| 摘要 |
<p>To determine the tilt angle ?<SUB>tilt</SUB> in a twisted nematic liquid-crystal cell, the transmission of the cell is calculated as a function of the angle of incidence a of a light ray of given wavelength l using the apparent values of the thickness d of the cell cavity, the extraordinary index n<SUB>e</SUB> and the twist angle ?<SUB>twist</SUB>. To obtain a plurality of simulation curves Sim1, Sim2, one per given pretilt angle ?<SUB>tilt</SUB>, the transmission curve M(C) as a function of the angle of incidence of the cell along the YY' axis, passing through the high T and low B positions of the cell, is measured for the light ray of wavelength l, using a contrast measurement device, and the coincidence of this measurement curve with one among the plurality of simulation curves gives the pretilt angle of this cell.</p> |
