OPTICAL EXPANDER APPARATUS OF LARGE FIELD OF VIEW AND DISPLAY APPARATUS

Abstract

Disclosed are an optical expander apparatus, and a display apparatus. The optical expander apparatus comprises a waveguide plate, which in turn comprises: an in-coupling element to form first guided light by diffracting input light,a beam-split element to form second guided light by diffracting the first guided light,a first expander element to form third guided light by diffracting the second guided light,a second expander element to form fourth guided light by diffracting the first guided light, andan out-coupling element to form first output light by diffracting the third guided light, and to form second output light by diffracting the fourth guided light,wherein the out-coupling element is arranged to form combined output light by combining the first output light with the second output light,wherein the beam-split element has a same first grating period as the first expander element, and the second expander element has a different second grating period from the first expander element.

Description

Claims

1. An optical expander apparatus (EPE1), comprising a waveguide plate (SUB1), which in turn comprises: an in-coupling element (DOE1) to form first guided light (B1b) by diffracting input light (IN1),a beam-split element (DOEbs) to form second guided light (B1a) by diffracting the first guided light (B1b), to enhance an energy input to the first guided light (B1b) and the second guided light (B1a);a first expander element (DOE2a) to form third guided light (B2a) by diffracting the second guided light (B1a),a second expander element (DOE2b) to form fourth guided light (B2b) by diffracting the first guided light (B1b), andan out-coupling element (DOE3) to form first output light (OB3a) by diffracting the third guided light (B2a), and to form second output light (OB3b) by diffracting the fourth guided light (B2b),wherein the out-coupling element (DOE3) is arranged to form combined output light (OUT1) by combining the first output light (OB3a) with the second output light (OB3b),wherein the beam-split element (DOEbs) has a same first grating period (d2a) as the first expander element (DOE2a), and the second expander element (DOE2b) has a different second grating period (d2b) from the first expander element (DOE2a).

2. The optical expander apparatus (EPE1) of claim 1, wherein the beam-split element (DOEbs) has a third grating period different from the first grating period (d2a).

3. The optical expander apparatus (EPE1) of claim 1, wherein, in an instance in which the input light (IN1) corresponds to an input image (IMG0), and the width (Δφ) of the input image (IMG0) is greater than a predetermined limit (LIM1), the elements may be arranged to provide: red light (B1aP1,R) which -corresponds to a first corner point (P1) of the input image (IMG0), wherein grating vectors (m1V1, mbsVbs, m2aV2a, m2bV2b, m3aV3a, M3bV3b) of the elements (DOE1, DOEbs, DOE2a, DOE2b, DOE3) have been selected such that:the red light of the first corner point (P1) is guided from the in-coupling element (DOE1) to the out-coupling element (DOE3) via the beam-split element (DOEbs) and the second expander element (DOE2b),the red light of the first corner point (P1) is not guided from the in-coupling element (DOE1) to the out-coupling element (DOE3) via the beam-split element (DOEbs) and the first expander element (DOE2a).

4. The optical expander apparatus (EPE1) of claim 2, wherein, in an instance in which the input light (IN1) corresponds to an input image (IMG0), and the width (Δφ) of the input image (IMG0) is greater than a predetermined limit (LIM1), the elements may be arranged to provide: red light (B1aP1,R) which corresponds to a first corner point (P1) of the input image (IMG0), wherein grating vectors (m1V1, mbsVbs, m2aV2a, m2bV2b, m3aV3a, M3bV3b) of the elements (DOE1, DOEbs, DOE2a, DOE2b, DOE3) have been selected such that:the red light of the first corner point (P1) is guided from the in-coupling element (DOE1) to the out-coupling element (DOE3) via the beam-split element (DOEbs) and the second expander element (DOE2b),the red light of the first corner point (P1) is not guided from the in-coupling element (DOE1) to the out-coupling element (DOE3) via the beam-split element (DOEbs) and the first expander element (DOE2a).

