DISPLAY DEVICE AND A DRIVING METHOD FOR THE DISPLAY DEVICE

• US 20160216540A1
• Filed: 09/08/2015
• Published: 07/28/2016
• Est. Priority Date: 01/26/2015
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Inventors: CHO, JUNG-HYUN, Jeong, Seung Jun
• Granted Patent: US 9,977,251 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G02B 3/14 of variable focal length
• CPC Class Codes: G02B 30/27 involving lenticular arrays
• CPC Class Codes: G02B 30/28 involving active lenticular arrays
• CPC Class Codes: G02F 1/133526 Lenses, e.g. microlenses or Fresnel lenses
• CPC Class Codes: G02F 1/133536 Reflective polarizers G02F1/13362 takes precedence
• CPC Class Codes: G02F 1/133562 on the viewer side
• CPC Class Codes: G02F 1/133638 Waveplates, i.e. plates with a retardation value of lambda/n
• CPC Class Codes: G02F 1/134309 characterised by their geometrical arrangement
• CPC Class Codes: G02F 1/134381 Hybrid switching mode, i.e. for applying an electric field with components parallel and orthogonal to the substrates
• CPC Class Codes: G02F 1/13471 in which all the liquid crystal cells or layers remain transparent, e.g. FLC, ECB, DAP, HAN, TN, STN, SBE-LC cells G02F1/13475 takes precedence
• CPC Class Codes: G02F 2203/62 Switchable arrangements whereby the element being usually not switchable

Abstract

A display device includes a display panel, a first polarizer, a liquid crystal lens, a first quarter-wave plate, and a second quarter-wave plate. The display panel displays an image. The first polarizer disposed on the display panel reflects a first light having a polarization direction parallel to a reflection axis of the first polarizer. The liquid crystal lens includes liquid crystal molecules and changes a phase of the first light or a second light according to a driving signal applied to the liquid crystal lens. The second and first lights travel in opposite directions with respect to each other. The first quarter-wave plate is disposed between the first polarizer and the liquid crystal lens. The second quarter-wave plate is disposed between the liquid crystal lens and a second polarizer. The display device operates in a mirror mode, a three-dimensional mode, and a two-dimensional mode according to the driving signal.

Claims

1. A display device comprising:

a display panel displaying an image;

a first polarizer disposed on the display panel, the first polarizer having a reflection axis and reflecting a first light having a polarization direction parallel to the reflection axis;

a liquid crystal lens including liquid crystal molecules and changing a phase of the first light or a second light according to a driving signal applied to the liquid crystal lens, wherein the second light and the first light travel in opposite directions with respect to each other;

a first quarter-wave plate disposed between the first polarizer and the liquid crystal lens, the first quarter-wave plate including a first alignment axis and performing conversion between a first circularly polarized light and a first linearly polarized light; and

a second quarter-wave plate disposed between the liquid crystal lens and a second polarizer, the second quarter-wave plate including a second alignment axis and performing conversion between a second circularly polarized light and a second linearly polarized light,

wherein the display device operates in a mirror mode, a three-dimensional (3D) mode, and a two-dimensional (2D) mode according to the driving signal.

2. The display device of claim 1, wherein:

the first alignment axis and the second alignment axis are substantially parallel to each other.

3. The display device of claim 2, wherein:

the liquid crystal lens includes a plurality of lower electrodes forming an electric field in the liquid crystal molecules according to the driving signal, and

arrangement directions of the liquid crystal molecules are determined by the electric field.

4. The display device of claim 3, wherein:

in the mirror mode,

the liquid crystal molecules are arranged to be substantially vertical with respect to a plane on which the plurality of lower electrodes is arranged.

5. The display device of claim 3, wherein:

in the 3D mode,

the driving signal is applied so that the liquid crystal molecules are arranged to generate a binocular disparity for the image by changing the phase of the second light pertaining to the image through the arranged liquid crystal molecules.

6. The display device of claim 3, wherein:

in the 2D mode,

the driving signal is applied so that the liquid crystal molecules are arranged in substantially the same direction on a plane on which the plurality of lower electrodes is arranged.

7. The display device of claim 6, wherein:

the driving signal is a first threshold voltage driving signal sequentially applied to the plurality of lower electrodes.

