Issued Patents All Time
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4933768 | Sound reproducer | Tsutomu Ishikawa, Ryuichi Ogawa, Masaya Tanno, Hirofumi Okada, Takayuki Imaida | 1990-06-12 |
| 4905283 | Surround decoder | Tsutomu Ishikawa, Ryuichi Ogawa, Masaya Tanno | 1990-02-27 |