Method of determining the pretilt angle of liquid crystal molecules
US5172187A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 5, 1991 |
| Grant date | Dec 15, 1992 |
| Priority date | — |
| Expiry date | Apr 5, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02F1/1309
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
The invention concerns a method of determining the angle of attack (pretilt angle) of liquid crystal molecules in a liquid crystal display (LCD) provided with top and bottom cover plates. The following steps are proposed for a simple and cheap determination: addition of a dichroic dye (17) to the liquid crystal (5) in order to cause the dye molecules (18) to become aligned by the crystal molecules (6), which are present in a twist-free state, determination by measurement of a maximum absorption value, the said measurement being carried out by causing a polarized ray of light (19) (measuring ray) to pass through the liquid crystal display (1) and varying its angle of inclination (.alpha.) with respect to the plane of the cover plates (2,3), and then using the angle of inclination (.alpha.) associated with the maximum absorption for determining the angle of attack (.delta.).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.