Patent ID: 8178831

Claim:
An image display apparatus including a plurality of projection display apparatuses each for projecting an image from a projection unit onto a screen, the plurality of projection display apparatuses being arranged in a plurality of rows and in a plurality of columns to form a large screen, each of said projection display apparatuses comprising an enclosure for receiving said projection unit therein and for mounting said screen thereon, said enclosure including: first and second ducts for ventilation provided to the left and right of a region for receiving said projection unit therein and extending in a vertical direction, each of said first and second ducts having a top portion formed with an upper opening and a bottom portion formed with a lower opening; first shut-off plates capable of independently opening and closing the lower openings of said first and second ducts; and second shut-off plates capable of independently opening and closing the upper openings of said first and second ducts, said first and second ducts including first and second openings provided in wall surfaces of said first and second ducts in corresponding relation to the positions of openings of said projection unit so that an air flow path is formed between said first and second ducts through said projection unit, wherein an air flow path throughout said projection display apparatuses arranged in a vertical direction is formed by combining the opening and closing of said lower openings and said upper openings of said first and second ducts by means of said first and second shut-off plates.