Display driving device for reducing brightness deviation of display panel

A display driving device comprising:

• a sync signal generator configured to:
• receive a first vertical s vile signal having a first vertical period, and a first horizontal sync signal having a first horizontal period shorter than the first vertical period;
• and
• generate a second vertical sync signal having the first vertical period, and a second horizontal sync signal having a second horizontal period longer than the first horizontal period;
• a timing controller configured to receive image data to a display panel in response to the second horizontal sync signal during an active period of the first vertical period;
• and
• a buffer configured to store a portion of the image data that is not output to the display panel during the active period,
• wherein the sync signal generator counts the first vertical period by the first horizontal period to generate a first value, counts the first vertical period by a target value of the second horizontal period to generate a second value, counts the first horizontal period by a clock signal to generate a third valve, and determines the second horizontal period based on the first, second, and third values.

A display driving device comprising:

• a sync signal generator configured to:
• receive a first vertical sync signal having a first vertical period that includes a first vertical back porch period, a first vertical active period, and a first vertical front porch period;
• and
• generate a second vertical sync signal having a second vertical period that is the same with the first vertical period;
• and
• a timing controller configured to receive image data in response to a first horizontal sync signal having a first horizontal period, and to output to a display panel during the second vertical period in response to a second horizontal sync signal having a second horizontal period,
• wherein the sync signal generator generates the second vertical sync signal by delaying the first vertical sync signal by a predetermined delay time, and
• wherein the sync signal generator counts the first vertical period by the first horizontal period to generate a first value, counts the first vertical period by a target value of the second horizontal period to generate a second value, counts the first horizontal period by a clock signal to generate a third value, and determines the second horizontal period based on the first, second, and third values.