| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a polarization conversion element having a low production cost. <P>SOLUTION: The polarization conversion element 5 comprises a birefringent plate 6 and is provided with a 1/2 wavelength plate 7 on a prescribed position of the birefringent plate 6. When randomly polarized light L1 is made incident to the polarization conversion element 5, a component of linear polarization in the direction orthogonal to the light axis of the birefringent plate 6 becomes a normal light ray, advances on an optical path of incident light L1 as it is, becomes linearly polarized light L2 and is emitted from a second path, in a birefringent plate 6. Also, a component of linear polarization in the direction parallel to the light axis of the birefringent plate 6 becomes an abnormal light ray, refracts in the birefringent plate 6, becomes a linearly polarized light ray L3 and is separated. Further on an emission surface of the linearly polarized light L3 becoming an abnormal light ray, the 1/2 wavelength plate 7 is disposed; a polarization surface of linearly polarized light is rotated by 90° and the abnormal light ray is converted into a linearly polarized light L3' in the polarization direction equal to the linearly polarized light L2 of a normal light ray and is emitted from the first path. <P>COPYRIGHT: (C)2007,JPO&INPIT |
