| 摘要 |
Provided is an illumination device, which selectively radiates right circularly polarized light or left circularly polarized light, wherein a reflective polarizing plate (1), a light source, and a reflective polarizing plate (2) are contained in the given order, a waveplate is further contained, the reflective polarizing plate (1), light source, and reflective polarizing plate (2) are disposed in a manner so that polarized light reflecting off of the reflective polarizing plate (1) passes through the reflective polarizing plate (2), and the polarized light reflecting off of the reflective polarizing plate (2) passes through the reflective polarizing plate (1), and the phase difference and disposition of the waveplate are adjusted in a manner so that one type of circularly polarized light is emitted in both the direction of the reflective polarizing plate (1) and the direction of the reflective polarizing plate (2) with the light source as a baseline. The illumination device radiates, in an energy efficient manner, left circularly polarized light or right circularly polarized light. |
