Patent ID: 8757814

Claim:
A light source unit comprising: an excitation light source for shining light of a predetermined wavelength band; an optical wheel having a plurality of segment areas, the plurality of segment areas including at least two luminescent material layers having different characteristics and a transmission portion which transmits light emitted from the excitation light source, wherein the plurality of segment areas are provided side by side in a circumferential direction; a rotation driving unit for driving to rotate the optical wheel; a light emitting element provided out of an optical path of the optical wheel; a light guiding optical system for guiding a light beam emitted from the optical wheel and a light beam emitted from the light emitting element to converge to a same optical path; and a control unit for turning on the excitation light source when any one of the transmission portion and the luminescent material layers is positioned on an optical axis of excitation light and for turning on the light emitting element for a period of time during which the excitation light source does not shine the excitation light wherein in the optical wheel, at least areas of luminescent light emitting areas where the luminescent material layers are provided are formed as reflecting planes.