Patent ID: 7859741
Filing Date: 2010-12-28
Classification: G02B,G02F,G03B,H04N

Abstract:
1. Variable iris having a first transparent substrate and a second transparent substrate, which are separated by one or more ribs to form a cell confining charged opaque particles, the first transparent substrate being provided with at least a first electrode and a second electrode both being adapted to be connected to a voltage source for acting on the charged opaque particles, and at least a third electrode and a fourth electrode adapted to be connected to the voltage source for acting on the charged opaque particles, the third electrode being arranged on the second transparent substrate or on the ribs and the fourth electrode being arranged on the second transparent substrate, the voltages applied to the first electrode, the second electrode, the third electrode and the fourth electrode being controllable to have one of at least a first and a second value, wherein it includes a pulse driver for selectively applying voltage pulses to the first electrode, the second electrode, the third electrode, and the fourth electrode, the voltages applied to the first electrode and the second electrode being controllable to have the same or different values.