Abstract:
Driving circuits capable of outputting video data or OSD data selectively are used to serve as images on a display. The driving circuit which is integrated in a display panel comprises a selection unit that receives video data and on-screen-display (OSD) data and outputs the video data and the ODS data selectively according to a control signal, and a digital-to-analog conversion unit that converts the video data or the OSD data to an analog signal to drive a pixel array.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The invention relates to driving circuits, and in particular to a driving circuit integrated into a display panel capable of outputting video data or OSD data selectively to serve as images on a display.  
         [0003]     2. Description of the Related Art  
         [0004]     High definition, multicolor display, low power consumption, lower voltage requirements and light weight have made liquid crystal displays (LCDs) to be a leading display device technology. Further, On-Screen-Display (OSD) function is widely applied in display devices to adjust settings of the display devices. However, in display devices using digital interface, in order to implement OSD function, external printed circuits further require a switching IC to select video data or OSD data selectively to serve as images on a display, except for an OSD integrated circuit. This increases external printed circuit board and design complexity.  
       BRIEF SUMMARY OF THE INVENTION  
       [0005]     A detailed description is given in the following embodiments with reference to the accompanying drawings.  
         [0006]     Embodiments of driving circuits integrated in a display panel are provided, in which a selection unit receives video data and on-screen-display (OSD) data and outputs the video data and the ODS data selectively according to a control signal and a digital-to-analog conversion unit converts the video data or the OSD data to an analog signal to drive a pixel array.  
         [0007]     The invention also provides embodiments of a driving module, in which a printed circuit board comprises an on-screen-display (OSD) integrated circuit to generate OSD data and a control signal according to a horizontal synchronicity signal and a vertical synchronicity signal, and a driving circuit integrated into a display panel and coupled to a display array and the printed circuit board. The driving circuit comprises a selection unit receiving video data and the OSD data and outputting the video data and the ODS data selectively according to the control signal, and a digital-to-analog conversion unit converting the video data or the OSD data to an analog signal to drive the pixel array.  
         [0008]     The invention also provides embodiments of a display system, in which a printed circuit board comprises an on-screen-display (OSD) integrated circuit to generate OSD data and a control signal according to a horizontal synchronicity signal and a vertical synchronicity signal, and a display panel coupled to the printed circuit board and comprising a driving circuit and a display array. The driving circuit comprises a selection unit receiving video data and the OSD data and outputting the video data and the ODS data selectively according to the control signal, and a digital-to-analog conversion unit converting the video data or the OSD data to an analog signal to drive the pixel array.  
         [0009]     The invention also provides embodiments of electronic devices, in which the disclosed display system is provided and a power supply powers the display system to display images. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]     The invention can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein:  
         [0011]      FIG. 1A  shows an embodiment of a display system of the invention;  
         [0012]      FIG. 1B  shows another embodiment of a display system of the invention;  
         [0013]      FIG. 2  shows a relationship table related to external control signal and gray level multiplier; and  
         [0014]      FIG. 3  is a schematic view of an electronic device using display systems shown in  FIGS. 1A and 1B . 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0015]     The following description is of the best-contemplated mode of carrying out the invention. This description is made for the purpose of illustrating the general principles of the invention and should not be taken in a limiting sense. The scope of the invention is best determined by reference to the appended claims.  
         [0016]      FIG. 1A  shows an embodiment of a display system of the invention. As shown, the display system  100 A comprises a printed circuit board  10 A and a display panel  20 A.  
         [0017]     The printed circuit board  10 A comprises an on-screen-display (OSD) integrated circuit  12  generating OSD data OSDD and a control signal En 1  according to a horizontal synchronicity signal Hsync and a vertical synchronicity signal Vsync.  
         [0018]     The display panel  20 A is coupled to the printed circuit board  10 A and comprises a driving circuit  22  and a display array  24 . For example, the display panel  20 A can be a liquid crystal display panel, a plasma display panel or an organic light emitting display panel, but is not limited thereto. The driving circuit  22  comprises a selection unit  221 , a brightness contrast controller  222 , a gamma correction unit  223 , line inversion controller  224 , a digital-to-analog converter  225  and a Consultative Committee of International Radio (CCIR) decoder  226 . For example, the driving circuit  22  can be a data driver, wherein the pixel array  24  comprises a plurality of pixels (not shown) arranged in matrix and displays images according to analog signals from the digital-analog converter  225 .  
         [0019]     The CCIR decoder  226  decodes video data VD″, the horizontal synchronicity signal Hsync and the vertical synchronicity signal Vsync according to video input VD 1 , and outputs to the OSD integrated circuit  12  and the selection unit  221  respectively. For example, the video input VD 1  can meet with a CCIR656 format.  
         [0020]     The selection unit  221  receives the video data OSDD from the OSD integrated circuit  12  and the video data VD″ from the CCIR decoder  226 , and outputs them selectively according to the control signal En 1 . For example, the selection unit  221  can be a multiplexer or a switching unit, but is not limited thereto.  
