An image display apparatus of a projection-type is provided which includes an illuminator with a light source, an optical modulator illuminated by light illuminator and which makes spatial modulation of the illumination light according to a to-be-displayed image for either transmission or reflection, and a projection lens to form an image of the optical modulator. The apparatus includes also a first reflecting element to reflect, towards the light source, the unwanted light of the light beam emitted from the illuminator and which will not illuminate the optical modulator, and a second reflecting element to guide, by reflecting, the unwanted light once reflected by the first reflecting element. In the apparatus, the combination of the light source and illuminator, which can recycle the unwanted light efficiently in the projector, makes it possible to inexpensively separate and recombine polarized components of the light beam. Use of a single-plate optical modulator formed from a color filter permits to utilize the light with an improved efficiency. Also by adopting a single-plate optical modulator of a sequential color-type, it is possible to attain an improved efficiency of light utilization. Thus, the efficiency of light utilization of an optical modulator whose numerical aperture is small can be improved and the peak brightness on a dark screen can be elevated.
RELATED APPLICATION DATA
The present application claims priority to Japanese Application No. P2001-134535 filed May 1, 2001, and is a continuation of United States Application No. 10/136,671, filed May 1, 2002, now U.S. Pat. No. 6,910,772 all of which are incorporated herein by reference to the extent permitted by law.
Aspects of the invention can provide an illuminating device and the like capable of efficiently supplying polarized light in a particular oscillation direction and suitable for a projector having a liquid crystal type spatial light modulator. The device can include a light source that supplies light, a collimating optical system that collimates the light from the light source into a substantially parallel light, and a reflecting type polarizing plate that transmits polarized light in a particular oscillation direction in the light from the collimating optical system and reflects polarized light in an oscillation direction different from the particular oscillation direction. The light source can include a reflecting portion that reflects light reflected by the reflecting type polarizing plate and advancing in the direction of the light source toward the collimating optical system.
