Corrective optics for reducing fixed pattern noise in head mounted displays

1. An electronic display assembly comprising:

a display element having a first plurality of sub-pixels of a first type that is configured to emit light at a first wavelength and a second plurality of sub-pixels of a second type that is configured to emit light at a second wavelength, wherein two adjacent sub-pixels of the first plurality of sub-pixels are separated by a sub-pixel distance and two adjacent sub-pixels of the second plurality of sub-pixels are separated by a second sub-pixel distance; and

a corrective element coupled to the display assembly, the corrective element formed from a first grating profile that is stacked on top of a second grating profile,

the first grating profile including a plurality of first features configured to passively diffuse light emitted by the first plurality of sub-pixels such that an apparent distance between the two adjacent sub-pixels of the first type, viewed at a viewing distance away from the electronic display assembly, is less than the sub-pixel distance, and the plurality of first features is also configured to passively diffuse light emitted by the second plurality of sub-pixels less than the light emitted by the first plurality of sub-pixels, and

the second grating profile including a plurality of second features configured to passively diffuse light emitted by the second plurality of sub-pixels such that an apparent distance between the two adjacent sub-pixels of the second type, viewed at the viewing distance away from the electronic display assembly, is less than the second sub-pixel distance, and the plurality of second features is also configured to passively diffuse light emitted by the first plurality of sub-pixels.

2. The electronic display assembly of claim 1 , wherein the plurality of first features are selected from a group comprising one or more holes and one or more pillars.

3. The electronic display element of claim 1 , wherein the wherein the plurality of first features are arranged in a square packing.

4. The electronic display element of claim 1 , wherein the wherein the plurality of first features are arranged in a hexagonal packing.

5. The electronic display assembly of claim 1 , wherein a portion of the sub-pixel distance is dark space, and the plurality of first features are configured to correct for fixed pattern noise by blurring an image including the two adjacent sub-pixels of the first plurality of sub-pixels to mask the dark space between the two adjacent sub-pixels of the first plurality of sub-pixels.

6. The electronic display assembly of claim 1 , wherein the plurality of first features are configured to blur images of the two adjacent sub-pixels of the first plurality of sub-pixels by causing light emitted by each sub-pixel to appear as a plurality of closely spaced sub-pixels at the viewing distance.

7. The electronic display assembly of claim 1 , wherein the plurality of first features is configured to not diffuse light emitted by the second plurality of sub-pixels, and the plurality of second features is configured to not diffuse light emitted by the first plurality of sub-pixels.

8. The electronic display assembly of claim 1 , wherein the corrective element comprises a surface of the display element, and the plurality of first features is etched onto the surface of the display element using a single step process.

9. The electronic display assembly of claim 8 , wherein the plurality of first features is etched onto the surface of the display element using a nanoimprint lithography process.

10. The electronic display assembly of claim 1 , wherein the display element is a screen of a mobile device, and the corrective element is a film applied to a mobile device to reduce the appearance of defects on the screen.

11. An electronic display assembly comprising:

a display element having a plurality of sub-pixels of a first type that is configured to emit light at a first wavelength and a second plurality of sub-pixels of a second type that is configured to emit light at a second wavelength, wherein two adjacent sub-pixels of the first plurality of sub-pixels are separated by a sub-pixel distance and two adjacent sub-pixels of the second plurality of sub-pixels are separated by a second sub-pixel distance; and

a corrective element coupled to the display assembly, the corrective element formed from a first grating profile that is stacked on top of a second grating profile,

the first grating profile including a plurality of first features configured to passively diffuse light emitted by the first plurality of sub-pixels such that an apparent distance between the two adjacent sub-pixels of the first type, viewed at a viewing distance away from the electronic display assembly, is less than the sub-pixel distance, and the plurality of first features is also configured to passively diffuse light emitted by the second plurality of sub-pixels less than the light emitted by the first plurality of sub-pixels, and

the second grating profile including a plurality of second features configured to passively diffuse light emitted by the second plurality of sub-pixels such that an apparent distance between the two adjacent sub-pixels of the second type, viewed at the viewing distance away from the electronic display assembly, is less than the second sub-pixel distance, and the plurality of second features is also configured to passively diffuse light emitted by the first plurality of sub-pixels less than the light emitted by the second plurality of sub-pixels, and

wherein a pitch between adjacent features of the plurality of first features less is than the sub-pixel distance and the pitch between the adjacent features further satisfies the following equation: d f =3λD/d p , wherein d f represents the pitch between adjacent features of the corrective element, λ represents a wavelength of light emitted by the first plurality of sub-pixels, D represents the viewing distance, and d p represents the sub-pixel distance.

12. The electronic display assembly of claim 11 , wherein the first plurality of features are selected from a group comprising one or more holes and one or more pillars.

13. The electronic display assembly of claim 11 , wherein a portion of the sub-pixel distance is dark space, and the plurality of first features are configured to correct for fixed pattern noise by blurring an image including the two adjacent sub-pixels of the first plurality of sub-pixels to mask the dark space between the two adjacent sub-pixels of the first plurality of sub-pixels.

14. The electronic display assembly of claim 11 , wherein the plurality of first features are configured to blur images of the two adjacent sub-pixels of the first plurality of sub-pixels by causing light emitted by each sub-pixel to appear as a plurality of closely spaced sub-pixels at the viewing distance.

15. The electronic display assembly of claim 11 , wherein the corrective element comprises a surface of the display element, and the plurality of first features are etched onto the surface of the display element using a single step nanoprint lithography process.

16. The electronic display assembly of claim 11 , wherein the plurality of first features is arranged in a square packing.

17. The electronic display assembly of claim 11 , wherein the plurality of features is arranged in a hexagonal packing.

18. The electronic display assembly of claim 11 , wherein the plurality of first features is configured to not diffuse light emitted by the second plurality of sub-pixels, and the plurality of second features is configured to not diffuse light emitted by the first plurality of sub-pixels.