KR100188276B1 - Sub-channel language distinction display method of televiewer option caption signal - Google Patents

Abstract

The present invention relates to a subchannel language discrimination display method of a viewer-selective caption signal, and more particularly, to a method for receiving a viewer-selective caption broadcast in which a caption signal is transmitted on one scanning line for every field of the television signal. Detecting an even field by detecting a vertical synchronization signal; Detecting the presence or absence of a caption signal on the detected field; Checking whether it is a control code or a character code by caption data extracted from the caption signal; In the case of the character code, determining the character code value of the caption data to determine whether it is a registered language; And displaying a non-registered language on the screen if it is not a registered language.

Therefore, in the present invention, when the language received through the subchannel is an unregistered language, the viewer can recognize it by displaying it.

Description

Sub channel language discrimination method of viewer-selectable subtitle signal

1 is a block diagram showing the configuration of a television broadcasting system for viewer-selective closed caption broadcasting according to the present invention.

2 is a block diagram showing the configuration of a television receiver for receiving viewer-selective closed captioning according to the present invention;

3 is a signal configuration diagram showing a configuration of a caption signal according to the present invention.

4 is a diagram showing a data packet structure of caption data according to the present invention;

5 is a view for explaining a control code according to the present invention.

6 is a Hangul complete code table for explaining the configuration of the character code according to the present invention.

7 is a flowchart illustrating a subchannel language discrimination display method according to the present invention.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a language discrimination display method of a viewer-selective caption signal. In particular, the language discrimination of a viewer-selective caption signal that can be displayed when the language of the subchannel character information contained in an even field of a television signal is not a registered language. It relates to a display method.

The closed captioning method in television broadcasting includes an open caption method for superimposing news or notifications by the broadcaster's selection without supervising the viewer by superimposing a caption signal on the active section of the television signal, and a non-active section of the television signal. In other words, when a caption signal is transmitted in a vertical blanking section, there is a closed caption method in which a television screen and dialogue contents can be viewed as captions by a viewer's selection.

Closed captioning closed captioning has been implemented since 1978 in the United States for the hearing-impaired without the sign language, and is also very useful for foreign language learning.

U.S. Patent UPS 5,294,982, published in March 1994, discloses a closed caption broadcasting method of Roman letters and syllable characters. In particular, the captioning method of Korean is explained in detail. In the invention of the U.S. patent, in order to broadcast Korean in a closed caption method, a Korean character is divided into each phoneme of a consonant, a neutral, and a consonant, and an ASCII code corresponding to each phoneme is transmitted. Korean characters are displayed by mapping neutrality and finality.

Since the conventional Korean closed caption method uses at least 2 to 3 bytes to represent a Korean character, the transmission speed and display speed are slow, and the decoding process is required to find the position of one character by combining 3 to 4 bytes in the decoding process. There was a problem that the processing was complicated. The complexity of the decoding process raises the cost of the decoder. This causes a problem of increasing the cost of the decoder, which millions of viewers have to pay in comparison to the encoder that is required only by broadcasting stations.

In addition, simultaneous display of Chinese characters, Korean, Japanese, and English, Russian, and Greek was impossible, and special symbols could not be displayed.

In addition, since the control code is required to display the dialogue information in the middle of displaying the supplementary information and display the supplementary information again, there is no independence between the dialogue information and the supplementary information, and a control system for distinguishing the display mode of the dialogue information is provided. If the display mode control code is not received at the time when the receiver starts to operate, the metabolic information cannot be displayed until the next control code is received.

In addition, the above-mentioned invention was developed based on the television transmission environment of the United States, that is, the geographical environment with a lot of flat land. Therefore, in the geographical environment of Korea where the mountain area is 70% or more, the reception state of the receiver is poor and the quality of the caption display is pointed out. It is becoming.

SUMMARY OF THE INVENTION An object of the present invention is to provide a subchannel language discrimination display method of a viewer-selective subtitle signal that can display the above-mentioned sub-channel subtitle signal, particularly when the language is not a registered language. There is.

