| 摘要 |
PURPOSE:To improve the utilization efficiency of a light source for irradiating a liquid crystal display board, etc. CONSTITUTION:A light beam 3 from the light source 1 and a light beam 3 reflected by a reflection mirror 2 are condensed by a condenser lens 4, and transmitted through a 1/4 wavelength plate 5. Then, the light beam 7 which is made incident on a polarizing device 6 and polarized in a vertical direction, for example, is transmitted and the light beam 8 which is polarized in a horizontal direction is reflected. The reflected light beam 8 is made incident on the 1/4 wavelength plate and becomes a circularly polarized light beam 9. The light beam 9 is reflected by the reflection mirror and becomes a circularly polarized light beam 10 whose rotating direction is inverted, and it is made incident on the 1/4 wavelength plate and becomes a light beam 11 polarized in the vertical direction, then it is transmitted through the polarizing device and outputted together with the light beam 7. |
