Patent ID: 8330907

Claim:
A liquid crystal display element comprising: a transparent substrate having formed on a surface thereof a transparent electrode and a first alignment layer covering the transparent electrode; a drive circuit board disposed in opposition to the transparent substrate and having formed on a surface thereof facing the transparent electrode a plurality of drive circuits and a plurality of reflection pixel electrodes, corresponding to pixels, respectively, a protective layer covering the plurality of reflection pixel electrodes and a second alignment layer covering the protective layer; and a liquid crystal layer interposed between the first alignment layer on the transparent substrate and the second alignment layer on the drive circuit board, wherein, the protective layer is a stack of at least first and second dielectric layers different in refractive index from each other, the first and second dielectric layers are relatively layered in that order on the plurality of reflection pixel electrodes, the liquid crystal display element further comprises a mirror structure in which the refractive index of the second dielectric layer is greater than that of the first dielectric layer and also that of the second alignment layer so that the protective layer is effective to reflect light and the second alignment layer is effective as an optical layer, the second alignment layer and the first dielectric layer having the same composition, the first dielectric layer, the second dielectric layer and the second alignment layer being alternately stacked on the plurality of reflection pixel electrodes so as to form the mirror structure, a ratio of the thickness of each of the stacked dielectric layers compensates for the wavelength dependence of the reflectance of the reflection pixel electrodes, wherein for a predetermined total thickness of the stacked dielectric layers said ratio of the thickness of each of the stacked dielectric layers is selected from the group consisting of: a one-to-one, a one-to-two, and a two-to-one ratio for the first and second dielectric layers, respectively, such that the reflectance is approximately constant over a waveband of plural wavelengths, and the liquid crystal layer has vertically-aligned liquid crystal molecules pretilted by both the first and second alignment layers.