Light projection system including an optical assembly for correction of differential distortion

Patent metadata

Field	Value
Publication number	US-11002969-B2
Application number	US-201916242974-A
Country	US
Kind code	B2
Filing date	Jan 8, 2019
Priority date	Jan 25, 2018
Publication date	May 11, 2021
Grant date	May 11, 2021

Abstract

A light projection system includes a light source configured to emit image light and an optical assembly configured to provide positive optical power to the image light and optically correct the image light. The optical assembly comprises a plurality of optical elements configured to correct differential distortion related to the image light across a field of view (FOV) within a threshold amount. The differential distortion is corrected based in part on asymmetry of the plurality of optical elements relative to an optical axis shared by the plurality of optical elements.

First claim

What is claimed is:

1. A light projection system comprising:
a light source configured to emit image light; and
an optical assembly configured to provide a positive optical power to the image light and optically correct the image light, the optical assembly comprising a plurality of optical elements configured to correct differential distortion related to the image light across a field of view (FOV) within a threshold amount based on an optical asymmetry of the plurality of optical elements relative to an optical axis shared by the plurality of optical elements, the optical asymmetry achieved by at least decentering one or more optical elements of the plurality of optical elements relative to the optical axis.

2. The light projection system of claim 1 , wherein the light projection system is part of a near-eye-display (NED).

3. The light projection system of claim 1 , wherein the light source is a strip source.

4. The light projection system of claim 3 , wherein the strip source is selected from a group consisting of a linear array of micro-light emitting diodes, and a linear array of vertical cavity emitting lasers.

5. The light projection system of claim 1 , further comprising a scanning mirror configured to scan the optically corrected image light in at least one dimension of the FOV.

6. The light projection system of claim 1 , wherein the plurality of optical elements having the optical asymmetry relative to the optical axis includes a plurality of rotationally symmetric elements, wherein at least one of the rotationally symmetric elements is decentered relative to the optical axis.

7. The light projection system of claim 1 , wherein the plurality of optical elements having the optical asymmetry relative to the optical axis includes one or more non-rotationally symmetric elements.

8. The light projection system of claim 7 , wherein the one or more non-rotationally symmetric elements include at least one anamorphic surface.

9. The light projection system of claim 1 , wherein the plurality of optical elements having the optical asymmetry relative to the optical axis includes one or more non-rotationally symmetric elements decentered relative to the optical axis.

10. The light projection system of claim 1 , wherein the plurality of optical elements having the optical asymmetry relative to the optical axis includes a plurality of rotationally symmetric elements, wherein at least one of the rotationally symmetric elements is tilted relative to the optical axis.

11. The light projection system of claim 1 , wherein the optical assembly is configured to correct the differential distortion based on the optical asymmetry of the plurality of optical elements by propagating the image light using an off-axis field segment of the plurality of optical elements.

12. The light projection system of claim 1 , wherein the plurality of optical elements having the optical asymmetry relative to the optical axis is configured to correct the differential distortion across at least one of a long axis and a short axis of the FOV.

13. The light projection system of claim 1 , wherein the plurality of optical elements includes at least one convex lens and at least one concave lens.

14. A near-eye display (NED) comprising:
a light source configured to emit image light;
an optical assembly configured to provide a positive optical power to the image light and optically correct the image light, the optical assembly comprising a plurality of optical elements configured to correct differential distortion related to the image light across a field of view (FOV) within a threshold amount based on an optical asymmetry of the plurality of optical elements relative to an optical axis shared by the plurality of optical elements, the optical asymmetry achieved by at least decentering one or more optical elements of the plurality of optical elements relative to the optical axis; and
a scanning mirror configured to scan the optically corrected image light in at least one dimension of the FOV and direct the scanned image light to an eye-box of the NED corresponding to a location of a user's eye.

15. The NED of claim 14 , wherein the plurality of optical elements having the optical asymmetry relative to the optical axis includes a plurality of rotationally symmetric elements, wherein at least one of the rotationally symmetric elements is decentered relative to the optical axis.

16. The NED of claim 14 , wherein the plurality of optical elements having the optical asymmetry relative to the optical axis includes one or more non-rotationally symmetric elements.

17. The NED of claim 16 , wherein the one or more non-rotationally symmetric elements include at least one anamorphic surface.

18. The NED of claim 14 , wherein the plurality of optical elements having the optical asymmetry relative to the optical axis includes one or more non-rotationally symmetric elements decentered relative to the optical axis.

19. The NED of claim 14 , wherein the plurality of optical elements having the optical asymmetry relative to the optical axis includes a plurality of rotationally symmetric elements, wherein at least one of the rotationally symmetric elements is tilted relative to the optical axis.

20. The NED of claim 14 , wherein the optical assembly is configured to correct the differential distortion based on the optical asymmetry of the plurality of optical elements by propagating the image light using an off-axis field segment of the plurality of optical elements.

Assignees

• Facebook Tech Llc

Inventors

• Schaub Michael Patrick
• Taylor Byron
• Fu Yijing

Classifications

• G02B27/0172 Primary

  characterised by optical features · CPC title

• G02B2027/011

  comprising device for correcting geometrical aberrations, distortion · CPC title

• G02B2027/0178

  Eyeglass type (eyeglass details G02C) · CPC title

• G02B26/10

  Scanning systems · CPC title

• G02B26/0816 Primary

  by means of one or more reflecting elements · CPC title