Display driver circuit and method for reducing influence of noise or dither

Abstract

The present invention provides a display driver circuit. A determination circuit is configured to select a first mode for encoding first image data based on a first set of conditions respectively corresponding to a first set of modes. An encoder is configured to encode the first image data in the first mode. The determination circuit is additionally configured to select a second mode for encoding second image data received (n−1)th after the first image data are received; and to select a third mode for encoding third image data received (n)th after the first image data are received, based on a second set of conditions respectively corresponding to the first set of modes. A second condition in the second set of the conditions corresponding to the second mode includes a wider range of values than a first condition in the first set of the conditions corresponding to the second mode.

What is claimed is: 
     
         1 . A display driver circuit comprising:
 an encoding mode determination circuit configured to select a first encoding mode for encoding first image data based on a first set of conditions respectively corresponding to a first set of encoding modes; and   an encoder configured to encode the first image data in the first encoding mode,   wherein the encoding mode determination circuit is further configured to:   select a second encoding mode for encoding second image data received (n−1)th after the first image data are received; and   select a third encoding mode for encoding third image data received (n)th after the first image data are received, based on a second set of conditions respectively corresponding to the first set of encoding modes,   wherein n is integer greater than one, and   wherein a second condition in the second set of the conditions corresponding to the second encoding includes wider range of values than a first condition in the first set of the conditions corresponding to the second encoding mode.   
     
     
         2 . The display driver circuit of  claim 1 , configured such that the first set of the conditions being used for selecting the first encoding mode are updated periodically or randomly. 
     
     
         3 . The display driver circuit of  claim 1 , wherein the first image data is image data first received after the display driver circuit is reset. 
     
     
         4 . The display driver circuit of  claim 1 , wherein the encoding mode determination circuit is further configured to:
 select the third encoding mode based on the first set of the conditions in a case where the third image data are first received after the display driver circuit is reset.   
     
     
         5 . The display driver circuit of  claim 1 , wherein the encoding mode determination circuit is further configured to:
 generate the conditions in the second set of the conditions based on the second encoding mode and the conditions in the first set of the conditions.   
     
     
         6 . The display driver circuit of  claim 1 , wherein the encoding mode determination circuit is further configured to:
 determine the third encoding mode as the same encoding mode as the second encoding mode in a case where a conversion value obtained from the third image data satisfies the second condition.   
     
     
         7 . The display driver circuit of  claim 6 , wherein the encoding mode determination circuit is further configured to:
 maintain the conditions in the second set of conditions and use those as a fourth set of conditions which is used for selecting a forth encoding mode for encoding forth image data received immediately following the third image data in a case where the conversion value satisfies the second condition.   
     
     
         8 . The display driver circuit of  claim 6 , wherein the encoding mode determination circuit is further configured to:
 generate the conversion value based on pixel values included in the third image data.   
     
     
         9 . The display driver circuit of  claim 1 , wherein the third image data are associated with an image to be displayed on a display panel, and
 wherein a color to be expressed in the image varies with the third encoding mode.   
     
     
         10 . The display driver circuit of  claim 9 , wherein, in a case where the third encoding mode is a first mode of the encoding modes, the color of the image is expressed in a combination of first colors corresponding to the first mode, and
 wherein, in a case where the third encoding mode is a second mode, which is different from the first mode, from among the encoding modes, the color of the image is expressed in a combination of second colors corresponding to the second mode.   
     
     
         11 . A display driver circuit comprising:
 an encoding mode determination circuit configured to   receive first image data, second image data, and third image data sequentially and successively,   select a first encoding mode for encoding the first image data among a plurality of encoding modes,   select a second encoding mode for encoding the second image data among the encoding modes based on a first set of conditions respectively corresponding to the encoding modes, the first set of conditions including a first condition corresponding to the second encoding mode, and   select a third encoding mode for encoding the third image data among the encoding modes based on a second set of conditions respectively corresponding to the encoding modes, the second set of conditions including a second condition corresponding to the third encoding mode; and   an encoder configured to encode the first image data in the first encoding mode that selected, and to encode the second image data in the second encoding mode that selected,   wherein, in a case where the second encoding mode is different from the first encoding mode, a second range corresponding to the second condition is wider range than a first range corresponding to the first condition.   
     
     
         12 . The display driver circuit of  claim 11 , wherein the second set of conditions are an adjusted set of conditions based on the first set of conditions. 
     
     
         13 . The display driver circuit of  claim 11 , wherein, in a case where the first encoding mode is identical to the second encoding mode, the first range is identical to the second range. 
     
     
         14 . The display driver circuit of  claim 11 , wherein the encoding mode determination circuit is further configured to:
 select the second encoding mode based on the conditions in the first set and a conversion value, the conversion value being obtained from the second image data.   
     
     
         15 . The display driver circuit of  claim 11 ,
 wherein a difference between the first range corresponding to the first condition and the second range corresponding to the second condition is associated with an error value corresponding to the first encoding mode.   
     
     
         16 . The display driver circuit of  claim 15 , wherein the error value is associated with noise occurring in the display driver circuit, or dither. 
     
     
         17 . The display driver circuit of  claim 11 ,
 wherein the encoding mode determination circuit is further configured to in a case where the third encoding mode is determined based on conditions of a predetermined reference set and a (n−1)th encoding mode for encoding (n−1)th received image data after the first image data is received is different from the third encoding mode, select a (n)th encoding mode for encoding (n)th received image data after the first image data are received based on a (n)th set of conditions, the predetermined reference set of conditions and the (n)th set of conditions including a (n−1)th condition and a (n)th condition corresponding to the (n−1)th encoding mode, respectively, and   wherein a (n)th range corresponding to the (n)th condition is wider range than a (n−1)th range corresponding to the (n−1)th condition.   
     
     
         18 . A display driver circuit comprising:
 an encoding mode determination circuit configured to   determine a first encoding mode for encoding first image data based on a first set of conditions corresponding to encoding modes, the first set of conditions including a first condition, and   determine a second encoding mode for encoding second image data received immediately following the first image data, based on a second set of conditions corresponding to the encoding modes, the second set of conditions including a second condition; and   an encoder configured to encode the first image data in the first encoding mode,   wherein the first condition in the first set of conditions includes a first range or set of criteria, and the second condition in the second set of conditions includes a second range or second set of criteria, wherein the second range is wider than and includes the first range, or the second set of criteria includes the first set of criteria.   
     
     
         19 . The display driver circuit of  claim 18 , further comprising:
 a memory configured to store the encoded first image data; and   a decoder configured to decode the stored first image data,   wherein the encoding mode determination circuit is further configured to:   identify the first encoding mode based on information included in a header of the stored first image data or the decoded first image data.   
     
     
         20 . The display driver circuit of  claim 18 , wherein the encoding mode determination circuit is further configured to:
 determine the second encoding mode as an encoding mode different from the first encoding mode in a case where a conversion value obtained from the second image data satisfies a third condition, which is different from the first condition and does not include the first range or set of criteria, from among the conditions in the second set of conditions.