JPH08331527A - Character information signal receiver - Google Patents

Abstract

PURPOSE: To provide a character information signal receiver on which characters on a screen of a television receiver is displayed in a display form selected by a viewer (user) without depending upon the character display method of received teletext. CONSTITUTION: A video signal received from an input terminal 1 is given to a data extract means 2, in which a character signal superimposed on a signal for a vertical blanking period (VB1) is extracted and the signal is decoded by a decoding means 3 and fed to a display conversion means 4. Moreover, a display conversion means 4 converts a code of a signal into other form such as from a capital letter into a small letter or vice versa based on a selection signal from a selection means 5 and supplys a character code to a display control means 6. The display control means 6 reads dot of a character from a character font storage means 21 according to the character code from the display control means 4 and gives a display signal output to an output terminal 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a character information signal receiver, and more particularly to a character information signal according to a broadcasting system for displaying a character synchronized with a voice on a screen of a television receiver and receiving the character information signal. The present invention relates to a character information signal receiving device capable of displaying characters by changing the font of characters displayed on the screen.

[0002]

2. Description of the Related Art Teletext is internationally called teletext and was developed in England around 1972. If television means "see distant things", teletext means "read distant things".

In Europe, the teletext called teletext has been available since 1976 in the British broadcasting station BBC.
Broadcast started by. The original purpose of teletext was started for the hearing impaired, but in recent years, information for the general public has been enriched, and various information such as weather forecasts, news, and traffic information has come to be provided. ing.

The teletext system in Japan was also developed at about the same time as the British teletext, but it was devised because of the peculiarity of Japanese (Kanji).
A test broadcast was started in 983, and N was released in November 1986.
The main broadcasting has started from HK and NTV.

In addition, there are only one teletext broadcast in the United States.
From March 980, ABC, NBC and PBS (Publi
c Broadcasting Service: Broadcasting is started by the US public broadcasting service.

By the way, the character multiplex broadcasting in the United States is
It is called closed captioning and is mainly broadcast for people with hearing loss. In recent years, all the programs of prime time (time zone with a high audience rating at night) provided by the three major networks (CBS, ABC, NBC) are broadcast with captions. Moreover, these are not limited to TV programs, but are expanding to package media such as video software and video discs, and cable TV. However, in Japan,
Just like captions, services that synchronize drama lines, news manuscripts, etc. with television broadcast videos are only a part of the service, and there are great expectations in the future.

Next, a brief caption broadcasting system which is a character multiplex broadcasting in the United States will be briefly described. In addition, including the following examples, as character multiplex broadcasting,
The closed caption broadcasting system in the United States will be taken as an example for explanation.

FIG. 6 is a waveform diagram of the vertical blanking interval (VBI) showing the multiplexing position of the caption data. FIG. 7 shows a waveform diagram of the multiplexed caption signal.

As shown in FIG. 6, the caption information 32
Is the 21st scanning line (line 2) of the portion other than the television video signal 31 in the vertical blanking period (VBI) of the first field.
1) is multiplexed. The character signal can theoretically be superposed between the line 10 (line 273) and the line 21 (line 284) of the "horizontal scanning line" in the vertical blanking period (VBI), but the existing television image reception is possible. For compatibility with other devices, character signals are currently multiplexed on the 21st scan line (line 21) of the first field. In the caption information format defined by the US NCI (National Captioning Institute), the method of multiplexing the caption information on the line 21 of the first field is “field 1 mode” and the caption information on the line 284 of the second field. The method to multiplex is defined as "field 2 mode", but in 1976, F
The CC (Federal Communications Commission) has assigned line 21 for subtitled broadcasting, which is currently in the United States as "Field 1
・ "Mode" is used.

On the other hand, as can be seen from FIG. 7, the caption signal is a 16-bit NRZ (nonreturn to zero: 2).
(Valued signal) data 35, which is composed of two sets (one word) of character codes which are a combination of a 7-bit ASCII code and a 1-bit parity code. Further, the 21st scanning line (line 21) of the first field has a horizontal synchronizing signal 37, a color burst signal 33, and the NRZ data 3 from the beginning.
5, clock run-in signal 34 for synchronizing
The start code 36 and the NRZ data 35 are arranged in this order. The NRZ data 35 is CCI.
A binarized signal in which a blanking level 0IRE unit (1IRE unit = 1/140 [V]) is set to 0 and a level equal to or higher than a predetermined level is set to 1 according to the recommendation of R (International Radio Committee). is there.

