Patent ID: 7544002

Claim:
An optical device, comprising: a sealed container that has edge walls and a side wall, the edge walls facing each other in a thickness direction of the container, the side wall connecting both of the edge walls; a first liquid that has polarity or electrical conductivity, the first liquid being sealed within the container; a second liquid that is sealed within the container and does not mix with the first liquid; and voltage applying means for applying a voltage across the first liquid; wherein: the first liquid and the second liquid have equal specific gravity; transmissivity of the first liquid is lower than the transmissivity of the second liquid; an interface between the first liquid and the second liquid changes shape in response to a voltage applied by the voltage applying means; a light transmission path that passes through the edge walls and extends in a direction of the thickness of the container is formed; a hydrophilic film that is formed on a portion inside the side wall corresponding to the first liquid, wettability of the hydrophilic film with respect to the first liquid being higher than wettability of the hydrophilic film with respect to the second liquid; a water-repellant film that is formed on a portion inside the side wall corresponding to the second liquid, wettability of the water-repellant film with respect to the second liquid being higher than wettability of the water-repellant film with respect to the first liquid; the voltage applying means includes a first electrode provided on an entire circumference of the inside of the side wall and a second electrode provided along an outer circumference of the inside of the edge wall on a side on which the first liquid is located; the hydrophilic film and the water-repellant film are provided so as to cover a surface of the first electrode; another hydrophilic film is formed on an inner portion of the second electrode and on the inside of the edge wall on a side on which the first liquid is located; and wettability of the another hydrophilic film with respect to the first liquid is higher than wettability of the another hydrophilic film with respect to the second liquid.