color, leaving the photographic
State and project a video chroma signal behind it
It As a result, the graphics displayed without color data conversion
The mocks become vivid. In addition, separately, the color data conversion process
The processing means may be configured as follows. That is, the color
The data conversion processing means is based on the decoded character multiplex data.
And whether the data is character / gaiji or photographic
If the character is a character / gaiji, the foreground color is fixed.
, The background color is converted to YM color, and the
In the case of a foreground color, color data conversion processing is performed for the foreground color.
If the background color is not performed, the data is
If the background color is Y), convert the background color to YM color,
A function that does not perform color data conversion processing if it is not transparent
Shall have. In this case, the character multiplex
Fixed foreground color of character / gaiji in the project area
In the color state, the background color around the foreground color is in the semi-bright state
In addition, the foreground color of the photo graphic remains the same,
The background color of the transparent color of the photo graphic is a half-brightness state
, The background color of the photo graphic that is not transparent is
And display the video chroma signal behind it.
It As a result, the transparent part of the photo graphic is semi-shined
The use of chromaticity makes the image easier to see.

In addition, since a fixed foreground color having a fixed color type is generated as the foreground color to be generated , the characters are easier to see.

According to the television receiver for character multiplex broadcasting of claims 2 , 4 , and 6 of the present invention, the fixed foreground color is white. If the characters are displayed in white, it will be easy to see.

In the television receiver for character multiplex broadcasting according to claim 7 of the present invention, the character multiplex signal receiving circuit converts the character multiplex signal into a state of being displayed in a vertically scrolling state on the lower side or the upper side of the picture tube screen. It is characterized by being configured as follows. Since characters are vertical scrolling sufficiently read the characters as the movies out region of the teletext signal small vertical width, yet bidet character background
Character vertical scrolling is easy to see because it overlooked the luminance Oh chroma signal. The effect is remarkable when the characters are white.

In the television receiver for character multiplex broadcasting according to claim 8 of the present invention, the picture tube has an aspect ratio of 16: 9. The entire wide screen can be effectively used.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a character multiplex television receiver according to the present invention will be described below in detail with reference to the drawings.

[First Embodiment] FIG. 1 is a block diagram showing a configuration of a character multiplex television receiver according to a first embodiment. In FIG. 1, 21 is an antenna, and 22 is a receiving circuit for receiving a television broadcast radio wave and extracting a baseband composite video signal. The composite video signal from the receiving circuit 22 is simultaneously processed by the video / chroma signal processing circuit 2
3. Character multiplex signal reception circuit 24 and sync separation circuit 25
Is being supplied to. The video / chroma signal processing circuit 23 is a circuit that demodulates the composite video signal and extracts the three primary color signals of R, G, B, and the character multiplex signal reception circuit 24 is superimposed in the vertical blanking period of the composite video signal. It is a circuit for taking out the character multiplex signal and converting it to R, G, B primary color signals. 26 is a video / chroma signal processing circuit 23
, A switch for switching the signal from the character multiplex signal receiving circuit 24 at a high speed, 27 is a picture tube drive circuit,
28 is a picture tube having an aspect ratio of 16: 9. The horizontal sync signal and the vertical sync signal separated by the sync separation circuit 25 are supplied to a horizontal deflection circuit 29 and a vertical deflection circuit 30, respectively. Character multiplex signal receiving circuit 2
4 to the switch 26, a YS signal (character multiplex signal / character multiplex signal
Video / chroma signal switching signal. This will be described later). Further, the character multiplex signal reception circuit 24 outputs a YM signal (half-luminance color control signal, which will be described later) for making the background color a half-luminance color to the video / chroma signal processing circuit 23. ing.

