Issued Patents 1989
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4811147 | Magnetic head incorporating a glass composition of barium oxide and phosphorous pentaoxide | Kazuaki Koyama, Isao Yasuda | 1989-03-07 |
| 4807075 | Magnetic head | Kazuaki Koyama, Isao Yasuda | 1989-02-21 |