Method of driving display apparatus and plasma display apparatus

Abstract

The method of driving a display apparatus, in which the gradation scale is represented, by the subfield method, with less flicker even when driven at a frequency of 50 Hz has been disclosed. In this method, the two most weighted subfields (subfields of Bn brightness and Bn−1 brightness when it is assumed that the frame is composed of n subfields and the brightness of n subfields is Bi (i =1−n; B1≦B2 . . . Bn−1≦Bn)) are arranged at the interval of about half the length of the frame. Because of this, there exist two peaks of the light emission intensity in a frame, the interval being about half the length of the frame, and if the display apparatus is driven at a frequency of 50 Hz and the length of the frame is 20 ms, the variation period of the light emission intensity is 10 ms and the light emission intensity varies at 100 Hz, therefore, flicker is not detected.

1 . A method of driving a display apparatus in which a frame comprises n subfields, each subfield has at least an address period to select cells to be displayed and a light period to light the selected cells, the brightness of each subfield is determined by a number of lit pulses in said light period, a gradation scale is represented by combining the subfields to be lit among said plural subfields, and a length of a rest period, which is a period obtained by excluding the address period and the light period in each subfield, changes, 
 wherein a time interval between subfields of Bn brightness and Bn−1 brightness in the frame, when a brightness of said n subfields is assumed to be Bi (i =1−n; B1<B2 . . . Bn−1=Bn), is almost constant regardless of the length of said rest period.    
   
   
       2 . The method of driving a display apparatus as set forth in  claim 1 , wherein the time interval between subfields of Bn brightness and Bn=1 brightness is about half a length of said frame.  
   
   
       3 . The method of driving a display apparatus as set forth in  claim 1 , wherein start timings of the subfields of Bn brightness and Bn−1 brightness are respectively fixed in said frame.  
   
   
       4 . The method of driving a display apparatus as set forth in  claim 1 , wherein center positions of said light periods of the subfields of Bn brightness and Bn−1 brightness are respectively fixed in said frame.  
   
   
       5 . The method of driving a display apparatus as set forth in  claim 2 , wherein start timings of the subfields of Bn brightness and Bn−1 brightness are respectively fixed in said frame.  
   
   
       6 . The method of driving a display apparatus as set forth in  claim 2 , wherein center positions of said light periods of the subfields of Bn brightness and Bn−1 brightness are respectively fixed in same frame.  
   
   
       7 . The method of driving a display apparatus as set forth in  claim 1 , wherein said rest period is generated when a sum of lengths of said subfields becomes shorter than a period of said frame by decreasing a number of lit pulses in said frame.  
   
   
       8 . The method of driving a display apparatus as set forth in  claim 1 , wherein said frame is divided into a front frame and a rear frame whose periods have about equal lengths, wherein the subfield of Bn brightness is arranged at a start position of either of the front frame or the rear frame and the subfield Bn−1 brightness is arranged at a start position of the other of the front frame or the rear frame so that the time interval between subfields of Bn brightness and Bn−1 brightness is about half of a length of said frame.  
   
   
       9 . The method of driving a display apparatus as forth in  claim 7 , wherein said frame is divided into a front frame and rear frame whose periods have about equal lengths, wherein the subfield of Bn brightness is arranged at a start position of either of the front frame or the rear frame and the subfield of Bn−1 brightness is arranged at a start position of the other of the front frame or the rear frame so that the time interval between subfields of Bn brightness and Bn−1 brightness is about half of a length of said frame.  
   
   
       10 . The method of driving a display apparatus, as set forth in  claim 9 , wherein said rest period is divided and the divided rest periods are respectively arranged at rear positions of the front frame and the rear frame.