Abstract:
A display apparatus and control method thereof. The display apparatus includes a first processor outputting a on-screen display (OSD) video signal or a processed first video signal including an OSD window; an OSD extractor extracting the OSD window from the OSD video signal; and a second processor mixing an externally inputted second video signal and the OSD window extracted from the OSD extractor, and outputting the mixed signal. A display apparatus is thus provided which generates a uniform OSD window and reduces costs.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application claims priority from Korean Patent Application No. 10-2004-0097686, filed on Nov. 25, 2004 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.  
       BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present invention relates to a display apparatus and a control method thereof, and more particularly, to a display apparatus and a control method thereof in which a process of generating an on-screen display (OSD) is improved.  
         [0004]     2. Description of the Related Art  
         [0005]     Generally, a display apparatus receives a video signal from a video signal source such as a video card, a TV card of a computer, etc., thereby displaying a picture on a screen thereof. Recently, a display apparatus has been released on the market, which displays a picture by receiving a video signal from various external signal sources such as a video tape recorder (VTR), a video camcorder, a set top box (STB) or the like to boost practical uses thereof.  
         [0006]     The display apparatus comprises a processor to process the video signal received into a displayable format. Particularly, the display apparatus requires at least one processor to process various video signals received from various kinds of signal sources. Generally, the processor comprises an OSD block to provide a user with a selection menu through an OSD function.  
         [0007]      FIG. 1  is a control block diagram of a conventional display apparatus. As shown therein, the display apparatus comprises a first processor  10  and a second processor  20 .  
         [0008]     The first processor  10  comprises an OSD generator  12 . The first processor  10  receives a video signal and outputs the video signal to the second processor  20  after processing it.  
         [0009]     The video signal refers to a video signal inputted from a VTR or a digital versatile disk (DVD) player, a standard definition (SD) video signal, or a high definition (HD) video signal. According to the inputted format, such video signals pass through an analog to digital (A/D) converting process or a decoding process to be processed as a displayable signal.  
         [0010]     When an OSD generating signal is received while the first processor  10  processes the video signal inputted thereto, the OSD generator  12  generates an OSD signal. The OSD signal generated by the OSD generator  12  is mixed with the video signal processed by the first processor  10 , and the mixed signal is then inputted to the second processor  20 .  
         [0011]     When the OSD generating signal is received while the second processor  20  processes the video signal inputted thereto, an OSD generator  22  generates an OSD signal. The OSD signal generated by the OSD generator  22  is mixed with the video signal processed by the second processor  20 , and is then outputted to and displayed on a display part (not shown). The video signal transmitted from the first processor  10  to the second processor  20  may be completely processed in the first processor  10  and simply passes through the second processor  20 , or processed in the second processor  20  as a final displayable format. The second processor  20  may receive an inputted PC signal.  
         [0012]     When the display apparatus comprising two or more processors receives the OSD generating signal, each of the processors processing the video signal generates an OSD signal. As the OSD signals generated by each of the processors are different from each other, there is no uniformity therebetween. Also, resolution and brightness are changed by the processor&#39;s performance, thereby displaying the OSD in different qualities.  
         [0013]      FIG. 2  is a control block diagram of another conventional display apparatus to solve a problem of the OSD generation of the display apparatus in  FIG. 1 . As shown therein, a display apparatus comprises a first processor  10 , a second processor  20 , and an OSD processing chip  30 .  
         [0014]     The first processor  10  processes an externally inputted video signal, and outputs the processed video signal to the second processor  20 . The video signal may be inputted to the second processor  20  after being processed as a final predetermined format to be displayed, or may be inputted to the second processor  20  to be scaled.  
         [0015]     If a command to generate the OSD signal is received, the OSD processing chip  30  generates the OSD signal and outputs it to the second processor  20 .  
         [0016]     The second processor  20  mixes a PC signal inputted or the video signal outputted from the first processor  10  with the OSD signal generated from the OSD processing chip  30 .  
         [0017]     According to a control method which is set, the OSD signal generated and the video signal are mixed with each other by at least one processor. That is, the video signal and the PC signal may be mixed with the OSD signal in the processor processing each signal, or in another processor.  
         [0018]     The display apparatus illustrated in  FIG. 2  solved the problem of the display apparatus in  FIG. 1 . However, the display apparatus in  FIG. 2  additionally employs the OSD processing chip  30  instead of employing the OSD generator comprised in the processor, thereby generating extra expenses.  
       SUMMARY OF THE INVENTION  
       [0019]     Accordingly, it is an aspect of the present invention to provide a display apparatus, which generates a uniform OSD window and reduces costs.  
         [0020]     Additional aspects and/or advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the present invention.  
         [0021]     The foregoing and/or other aspects of the present invention are achieved by providing a display apparatus comprising a first processor outputting an OSD video signal or a processed first video signal comprising an OSD window; an OSD extractor extracting the OSD window from the OSD video signal; and a second processor mixing an externally inputted second video signal and the OSD window extracted from the OSD extractor, and outputting the mixed signal.  
         [0022]     According to an aspect of the present invention, the OSD extractor comprises a block determining position information on an area of an OSD window field from the OSD video signal outputted from the first processor, and a block extracting the OSD window from the OSD video signal by using the position information.  
         [0023]     The foregoing and/or other aspects of the present invention are also achieved by providing a method of controlling a display apparatus comprising receiving an OSD input signal; outputting an OSD video signal comprising an OSD window from a first processor; extracting the OSD window from the OSD video signal outputted from the first processor; and mixing an externally inputted second video signal and the OSD window extracted from an OSD extractor, and outputting the mixed signal.  
