Patent ID: 7791599

Claim:
A method of driving a display comprising: receiving an input signal having a first period corresponding to a number of lines in the display; generating a detection reference signal to compare periods of the input signal and a pre-synchronizing signal; determining whether the first period is less than a first reference period; outputting a signal of a first state to a signal presence comparator only if the first period is less than the first reference period; outputting the signal of the first state to a signal absence comparator only if the first period is beyond a range of the first reference period; determining the presence of the input signal if the number of pulses of the signal of the first state outputted to the signal presence comparator is larger than a predetermined plural number during an input interval of the detection reference signal, being different from the signal of the first state, wherein each of the pulses is to be of the first state and continuously has same values; and determining the absence of the input signal if the number of pulses of the signal of the first state outputted to the signal absence comparator is smaller than a predetermined plural number during an input interval of the detection reference signal, being different from the signal of the first state, wherein each of the pulses is to be of the first state and continuously has same values.