Patent ID: 8882321

Claim:
A light source device including: an excitation light source that emits excitation light; a light guide member including a light guide incidence end face through which the excitation light emitted from the excitation light source incidents and a light guide emission end face from which the excitation light is emitted, and guiding the excitation light from the light guide incidence end face to the light guide emission end face; and a wavelength conversion unit that converts the excitation light emitted from the light guide emission end face into wavelength converted light having a desired wavelength, wherein the wavelength conversion unit includes: an optical element disposed on an optical axis as a center axis of the excitation light emitted from the light guide emission end face and with which the excitation light emitted from the light guide emission end face is irradiated to scatter the excitation light; a wavelength conversion member disposed on an optical path of the excitation light scattered by the optical element and with which the excitation light is irradiated when the excitation light is scattered to convert the irradiated excitation light into the wavelength converted light; and an emission opening portion that emits the wavelength converted light converted by the wavelength conversion member to an outside of the wavelength conversion unit, wherein the wavelength conversion member includes an incidence end face on which the excitation light is incident when the wavelength conversion member is irradiated with the excitation light and an emission end face from which the wavelength converted light is emitted and which is the same surface as the incidence end face, wherein the wavelength conversion member is a desired distance away from the optical element, and wherein the optical element includes a scattering optical element having a scattering surface that scatters the excitation light in a random direction and the scattering surface is opposed to the light guide emission end face.