Patent ID: 7408691
Filing Date: 2008-08-05
Classification: G02B,G03B

Abstract:
1. A variable aperture, comprising: a chamber including a first transparent portion and a second transparent portion on an opposite side of the chamber to the first transparent portion; a transparent and electrically conductive aqueous solution contained in the chamber; an opaque and electrically non-conductive oily solution contained in the chamber, the oily solution and the aqueous solution cooperatively forming a contact interface therebetween; a transparent insulative and hydrophobic layer arranged between the oily solution and the second transparent portion of the chamber; a first electrode brought into electrically contact with the aqueous solution; and a second electrode assembly arranged adjacent to the second transparent portion of the chamber, the second electrode assembly including a transparent circular electrode and a concentric transparent annular electrode surrounding the transparent circular electrode therein, the circular electrode being insulated from the annular electrode; a voltage supply having a first output terminal electrically connected to the first electrode, and a second output terminal for being selectively connected to at least one of the transparent circular electrode and the transparent annular electrode of the second electrode assembly.