Patent ID: 8009155

Claim:
An output buffer of a source driver applied in a display, wherein the output buffer comprises: an upper buffer used to output a positive polarity signal for driving a data line of the graphic display over an upper supply range which is from a first voltage (V 1 ) to a second voltage (V 2 ), the upper buffer comprising a first upper supply terminal and a first lower supply terminal, wherein the first voltage (V 1 ) is applied to the first upper supply terminal, and the second voltage (V 2 ) is applied to the first lower supply terminal; and a lower buffer used to output a negative polarity signal for driving another data line of the graphic displayer over a lower supply rang which is from a third voltage (V 3 ) to a fourth voltage (V 4 ), the lower buffer comprising an second upper supply terminal and a second lower supply terminal, wherein the third voltage (V 3 ) is applied to the second upper supply terminal, and the fourth voltage (V 4 ) is applied to the second lower supply terminal; wherein V 1 >V 2 , V 1 >V 4 , V 3 >V 2 , and V 3 >V 4 , and the second voltage is equal to a common voltage minus a predetermined differential voltage, and the third voltage is equal to the common voltage (Vcom) plus the predetermined differential voltage (ΔV).