Patent ID: 6454413
Filing Date: 2002-09-24
Classification: G02B,H04N

Abstract:
An image projection system comprisingan illumination system comprising a radiation source for supplying a first and a second light beam in a first and a second color, respectively, a modulation system comprising two image panels for modulating the first and second light beams with image information, polarization-sensitive filter means situated between the radiation source and the modulation system for supplying a first sub light beam contributing to the first light beam having a first direction of polarization and for supplying a second sub light beam contributing to the second light beam having a second direction of polarization, the second direction being perpendicular to the first direction, polarization conversion means situated between the radiation source and the polarization-sensitive filter means, color-filtering means situated between the polarization-sensitive filter means and the modulation system for supplying, in combination with the polarization-sensitive filter means and the polarization conversion means, the first light beam having a first color and a first direction of polarization and the second light beam having a second color and a second direction of polarization, characterized in that the color filter means are further arranged to transmit a first light sub-beam of the first color contributing to the first light beam, a second light sub-beam of the second color contributing to the second light beam, to reflect a third sub-light beam of the second color and the first direction of polarization and a fourth sub-light beam of the second color and the second direction of polarization, respectively, the polarization conversion means are situated between the radiation source and the polarization-sensitive filter means for converting the second direction of polarization of the reflected fourth light sub-beam into the first direction of polarization and the first direction of polarization of the reflected third light sub-beam into the second direction of polarization and the polarization-sensitive filter means are arranged to combine the first light sub-beam and the fourth light sub-beam in the first light beam and the second and third light sub-beams in the second light beam.