Patent ID: 8134526
Filing Date: 2012-03-13
Classification: G02B,G02F,G03B

Abstract:
1. A light diffusion element comprising: a light diffusion layer that diffuses incident light; a pair of electrodes that sandwiches the light diffusion layer and configured to apply a voltage to the light diffusion layer; a voltage applying unit configured to apply a predetermined voltage to the pair of electrodes, wherein the light diffusion layer contains at least two types of liquid crystal molecules each having a different light scattering characteristic defined by the applied voltage, and includes a polymer layer having a light scattering characteristic independent of changes in a change of the applied voltage, liquid crystal molecules are distributed in the polymer layer, there are “n” types of liquid crystal molecules in a case that n is a natural number being two or more, for “i” as a natural number being 1 to n, a refractive index of the i-th liquid crystal molecule is equal to a refractive index of the polymer layer in a case that the voltage applying unit applies i-th voltage to the pair of electrodes, in a case that first voltage to n-th voltage are applied to the pair of electrodes, each strength of light scattering in (n minus 1) types of liquid crystal molecules excluding the i-th liquid crystal molecule when i-th voltage is applied, becomes substantially same value, and the voltage applying unit applies the first voltage to n-th voltage periodically, whereby an average light transmission rate of the light diffusion layer calculated for any predetermined period, becomes substantially constant.