Abstract: The purpose of the present disclosure is to provide a small optical integrator for increasing color mixing property and homogeneity. An optical integrator is provided with a light entrance surface and exit surface (002, 003), and side surfaces (004, 005, 006, 007) that connect the entrance surface and the exit surface, and is internally filled with a light guide material having a refractive index. The light guide material contains scattering particles for scattering light that have a refractive index different from the refractive index of the light guide material. The light that has entered via the entrance surface propagates from the entrance surface side toward the exit surface while being scattered by the scattering particles in the light guide material, wherein part of the scattered light is guided to the exit surface by propagating while being confined, by internal reflection on the side surfaces, in the light detector.

Abstract: An optical mixer efficiently homogenizes light flux emitted from a plurality of light sources emitting light having different wavelengths to provide a multi-wavelength homogeneous light source. The optical mixer has a columnar shape made of a transparent material, a length of the side surfaces is larger than an outermost diameter of a top surface or a bottom surface of the columnar shape, and a large number of scattering particles scattering light contained inside the optical mixer. The side surface of the optical mixer reflects light, and the top surface and the bottom surface thereof transmit light. Thereby, a function of mixing light incident from the top or bottom surface by the reflecting function of the side surface and the scattering function of the scattering particles is provided.

Abstract: To provide an illumination device having high efficiency, an illumination method, a video projection apparatus using the same. In order to achieve the object, there is provided an illumination device configured to include a light source and a light condensing body which condenses light from the light source to be emitted, and the light condensing body includes an incidence surface of a light source side, an emission surface emitting light, and a side surface which is present between the incidence surface and the emission surface, the side surface is a curved surface of which a distance from a light axis in a direction orthogonal to the light emitting surface of the light source at the center of the light source becomes large from the incidence surface toward the emission surface and has a plurality of curved-surface-shapes of which shapes of the curved surfaces are different from each other.

Abstract: The purpose of the present disclosure is to provide a small optical integrator for increasing color mixing property and homogeneity. An optical integrator is provided with a light entrance surface and exit surface (002, 003), and side surfaces (004, 005, 006, 007) that connect the entrance surface and the exit surface, and is internally filled with a light guide material having a refractive index. The light guide material contains scattering particles for scattering light that have a refractive index different from the refractive index of the light guide material. The light that has entered via the entrance surface propagates from the entrance surface side toward the exit surface while being scattered by the scattering particles in the light guide material, wherein part of the scattered light is guided to the exit surface by propagating while being confined, by internal reflection on the side surfaces, in the light detector.