Showing 1–6 of 6 inventors
| Rank | Inventor | Primary Company | Patents |
|---|---|---|---|
| 1 | Shinya Kagei | Mitsui Mining & Smelting Co. | 7 |
| 2 | Yoshimi Hata | Mitsui Mining & Smelting Co. | 4 |
| 3 | Sadao Takubo | Takubo Machine Works Co. | 2 |
| #4 | Yoshima Hata | Mitsui Mining & Smelting Co. | 1 |
| #4 | Tetsuya Mitsumoto | Mitsui Mining & Smelting Co. | 1 |
| #4 | Hitohiko Ide | Mitsui Mining & Smelting Co. | 1 |