| 摘要 |
<p>The application relates to a_bistable twisted nematic (BTN) liquid crystal display device comprising a liquid crystal layer (150) situated between first and second polarizers (100, 200), said layer (150) in the absence of an applied electric field having two stable, uniformly twisted textures, and at least one compensation layer (110, 190) positioned between said first and second polarizers (100, 200), said compensation layer (110, 190) being composed of at least one birefringent film, said birefringent film having an optical anisotropy defined by three characteristic refractive indices nx, ny, nz, with nx ‰¥ ny and nz being perpendicular to the plane of the cell substrates (120, 180) with biaxiality parameter Nz equal to (nx-nz)/(nx-ny), characterized in that Nz lies between - ˆž and 1 in order to compensate the birefringence of the bistable texture corresponding to the dark optical state in the case of oblique observation and thus improve the range of viewing angles to achieve a high contrast ratio and minimal color shift.</p> |
