| 摘要 |
The invention relates to a liquid crystalline compound of the formula I wherein X<1 >and R<1 >are defined as in claim 1. The invention further relates to a liquid crystalline medium based on a mixture of polar compounds of positive dielectric anisotropy containing one or more compounds of formula I and its use in electrooptical displays and projection systems, in particular reflective displays and displays based on a birefringence effect, such as OCB displays. |
