Issued Patents 1989
Showing 1–1 of 1 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4859501 | Method for providing a perpendicular recording medium for use with a ring-shaped recording and reproducing head | Ryuji Sugita, Kiyokazu Tohma, Kazuyoshi Honda | 1989-08-22 |