The NRZ data 35 has 112 kinds of character codes defined by the standard, which are basically ASCII codes. The NRZ data 35 has a control code to which various commands are assigned in addition to the character code. The control code is composed of 2 bytes and constitutes one command.

As described above, the closed caption is the first part of the vertical blanking interval (VBI) of the television signal.
The caption signal superimposed on the 21st scan line (line 21) of the field is connected to the television receiver,
Alternatively, the built-in closed caption signal receiving device extracts and decodes the caption signal from the television signal and displays it as character information on the screen of the television receiver.

By the way, as described above, the content (character code or control code) of the NRZ data 35 specifies the character type, the character attribute, the display format, the display position, etc., and based on this. Although characters are displayed on the screen, there are roughly two display forms of closed captions. That is, there are two types, such as a superimpose of a movie, a caption mode in which dialogue is displayed on a part of the screen, and a text mode in which the background screen is displayed so as to cover the entire screen. Text mode is April 1, 1991
By the FCC (Federal Communications Commission) regulation on the 2nd, it is an optional function and the number of characters displayed is 3.
It is 2 characters x 15 lines. On the other hand, the caption mode can display up to 32 characters per line, and the number of lines displayed is
The maximum is 4 lines. Both screens also have a scroll function.

As mentioned above, the character multiplex broadcasting for each region (mainly closed captions in the United States) has been described.
In both cases, the characters displayed on the screen of the television receiver are those displayed from the broadcasting station as they are, and the font of the displayed characters cannot be changed and displayed on the receiver side. For example, whether the English characters displayed on the screen are displayed in uppercase or lowercase depends on the signal transmitted from the broadcasting station (caption signal, etc.).
It was impossible to choose on the receiving side.

FIG. 8 is a diagram showing a display example of the screen of the television receiver in the case where the signal transmitted from the broadcasting station is encoded with English characters in upper case only.

In FIG. 8, it can be seen that the displayed characters are all uppercase letters.

When the signals sent from these broadcasting stations are in a free font on the receiver side, for example, English characters, all the sentences are displayed in lowercase letters, italic fonts are displayed, and the like. In the case of words, it is convenient if the block font is changed to Mincho font or line font, and the font of characters can be changed according to the user's preference.

[0018]

As described above, in the conventional character information signal receiving apparatus, for example, when the transmitting side transmits the English characters in only uppercase letters, the television screen displays characters in only uppercase letters. Depending on the viewer, it may be more difficult to read than a normal mixed-case sentence. On the contrary, for a viewer who prefers to display only uppercase letters, it is not preferable for the transmitting side to transmit English letters in mixed case.

Therefore, the present invention has been made in view of the above problems.
Provided is a character information signal receiving device capable of displaying a character on a screen of a television receiver in a display format selected by a viewer (user) regardless of a display format of a transmitted character. That is the purpose.

[0020]

According to a first aspect of the present invention, there is provided a character information signal receiving apparatus, wherein a means for inputting a video signal and a character superposed in a state encoded in a vertical blanking period of the video signal. Encoded character information consisting of a code or control code is extracted from the vertical blanking period, encoded character information extracting means, decoding means for decoding the encoded character information extracted by the encoded character information extracting means, and decoding by the decoding means. The display format selecting means for selecting the display format of the character information consisting of the selected character code, and the display format of the character information consisting of the character code to the display format selected by the display format selecting means, Display format conversion means for outputting the displayed display format as a character code, and the display format The character / font storage means having the character dot data corresponding to the character code output from the conversion means, and the character dot data corresponding to the character code output from the display format conversion means are read from the character / font storage means. And display control means for outputting as a display signal.