         [0021]     The brightness contrast controller  222  controls brightness and contrast of the display panel  20 A, the gamma correction unit  223  adjusts non-linearity of the display panel  20 A, and the line inversion controller  224  controls line inversion of the display panel  20 A. The digital-to-analog converter  225  converts the video data VD″ or OSDD from the selection unit  221  to corresponding analog signals for driving display array  24 .  
         [0022]     Moreover, the OSD integrated circuit  12  further comprises a built-in storage unit (not shown) to store a relationship table (shown in  FIG. 2 ). The OSD integrated circuit  12  can adjust the corresponding gray levels in the OSD data OSDD according to the relationship table and an external control signal EC. For example, when receiving the OSDD data, the OSD integrated circuit  12  sets the gray level multiplier of 0.25 if the external control signal EC is 00. If the external control signal EC is 01, 10 and 11 respectively, the OSD integrated circuit  12  sets the gray level multiplier at 0.50, 0.75 and 1.00 respectively. When receiving no OSDD data, the OSD integrated circuit  12  sets the gray level multiplier to be zero, no matter what the external control signal EC is. Namely, gray levels in the OSD data OSDD can be adjusted according to the external control signal EC.  
         [0023]      FIG. 1B  shows another embodiment of a display system of the invention. As shown, the display system  100 B comprises a printed circuit board  10 B and a display panel  20 B.  
         [0024]     The printed circuit board  10 A comprises an on-screen-display (OSD) integrated circuit  12  and a digital processing unit  14 . The digital processing unit  14  generates video data VD 2 , a horizontal synchronicity signal Hsync and a vertical synchronicity signal Vsync, and the OSD integrated circuit  12  generates the OSD data OSDD and a control signal En 1  according to the horizontal synchronicity signal Hsync and the vertical synchronicity signal Vsync.  
         [0025]     The display panel  20 B is coupled to the printed circuit board  10 B and comprises a driving circuit  22  and a display array  24 . For example, the display panel  20 A can be a liquid crystal display panel, a plasma display panel or an organic light emitting display panel, but is not limited thereto. The driving circuit  22  comprises a selection unit  221 , a brightness contrast controller  222 , a gamma correction unit  223 , line inversion controller  224 , and a digital-to-analog converter  225 . For example, the driving circuit  22  can be a data driver, and the pixel array  24  comprises a plurality of pixels (not shown) arranged in matrix and display images according to analog signals from the digital-analog converter  225 .  
         [0026]     The selection unit  221  receives the video data OSDD from the OSD integrated circuit  12  and the video data VD 2  from the digital processing unit  14  and outputs them selectively according to the control signal En 1 . For example, the selection unit  221  can be a multiplexer or a switching unit, but is not limited thereto.  
         [0027]     The brightness contrast controller  222  controls brightness and contrast of the display panel  20 B, the gamma correction unit  223  adjusts non-linearity of the display panel  20 B, and the line inversion controller  224  controls line inversion of the display panel  20 B. The digital-to-analog converter  225  converts the video data VD 2  or OSDD from the selection unit  221  to corresponding analog signals to drive display array  24 .  
         [0028]     Similarly, the OSD integrated circuit  12  further comprises a built-in storage unit (not shown) to store a relationship table (shown in  FIG. 2 ). The OSD integrated circuit  12  can adjust the corresponding gray levels in the OSD data OSDD according to the relationship table and an external control signal EC. For example, when receiving the OSDD data, the OSD integrated circuit  12  sets the gray level multiplier of 0.25 if the external control signal EC is 00. If the external control signal EC is 01, 10 and 11, the OSD integrated circuit  12  sets the gray level multiplier at 0.50, 0.75 and 1.00 respectively. When receiving no OSDD data, the OSD integrated circuit  12  sets the gray level multiplier to be zero no matter what the external control signal EC is. Namely, gray levels in the OSD data OSDD can be adjusted according to the external control signal EC.  
         [0029]     Thus, the invention integrates the selection unit switching signals to the display panel, such that complication of the external printed circuit board is simplified and cost is reduced.  
         [0030]      FIG. 3  is a schematic view showing an electronic device using display systems shown in  FIGS. 1A and 1B . As shown, the electronic device  300  comprises a housing  310 , the display system  10 A or  100 B, and power supply  320 . The power supply  320  powers the display system  100 A or  100 B to display images. For example, the display system  100 A or  100 B can be a liquid crystal display panel, a plasma display panel or a organic light emitting display panel, and the electronic device  300  can be a PDA, a display monitor, a notebook computer, a table computer or a cellular phone.  
         [0031]     While the invention has been described by way of example and in terms of preferred embodiment, it is to be understood that the invention is not limited thereto. To the contrary, it is intended to cover various modifications and similar arrangements (as would be apparent to those skilled in the art). Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements.