Issued Patents 2004
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 6731721 | Telephone exchange apparatus | Toshiaki Tanaka, Shuji Fujitsuka, Takashi Aoki | 2004-05-04 |
| 6687361 | Electronic exchange and key telephone system | Tamotsu Wakabayashi, Masashi Ishida, Katsunori Utsumi | 2004-02-03 |