Blue Phase LCD technology
Blue Phase – another approach for LC displays
Behind the technology
The Blue Phase (BP) can occur between the chiral nematic phase (the phase in which the liquid crystals are also twisted) and the isotropic phase. Blue Phase has optically isotropic properties because of its complex structure.
The birefringent properties needed to change the transmission are also induced by electric fields in a blue phase display (BPD), also known as a blue mode display (BMD). The key advantage of Blue Phase is the extremely fast switching times, which can be less than a millisecond. Another benefit: the BP liquid crystals in the display do not need to be aligned with orientation layers, removing the need for this technical expense. This is because the BP already appears optically isotropic and the liquid crystals are aligned only by the electric field. Orientation layers and the associated production processes are therefore unnecessary in a BPD. The direction of the electric field must be parallel to the glass substrate so that the aligned liquid crystals can induce visible birefringence. The birefringence value depends on the voltage applied, making it possible to control the transmission of the display. Polymer stabilization of the BP expands the narrow temperature range of only around 3 Kelvins in which the blue phase typically occurs to up to 100 Kelvins.