Patent ID: 11927863
Assignee: COMMISSARIAT A L'ENERGIE ATOMIQUE ET AUX ENERGIES ALTERNATIVES
Field: Optics (Instruments)
Classification: CPC G | IPC G

Claim 14:
15. A device for modulating a phase of a light beam, comprising:
a matrix of elementary cells, called pixels, coupled to a circuit for addressing said pixels, each elementary cell comprising a liquid crystal layer (CL) and, on either side of said liquid crystal layer, at least one first electrode (ELP) called pixel electrode controlled by at least one control transistor coupled to said addressing circuit, and a second electrode (EL2) that is transparent and common to all the cells,
the liquid crystal being composed of molecules having a natural orientation of rest in a plane of said device and in a so-called horizontal direction of alignment (Xa) oriented along a so-called horizontal row of pixels, and in the absence of voltage between the at least one pixel electrode and the second electrode, and another orientation outside of said plane of said device in the presence of voltage between the at least one pixel electrode and the second electrode, called activation voltage (Vact), said activation voltage being applied in a phase of activation of the liquid crystal molecules,
the device further comprising a set of so-called lateral electrodes extending in a so-called vertical direction (Y) at right angles to said alignment direction (Xa), disposed on a same plane as the pixel electrode and configured to apply, for each pixel and via at least two lateral electrodes, a so-called acceleration voltage (Vacc) generating a lateral electrical field (Era) substantially parallel to said alignment direction, in a vector allowing an accelerated return of the liquid crystal molecules to their orientation of rest, said acceleration voltage being configured to be applied in a phase called accelerated relaxation phase, when the activation voltage is no longer applied,
wherein the lateral electrodes are thin strips disposed on either side of wider strips forming the pixel electrode or electrodes and wherein the acceleration voltage is applied between two adjacent lateral electrodes (EL1(i), EL1(i+1)).