Issued Patents 1989
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4823377 | System for setting registration mode for key telephone set | Kenichi Kanno, Hisami Ojima | 1989-04-18 |
| 4821316 | Key telephone system | Senji Okumura, Yasuo Kobayashi, Masatoshi Ikeda | 1989-04-11 |