US Patent 7314280 Projector apparatus

A projector apparatus includes: an optical system unit including an optical prism unit having liquid crystal panels for modulating red light, green light, and blue light and a dichroic prism, and a PS conversion device for aligning the polarization directions of the light from a light source lamp; cooling means for cooling the optical system unit; and an outer cabinet for mounting the optical system unit and the cooling means. The cooling means includes: a sirocco fan having a suction port; a first air trunk for guiding the airflow from the sirocco fan through a first duct to the optical prism unit so as to cool the optical prism unit; and a second air trunk for guiding the airflow from the sirocco fan and the first duct through a second duct to the PS conversion device so as to cool the PS conversion device, the second air trunk being partitioned from the first air trunk by a partition wall; and a warm airflow having been warmed by being served to cooling from the first air trunk and the second air trunk is guided into the inside of the outer cabinet to be cooled to normal temperature, before being recirculated through the suction port to the sirocco fan.