FIG. 2 is a block diagram showing the internal structure of the character multiplex signal receiving circuit 24. In FIG. 2, reference numeral 31 is a character multiplex signal decoder for extracting and decoding the character multiplex signal superimposed in the vertical blanking period of the input composite video signal, and 38 is color data conversion processing of the decoded character data. A color data conversion processing unit, 32 is a memory for storing the character multiplex data subjected to the color data conversion processing, 33 is a VRAM (video RAM) built in the memory 32 and writing the data to be displayed in a bitmap format, 34
Is a memory control circuit for controlling writing and reading with respect to the memory 32 and the VRAM 33, 35 is a line memory for temporarily storing character multiplex data for one horizontal line, and 42 is character multiplex data read from the line memory 35. A lookup table for converting to R, G, B color data, and 37 for the R, G of the lookup table 42
D / A that converts G and B color data to analog video signals
It is a conversion circuit. The memory control circuit 34 reads character-multiplexed data for a predetermined line (for W lines) for each field from the VRAM 33 based on the character display position signal and transfers it to the line memory 35. By sequentially shifting the start line, the aspect ratio of the picture tube 28 is 1
The character multiplex signal is vertically scrolled in the lower area of the 6: 9 wide screen. The character multiplex signal receiving circuit 24 generates a YM signal for converting to a half luminance color and a YS signal for switching the switch 26 in addition to the R, G, B character multiplex signal analog signals.

Next, the operation will be described. The composite video signal demodulated by the receiving circuit 22 is inputted to the character multiplex signal decoder 31 of the character multiplex signal receiving circuit 24, the character multiplex signal is extracted and decoded, and the decoded character multiplex data is processed by the color data conversion processing unit 38. After the color data is converted by
Data to be displayed among the stored character multiplex data is written in the VRAM 33 in the bitmap format in accordance with the write control signal from the memory control circuit 34.

The operation of the color data conversion processing unit 38 will be described with reference to FIG. From the decoded character multiplexed data, determine whether the data is the foreground color or the background color. If the data is the foreground color,
The decoded data is stored in the memory 32. In the case of a background color, the decoded data is converted into a half-brightness color (YM color) and then stored in the memory 32.

Here, by the switching operation of the switch 26, as shown in FIG. 4A, only the video / chroma signal (TV) is displayed on the full screen 51 having an aspect ratio of 16: 9 which is a wide screen on the picture tube 28 . Figure 4 and the state of projection
As shown in (b), the full screen 51 is vertically divided into an upper screen portion 51a having a large number of lines and a lower side screen portion 51b having a small number of lines (W), and a video chroma signal is supplied to the upper screen portion 51a. It is possible to obtain a state in which the character multiple signal (character) is vertically scrolled and displayed on the lower side screen portion 51b. The upward arrow indicates the state of vertical scrolling.

A method of reading the character multiplex data from the VRAM 33 in order to realize the display of the character multiplex signal while vertically scrolling will be described with reference to FIG. Figure 5
Is for the case of upward vertical scrolling. The memory control circuit 34, based on the character display position signal,
In the 2n field, an odd number of W lines are read from the first line of the VRAM 33 (assuming W = 10,
Read up to the 9th line). It goes without saying that the lines are read out line by line and written in the line memory 35 sequentially. Next, in the 2n + 1 field, an even number of W lines are read from the second line (1
Up to the 0th line). Now, the lower screen portion 51b has 1
The character multiplex signal for the frame is displayed. Then, in the 2 (n + 1) field, the read start line is shifted by S lines (S = 4 in the figure),
The odd lines from the fifth line are read out for W lines (13
Up to the line). Next, in the 2 (n + 1) +1 field, the even lines from the sixth line are read out for W lines (up to the 14th line). Thus, the character multiplex signal for the next one frame is displayed on the lower side screen portion 51b. At this stage, VRAM 33 shifted by S lines
From the first line to the fourth line, the data to be displayed in the next cycle is fetched from the character multiplex data stored in the memory 32 and renewedly written. Similarly, the VRAM 33 is read up to the 480th line, but 4
The amount of W lines becomes insufficient as the 80th line is approached, but at this time, the process returns to the 1st line and the W lines are read. At this stage, data is updated from the first line to the (480-D) th line of the VRAM 33.

The above operation will be specifically described. In the 2n field, the lines [1, 3, 5, 7, 9] are read out,
In the 2n + 1 field, lines [2, 4, 6, 8, 1
0] is read, and in the 2 (n + 1) field, lines [5, 7, 9, 11, 13] are read and 2 (n + 1)
In the +1 field, lines [6, 8, 10, 12, 1
4] is read out, so that the upward vertical scrolling projection of the character multiplex signal is performed on the lower side screen portion 51b.

