LIGHT SOURCE UNIT, PROJECTION DISPLAY DEVICE, LIGHTING FIXTURE, AND METHOD FOR EMITTING LIGHT

摘要

A light source unit having high utilization efficiency of light is provided. This light source unit (110) comprises a light-emitting means (1), a wavelength conversion means (2), and a first-wavelength selection means (4). The light-emitting means (1) has a light-emitting surface (41) for emitting first-wavelength-band light (30) and for reflecting and emitting incident light. The wavelength conversion means (2) has a light-receiving and -emitting surface (42) for emitting second-wavelength-band light (31) to the same side as the side on which the first-wavelength-band light (30) is incident when first-wavelength-band light (30) is incident, and for reflecting and emitting the second-wavelength-band light (31) that is incident again. The first-wavelength selection means (4) has a first reflection surface (44a) for reflecting the first-wavelength-band light (30) and transmitting the second-wavelength band light (31). The light-emitting means (1) and the first-wavelength selection means (4) are disposed so that the first-wavelength-band light (30) emitted from the light-emitting surface (41) of the light-emitting means (1), the first-wavelength-band light (30) reflected by the first reflection surface (44a) of the first-wavelength selection means (4), and the first-wavelength-band light (30) incident on and reflected by the light-emitting surface (41) of the light-emitting means (1) are incident on the light-receiving and -emitting surface (42) of the wavelength conversion means (2).