Abstract:
A system for displaying image comprising an OLED panel. The OLED panel comprises a display area, a power line and a cathode line. The U-shaped power line is located on the first side, the second side and the third side of the OLED panel. The cathode line is located on the fourth side of the OLED panel.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The invention relates to an organic light emitting diode device. In particular, the invention relates to an active matrix organic light emitting diode. 
         [0003]    2. Description of the Related Art 
         [0004]      FIG. 1  shows a conventional AMOLED (Active Matrix Organic Light Emitting Diode) device  1 . AMOLED device  1  comprises panel  10  and Flexible printed circuit (FPC)  12 . Panel  10  comprises power line  14  and cathode line  15 . Power line  14  comprises four sections  14   a ,  14   b ,  14   c  and  14   d . FPC (flexible printed circuit)  12  has FPC power lines  13 - 1 ,  13 - 2 ,  13 - 3  and  13 - 4  and a FPC cathode line  19 . FPC power lines  13 - 1  and  13 - 2  are coupled to the power line  14   a , FPC power lines  13 - 3  and  13 - 4  are coupled to power lines  14   b  and  14   d  respectively and FPC cathode line  19  is coupled to cathode line  15 . Cathode line  15  is located on one side of the panel. Power line  14  surrounds panel  10  and supplies stable power. 
         [0005]    However, while power lines  14   d  and  14   a , cathode line  15  and FPC  12  are located at the top right corner of the panel  10  and only power lines  14   b  and  14 C are located at the bottom left corner of the panel  10 , the temperature at the top right corner of panel  10  is higher than that at the bottom left corner of panel  10  because there are more circuits at the top right corner of panel  10  than the bottom left corner of panel  10 . Thus, the panel can&#39;t emit light uniformly. In addition, because power lines  14   a ,  14   b ,  14   c  and  14   d  and cathode line  15  occupy a lot of panel area, the available emitting light area becomes less. 
       BRIEF SUMMARY OF THE INVENTION 
       [0006]    To solve the above-mentioned problem, the invention provides a system for displaying image, comprising an OLED panel. The OLED panel comprises a display area, four sides around the display area, a power line located on at least one side and a cathode line located on another side, wherein the power line and the cathode line located on different side. The power line can be U-shape, L-shape and strip shape. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]    The invention can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein: 
           [0008]      FIG. 1  shows a conventional AMOLED device. 
           [0009]      FIG. 2  shows an AMOLED device according to an embodiment of the invention. 
           [0010]      FIG. 3  shows an AMOLED device according to another embodiment of the invention. 
           [0011]      FIG. 4  shows an AMOLED device according to another embodiment of the invention. 
           [0012]      FIG. 5  shows an AMOLED device according to another embodiment of the invention. 
           [0013]      FIG. 6  schematically shows another embodiment of a system for displaying images. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0014]      FIG. 2  shows an AMOLED device  2  according to an embodiment of the invention. AMOLED device  2  comprises panel  20  and Flexible printed circuit  22 . Panel  20  comprises display area  16 , power line  24  and cathode line  25 . Power line  24  comprises three sections  24   a ,  24   b  and  24   c  to form a U-shape power line. Cathode line  25  is located on one side of panel  20 . U-shape power line  24  is located on the other three sides of panel  20 . Flexible printed circuit  22  has FPC power lines  23 - 1  and  23 - 2  and FPC cathode line  29 . FPC power line  23 - 1  is coupled to power line  24   a . FPC power line  23 - 2  is coupled to power line  24   c . FPC cathode line  29  is coupled to cathode line  25 . Current flows from FPC power lines  23 - 1  and  23 - 2  through power lines  24   a ,  24   c  and  24   b  to display area  16  and then from display area  16  through cathode line  25  to FPC cathode line  29 . Unlike the conventional panel  10 , panel  20  of the embodiment uses one less side of power line. Thus, panel  20  has a larger light emitting area. It also reduces circuits at the top right corner of the panel to lower temperature at the top right corner of the panel. The temperature at panel  20  is more uniform, so panel  20  emits light more uniformly. 
