Issued Patents 1989
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4853260 | Optical disk and process for producing the same | Toshikazu Yoshino, Ryutaro Hayashi | 1989-08-01 |
| 4847827 | Optical information recording disk | Ryutaro Hayashi, Toshikazu Yoshino | 1989-07-11 |