Patent ID: 6905213

Claim:
A projection-type image display apparatus comprising: color separator which separates a light beam from a light source into first, second, and third color beams based on wavelength ranges; image display elements which receives said first, second, and third color beams from said color separator; color combiner which combines color beams from said image display elements; projection lens which magnifies and projects a color image combined by said combiner; a screen installed at a predetermined position and onto which projection image light from said projecting means is projected; and at least two light-detecting elements which detect light intensity at the outside of said screen, wherein said image display elements include a surplus display region that can be activated being arranged outside an effective display region, wherein said projection lens magnifies and projects images, including said surplus display region, up to an outer screen, wherein an active region for said image display elements is controlled by detection results from said light-detecting elements associated with said first, said second, and said third projection image lights.