Automatic reset circuit
A liquid crystal display (LCD) device includes a gate driver for supplying gate signals and a timing controller for generating a gate control signal to the gate driver. The LCD device further includes an automatic reset circuit which detects abnormal condition of the gate control signal and generates a reset signal.
1. A liquid crystal display (LCD) device, comprising:
a gate driver for supplying gate signals;
a timing controller for generating gate control signals including a gate start pulse to the gate driver;
a watchdog unit including a detecting unit and a control signal generating unit; and
a reset signal generating unit receiving a control signal from the control signal generating unit, generating a reset signal and providing it to the timing controller when the gate start pulse is not normally fed back,
wherein the detecting unit checks a feedback status of the gate start pulse during a several vertical synchronization periods to ensure the accuracy of determination prior to the output of a detection signal and transmits the detection signal to the control signal generating unit, and the control signal generating unit outputs a control signal upon receipt of the detection signal to the reset signal generating unit.
2. The LCD device of claim 1 , wherein the watchdog unit generates a detection signal upon receipt of a signal indicative of the feedback status of the gate start pulse.
3. The LCD device of claim 2 , further comprising:
a signal line to detect the feedback status of the gate start pulse.
4. The LCD device of claim 1 , wherein the reset signal is supplied to the timing controller and the timing controller generates a new start pulse.
5. The LCD device of claim 2 , wherein the signal indicative of the feedback status of the gate start pulse counts a number of signals that is fed back after the gate start pulse is sent to gate lines.
6. The LCD device of claim 3 , wherein the signal line generates the signal indicative of the feedback status of the gate start pulse.
7. A driving method of a liquid crystal display (LCD) device having a gate driver and a timing controller, comprising:
supplying a gate control signal including a gate start pulse to the gate driver from the timing controller;
checking and determining a feedback status of the gate start pulse by a detecting unit of a watchdog unit during a several vertical synchronization periods;
outputting a detection signal indicative of abnormal feedback status by the detecting unit of the watchdog unit to a control signal generating unit;
outputting a control signal upon receipt of the detection signal indicative of the abnormal feedback status to a reset signal generating unit by a control signal generating unit of the watchdog unit;
producing a reset signal by the reset signal generating unit in response to the control signal; and,
supplying the reset signal to the timing controller.
8. The method of claim 7 , wherein the determining the feedback status of the gate start pulse comprises counting a number of the gate control signal that is fed back after the gate start pulse is sent to gate lines.
9. The method of claim 8 , wherein the counting the number of the gate start pulse is repeated during multiple vertical synchronization periods.
10. The method of claim 7 , further comprising:
transferring the determined feedback status of the gate start pulse via a signal line from the gate driver.
11. The method of claim 7 , further comprising:
at the timing controller, generating a new gate start pulse upon receipt of the reset signal and supplying the new gate start pulse to the gate driver.