HOLOGRAPHIC WIDE ANGLE DISPLAY

• US 20140104665A1
• Filed: 04/24/2013
• Published: 04/17/2014
• Est. Priority Date: 04/25/2012
• Status: Active Grant

• Current Assignee: DigiLens Inc, Rockwell Collins, Inc. (Rtx Corporation)
• Original Assignee: DigiLens Inc
• Inventors: Popovich, Milan Momcilo, Waldern, Jonathan David, Hendrick, Wyatt L., Stanley, James H., Grant, Alastair John
• Granted Patent: US 9,341,846 B2
• Time in Patent Office: Days
• US Class Current: 359/15
• CPC Class Codes: G02B 2027/0112 comprising device for genereting colour display
• CPC Class Codes: G02B 2027/0123 comprising devices increasing the field of view
• CPC Class Codes: G02B 2027/013 comprising a combiner of particular shape, e.g. curvature
• CPC Class Codes: G02B 2027/015 involving arrangement aiming to get less bulky devices
• CPC Class Codes: G02B 2027/0174 holographic
• CPC Class Codes: G02B 27/0081 with means for altering, e.g. enlarging, the entrance or exit pupil
• CPC Class Codes: G02B 27/0103 comprising holographic elements
• CPC Class Codes: G02B 27/0172 characterised by optical features
• CPC Class Codes: G02B 27/0176 characterised by mechanical features
• CPC Class Codes: G02B 30/34 Stereoscopes providing a stereoscopic pair of separated images corresponding to parallactically displaced views of the same object, e.g. 3D slide viewers
• CPC Class Codes: G02B 5/3083 Birefringent or phase retarding elements G02B5/3008, G02B5/3016 take precedence; systems for polarisation control G02B27/286; manufacturing phase modulating patterns by lithographic processes G03F7/001
• CPC Class Codes: G02B 5/32 Holograms used as optical elements
• CPC Class Codes: G02B 6/0018 Redirecting means on the surface of the light guide
• CPC Class Codes: G02B 6/0035 provided on the surface of the light guide or in the bulk of it
• CPC Class Codes: G02B 6/005 provided by one optical element, or plurality thereof, placed on the light output side of the light guide
• CPC Class Codes: G02B 6/0076 Stacked arrangements of multiple light guides of the same or different cross-sectional area
• CPC Class Codes: G03H 2001/2226 Edge lit holograms
• CPC Class Codes: G03H 2001/2239 Enlarging the viewing window

Abstract

Provided in one embodiment is an apparatus for displaying an image, comprising: an input image node configured to provide at least a first and a second image modulated lights; and a holographic waveguide device configured to propagate the at least one of the first and second image modulated lights in at least a first direction. The holographic waveguide device comprises: at least a first and second interspersed multiplicities of grating elements disposed in at least one layer, the first and second grating elements having respectively a first and a second prescriptions. The first and second multiplicity of grating elements are configured to deflect respectively the first and second image modulated lights out of the at least one layer into respectively a first and a second multiplicities of output rays forming respectively a first and second FOV tiles.

Claims

1. An apparatus for displaying an image, comprising:

an input image node configured to provide at least a first and a second image modulated lights; and

a holographic waveguide device configured to propagate the at least one of the first and second image modulated lights in at least a first direction, the holographic waveguide device comprising;

at least a first and second interspersed multiplicities of grating elements disposed in at least one layer, the first and second grating elements having respectively a first and a second prescriptions;

wherein the first and second image modulated lights are modulated respectively with first field of view (FOV) and second FOV image information;

wherein the first multiplicity of grating elements are configured to deflect the first image modulated light out of the at least one layer into a first multiplicity of output rays forming a first FOV tile, and the second multiplicity of grating elements are configured to deflect the second image modulated light out of the layer into a second multiplicity of output rays forming a second FOV tile.

2. The apparatus of claim 1, wherein the first and second multiplicities of the grating elements are tessellated in a predetermined pattern.

3. The apparatus of claim 1, wherein the first and second multiplicities of the grating elements are tessellated in a predetermined pattern and the predetermined pattern is at least one of a periodic pattern, a non-periodic pattern, a self-similar pattern, and randomly distributed pattern.

4. The apparatus of claim 1 wherein all elements in the first or second multiplicities of grating elements are configured to be switched into a diffracting state simultaneously.

5. The apparatus of claim 1, wherein at least one of the first and second multiplicities of the grating elements have a shape that comprises at least one of square, triangle and diamond.

6. The apparatus of claim 1, wherein elements of the first multiplicity of grating elements have a first geometry and elements of the second multiplicity of grating elements have a second geometry.

7. The apparatus of claim 1, wherein at least one of the first and second grating elements have at least two different geometries.

8. The apparatus of claim 1, wherein all grating elements in the at least one the layer are optimized for one wavelength.

9. The apparatus of claim 1, wherein at least one of the first and second grating elements in the at least one layer are optimised for at least two wavelengths.

10. The apparatus of claim 1, wherein at least one of the first and second grating elements have multiplexed prescriptions optimized for at least two different wavelengths

11. The apparatus of claim 1, wherein at least one of the first and second grating elements have multiplexed prescriptions optimized for at least two different diffraction efficiency angular bandwidths.

12. A device comprising the apparatus of claim 1, wherein the device is a part of a stereoscopic display in which the first and second image modulated light provides left and right eye perspective views.

13. A device comprising the apparatus of claim 1, wherein the device is a part of at least one of HMD, HUD, and HDD.

14. The apparatus of claim 1, wherein at least one of the first and second multiplicities of the grating elements have a diffraction efficiency that is spatially dependent.

15. The apparatus of claim 1, wherein the image modulated light from at least one grating element of a given prescription is present within an exit pupil region bounded by the instantaneous aperture of the human eye pupil.

16. The apparatus of claim 1, wherein at least one of the first and second multiplicities of the grating elements are electrically switchable

17. A method of displaying an image, the method comprising:

(i) providing an apparatus comprising;

an input image node and a holographic waveguide device comprising (M×

N) interspersed multiplicities of grating elements, where M, N are integers;

(ii) generating image modulated light (I,J) input image node corresponding to field of view (FOV) tile (I,J), for integers 1≦

I≦

N and 1≦

J≦

M;

(iii) switching grating elements of prescription matching FOV tile (I,J) to their diffracting states;

(iv) illuminating grating elements of prescription matching FOV tile (I,J) with image modulated light (I,J); and

(v) diffracting the image modulated light I, J into FOV tile I, J.

18. The method of claim 17, further comprising repeating (ii)-(v) until achieving full FOV tiled.

19. The method of claim 17, further comprising sampling the input image into a plurality of angular intervals, each of the plurality of angular intervals having an effective exit pupil that is a fraction of the size of the full pupil.

20. The method of claim 17, further comprising improving the displaying of the image by modifying at least one of the following of the at least one grating lamina of at least one of the first and second optical substrates:

grating thickness, refractive index modulation, k-vector, surface grating period, and hologram-substrate index difference.