CN-122029473-A - Off-axis focal power image light guide system

Abstract

A near-eye display system includes a first correction optical element having a first power contribution operable to converge or diverge a real-world image-bearing light beam to a first focal distance in front of an eye box, and a second correction optical element disposed between the first correction optical element and the eye box. The second correction optical element has a spherical power contribution operable to converge or diverge the virtual and real world image-bearing beams to a second focus distance in front of the eyebox. The first correction optical element has a first correction center, and the second correction optical element has a second correction center.

Inventors

• ROBERT J. SCHULTZ
• Taylor W. Potter

Assignees

• 伊奎蒂公司

Dates

Publication Date

20260512

Application Date

20240818

Priority Date

20230818

Claims (20)

1. 1. A near-eye display system, comprising: a first corrective optical element having a first power contribution operable to converge or diverge the real-world image-bearing light beam to a first focal distance prior to the eyebox; A second correction optical element disposed between the first correction optical element and the eyebox, the second correction optical element having a spherical power contribution operable to converge or diverge the virtual image-bearing beam and the real-world image-bearing beam to a second focus distance in front of the eyebox, The first correction optical element has a first correction center and the second correction optical element has a second correction center.
2. 2. The near-eye display system of claim 1, wherein the first correction center is offset from a pupil distance position, wherein the offset at least partially causes a prism error.
3. 3. The near-eye display system of claim 2, wherein the second correction center is arranged to counteract the prismatic error.
4. 4. A near-eye display system as claimed in claim 3, wherein the second correction center is arranged opposite the first correction center with respect to the pupil position.
5. 5. The near-eye display system of claim 1, wherein the second correction optical element comprises a cylindrical power contribution operable to reduce optical aberrations associated with viewing real world objects and virtual objects at the second focal distance, wherein the second correction optical element comprises a correction axis.
6. 6. The near-eye display system of claim 5, wherein the correction axis is disposed above or below a horizontal line bisecting the first correction center.
7. 7. The near-eye display system of claim 1, wherein the first correction optical element comprises a liquid crystal layer operable to provide digital correction to the real-world image-bearing light beam.
8. 8. The near-eye display system of claim 1, wherein the second correction optical element comprises a liquid crystal layer operable to provide digital correction of the real-world image-bearing beam and the virtual image-bearing beam.
9. 9. The near-eye display system of claim 3, wherein the second corrective optical element comprises a wedge structure.
10. 10. The near-eye display system of claim 2, wherein the second correction optical element comprises a focal point of an optical surface that is offset to cancel the prismatic error.
11. 11. The near-eye display system of any one of claims 1-10, further comprising an image light guide comprising an outcoupling optical element having a spherical power contribution operable to converge or diverge a virtual image-bearing light beam in front of the eye box, wherein the outcoupling diffractive optical element comprises an output aperture center, and the output aperture center is offset from the pupil position.
12. 12. The near-eye display system of any one of claims 1-10, further comprising an image light guide comprising an outcoupling optical element having a spherical power contribution operable to converge or diverge a virtual image-bearing light beam prior to the eyebox, wherein the spherical power contribution of the outcoupling diffractive optical element is substantially equal to the spherical power contribution of the first corrective optical element.
13. 13. A method of manufacturing an image light guide system, comprising: Providing a first set of corrective optical elements having a spherical power contribution; Providing a collection of image light guides having spherical power contributions; selecting a first corrective optical element from the set; Selecting one image light guide from the set; customizing a second correction optical element having at least one of a spherical power contribution or a cylindrical power contribution; The image light guide is arranged in a stacked arrangement between the first correction optical element and the second correction optical element, wherein the second correction optical element is arranged between the image light guide and an eye-box.
14. 14. The method of claim 13, wherein the first set of corrective optical elements comprises a range of +2 diopters, 0 diopters, and-2 diopters spherical power contributions.
15. 15. The method of claim 14, wherein the set of image light guides comprises a range of +2 diopters, 0 diopters, and-2 diopters spherical power contributions.
16. 16. The method of claim 13, wherein the selected image light guide comprises a spherical power contribution substantially equal to a spherical power contribution of the selected first corrective optical element.
17. 17. The method of claim 13, wherein the selected first correction optical element comprises a first correction center and the second correction optical element comprises a second correction center, wherein the first correction center is offset from the pupil position and causes a prism error, and wherein the second correction center is arranged to cancel the prism error.
18. 18. An image light guide system for viewing a virtual object and a real world object within a common field of view, comprising: an image light guide having an inner surface and an outer surface, the image light guide being arranged to propagate a virtual image bearing light beam; a first correction optical element disposed between the image light guide and the real world object, the first correction optical element having a first spherical power contribution to a real world image-bearing light beam; An outcoupling optical element arranged along the image light guide, the outcoupling optical element having a second spherical power contribution to the virtual image-bearing beam, and A second correction optical element disposed between the image light guide and the eyebox, the second correction optical element having a third spherical power contribution to the virtual image-bearing beam and the real-world image-bearing beam, The first correction optical element has a first correction center and the second correction optical element has a second correction center.
19. 19. The image light guide system of claim 18, wherein the first correction center is offset from a pupil distance position, wherein the offset at least partially causes a prism error.
20. 20. The image light guide system of claim 19, wherein the second correction center is arranged to counteract the prism error.

