Patent ID: 8919976

Claim:
A light source device, comprising: a solid-state light source configured to emit blue light as excitation light; a wavelength conversion section configured to be excited by the excitation light from the solid-state light source so as to emit fluorescent light longer in wavelength than the excitation light emitted from the solid-state light source and to include a light extraction surface through which light exits; and a wavelength selective structure located between the wavelength conversion section and the solid-state light source and configured to transmit the excitation light from the solid-state light source and to reflect the fluorescent light from the wavelength conversion section, the wavelength selective structure having a size within a range which is less than a size of the wavelength conversion section and which is greater than a size of a spot of the excitation light irradiated with the solid-state light source by an amount of a handling tolerance provided for adjusting a position of the spot of the excitation light irradiated with the solid-state light source, wherein a region which is located between the wavelength conversion section and the solid-state light source and other than a region where the wavelength selective structure is located includes a second wavelength selective structure located on the same plane as the wavelength selective structure and configured to reflect the excitation light from the solid-state light source and to transmit the fluorescent light from the wavelength conversion section, and part of the excitation light incident upon the wavelength conversion section is reflected by the light extraction surface of the wavelength conversion section toward the second wavelength selective structure so as to be selectively reflected by the second wavelength selective structure.