| 摘要 |
A projection type image display device using, in a projection optical system thereof, a flat mirror, which is easy to design and manufacture, as a projection mirror is provided. The projection optical system is a diagonal projection optical system and includes plural lenses. Among the plural lenses, the one disposed closest to the flat mirror has an effective area, along the vertical direction of an image, through which a light beam passes and which is off the optical axis, among optical axes of the plural lenses, shared by the most lenses so as not to allow light reflected from the projection mirror to return to the projector body. A polarization converter using, for example, a quarter wavelength plate is provided at an output surface of a crossed prism to decrease reflectance differences between differently colored light and to thereby prevent the occurrence of color unevenness. |
