| 摘要 |
PROBLEM TO BE SOLVED: To provide a video display device improving color purity of RGB and widening a color reproducing region even when using a display element having a color filter. SOLUTION: The color filter of the display element is composed of three filters which respectively transmit light beams of RGB. When wavelength widths of diffraction efficiency half-value of RGB in a hologram optical element are respectivelyΔλ1(Δλ1<SB>R</SB>,Δλ1<SB>G</SB>,Δλ1<SB>B</SB>) and wavelength widths of transmissivity half-value of RGB in a color filter are respectivelyΔλ2(Δλ2<SB>R</SB>,Δλ2<SB>G</SB>,Δλ2<SB>B</SB>), the following relation holds for respective colors;Δλ1<Δλ2, that isΔλ1<SB>R</SB><Δλ2<SB>R</SB>,Δλ1<SB>G</SB><Δλ2<SB>G</SB>,Δλ1<SB>B</SB><Δλ2<SB>B</SB>. Thereby, with respect to respective colors of RGB, only light beams whose wavelengths are narrowed among light beams transmitted by the color filter of the display element are diffracted by the hologram optical element and are guided to pupils of an observer. COPYRIGHT: (C)2007,JPO&INPIT
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