Patent Publication Number: US-RE37501-E

Title: Apparatus and method for displaying caption broadcast and teletext on the screen of a double-wide television

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an apparatus and method for displaying a caption broadcast and teletext on the screen of a double-wide television, and more particularly, to an apparatus and method for displaying a caption broadcast and teletext on the screen of a double-wide television in which a televised picture can be displayed concurrently with a separate caption broadcast picture or teletext picture. 
     2. Description of Prior Art 
     When using a conventional television including a remote controller having a key panel which incorporates a caption button, if the caption button is selected by a user while a broadcast including caption and teletext signals is being received, caption information will be displayed over a televised picture. Also, if the key panel of the remote controller includes a teletext button which is selected by a user, a blanking-processed teletext signal block will be displayed over the televised picture. 
     Thus, when viewing a current broadcast having caption and teletext signals on a conventional television, the caption broadcast picture of teletext picture will overlap the televised picture, so that the televised picture is partially obscured. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide an apparatus and method for displaying a caption broadcast and teletext on the screen of a double-wide television in which a televised picture can be displayed concurrently with the caption broadcast or teletext picture without their being any overlap between the pictures. 
     According to one embodiment of the invention, there is provided an apparatus for displaying a caption broadcast and teletext on the wide screen of a double-wide television. The apparatus separates first and second broadcast signals including a video signal and caption and teletext signals into luminance (Y) and chrominance (C) signals using first and second comb filters which output said first and second broadcast signals. The apparatus includes a signal separating circuit for separating a second video signal output from the second comb filter into a first picture signal and caption and teletext signals. 
     The apparatus also includes a switching circuit for selectively outputting a first video signal output from the first comb filter and the caption and teletext signals output from the signal separating circuit. Additionally, a double-picture processing circuit is included in the apparatus for processing the first picture signal output by the signal separation circuit and the caption and teletext signals output from the switching circuit so that pictures corresponding to the first picture signal and the caption and teletext signals can be displayed on corresponding left and right portions of the wide screen, respectively. 
     A controller is also included in the apparatus for controlling the signal separating circuit to separate the second video signal into the first picture signal and the caption and teletext signals according to a key input, controlling the switching circuit to selectively output the first video signal output from the first comb filter and the caption and teletext signals output from the signal separating circuit and controlling the double-picture processing circuit. A matrix circuit included in the apparatus converts a third video signal output from the double-picture processing circuit having first and second luminance and chrominance components, into a fourth video signal having RGB components. A CRT driver circuit is also included in the apparatus for driving a CRT using the fourth video signal having RGB components. 
     According to another embodiment of the invention there is provided a method for displaying a caption broadcast and teletext on the wide screen of a double-wide television. The method comprises the steps of displaying a picture corresponding to a broadcast signal including caption and teletext signals on the wide screen of a double-wide television and segmenting the wide-screen into at least two distinct portions if it is determined that a caption key is selected so that a caption display mode is initiated. 
     The method also includes the step of displaying a televised picture in one of the at least two distinct portions and a picture corresponding to the caption broadcast signal in another one of the at least two distinct portions segmented in the segmenting step. 
     According to another aspect of the present invention, the method may also include the step of converting the caption display mode into a teletext display mode if the caption key is selected during the step of displaying a televised picture in one of the at least two portions so that a picture corresponding to the teletext signal is displayed in the another one of the at least two distinct portions. 
     According to yet another aspect of the present invention, the method may also include the step of displaying a picture corresponding to a broadcast signal if the caption key is selected when the picture corresponding to the teletext signal is displayed in the another one of the at least two distinct portions. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The above objects and advantages of the present invention will become more apparent by describing in detail a preferred embodiment thereof with reference to the attached drawings in which: 
     FIG. 1 is a block diagram of an apparatus for displaying a caption broadcast and teletext on the wide screen of a double-wide television according to one embodiment of the present invention; and 
     FIG. 2 is a flowchart illustrating a method for displaying a caption broadcast and teletext on the screen of a double-wide television according to another embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In FIG. 1, an exemplary apparatus for displaying a caption broadcast and teletext on the screen of a double-wide television according to one embodiment of the present invention includes a television signal receiver  20 , an audio signal processor  70 , left (L) and right (R) speakers  72  and  74 , a microcomputer  71 , a video signal processor  30 , a matrix portion  40 , a cathode-ray tube (CRT) driver  50  and a CRT  60 . 
