Ferroelectric liquid crystal cell with rubbed polyimide alignment layer
US4634228A · kind A · utility
40Cited by
3References
3Claims
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Key dates
| Filing date | May 1, 1984 |
| Grant date | Jan 6, 1987 |
| Priority date | — |
| Expiry date | May 1, 2004 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31721
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
Orientation 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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.