The vertical scroll may be downward. This will be described with reference to FIG. In the 2 m field, the odd lines from the 471th line of the VRAM 33 are read out by W lines (up to the 479th line, W = 10). Next, in the 2m + 1 field, the even lines from the 472nd line are read out by W lines (up to the 480th line). As a result, the character multiplex signal for one frame is displayed on the lower screen portion 51b. In addition, by proceeding steadily, for example, in the 2n field, 7 of the VRAM 33
W lines of odd lines are read from the line (up to the 15th line). Next, in the 2n + 1 field, the even lines from the 8th line are read out for W lines (up to the 16th line). As a result, the character multiplex signal for one frame is displayed on the lower screen portion 51b. continue,
In the 2 (n + 1) field, the read start line is shifted by S lines (S = 4 in the figure), and the odd lines from the third line are read by W lines (up to 11 lines). Then 4 in 2 (n + 1) +1 fields
W lines of even lines are read from the line (up to the 12th line). Now, in the lower side screen portion 51b, the following 1
The character multiplex signal for the frame is displayed. At this stage, the data to be displayed in the next cycle is fetched from the character multiplex data stored in the memory 32 and updated and written from the 12th line to the 16th line of the VRAM 33 shifted by S lines.

Similarly, the VRAM 33 is read up to the first line, but the W line becomes insufficient as it approaches the first line. At this time, the process returns to the 480th line and reads the W line. At this stage, VRA
The data is updated from the Dth line to the 480th line of M33.

The above operation will be specifically described. In the 2m field, lines [471, 473, 475, 477,
479] is read out, lines [472, 474, 476, 478, 480] are read out in the 2m + 1 field, and the process proceeds steadily, and for example, lines [7, 9, 11, 13, 15] are read out in the 2n field, and lines are read out in the 2n + 1 field. [8,10,12,14,16] is read, and in the 2 (n + 1) field, the line [3,
5, 7, 9, 11] are read, and lines [4, 6, 8, 10, 12] are read in 2 (n + 1) +1 fields.
In b, the downward vertical scroll projection of the character multiplex signal is performed.

Although omitted in the above description of the operation, VRA
The bitmap data read out from M33 by vertical scrolling as described above is sequentially written into the line memory 35 one line at a time, and is read from the line memory 35 by the display clock corresponding to the display on the lower side screen portion 51b. And the foreground color / back color in the color data conversion processing unit 38 is output.
The foreground color data generated by the scenery generation function is expanded into R, G, B color data by the lookup table 42, and D
In the A / A conversion circuit 37, analog character multiplexed signals (R, G,
(B signal) and is output from the character multiplex signal receiving circuit 24. Then, it is output to the picture tube 28 via the picture tube drive circuit 27 via the switch 26, and is displayed in the vertical scroll state on the lower side screen portion 51b.

The bitmap data and background color data generated in the foreground / background color generating function in the color data conversion processing unit 38 read out from the line memory 35, half-bright color control in the color data conversion processing unit 38 It is input to the signal generation circuit 43 and the character multiplex signal / video / chroma signal switching signal generation circuit 44. The half-brightness color control signal generation circuit 43 generates a half-brightness color control signal, that is, a YM signal corresponding to the background color, and outputs the YM signal to the video / chroma signal processing circuit 23. The video / chroma signal processing circuit 23 converts the video / chroma signal into a half-luminance color corresponding to the background color. The character multiplex signal / video / chroma signal switching signal generation circuit 44 generates a character multiplex signal / video / chroma signal switching signal, that is, a YS signal corresponding to the background color and outputs it to the switch 26. As a result, the lower side screen portion 51 of the picture tube 28 is
In b, the background color of the character multiplex signal (foreground color) that is vertically scrolled and displayed is a half-luminance color, and the video / chroma signal with a reduced luminance level is displayed behind it. The video chroma signal with the reduced luminance is represented by a halftone dot in FIG. 4 (b).

