Reconstructing objects with display zero order light suppression

Patent metadata

Field	Value
Publication number	US-11360430-B2
Application number	US-202117478324-A
Country	US
Kind code	B2
Filing date	Sep 17, 2021
Priority date	Sep 17, 2020
Publication date	Jun 14, 2022
Grant date	Jun 14, 2022

Abstract

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 at an incident angle, a 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 diffract the portion of the light to form a holographic scene corresponding to the holographic data, and redirecting display zero order light away from the holographic scene to suppress the display zero order light in the holographic scene. The display zero order light includes reflected light from the display.

First claim

What is claimed is:

1. A method comprising:
providing an optical device comprising an optically diffractive component and an optically redirecting component;
diffracting light from the optically diffractive component to illuminate a display at an incident angle, a portion of the light illuminating display elements of the display that are spaced with gaps on the display;
modulating the display elements of the display with a hologram corresponding to holographic data, the hologram comprising respective control signals for modulating the display elements of the display;
using the display to diffract the portion of the light illuminating the display elements modulated with the hologram, such that display zero order light comes off the display with a larger deviation angle than the diffracted portion of the light, the display zero order light comprising reflected light from the display;
using the optically redirecting component to transmit the portion of the light diffracted by the display to form a holographic scene corresponding to the holographic data; and
using the optically redirecting component to redirect the display zero order light away from the holographic scene to suppress the display zero order light in the holographic scene by diffracting the display zero order light having a larger redirecting incident angle through the optically redirecting component with a substantially larger diffraction efficiency than the diffracted portion of the light, the larger redirecting incident angle corresponding to the larger deviation angle.

2. The method of claim 1 , wherein the diffracted portion of the light forms a reconstruction cone with a viewing angle, the incident angle is larger than a half of the viewing angle, and
the method further comprises configuring the hologram to modulate the display elements of the display 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.

3. The method of claim 1 , further comprising guiding the light to illuminate the display through the optically diffractive component formed on a substrate and configured to diffract the light out with the incident angle,
the guiding comprising 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.

4. The method of claim 1 , wherein using the optically redirecting component to redirect the display zero order light away from the holographic scene comprises diffracting the display zero order light away from the holographic scene by the optically redirecting component that is arranged downstream the display.

5. The method of claim 4 , wherein the optically diffractive component is formed on a first surface of a substrate facing to the display, and the optically redirecting component is formed on a second surface of the substrate that is opposite to the first surface.

6. The method of claim 5 , wherein the optically redirecting component is covered by a second substrate.

7. The method of claim 6 , wherein the display zero order light is p polarized before arriving at the second substrate, and the optically redirecting component is configured to diffract the display zero order light to be incident at a Brewster's angle on an interface between the second substrate and a surrounding medium, such that the display zero order light totally transmits through the second substrate.

8. The method of claim 7 , further comprising, before the display zero order light arrives at the second substrate, converting a polarization state of the display zero order light from s polarization to p polarization by an optically polarizing device arranged adjacent to the optically redirecting component with respect to the display.

9. The method of claim 1 , wherein the display zero order light is suppressed in the holographic scene with a light suppression efficiency of about 100%, and the light suppression efficiency is defined as a result of one minus a ratio between an amount of the display zero order light in the holographic scene with the suppression and an amount of the display zero order light in the holographic scene without the suppression.

10. An optical device comprising:
an optically diffractive component; and
an optically redirecting component,
wherein the optically diffractive component is configured to diffract light at an incident angle onto a display comprising a plurality of display elements spaced with gaps on the display, the display is configured to diffract a portion of the light illuminating the display elements, and the optically redirecting component is configured to transmit the portion of the light to form a holographic scene and to redirect display zero order light away from the holographic scene in a three-dimensional (3D) space to suppress the display zero order light in the holographic scene, the display zero order light comprising reflected light from the gaps on the display, and
wherein the optical device is configured such that the display zero order light is incident on the optically redirecting component at a redirecting incident angle larger than that of the diffracted portion of the light, and the optically redirecting component is configured to diffract the display zero order light through the optically redirecting component with a substantially larger diffraction efficiency than the diffracted portion of the light.

11. The optical device of claim 10 , wherein the optically diffractive component is formed on a first side of a substrate facing to the display, and the optically redirecting component is formed on a second side of the substrate that is opposite to the first side, and
wherein the optical device further comprises a second substrate covering the optically redirecting component.

12. The optical device of claim 11 , further comprising an optical absorber formed on at least one of a side surface of the substrate or a side surface of the second substrate, wherein the optical absorber is configured to absorb the display zero order light redirected by the optically redirecting component and reflected by an interface between the second substrate and a surrounding medium.

13. The optical device of claim 11 , further comprising an anti-reflective coating formed on the second substrate and being opposite to the optically redirecting component, the anti-reflective coating being configured to transmit the display zero order light redirected by the optically redirecting component.

14. The optical device of claim 11 , further comprising an optically polarizing device configured to convert a polarization state of the display zero order light from s polarization to p polarization before the display zero order light arrives at the second substrate, wherein the optically redirecting component is configured to diffract the display zero order light to be incident at a Brewster's angle on an interface between the second substrate and a surrounding medium, such that the display zero order light totally transmits through the second substrate.

15. The optical device of claim 14 , wherein the optical polarizing device comprises an optical retarder and a linear polarizer that are sequentially arranged together.

16. The optical device of claim 14 , wherein the optically polarizing device is arra

Assignees

• Pacific Light & Hologram Inc

Inventors

• Qaderi Kamran
• Hart Stephen John
• Hess Robert Alan
• Blackley Jonathan Seamus

Classifications

• G02B27/4272

  having plural diffractive elements positioned sequentially along the optical path · CPC title

• G03H1/2202 Primary

  Reconstruction geometries or arrangements · 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

• G02F1/13306

  Circuit arrangements or driving methods for the control of single liquid crystal cells (G02F1/132, G02F1/133382 take precedence) · CPC title

• G03H2001/0088

  for video-holography, i.e. integrating hologram acquisition, transmission and display · CPC title