Issued Patents 1989
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4872156 | Record carrier with a preformed information track for recording information with a radiation beam | Dirk J. Gravesteijn | 1989-10-03 |
| 4802154 | High density codes for optical recording | Johannes J. Verboom | 1989-01-31 |