Method for driving display device to hide transient behavior

Abstract

The major characteristics of the present invention lies in that, on one hand, conventional driving or overdriving techniques that do not add significant cost to the display device are used for scanning while, on the other hand, the direct-lit, LED-based backlight is turned off during the pixels' transient period where their grey levels gradually approach or overshoot above the target grey levels so that the residuals of the dynamic images during the transient period are not manifested.

1 . A method for driving a display device having a direct-lit backlight module having a plurality of LEDs as light source arranged in a plurality of horizontal rows where said display has a panel positioned in front of said backlight module, said panel has a plurality of horizontal scan lines and a plurality of vertical data lines, the intersection of a said scan line and a said data line defines a pixel of said panel, said pixel is turned by enabling said scan line, supplying a driving voltage on said data line, and turning on a row of said LEDs behind said pixel, said pixel has a retardation property with which the grey level of said pixel gradually approaches the grey level corresponding to said driving voltage, said method comprising the steps of:
 within the period of a frame, applying an overdriving voltage to said pixel that is larger than the voltage corresponding to a target grey level of said pixel within said period; and   within said period, applying a control signal whose frequency is at least equal to the frame rate of said display device so that, during at least a portion of the process where the grey level of said pixel is approaching said target grey level, said row of said LED is turned off.   
   
   
       2 . The method according to  claim 1 , wherein said display device is one of a LCD device, a plasma display device, and an OLED device. 
   
   
       3 . The method according to  claim 1 , wherein the frequency of said control signal is twice of the frame rate of said display device. 
   
   
       4 . A method for driving a display device having a direct-lit backlight module having a plurality of LEDs as light source arranged in a plurality of horizontal rows where said display has a panel positioned in front of said backlight module, said panel has a plurality of horizontal scan lines and a plurality of vertical data lines, the intersection of a said scan line and a said data line defines a pixel of said panel, said pixel is turned by enabling said scan line, supplying a driving voltage on said data line, and turning on a row of said LEDs behind said pixel, said pixel has a retardation property with which the grey level of said pixel gradually approaches the grey level corresponding to said driving voltage, said method comprising the steps of:
 within the period of a frame, applying an overdriving voltage to said pixel that is larger than the voltage corresponding to a target grey level of said pixel within said period; and   within said period, applying a control signal whose frequency is at least equal to the frame rate of said display device so that, during when said row of said LED is turned on, the integration of said pixel's grey level over time is substantially zero.   
   
   
       5 . The method according to  claim 4 , wherein said display device is one of a LCD device, a plasma display device, and an OLED device. 
   
   
       6 . The method according to  claim 4 , wherein the frequency of said control signal is twice of the frame rate of said display device. 
   
   
       7 . The method according to  claim 4 , wherein, with said period, said overdriving voltage is reduced to an appropriate lower level when the grey level of said pixel overshoots above said target grey level and said row of said LEDs is turned off. 
   
   
       8 . The method according to  claim 7 , wherein said appropriate lower level is equal to the driving voltage corresponding to said target grey level of said pixel within said period. 
   
   
       9 . A method for driving a display device having a direct-lit backlight module having a plurality of LEDs as light source arranged in a plurality of horizontal rows where said display has a panel positioned in front of said backlight module, said panel has a plurality of horizontal scan lines and a plurality of vertical data lines, the intersection of a said scan line and a said data line defines a pixel of said panel, said pixel is turned by enabling said scan line, supplying a driving voltage on said data line, and turning on a row of said LEDs behind said pixel, said pixel has a retardation property with which the grey level of said pixel gradually approaches the grey level corresponding to said driving voltage, said method comprising the steps of:
 within an initial portion of the period of a frame, applying an overdriving voltage to said pixel that is larger than the voltage corresponding to a target grey level of said pixel within said period and then, with the remaining portion of said period, applying a driving voltage to said pixel that is equal to the voltage corresponding to said target grey level of said pixel; and   within said period, applying a control signal whose frequency is at least equal to the frame rate of said display device so that, during at least a portion of the process where the grey level of said pixel is approaching said target grey level, said row of said LED is turned off.   
   
   
       10 . The method according to  claim 9 , wherein said display device is one of a LCD device, a plasma display device, and an OLED device. 
   
   
       11 . The method according to  claim 9 , wherein the frequency of said control signal is twice of the frame rate of said display device.