| 摘要 |
PROBLEM TO BE SOLVED: To efficiently cut the zero-order light in a hologram cut filter and to prevent problems of decrease in contrast or decrease in chromaticity in a display device, by using long-chain dye molecules which has absorptivity to the component of light parallel to the axis of the molecule but have no absorptivity to the component of light in the normal direction of the molecular axis. SOLUTION: The long-chain dye molecules in the dichroic dye show different absorptivities of light depending on the direction of the molecular axis. The molecules have almost no absorptivity to the component of light in the normal direction of the molecular axis and transmit the light, but the molecules have absorptivity to the component of light in the parallel direction to the molecular axis and does not transmit light. Therefore, in a hologram color filter 5 with <=40 deg. incident angle of back light 3, for example, the diffracted light 15 with wavelength dispersion by the optical film 19 can be condensed into a liquid crystal display device without cutting, while the zero-order transmitted light 14 can be completely cut. |
