Abstract: Provided is an optical unit that includes: light source (1a); light source (1b) located to face light source (1a); color wheel (2) located between light sources (1a and 1b); prism unit (3a) that totally reflects light emitted from light source (1a) and that is transmitted through color wheel (2), and transmits light emitted from light source (1b) to enter color wheel (2); and prism unit (3b) that totally reflects the light emitted from light source (1b) and that is transmitted through color wheel (2), and transmits the light emitted from light source (1a) to enter color wheel (2).

Abstract: Provided is an optical unit that includes: light source (1a); light source (1b) located to face light source (1a); color wheel (2) located between light sources (1a and 1b); prism unit (3a) that totally reflects light emitted from light source (1a) and that is transmitted through color wheel (2), and transmits light emitted from light source (1b) to enter color wheel (2); and prism unit (3b) that totally reflects the light emitted from light source (1b) and that is transmitted through color wheel (2), and transmits the light emitted from light source (1a) to enter color wheel (2).

Abstract: A projection optical system which improves the illumination efficiency includes a light source, an optical waveguide into which light from the light source enters and from which the light exits as reflected light, a diffuser diffusing light that has exited from the optical waveguide, a prism sheet into which light diffused by the diffuser enters and in which prisms are arranged on one plane, and a rod integrator into which light transmitted through the prism sheet enters.

Abstract: In a projection display device that is provided with a relay lens for converting flux that is emitted from a light source to a parallel flux for illuminating an image display element (DMD), and a total internal reflection prism for both directing flux that is emitted from the relay lens to the DMD and directing flux that is reflected by the DMD toward a projection lens, the relay lens is unified with the prism as a lens-integral prism by bonding the relay lens to the total internal reflection surface of the prism.

Abstract: In a projection display device that is provided with a relay lens for converting flux that is emitted from a light source to a parallel flux for illuminating an image display element (DMD), and a total internal reflection prism for both directing flux that is emitted from the relay lens to the DMD and directing flux that is reflected by the DMD toward a projection lens, the relay lens is unified with the prism as a lens-integral prism by bonding the relay lens to the total internal reflection surface of the prism.

Abstract: In a projection display device that is provided with a relay lens for converting flux that is emitted from a light source to a parallel flux for illuminating an image display element (DMD), and a total internal reflection prism for both directing flux that is emitted from the relay lens to the DMD and directing flux that is reflected by the DMD toward a projection lens, the relay lens is unified with the prism as a lens-integral prism by bonding the relay lens to the total internal reflection surface of the prism.

Abstract: A projection display apparatus has: a TIR prism having a first prism surface, a second prism surface, and a third prism surface; a projection lens which is disposed opposite to the first prism surface; and an image display device which is disposed opposite to the second prism surface. The image display device reflects incident light in a first direction or in a second direction in accordance with an image signal. The first, second, and third prism surfaces are formed so as to define a modulated light path, wherein the light is reflected in the first direction, then is incident on the second prism surface, then is totally reflected internally on the third prism surface, then exits from the first prism surface, and then is incident on the projection lens along the modulated light path.

Abstract: In a projection display device that is provided with a relay lens for converting flux that is emitted from a light source to a parallel flux for illuminating an image display element (DMD), and a total internal reflection prism for both directing flux that is emitted from the relay lens to the DMD and directing flux that is reflected by the DMD toward a projection lens, the relay lens is unified with the prism as a lens-integral prism by bonding the relay lens to the total internal reflection surface of the prism.