Patent ID: 7724311

Claim:
An optical projecting system comprising: a light source capable of providing composite source light; a light-splitting unit for receiving the composite source light provided by said light source, and for splitting the composite source light into a plurality of composite light beam components that travel in a first direction; a reflective color wheel disposed to receive the composite light beam components from said light-splitting unit, rotatable about a rotation axis, and including a plurality of multi-layer light-reflecting sections for further splitting each of the composite light beam components into a plurality of colored light beam components, each of said multi-layer light-reflecting sections including a plurality of light-filtering layers stacked along the rotation axis, each of said light-filtering layers of each of said multi-layer light-reflecting sections being capable of reflecting light within a predefined distinct wavelength range, and permitting transmission of light outside the predefined distinct wavelength range therethrough, wherein sequences of said light-filtering layers of an adjacent pair of said multi-layer light-reflecting sections are different from each other; a light-modulating unit disposed to receive the colored light beam components from said reflective color wheel, and operable to modulate the colored light beam components; and a projecting lens disposed to receive modulated light beam components from said light-modulating unit.