Four color liquid crystal display and driving device and method thereof

Abstract

A four color liquid crystal display (LCD) including red, green, blue, and white pixels is provided. The LCD also includes a plurality of gate lines for transmitting gate signals to the pixels and a plurality of data lines for transmitting data signals to the pixels. The LCD further includes a gate driver supplying the gate signals to the gate lines, a data driver supplying the data voltages to the data lines, and an image signal modifier. The image signal modifier includes a data converter converting three-color image signals into four-color image signals, a data optimizer optimizing the four-color image signals from the data converter, a data output unit supplying the optimized image signals to the data driver in synchronization with a clock, and a clock generator generating the clock. The data driver operates in synchronization with the clock.

1 - 18 . (canceled) 
   
   
       19 . A device of driving a four color liquid crystal display including a plurality of red, green, blue, and white pixels arranged in a matrix, the device comprising:
 a gray voltage generator generating a plurality of gray voltages;   an image signal modifier for converting three-color image signals into four-color image signals and selecting one of the three-color image signals and the four-color image signals; and   a data driver converting the selected image signals into data voltages selected from the gray voltages and applying the data voltage to the pixels.   
   
   
       20 . The device of  claim 19 , wherein the image signal modifier comprises:
 a data converter converting the three-color image signals into the four-color image signals; and   a data selector for selecting one of the three-color image signals and the four-color image signals based on a predetermined condition.   
   
   
       21 . The device of  claim 20 , wherein the selection of the data selector is based on difference between current image signals and previous image signals. 
   
   
       22 . The device of  claim 21 , wherein the four-color image signals are selected when the difference between the current image signals and the previous image signals is larger than a predetermined value and the three-color image signals are selected when the difference between the current image signals and the previous image signals is equal to or smaller than the predetermined value. 
   
   
       23 . The device of  claim 20 , wherein the selection of the data selector is based on a selection signal from an external device. 
   
   
       24 . The device of  claim 23 , wherein a state of the selection signal is determined by a user. 
   
   
       25 . The device of  claim 24 , wherein the state of the selection signal is determined by operation modes of the liquid crystal display and the operation modes include a normal mode and a TV mode. 
   
   
       26 . The device of  claim 20 , wherein the data selector selects both a group of the three-color image signals and a group of the four-color image signals. 
   
   
       27 . The device of  claim 26 , wherein the liquid crystal display has a PIP (picture-in-picture) function and the selected part of the four-color images signals corresponds to the pixels displaying the PIP. 
   
   
       28 . The device of  claim 20 , wherein the four-color image signals are selected when a supply voltage provided for the liquid crystal display is a DC voltage and the three-color image signals are selected when the supply voltage provided for the liquid crystal display is an AC voltage. 
   
   
       29 . The device of  claim 20 , wherein the image signal modifier further comprises a data optimizer optimizing the four-color image signals from the data converter based on a characteristic of the liquid crystal display and provides the optimized four-color image signals for the data selector. 
   
   
       30 . The device of  claim 29 , wherein the data selector comprises a multiplexer selecting one of the three -color image signals and the four-color image signals based on a selection signal. 
   
   
       31 . The device of  claim 30 , wherein the image signal modifier further comprises a delay unit delaying the three-color image signals for a predetermined time and supplying the delayed three-color image signals to the multiplexer. 
   
   
       32 . The device of  claim 31 , wherein the predetermined time is substantially equal to a time for the three-color image signals to reach the multiplexer through the data converter and the data optimizer. 
   
   
       33 . (canceled) 
   
   
       34 . A method of driving a four color liquid crystal display including a plurality of gate lines, a plurality of data lines, and a plurality of red, green, blue, and white pixels arranged in a matrix, the method comprising:
 converting three-color image signals into four-color image signals;   selecting one of the three-color image signals and the four-color image signals;   converting the selected image signals into data voltages;   applying a gate voltage to the gate lines; and   applying the data voltages into the data lines.   
   
   
       35 . The method of  claim 34 , further comprising:
 optimizing the four-color image signals before the signal selection; and   delaying the three-color image signals for a predetermined time before the signal selection.   
   
   
       36 . A display device comprising:
 a plurality of pixels having color pixels and a white pixel, each pixel including a pixel electrode and a switching element; and   a black matrix enclosing the color pixels and the white pixels,   wherein at least one portion of the black matrix enclosing the white pixel is wider than other portions of the black matrix enclosing the color pixels.   
   
   
       37 . The display device of  claim 36 , wherein the color pixels include red, green, and blue pixels.