DRIVING APPARATUS AND LIQUID CRYSTAL DISPLAY INCLUDING THE SAME

Abstract

A driving apparatus that can easily detect a failure occurring in a liquid crystal panel and a liquid crystal display comprising the driving apparatus for a display comprises a voltage generator generating first and second gate clock signals that are a combination of a gate-on signal and a gate-off signal, wherein the first and second gate clock signals control a turn-on/off condition of a gate line, and a signal comparator comparing the first gate clock signal and the second gate clock signal with each other and turning a timing controller for the display on or off according to a comparison result.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

Exemplary embodiments of the present invention will be understood in more detail from the following description taken in conjunction with the attached drawings in which

FIG. 1 is a block diagram of a liquid crystal display (LCD) according to an exemplary embodiment of the present invention;

FIG. 2 is an equivalent circuit diagram of a pixel in an LCD according to an exemplary embodiment of the present invention;

FIG. 3 is a block diagram of a gate driving circuit according to an exemplary embodiment of the present invention.

FIG. 4 is an equivalent circuit diagram of a shift register used in the circuit shown in FIG. 3;

FIG. 5 is an internal block diagram of a signal comparator according to an exemplary embodiment of the present invention; and

FIG. 6 is a flow chart showing an operation of the signal comparator according to an exemplary embodiment of the present invention.

Claims

1. A driving apparatus for a display comprising: a voltage generator generating first and second ate clock signals that are a combination of a gate-on signal and a gate-off signal, wherein the first and second gate clock signals control a turn-on/off condition of a gate line, anda signal comparator comparing the first gate clock signal and the second gate clock signal with each other and turning a timing controller for the display on or off according to a comparison result.

2. The driving apparatus for a display of claim 1, wherein the signal comparator determines whether a difference between the first gate clock signal and the second gate clock signal is in a range between a first reference voltage and a second reference voltage.

3. The driving apparatus for a display of claim 2, wherein the second reference voltage is a negative polarity voltage.

4. The driving apparatus for a display of claim 2, wherein the second reference voltage is a negative polarity voltage.

5. The driving apparatus for a display of claim 1, wherein the signal comparator includes: a subtractor comparing voltage levels of first gate clock signal and the second gate clock signal with each other and outputting a difference therebetween; anda signal detector receiving an output signal of the subtractor and, if the output signal is greater than the first reference voltage or smaller than the second reference voltage, outputting a high level signal to turn off the timing controller.

6. A driving apparatus for a display comprising: a voltage generator generating first and second gate clock signals that are a combination of a gate-on signal and a gate-off signal, wherein the first and second gate clock signals control a turn-on/off condition of a gate line; anda signal comparator including a first amplifier amplifying and outputting a difference between the first gate clock signal and the second gate clock signal, a second amplifier amplifying and outputting a difference between an output signal of the first amplifier and the gate-off signal, and a third amplifier amplifying and outputting a difference between an output signal of the first amplifier and a driving voltage.

7. The driving apparatus for a display of claim 6, wherein the first amplifier includes first and second voltage dividers dropping a voltage level of the first and second gate clock signals, respectively.

8. The driving apparatus for a display of claim 6, wherein the second amplifier includes a third voltage divider dropping a voltage level of the gate-off signal.

9. The driving apparatus for a display of claim 6, wherein the third amplifier includes a fourth voltage divider dropping the driving voltage.

10. The driving apparatus for a display of claim 7, wherein the first and second voltage dividers are resistor networks.

11. The driving apparatus for a display of claim 8, wherein the third voltage divider is a resistor network.

12. The driving apparatus for a display of claim 9, wherein the fourth voltage divider is a resistor network.

13. The driving apparatus for a display of claim 7, wherein one end of the first voltage divider is connected to an inverting input terminal of the second amplifier.

14. The driving apparatus for a display of claim 6, wherein the output terminal of the second amplifier is connected to an output terminal of the third amplifier.

15. A liquid crystal display comprising: a liquid crystal panel including a plurality of unit pixels having a respective plurality of switching devices arranged in a matrix, a plurality of gate lines and data lines connected to the plurality of switching devices and transmitting data and gate voltages, the gate lines extending to sides of the liquid crystal panel, and first and second gate drivers connected to the plurality of gate lines at both sides of the liquid crystal panel to which the plurality of gate lines extend;a timing controller receiving externally supplied image data and outputting data suitable for operating the liquid crystal panel and generating gate and data control signals for driving the first and second gate drivers and a data driver;a voltage generator generating first and second gate clock signals that are a combination of a gate-on signal and a gate-off signals, wherein the first and second gate clock signals control a turn-on/off condition of a gate line; anda signal comparator comparing the first gate clock signal and the second gate clock signal with each other, providing the first gate clock signal and the second gate clock to the first and second gate drivers, respectively, if the first gate clock signal and the second gate clock are the same, and turning off the timing controller if the first gate clock signal and the second gate clock signal are not the same; whereinthe data driver applies a data voltage to the plurality of data lines.

16. The liquid crystal display of claim 15, wherein the signal comparator determines whether a difference between the first gate clock signal and the second gate clock signal is in a range between a first reference voltage and a second reference voltage.

17. The liquid crystal display of claim 16, wherein the first reference voltage is a positive polarity voltage.

18. The liquid crystal display of claim 16, wherein the second reference voltage is a negative polarity voltage.

19. The liquid crystal display of claim 15, wherein the signal comparator comprises: a subtractor comparing voltage levels of the first gate clock signal and the second gate clock signal with each other, and outputting a difference therebetween; anda signal detector receiving an output signal of the subtractor and if the output signal is greater than the first reference voltage or smaller than the second reference voltage, outputting a high level signal to turn off the timing controller.

20. The liquid crystal display of claim 15, wherein the switching devices are made of amorphous silicon.

21. The liquid crystal display of claim 15, wherein the first and second gate drivers and the switching devices are formed on a same substrate.

22. The liquid crystal display of claim 15, wherein the first and second gate drivers are formed at the same time that the switching devices are formed.