Issued Patents All Time
Showing 1–4 of 4 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 12421411 | Aqueous ink composition for reversibly thermochromic writing instrument, and refill and aqueous ballpoint pen incorporating aqueous ink composition for reversibly thermochromic writing instrument | Mamiko Ogura, Itsuka Ohno | 2025-09-23 |
| 11975560 | Ballpoint pen tip, ballpoint pen refill, and ballpoint pen | Takumi Kajiwara | 2024-05-07 |
| 10556459 | Writing instrument for forming thermochromic handwriting | Takumi Kajiwara | 2020-02-11 |
| 9375972 | Writing instrument | Hirotaka Masuda | 2016-06-28 |