| 摘要 |
PURPOSE:To convert incident light into projection light which has only one polarized component, to control its plane of polarization in >=2 directions, and to utilize both polarized components as projection light by splitting mutually orthogonal polarized components spatially and then passing them through a TN type liquid crystal cell. CONSTITUTION:The optical element is constituted by combining a part 2 which splits the incident light having the mutually orthogonal polarized components spatially with the TN type liquid crystal cell 3 for rotating the plane of polarization of at least one polarized component. The part 2 is a striped lens which uses media 4 and 6 differing in refractive index and a double refraction index material 5 and stripes of the upper and lower lenses are formed shifting by half pitch. The mutually orthogonal polarized components have different focuses and are so arranged that the focuses of the polarized components split by the part 2 are positioned at the liquid crystal layer 8 of the TN liquid crystal cell 3. Thus, the incident light is converted into the projection light which has only one polarized component and its plane of polarization can be controlled in >=2 directions. |