     The television signal receiver  20  includes first and second tuners  21  and  22  for converting a carrier wave introduced via an antenna  10  into an intermediate-frequency signal, and first and second demodulators  23  and  24  for demodulating video and audio signals from the intermediate-frequency signal. The audio signal processor  70  processes the audio signal output from the first and second demodulators  23  and  24  and then outputs the result to left and right channels. The left (L) and right (R) speakers  72  and  74  are driven by the audio signal and the microcomputer  71  outputs control signals CNT 1 , CNT 2  and CNT 3  in accordance with the input of a key input circuit or portion  72 . 
     The video signal processor  30  includes first and second comb filters  31  and  32  for separating first and second video signals output from the first and second demodulators  23  and  24  into luminance (Y) and the chrominance (C) signals, a signal separating circuit or portion  34  for separating the luminance (Y) and chrominance (C) signals output from the second comb filter  32  into a right picture signal (d) and caption and teletext signals (e) in accordance with the control signal CNT 3  generated by the microcomputer  71 , a switch SW 1  for selectively outputting the luminance (Y) and the chrominance (C) signals output from the first comb filter  31  and the caption and teletext signals (e) output from the signal separating circuit  34  as a left picture signal according to the control signal CNT 2  of the microcomputer  71 , a double-picture processing circuit  33  for processing the left and right picture signals respectively output from the switch SW 1  and the signal separating circuit  34  into a double-picture. A matrix circuit  40  converts the luminance (Y) and chrominance (C) signals output from the double-picture processing portion  33  into RGB signals, and the CRT driver  50  drives the CRT. 
     FIG. 2 is a flowchart illustrating a method of displaying caption broadcast and teletext on a screen of a double-wide television according to the present invention. 
     As shown in FIG. 2, the method of displaying a caption broadcast and teletext includes the steps of inputting a caption broadcast signal and displaying a picture corresponding to the broadcast signal on a wide screen of a double-wide television (step  80 ), and selecting a caption key (first caption key selecting step  81 ). 
     The method also includes the steps of segmenting a wide-screen into at least two separate portions capable of displaying at least two distinct pictures so that a caption display mode is initiated (step  82 ), displaying a televised signal and a caption signal in right and left screens (step  83 ), respectively, selecting the caption key again (second caption key selecting step  84 ), and converting the caption display mode into the teletext display mode so that a picture corresponding to the teletext signal is displayed on another one of the at least two distinct portions of the wide-screen (step  85 ). The method also includes the step of selecting the caption key for returning the double-picture mode to the initial wide-picture mode (third caption key selecting step  86 ). 
     Hereinafter, a preferred embodiment of the present invention will be described with reference to FIGS. 1 and 2. 
     A double-wide television is provided according to a preferred embodiment of the present invention for displaying a video signal on a wide-screen (16:9 aspect ratio) and for simultaneously displaying two image signals introduced from each different signal source on left and right portions of the screens which are formed by dividing the wide-screen. 
     As shown in FIG. 1, in the television signal receiver  20 , the first and second tuners  21  and  22  generate intermediate-frequency signals from a carrier wave introduced via the antenna  10 , and the first and second demodulators  23  and  24  receives the intermediate-frequency signals generated from the first and second tuners  21  and  22  to generate first and second video signals and the audio signals for the left and right channels. The audio signals of the left and right channels output from the first and second demodulators  23  and  24  are reproduced as an audio signal having various modes by the audio signal processor  70 . Subsequently, the audio signals are output as sound waves via the left (L) and right (R) speakers  72  and  74 . 
     The first and second video signals respectively output from the first and second demodulators  23  and  24  are input to the video signal processor  30  in which the first and second video signals are processed so as to be displayed as two corresponding pictures in separate portions of the wide-screen. Here, the first and second video signals include the caption and teletext signals. 
     In the video signal processor  30 , in order to simultaneously display pictures corresponding to two video signals on left and right portions of the wide-screen in a double-picture mode, the horizontal and vertical scanning periods of each video signal before being coupled to each other and the horizontal and the vertical scanning periods of the coupled video signal should be matched. Here, it is assumed that the horizontal and vertical scanning periods of the two video signals being coupled to each other are the same. 
