Substrate-guided display with improved image quality

• US 20070159673A1
• Filed: 11/21/2006
• Published: 07/12/2007
• Est. Priority Date: 11/21/2005
• Status: Active Grant

• Current Assignee: Microvision, Inc.
• Original Assignee: Microvision, Inc.
• Inventors: Freeman, Mark, Powell, Karlton
• Granted Patent: US 7,736,006 B2
• Time in Patent Office: Days
• US Class Current: 359/19
• CPC Class Codes: G02B 2027/0118 comprising devices for improving the contrast of the display / brillance control visibility
• CPC Class Codes: G02B 2027/012 comprising devices for attenuating parasitic image effects
• CPC Class Codes: G02B 2027/0125 Field-of-view increase by wavefront division
• 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 27/0101 characterised by optical features G02B27/0172 takes precedence
• CPC Class Codes: G02B 27/0103 comprising holographic elements
• CPC Class Codes: G02B 27/102 for generating a colour image from monochromatic image signal sources
• CPC Class Codes: G02B 27/104 for use with scanning systems scanning systems G02B26/10
• CPC Class Codes: G02B 27/1086 operating by diffraction only
• CPC Class Codes: G02B 27/145 having sequential partially reflecting surfaces
• CPC Class Codes: G02B 27/149 using crossed beamsplitting surfaces, e.g. cross-dichroic cubes or X-cubes
• CPC Class Codes: G02B 27/28 for polarising used in stereoscopes G02B30/25
• CPC Class Codes: G02B 27/285 comprising arrays of elements, e.g. microprisms
• CPC Class Codes: G02B 27/4272 having plural diffractive elements positioned sequentially along the optical path
• CPC Class Codes: G02B 5/1814 structurally combined with one or more further optical elements, e.g. lenses, mirrors, prisms or other diffraction gratings G02B5/189 takes precedence
• CPC Class Codes: G02B 5/30 Polarising elements light-modulating devices with active elements G02F1/00
• CPC Class Codes: G02B 6/00 Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
• CPC Class Codes: G02B 6/0018 Redirecting means on the surface of the light guide
• CPC Class Codes: G02B 6/0028 Light guide, e.g. taper
• CPC Class Codes: G02B 6/0031 : Reflecting element, sheet or layer
• CPC Class Codes: G02B 6/0035 : provided on the surface of the light guide or in the bulk of it
• CPC Class Codes: G02B 6/0055 : Reflecting element, sheet or layer
• CPC Class Codes: G02B 6/0056 : for producing polarisation effects, e.g. by a surface with polarizing properties or by an additional polarizing elements
• CPC Class Codes: G02B 6/0068 : Arrangements of plural sources, e.g. multi-colour light sources
• CPC Class Codes: G02B 6/06 : the relative position of the fibres being the same at both ends, e.g. for transporting images

Abstract

A display system includes and image-guiding substrate with input and/or output structures configured to improve image quality.

Claims

1. An image-guiding substrate comprising:

an image output portion including a plurality of mirrors configured to receive propagated rays and launch the propagated rays toward a viewing region, each mirror having a partial reflectivity of substantially 1/Y*1/(X+1), wherein X is the number of mirrors remaining to be traversed by a portion of a ray not launched by the mirror and 1/Y is an occlusion.

2. The image-guiding substrate of claim 1 wherein Y is about 1, corresponding to a fully occluded viewing region.

3. The image-guiding substrate of claim 1 wherein Y is about 2, corresponding to an occlusion of about 0.5.

4. The image-guiding substrate of claim 1 wherein at least one of the mirrors includes a partial broadband reflector.

5. The image-guiding substrate of claim 1 wherein at least one of the mirrors includes a polarization-selective reflector.

6. The image guiding substrate of claim 1 wherein at least one of the mirrors includes a partial broadband reflector and a polarization-selective reflector.

7. The image-guiding substrate of claim 1 wherein at least one of the mirrors includes an angle-selective reflector.

8. The image-guiding substrate of claim 1 wherein at least one of the mirrors includes a polarization-selective reflector configured to sort odd-reflection rays from even-reflection rays.

9. The image guiding substrate of claim 1 further comprising:

substrate walls configured to rotate polarization 90 degrees each time a ray is reflected therefrom; and

wherein at least one of the mirrors includes a polarization-selective reflector configured to sort odd-reflection rays from even-reflection rays.

