Issued Patents 2003
Showing 1–1 of 1 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 6633631 | Digital key telephone system and extension terminal device thereof | Toshiaki Tanaka, Hiroshi Mano, Yoshihito Nagano, Masayuki Tsurusaki, Takashi Watanabe +4 more | 2003-10-14 |