As is apparent from FIG. 4B, a video / chroma signal is projected on the upper screen portion 51a having a large area in the full screen 51 having an aspect ratio of 16: 9 which is a wide screen, and the Small bottom screen part 51
In b, the character multiplex signal (foreground color) is projected in the vertical scrolling state, and the video / chroma signal is projected in the half-bright color behind the background color that has become the half-bright color around it. As a result, both the video / chroma signal and the vertically scrolled character multiplex signal are easy to see. Since there is no image-free portion, the video / chroma signal can be displayed on the upper screen portion 51a in a large size for easy viewing. Further, the lower side screen portion 51b has a small area, but since the character multiplex signal is vertically scrolled, there is no problem for viewing, and the full screen (wide screen) is effectively used.

[Embodiment 2] The overall configuration of the character multiplex television receiver according to the second embodiment is the same as that of FIG. 1, and the internal configuration of the character multiplex signal receiving circuit 24 is the same as that of FIG. Therefore, illustration and description are omitted. FIG. 7 is a flowchart of the color data conversion processing unit 38a in the character multiplex television receiver according to the second embodiment. The color data conversion processing unit 38a performs processing at the same location as the color data conversion processing unit 38 in FIG.
In FIG. 7, what is different from FIG. 3 of the first embodiment is that
In the case of the foreground color, the character multiplex-decoded data is converted into a fixed foreground color having a fixed color type and stored in the memory 32. The fixed foreground color is, for example, white, and white is preferable.

The VRAM 3 is used for vertical scroll display.
The method of sequentially reading the start line for reading from line 3 by S lines and writing for W lines in each field in the line memory 35 is similar to that of the first embodiment.

The bit map data read out from the VRAM 33 by vertical scrolling as described above is sequentially written into the line memory 35 one line at a time, and the line memory is generated by the display clock corresponding to the display on the lower side screen portion 51b. 35, and the lookup table 4
2 is converted into R, G, B color data, and is converted into an analog R, G, B character multiplex signal by the D / A conversion circuit 37 and output from the character multiplex signal reception circuit 24. Then, it is output to the picture tube 28 through the picture tube drive circuit 27 via the switch 26, and is displayed in the vertically scrolling state as the fixed foreground color (for example, white) on the lower side screen portion 51b.

The bit map data read from the line memory 35 includes the half-brightness color control signal generation circuit 43 and the character multiplex signal / video / chroma signal switching signal generation circuit 4.
4 is input. The half-brightness color control signal generation circuit 43 generates a half-brightness color control signal, that is, a YM signal, and outputs it to the video / chroma signal processing circuit 23. The video / chroma signal processing circuit 23 converts the video / chroma signal into a half-luminance color corresponding to the YM signal. A character multiplex signal / video / chroma signal switching signal generation circuit 44 generates a character multiplex signal / video / chroma signal switching signal, that is, a YS signal, and switches 2
Output to 6.

As a result, the background color of the character multiplex signal (fixed foreground color (for example, white)) vertically scrolled and projected on the lower screen portion 51b of the picture tube 28 becomes a half-luminance color, and the luminance behind it. A video chroma signal with reduced level will be displayed. In FIG. 8B, the character multiplex signal of the fixed foreground color (for example, white) is shown in a white state, and the video / chroma signal with reduced luminance is shown by halftone dots. Vertical scrolls are indicated by upward arrows. Since the vertically-scrolled character multiplex signal is displayed in a fixed foreground color (for example, white), the character is displayed more easily than in the first embodiment.

[Third Embodiment] The overall configuration of the character multiplex television receiver according to the third embodiment is the same as that of FIG. 1, and the internal configuration of the character multiplex signal receiving circuit 24 is the same as that of FIG. Therefore, illustration and description are omitted. FIG. 10 is a flowchart of the color data conversion processing unit 38b in the character multiplex television receiver according to the third embodiment. The color data conversion processing unit 38b performs processing at the same location as the color data conversion processing unit 38 in FIG. 10 differs from FIG. 3 of the first embodiment and FIG. 7 of the second embodiment in that the decoded data is character / text based on the data unit parameter value of the character multiplex decoded data.
It is determined whether it is an external character or a photo graphic. In the case of a character / external character, the foreground color is set as the fixed foreground color, and the background color is converted to the YM color. In the case of a photo graphic, the decoded data is output as it is and stored in the memory 32. The fixed foreground color is white, for example,
White is preferred.