5. The optical expander apparatus (EPE1) according to claim 1, wherein, in an instance in which the input light (IN1) corresponds to an input image (IMG0), and the width (Δφ) of the input image (IMG0) is greater than a predetermined limit (LIM1), the elements are arranged to provide: red light (B1aP1,R) which corresponds to a first corner point (P1) of the input image (IMG0),blue light (B1aP1,B) which corresponds to a second corner point (P2) of the input image (IMGO), wherein grating vectors (m1V1, mbsVbs, m2aV2a, m2bV2b, m3aV3a, m3bV3b) of the elements (DOE1, DOEbs, DOE2a, DOE2b, DOE3) have been selected such that:the red light of the first corner point (P1) is guided from the in-coupling element (DOE1) to the out-coupling element (DOE3) via the beam-split element (DOEbs) and the second expander element (DOE2b),the red light of the first corner point (P1) is not guided from the in-coupling element (DOE1) to the out-coupling element (DOE3) via the beam-split element (DOEbs) and the first expander element (DOE2a),the blue light of the second corner point (P2) is guided from the in-coupling element (DOE1) to the out-coupling element (DOE3) via the beam-split element (DOEbs) and the first expander element (DOE2a), andthe blue light of the second corner point (P2) is not guided from the in-coupling element (DOE1) to the out-coupling element (DOE3) via the beam-split element (DOEbs) and the second expander element (DOE2b).

6. The optical expander apparatus (EPE1) according to claim 2, wherein, in an instance in which the input light (IN1) corresponds to an input image (IMG0), and the width (Δφ) of the input image (IMG0) is greater than a predetermined limit (LIM1), the elements are arranged to provide: red light (B1aP1,R) which corresponds to a first corner point (P1) of the input image (IMG0),blue light (B1aP1,B) which corresponds to a second corner point (P2) of the input image (IMG0); wherein grating vectors (m1V1, mbsVbs, m2aV2a, m2bV2b, m3aV3a, M3bV3b) of the elements (DOE1, DOEbs, DOE2a, DOE2b, DOE3) have been selected such that:the red light of the first corner point (P1) is guided from the in-coupling element (DOE1) to the out-coupling element (DOE3) via the beam-split element (DOEbs) and the second expander element (DOE2b),the red light of the first corner point (P1) is not guided from the in-coupling element (DOE1) to the out-coupling element (DOE3) via the beam-split element (DOEbs) and the first expander element (DOE2a),the blue light of the second corner point (P2) is guided from the in-coupling element (DOE1) to the out-coupling element (DOE3) via the beam-split element (DOEbs) and the first expander element (DOE2a), andthe blue light of the second corner point (P2) is not guided from the in-coupling element (DOE1) to the out-coupling element (DOE3) via the beam-split element (DOEbs) and the second expander element (DOE2b).

7. The optical expander apparatus (EPE1) according to claim 1, wherein the first guided light (B1b) comprises light (B1bP0) which corresponds to a center point (P0) of the input image (IMG0),the second guided light (B1a) comprises light (B1aP0) which corresponds to the center point (P0) of the input image (IMG0),the third guided light (B2a) comprises light (B2aP0) which corresponds to the center point (P0) of the input image (IMG0),the fourth guided light (B2b) comprises light (B2bP0) which corresponds to the center point (P0) of the input image (IMG0), wherein the out-coupling element (DOE3) is arranged to: form a first output light beam (OB3a) by diffracting a light beam which corresponds to the center point (P0) of the input image (IMG0),form a second output light beam (OB3b) by diffracting the light beam which corresponds to the center point (P0) of the input image (IMG0),wherein the first output light beam (OB3a) and the second output light beam (OB3b) propagate in a direction (k0P0) which corresponds to the center point (P0).

8. The optical expander apparatus (EPE1) according to claim 2, wherein the first guided light (B1b) comprises light (B1bP0) which corresponds to a center point (P0) of the input image (IMG0),the second guided light (B1a) comprises light (B1aP0) which corresponds to the center point (P0) of the input image (IMG0),the third guided light (B2a) comprises light (B2aP0) which corresponds to the center point (P0) of the input image (IMG0),the fourth guided light (B2b) comprises light (B2bP0) which corresponds to the center point (P0) of the input image (IMG0), wherein the out-coupling element (DOE3) is arranged to:form a first output light beam (OB3a) by diffracting a light beam which corresponds to the center point (P0) of the input image (IMG0),form a second output light beam (OB3b) by diffracting the light beam which corresponds to the center point (P0) of the input image (IMG0), wherein the first output light beam (OB3a) and the second output light beam (OB3b) propagate in a direction (k0P0) which corresponds to the center point (P0).

