Display apparatus for improving charging deviation

1 . A display apparatus, comprising:

a display panel; and

a source driver including a digital-to-analog converter configured to map image data to gamma voltages, obtained through voltage division between a high-level gamma voltage and a low-level gamma voltage, to generate a data voltage and output the data voltage to a data line of the display panel,

wherein a voltage difference between the high-level gamma voltage and the low-level gamma voltage is different at a first time and a second time in one frame.

2 . The display apparatus of claim 1 , wherein the source driver further comprises a gamma circuit configured to voltage-divide the voltage difference between the high-level gamma voltage and the low-level gamma voltage to generate the gamma voltages, based on a gray level of the image data.

3 . The display apparatus of claim 1 , wherein the display panel comprises:

a first pixel row including a plurality of first pixels; and

a second pixel row including a plurality of second pixels and disposed farther away from an output terminal of the source driver than the first pixel row, and

the voltage difference between the high-level gamma voltage and the low-level gamma voltage is greater in a second horizontal period, where the second pixel row is charged, than a first horizontal period where the first pixel row is charged.

4 . The display apparatus of claim 1 , wherein the data voltage output from the digital-to-analog converter, corresponding to the image data of the same gray level, increases over time in the one frame.

5 . The display apparatus of claim 1 , wherein, in the one frame, the high-level gamma voltage increases over time in the one frame, and the low-level gamma voltage decreases over time in the one frame.

6 . The display apparatus of claim 5 , wherein the source driver comprises:

a multi-feedback circuit configured to receive a reference feedback voltage at a reference position of the data line, receive first to n th feedback voltages at first to n th positions of the data line, and compare the reference feedback voltage with each of the first to n th feedback voltages to sequentially output first to n th deviation values;

a first calculation circuit configured to output first to n th high-level gamma voltage adjustment values and first to n th low-level gamma voltage adjustment values, based on the first to n th deviation values sequentially input thereto; and

a first auxiliary latch configured to store the first to n th high-level gamma voltage adjustment values and the first to n th low-level gamma voltage adjustment values, and then, supply the stored first to n th high-level gamma voltage adjustment values and first to n th low-level gamma voltage adjustment values to the digital-to-analog converter.

7 . The display apparatus of claim 6 , wherein the display panel comprises first to n th pixel rows,

the first to n th positions of the data line respectively correspond to the first to n th pixel rows of the display panel, and

the reference position of the data line is closer to an output terminal of the source driver than each of the first to n th positions of the data line.

8 . The display apparatus of claim 7 , wherein, during the one frame, a gamma voltage adjuster included in the digital-to-analog converter increases the high-level gamma voltage by one horizontal period unit, based on the first to n th high-level gamma voltage adjustment values, and decreases the low-level gamma voltage by one horizontal period unit, based on the first to n th low-level gamma voltage adjustment values.

9 . The display apparatus of claim 6 , wherein the source driver further comprises:

a comparator configured to compare a first latch storage value of image data, which is to be written in a first pixel row, with a second latch storage value of image data to be written in a second pixel row adjacent to the first pixel row to output a data deviation value by one horizontal period unit;

a second calculation circuit configured to multiply an intermediate compensation value based on the data deviation value by a predetermined position-based compensation gain to output a final compensation value; and

a second auxiliary latch configured to correct corresponding image data, based on the final compensation value, and then, supply the corrected image data to the digital-to-analog converter.

10 . The display apparatus of claim 9 , wherein the intermediate compensation value corresponding to the data deviation value is previously stored in a lookup table by gray level units.

11 . The display apparatus of claim 10 , wherein, in the intermediate compensation value, a center luminance of the display panel is a target value.