In order to achieve the above object, the language discrimination display method of the present invention is a method for receiving a viewer-selective closed caption broadcast in which a caption signal is transmitted on one scanning line for every field of the television signal. Detecting and detecting an even field; Detecting the presence or absence of a caption signal on the detected field; Checking whether it is a control code or a character code by caption data extracted from the caption signal; In the case of the character code, determining the character code value of the caption data to determine whether it is a registered language; And displaying a non-registered language on the screen if it is not a registered language.

Hereinafter, with reference to the accompanying drawings will be described in more detail the present invention.

1 shows a configuration of a television broadcasting apparatus having a viewer-selectable closed captioning function. The audio signal input through the microphone 10 is mixed and amplified by the voice signal processor 30 and transmitted to the television signal modulator 50.

The video signal input through the video camera 20 is amplified and edited by the video signal processor 40 and transmitted to the television signal modulator 50. The television signal modulator 50 modulates the transmitted audio signal by FM, modulates the video signal by AM-modulation of the residual side wave method, and frequency-multiplexes and shifts the AM modulated signal and the FM modulated signal. The high frequency output unit 60 amplifies a high frequency signal and transmits a television signal to the air through an antenna.

In the subtitle encoding unit 70, the text information input unit 71 receives additional information such as dialogue information or urgent news or delivery information related to the television screen. Various control information for caption control is input through the control signal input unit 72. The character information input unit 71 includes a keyboard for inputting characters such as Korean, English, Chinese characters, Japanese, and special characters, and outputs the input character information as a two-byte Hangul completion code KSC5901. The control information input unit 72 includes keypads such as a mode selection key and a function selection key and outputs the input control information as a 7-bit binary code.

The character code generator 73 replaces the MSB of each byte of the input two-byte character code with '0' in case of additional information using the subtitle / additional information flag and adds a parity bit to each byte. To generate a data packet of a total of 18 bits of character code.

The control code generator 74 divides the input 7-bit binary into the upper 4 bits, lower 3 bits, and adds a parity bit for the upper 4 bits, a control code identification bit for 2 bits, and a dialogue / addition flag to generate an upper byte. A lower byte is generated by adding a first parity bit, a second parity bit, a control code identification bit of two bits, and a subtitle subtitle / additional information flag for the lower three bits. A parity bit is added to each generated byte to generate a data packet having a total of 18 bits of control code. Details of the above-described data packet will be described later.

The data packet modulator 75 modulates the data packet generated by the character code generator 73 or the control code generator 74 by a digital modulation method.

The sync counter 76 inputs the sync signal provided from the video signal processor 40, resets it by the vertical sync signal, counts the horizontal sync signal, selects the 262th scan line in the odd field, and the 525th scan line in the even field. Will count the selection. The window signal generator 77 inputs the count value of the sync counter 76 to generate a window signal. The window signal is a drive signal for switching the switching means 78 in order to superimpose the caption signal on a predetermined specific line of the video signal output from the video signal processor 40, for example, 262 and 525 scan lines. Here, it is also possible to transmit dual subtitles by carrying a second language such as English on an odd field, which is a main channel, with Korean characters, and a second language, such as English, on an even field, which is a subchannel.

Referring to FIG. 2, there is shown a configuration of a television receiver for receiving viewer-selective caption broadcasting.

The tuner 110 demodulates a television signal of a channel selected from the high frequency signals received by the antenna and outputs a voice signal and a video signal. The voice signal is transmitted to the voice signal processor 120 to be equalized and amplified and output as voice through the speaker 130. The video signal is transmitted to the video signal processor 140, processed for luminance and color, and then output as an RGB signal. The RGB signal is transmitted to the display driver 160 through the mixer 150, and the display driver 160 drives the CRT 170 in response to the transferred RGB signal to display a television screen on the screen.

The caption decoding unit 200 digitally converts the video signal through the A / D converter 210 and transmits the digital signal to the caption processing unit 230. In addition, the sync separator 220 separates the sync signal from the video signal and transmits the vertical and horizontal sync signals to the subtitle processor.

