Issued Patents 1989
Showing 1–1 of 1 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4889442 | Writing instrument with ink quantity of level detecting function | Hiroshi Takagi, Toshiaki Serikawa | 1989-12-26 |
Showing 1–1 of 1 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4889442 | Writing instrument with ink quantity of level detecting function | Hiroshi Takagi, Toshiaki Serikawa | 1989-12-26 |