Issued Patents All Time
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 6507578 | Channel division control equipment of the ISDN primary rate interface circuit | Sakae Nagayama, Kiyokazu Sanpei | 2003-01-14 |
| 6141343 | Channel division control equipment of the | Sakae Nagayama, Kiyokazu Sanpei | 2000-10-31 |