Geometric phase optical element and three-dimensional display apparatus including the same

Patent metadata

Field	Value
Publication number	US-11635633-B2
Application number	US-202017036837-A
Country	US
Kind code	B2
Filing date	Sep 29, 2020
Priority date	Mar 24, 2020
Publication date	Apr 25, 2023
Grant date	Apr 25, 2023

Abstract

A geometric phase optical element and a three-dimensional display apparatus including the same are provided. The geometric phase optical element includes: a liquid crystal layer; a first electrode on a surface of the liquid crystal layer; and a second electrode on another surface of the liquid crystal layer, wherein, when no voltage is applied to the first and second electrodes, the liquid crystal layer is configured such that a phase difference according to an arrangement of the liquid crystal is π and light transmitted through the liquid crystal layer is diffracted by a first deflection angle, and when a first voltage that causes the phase difference according to the arrangement of the liquid crystal to become π/2 is applied to the first and second electrodes, the liquid crystal layer is configured such that the light transmitted through the liquid crystal layer is diffracted by a second deflection angle.

First claim

What is claimed is:

1. A geometric phase optical element comprising:
a liquid crystal layer in which a liquid crystal is arranged and through which light is transmitted;
a first electrode on a surface of the liquid crystal layer; and
a second electrode on another surface of the liquid crystal layer,
wherein, when no voltage is applied to the first electrode and the second electrode, a phase difference, between first light having a first polarization state and second light having a second polarization state perpendicular to the first polarization state, according to an arrangement of the liquid crystal is π and the transmitted light is diffracted by a first deflection angle,
wherein, when a first voltage is applied to the first electrode and the second electrode, the phase difference according to the arrangement of the liquid crystal is π/2 and the transmitted light is diffracted by a second deflection angle,
wherein, when a second voltage is applied to the first electrode and the second electrode, the phase difference according to the arrangement of the liquid crystal is 0 and the transmitted light is diffracted by a third deflection angle,
wherein the first deflection angle is larger than the second deflection angle, and
wherein the second deflection angle is larger than the third deflection angle.

2. The geometric phase optical element of claim 1 , wherein when no voltage is applied to the first and second electrode, the first deflection angle satisfies the following equation:
sin θ 1 =2λ/ p,

wherein θ 1 indicates the first deflection angle, λ indicates a wavelength of the transmitted light, and p indicates a pitch corresponding to a liquid crystal arrangement cycle of the liquid crystal layer.

3. The geometric phase optical element of claim 1 , wherein the second deflection angle satisfies the following equation:
sin θ 2 =(λ/ p ),

wherein θ 2 indicates the second deflection angle, λ indicates a wavelength of the transmitted light, and p indicates a pitch corresponding to a liquid crystal arrangement cycle of the liquid crystal layer.

4. The geometric phase optical element of claim 1 , wherein the third deflection angle is 0.

5. The geometric phase optical element of claim 1 , wherein, when the first voltage is applied and incident light is left-handed circularly polarized light, the transmitted light diverges.

6. The geometric phase optical element of claim 5 , wherein the transmitted light has a phase difference of φ+π/4 with respect to the incident light, wherein φ indicates an angle between a direction of a liquid crystal arrangement cycle of the liquid crystal layer and a crystalline axis of the arrangement of the liquid crystal.

7. The geometric phase optical element of claim 1 , wherein, when the first voltage is applied and incident light is right-handed circularly polarized light, the transmitted light converges.

8. The geometric phase optical element of claim 7 , wherein the transmitted light has a phase difference of φ−π/4 with respect to the incident light, wherein φ indicates an angle between a direction of a liquid crystal arrangement cycle of the liquid crystal layer and a crystalline axis of the arrangement of the liquid crystal.

9. A geometric phase optical element structure comprising a plurality of geometric phase optical elements of claim 1 .

10. The geometric phase optical element structure of claim 9 , wherein, when the number of the plurality of geometric phase optical elements is N, the number of different deflection angles of light diffracted by the geometric phase optical elements is 3 N −N+1.

