| 摘要 |
PURPOSE: To improve the utilizing efficiency of outside light, thereby make it easy to see any indication, and also enhance brightness concerned by disposing a hologram at the outside of a polarizing plate at the opposite side of an observer. CONSTITUTION: The device is composed of a liquid crystal cell 10, and of paired polarizing plates 13 and 14 which are disposed while the liquid crystal cell 10 is being sandwitched. A hologram 22 is stuck to the polarizing plate 14 at the back face side, and a reflection plate 21 is disposed at the rear face side of the aforesaid polarizing plate. Light from the outside is injected into the liquid crystal cell 10 while being linearly polarized by the polarizing plate 13 at the surface side. In the section of the liquid crystal cell 10 where voltage is applied between the electrodes 15 and 16 of both substrates 11 and 12, light linearly polarized passes therethrough as is with no rotation made in the polarizing direction because liquid crystal molecules are theoretically erected to the direction normal to each substrate, and light is absorbed because the transmission axis of the polarizing plate 14 at the rear side is shifted by 90 deg.. By this constitution, the section held between the electrodes 15 and 16 to which voltage is applied looks black. The aforesaid black color is diffracted by the hologram 22, reflected by the reflection plate 21, passes through the two polarizing plates 13 and 14 and the liquid crystal cell 10 again, and its transmission light is thereby reduced. |
