Substrate-guided display with improved image quality
An image-guiding substrate including 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)], where 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.
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 (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 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 (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.
18. The system of claim 17 wherein the system includes a cellular telephone and the controller is operable to generate the electrical signal responsive to a received radio signal.
19. The system of claim 17 wherein the system includes a motor vehicle and the image-guided substrate is configured as a heads-up display.
20. The system of claim 17 wherein the system includes a television monitor and the image-guided substrate is configured as a flat panel display.