Patent ID: 7755707

Claim:
A display device, comprising a controllable LC layer ( 21 ) a birefringent lens layer ( 22 ), comprising a number of cylindrical lenses, extending in a main direction, and a rotator layer ( 25 ′) providing a polarisation twist for rotating the polarisation direction of light rays, received from the LC layer ( 21 ), in such a way that it is parallel with or perpendicular to the main direction, the lens layer ( 22 ) refracting said light rays differently depending on their direction of polarisation, and a switchable birefringent layer ( 23 ′) receiving light rays from the lens layer ( 22 ) and providing a variable amount of polarising twist to these rays in order to select an operation mode for the birefringent lens layer ( 22 ), wherein a birefringent compensation layer ( 26 ) is placed between the birefringent lens layer ( 22 ) and the switchable birefringent layer ( 23 ′), the birefringent compensation layer ( 26 ) providing a polarisation change that is substantially equal in amount and is opposite in direction as compared to the polarisation change of the rotator layer ( 25 ′).