Patent ID: 8023176

Claim:
A display method for an optical device comprising: layering the mobile particles at least on the surface of the periodic structure, and the optical device comprises a pair of substrates, and between the substrates are arranged a light transmissive dispersion medium, a periodic structure arranged in the dispersion medium and having a porous structure inside communicated with the outside, and mobile particles contained in the dispersion medium so as to be movable and having a volume average primary particle diameter of 1 nm or larger and 80 nm or smaller in a dispersion state in the dispersion medium, a volume average particle diameter of coagulated particles of 100 nm or larger in optical coagulation state by applying a voltage, and having a refractive index different from that of the dispersion medium by 0.1 or more, the mobile particles being present in the dispersion medium irrespective of said voltage.