Double pass illumination system
View Patent ↗A display device is disclosed, wherein the display device comprises a light source configured to emit light, a projection lens configured to transfer the light to a display surface, at least one other optical element, and a lens disposed optically between the light source and the projection lens, wherein the lens is configured to enable a first transfer of the light from the light source to the at least one other optical element, and the lens is configured to enable a second transfer of the light from the at least one other optical element to the projection lens.
1. A display device, comprising:
a light source configured to emit light;
a projection lens configured to transfer the light to a display surface;
a lens disposed optically between the light source and the projection lens;
a reflector configured to receive the light emitted by the light source via a first transfer through the lens and reflect the received light back to the lens without modulating the light to enable a second transfer of the light through the lens; and
an image-producing element including a microdisplay disposed optically between the lens and the projection lens such that the light interacts with the image-producing element optically downstream of the second transfer through the lens to produce an image.
2. The display device of claim 1 , wherein the lens is disposed optically between the light source and the reflector.
3. The display device of claim 1 , wherein the lens has a first portion configured to enable the first transfer of the light and a second portion configured to enable the second transfer of the light.
4. The display device of claim 3 , wherein the first portion and the second portion of the lens at least partially overlap.
5. The display device of claim 3 , wherein the first portion and the second portion of the lens do not overlap.
6. The display device of claim 1 , wherein the image-producing element is configured to reflect the light from the second transfer toward the projection lens.
7. The display device of claim 1 , wherein the reflector is configured to reflect the light received from a first portion of the lens toward a second portion of the lens.
8. The display device of claim 1 , wherein the reflector and the lens are configured to create a folded optical path.
9. The display device of claim 1 , wherein the display device is configured as a front projection display device.
10. The display device of claim 1 , wherein the display device is configured as a rear projection display device.
11. The display device of claim 1 , wherein the lens is a relay lens.
12. A display device, comprising:
a light source configured to emit light, wherein the light is unmodulated;
a redirecting element configured to redirect the unmodulated light;
a lens having a first portion configured to pass the unmodulated light emitted from the light source toward the redirecting element and a second portion configured to pass the unmodulated light received from the redirecting element; and
an image-producing element configured to receive the unmodulated light passed by the second portion of the lens;
wherein the image-producing element includes a microdisplay that is configured to produce an image from the unmodulated light received from the second portion of the lens.
13. The display device of claim 12 , wherein the first portion and the second portion of the lens at least partially overlap spatially.
14. The display device of claim 12 , wherein the first portion and the second portion of the lens do not overlap spatially.
15. The display device of claim 13 , wherein the redirecting element is a reflector configured to reflect light received from the first portion toward the second portion of the lens.
16. The display device of claim 12 , wherein the lens and the redirecting element are configured to create a folded optical path.
17. The display device of claim 12 , further comprising a projection lens disposed optically downstream of the lens, wherein the projection lens is configured to project the light to a display surface.
18. The display device of claim 12 , wherein the lens is a relay lens.
19. In an image display device, a method of displaying an image, comprising:
operating a light source to produce unmodulated light;
performing a first pass of the unmodulated light through a lens:
redirecting the unmodulated light;
performing a second pass of the unmodulated light through the lens; and
directing the unmodulated light onto an image-producing element after performing the second pass of the unmodulated light through the lens;
wherein the image-producing element includes a microdisplay that is configured to modulate the unmodulated light to produce an image.
20. The method of claim 19 , further comprising passing the light through a projection lens after performing the second pass of the light through the lens.
21. The method of claim 19 , wherein redirecting the light includes redirecting the light with a reflector.
22. The method of claim 19 , wherein the light passes through a first portion of the lens during the first pass and the light passes through a second portion of the lens during the second pass.
23. The method of claim 22 , wherein the first portion and the second portion of the lens at least partially overlap spatially.
24. The method of claim 22 , wherein the first portion and the second portion of the lens do not overlap spatially.
25. The method of claim 19 , further comprising directing the light through a folded optical path.
26. The method of claim 19 , wherein performing the first pass and the second pass through the lens comprises performing a first pass and a second pass of the light through a relay lens.