Light Source Device, and Two-Dimensional Image Display Device

摘要

There is provided a light source device which can miniaturize a two-dimensional image display device as small as possible. The light source device is provided with three coherent light sources ( 11 a), ( 11 b), and ( 11 c) corresponding to red, blue, and green; prisms ( 12 a) and ( 12 c) for reflecting lights emitted from the coherent light sources ( 11 a) and ( 11 c); and a diffraction part ( 20 ) comprising a single volume hologram on which plural gratings are multiply-formed, which gratings diffract the light emitted from the coherent light source ( 11 b), and the lights that are emitted from the coherent light sources ( 11 a) and ( 11 c) and reflected by the prisms ( 12 a) and ( 12 b) so that these lights propagate in the same optical path.