Optical systems with lens-based static foveation

Patent metadata

Field	Value
Publication number	US-12292572-B2
Application number	US-202318514710-A
Country	US
Kind code	B2
Filing date	Nov 20, 2023
Priority date	Sep 17, 2019
Publication date	May 6, 2025
Grant date	May 6, 2025

Abstract

An electronic device may include a display module that produces light having an image, a lens that directs the light to a waveguide, and a waveguide that directs the light to an eye box. The lens may produce a foveated image in the light by applying a non-uniform magnification to the image in the light. The non-uniform magnification may vary as a function of angle within a field of view of the lens. This may allow the foveated image to have higher resolution within the central region than in the peripheral region. Performing foveation using the lens maximizes the resolution of images at the eye box without increasing the size of the display module. Control circuitry on the device may apply a pre-distortion to the image that is an inverse of distortion introduced by the lens in producing the foveated image.

First claim

What is claimed is:

1. An electronic device comprising:
a projector configured to produce light that includes an image having a central region of pixels and a peripheral region of pixels;
a waveguide;
a lens configured to direct the light towards the waveguide; and
an input coupler configured to couple the light into the waveguide, wherein the waveguide is configured to propagate the light via total internal reflection, the lens being configured to apply a first magnification to the pixels in the peripheral region of the image and a second magnification to the pixels in the central region of the image, wherein the first magnification is greater than the second magnification.

2. The electronic device of claim 1 wherein the lens is further configured to stretch the image in a dimension by applying a non-uniform magnification to the light.

3. The electronic device of claim 1 further comprising an output coupler configured to couple the light out of the waveguide.

4. The electronic device of claim 1 wherein the lens has an optical axis, the lens is further configured to apply a third magnification at a first angle with respect to the optical axis and a fourth magnification at a second angle with respect to the optical axis, the first angle is smaller than the second angle, and the third magnification is less than the fourth magnification.

5. The electronic device of claim 4 wherein the lens is configured to produce a foveated image in the light.

6. The electronic device of claim 1 wherein the projector comprises an emissive display panel.

7. The electronic device of claim 1 wherein the projector comprises a spatial light modulator and a light source that is configured to illuminate the spatial light modulator to produce the light that includes the image.

8. The electronic device of claim 1 wherein the lens is a static lens.

9. An electronic device comprising:
a projector configured to display light that includes an image;
a lens configured to receive the light from the projector, wherein the lens comprises at least two lens elements and wherein an arrangement of the at least two lens elements configures the lens to statically impart different optical powers to different portions of the image; and
a waveguide configured to propagate the image via total internal reflection.

10. The electronic device of claim 9 wherein the lens is further configured to stretch the image in a dimension by statically imparting the different optical powers to the different portions of the image.

11. The electronic device of claim 9 wherein surfaces of the at least two lens elements configure the lens to statically impart the different optical powers to the different portions of the image.

12. The electronic device of claim 9 wherein the lens is further configured to produce a foveated image by statically imparting the different optical powers to the different portions of the image.

13. The electronic device of claim 12 wherein the optical powers vary as a function of angle within a field of view of the lens.

14. The electronic device of claim 12 wherein the projector is configured to apply a predistortion to the image in the light and wherein the predistortion is configured to compensate for a distortion associated with the different optical powers applied to the light by the lens.

15. The electronic device of claim 9 further comprising:
one or more processors configured to independently control intensities of light-emitting elements within the projector to mitigate for non-uniform intensity in the light.

16. A display system comprising:
a projector configured to produce light that includes an image, the image having a first dimension with a first magnitude and a second dimension with a second magnitude;
a waveguide configured to propagate the light via total internal reflection; and
a lens configured to direct the light towards the waveguide, wherein the lens is further configured to stretch the light only along the first dimension to produce a stretched image in the light.

17. The display system of claim 16 wherein the first dimension is a horizontal dimension of the image.

18. The display system of claim 16 , further comprising:
an input coupler configured to couple the light into the waveguide; and
an output coupler configured to couple the light out of the waveguide.

19. The display system defined in claim 18 , wherein the output coupler comprises volume holograms configured to diffract the light out of the waveguide.

Assignees

• Apple Inc

Inventors

• Bhakta Vikrant
• Kalinowski David A
• Choi Hyungryul
• Parkhill Nathanael D
• Melax Stanley K
• Cocilovo Byron R

Classifications

• G02B2027/0125

  Field-of-view increase by wavefront division · CPC title

• G02B2027/011

  comprising device for correcting geometrical aberrations, distortion · CPC title

• G02B2027/0163

  Electric or electronic control thereof · CPC title

• G02B2027/0147

  comprising a device modifying the resolution of the displayed image · CPC title

• G02B27/0172 Primary

  characterised by optical features · CPC title