Patent ID: 8581817

Claim:
A liquid crystal display (LCD) comprising: an onscreen display (OSD) system comprising an input system for setting a gamma value of the LCD; and a gamma correction circuit comprising a look-up table, the look-up table comprising a plurality of sub-look-up tables each corresponding to a gamma value and having a plurality of original gray level values and a plurality of corrected gray level values corresponding to the plurality of original gray level values; wherein the gamma correction circuit is configured for receiving an original gray level value of a video signal, and determining a corresponding corrected gray level value according to a gamma value set through the input system and a sub-look-up table corresponding to the gamma value set through the input system; wherein the look-up table further includes a common look-up table corresponding to all available gamma values of the LCD, the common look-up table having a plurality of original gray level values and a plurality of corrected gray level values corresponding to the plurality of original gray level values, gray levels of the plurality of original gray level values of the common look-up table not exceeding a predetermined value, gray levels of a plurality of original gray level values of the sub-look-up table corresponding to the gamma value set through the input system exceed the predetermined value, and the gamma correction circuit sets the sub-look-up table corresponding to the gamma value set through the input system and the common look-up table as active look-up tables; wherein the combination of the sub-look-up table and the common look-up table stores complete original gray level values and a plurality of corrected gray level values corresponding to the complete original gray level values for a gamma value corresponding to the sub-look-up table.