| 摘要 |
<p>PURPOSE:To obtain the color filter using a hologram which can make back light incident on a liquid crystal display element almost at right angles. CONSTITUTION:As for the color filter which has a hologram 5' which converges light and has no wavelength dependency of diffraction efficiency and a hologram is irradiated slantingly with illumination light 3 to its normal and diffracts, spectrally separates, and converges the light by the hologram 5', a deflecting optical element such as a Fresnel lens 11 is arranged on the incidence side of the illumination light 3 of the hologram 5' and the deflecting optical element 11 deflects the illumination light 3, which is made incident on the hologram 5' almost at right angles, slantingly to the normal of the hologram 5'. A combination of a hologram consisting of uniform interference fringes and a light converging element may be used instead of the hologram 5' which converges the light.</p> |
