Lcd projecting system having dichroic mirrors for polarization conversion

A system (200, 300, 400, 500, 600) for projecting an image on a display comprising:

• a first dichroic means(212) receiving a first (204), a second (206) and a third (208) primary coloured light beam and adapted to transmit the first (204) and to reflect the second (206) and third (208) primary coloured light beams,
• a second dichroic means (220) receiving said second (206) and third (208) primary coloured light beam and adapted to reflect said second (206) primary coloured light and to transmit said third (208) primary coloured light beam, characterized in further comprising:
• a first polarizing means (216, 304) receiving said first primary coloured light beam (204), a second polarizing means (222, 404) receiving said second primary coloured light beam (206), and a third polarizing means (226, 602) receiving said third primary coloured light beam (208), which first, second and third polarizing means (216, 304, 222, 404, 226, 602) being adapted to transmit light polarized in a desired direction, and further comprising a reflective rotating means (210, 202) receiving reflected first, second and third primary coloured light beams (204, 206, 208) polarized in an undesired direction from at least one of said first, second and third polarizing means (216, 304, 222, 404, 226, 602) and adapted to convert said light polarized in said undesired direction to converted light polarized in said desired direction and reflect said converted light back to said first, second and third polarizing means (216, 304, 222, 404, 226, 602).