Issued Patents 1989
Showing 1–3 of 3 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4879691 | Optical recording system with optical recording medium having multilevel recording surface for tracking | — | 1989-11-07 |
| 4831609 | Tracking method and apparatus for optical recording medium | — | 1989-05-16 |
| 4815062 | Write-once data writing system for optical recording medium | — | 1989-03-21 |