Television – Format – Including additional information
Reexamination Certificate
1997-05-05
2001-09-25
Peng, John K. (Department: 2714)
Television
Format
Including additional information
C348S484000, C348S468000, C348S473000, C348S589000
Reexamination Certificate
active
06295093
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a closed-caption broadcasting and receiving method and apparatus thereof, and more particularly, to a closed-caption broadcasting and receiving method and the apparatus thereof, whereby character and control codes are encoded in a television signal to be transmitted as a caption broadcasting signal, and then received to be displayed on a screen of a television receiver by selection of a viewer.
2. Description of the Related Art
The caption broadcasting system in television broadcasting can be classified into an open caption system for displaying a caption of emergency news, announcements, etc., on a television screen by selection of a broadcaster by superimposing the caption signal in an active period of a television signal, and a closed caption system for displaying a caption of words on the screen by selection of a viewer by encoding the caption signal in a non-active period, i.e., in a vertical blanking interval of the television signal.
The closed-caption broadcasting has been carried out in the United States since 1978 for people who have difficulty in hearing and cannot recognize the words of the scene without sign language. The closed-caption broadcasting is also useful in studying a foreign language.
The U.S. Pat. No. 5,294,982 issued on March, 1994 discloses a closed-caption broadcasting system suitable for displaying Roman characters and syllable characters. Especially, captioning of the syllable characters such as Korean is explained in detail in this patent. According to this patent, in order to broadcast Hangul (Korean alphabet) as a closed-caption, one Hangul character is separated into initial, medial, and final consonant phonemes and ASCII (American Standard Code for Information Interchange) codes corresponding to the respective consonant phonemes are transmitted. In a receiving part, the ASCII codes are received and decoded, and then the initial, medial, and final consonant phonemes are mapped to form and display the Hangul character.
However, according to this conventional Hangul closed-captioning system, since at least two or three bytes of data should be used for representing one Hangul character, the transmission speed and the display speed thereof become lowered. Also, its decoding process becomes complicated because the position of one Hangul character is searched by combination of three or four bytes of data, causing the cost of a caption decoder to increase.
Also, the conventional Hangul closed-captioning system has difficulty in simultaneously displaying Chinese characters, Hangul, and Japanese, and in simultaneously displaying English, Russian and Greek, as well as in displaying special symbols.
Also, since a control code is required in case of displaying word information between additional information and then displaying additional information again, there is no independence between the word information and additional information, and the control system for discriminating a display mode of the word information becomes complicated. If the display mode control code is not received at the start point of the receiving device's operation, the word information cannot be displayed until a next control code is received.
Further, since the conventional system has been developed based on the television broadcasting environment in the United States, it shows an inferior receiving state in the geographic setting of Korea that has mountainous districts over 70%, thereby deteriorating the quality of the caption display.
Meanwhile, related arts regarding the closed-caption broadcasting and receiving apparatuses are disclosed in U.S. Pat. Nos. 5,327,176, 4,310,854, 5,347,365, 5,249,050, 5,374,960, and 5,315,386, and Japanese Patent Laid-open Nos. 6-165065 and 6-165064.
SUMMARY OF THE INVENTION
It is an object of the present invention to solve the problems involved in the prior art, and to provide a viewer's selection type caption broadcasting method especially having an effect on the caption broadcasting of Hangul.
In one aspect of the present invention, there is provided a caption broadcasting method which comprises the steps of inputting character information and control information; producing a control code of two words by combining the control information with a mode control bit and a parity bit, and a character code of two words including a syllable character completion type code by combining the character information with a mode control bit and a parity bit, outputting a digital modulated caption signal by inputting the control code and the character code; and coding the caption signal in at least one line which does not affect a television image signal to transmit the caption signal.
In another aspect of the present invention, there is provided a caption broadcast receiving method which comprises the steps of detecting a sync signal of a received television signal; extracting a caption signal encoded in a last scanning line by counting a horizontal sync signal in response to a detected vertical sync signal; restoring digital data from the extracted caption signal; detecting an error of the restored data; decoding the control code of the data and reading out character data corresponding to a character code from a font ROM (read only memory) wherein the character data based on a syllable character completion type code is stored to store the read-out character data in a display memory; and converting the character data stored in the display memory into a video signal to display the video signal on a display screen.
In still another aspect of the present invention, there is provided a caption broadcasting apparatus for superimposing closed-caption information in a video signal and modulating an audio signal and the video signal to a television signal to transmit in the air the modulated television signal as a high frequency signal, the apparatus comprising character information input means for inputting additional information such as word information related to a television scene, emergency news, announcements, etc., as a 2-byte syllable character completion type code; control information input means for inputting 7-bit control information for reception control of a closed-caption broadcast; character code generating means for generating a data packet of an 18-bit character code by using the MSB (most significant bit) of each byte of the 2-byte syllable character completion type code as a caption word/additional information flag, replacing the MSB by “O” in case of the additional information, and adding a parity bit to each byte; control code generating means for generating a data packet of an 18-bit control code by dividing the 7-bit control information into an upper 4 bits and lower 3 bits, creating an upper byte by adding to the upper 4 bits a parity bit, control code discriminating bits of 2 bits, and a word/addition flag, creating a lower byte by adding to the lower 3 bits a first parity bit, a second parity bit, control code discriminating bits of 2 bits, and a caption word/additional information flag, and adding a parity bit to each of the created word bytes; data packet modulating means for modulating the data packet generated by the character code generating means or the control code generating means by digital modulation to produce a caption signal; synchronous counter means for receiving horizontal and vertical sync signals of the video signal and counting the horizontal sync signal, the synchronous counter means being reset by the vertical sync signal; window signal generating means for receiving a counted value of the synchronous counter means and generating a window signal for selecting a predetermined line of each field; and switching means for selectively switching the video signal and the caption signal in response to the window signal.
In still another aspect of the present invention, there is provided a closed-caption broadcast receiving apparatus for receiving a caption signal from a received composite video signal, the apparatus comprising a dat
Bae Jum-Han
Park Hyun-Jeong
Yang Jin-Hwa
Natnael Paulos M.
Peng John K.
Samsung Electronics Co,. Ltd.
Staas & Halsey , LLP
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