Patent ID: 7825919

Claim:
A circuit for generating a control signal for removal of an afterimage from an active matrix display device, the circuit comprising: a detector circuit which simultaneously determines if a first voltage from a first voltage source drops to a given voltage level and if a second voltage from a second voltage source drops to the given voltage level, and which outputs a detection signal when either one of the first and second voltages drops to the given voltage level; and an output circuit which receives the detection signal and outputs the control signal for removal of the afterimage from the active matrix display device, wherein the first voltage and the second voltage drop to the given voltage level at different lag times, wherein the detector circuit comprises a voltage level controller and a comparator circuit, wherein the voltage level controller comprises a first resistor and a first transistor connected in series between the first voltage source and a first node, a second transistor connected between a second node and a third node, and a second resistor connected between the first node and the second node, wherein the comparator circuit outputs the detection signal and comprises a comparator having a first input connected to the first node and a second input connected to the third node, and wherein gates of the first and second transistors are connected to the second voltage source.