9. The optical expander apparatus (EPE1) according to claim 1, wherein the in-coupling element (DOE1) is arranged to diffract the input light (IN1) such that the first guided light (B1b) comprises light of a center point (P0) of an input image (IMG0), and the beam-split element (DOEbs) is arranged to diffract the first guided light (B1b) such that the second guided light (B1a) comprises the light of the center point (P0) of the input image (IMG0), wherein the out-coupling element (DOE3) is arranged to diffract the third guided light (B2a) received from the first expander element (DOE2a) such that the first output light (OB3a) comprises the light of the center point (P0) of the input image (IMG0),wherein the out-coupling element (DOE3) is arranged to diffract the fourth guided light (B2b) received from the second expander element (DOE2b) such that the second output light (OB3b) comprises the light of the center point (P0) of the input image (IMG0),wherein the light of the center point (P0) in the first output light (OB3a) propagates in an axial direction (k3,P0), wherein the light of the center point (P0) in the second output light (OB3b) propagates in the same axial direction (k3,P0).

10. The optical expander apparatus (EPE1) according to claim 2, wherein the in-coupling element (DOE1) is arranged to diffract the input light (IN1) such that the first guided light (B1b) comprises light of a center point (P0) of an input image (IMG0), and the beam-split element (DOEbs) is arranged to diffract the first guided light (B1b) such that the second guided light (B1a) comprises the light of the center point (P0) of the input image (IMG0), wherein the out-coupling element (DOE3) is arranged to diffract the third guided light (B2a) received from the first expander element (DOE2a) such that the first output light (OB3a) comprises the light of the center point (P0) of the input image (IMG0),wherein the out-coupling element (DOE3) is arranged to diffract the fourth guided light (B2b) received from the second expander element (DOE2b) such that the second output light (OB3b) comprises the light of the center point (P0) of the input image (IMG0),wherein the light of the center point (P0) in the first output light (OB3a) propagates in an axial direction (k3,P0), wherein the light of the center point (P0) in the second output light (OB3b) propagates in the same axial direction (k3,P0).

11. The optical expander apparatus (EPE1) according to claim 1, comprising one or more optically isolating elements (ISO1) to prevent direct optical coupling between the first expander element (DOE2a) and the second expander element (DOE2b).

12. The optical expander apparatus (EPE1) according to claim 2, comprising one or more optically isolating elements (ISO1) to prevent direct optical coupling between the first expander element (DOE2a) and the second expander element (DOE2b).

13. A display apparatus (500) comprising an optical engine (ENG1) to form an primary input image (IMGO) and to convert the input primary image (IMG0) into a plurality of input light beams of the input light (IN1), the display apparatus (500) comprising the optical expander apparatus device (EPE1) to form light beams of combined output light (OUT1) by diffractively expanding the input light beams of the input light (IN1); and the optical expander apparatus (EPE1), comprising a waveguide plate (SUB1), which in turn comprises: an in-coupling element (DOE1) to form first guided light (B1b) by diffracting input light (IN1),a beam-split element (DOEbs) to form second guided light (B1a) by diffracting the first guided light (B1b), to enhance an energy input to the first guided light (B1b) and the second guided light (B1a);a first expander element (DOE2a) to form third guided light (B2a) by diffracting the second guided light (B1a),a second expander element (DOE2b) to form fourth guided light (B2b) by diffracting the first guided light (B1b), andan out-coupling element (DOE3) to form first output light (OB3a) by diffracting the third guided light (B2a), and to form second output light (OB3b) by diffracting the fourth guided light (B2b), wherein the out-coupling element (DOE3) is arranged to form combined output light (OUT1) by combining the first output light (OB3a) with the second output light (OB3b),wherein the beam-split element (DOEbs) has a same first grating period (d2a) as the first expander element (DOE2a), and the second expander element (DOE2b) has a different second grating period (d2b) from the first expander element (DOE2a).