Patent US 4674841A
| Patent number | US 4674841A (click link for details and documents via Google Patents) |
|---|---|
| Title | Color filter switchable among three state via a variable retarder |
| Inventors | Thomas S. Buzak |
| Company | Tektronix Inc |
| Filing date | 1985-03-08 |
| Grant date | 1987-06-23 |