Issued Patents All Time
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5913173 | Radio frequency device | Haruki Ohwaki, Hiroshi Nagai, Seiji Matsushita | 1999-06-15 |
| 4629429 | Abacus with each counter held in position by friction or magnetic attraction | — | 1986-12-16 |