Optical system unit for projecting images and including light smoothing unit formed into substantially truncated quadrangular pyramid, and projector including the same optical system

Abstract

An optical system unit having a light smoothing unit for emitting a light beam which is substantially parallel to an optical axis and a projector including the optical system unit are provided. The optical system unit includes a light source-side optical system, a display device for forming an image by reflected light and a projection-side optical system, whereby a light beam emitted from the light source unit is shone on to the display device via the light source-side optical system, an image is formed by the display device, and the image so formed is projected on to a screen via the projection-side optical system. The light smoothing unit of the light source-side optical system is such that at least one side of sides other than an incident side and an emitting side is disposed obliquely relative to a side which the at least one side confronts so that an area of the emitting side becomes larger than an area of the incident side.