TFT-LCD capable of repairing discontinuous lines

A TFT-LCD (Thin Film Transistor Liquid Crystal Display) capable of repairing discontinuous lines, the LCD having at least one scan line driving unit for driving a plurality of scan lines, at least one data line driving unit for driving a plurality of data lines, and a plurality of repairing circuits for repairing discontinuous scan lines among the scan lines, each of the repairing circuits comprising:

• at least one input terminal repairing trace, wherein when there is at least a discontinuous scan line needed to be repaired, one of the input terminal repairing traces is connected to one of the discontinuous scan lines;
• a plurality of repairing OP amplifiers each having an input terminal, an output terminal and a control terminal, the input terminal of one of the repairing OP amplifiers is connected to the input terminal repairing trace connected to one of the discontinuous scan lines;
• a high-impedance detecting module for detecting a voltage at the input terminal of each of the repairing OP amplifiers and generating an OP control signal for each of the repairing OP amplifiers, the OP control signal being disabled when the input terminal of the corresponding repairing OP amplifier is floating, otherwise the OP control signal being enabled;
• and
• at least one output terminal repairing trace connected to the output terminal of each of the repairing OP amplifiers,
• wherein each of the repairing OP amplifiers further receives the corresponding OP control signal of the high-impedance detecting module and sets its output terminal to a high-impedance state when the corresponding OP control signal is disabled, and the OP amplifier outputs a signal according to the voltage at the input terminal when the OP control signal is enabled.

A high-impedance detecting unit for detecting whether a connection point has a high-impedance, the high-impedance detecting unit comprising:

• a first switch being controlled by a first switch control signal and having a first terminal and a second terminal, the first terminal being coupled to the connection point;
• a resistor having a first terminal and a second terminal, the first terminal being grounded;
• a second switch being controlled by a second switch control signal and having a first terminal and a second terminal, the first terminal of the second switch being coupled to the second terminal of the resistor, the second terminal of the second switch being coupled to the second terminal of the first switch;
• a capacitor having a first terminal, which is grounded, and a second terminal, which is coupled to the second terminal of the first switch;
• a comparator for comparing a voltage at the second terminal of the first switch with a reference voltage, and outputting a comparison signal;
• and
• a logic processing unit for receiving the comparison signal, and enabling or disabling a control signal according to a voltage of the comparison signal;
• wherein the first switch is first turned on for a period of time and then turned off and then the second switch is turned on for a period of time in a repeated manner.