HYBRID OPTICS FOR NEAR-EYE DISPLAYS

• US 20170147034A1
• Filed: 02/08/2017
• Published: 05/25/2017
• Est. Priority Date: 08/14/2013
• Status: Active Grant

• Current Assignee: NVIDIA Corporation
• Original Assignee: NVIDIA Corporation
• Inventors: Lanman, Douglas, Luebke, David
• Granted Patent: US 10,838,459 B2
• Time in Patent Office: Days
• CPC Class Codes: G02B 2027/011 comprising device for correcting geometrical aberrations, distortion
• CPC Class Codes: G02B 2027/0118 comprising devices for improving the contrast of the display / brillance control visibility
• CPC Class Codes: G02B 2027/0127 comprising devices increasing the depth of field
• CPC Class Codes: G02B 2027/014 comprising information/image processing systems
• CPC Class Codes: G02B 2027/015 involving arrangement aiming to get less bulky devices
• CPC Class Codes: G02B 27/0075 with means for altering, e.g. increasing, the depth of field or depth of focus
• CPC Class Codes: G02B 27/0172 characterised by optical features
• CPC Class Codes: G02B 3/0006 Arrays G02B3/02, G02B5/188 take precedence
• CPC Class Codes: G02B 3/0037 characterized by the distribution or form of lenses
• CPC Class Codes: G02B 30/27 involving lenticular arrays
• CPC Class Codes: G06F 1/163 Wearable computers, e.g. on a belt
• CPC Class Codes: G09G 3/003 to produce spatial visual effects

Abstract

A method for displaying a near-eye light field display (NELD) image is disclosed. The method comprises determining a pre-filtered image to be displayed, wherein the pre-filtered image corresponds to a target image. It further comprises displaying the pre-filtered image on a display. Subsequently, it comprises producing a near-eye light field after the pre-filtered image travels through a microlens array adjacent to the display, wherein the near-eye light field is operable to simulate a light field corresponding to the target image. Finally, it comprises altering the near-eye light field using at least one converging lens, wherein the altering allows a user to focus on the target image at an increased depth of field at an increased distance from an eye of the user and wherein the altering increases spatial resolution of said target image.

Claims

1. A method for displaying a near-eye light field display (NELD) image comprising:

displaying an image on a display, wherein said image corresponds to a target image;

producing a near-eye light field after said image travels through a microlens array disposed adjacent to said display, wherein said near-eye light field is operable to simulate a light field corresponding to said target image; and

altering said near-eye light field using at least one converging lens, wherein said altering allows a user to focus on said target image at an increased depth of field at an increased distance from an eye of said user.

2. The method of claim 1, wherein said image is a pre-filtered image, and further comprising:

determining said pre-filtered image to be displayed.

3. The method of claim 1, wherein at least one of said display, said converging lens, and said microlens array are curved in order to increase said perceived spatial resolution.

4. The method of claim 1, wherein said at least one converging lens is disposed between said microlens array and an expected position of an eye of said user and further is selected from the group consisting of:

a double convex lens, a plano-convex lens, a single optical element with a front surface being a converging lens and a rear surface being a microlens array, a cascade of converging lenses with varying focal lengths and pitches, and a cascade of microlens arrays.

5. The method of claim 1, wherein said microlens array comprises a plurality of microlenses and wherein at least one of said plurality of microlenses are electro-optically switchable.

6. The method of claim 1, wherein said determining is executed by a computer system, and further wherein said computer system is operable to be programmed with a virtual depth of field.

7. A system for displaying a NELD image comprising:

a display comprising a plurality of pixels;

a computer system coupled with said display and operable to cause said display to render a target image;

a microlens array disposed adjacent to said display and comprising a plurality of microlenses, wherein said microlens array is operable to produce a light field corresponding to said target image by altering light emitted by said display, wherein said display and said microlens array are disposed within a near-eye range of an observer; and

at least one converging lens disposed between said microlens array and an expected position of an eye of said observer.

8. The system of claim 7, wherein said at least one converging lens is operable to further alter said light field emitted from said microlens array in order to allow said observer to focus on said target image at an increased depth of field at an increased distance from an eye of said observer and to increase a spatial resolution of said target image.

