Patent ID: 9575402
Date: 2017-02-21
CPC Classifications: G02B,G03B,H04N

Claim:
1. An illumination optical system configured to illuminate an image display device using a light flux from a light source, the illumination optical system comprising: a polarization splitter having a first polarization splitting surface configured to split a polarization component of the light flux; a first compression system configured to compress the light flux on each of a first section that contains a normal of the first polarization splitting surface and an optical axis of the illumination optical system, and a second section that contains the optical axis and is orthogonal to the first section; a polarization converter configured to convert non-polarized light into linearly polarized light and that includes a second polarization splitting surface, and is arranged so that a section that contains a normal of the second polarization splitting surface and the optical axis becomes the second section; and a second compression system configured to compress the light flux in the first section and includes: wherein the following conditions are satisfied: where α is a compression ratio applied by the second compression system in the first section and β is a compression ratio applied by the first compression system in the first and second sections.