Beam deflector and 3-dimensional display device including the same

Patent metadata

Field	Value
Publication number	US-12078910-B2
Application number	US-202117324489-A
Country	US
Kind code	B2
Filing date	May 19, 2021
Priority date	Oct 30, 2020
Publication date	Sep 3, 2024
Grant date	Sep 3, 2024

Abstract

A beam deflector includes a first electrode layer including a plurality of line electrodes extending in a first direction and arranged parallel to each other in a second direction crossing the first direction; a second electrode layer separated from the first electrode layer by a predetermined distance to face the first electrode layer; and a deflection layer between the first electrode layer and the second electrode layer and having a plurality of optically anisotropic molecules controlled by an electric field formed between the first electrode layer and the second electrode layer. Each of the optically anisotropic molecules has an ellipse shape having a major axis and a minor axis, wherein the major axis is arranged to head for the first direction.

First claim

What is claimed is:

1. A beam deflector comprising:
a first electrode layer comprising a plurality of line electrodes, each of the plurality of line electrodes extending in a first direction and arranged parallel to each other in a second direction crossing the first direction;
a second electrode layer separated from the first electrode layer by a distance to face the first electrode layer; and
a deflection layer between the first electrode layer and the second electrode layer, the deflection layer comprising a plurality of optically anisotropic molecules controlled by an electric field formed between the first electrode layer and the second electrode layer, wherein
each of the plurality of optically anisotropic molecules has an ellipse shape having a major axis and a minor axis, wherein the major axis of each of the plurality of optically anisotropic molecules is arranged to head for the first direction.

2. The beam deflector of claim 1 , wherein the major axis of each of the plurality of optically anisotropic molecules is arranged to be inclined by a first angle θ 1 with respect to a central axis extending in the first direction, and the first angle θ 1 is in a range of −5°≤θ 1 ≤5°.

3. The beam deflector of claim 1 , wherein the major axis of each of the plurality of optically anisotropic molecules is inclined by a second angle θ 2 in a third direction perpendicular to both the first direction and the second direction with respect to a central axis extending in the first direction.

4. The beam deflector of claim 3 , wherein the second angle θ 2 is in a range of −5°≤θ 2 ≤5°.

5. The beam deflector of claim 1 , further comprising a first alignment layer between the first electrode layer and the deflection layer, wherein
a plurality of first grooves are arranged on a surface of the first alignment layer at positions corresponding to the plurality of line electrodes, and
wherein the plurality of first grooves extend in a direction inclined by a first angle θ 1 in the second direction with respect to a central axis extending in the first direction in the plane that is parallel to the first direction and the second direction.

6. The beam deflector of claim 5 , wherein the plurality of optically anisotropic molecules are arranged in a line along a region corresponding to the plurality of first grooves.

7. The beam deflector of claim 5 , further comprising a second alignment layer between the second electrode layer and the deflection layer, wherein
a plurality of second grooves are arranged on a surface of the second alignment layer at positions corresponding to the plurality of line electrodes, and
wherein the plurality of second grooves extend in the direction inclined by the first angle θ 1 in the second direction with respect to the central axis extending in the first direction in the plane that is parallel to the first direction and the second direction.

8. The beam deflector of claim 7 , wherein the plurality of second grooves are provided to face the plurality of first grooves.

9. The beam deflector of claim 1 , wherein the distance between the first electrode layer and the second electrode layer is in a range from about 1.5 μm to about 6.0 μm.

10. The beam deflector of claim 1 , wherein a separation distance in the second direction between two adjacent line electrodes among the plurality of line electrodes is in a range from about 1.0 μm to about 6.0 μm.

11. The beam deflector of claim 1 , wherein the distance between the first electrode layer and the second electrode layer is equal to a separation distance in the second direction between two adjacent line electrodes among the plurality of line electrodes.

12. The beam deflector of claim 1 , wherein each of the plurality of optically anisotropic molecules has a positive-type dielectric anisotropy.

13. The beam deflector of claim 1 , wherein each of the plurality of optically anisotropic molecules comprises a liquid crystal molecule.

14. The beam deflector of claim 1 , wherein the second electrode layer has a flat plate shape facing all of the plurality of line electrodes.

15. A 3D display device comprising:
a light source configured to provide a coherent light;
a beam deflector configured to deflect light from the light source, the beam deflector comprising:
a first electrode layer comprising a plurality of line electrodes, each of the plurality of line electrodes extending in a first direction and arranged parallel to each other in a second direction crossing the first direction;
a second electrode layer separated from the first electrode layer by a distance to face the first electrode layer; and
a deflection layer between the first electrode layer and the second electrode layer, the deflection layer comprising a plurality of optically anisotropic molecules controlled by an electric field formed between the first electrode layer and the second electrode layer; and

a spatial light modulator configured to diffract incident light from the beam deflector to form a holographic image, wherein
each of the plurality of optically anisotropic molecules has an ellipse shape having a major axis and a minor axis, wherein the major axis of each of the plurality of optically anisotropic molecules is arranged to head for the first direction.

16. The 3D display device of claim 15 , wherein the major axis of each of the plurality of optically anisotropic molecules is arranged to be inclined by a first angle θ 1 with respect to a central axis extending in the first direction, and the first angle θ 1 is in a range of −5°≤θ 1 ≤5°.

17. The 3D display device of claim 15 , wherein the beam deflector further comprises a first alignment layer between the first electrode layer and the deflection layer,
wherein a plurality of first grooves are arranged on a surface of the first alignment layer at positions corresponding to the plurality of line electrodes, and
wherein the plurality of first grooves extend in a direction inclined by a first angle θ 1 in the second direction with respect to a central axis in the first direction in the plane that is parallel to the first direction and the second direction.

18. The 3D display device of claim 17 , wherein the plurality of optically anisotropic molecules are arranged in a line along a region corresponding to the plurality of first grooves.

19. The 3D display device of claim 15 , further comprising:
an eye tracking sensor configured to sense positions of left and right eyes of a viewer; and
a controller configured to control the beam deflector based on the sensed positions of the left and right eyes of the viewer.

20. The 3D display device of claim 15 , further comprising a light guide unit between the light source and the spatial light modulator, the light guide unit being configured to enlarge the coherent light provided from the light source to fit a size of the spatial light modulator.

Assignees

• Samsung Electronics Co Ltd

Inventors

• Won Kanghee
• Kim Young
• An Jungkwuen
• Lee Hongseok

Classifications

• G02F1/292

  by controlled diffraction or phased-array beam steering (controlled diffraction for optical switching G02F1/31) · CPC title

• G02F1/134381

  Hybrid switching mode, i.e. for applying an electric field with components parallel and orthogonal to the substrates · CPC title

• G02F1/13706

  the liquid crystal having positive dielectric anisotropy · CPC title

• G02F1/133776

  having structures locally influencing the alignment, e.g. unevenness · CPC title

• G03H1/0005

  Adaptation of holography to specific applications (holographic optical element G02B5/32; holographic scanner G02B26/106; recognition using holographic mask G06V10/88; holographic memories G11B7/0065, G11C13/042) · CPC title