The caption processor 230 generates a clock signal synchronized with the color burst signal of the video signal processor 140 to extract the caption data packet from the digital signal. Decode the extracted data packet to control the subtitle processing in response to the decoded control code, and read the character data from the font ROM 240 in response to the decoded character code to display the Hangul characters corresponding to the main channel. It is stored in the first page of and the English letter corresponding to the subchannel is saved in the second page. Character data stored in the display RAM 250 is converted into an RGB signal and transmitted to the mixer 150. The caption processing unit 230 exchanges control data with the system control unit 180 of the set. The system controller 180 transmits a caption-related command input through the command input unit 19 to the caption processing unit 180 and controls the system in response to the control data transmitted from the caption processing unit 180.

The detailed configuration of the caption information intended to be used in the caption broadcasting transmission / reception system described above is as follows.

In Korea, M-NTSC TV signals with 525 lines and 60 fields / sec are used as broadcast signals, and the vertical blanking period is specified from scan line 10 to scan line 20.

There are no standards set by the Ministry of Information and Communication on the use of signals in the vertical blanking period. For reference, ITU-R Recommendation Rec 473-2 and US FCC Report and Order 83-120.

The caption signal may use one of the scan lines 10-20 or the scan line 21 or the scan line 262 in the vertical blanking period for transmitting the caption data. One or more may be used for increased data transfer or for other purposes. However, full-field data transmission is not considered in closed captioning.

The transmission bit rate of closed caption data should be 447443.125bps ± 125bps and the maximum long-term rate of change should be within ± 196 (0.0125bps). 10 Hz), which must be frequency synchronized to the color burst. It is preferable that the color carrier carrier has a continuous phase between the scan line and the scan line. If the phase of the color carrier is discontinuous due to screen editing, etc., at least phase synchronization should be performed on the color burst of the scan line.

In the data modulation method, the one corresponding to the logic value '1' is represented by one period of sinusoidal wave having a phase of 0 degrees and fac / 8 (447.443 kHz), and the phase corresponding to the logic value '0' is 180 degrees. It uses a digital modulation scheme called Binary Phase Shift Keying (BPSK) or Phase Reversal Keying (PRK), which is represented by a period of sinusoids with a frequency of fac / 8 (447.443 kHz). The maximum range of phase jitter is ± 10 degrees. The optimal signal waveform will be defined in the future as it may vary depending on the frequency spectrum characteristics of the TV channel. However, due to the fundamental band-limiting frequency, the BPSK waveform may experience severe distortion where logic transitions occur, so that the phase-corrected waveform can be used for broadcasting after passing through a second-order Butterworth filter with a cutoff frequency of 3.5 MHz. Shall be. The impulse response of the Butterworth filter used is

The inspection method and basis are defined in item I-7 (TV broadcasting station) item 4 (text multicasting) b) (superposition position of data line and amplitude of text signal) among inspection items of radio station, and the waveform of caption signal is not NRZ. Since it is a pure sinusoidal wave, it is not necessary to apply the above criteria. However, in order to expand the coverage area, which is 70% or more like Korea, the maximum sinusoidal wave is 90 ± 5 IRE. Although the maximum amplitude of the normal data signal is defined, the overshoot may be included in the filter passband characteristic, so the maximum value of the overshoot is 5 IRE.

Referring to FIG. 3, the caption signal data line includes a six-cycle bit clock synchronization signal 302, a weed start signal 304, and an 18-bit data string 306.

The bit clock synchronizing signal 302 is a sinusoidal signal of 6 cycles and can be used to extract the signal from the caption decoding unit and read out the bit period of 18-bit data. The frequency is fac / 4 (894.886 kHz). If the phase of the color carrier of the scan line is 0 degrees, it starts at the point 9.5usec (34 bursts of color burst) from the falling edge (OH) of the horizontal synchronization signal, and the phase of the color carrier of the scan line is If it is 180 degrees, it starts at the point of 9.64usec (34.5 cycles of color burst) from the falling edge (OH) of the horizontal synchronization signal. Since this signal is in frequency synchronization with the color burst of the corresponding line, it is also possible to extract the bit clock synchronization signal from the color burst.

