BACKLIGHT DEVICE AND IMAGE DISPLAY APPARATUS

摘要

Disclosed is a backlight device which comprises a substrate (2), a liquid crystal layer (4), and a scattering layer (5). Two comb-shaped electrodes (3a, 3b) are formed on a side of the substrate (2) adjacent to the liquid crystal layer (4). A plurality of comb tooth portions (33a) included in the comb-shaped electrode (3a) are engaged with a plurality of comb tooth portions (33b) included in the other comb-shaped electrode (3b). With this structure, electric fields having two or more directions that differ from each other while the directions are parallel to the surface of the substrate (2) can be generated by applying voltage to the electrodes. Since the effective refractive index is partially increased for both p-polarized light and s-polarized light due to the electric fields, emission of both the p-polarized light and the s-polarized light can be controlled.