9. The system of claim 8, wherein at least one of said display, said converging lens, and said microlens array are curved in order to increase perceived spatial resolution.

10. The system of claim 7, wherein said at least converging lens is selected from the group consisting of:

a double convex lens, a plano-convex lens, a single optical element with a front surface being a converging lens and a rear surface being a microlens array, a cascade of converging lenses with varying focal lengths and pitches, and a cascade of microlens arrays.

11. The system of claim 7, wherein said microlens array comprises a plurality of microlenses and wherein at least one of said plurality of microlenses are electro-optically switchable.

12. The system of claim 7, wherein said light field is operable to simulate a 3D object.

13. The system of claim 7, wherein said computer system is programmed with a with a virtual depth of field.

14. The system of claim 7, wherein said computer system is operable to be programmed with an eye-glasses prescription of said observer, wherein said eye-glasses prescription is used as a parameter in determining said virtual image distance, and wherein a method to program said computer system with said eye-glasses prescription is selected from the group consisting of:

manually entering said eye-glasses prescription, automatically determining said eye-glasses prescription, and interactively determining said eye-glasses prescription.

15. The system of claim 7, wherein said computer system is operable to be configured with a plurality of parameters, wherein said plurality of parameters control said light field, and wherein said plurality of parameters can be selected from a group consisting of:

dimension of virtual image, size of an eyebox, distance of said eyebox from said display, size of said display, number of pixels on said displays, size of said microlens array, focal length of lenses comprising said microlens array.

16. The system of claim 7, wherein said microlens array, said display and said at least one converging lens are operable to provide a virtual reality experience for said observer.

17. The system of claim 7, wherein said microlens array and said converging lens are placed in contact with each other.

18. An apparatus for displaying a NELD image comprising:

a curved display comprising a plurality of pixels, operable to display a pre-filtered image corresponding to a target image; and

a curved microlens array disposed adjacent to said display and comprising a plurality of microlenses, wherein said microlens array is operable to produce a light field corresponding to said target image by altering light emitted by said display, wherein said display and said microlens array are disposed within a near-eye range of an observer; and

at least one converging lens, wherein said at least one converging lens is operable to further alter said light field emitted from said microlens array.

19. The apparatus of claim 18, wherein said at least one converging lens is operable to alter said light field before entering an eye of said observer in order to allow said observer to focus on said target image at an increased depth of field at an increased distance from an eye of said observer and to increase a spatial resolution of said target image

20. The apparatus of claim 18, wherein said at least converging lens is disposed between said curved microlens array and an expected location of said eye of said observer and is selected from the group consisting of:

a double convex lens, a plano-convex lens, a single optical element with a front surface being a converging lens and a rear surface being a microlens array, a cascade of converging lenses with varying focal lengths and pitches, and a cascade of microlens arrays.

21. The apparatus of claim 18, wherein said display, said microlens array, and said at least one converging lens are components of a head mounted device.

22. The apparatus of claim 18, wherein said converging lens is curved.

23. The apparatus of claim 22, wherein said computer system is operable to be configured with a plurality of parameters, wherein said plurality of parameters control said light field, and wherein said plurality of parameters can be selected from a group consisting of:

dimension of virtual image, size of an eyebox, distance of said eyebox from said display, size of said display, number of pixels on said displays, size of said microlens array, focal length of lenses comprising said microlens array.

24. A method for displaying a near-eye light field display (NELD) image comprising:

determining a pre-filtered image to be displayed, wherein said pre-filtered image corresponds to a target image;

displaying said pre-filtered image on a display;

producing a near-eye light field after said pre-filtered image travels through a light field generating element, wherein said near-eye light field is operable to simulate a light field corresponding to said target image; and

altering said near-eye light field using at least one converging lens, wherein said altering allows a user to focus on said target image at an increased depth of field at an increased distance from an eye of said user and to increase spatial resolution of said target image.

25. The method of claim 24, wherein said light field generating element is a microlens array disposed adjacent to said display.

26. The method of claim 24, wherein said light field generating element is a stack of displays.