Patent attributes
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.
