Patent ID: 6491397
Filing Date: 2002-12-10
Classification: G02B,H04N

Abstract:
An illumination optical system that emits illumination light, comprising:a light source that emits non-polarized light; a polarization conversion optical system that comprises at least one pair of a polarizing separation film and a reflection film, which are arranged to be mutually in parallel with each other and to be inclined relative to a predetermined direction, the polarization conversion optical system converting incident non-polarized light into linearly polarized light having a predetermined direction of polarization; a first optical system that comprises at least one first lens, which is arranged on an optical path between the light source and the polarizing separation film to emit a first light beam; and a second optical system that comprises a second lens, which receives an incident second light beam that is a component of the first light beam emitted from the first lens and is transmitted by the polarizing separation film, and a third lens, which receives an incident third light beam that is another component of the first light beam emitted from the first lens and is reflected by the polarizing separation film and the reflection film, wherein an optical property of at least one of the second lens and the third lens is adjusted to make a size of a first region on a predetermined area, which is irradiated with the second light beam, substantially equal to a size of a second region on the predetermined area, which is irradiated with the third light beam.