Source driver for display apparatus
The present invention relates to a source driver for a display apparatus, which is capable of removing delay of a DAC (Digital-Analog Converter) and in which a part of gamma lines for providing gamma voltages to the DAC is designed to have a large width and a small resistance value. Before driving a first gamma voltage to a level corresponding to display data, the DAC can select an adjacent gamma line having a small resistance value and drive a second gamma voltage, thereby removing a delay time.
1. A source driver for a display apparatus, comprising:
a first gamma line to which a first gamma voltage is applied;
a second gamma line which has a width wider than the first gamma line and to which a second gamma voltage is applied;
a decoder configured to receive the first gamma voltage and the second gamma voltage,
wherein the first gamma voltage corresponds to a target gray value based on input display data, the second gamma voltage corresponds to a gray value adjacent to, but different from, the target gray value;
outputting the first gamma voltage after outputting the second gamma voltage; and
a buffer configured to output a source voltage by using the first gamma voltage;
a transmission line configured to transmit the second gamma voltage and the first gamma voltage of the decoder to the buffer,
wherein a second delay time required for the second gamma voltage to be outputted from the decoder is shorter than a first delay time required for the first gamma voltage to be outputted from the decoder, due to a difference in width between the first gamma line and the second gamma line.
2. The source driver of claim 1 , wherein the decoder selects and drives outputs the second gamma voltage according to by coarse data contained in the display data, and then selects and drives outputs the first gamma voltage according to by fine data contained in the display data.
3. The source driver of claim 2 , wherein the decoder recognizes a part of bits contained in the display data as the coarse data, and recognizes the other bits as the fine data.
4. The source driver of claim 2 claim 3 , wherein the decoder recognizes low-order two bits of bits contained in the display data as the fine data, and recognizes the other bits as the coarse data.
5. The source driver of claim 1 , further comprising a plurality of gamma line groups, wherein each of the source driver comprises a plurality of gamma line lines which are divided into a plurality of groups comprises the second gamma line having a larger line width than the other gamma lines, wherein each group comprises the first gamma line and the second gamma line, and wherein the decoder outputs the second gamma voltage and the first gamma voltage by selecting a group corresponding to coarse data of the display data when the display data is inputted.