The word start signal 304 is a period of a sine wave signal of fac / 16 (223.722 kHz) and a phase of 180 degrees, which serves to indicate the start of an 18-bit data packet.

The data string 306 is composed of 18 bits, and the bit rate is fas / 8 (447.443 kHz) and is modulated by the BPSK method.

Referring to FIG. 4, the data packet is composed of three parts: a parity p, a subtitle subtitle / additional information flag C / T, and a code value. D0 to D8 are the lower words, and D9 to D17 are referred to as the words. D17 represents even parity for D0 to D16. This parity bit is for first detecting errors in transmission. D7 and D16 are the subtitle caption / additional information flag, 0 for the subtitle and 1 for the additional information, and the values of D7 and D16 must match. This flag is used to maintain word priority. D0 to D6 and D9 to D15 together represent a code value. Code values are interpreted as control codes if D5, D6, D14, and D15 are mode 0, and as character codes otherwise.

Referring to FIG. 5, D1, D2, D3, D9, D10, D11, and D12 of the control code are control code data bits, and D0, D4, D8, and D13 are parity for the control code data bits. The three-bit code value of the lower word designates five functions. The five functions consist of a color designation function, a character attribute and rollup function, a display method and a rolldown function, a position shift function, and a matrix position designation function. In addition, the 4-bit code value of the upper word of the control code specifies 16 sub-functions of each function. Here, parity for D1, D2, D3, and D4, D4 is parity for D1, D2, D10, and D11, and D13 is parity for D9, D10, D11, and D12.

In addition, the control code is transmitted twice in succession for safe reception of data, and the horizontal / vertical writing code and the matrix positioning code are transmitted almost every four seconds. Detailed description of the control code will be described later.

Referring to FIG. 6, the character code represents the data bits of the KSC5601 code with D0 to D6 of the lower word and D9 to D15 of the upper word. D8 is even parity for D0 to D7.

In the present invention, since the ASCII code is not used at all, the seven bits of D0 to D6 correspond to seven bits except for the MSB among the lower bytes of KSC5601, and the upper bytes correspond to seven bits except for the MSB.

Among the Hangul complete code (KSC5601) shown in FIG. 6, lines A1 to A2 (special characters), lines A3 (English), lines A4 (support), lines A5 (Greek), lines AA to AB (Kana, Japan), AC It is limited to lines (Russian), lines B0 to C8 (Korean), and lines CA to FD (Chinese). The character code is sent only once per character.

The Korean subtitle can be transmitted using any scan line per field as described above. One or more transmission scan lines defined in the field are called channels. Since NTSC TV has two fields in interlaced scanning, two channels may be used. In other words, it is possible to use two-language dialogue subtitles, such as voice multiplexing. Among them, the Korean-only dialogue subtitles should use an odd field channel and other foreign language-only dialogue subtitles should use an even field channel. Control codes transmitted for each channel are the same code set, and all character codes are included in KSC9501.

There are two kinds of information transmitted through the subtitle channel, and the method of interpreting and displaying the control code varies according to the type. One of the two types is the subtitles related to the video signal being broadcast, and the other is additional information which is not related to the broadcasting content displayed on the screen.

If the values of the subtitle subtitles / additional information flags are both '0' in the LSWord of the data packet structure, the code value is interpreted for display of the subtitle subtitles, whether the control code or the character code. In this case, only a part of the broadcasted screen is covered and the dialogue corresponding to the audio signal is displayed in the subtitle form.

Only two or five lines of subtitles are used at the same time, and scrolling, erasing, and rewriting are used to display the dialogue.

When only one channel is transmitted, characters from various countries may be mixed or used exclusively for Korean or foreign languages. When two channels are transmitted, each channel may be divided into a Korean channel and a foreign language channel.

This subtitle subtitle should be as consistent with the voice information as possible, and therefore has a higher priority than the additional information in channel occupancy in two word units.

