Patent ID: 7645977

Claim:
An insulated glazing unit having controllable radiation transmittance, said insulated glazing unit comprising: a spacer defining a framed area capable of allowing radiation transmission therethrough; a first glazing pane attached to said spacer; a second glazing pane attached to said spacer, said glazing panes arranged such that an inner surface of said first glazing pane and an inner surface of said second glazing pane face each other and are spaced apart from each other; a conductive layer disposed on said inner surface of said first glazing pane; a dielectric layer disposed on said conductive layer; a shutter disposed between said first glazing pane and said second glazing pane, said shutter including a resilient layer and a further conductive layer, said shutter having a width extending substantially across a width of the framed area within at least a portion of said further conductive layer in contact with said dielectric layer, said shutter adapted to extend substantially along a length of the framed area from a contracted configuration having a first surface area substantially permitting radiation transmission through said framed area to an expanded configuration having a second surface area substantially controlling radiation transmission through said framed area; whereby, when a voltage is applied between said conductive layer and said further conductive layer a potential difference between said conductive layer and said further conductive layer causes said shutter to expand from said contracted configuration to said expanded configuration.