Patent ID: 6783242
Filing Date: 2004-08-31
Classification: G02B,H04N

Abstract:
A projection apparatus comprising:a polarizing converter which converts a light beam from a light source to a polarized beam; a color separator which separates the polarized beam into first, second, and third color beams based on wavelength; a first, a second and a third optical path modifier each of which modifies an optical path associated with a corresponding one of the color beams; a first, a second and a third polarized light separator, each of which receives a corresponding one of the first, second, and third color beam from the optical path modifiers; a first, a second and a third reflective image display element, each of which receives a corresponding one of the first, second, and third color beams from the corresponding polarized light separator and provides a reflected beam to the corresponding polarized light separator; a color combiner which combines the reflected beams from the reflective image display elements of the polarized light separator; a projection lens which projects a color image from the color combiner; and wherein the color combiner comprises prisms formed from at least two types of base materials having different wavelengths at which an absolute value of a photoelastic constant is a minimum, Sc and Si satisfy the relationship Sc