Liquid crystal display and driving method thereof

A liquid crystal display device including a timing controller provided with a signal presence determiner for detecting an application of an input signal from an interface, wherein said signal presence determiner comprising:

• an oscillator for generating a reference clock having the same frequency as a horizontal synchronizing signal and a pre-synchronizing signal having the same frequency as a vertical synchronizing signal;
• a period detector for comparing a data enable signal from the exterior thereof with the reference clock to output a period of the input signal with the aid of a detection reference signal and the pre-synchronizing signal;
• a period comparator for comparing a period range between a desired maximum value and a desired minimum value of the input signal;
• and
• signal presence/absence comparing means for determining a presence/absence of the input signal in response to a pulse number of the input signal detected within a period range between the maximum value and the minimum value during an application interval of the detection reference signal.

A method of driving a liquid crystal display device including a timing controller provided with a signal presence determiner for detecting an application of an input signal from an interface, said method comprising the steps of:

• generating a reference clock having the same frequency as a horizontal synchronizing signal and a pre-synchronizing signal having the same frequency as a vertical synchronizing signal;
• comparing a data enable signal from the exterior with the reference clock to output a period of the input signal with the aid of at detection reference signal and the pre-synchronizing signal;
• comparing a period range between a desired maximum value and a desired minimum value of the input signal;
• and determining a presence/absence of the input signal in response to a pulse number of the input signal detected within a period range between the maximum value and the minimum value during an application interval of the detection reference signal.