Light emitting diode projection system

A projection apparatus for forming video images, said projection apparatus comprising:

• at least one LED optical source having a predetermined étendue and spectral output;
• a digital device for selectively modulating light incident thereto, said digital device having a given étendue;
• at least one non-imaging optic for collecting substantially all of the light emitted by said at least one LED optical source and re-emitting it as a spatially uniform beam of substantially the same étendue as that of said LED optical source, said non-imaging optic having an entrance aperture, an exit aperture, and a nonrotationally symmetric cross-sectional shape that continuously enlarges from said entrance to said exit aperture, said at least one LED optical source being positioned at and fully across said entrance aperture so that said entrance aperture is substantially uniformly filled by said output of said LED optical source, said output of said at least one LED optical source being directed by said non-imaging optical shape to emerge from said exit aperture as a beam having substantially the same étendue as that of said at least one LED optical source but altered in angle and dimensions to substantially match the étendue of said digital device;
• a relay lens for imaging the near field from said non-imaging optic onto said digital device to form video images;
• a screen for viewing images formed thereon;
• and
• a projection lens for projecting said digital device onto said screen as said digital device is modulated so that video images formed thereon can be observed on said viewing screen,
• wherein said relay lens images the far field of said beam from said non-imaging optic into the aperture stop of said projection lens.

An illumination apparatus for providing an output beam that matches the &endue of a downstream application, said illumination apparatus comprising

• at least one LED optical source having a predetermined étendue and spectral output;
• and
• at least one solid non-imaging optic for collecting substantially all of the light emitted by said at least one LED optical source and re-emitting it as a spatially uniform beam of substantially the same étendue as that of said LED optical source, said non-imaging optic having an entrance aperture, an exit aperture, and a rotationally symmetric cross-sectional shape that continuously enlarges from said entrance to said exit aperture, said at least one LED optical source being air spaced from and fully across said entrance aperture so that (said entrance aperture is substantially uniformly filled by said output of said LED optical source, said output of said at least one LED optical source being directed by said non-imaging optical shape to emerge from said exit aperture as a beam having substantially the same étendue as that of said at least one LED optical source but altered in angle and dimensions to substantially match the étendue of the downstream application,
• wherein said at least one solid non-imaging optic comprises a first conical section beginning with said entrance aperture and a second section haying the shape of a CPC and ending with said exit aperture, said first conical section and said second CPC section transitioning at a cross-sectional location of said at least one non-imaging optic where they share common points of tangency so that said at least one solid non-imaging optic can efficiently utilize the output of an LED that is larger than it otherwise could be without said conical section.

An illumination apparatus for providing an output beam that matches the étendue of a downstream application, said illumination apparatus comprising

• at least two LED optical sources having a predetermined étendue and different spectral output beams;
• at least two non-imaging optics for collecting substantially all of the light emitted by said at least two LED optical source and re-emitting it as a beam of substantially the same étendue as that of said LED optical source, said non-imaging optic having an entrance aperture, an exit aperture, and a non-rotationally symmetric cross-sectional shape that continuously enlarges from said entrance to said exit aperture, said at least one LED optical source being positioned at and fully across said entrance aperture so that said entrance aperture is substantially uniformly filled by said output of said LED optical source, said output of said at least one LED optical source being directed by said non-imaging optic shape to emerge from said exit aperture as a beam having substantially the same étendue as that of said at least two LED optical sources but altered in angle and dimensions to substantially match the étendue of the downstream application,
• a combiner for receiving the outputs from said beams from said at least two non-imaging optics having different spectral content and combining them for travel as a single beam whose content is a uniform mixture of the spectral content of both beams, and
• a beam homogenizer for receiving said single beam emerging from said combiner, said homogenizer being tilted to compensate for keystoning effects.

An illumination apparatus for providing an output beam that matches the étendue of a downstream application, said illumination apparatus comprising

• at least one LED optical source having a predetermined étendue and spectral output;
• at least one non-imaging optic for collecting substantially all of the light emitted by said at least one LED optical source and re-emitting it as a beam of substantially the same étendue as that of said LED optical source, said non-imaging optic having an entrance aperture, an exit aperture, and a non-rotationally symmetric cross-sectional shape that continuously enlarges from said entrance to said exit aperture, said at least one LED optical source being positioned at and fully across said entrance aperture so that said entrance aperture is substantially uniformly filled by said output of said LED optical source, said output of said at least one LED optical source being directed by said non-imaging optical-optic shape to emerge from said exit aperture as a beam having substantially the same étendue as that of said at least one LED optical source but altered in angle and dimensions to substantially match the étendue of the downstream application,
• a digital device for selectively modulating light incident thereto;
• and
• a relay lens for imaging the near field from said non-imaging optic onto said digital device to form video images, said relay lens imaging the far field of said beam from said non-imaging optic into the aperture stop of said projection lens.