Method of determining the pretilt angle in a liquid-crystal cell
US7855787B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Nov 20, 2007 |
| Grant date | Dec 21, 2010 |
| Priority date | — |
| Expiry date | Nov 21, 2027 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02F1/1309
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
To determine the tilt angle in a twisted nematic liquid-crystal cell, the transmission of the cell is calculated as a function of the angle of incidence of a light beam of given wavelength λ using apparent values of the thickness of the cell cavity, of the extraordinary index and of the twist angle, in order to obtain a plurality of simulation curves, one per given pretilt angle, the transmission curve is measured as a function of the angle of incidence of the cell along the axis passing through the top and bottom positions of the cell, for the light beam of wavelength λ, using a contrast meter, and the coincidence between this measurement curve and a curve from among the plurality of simulation curves gives the pretilt angle of this cell.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.