Reconstructing objects with display zero order light suppression
Methods, apparatus, devices, and systems for reconstructing three-dimensional objects with display zero order light suppression are provided. In one aspect, a method includes illuminating a display with light, a portion of the light illuminating display elements of the display, and modulating the display elements of the display with a hologram corresponding to holographic data to diffract the portion of the light to form a holographic scene corresponding to the holographic data, and to suppress display zero order light in the holographic scene. The display zero order light can include reflected light from the display.
1. A method comprising:
guiding light to illuminate a display, a first portion of the light illuminating display elements of the display;
modulating the display elements of the display with a hologram corresponding to holographic data to i) diffract the first portion of the light to form a holographic scene corresponding to the holographic data, and ii) suppress display zero order light in the holographic scene, the display zero order light comprising reflected light from the display, wherein the diffracted first portion of the light forms a reconstruction cone with a viewing angle, and guiding the light to illuminate the display with the light comprises guiding the light to illuminate the display at an incident angle that is larger than a half of the viewing angle; and
configuring the hologram such that the diffracted first portion of the light forms the reconstruction cone that is same as a corresponding reconstruction cone to be formed by the diffracted first portion of the light if the light is normally incident on the display,
wherein the holographic data comprises a respective phase for each of the display elements, the method further comprises configuring the hologram by adding a corresponding phase to the respective phase for each of the display elements, and the corresponding phases for the display elements are compensated by the incident angle such that the holographic scene corresponds to the respective phases for the display elements, and
wherein the corresponding phase for each of the display elements is expressed as:
Ø=2π( x cos θ+ y sin θ)/λ,
where Ø represents the corresponding phase for the display element, λ, represents a wavelength of the light, x and y represent coordinates of the display element in a global 3D coordinate system, and θ represents an angle corresponding to the incident angle.
2. The method of claim 1 , wherein illuminating the display with the light comprises a second portion of the light illuminates gaps between adjacent display elements, and
wherein the display zero order light comprises at least one member selected from the group consisting of: the second portion of the light reflected at the gaps of the display, the second portion of the light diffracted at the gaps of the display, reflected light from the display elements, and reflected right from a display cover covering the display.
3. The method of claim 1 , further comprising configuring the hologram such that the diffracted first portion of the light has at least one characteristic different from that of the display zero order light, and the at least one characteristic comprises a propagating direction away from the display.
4. The method of claim 1 , wherein guiding the light to illuminate the display comprises:
guiding the light by a beam splitter, and the diffracted first portion of the light and the display zero order light transmit through the beam splitter.
5. The method of claim 1 , wherein guiding the light to illuminate the display comprises guiding the light to illuminate the display at normal incidence.
6. The method of claim 1 , wherein configuring the hologram comprises:
moving a configuration cone with respect to the display with respect to a global 3D coordinate system, the configuration cone corresponding to the reconstruction cone and having an apex angle corresponding to the viewing angle of the reconstruction cone; and
generating the holographic data based on the moved configuration cone in the global 3D coordinate system.
7. The method of claim 6 , wherein moving the configuration cone with respect to the display in the global 3D coordinate system comprises rotating the configuration cone by a rotation angle with respect to a surface of the display with respect to the global 3D coordinate system, the rotation angle corresponding to the incident angle.
8. The method of claim 1 , further comprising blocking the display zero order light from appearing in the holographic scene.
9. The method of claim 8 , wherein a light suppression efficiency for the holographic scene is 100%.
10. The method of claim 8 , wherein blocking the display zero order light comprises guiding the display zero order light towards an optically blocking component arranged downstream the display.
11. The method of claim 10 , further comprising guiding the diffracted first portion of the light to transmit through the optically blocking component with a transmission efficiency to form the holographic scene.
12. The method of claim 11 , wherein the transmission efficiency is no less than a predetermined ratio.
13. The method of claim 10 , wherein the optically blocking component is configured to transmit a first light beam having an angle smaller than a predetermined angle and block a second light beam having an angle larger than the predetermined angle, and the predetermined angle is smaller than the incident angle and larger than the half of the viewing angle.
14. The method of claim 10 , wherein the optically blocking component comprises at least one member selected from the group consisting of a plurality of microstructures or nanostructures, a metamaterial layer, and an optically anisotropic film.
15. The method of claim 10 , wherein guiding the light to illuminate the display comprises guiding the light through an optically diffractive component on a substrate configured to diffract the light out with the incident angle.
16. The method of claim 15 , wherein guiding the light to illuminate the display comprises at least one member selected from the group consisting of: guiding the light through a waveguide coupler to the optically diffractive component; guiding the light through a coupling prism to the optically diffractive component; and guiding the light through a wedged surface of the substrate to the optically diffractive component.
17. The method of claim 15 , wherein the optically diffractive component is formed on a first surface of the substrate facing to the display, and the optically blocking component is formed on a second surface of the substrate that is opposite to the first surface.
