| 摘要 |
PROBLEM TO BE SOLVED: To significantly decrease the reflectance during dark display or black display and to significantly improve the contrast. SOLUTION: Antireflection films 51, 53 and 52, 54 each consisting of two layers are formed between a substrate 11 and a transparent electrode 21 and between a substrate 12 and a transparent electrode 22, respectively. The optical film thickness of each of the transparent electrodes 21, 22 and antireflection films 51, 52 is controlled to λ/4, while the optical film thickness of each of the antireflection films 53, 54 is controlled to λ/2, wherein λ is the wavelength of the light to prevent reflection. For example, λ is aimed at 555 nm, which gives the highest luminosity. When a cholesteric liquid crystal 30 has focal conic alignment, the forward scattering in the cholesteric liquid crystal 30 of the incident light reflected by the transparent electrode 22 can be decreased around λ and the reflectance during dark display is decreased around λ, which improves the contrast. Antireflection films may be formed on both sides of each of the transparent electrodes 21, 22 to interpose the electrodes 21, 22. Or, antireflection films are not formed separately from the transparent electrodes 21, 22 but the optical film thickness of the transparent electrodes 21, 22 may be controlled to λ/2. |