         [0015]      FIG. 3  shows an AMOLED device  3  according to another embodiment of the invention. AMOLED device  3  comprises panel  30  and Flexible printed circuit  32 . Panel  30  comprises display area  16 , power line  34  and cathode line  35 . Power line  34  comprises two sections  34   a  and  34   b  to form a L-shape power line. Cathode line  35  is located on one side of panel  30 . L-shape power line  34  is located on two adjacent sides of the panel. Flexible printed circuit  32  has FPC power line  33  and FPC cathode line  39 . FPC power line  33  is coupled to power line  34   a . FPC cathode line  39  is coupled to cathode line  35 . Current flows from FPC power line  33  serially through power line  34   a  and power line  34   b  to display area  16  and then from display area  16  serially through cathode line  35  to FPC cathode line  39 . Unlike panel  20  with three sides of power line, panel  30  uses one less side of power line, so panel  30  has a larger light emitting area. The number of circuits is also reduced at the top left corner of the panel to lower temperature at the top left corner of the panel. The temperature at panel  30  is more uniform, so panel  30  emits light more uniformly. 
         [0016]      FIG. 4  shows an AMOLED device  4  according to another embodiment of the invention. AMOLED device  4  comprises panel  40  and Flexible printed circuit  42 . Panel  40  comprises display area  16 , power line  44 , and cathode line  45 . Power line  44  is located on the opposite side of cathode line  45  of panel  40 . Power line  44  and cathode line  45  are symmetrically disposed on the panel  40 . Flexible printed circuit  42  has FPC power line  43  and FPC cathode line  49 . FPC power line  43  is coupled to power line  44 . FPC cathode line  49  is coupled to cathode line  45 . Current flows from FPC power line  43  serially through power line  44  to display area  16  and then from display area  16  serially through cathode line  45  to FPC cathode line  49 . 
         [0017]    Unlike panel  30  with two sides of power line, panel  40  uses one less side of power line. Thus, panel  40  has a larger light emitting area. It also reduces the number of circuits at the top left corner of the panel to lower temperature at the top left corner of the panel. 
         [0018]      FIG. 5  shows an AMOLED device  5  according to another embodiment of the invention. AMOLED device  5  comprises panel  50  and flexible printed circuits  52 - 1  and  52 - 2 . Panel  50  comprises display area  16 , power line  54 , and cathode line  55 . Cathode line  55  is located on one long side of panel  50 . Power line  54  is located on the opposite side of cathode line  55  of panel  50 . Power line  54  and cathode line  55  are symmetrically disposed on the panel  50 . Flexible printed circuit  52 - 1  has FPC cathode line  59 . Flexible printed circuit  52 - 2  has FPC power line  53 . FPC power line  53  is coupled to power line  54 . FPC cathode line  59  is coupled to cathode line  55 . Current flows from FPC power line  53  serially through power line  54  to display area  16  and then from display area  16  serially through cathode line  55  to FPC cathode line  59 . Unlike panel  30  with two sides of power line, panel  50  only has one power line, so panel  50  has a larger light emitting area. 
         [0019]    According to the embodiments of the invention of  FIG. 4  and  FIG. 5 , the power line and cathode line are symmetrically disposed on the panel. It avoids the conventional panel problem that relative circuits are too concentrated at the top right corner of the panel and the temperature at the top left corner of the panel is higher than the other place of the panel. Since the voltage and temperature of the panel are more uniform, the panel of the embodiments emits light more uniformly. The lifetime of the panel also increases. In addition, the power line and the cathode line are disposed on opposite side of the panel that simplifies circuit design. 
         [0020]      FIG. 6  schematically shows another embodiment of a system for displaying images, which, in this case, is implemented as display device  400  or electronic device  600 . The described active matrix organic electroluminescent device can be incorporated into a display device that can be an OLED device. As shown in  FIG. 6 , display device  400  comprises an active matrix organic electroluminescent device, such as the active matrix organic electroluminescent panel  20 ,  30 ,  40  and  50  shown in  FIG. 2 ,  FIG. 3 ,  FIG. 4  and  FIG. 5 . Display device  400  can form a portion of a variety of electronic devices (in this case, electronic device  600 ). Generally, electronic device  600  can comprise display device  400  and input unit  500 . Further, input unit  500  is operatively coupled to display device  400  and provides input signals (e.g., an image signal) to display device  400  to generate images. Electronic device  600  can be a mobile phone, digital camera, PDA (personal data assistant), notebook computer, desktop computer, television, car display, or portable DVD player, for example. 
         [0021]    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.