The VRAM 3 is used for vertical scroll display.
The method of sequentially reading the start line for reading from line 3 by S lines and writing for W lines in each field in the line memory 35 is similar to that of the first embodiment.

Bit map data read from the VRAM 33 by vertical scrolling as described above is sequentially written into the line memory 35 one line at a time, and the line memory is generated by the display clock corresponding to the display on the lower side screen portion 51b. 35, and the lookup table 4
2 is converted into R, G, B color data, and is converted into an analog R, G, B character multiplex signal by the D / A conversion circuit 37 and output from the character multiplex signal reception circuit 24. Then, it is output to the picture tube 28 through the picture tube drive circuit 27 via the switch 26, and is displayed in the vertically scrolling state as the fixed foreground color (for example, white) on the lower side screen portion 51b.

The bit map data read from the line memory 35 includes the half-brightness color control signal generation circuit 43 and the character multiplex signal / video / chroma signal switching signal generation circuit 4.
4 is input. The half-brightness color control signal generation circuit 43 generates a half-brightness color control signal, that is, a YM signal, and outputs it to the video / chroma signal processing circuit 23. The video / chroma signal processing circuit 23 converts the video / chroma signal into a half-luminance color corresponding to the YM signal. A character multiplex signal / video / chroma signal switching signal generation circuit 44 generates a character multiplex signal / video / chroma signal switching signal, that is, a YS signal, and switches 2
Output to 6.

Since the vertically-scrolled character multiplex signal is displayed in a fixed foreground color (for example, white), a more easily visible character is displayed than in the first embodiment, and the photo image is displayed.
Since graphics are displayed without color data conversion, graphics are more vivid than in the second embodiment.

[Embodiment 4] The overall configuration of the character multiplex television receiver according to the fourth embodiment is the same as that of FIG. 1, and the internal configuration of the character multiplex signal receiving circuit 24 is the same as that of FIG. Therefore, illustration and description are omitted. FIG. 11 is a flowchart of the color data conversion processing unit 38c in the character multiplex television receiver according to the fourth embodiment. The color data conversion processing unit 38c performs processing at the same location as the color data conversion processing unit 38 in FIG. 11 differs from FIG. 3 of the first embodiment, FIG. 7 of the second embodiment, and FIG. 10 of the third embodiment in that, based on the data unit parameter value of the character multiplex decoded data, the decoded data is character / external character. Whether it is a photo or a graphic, if it is a character / gaiji,
The foreground color is a fixed foreground color, and the background color is converted to YM color. In the case of a photo graphic, the foreground color and the background color are discriminated. In the case of the foreground color, the decoded value is output, and in the case of the background color, the decoded value is a transparent color (transparent color). In the case of, the background color is converted to YM color,
When the color is not transparent, the decoded value is output and stored in the memory 32.

The fixed foreground color is, for example, white, and white is preferable.

VRAM 3 for vertical scrolling display
The method of sequentially reading the start line for reading from line 3 by S lines and writing for W lines in each field in the line memory 35 is similar to that of the first embodiment.

Bit map data read from the VRAM 33 by vertical scrolling as described above is sequentially written into the line memory 35 one line at a time, and the line memory is generated by the display clock corresponding to the display on the lower side screen portion 51b. 35, and the lookup table 4
2 is converted into R, G, B color data, and is converted into an analog R, G, B character multiplex signal by the D / A conversion circuit 37 and output from the character multiplex signal reception circuit 24. Then, it is output to the picture tube 28 through the picture tube drive circuit 27 via the switch 26, and is displayed in the vertically scrolling state as the fixed foreground color (for example, white) on the lower side screen portion 51b.

The bit map data read from the line memory 35 includes the half-brightness color control signal generation circuit 43 and the character multiplex signal / video / chroma signal switching signal generation circuit 4.
4 is input. The half-brightness color control signal generation circuit 43 generates a half-brightness color control signal, that is, a YM signal, and outputs it to the video / chroma signal processing circuit 23. The video / chroma signal processing circuit 23 converts the video / chroma signal into a half-luminance color corresponding to the YM signal. A character multiplex signal / video / chroma signal switching signal generation circuit 44 generates a character multiplex signal / video / chroma signal switching signal, that is, a YS signal, and switches 2
Output to 6.

Since the vertically-scrolled character multiplex signal is displayed in a fixed foreground color (for example, white), the character is displayed more easily than in the first embodiment and the photo image is displayed.
Since the foreground color of the rough is displayed as it is, the graphics are vivid compared to the second embodiment. In addition, full
By setting the transparent color portion of the otographic to the YM color, the image is easier to see than the third embodiment.

[0039]

According to the television receiver for character multiplex broadcasting of the present invention, the background color around the character foreground color is set to a half-brightness state in the area where the character multiplex signal is displayed on the picture tube screen. Since the video chroma signal of a half-bright color is displayed behind, the characters are easy to see. If the foreground color is a fixed foreground color that defines the type of color, especially if the color is white, then the characters can be made easier to see. When vertically scrolling the characters, the vertical width of the character multiplex signal projection area can be made small, and the vertically scrolled characters are easy to see.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a character multiplex television receiver according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing an internal configuration of a character multiplex signal reception circuit in the case of the first embodiment.

FIG. 3 is a flowchart of a color data conversion process in the case of the first embodiment.

FIG. 4 is a diagram showing a two-screen display in a state in which a character multiplex signal is vertically scroll-projected in the case of the first embodiment.

FIG. 5 is a diagram illustrating a method of reading character multiplex data from a VRAM for realizing the projection of a character multiplex signal while vertically scrolling upward.

FIG. 6 is a diagram illustrating a method of reading out character multiplex data from a VRAM for realizing the projection of a character multiplex signal while vertically scrolling downward.

FIG. 7 is a flowchart of color data conversion processing according to the second embodiment.

FIG. 8 is a diagram showing a two-screen display in a state in which a character multiplex signal is vertically scrolled in the case of the second embodiment.

FIG. 9 is a block diagram showing an internal configuration of a color data conversion circuit in the case of a conventional technique.

FIG. 10 is a flowchart of color data conversion processing according to the third embodiment.

FIG. 11 is a flowchart of color data conversion processing according to the fourth embodiment.

[Explanation of symbols]

21 ... Antenna 22 ... Reception circuit 23 ... Video / chroma signal processing circuit 24 ... Character multiplex signal reception circuit 25 ... Sync separation circuit 26 ... Switch 27 ... Picture tube drive circuit 28 ... Picture tube 29 ... ... Horizontal deflection circuit 30 ... Vertical deflection circuit 31 ... Character multiplex signal decoder 32 ... Memory 33 ... VRAM 34 ... Memory control circuit 35 ... Line memory 36 ... Color data conversion circuit 37 ... D / A conversion Circuit 38 ... Color data conversion processing unit 41 ... Foreground color / background color generation circuit 42 ... Look-up table 43 ... Half-brightness color control signal generation circuit 44 ... Character multiplex signal / video / chroma signal switching signal generation circuit 51a ... upper side screen portion 51b ... lower side screen portion

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Claims (8)