     The video signals output from the first and second demodulators  23  and  24  are input to the first and second comb filters  31  and  32  in order to be output as left and right picture signals which each are separated into luminance (Y) and the chrominance (C) signals. 
     Also, the audio signals output from the first and second demodulators  23  and  24  are processed by the audio signal processor  70  and then output to the left and right channel speakers. Then, the audio signals are output as sound waves via the left (L) and right (R) speakers  72  and  74 . 
     On the other hand, a first video signal (f) having the luminance (Y) and the chrominance (C) components output from the first comb filter  31  is output as the left picture signal via contact points a and c of the switch SW 1 . 
     A second video signal output from the second comb filter  32  is input to the signal separating circuit  34  and then output as the right picture signal. Here, when a caption key is selected in a key input device or panel  72 , the microcomputer  71  outputs the control signal CNT 3  to the signal separating portion  34 . Thus, the second video signal output from the second demodulator  24  is separated into a video signal (d) and the caption and teletext signals (e) by the signal separating circuit  34 . 
     The video signal (d) separated by the signal separating circuit  34  is output as a right picture signal, and the caption and teletext signals (e) are output to the contact point b of the switch SW 1 . Also, in the switch SW 1 , the contact point b is connected to the contact point c by the control signal (CNT 2 ) of the microcomputer  71  to output the caption and teletext signals (e) output from the signal separating circuit  34  as a left picture signal. 
     The left and right picture signals output from the switch SW 1  and the signal separating portion  34  are processed by the double-picture processing circuit  33  according to the control signal CNT 1  of the microcomputer  71 , and then the double-picture processing circuit  33  outputs the double-picture signal having the luminance (Y) and chrominance (C) signals. 
     Subsequently, matrix-processing is performed with respect to the luminance (Y) and the chrominance (C) signals output from the double-picture processing circuit  33  in the matrix circuit  40  which outputs RGB signals. The CRT driver  50  receives the RGB signals and drives a CRT  60  to display an image including the two separate pictures on right and left portions of the wide screen. 
     Next, the method for display a caption broadcast and teletext on separate portions of the wide screen of a double-wide television will be described with reference to FIG.  2 . 
     As shown in FIG. 2, a video signal of a broadcast channel, including a caption signal, is input to the double-wide television to be displayed on a wide-screen (step  80 ). Subsequently, the microcomputer  71  determines whether a caption key of the key input device or panel  72  is selected by scanning the output of the key input device or panel  72  which reflects different key strokes input by a user (step  81 ). 
     If the caption key is selected, the microcomputer  71  outputs the control signal CNT 1  to the double-picture processing circuit  33  to convert a single wide screen of the double-wide television into two distinct portions so that two pictures may be displayed without any overlap (step  82 ). 
     After the single screen is converted into two distinct portions the switch SW 1  is switched to the contact point b by a control signal CNT 2  generated by the microcomputer  71  and the signal (f) output from the first comb filter  31  is blocked. Also, the caption signal (e) output from the signal separating circuit  34  is output as the left picture signal and the video signal (d) from which the caption signal is eliminated is output as the right picture signal. As a result, the video signal (d) is displayed on the right portion of the wide screen and the caption information signal is displayed in the left portion of the wide-screen (step  83 ). 
     However, one of ordinary skill in the art will appreciate that the video signal (d) may be displayed on the right portion of the wide screen and the caption information signal displayed on the left portion thereof. Subsequently, the microcomputer  71  scans the keys to determine whether the caption key has been selected a second time (step  84 ). The caption key is selected a second time if the image signal includes a teletext signal. As a result, the caption display mode is converted into the teletext display mode in the signal separating circuit  34  so that a picture corresponding to the teletext signal can be displayed in the left portion of the wide-screen. 
     Next, the microcomputer  71  determines whether the caption key has been selected a third time by scanning the output of the key input device  72  (step  86 ). If the caption key is selected, the microcomputer  7  removes the caption or teletext picture displayed in the left portion of the wide-screen and restores the original wide screen by generating the control signal CNT 2  again. Thus, a picture corresponding to a video signal of a broadcast channel including a caption signal may be displayed, as per step  80  described above. 
     By employing the apparatus and method of displaying a caption broadcast and teletext of the present invention, the televised picture and the caption broadcast or teletext picture can be displayed in two separate portions of the wide-screen of a double-wide television so that the pictures do not overlap each other.