Issued Patents 1997
Showing 1–4 of 4 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5702645 | Photochromic chromene derivatives | — | 1997-12-30 |
| 5679805 | Photochromic spironaphthopyran compounds | — | 1997-10-21 |
| 5658502 | Photochromic articles | — | 1997-08-19 |
| 5628935 | Photochromic spironaphthopyran compounds | Edward A. Travnicek | 1997-05-13 |