Issued Patents 1989
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4889757 | Optical recording disk | Shinkichi Horigome, Norio Ohta, Yutaka Sugita, Yoshinori Miyamura, Ryoichi Sudo +2 more | 1989-12-26 |
| 4880694 | Magneto-optical recording material | Shinji Takayama, Katsuhiro Kaneko, Yutaka Sugita | 1989-11-14 |