A character information signal receiving apparatus according to a second aspect of the present invention is the character information signal receiving apparatus according to the first aspect, wherein the encoded character information is the 21st horizontal scan of the first field which is a vertical blanking period. It is characterized in that it is superimposed on the line and is composed of a 16-bit NRZ signal.

A character information signal receiving device according to a third aspect of the present invention is the character information signal receiving device according to the first or second aspect, in which the display format converting means includes character information consisting of the character code in English characters. In this case, one character at the beginning of the sentence is capitalized, and all other characters are displayed in lowercase except for a predetermined term.

A character information signal receiving apparatus according to a fourth aspect of the present invention is the character information signal receiving apparatus according to the first, second or third aspect, wherein the character / font storage means has a plurality of various fonts. When the display format selecting means selects the font, the characters are displayed in the font.

[0024]

According to the first aspect of the invention, the display format of the received character information is converted according to the display format selected by the display format selecting means. Regardless of the display format of the written character information, the characters in the font (typeface) desired by the user,
It is possible to display teletext programs on a television screen.

According to the second or third aspect of the invention, when the character information consists of English characters, the display format selecting means converts uppercase letters to lowercase letters or uppercase letters to lowercase letters as necessary. Therefore, it is possible to view a teletext program in a font (uppercase or lowercase) that the user desires to see easily.

According to the invention as set forth in claim 4, since a plurality of various fonts are prepared in the character / font storage means, for example, English characters in italic or Gothic etc. Can be displayed on the television screen in a font desired by the user, such as Mincho or line style.

[0027]

EXAMPLES Examples will be described with reference to the drawings. FIG. 1 is a block diagram showing a functional configuration of a character information signal receiving apparatus according to the present invention.

In FIG. 1, the video signal input from the input terminal 1 is extracted by the data extracting means 2 as a character signal superimposed on the vertical blanking period (VBI), and the decoding means 3 constituting the control means 8 is obtained. And is supplied to the display conversion means 4 which also constitutes the control means 8. Further, the display conversion means 4 performs conversion (code conversion) of, for example, uppercase letters of English letters to lowercase letters or vice versa based on the selection signal from the selection means 5, and displays the resulting character code. It is supplied to the control means 6. Then, the display control means 6 reads the character data from the character font storage means 21 according to the character code from the display conversion means 4 and supplies it to the output terminal 7 as a display signal output. The control means 8 composed of the decoding means 3 and the display conversion means 4 is
In addition to the decoding of the character signal and the change of the character code based on the instruction from the selecting means 5, as described above, the character displayed on the screen according to the content (character code or control code) of the NRZ data 35. It also controls the display of attributes, display format, display position, and so on.

On the other hand, FIG. 2 is a block diagram showing an example of a concrete circuit configuration of the character information signal receiving apparatus of the present invention. Further, FIG. 3 is a flowchart showing the control contents of the control circuit 8.

A video signal on which a closed caption signal is superimposed is input to the input terminal 1 and supplied to the data extracting circuit 2. The data extracting circuit 2 extracts the caption signal from the input video signal and supplies it to the control circuit 8. The control circuit 8 includes a CPU 9,
It is composed of a read-only ROM 10 in which a control program and the like are stored, and a readable / writable RAM 11 used temporarily, and functions in the same manner as the decoding means 3 and the display conversion means 4 shown in FIG. The selection signal from the selection key 5 is supplied to the CPU 9. The output of the control circuit 8 is supplied to the display control circuit 6, and the display control circuit 6 reads character dot data from the character ROM 12 based on the output of the control circuit 8 and outputs a display signal to the output terminal 7. To do.

An example of the operation of the character information signal receiving apparatus configured as described above will be described with reference to the flowchart of FIG.

The control circuit 8 to which the caption signal is supplied from the data sampling circuit 2 reads data from the input caption data (step s).
1), the decoding process of the data (step s2) is performed. Here, the decoding process is to determine what kind of display process is to be performed by decoding and analyzing the read data, that is, determining the display control of the attributes, display format, display position, etc. of the characters displayed on the screen. (Including decoding and analysis of control data).

