Issued Patents All Time
Showing 26–28 of 28 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4677692 | Frequency conversion apparatus | Seiji Sakashita, Takeshi Sato, Hiroyuki Nagai, Akira Usui | 1987-06-30 |
| 4647499 | Shaped body of calcium silicate and process for producing same | Akira Takahashi, Kazuo Shibahara, Katsuhiro Morimoto, Hiromasa Samma | 1987-03-03 |
| 4298386 | Calcium silicate and process for producing same | Akira Takahashi, Kenichi Oohashi | 1981-11-03 |