Issued Patents All Time
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4889442 | Writing instrument with ink quantity of level detecting function | Hiroshi Takagi, Noriaki Tsunoda | 1989-12-26 |
| 4722124 | Method of manufacturing the writing tip of a ball point pen | Hiroshi Takagi | 1988-02-02 |