| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical unit for realizing high luminance by simultaneously improving the efficiency of incident light on a Digital Microcomputer Device (DMD) and the efficiency of reflected light from the DMD, and a projection type display device provided with the optical unit.SOLUTION: Provided is an optical unit of a projection type display device for projecting light-source light reflected by the DMD, in which one prism among TIR prisms is disposed in parallel to light-source light emission surfaces of the other prisms at a prescribed distance, and is configured to have a first boundary surface on which the light-source light from the other prisms is incident and a second boundary surface which is provided so as to face the DMD and emits the light-source light for illuminating the DMD and on which the reflected light from the DMD is incident, and, where ±&thetas; represents an oscillation angle of a micromirror of the DMD, n represents a refractive index of the prism, &bgr; represents an angle formed by the first boundary surface and the second boundary surface, and α represents a light-source light emission angle to the DMD on the second boundary surface, the oscillation angle &thetas;, the refractive index n, the angle &bgr;, and the angle α satisfy a prescribed relationship. |
