| 摘要 |
PROBLEM TO BE SOLVED: To provide a light source device emitting a reduced light flux in an approximately same direction as the optical axis of the incident light flux, an illumination device, and a projector.SOLUTION: A light source device includes a light source unit emitting a light flux, and a reducing optical system including a plurality of optical elements and reducing the cross section of the light flux. Each of the optical elements includes first and second surfaces and first and second reflection surfaces, and shifts the optical path of the corresponding light beam in the light flux in a first direction by reflecting the light beam in order on the first reflection surface and the second reflection surface through the first surface and the emitting the light beam from the second surface. The light flux is incident into the reducing optical system along a second direction. First and second optical elements are provided in order in the second direction. The first reflection surface of the second optical element is provided on a side opposite to the first direction relative to the first reflection surface of the first optical element, or the second reflection surface of the second optical element is provided on a side opposite to the first direction relative to the second reflection surface of the first optical element.SELECTED DRAWING: Figure 3 |
