Issued Patents All Time
Showing 1–3 of 3 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5099474 | Digital exchange and its control method | Eiji Ohtsuka | 1992-03-24 |
| 4995033 | Digital private branch exchange and method of manufacturing same | — | 1991-02-19 |
| 4953195 | Private branch exchange system with specific information transmitting function | — | 1990-08-28 |