Issued Patents 1989
Showing 1–3 of 3 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4889412 | Liquid crystal cell using the electrically controlled birefringence effect and a uniaxial medium of negative optical anisotropy usable therein | Jean-Frederic Clerc, Pierre Vaudaine, Sylvie Vey | 1989-12-26 |
| 4870263 | Device for determining the contrast of a display screen as a function of the observation direction | — | 1989-09-26 |
| 4813770 | Cell with a double liquid crystal layer using the electrically controlled birefringence effect and process for producing a uniaxial medium with negative optical anisotropy usable in said cell | Jean-Frederic Clerc, Aime Perrin | 1989-03-21 |