Optical device for use with scanned beam light sources
Substrate-guided relays that employ light guiding substrates to relay images from sources to viewers in optical display systems. The substrate-guided relays are comprised of an input coupler, an intermediate substrate, and an output coupler. In some embodiments, the output coupler is formed in a separate substrate that is coupled to the intermediate substrate. The output coupler may be placed in front of or behind the intermediate substrate, and may employ two or more partially reflective surfaces to couple light from the coupler. In some embodiments, the input coupler is coupled to the intermediate substrate in a manner that the optical axis of the input coupler intersects the optical axis of the intermediate substrate at a non-perpendicular angle.
1. An optical device that relays an image from an image source to a viewer, comprising:
an input coupler that receives a beam representing a portion of the image, creates multiple beams from the received beam and transmits the multiple beams to an intermediate substrate, wherein the input coupler is attached to the intermediate substrate so that an optical axis of the input coupler intersects an optical axis of the intermediate substrate at a non-perpendicular angle; and
an output coupler that receives the multiple beams from the intermediate substrate and outputs the multiple beams to the viewer, the output coupler attached to and external from the intermediate substrate.
2. The optical device of claim 1 , further comprising:
a partially reflective layer located between the input coupler and the intermediate substrate.
3. The optical device of claim 2 , wherein the partially reflective layer comprises a first area having a first reflectivity value and a second area having a second reflectivity value that differs from the first reflectivity value.
4. The optical device of claim 1 , further comprising:
a homogenization component that causes a number of light beams received by the output coupler to be greater than a number of light beams received by the input coupler.
5. The optical device of claim 4 , wherein the homogenization component is located inside the input coupler.
6. The optical device of claim 4 , wherein the homogenization component is located outside and adjacent to the input coupler.
7. The optical device of claim 4 , wherein the homogenization component is located inside the intermediate substrate.
8. The optical device of claim 4 , wherein the homogenization component is located outside and adjacent to the intermediate substrate.
9. The optical device of claim 1 , wherein the input coupler contains partially reflective surfaces that direct the transmitted beam to the intermediate substrate.
10. The optical device of claim 9 , wherein the reflectivity of the partially reflective surfaces is dependent on a wavelength of an incident beam.
11. The optical device of claim 9 , wherein the reflectivity of the partially reflective surfaces is dependent on a polarization of an incident beam.
12. The optical device of claim 9 , wherein the reflectivity of the partially reflective surfaces is dependent on an angle of incidence of an incident beam.
13. The optical device of claim 1 , wherein the input coupler is physically attached to the intermediate substrate at a surface parallel with the optical axis.
14. The optical device of claim 1 , wherein the input coupler is physically attached to the intermediate substrate at a surface perpendicular with the optical axis.
15. The optical device of claim 1 , wherein the intermediate substrate contains one or more partially reflective surfaces situated substantially parallel in relation to outer surfaces of the intermediate substrate, wherein the one or more partially reflective surfaces are configured to reflect incident beams of light having a first angle of incidence and transmit incident beams of light having a second angle of incidence that differs from the first angle of incidence.
16. The optical device of claim 1 , wherein the output coupler contains two or more partially reflective surfaces each having a similar partial reflection coating configured to output the beam from the output coupler and allow ambient beams of light to pass through the output coupler.