Patent ID: 6804040
Filing Date: 2004-10-12
Classification: G02B,G02F

Abstract:
A voltage controlling device for controlling voltage provided to at least one suspended particle device (SPD) which comprises:an AC terminal adapted to receive an AC voltage at a specific frequency; a voltage dividing device adapted to divide the AC voltage into a plurality of distinct voltage values within a predetermined range; a controller adapted to control the voltage dividing device to provide a selected voltage value based on voltage level information; an SPD terminal adapted to provide the selected voltage value to the SPD device; wherein the voltage dividing device further comprises: a capacitor array including a plurality of capacitors where each capacitor in the capacitor array has a predetermined capacitance; and a switch array, connecting each capacitor of the capacitor array to the SPD terminal such that each switch of the switch array connects one capacitor of the capacitor array to the SPD terminal, wherein the controller controls the switches of the switch array to connect at least one of the capacitors of the capacitor array to the SPD terminal based on the voltage level information.