Issued Patents 1989
Showing 1–3 of 3 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4870349 | Digital level indicating device | Hiroshi Iizuka | 1989-09-26 |
| 4855741 | Logarithmic digital level display device | Hiroshi Iizuka | 1989-08-08 |
| 4805050 | Disk player information selecting apparatus | Yoshio Aoyagi, Tsuneo Ishii, Naoto Arifuku | 1989-02-14 |