10. A method for displaying an image with an image-guiding substrate having an output portion with a number of output mirrors Z, comprising:

receiving a ray of light with the Wth mirror, wherein W is between 1 and Z, inclusive;

reflecting about 1/(X+1) of the power of the ray of light toward a viewing region, wherein X=Z−

W; and

passing about 1−

(1/X+1) of the power of the ray of light to the (W+1)th mirror, unless W=Z.

11. The method of claim 10 wherein the Wth mirror includes a partial broadband reflector.

12. The method of claim 10 wherein the Wth mirror includes a polarization-selective reflector.

13. The method of claim 10 wherein the Wth mirror includes a partial broadband reflector and a polarization-selective reflector.

14. The method of claim 10 wherein the Wth mirror includes an angle-selective reflector.

15. The method of claim 10 wherein the Wth mirror includes a polarization-selective reflector configured to sort odd-reflection rays from even-reflection rays.

16. The method of claim 10 further comprising:

prior to receiving the ray of light with the Wth mirror, guiding the ray of light in an image-guiding substrate having walls configured to rotate polarization of the ray 90 degrees each time the ray is reflected therefrom; and

wherein the Wth mirror includes a polarization-selective reflector configured to sort odd-reflection rays from even-reflection rays.

17. A display comprising:

a display engine operable generate an image and to provide rays of light corresponding to the image;

an image-guiding substrate configured to receive the rays of light from the display engine, propagate the rays to an output portion, and launch the rays of light from the output portion toward a viewing region;

wherein the output portion of the image-guiding substrate includes a plurality of output mirrors, the reflectivity of each output mirror selected to provide balanced optical power across the output portion.

18. The display of claim 17 wherein the reflectivity of each output mirror includes incidence angle selectivity.

19. The display of claim 17 wherein the reflectivity of each output mirror includes polarization angle selectivity.

20. The display of claim 17 wherein the reflectivity of each output mirror includes broadband partial reflectivity.

21. The display of claim 17 wherein the reflectivity of each output mirror includes spectral selectivity.

22. The display of claim 17 wherein the display engine includes an angle-mapped display engine.

23. The display of claim 17 wherein the display engine includes a location-mapped display engine and an ocular configured to convert location-mapped image information to the rays of light corresponding to the image.

24. A guiding-substrate display comprising:

a display engine operable to generate a modulated photonic output responsive to an electrical signal;

an input optical element configured to receive the modulated photonic output of the display engine and cooperate with the display engine to launch modulated photonic output having selected polarization;

an image relay slab configured to receive the modulated photonic output from the input optical element and guide the modulated photonic output from a proximal to a distal location; and

an output optical element configured to receive the modulated photonic output from the image relay slab and launch the modulated photonic output toward a viewing region.

25. The guiding-substrate display of claim 24 wherein the display engine is operable to produce modulated photonic output having the selected polarization.

26. The guiding-substrate display of claim 24 wherein the display engine includes a plurality of light sources operable to produce light having the selected polarization.

27. The guiding-substrate display of claim 24 wherein the input optical element is configured to impart the selected polarization on the launched modulated photonic output.

28. The guiding substrate display of claim 24 wherein the output optical element is configured to selectively launch the modulated photonic output toward the viewing region responsive to the polarization of the modulated photonic output.

29. The guiding substrate display of claim 24 wherein the output optical element is configured to selectively launch the modulated photonic output toward the viewing region responsive to the polarization of the modulated photonic output;

and

wherein the output optical element is further configured to modify the polarization of the modulated photonic output as the modulated photonic output traverses the output optical element.

30. The guiding substrate display of claim 24 wherein the image relay slab is configured to modify the polarization of the modulated photonic output as the modulated photonic output traverses the image relay slab.

31. The guiding substrate display of claim 24 wherein the input optical element and output optical element are integrated with the image relay slab.

32. A system operable to provide a viewable image comprising:

a controller operable to generate an electrical signal corresponding to a video image;

a display engine operable to produce a video image responsive to receiving the electrical signal; and

an image-guiding substrate aligned to receive the video image, the image-guiding substrate having an image output portion, the image output portion including a plurality of mirrors configured to receive propagated rays and launch the propagated rays toward a viewing region, each mirror having a partial reflectivity of substantially 1/Y*1/(X+1), wherein X is the number of mirrors remaining to be traversed by a portion of a ray not launched by the mirror and 1/Y is an occlusion

33. The system of claim 32 wherein the system includes a cellular telephone and the controller is operable to generate the electrical signal responsive to a received radio signal.

34. The system of claim 32 wherein the system includes a motor vehicle and the image-guided substrate is configured as a heads-up display.

35. The system of claim 32 wherein the system includes a television monitor and the image-guided substrate is configured as a flat panel display.