(57) [Claims] 1. A video / chroma signal processing circuit for demodulating a received composite video signal, a character multiplex signal receiving circuit for extracting a character multiplex signal superimposed on the composite video signal, and a video / chroma signal processing circuit A video / chroma signal and a switch for simultaneously displaying the character multiplex signal from the character multiplex signal receiving circuit on a picture tube screen are provided, and the character multiplex signal receiving circuit includes a character multiplex signal for decoding the character multiplex signal. A decoder,
A foreground color and a background color are generated from the decoded character multiplex data, and the foreground color is a fixed foreground color with a fixed color type.
Color data conversion processing means for converting the background color into YM color, a memory for storing the color data converted data, and a line memory for displaying the stored bitmap for each line. A lookup table for converting the bitmap data into RGB color data, a D / A conversion circuit for converting the RGB converted data into an analog RGB signal, and a half-brightness color control signal (from the bitmap data from the line memory). YM signal) and supplies it to the video / chroma signal processing unit to supply the half-luminance color control signal generation means, and a character multiplex signal / video / chroma signal switching signal (YS signal) from the bit map data from the line memory. Character multiplexed signal / video generated and supplied to the switch
A chroma signal switching signal generating means is provided so that the background color around the character foreground color is set to a half-brightness state in the character multiplex signal display area of the picture tube screen so that the video chroma signal is displayed behind it. A television receiver for character multiplex broadcasting, characterized in that 2. The television receiver for character multiplex broadcasting according to claim 1 , wherein the fixed foreground color is white. 3. A video for demodulating a received composite video signal.
・ Chroma signal processing circuit and character multiplex signal superimposed on composite video signal
Character multiplex signal receiving circuit and video chroma from the video chroma signal processing circuit
Signal and the character multiplex signal from the character multiplex signal receiving circuit
Equipped with a switch for simultaneously displaying on the picture tube screen
At the same time, the character multiplex signal receiving circuit has a character multiplex signal decoder for decoding the character multiplex signal , and the data is a character
/ Determines whether the external character or photo graphic
Convert foreground color to fixed foreground color and background color to YM color
In the case of photo graphics, color data conversion processing
Stores the color data conversion processing means having a function not to perform and the data processed by the color data conversion processing means.
Memory and a raster for displaying the stored bitmap line by line.
An in-memory and rule that converts bitmap data into RGB color data.
Converts the conversion table and RGB converted data into analog RGB signals
Half-luminance color control from the D / A conversion circuit and the bit map data from the line memory.
Signal (YM signal) to generate the video / chroma signal.
The half-luminance color control signal generating means to be supplied to the signal processing section and the character multiplex transmission from the bit map data from the line memory.
No./Video/chroma signal switching signal (YS signal) generated
Character multiplex signal / video
A chroma signal switching signal generating means is provided, and in the display area of the character multiplex signal of the picture tube screen, characters /
The foreground color of the external character is fixed to the foreground state, and the spine around the foreground color
Put the scenery in half-brightness, and let the photo graphics
The video chroma signal is displayed behind it.
A television receiver for character multiplex broadcasting, which is characterized in that 4. The television receiver for character multiplex broadcasting according to claim 3 , wherein the fixed foreground color is white. 5. A video for demodulating a received composite video signal.
・ Chroma signal processing circuit and character multiplex signal superimposed on composite video signal
Character multiplex signal receiving circuit and video chroma from the video chroma signal processing circuit
Signal and the character multiplex signal from the character multiplex signal receiving circuit
Equipped with a switch for simultaneously displaying on the picture tube screen
At the same time, the character multiplex signal receiving circuit has a character multiplex signal decoder for decoding the character multiplex signal , and the data is a character
/ Determines whether the external character or photo graphic
In this case, the foreground color is fixed and the background color is YM.
Foreground color is converted and converted in the case of photo graphic
For the background color,
Indicates that the data is transparent (transparent).
If it is not transparent, the background color is converted to YM color and
Data conversion processing having a function not to perform data conversion processing
And means for storing the data processed by the color data conversion processing means.
Memory and a raster for displaying the stored bitmap line by line.
An in-memory and rule that converts bitmap data into RGB color data.
Converts the conversion table and RGB converted data into analog RGB signals
Half-luminance color control from the D / A conversion circuit and the bit map data from the line memory.
Signal (YM signal) to generate the video / chroma signal.
The half-luminance color control signal generating means to be supplied to the signal processing section and the character multiplex transmission from the bit map data from the line memory.
No./Video/chroma signal switching signal (YS signal) generated
Character multiplex signal / video
A chroma signal switching signal generating means is provided, and in the display area of the character multiplex signal of the picture tube screen, characters /
The foreground color of the external character is fixed to the foreground state, and the spine around the foreground color
Makes the scene a half-bright color and the foreground color of the photo graphic
Is left as it is, the transparent back of the photo graphic
The scenery is half-bright and the photographic transparency is transparent.
Video behind it with no background color
・ Characterized by displaying the chroma signal
A television receiver for teletext. 6. The television receiver for character multiplex broadcasting according to claim 5 , wherein the fixed foreground color is white. Wherein said teletext signal receiving circuit according to claim, characterized in that it is configured to convert the teletext signal to the state issued movies in vertical scrolling state at lower or upper side of the picture tube screen 1 The television receiver for teletext according to any one of claims 1 to 6 . 8. The television receiver for character multiplex broadcasting according to any one of claims 1 to 7 , wherein the picture tube is constructed with an Asbect ratio of 16: 9.