Patent ID: 7894018

Claim:
A method for producing a liquid crystal material that can be addressed by an electric field, characterised in that it comprises the steps of: Forming a liquid crystal mixture with a helical structure comprising a first non-photoreactive liquid crystal (A) and a second photoreactive liquid crystal (B), the first liquid crystal (A) comprising first chiral liquid crystal molecules (A 1 ) and the first liquid crystal (A) having a positive dielectric anisotropy, and the second liquid crystal (B) being in a concentration of less than or equal to 5% of the mixture; Applying a first treatment to the liquid crystal mixture, the first treatment being carried out at constant temperature and modifying a pitch of the helix of the mixture without modifying a handedness of the helix; Applying a second treatment to the mixture such that the second liquid crystal (B) forms a polymer network, the second treatment being performed during all or part of the first treatment such that the liquid crystal material keeps a memory of the modifications to the pitch of the helix.