Issued Patents All Time
Showing 1–4 of 4 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4551583 | Control signal transmission system for key telephone system | Koichi Sekiguchi, Kazuyuki Yamamoto, Teruyuki Kubo | 1985-11-05 |
| 4353066 | Channel switching network | Tetsuro Inomata, Kazutada Katsukura | 1982-10-05 |
| 4280022 | Key telephone systems | Koichi Sekiguchi, Kazutada Tatsukura | 1981-07-21 |
| 4234765 | Key telephone system | Kouichi Sekiguchi, Kazutada Katsukura | 1980-11-18 |