If the values of the subtitle subtitles / additional information flags are both '1' in LSWord and MSWord of the data packet structure, the code value is interpreted for display of additional information, whether the code value is a control code or a character code. The additional information display displays character information on the entire screen as in computer communication regardless of the broadcast contents. Do not use scroll function because it is displayed in full screen.

When the information is transmitted through the two channels, the additional information does not need to be separated like the meta information. The additional information may occupy the channel at any time when the information is not displayed on the channel. You can pass it and finish captioning before the channel can be seized again.

The control code consists of two 9-bit words. LSWord contains D1, D2, and D3 bits for classifying functions. MSWord contains D9, D10, D11, and D12 bits for selecting one of the classified functions. Included.

Control codes are classified into color designation, attribute designation, display control, scrolling, cursor movement, action value and column positioning control code according to their function.

The color designation control code is a control code transmitted to change the foreground and background colors of the transmitted character data. Therefore, if you want to change the foreground and background of the character to be transmitted, you can send the character after transmitting the color specification code. The receiver sets the foreground and background colors by the most recently received color control code. In addition, the color of the foreground and background can be changed simultaneously or independently. Colors are black, red, magente, blue, cyan, green, yellow and white, and the background color is transparent. The video of the program should be shown in the remaining parts of the display cell except for characters. Each character must be outlined with a different color than the text.

The character attribute control code is a control code transmitted to change the attribute of character data. Therefore, to change the attribute of the character to be transmitted, send the character code after sending the attribute designation control code first. You can specify Normal, Underline, Blinking, and Reversed. Underlining, Blinking, and Reversed operate independently, so all of these sequels can be applied at once.

The function of each attribute designation control code is as follows.

▷ Underline: Underline it to display just below each character to be displayed.

▷ Blinking: The character to be displayed blinks. The previously displayed part does not blink, the later displayed part blinks, and the blink period varies depending on the receiver implementation.

▷ Reversed: The foreground and background colors currently used by the receiver are swapped.

▷ Normal: Displays the character as the default attribute by resetting all the attributes already specified.

Display method The control code is a control code transmitted to control the screen display method. The display code, screen erase, receive storage, horizontal writing, and vertical writing can be designated.

▷ Display: Display received problem data on the screen immediately (in Roll-up, Roll-down) or display the data saved by 'receive save' control code on the screen (when pop on).

▷ Save Receive: Save received character and control code until screen display.

▷ Horizontal writing: When displaying the character code that is received continuously on the screen without intervention of the position control code, move the next character position to the right of the current character.

▷ Vertical writing: When displaying the character code that is received continuously on the screen without intervention of the position change control code, move the next character position to the bottom of the current character.

The scroll control code is a control code for scrolling the screen by setting a certain portion of the subtitle area, and the scroll control codes include '2-5 line roll-up' and '2-5 line roll-down'.

▷ 2 ~ 5 lines Roll-up: Control code for scrolling the window contents up one line in the window consisting of 2 ~ 5 lines in the upward direction including the current character display position (cursor position). The top of the lines disappears with scrolling and the bottom is replaced with the most recently decoded characters. This control code eliminates the need for a separate APDR code, and removes all characters outside the specified window.

▷ 2 ~ 5 lines Roll-down: Control code for scrolling the window contents down one line in the window consisting of 2 ~ 5 lines in the downward direction including the current character display position (cursor position). Of the rows of, the bottom row disappears with scrolling and the top row is replaced with the most recently decoded characters. When using this control code, no separate APUR code is required, and all characters outside the designated window are deleted from the screen.

The position movement control code is a control code relating to the direction movement of a position to display a character.

▷ APF (Active Position forword): In case of horizontal writing, it moves to half width (1 width of English alphabet) in the main direction of writing (right). When writing vertically, the height of Hangul kanji moves in the main direction (bottom).

▷ APB (Active Positionackward): When writing horizontally, move the width of 1 Korean character (1 English alphabet width) in the opposite direction (left) of main writing. In case of vertical writing, the height of Hangul kanji moves in the opposite direction (upward).