         [0024]     According to an aspect of the present invention, extracting the OSD window comprises determining position information on an area of the OSD window from the OSD video signal outputted from the first processor; and extracting the OSD window from the OSD video signal by using the position information. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0025]     The above and/or other aspects and advantages of the present invention will become apparent and more readily appreciated from the following description of exemplary embodiments, taken in conjunction with the accompanying drawings of which:  
         [0026]      FIG. 1  is a control block diagram of a conventional display apparatus;  
         [0027]      FIG. 2  is a control block diagram of another conventional display apparatus;  
         [0028]      FIG. 3  is a control block diagram of an exemplary embodiment of a display apparatus according to the present invention; and  
         [0029]      FIG. 4  is a control flow chart of the display apparatus according to an exemplary embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS  
       [0030]     Reference will now be made in detail to exemplary embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. The exemplary embodiments are described below in order to explain the present invention by referring to the figures.  
         [0031]     As shown in  FIG. 3 , a display apparatus according to an exemplary embodiment of the present invention comprises a first processor  40  and a second processor  60  to process video signals in different formats; and an OSD extractor  50 .  
         [0032]     The first processor  40  processes an externally inputted first video signal, and comprises an OSD generator  42 . The first processor  40  comprises blocks for processing the first video signal such as converting an externally inputted analog signal to a digital signal, decoding the first video signal in an encoded state, adjusting the processed first video signal into a predetermined resolution and color sensation, etc., and processing the inputted first video signal into a predetermined format to be displayed.  
         [0033]     When receiving an OSD input signal in order to generate an OSD signal while the first processor  40  processes the first video signal, the OSD generator  42  generates the OSD signal. The first processor  40  mixes the video signal processed by the first processor  40  with the OSD signal generated by the OSD generator  42 , and outputs the processed first video signal comprising the OSD window. The processed first video signal outputted from the first processor  40  simply passes through the second processor  60  to form an output to be displayed. A function of video signal scaling may be realized in either the first processor  40  or the second processor  60 , thus the first video signal may pass through the first processor  40  and scaling may be performed in the second processor  60 .  
         [0034]     The second processor  60  processes an externally inputted second video signal. As an exemplary embodiment of the present invention, the second video signal refers to a PC signal. The PC signal is different from the video signal received from a broadcasting station or generated from a video generating apparatus like a VTR in frequency band and resolution, thereby employing an extra processor for processing it.  
         [0035]     When receiving the OSD input signal while the second processor  60  processes the second video signal, the OSD generator  42  of the first processor  40  generates the OSD signal. At this time, the first processor  40  outputs an OSD video signal comprising the OSD signal, and the OSD video signal is inputted to the OSD extractor  50 .  
         [0036]     The OSD extractor  50  extracts an OSD window from the OSD video signal in one frame outputted from the first processor  40 . The OSD extractor  50  comprises blocks for determining position information on an area of the OSD window from the OSD video signal in one frame outputted from the first processor  40 , and for extracting the OSD window from the OSD video signal by using the position information. That is, after determining the position information on the OSD window area from the OSD video signal outputted from the first processor  40 , the OSD extractor  50  extracts the OSD window from the OSD video signal in one frame by using the position information. Then, the second processor  60  mixes the second video signal processed by the second processor  60  and the OSD window supplied from the OSD extractor  50 , and outputs the mixed signal.  
         [0037]     According to characteristics of the second video signal, the second processor  60  mixes the second video signal inputted and the OSD window either before or after processing the second video signal. For example, if the second video signal inputted is an analog signal, the second video signal goes through an A/D converting process before being mixed with the OSD position information as a digital signal. If the second video signal only requires a scaling to be displayed, the second video signal may be mixed with the OSD window extracted from the OSD extractor  50  to be processed into a predetermined format.  
         [0038]     The OSD extractor  50  does not comprise an extra process element or a chip, but comprises a part of the functions of the second processor  60 . As the processors are not provided with additional hardware for the OSD extractor  50 , a configuration thereof is different from employing a conventional OSD processing chip  30 .  
         [0039]     An exemplary embodiment of the present invention may receive a video signal having a different format from the first and second video signals, and comprise at least one processor processing such video signals. If the OSD window is required to be generated while the additional processor processes the video signal, it is possible to extract the OSD window generated from the first processor  40  to mix with the video signal inputted.  
         [0040]     Also, the display apparatus according to an exemplary embodiment of the present invention may comprise a controller (not shown) receiving the OSD input signal to make the first processor  40  output an OSD video signal comprising the OSD window, extracting the OSD window from the OSD video signal outputted from the OSD extractor  50 , and controlling to mix the second video signal and the OSD window in the second processor  60 .  
         [0041]      FIG. 4  is a control flow chart of the display apparatus according to an exemplary embodiment of the present invention.  
         [0042]     When receiving the OSD input signal at operation S 1 , the OSD generator  42  in the first processor  40  generates the OSD signal at operation S 2 . The OSD window according to the OSD signal generated by the OSD generator  42  is inputted to the second processor  60 . At operation S 3 , the OSD extractor  50  determines the position information on the OSD window area from the OSD video signal outputted from the first processor  40 , and extracts the OSD window from the position information at operation S 4 . At operation S 5 , the second processor  60  mixes the externally inputted second video signal and the OSD window extracted from the OSD extractor  50 , and outputs the mixed signal at operation S 6 .  
         [0043]     Although a few exemplary embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes may be made in these exemplary embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.