Optical device including optical modulation device, and driving method thereof

1. An optical device, comprising:

a display panel that displays an image;

a phase retardation plate disposed on the display panel that includes a quarter-wave plate; and

an optical modulation device that includes a first plate and second plate disposed to face each other, a liquid crystal layer disposed between the first plate and the second plate and that includes a plurality of liquid crystal molecules, and a plurality of unit areas,

wherein the first plate includes a plurality of lower electrodes that extend in a first direction and are arranged in a second direction that crosses the first direction, the second plate includes an upper electrode,

wherein light emitted from the display panel is received by the optical modulation device, and

when the display panel displays a first image during a first subframe, the optical modulation device applies a first driving signal to the plurality of lower electrodes and changes a circular polarization direction of light received from the phase retardation plate, and

when the display panel displays a second image during a second subframe following the first subframe, the optical modulation device applies a second driving signal different from the first driving signal to the plurality of lower electrodes and maintains the circular polarization direction of light received from the phase retardation plate.

2. The optical device of claim 1 , wherein

the display panel includes a polarizer that linearly polarizes light of an image.

3. The optical device of claim 1 , wherein the first plate includes a first aligner, the second plate includes a second aligner, and

an alignment direction of the first aligner and an alignment direction of the second aligner are substantially parallel to each other.

4. The optical device of claim 3 , wherein

the plurality of liquid crystal molecules tilt parallel to surfaces of the first plate and the second plate during the first subframe.

5. The optical device of claim 3 , wherein

long axes of the plurality of liquid crystal molecules are arranged in a direction parallel to the second direction.

6. The optical device of claim 3 , wherein

the plurality of liquid crystal molecules tilt perpendicular to the surfaces of the first plate and the second plate during the second subframe.

7. The optical device of claim 3 , wherein

the optical modulation device sequentially applies a first voltage to the lower electrodes included in the unit area along the second direction during the first subframe.

8. The optical device of claim 7 , wherein

time intervals of the first voltage respectively applied to the lower electrodes along the second direction during the first subframe are constant.

9. The optical device of claim 3 , wherein

the optical modulation device sequentially applies the first voltage to each of a plurality of groups of adjacent lower electrodes included in the unit area along the second direction.

10. The optical device of claim 9 , wherein

time intervals of the first voltage respectively applied to the groups along the second direction during the first subframe are constant.

11. The optical device of claim 3 , wherein

the optical modulation device simultaneously applies the first voltage to the plurality of lower electrodes during a first time interval of the first subframe, and the optical modulation device simultaneously applies a second voltage greater than the first voltage to the plurality of lower electrodes during a second time interval of the first subframe that follows the first time interval.

12. A method of driving an optical device that includes a display panel that emits light to displays an image, a phase retardation plate disposed on the display panel that includes a quarter-wave plate, and an optical modulation device that includes a first plate and a second plate disposed to face each other, and a liquid crystal layer disposed between the first plate and the second plate and that includes a plurality of liquid crystal molecules and receives light emitted from the display panel, the method comprising:

displaying, by the display panel, a first image during a first subframe;

applying, by the optical modulation device, a first driving signal to a plurality of lower electrodes included in the first plate during the first subframe, wherein the optical modulation device changes a circular polarization direction of light received from the phase retardation plate, wherein the plurality of liquid crystal molecules tilt parallel to surfaces of the first and second plates and long axes of the plurality of liquid crystal molecules arrange in a direction parallel to the second direction, wherein the lower electrodes extend in a first direction and are arranged in a second direction crossing the first direction;

displaying, by the display panel, a second image during a second subframe that follows the first subframe; and

applying, by the optical modulation device, a second driving signal different from the first driving signal to the plurality of lower electrodes during the second subframe, wherein the optical modulation device maintains the circular polarization direction of light received from the phase retardation plate, and wherein the plurality of liquid crystal molecules tilt perpendicular to the surfaces of the first and second plates.

13. The method of claim 12 , wherein

the first driving signal sequentially applies a first voltage to the lower electrodes included in a unit area of the optical modulation device along the second direction.

14. The method of claim 13 , wherein

time intervals of the first voltage sequentially applied to the lower electrodes along the second direction are constant.

15. The method of claim 12 , wherein

the first driving signal sequentially applies a first voltage to each of a plurality of groups of adjacent lower electrodes included in a unit area of the optical modulation device along the second direction.

16. The method of claim 15 , wherein

time intervals of the first voltage sequentially applied to the groups along the second direction during the first subframe are constant.

17. The method of claim 12 , wherein

the first driving signal simultaneously applies a first voltage to the plurality of lower electrodes during a first time interval of the first subframe, and simultaneously applies a second voltage greater than the first voltage to the plurality of lower electrodes during a second time interval of the first subframe that follows the first time interval.

18. The method of claim 12 , wherein the optical modulation device changes a circular polarization direction of light received from a phase retardation plate disposed on the display panel during the first subframe, and the optical modulation device maintains the circular polarization direction of light received from the phase retardation plate during the second subframe.