8. The display device of claim 6, wherein:

the driving signal is second voltage driving signals increasing in a step-wise manner, and the second voltage driving signals are sequentially applied to the plurality of lower electrodes, respectively.

9. The display device of claim 6, wherein:

the driving signal is a third voltage driving signal simultaneously applied to the plurality of lower electrodes.

10. The display device of claim 1, wherein:

the first alignment axis and the second alignment axis are substantially vertical with respect to each other.

11. A driving method for a display device

the method comprising:

operating the display device in a mirror mode in which a first polarizer of the display device reflects first light having a polarization direction parallel to a reflection axis of the first polarizer;

operating the display device in a three-dimensional (3D) mode in which a 3D image is displayed by generating a binocular disparity for an image in a liquid crystal lens; and

operating the display device in a two-dimensional (2D) mode in which the image passes through the liquid crystal lens without being refracted.

12. The method of claim 11, wherein the display device includes:

the display panel displaying the image;

the first polarizer disposed on the display panel;

a first quarter-wave plate disposed on the first polarizer, the first quarter-wave plate including a first alignment axis and performing conversion between a first circularly polarized light and a first linearly polarized light,

a liquid crystal lens disposed on the first quarter-wave plate, the liquid crystal lens including liquid crystal molecules; and

a second quarter-wave plate disposed on the liquid crystal lens, the second quarter-wave plate including a second alignment axis and performing conversion between a second circularly polarized light and a second linearly polarized light.

13. The method of claim 12, wherein:

the first alignment axis and the second alignment axis are substantially parallel to each other.

14. The method of claim 11, wherein:

the liquid crystal lens includes a plurality of lower electrodes forming an electric field generated in the liquid crystal lens according to a driving signal applied to the plurality of lower electrodes

liquid crystal molecules of the liquid crystal lens are arranged by the electric field, and

wherein a driving signal applied to the plurality of lower electrodes is 0 volt.

15. The method of claim 14, wherein:

in the mirror mode, the liquid crystal molecules are arranged to be substantially vertical with respect to a plane on which the plurality of lower electrodes is arranged.

16. The method of claim 14, wherein:

in the 3D mode, when a second driving signal is applied to the liquid crystal lens as the driving signal, the liquid crystal molecules are arranged on a plane on which the plurality of the lower electrodes is arranged.

17. The method of claim 14, wherein:

in the 2D mode, when a third driving signal is applied to the liquid crystal lens as the driving signal, and

the liquid crystal molecules are arranged in substantially the same direction on a plane on which the plurality of lower electrodes is arranged.

18. The method of claim 17, wherein:

the third driving signal is a first threshold voltage driving signal sequentially applied to the plurality of lower electrodes.

19. The method of claim 17, wherein:

the third driving signal is second voltage driving signals increasing in a step-wise manner, and

wherein the second voltage driving signals are sequentially applied to the plurality of lower electrodes, respectively.

20. The method of claim 17, wherein:

the third driving signal is a third voltage driving signal simultaneously applied to the plurality of lower electrodes.

21. The method of claim 12, wherein:

the first alignment axis and the second alignment axis are substantially vertical to each other.

22. A display device comprising:

a display panel displaying an image;

a first polarizer disposed on the display panel, the first polarizer having a reflection axis and a transmission axis,

a first quarter-wave plate disposed on the first polarizer, the first quarter-wave plate having a first alignment axis,

a liquid crystal lens disposed on the first quarter-wave plate, wherein the liquid crystal lens includes liquid crystal molecules arranged according to a driving signal applied to the liquid crystal lens; and

a second quarter-wave plate disposed on the liquid crystal lens, the second quarter-wave plate having a second alignment axis

a second polarizer disposed on the second quarter-wave plate, the second polarizer having a penetration axis,

wherein the display device operates in a mirror mode, a three-dimensional (3D) mode, and a two-dimensional (2D) mode according to the driving signal applied to the liquid crystal lens,

wherein the first polarizer reflect first light having a polarization direction parallel to the reflection axis in the mirror mode, and transmits second light having a polarization direction parallel to the transmission axis in the 3D mode or the 2D mode, and

wherein the first alignment axis forms an angle of 45 degrees or 135 degrees with respect to the second alignment axis.