11. The geometric phase optical element of claim 1 , wherein the liquid crystal layer comprises at least one from among an electrically controlled birefringence (ECB) mode, a vertical alignment (VA) mode, a hybrid mode, and a twisted nematic (TN) mode.

12. A three-dimensional display apparatus comprising:
a light source;
a light guide plate configured to guide a beam incident from the light source;
at least one geometric phase optical element configured to change a deflection angle of light incident from the light guide plate; and
a spatial light modulator configured to form a hologram image using light transmitted through the at least one geometric phase optical element,
wherein the at least one geometric phase optical element comprises a liquid crystal layer in which a liquid crystal is arranged and through which the incident light is transmitted, a first electrode on a surface of the liquid crystal layer, and a second electrode on another surface of the liquid crystal layer,
wherein, when no voltage is applied to the first electrode and the second electrode, a phase difference, between first light having a first polarization state and second light having a second polarization state perpendicular to the first polarization state, according to an arrangement of the liquid crystal is π and light transmitted through the liquid crystal layer is diffracted by a first deflection angle,
wherein, when a first voltage is applied to the first electrode and the second electrode, the phase difference according to the arrangement of the liquid crystal is π/2 and the transmitted light is diffracted by a second deflection angle,
wherein, when a second voltage is applied to the first electrode and the second electrode, the phase difference according to the arrangement of the liquid crystal is 0 and the transmitted light is diffracted by a third deflection angle,
wherein the first deflection angle is larger than the second deflection angle, and
wherein the second deflection angle is larger than the third deflection angle.

13. The three-dimensional display apparatus of claim 12 , wherein the first deflection angle satisfies the following equation:
sin θ 1 =2λ/ p,

wherein θ 1 indicates the first deflection angle, λ indicates a wavelength of the transmitted light, and p indicates a pitch corresponding to a liquid crystal arrangement cycle of the liquid crystal layer.

14. The three-dimensional display apparatus of claim 12 , wherein the second deflection angle satisfies the following equation:
sin θ 2 =(λ/ p ),

wherein θ 2 indicates the second deflection angle, λ indicates a wavelength of the transmitted light, and p indicates a pitch corresponding to a liquid crystal arrangement cycle of the liquid crystal layer.

15. The three-dimensional display apparatus of claim 12 , wherein the third deflection angle is 0.

16. The three-dimensional display apparatus of claim 12 , wherein, when the first voltage is applied and the incident light is left-handed circularly polarized light, the transmitted light diverges.

17. The three-dimensional display apparatus of claim 16 , wherein the transmitted light has a phase difference of φ+π/4 with respect to the incident light, wherein φ indicates an angle between a direction of a liquid crystal arrangement cycle of the liquid crystal layer and a crystalline axis of the arrangement of the liquid crystal.

18. The three-dimensional display apparatus of claim 12 , wherein, when the first voltage is applied and the incident light is right-handed circularly polarized light, the transmitted light converges.

19. The three-dimensional display apparatus of claim 18 , wherein the transmitted light has a phase difference of φ−π/4 with respect to the incident light, wherein φ indicates an angle between a direction of a liquid crystal arrangement cycle of the liquid crystal layer and a crystalline axis of the arrangement of the liquid crystal.

20. The t

Assignees

• Samsung Electronics Co Ltd

Inventors

• Kim Young
• Kwon Soonbum
• Song Byonggwon
• An Jungkwuen
• Won Kanghee
• Lee Hongseok
• Hong Jong-Young

Classifications

• G02B30/25 Primary

  using polarisation techniques · CPC title

• G02F1/133528

  Polarisers · CPC title

• G02F1/133538

  with spatial distribution of the polarisation direction · CPC title

• G02B5/3016 Primary

  involving passive liquid crystal elements (optical properties of liquid crystals G02F1/0063; polarising elements associated with active liquid crystal devices G02F1/133528) · CPC title

• G02F1/291 Primary

  Two-dimensional analogue deflection · CPC title