Next, the control circuit 8 judges whether or not the character display on the screen is requested as a result of the decoding processing (step s3). It is determined by the selection key 5 whether or not a display character conversion request is made (step s
4) If the display character conversion request is not made,
The character decoded in step s2 is displayed as it is (step s6). The character display processing is performed by supplying the display control circuit 6 with the attributes of the display character, the display format, the display position, the character code, and the like. Then, the display control circuit 6 reads the dot data of the character based on the character code from the character ROM 12 in accordance with the data (character code or the like) supplied from the control circuit 8, and makes a predetermined display on the display screen. A display signal for displaying the position with a predetermined attribute is generated and output to the output terminal 7.

On the other hand, in step s4, when the conversion key for the display character is requested (made) by the selection key 5, the character code decoded in step s2 is used as the display character by the selection key 5. The display conversion process is performed based on the conversion request (step s5), and the process of displaying the converted character is performed (step s5).
6).

FIG. 4 is a flow chart showing an example of the display conversion process.

Next, the display conversion processing (processing of step S5) will be described with reference to the flowchart shown in FIG. In addition, the selection key 5 in the present embodiment
Is "Display conversion OFF", "Conversion to uppercase display",
The description will be made assuming that three modes of "converting to uppercase / lowercase mixed display" can be selected. However, select key 5
When "Display conversion OFF" is selected, step s5 is not executed (because the process proceeds from step s4 to step s6).

First, it is judged which mode is selected with the selection key 5 (step t1),
If "convert to upper case" is selected, the process proceeds to step t3, and if the character code (character) decoded in step s2 of FIG.
Returning to step s6 in FIG. 3, if it is an English lower case letter, it is converted to an upper case letter (step t4), and returning to step s6 in FIG.

When "convert to upper / lower case mixed display" is selected in step t1, the process proceeds to step t2, and the position where the character code (character) decoded in step s2 of FIG. It is determined whether or not it is the beginning of a sentence, and if the position to be displayed is the beginning of the sentence and the character code (character) is a lowercase letter, it is converted to an uppercase letter (steps t3 and t4), and the process returns to step s6 in FIG. If the position to be displayed is other than the beginning of the sentence and the character code (character) is an uppercase letter, it is converted to a lowercase letter (steps t5 and t6), and the process returns to step s6 in FIG.

By the way, in steps t3 and t5 of FIG. 4, a method of discriminating an uppercase letter or an alphabetic character, a method of converting an uppercase letter into an uppercase letter in step t4 in the figure, and an uppercase letter in step t6 in the figure. In this embodiment, the character code of the character ROM 12 is ASCII.
This is done by using the I code.

That is, the capital letters are 41h-5Ah,
Since the English characters are expressed by 61h to 7Ah,
If the character code decoded in step s2 is in the range of 41h to 5Ah, it is determined to be an uppercase letter, and if it is in the range of 61h to 7Ah, it is determined to be an lowercase letter. Then, the conversion from the English capital letter to the English character (step t6 in FIG. 4) can be performed by adding 20h to the character code which is decoded in step s2 in FIG. 3, and the conversion from the English lowercase letter to the English capital letter ( Figure 4
Step t4) of the
It can be converted by reducing h.

The method for determining whether the position where the character code (character) decoded in step s2 of FIG. 3 should be displayed is the beginning of a sentence (step t2) is as follows. That is, when any of the ending mark ".", Exclamation mark "!", And question mark "?" Is detected as the character code (character) decoded in step s2 of FIG. 3, the flag in the RAM 11 is changed. set.
Then, the character code (English character) decoded next after the flag is set is determined to be the first character. At this point, the flag in the RAM 11 is cleared. It should be noted that the candidates for the character at the beginning of the sentence are only English characters, and characters such as symbols, numbers, and spaces other than the English letters are not treated as the characters at the beginning of the sentence.

FIG. 5 shows an example of a screen display when "convert to upper / lower case mixed display" is selected by the selection key 5 when only uppercase letters are sent as the caption signal (character).

As can be seen from FIG. 5, the English letters (uppercase letters) originally displayed on the screen as shown in FIG.
You can see that it has been converted to mixed case display.

