Issued Patents All Time
Showing 1–4 of 4 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4754477 | Key telephone system | Kouji Tanaka, Yoshihiro Ikeda, Ryuzo Sugiura, Hikaru Sano | 1988-06-28 |
| 4572928 | Key telephone system | Tomio Nishimura, Ryuzo Sugiura, Toshiro Yoshida | 1986-02-25 |
| 4514597 | Control of a key telephone system using a pulse width modulated signal | Ryuzo Sugiura, Mutsuhiro Yamamoto, Toshiro Yoshida | 1985-04-30 |
| 4383137 | Key telephone system with multiple processor control | Chuta Aikawa, Noriyoshi Sanada, Mitsuyoshi Murakami, Masaki Kuroda | 1983-05-10 |