Infra-red and ultraviolet filtration in projection systems
View Patent ↗A method of generating a projection beam for projecting an image includes collimating the projection beam and filtering infra-red or ultraviolet radiation from the projection beam after the projection beam has been collimated.
1. A projection system comprising:
a collimating reflector for collecting light and directing a collimated projection beam; and
infra-red and ultraviolet filters for filtering said collimated projection beam, wherein said infra-red and ultraviolet filters are angled with respect to an optical axis, such that infra-red and ultraviolet light is reflected away from the optical axis.
2. The system of claim 1 , wherein said reflector is a parabolic reflector.
3. The system of claim 1 , further comprising:
a light-integrating tunnel; and
a lens for focusing said collimated projection beam, after filtering, into said light-integrating tunnel.
4. The system of claim 3 , wherein said lens is an aspheric condenser.
5. The system of claim 3 , further comprising a projection image generator optically coupled to said light-integrating tunnel.
6. The system of claim 5 , wherein said projection image generator is a Digital Mirror Device.
7. The system of claim 5 , wherein said projection image generator is a Liquid Crystal Display device.
8. The system of claim 1 , wherein said infra-red and ultraviolet light is reflected to a beam dump.
9. A projection system comprising:
means for collecting light and directing a collimated projection beam; and
means for filtering infra-red and ultraviolet radiation from said collimated projection beam, wherein means for filtering comprise infrared and ultraviolet filters that are angled with respect to an optical axis, such that infra-red and ultraviolet light is reflected away from the optical axis.
10. The system of claim 9 , wherein said means for collecting light and directing a collimated projection beam comprise a parabolic reflector.
11. The system of claim 9 , further comprising:
a light-integrating tunnel; and
means for focusing said collimated projection beam, after filtering, into said light-integrating tunnel.
12. The system of claim 9 , wherein said infra-red and ultraviolet light is reflected to a beam dump.
13. The system of claim 11 , wherein said means for focusing comprise an aspheric condenser.
14. The system of claim 11 , further comprising a projection image generator optically coupled to said light-integrating tunnel.
15. The system of claim 14 , wherein said projection image generator is a Digital Mirror Device.
16. The system of claim 14 , wherein said projection image generator is a Liquid Crystal Display device.
17. A method of generating a projection beam for projecting an image, said method comprising:
collimating said projection beam; and
filtering infra-red or ultraviolet radiation from said projection beam after said projection beam has been collimated, further comprising reflecting said infra-red or ultraviolet radiation away from an optical axis with infra-red and ultraviolet filters that are angled with respect to an optical axis.
18. The method of claim 17 , further comprising filtering both infra-red and ultraviolet radiation from said projection beam.
19. The method of claim 17 , further comprising collimating said projection beam with a reflector.
20. The method of claim 17 , further comprising, with said filters, reflecting said infra-red and ultraviolet light to a beam dump.
21. The method of claim 19 , further comprising using a parabolic reflector.