Patent ID: 7990605

Claim:
An illumination device comprising: a light guide plate; a light source disposed on a side face of the light guide plate; and a light modulator being disposed on a surface or in an inside of the light guide plate, and being adhered to the light guide plate, wherein the light modulator has a pair of transparent substrates separately disposed in an opposed manner to each other, a pair of electrodes provided on respective surfaces of the pair of transparent substrates, and a light modulator layer provided in a gap between the pair of transparent substrates, the light modulator layer includes a first region being changed between a transparent state and a scatterable state depending on an intensity of an electric field, and a second region being more transparent than the first region in a scatterable state at an electric field having a certain intensity, the electric field being applied when the first region is changed between the transparent state and the scatterable state, and an occupancy rate of the first region in the light modulator layer is increased with increase in distance from the light source.