▷ APDR (Active Position Down Return): When writing horizontally, move to the leftmost character position (first column position) of the line just below the current character display position. In case of vertical writing, it moves to the position of the top letter of the immediately left column of the current character display position (the first row position). Moves the Hangul Hanja height in the main direction (bottom).

▷ APUR (Active Position Up Return): When writing horizontally, move to the leftmost character position (first column position) of the line immediately above the current character display position. In case of vertical writing, it moves to the top position of the right column of the current character display position (the first row position).

▷ 3 ~ 6 letters APF: When writing horizontally, APF should be 3 ~ 6 letters wide. In case of vertical writing, APF is executed as high as 3 ~ 6 letters.

The exception of position movement control is as follows. That is, in case of horizontal writing, when the character is displayed up to the rightmost character position (column position 18) of the line, it moves the appropriate position such as APDR, APUR, APB, 2-5 line roll-up, 2-5 line roll-down If a character code is received without an associated control code, the character is displayed by moving to the leftmost character position (first column position) of the line without changing the line. However, if the character code at this time is a space code, it should be ignored until a character code other than a space code is received. In case of vertical writing, when characters are displayed up to the bottom letter position (10th row position) of the column, control related to proper position movement such as APDR, APUR, APB, 2-5 line roll-up, 2-5 line roll-down If a character code is received without a code, the character is moved to the top letter position (first line position) of the column without changing the column to display the character. However, if the character code at this time is a space code, it should be ignored until a character code other than a space code is received.

Transmission of control code according to screen display method is as follows.

The order of control code transmission during pop-on is reception storage + (other control code) + character string + (other control code) +… + Clear Screen + Show Screen + Receive Save + (Other Control Code) + String + (Other Control Code) +… + Freeze + show screen +… Follow the order. In order for the receiver to properly view the character information currently displayed in the pop-on method, a proper delay time is necessary before the transmitter sends the screen erasure control code.

Control code transmission sequence during roll-up is screen display + (other control code) + string + (other control code) + string + (2 ~ 5 lines roll-up) + screen display + (other control code) + string + (Other Control Code) + String + (2 ~ 5 Line Roll-up) +… Follow the order. Whenever 2 ~ 5 lines of roll-up control code is received, the outside area of the window should be cleared.

Control code transmission sequence during roll-down screen display + (other control code) + string + (other control code) + string + (2 ~ 5 lines roll-down) + screen display + (other control code) + string + (Other Control Code) + String + (2 ~ 5 Line Roll-down) +… Follow the order. Each time a 2-5 line roll-down control code is received, the outer area of the window must be cleared.

The control code for vertical writing is as follows.

When the receiver decodes the vertical writing control code, the moving direction of the Hangul characters displayed on the screen is changed to the column direction.

Vertical writing is mainly used when subtitles already exist in the broadcast contents. The structure of the character cell during vertical writing does not have to be the same as the character cell for each character during horizontal writing.

When no special position control code is received during vertical writing, the default position of the receiver is determined as the first character position in column 16.

In case of vertical writing, the direction of active position of cursor movement control codes (APDR, APUR, APF, APB, n-APF) is determined based on the vertical column. That is, Down = Left, Up = Right, Forward = Down, and Backward = Up. APDR is defined as a control code for 'going to the rightmost column position (first row position)' and APUR is 'controlling to move to the rightmost column position (first row position) right column' Is defined as

When writing vertically, 2 ~ 5 lines Roll-up displays the window contents by scrolling one column to the right of the screen inside the window consisting of 2 to 5 right vertical columns including the current character display position (cursor position). As the control code for, the rightmost column of the tasks inside the selected window disappears with scrolling and the leftmost column is replaced with the most recently decoded string. This control code eliminates the need for a separate APDR code to move to the top left column for vertical writing. All areas outside the 2 to 5 windows are cleared. 2 ~ 5 lines in vertical writing Roll-down scrolls the window contents by one column to the left of the screen inside a window composed of 2 to 5 left columns, including the current character display position (cursor position). As a control code, the leftmost column among the columns in the selected window disappears with scrolling and the rightmost column is replaced with the most recently decoded characters. This control code eliminates the need for a separate APUR code (moving to the top right column for vertical writing). All areas outside the 2 to 5 windows are cleared.

