Patent ID: 9733500
Date: 2017-08-15
CPC Classifications: G02F

Claim:
1. An illumination unit comprising: a first transparent substrate and a second transparent substrate that are arranged to be separated from each other and to face each other; a light source applying light to an end face of the first transparent substrate; and a light modulation layer provided in a gap between the first transparent substrate and the second transparent substrate and exhibiting scattering characteristics or transparency with respect to the light from the light source depending on magnitude of an electric field, an optical axis of the light modulation layer varies in a thickness direction, the light modulation layer including a first region including a liquid crystal material and that has optical anisotropy and relatively-high responsiveness to the electric field and a second region including a polymer material and that has optical anisotropy and relatively-low responsiveness to the electric field, and the light modulation layer satisfying a following expression when the light modulation layer exhibits the scattering characteristics, where A is magnitude of first scattering with respect to the light propagating in an X-axis direction that is perpendicular to the end face, upon no voltage application to the light modulation layer, B is magnitude of second scattering with respect to the light propagating in a Y a-axis direction that is parallel to the end face and is parallel to a surface of the first transparent substrate, upon no voltage application to the light modulation layer, a Z-axis direction being perpendicular to the X-axis and Y-axis, A B