Optical design and optimization techniques for 3d light field displays

Patent metadata

Field	Value
Publication number	US-2022283431-A1
Application number	US-202017634734-A
Country	US
Kind code	A1
Filing date	Aug 12, 2020
Priority date	Aug 12, 2019
Publication date	Sep 8, 2022
Grant date	—

Abstract

Methods and frameworks for designing and optimizing of high-performance light field displays, such as integral imaging head-mounted displays, are disclosed. The disclosed techniques enable user-defined metrics for characterizing the performance and optimization of such systems. One design method relates to an integral-imaging based three-dimensional (3D) display system that includes an arrayed optics, an arrayed display device to produce a plurality of elemental images, a first reference plane representing a virtual central depth plane (CDP), a second reference plane representing a viewing window for viewing a reconstructed 3D scene, and an optical subsection representing a model of a human eye. The method includes tracing rays starting at the arrayed display device, through the arrayed optics, and to the optical subsection for each element of the arrayed display device and arrayed optics, and adjusting one or more parameters to obtain at least a first metric value within a predetermined value.

First claim

1 . A method for designing an integral-imaging (InI) based three-dimensional (3D) display system, the method comprising:
tracing a set of rays associated with a light field in the InI-based 3D system, the system including:
an arrayed optics,
an arrayed display device capable of producing a plurality of elemental images,
a first reference plane representing a virtual central depth plane (CDP) on which light rays emitted by a point source on the display converge to form an image point,
a second reference plane representing a viewing window for viewing a reconstructed 3D scene, and
an optical subsection representing a model of a human eye, wherein the tracing starts at the arrayed display device and is carried out through the arrayed optics and to the optical subsection for each element of the arrayed display device and arrayed optics; and
adjusting one or more parameters associated with the InI-based 3D system to obtain at least a first metric value within a predetermined value or range of values, wherein the first metric value corresponds to a ray directional sampling of the light field.

2 . The method of claim 1 , wherein the first metric value quantifies a deformation of ray footprint of a given ray bundle of the light field from its paraxial footprint.

3 . The method of claim 2 , wherein the first metric value is determined in accordance with a relative ratio of an average deviated distance between a real and a theoretical position of marginal rays on the second reference plane to a diagonal width of the paraxial footprint.

4 . The method of claim 1 , wherein the first metric value is determined based on a difference real positions of marginal rays on the viewing window obtained by ray tracing and their corresponding paraxial positions on the viewing window.

5 . The method of claim 1 , wherein adjusting the one or parameters associated with the InI-based 3D system is carried out to further obtain a second metric value within another predetermined value or range of values, wherein the second metric value corresponds to a ray positional sampling of the light field that accounts for deformations induced by neighboring elements of at least the arrayed optics.

6 . The method of claim 5 , wherein the second metric value is determined in accordance with an angular deviation between real and theoretical positions of a chief ray of a center object field measured from the second reference plane.

7 . The method of claim 5 , wherein the second metric value represents a global distortion measure.

8 . The method of claim 5 , wherein the second metric value is computed as a deviation of a center position of a virtual elemental image of the plurality of the elemental images on the virtual CDP from a paraxial position thereof.

9 . The method of claim 5 , wherein adjusting the one or parameters associated with the InI-based 3D system is carried out with respect to the ray positional sampling of the light field to further optimize imaging of each elemental image individually.

10 . The method of claim 1 , wherein the InI-based 3D system further includes an eyepiece positioned between the arrayed optics and the second reference plane, and wherein tracing the set of rays includes tracing the set of rays through the eyepiece.

11 . The method of claim 1 , wherein the arrayed display device is a microdisplay device.

12 . The method of claim 1 , wherein the arrayed optics comprises one or more lenslet arrays, each including a plurality of microlenses.

13 . The method of claim 1 , wherein the InI-based 3D system is an InI-based head-mounted display (InI-based HMD) system.

14 . The method of claim 1 , wherein the predetermined values, or range of values, for one or both of the first or the second metric are selected to achieve a particular image quality.

15 . The method of claim 1 , wherein the predetermined values, or range of values, for one or both of the first or the second metric represent a maxima or a minima that provides an optimum design criteria with respect to the first or the second metric.

16 . A method for improving design of an integral imaging optical system that includes a lenslet array that angularly samples directions of a light field producing an array of two-dimensional elemental images (EI), each representing a different perspective of a three-dimensional (3D), the method comprising:
determining a first metric corresponding to a ray directional sampling of the light field; determining a second metric corresponding to a ray positional sampling of the light field; and conducting a ray tracing operation for determining a design for the integral imaging optical system based on the first and the second metric.

17 . The method of claim 16 , wherein the ray tracing operation is conducted based on one or more constraints that include maintaining the first or the second metric at a corresponding value or range of value.

18 . The method of claim 16 , wherein the integral imaging optical system comprises an InI-based head-mounted display (InI-based HMD).

19 . A device, comprising:
a processor, and a memory comprising processor executable code, wherein upon execution by the processor cause the processor to:
trace a set of rays associated with a light field in the InI-based 3D system, wherein the system including:
an arrayed optics,
an arrayed display device capable of producing a plurality of elemental images,
a first reference plane representing a virtual central depth plane (CDP) on which light rays emitted by a point source on the display converge to form an image point,
a second reference plane representing a viewing window for viewing a reconstructed 3D scene, and
an optical subsection representing a model of a human eye, wherein the tracing starts at the arrayed display device and is carried out through the arrayed optics and to the optical subsection for each element of the arrayed display device and arrayed optics; and

adjust one or parameters associated with the InI-based 3D system to obtain at least a first metric value within a predetermined value or range of values, wherein the first metric value corresponds to a ray directional sampling of the light field.

20 . (canceled)

Assignees

• Univ Arizona

Inventors

• Hua Hong
• Huang Hekun

Classifications

• G02B27/0012 Primary

  Optical design, e.g. procedures, algorithms, optimisation routines · CPC title

• G02B30/10

  using integral imaging methods · CPC title

• G06T15/06

  Ray-tracing · CPC title

• G06F30/10

  Geometric CAD · CPC title

• H04N13/344

  with head-mounted left-right displays · CPC title