| 摘要 |
PURPOSE: To provide a small-sized illumination system having high light utilization efficiency. CONSTITUTION: This illumination system has a polarized light selective hologram element 18 including at least one optically anisotropic materials composed to separate the light of a first polarization state from the light of a second polarization state and means 12, 20 for converting at least one light of the light in the first polarization state and the second polarization state to the light of the common polarization state. These converting means have polarization rotators, for example, a half-wave plate 20 or a quarter-wave plate 22 and a reflection plate 12 for reflecting light and allowing the passage of the quarter-wave plate in the case the polarized light selective hologram element 18 separates the two orthogonal components of the plane polarized light from each other. The converting means have the reflection plate 12 when the polarized light selective hologram element separates the components rotating reverse from each other of the circularly polarized light. |
