Projection display systems utilizing color scrolling and light emitting diodes

A projection display system, comprising:

• a light-recycling illumination system, further comprising:
• a light source for generating light, wherein said light source is at least one light-emitting diode having a reflecting layer, wherein the total light-emitting area of said light source is area AS and wherein said light source has a maximum intrinsic source luminance;
• a light-recycling envelope, wherein said light-recycling envelope encloses said light source and wherein said light-recycling envelope reflects and recycles a portion of said light generated by said light source back to said reflecting layer;
• a light output aperture, wherein said light output aperture is located in a surface of said light-recycling envelope, wherein the area of said light output aperture is area AO, wherein said area AO is less than said area AS, wherein said light source and said light-recycling envelope direct at least a fraction of said light out of said light-recycling envelope through said light output aperture and wherein said fraction of said light exits said light output aperture as uncollimated light having a maximum exiting luminance;
• a light-collimating means, wherein said light-collimating means has an input surface that is adjacent to said light output aperture that accepts said uncollimated light, wherein said light-collimating means partially collimates said uncollimated light and wherein said light-collimating means has an output surface through which the partially collimated light is transmitted;
• a color scrolling means to scan said partially collimated light, wherein said color scrolling means is located in the light optical path of said partially collimated light exiting said light-collimating means;
• and
• an imaging light modulator, wherein said imaging light modulator is located in said light optical path in a position following said color scrolling means, and wherein said imaging light modulator spatially modulates the scanned said partially collimated light to form an image that is projected onto a viewing screen.