Display device and method of driving display device

A method of driving a display device including a display panel displaying an image, a controller receiving an image signal and generating a control signal, and a driver generating a driving signal in response to the control signal and providing the driving signal to the display panel, the method comprising:

• determining whether an external synchronization signal provided to the controller is in a normal state;
• generating the control signal based on a vertical synchronization signal and a horizontal synchronization signal generated based on a reference clock signal when it is determined that the external synchronization signal is in an abnormal state wherein the vertical synchronization signal includes information on a display section in which the image is displayed on the display panel and a blank section in which the image is not displayed on the display panel;
• generating a corrected synchronization signal by correcting the horizontal synchronization signal when the external synchronization signal is restored from the abnormal state to the normal state;
• determining whether the corrected synchronization signal is synchronized with the external synchronization signal;
• determining whether the vertical synchronization signal generated based on the reference clock signal is in the blank section;
• generating the control signal based on the corrected synchronization signal when the corrected synchronization signal is synchronized with the external synchronization signal and when the vertical synchronization signal is not in the blank section;
• and
• generating the control signal based on the external synchronization signal when the corrected synchronization signal is synchronized with the external synchronization signal and when the vertical synchronization signal is in the blank section.

An electronic device comprising:

• an electronic module including functional modules;
• a display panel displaying an image;
• a controller receiving an image signal and an external synchronization signal, determining whether the external synchronization signal is in a normal state, and generating a control signal;
• and
• a driver generating a driving signal in response to the control signal and providing the driving signal to the display panel,
• wherein the controller comprises:
• a synchronization signal generator generating a vertical synchronization signal and a horizontal synchronization signal based on a reference clock signal when it is determined that the external synchronization signal is in an abnormal state;
• a corrector correcting the horizontal synchronization signal to generate a corrected synchronization signal;
• a control signal generator generating the control signal;
• and
• a state determination circuit generating a state signal for controlling an operation of the control signal generator based on the vertical synchronization signal,
• wherein the vertical synchronization signal includes information on a display section in which the image is displayed on the display panel and a blank section in which the image is not displayed on the display panel,
• wherein the state determination circuit generates the state signal when the external synchronization signal is synchronized with the corrected synchronization signal and when the vertical synchronization signal is in the blank section, and
• wherein the control signal generator generates the control signal based on the horizontal synchronization signal when the external synchronization signal is in the abnormal state, generates the control signal based on the corrected synchronization signal when the external synchronization signal is synchronized with the corrected synchronization signal and when the control signal generator does not received the state signal from the state determination circuit, and generates the control signal based on the external synchronization signal when the external synchronization signal is synchronized with the corrected synchronization signal and when the control signal generator received the state signal from the state determination circuit.