Issued Patents 2004
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 6740202 | Speaker diaphragm and method of manufacturing same | Toshihiro Ishigaki, Hideo Sekikawa, Tomoyuki Shimada | 2004-05-25 |
| 6681025 | Electromechanical and electroacoustic transducer | — | 2004-01-20 |