18. An optical device comprising:
an optically diffractive component; and
an optically blocking component,
wherein the optically diffractive component is configured to diffract light at an incident angle to illuminate a display, with a portion of the light illuminating display elements of the display, and the optically blocking component is configured to block display zero order light in a holographic scene formed by the portion of the light diffracted by the display elements, the display zero order light comprising reflected light from the display,
wherein the display is configured to be modulated with a hologram corresponding to holographic data to diffract the portion of the light to form the holographic scene,
wherein the diffracted portion of the light forms a reconstruction cone with a viewing angle, and the light is illuminated on the display at an incident angle that is larger than a half of the viewing angle,
wherein the hologram is configured such that the diffracted portion of the light forms the reconstruction cone that is same as a corresponding reconstruction cone to be formed by the diffracted portion of the light if the light is normally incident on the display,
wherein the holographic data comprises a respective phase for each of the display elements, and the hologram is configured by adding a corresponding phase to the respective phase for each of the display elements, and the corresponding phases for the display elements are compensated by the incident angle such that the holographic scene corresponds to the respective phases for the display elements, and
wherein the corresponding phase for each of the display elements is expressed as:
Ø=2π( x cos θ+ y sin θ)/λ,
where Ø represents the corresponding phase for the display element, λ represents a wavelength of the light, x and y represent coordinates of the display element in a global 3D coordinate system, and θ represents an angle corresponding to the incident angle.
19. The optical device of claim 18 , wherein the optically blocking component is configured to transmit the diffracted portion of the light to form the holographic scene.
20. The optical device of claim 18 , wherein the optically blocking component is configured to transmit a first light beam having an angle smaller than a predetermined angle and block a second light beam having an angle larger than the predetermined angle, and the predetermined angle is smaller than the incident angle and larger than the half of the viewing angle.
21. The optical device of claim 18 , wherein the optically blocking component comprises a metamaterial layer or an optically anisotropic film.
22. The optical device of claim 18 , wherein the optically blocking component comprises a plurality of microstructures or nanostructures.
23. The optical device of claim 18 , further comprising a substrate having opposite sides, wherein the optically diffractive component and the optically blocking component are formed on the opposite sides of the substrate.
24. A system comprising:
a display comprising display elements separated with gaps on the display; and
an optical device arranged adjacent to the display, the optical device comprising:
an optically diffractive component; and
an optically blocking component,
wherein the optically diffractive component is configured to diffract light at an incident angle to illuminate a display, with a portion of the light illuminating display elements of the display, and the optically blocking component is configured to block display zero order light in a holographic scene formed by the portion of the light diffracted by the display elements, the display zero order light comprising reflected light from the display,
wherein the display is configured to be modulated with a hologram corresponding to holographic data to diffract the portion of the light to form the holographic scene,
wherein the diffracted portion of the light forms a reconstruction cone with a viewing angle, and the light is illuminated on the display at an incident angle that is larger than a half of the viewing angle,
wherein the hologram is configured such that the diffracted portion of the light forms the reconstruction cone that is same as a corresponding reconstruction cone to be formed by the diffracted portion of the light if the light is normally incident on the display,
wherein the holographic data comprises a respective phase for each of the display elements, and the hologram is configured by adding a corresponding phase to the respective phase for each of the display elements, and the corresponding phases for the display elements are compensated by the incident angle such that the holographic scene corresponds to the respective phases for the display elements, and
wherein the corresponding phase for each of the display elements is expressed as:
Ø=2π( x cos θ+ y sin θ)/λ,
where Ø represents the corresponding phase for the display element, λ represents a wavelength of the light, x and y represent coordinates of the display element in a global 3D coordinate system, and θ represents an angle corresponding to the incident angle.
25. A method of fabricating an optical device, the method comprising:
forming an optically diffractive component on a first side of a substrate; and
forming an optically blocking component on a second side of the substrate opposite to the first side,
wherein the optically diffractive component is configured to diffract light at an incident angle to illuminate a display, with a portion of the light illuminating display elements of the display, and the optically blocking component is configured to block display zero order light in a holographic scene formed by the portion of the light diffracted by the display elements, the display zero order light comprising reflected light from the display,
wherein the display is configured to be modulated with a hologram corresponding to holographic data to diffract the portion of the light to form the holographic scene,
wherein the diffracted portion of the light forms a reconstruction cone with a viewing angle, and the light is illuminated on the display at an incident angle that is larger than a half of the viewing angle,
wherein the hologram is configured such that the diffracted portion of the light forms the reconstruction cone that is same as a corresponding reconstruction cone to be formed by the diffracted portion of the light if the light is normally incident on the display,
wherein the holographic data comprises a respective phase for each of the display elements, and the hologram is configured by adding a corresponding phase to the respective phase for each of the display elements, and the corresponding phases for the display elements are compensated by the incident angle such that the holographic scene corresponds to the respective phases for the display elements, and
wherein the corresponding phase for each of the display elements is expressed as:
Ø=2π( x cos θ+ y sin θ)/λ,
where Ø represents the corresponding phase for the display element, λ represents a wavelength of the light, x and y represent coordinates of the display element in a global 3D coordinate system, and θ represents an angle corresponding to the incident angle.