Description

Off-axis focal power image light guide system Technical Field The present disclosure relates generally to augmented reality systems, and more particularly to an optical image light guide system having a diffractive optical element operable to convey image-bearing light to a viewer. Background Head Mounted Displays (HMDs) increasingly take the form of conventional glasses with less conspicuous optical elements for transmitting virtual image content in a manner that less obscures views of the surrounding environment. The image generator may be supported along the temple of the eye and the substantially transparent image light guide conveys the generated images as virtual images to the eye of the wearer, the virtual images being projected into a real world view of the wearer visible through the image light guide. The virtual image content may be transmitted along the image light guide as a set of angularly related light beams, where the relative angular directions of each light beam in two angular dimensions correspond to different locations (e.g., pixels) in the generated image. Typically, these beams are themselves collimated as if they correspond to a far point source located at a particular angular position within the field of view. Thus, when these collimated light beams are directed to overlapping locations within a common eye box, the wearer's eye treats the image generated in the eye box as a virtual image located at a distance approaching infinity. However, the real world objects of interest to the wearer may be much closer, requiring significant ocular accommodation to focus. Viewing virtual objects and real world objects that require different focus adjustments in the same scene may lead to eyestrain. Vision problems of the wearer's eyes caused by refractive errors, such as myopia, hyperopia, and astigmatism, can also pose challenges for low profile HMDs similar to conventional eyeglasses. If the wearer's traditional eyeglasses (including corrective lenses) must be removed to accommodate the low-profile HMD, the wearer's view of real world objects and virtual objects through the HMD may be compromised. Disclosure of Invention The present disclosure relates to one or more exemplary embodiments of an image light guide system that manages focus differences between real world objects and virtual objects presented to a viewer, manages vision problems affecting the focusing capabilities of a particular viewer, and reduces the eye requirements of a viewer when viewing the virtual object and the real world object within the same field of view. In an exemplary embodiment, the present disclosure provides a near-eye display system comprising a first correction optical element having a first power contribution operable to converge or diverge a real-world image-bearing beam to a first focal distance in front of an eye box, a second correction optical element disposed between the first correction optical element and the eye box, the second correction optical element having a spherical power contribution operable to converge or diverge a virtual image-bearing beam and a real-world image-bearing beam to a second focal distance in front of the eye box, the first correction optical element having a first correction center, the second correction optical element having a second correction center. In another exemplary embodiment, the present disclosure provides a method of manufacturing an image light guide system comprising providing a set of first correction optical elements having a spherical power contribution, providing a set of image light guides having a spherical power contribution, selecting one first correction optical element from the set, selecting one image light guide from the set, customizing a second correction optical element having at least one of a spherical power contribution or a cylindrical power contribution, and disposing the image light guide in a stacked arrangement between the first correction optical element and the second correction optical element, wherein the second correction optical element is disposed between the image light guide and an eye box. In another exemplary embodiment, the present disclosure provides an image light guide system for viewing virtual and real world objects within a common field of view, comprising an image light guide having an inner surface and an outer surface, the image light guide being arranged to propagate a virtual image-bearing light beam, a first correction optical element arranged between the image light guide and the real world object, the first correction optical element having a first spherical power contribution to the real world image-bearing light beam, an outcoupling optical element arranged along the image light guide, the outcoupling optical element having a second spherical power contribution to the virtual image-bearing light beam, and a second correction optical element arranged between the image light guide and the eye box, the second corre