当代显示技术 第一章(12)

当代显示技术 第一章

Thermotropic: State of the liquid is determined by

temperature. All liquid crystal displays are of this

type.

Lyotropic:State of the liquid is determined by concentration.

Useful in biological systems.

Amphitropic: Both temperature and concentration are

important.

Shapes of the liquid crystal molecule:

Calamitic: Rod shape. All common LCDs are of this type.Discotic:Disk like shape.

Phases of liquid crystals:

Nematic (N): All the LC molecules point in the same

direction. All common LCD are of this type.

Smectic (Sm): The LC molecules point in the same direction

and form layers.

Cholesteric (Ch): Twist angle between molecules. Same as

chiral nematic.

Structures of the liquid crystal “crystal”:

In a perfect crystal, all the molecules are fixed in space and

orientation – no freedom