In this embodiment, two types of display conversion types, "convert to uppercase display" and "convert to uppercase / lowercase mixed display", have been described, but similarly, "convert to lowercase display". The mode can also be easily realized.

[Conversion to mixed case display]
In the above, "I" meaning "I" may be displayed in uppercase. In this case, in the display conversion process,
When the character code is decoded in the order of "space", "I" or "i", "space", or in the order of "space", "I" or "i", "'". Can be realized by performing processing so as to display "I" in capital letters even at the beginning of the sentence.

Furthermore, words such as "U.S.A" that have a period every other character may be judged as abbreviations and displayed in capital letters, or "FBI" or the like. Words that should be capitalized for all letters, and "Ma
Proper nouns such as "ria" and "Japan" whose uppercase letters are appropriate only for the first letter are stored in advance in ROM or RAM (as a reserved word), and those words (reserved words) are stored. ) May be displayed in a previously stored display format.

Further, the character signals sent from these broadcasting stations may be displayed in a free font on the receiver side, for example, in the case of English characters, the entire sentence may be displayed in italic or bold tones, or the like. In the case of Japanese, the block type may be displayed in Mincho typeface or line typeface, or the font of characters may be changed according to the preference of the user. In this case, the character ROM 12
The ROM 10 or the like may be provided with various fonts, and the selection key 5 may be used to select the font.

[0048]

As described above, according to the present invention, whether the English character encoded in the character signal (caption signal or the like) by the transmitting side is uppercase or lowercase, The display format regarding lowercase letters can be displayed in the format selected by the user (viewer), and more readable character information can be provided to the user (viewer).

[Brief description of drawings]

FIG. 1 is a block diagram showing a functional configuration of a character information signal receiving device according to the present invention.

FIG. 2 is a block diagram showing an example of a specific circuit configuration of a character information signal receiving device according to the present invention.

FIG. 3 is a flowchart showing control contents of a control circuit.

FIG. 4 is a flowchart showing an example of a display conversion process.

FIG. 5 is a screen display example in the case where “uppercase / lowercase mixed display” is selected by the selection key when only uppercase letters are sent as the caption signal (character).

FIG. 6 is a waveform diagram of a vertical blanking interval (VBI) showing a multiplexing position of caption data.

FIG. 7 is a diagram showing a waveform of a multiplexed caption signal.

FIG. 8 is a diagram showing a display example of a screen of a television receiver in the case where a signal transmitted from a broadcasting station is encoded with English characters in upper case only.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Input terminal 2 ... Data extracting means 3 ... Decoding means 4 ... Display conversion means 5 ... Selection means 6 ... Display control means 7 ... Output terminal 8 ... Control means 21 ... Character / font storage means

Claims (4)

[Claims] 1. A unit for inputting a video signal, and encoded character information consisting of a character code or a control code superimposed in a state encoded in a vertical blanking period of the video signal is extracted from the vertical blanking period. Encoded character information extracting means, decoding means for decoding encoded character information extracted by the encoded character information extracting means, and display format selecting means for selecting a display format of character information composed of character codes decoded by the decoding means And a display format conversion means for converting a display format of character information consisting of the character code into a display format selected by the display format selection means, and outputting the converted display format as a character code, the display format Character code corresponding to the character code output from the conversion means And a character / font storage unit having a font data, and a display control unit for reading out character dot data corresponding to the character code output from the display format conversion unit from the character / font storage unit and outputting it as a display signal. A character information signal receiving device characterized by the above. 2. The encoded character information is superimposed on the 21st horizontal scanning line of the first field, which is a vertical blanking period, and is composed of a 16-bit NRZ signal. Character information signal receiving device. 3. The display format converting means, when the character information consisting of the character code is composed of English characters, capitalizes one character at the beginning of the sentence and all other characters are lowercase except for a predetermined term. Claim 1 characterized by displaying
Alternatively, the character information signal receiving device described in 2. 4. The character / font storage means has a plurality of various fonts, and when the font is selected by the display format selection means, the characters are displayed by the font. The character information signal receiving device according to claim 1, 2, or 3.