Display device having reduced flicker

Abstract

A driving apparatus for a display device and display device having the driving apparatus. The display device has a plurality of pixels each having a switching element. The driving apparatus includes a gate line connected to the switching element, a gate driver to apply a gate signal having first to third voltages to the gate line, a first voltage generator to generate the first and third voltages, and a second voltage generator to generate the second voltage. The first and second voltages turn on the switching element, and the third voltage turns off the switching element. The second voltage is less than the first voltage. Thus, since the gate driver includes the second voltage generator to generate the second voltage and a plurality of transistors, and generates a gate output having a step shape, a kickback voltage is reduced and flicker is prevented.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other features of the present invention may become more apparent from the ensuing description when read together with the accompanying drawing, in which:

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

FIG. 2 is an equivalent circuit diagram of a pixel of a liquid crystal display of the present invention;

FIG. 3 is a circuit diagram of the voltage generator illustrated in FIG. 1;

FIG. 4 is a circuit diagram of the gate driver illustrated in FIG. 1; and

FIG. 5 is a signal waveform diagram of the gate driver of FIG. 4.

Claims

1. A driving apparatus for a display device having a plurality of pixels each having a switching element, comprising: a gate line connected to the switching element;a gate driver to apply a gate signal having first to third voltages to the gate line;a first voltage generator to generate the first and third voltages; anda second voltage generator to generate the second voltage, wherein the first and second voltages turn on the switching element, and the third voltage turns off the switching element, and the second voltage is less than the first voltage.

2. The apparatus of claim 1, further comprising a signal controller to generate first and second control signals and to control the gate driver.

3. The apparatus of claim 2, wherein the gate driver includes: first and second transistors to output the first and second voltages in response to the first control signal, respectively; andthird and fourth transistors to output the second and third voltages in response to the second control signal, respectively.

4. The apparatus of claim 3, wherein the first and fourth transistors are N-type transistors, and the second and third transistors are P-type transistors.

5. The apparatus of claim 4, wherein the gate driver further includes an output end connected to output terminals of the first, third, and fourth transistors.

6. The apparatus of claim 5, wherein a time for applying the first voltage and a time for applying the second voltage are the same.

7. The apparatus of claim 5, wherein a time for applying the first voltage and a time for applying the second voltage are different.

8. The apparatus of claim 1, wherein the second voltage generator includes an operational amplifier having a non-inversion terminal connected to a predetermined reference voltage, and an inversion terminal connected to an output end and a ground voltage through first and second resistors, respectively.

9. The apparatus of claim 8, wherein the operational amplifier has a bias voltage as the first voltage.

10. The apparatus of claim 9, wherein the first resistor is a variable resistor.

11. The apparatus of claim 10, wherein the variable resistor is a digital variable resistor.

12. A display device comprising: a plurality of pixels, each having a switching element;a gate line connected to the switching element,a gate driver to transfer a gate signal having first to third voltages to the gate line;a first voltage generator to generate the first and third voltages;a second voltage generator to generate the second voltage; anda signal controller to generate a plurality of control signals and to control the gate driver,wherein the first and second voltages turn on the switching element, and thethird voltage turns off the switching element, andthe second voltage is less than the first voltage.

13. The device of claim 12, wherein the gate driver includes: first and second transistors to output the first and second voltages in response to a first control signal among the control signals, respectively; andthird and fourth transistors to output the second and third voltages in response to a second control signal among the control signals, respectively.

14. The device of claim 13, wherein the first and fourth transistors are N-type transistors, and the second and third transistors are P-type transistors.

15. The device of claim 14, wherein the gate driver further includes an output end connected to output terminals of the first, third, and fourth transistors.

16. The device of claim 15, wherein a time for applying the first voltage and a time for applying the second voltage are the same.

17. The device of claim 15, wherein a time for applying the first voltage and a time for applying the second voltage are different.

18. The device of claim 12, wherein the second voltage generator includes an operational amplifier having a non-inversion terminal connected to a predetermined reference voltage, and an inversion terminal connected to an output end and a ground voltage through first and second resistors, respectively.

19. The device of claim 18, wherein the operational amplifier has a bias voltage as the first voltage.

20. The device of claim 19, wherein the first resistor is a variable resistor.

21. The device of claim 20, wherein the variable resistor is a digital variable resistor.