Digital Projection System

An apparatus comprising:

• first and second light modulation assemblies and a beam splitting assembly,
• said first and second light modulation assemblies each comprising:
• an optical element, a pre-polarization filter, an image modulator, and an analyzer polarization filter,
• said optical element having an input port for receiving a light beam, said optical element directing said light beam onto said pre-polarization filter that removes light having a linear polarization in a first direction, said light leaving said pre-polarization filter illuminating said image modulator, said light leaving said image modulator being filtered by said analyzer polarization filter to remove light having a linear polarization with a predetermined direction relative to said first direction, said light leaving said analyzer polarization filter exiting said optical element through an output port;
• and
• said beam splitting assembly comprising an optical element having an input port for receiving an input light beam and an output port for transmitting a spatially modulated output light beam, said beam splitting assembly generating a first light beam having light in a first optical band and a second light beam having light in a second optical band from said input light beam and directing said first light beam into said input port of said first light modulation assembly and said second light beam into said input port of said second light modulation assembly,
• wherein said first light beam follows a path having a first optical path length from said input port of said beam splitting assembly to said first image modulator and said second light beam follows a path having a second optical path length from said input port of said beam splitting assembly to said second image modulator, said first optical path length being substantially equal to said second optical path length.

A method for spatially modulating an input light beam at an apparatus input port to form an output light beam at an apparatus output port, said method comprising:

• splitting said input light beam into a first component light beam having light in a first band of the optical spectrum and a second component light beam having light in a second band of the optical spectrum;
• directing said first component light beam to a first light modulation assembly and said second light beam to a second light modulation assembly, said first and second light modulation assembly spatially modulating said first and second component light beams to provide first and second spatially modulated output light beams;
• combining said first and second spatially modulated output light beams to form said output light beam,
• wherein said first and second light modulation assemblies each comprise:
• an optical element, a pre-polarization filter, an image modulator, and an analyzer polarization filter,
• wherein light entering said apparatus input port that is directed to said image modulator in said first light modulation assembly traverses an optical path having substantially the same optical path length as light entering said apparatus input that is directed to said image modulator in said second light modulation assembly.