Ignore vertical writing because it is intended for use with lower captions, such as news. Ignore the 'three to five row roll-up' and the 'three to five row roll down'.

Valid code identification and processing are as follows.

The procedure and processing for deciding a valid code by decoding a caption signal at a receiver are as follows.

① It is judged as valid code only when D7 and D16 are same.

② D17 and D0 D1 D2 D3 D4 D5 D6 D7 D8 D9 D10 D11 D12 D13 D14 D15 If D16 is the same and all are the same, a valid code is determined.

(3) If D5 and D6 are each (0,0) and D14 and D15 are each (0,0), the control code is determined.

If D5, D6 is (0,1) or (1,0) or (1,1), respectively, and D14, D15 is (0,1) or (1,0) or (1,1), respectively, the character code Determined.

If any one of D5, D6 and D14, D15 is (0,0) and the other is (0,1) or (1,0) or (1,1), the control code and the character code are simultaneously received. There is no case, so this code is determined to be an error.

④ D8 and D0 are determined by the character code from the above ③. D1 D2 D3 D4 D5 D6 Check if D7 is the same and if it is different, it is determined as an error.

⑤ If it is determined in ④ above that there is no error Check if the character code is defined in KSC5601. If the code is not defined, '?' or If it is a defined code, the corresponding character is displayed on the screen.

⑥ When the control code is identified in No. ③ above, D0 and D1 in LSWord D2 D3 D9 matches and D4 and D1 D2 D11 If D12 is matched, at least one is found to be an error.

⑦ If it is determined that it is not an error in No. ⑥ above, check if it is defined in the control code table of Fig. 5 and if it is not defined, it is judged as an error and if it is a defined control code,

⑦ If the control code defined in the control cone table in No. ⑥ above, the same LSWord and MSWord are waiting for repeated transmission.

⑧ If the same LSWord and MSWord are transmitted repeatedly, the control code is applied.

The above-mentioned valid code discrimination and processing show the most preferable embodiment and similarly, the modification is possible. For example, different combinations of parity of control codes may be mentioned. In particular, various methods may be employed to prevent errors in the control code.

The effects of the present invention described as described above will be described as follows.

Referring to FIG. 7, the caption processing unit of the receiving apparatus which receives the caption signal having the character data in the main channel and the subchannel first detects the odd field and the even field by the synchronization signal (1000) and if the even field is the caption signal. (1002) Then, it is checked whether it is a control code or a text signal (1004). If it is a text signal, it is classified as a subchannel signal. In the case of the subchannel signal, the character code value is discriminated based on the KSC5601 Korean completion code value. When the code value of the upper byte is equal to any one of a3, a4, or b0 to c9, ca to fd, a5, aa, ab, and ac, as shown in the code table of FIG. 6 (1006) In operation 1010, the controller 110 determines that the language is an unregistered language and displays the language that is not registered on the screen (1010). If the language is registered in step 1008, the language is displayed on the screen (1012).

As described above, in the present invention, whether the subtitle data received in the subchannel according to the KSC 5601 code value is one of Korean, English, Japanese, Chinese, Greek, and Russian. You can make your viewers aware of this.

Claims (2)

CLAIMS 1. A method for receiving a viewer-selective closed caption broadcasting in which a caption signal is carried on one scanning line for each field of a television signal and transmitted, the method comprising: detecting an even field by detecting a vertical synchronization signal of a received television signal; Detecting the presence or absence of a caption signal on the detected field; Checking whether it is a control code or a character code by caption data extracted from the caption signal; In the case of the character code, determining the character code value of the caption data to determine whether it is a registered language; And displaying a non-registered language on the screen if the registered language is not a registered language. The method of claim 1, wherein the displaying of the language discrimination comprises determining and displaying, in an unregistered language, a case not belonging to any one of Korean, English, Greek, Japanese, Chinese, and Russian based on a higher byte value of a KSC5601 Korean complete code value. A subchannel language discriminating display method of a viewer-selectable subtitle signal.