Chiral smectic C or H liquid crystal electro-optical device
Liquid crystal display element
Alignment of ferroelectric LCDs Patent #: 4561726
ApplicationNo. 06/729420 filed on 05/01/1984
US Classes:428/1.26, Polyimide349/132, For parallel alignment428/473.5Of polyimide
ExaminersPrimary: Corbin, John K.
Assistant: Gallivan, Richard F.
Attorney, Agent or Firm
International ClassesC09K 19/02 (20060101)
C08G 73/00 (20060101)
C08G 73/10 (20060101)
G02F 1/13 (20060101)
G02F 1/1337 (20060101)
Foreign Application Priority Data1984-05-01 JP
AbstractOrientation control films are coated on a pair of transparent substrates on the side contiguous to the ferroelectric liquid crystal layer and rubbed for aligning molecules thereof. The films are made of a polyimide polymer prepared by ring closure by heating and dehydrating of a polyamic acid which is synthesized by condensing, for example, pyromellitic dianhydride with 4,4'-diaminoterphenyl. A contrast ratio of the ferroelectric liquid crystal element is improved while keeping a high response characteristic of the ferroelectric liquid crystal materials.