Issued Patents 2005
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 6894860 | Recording medium and apparatus for protecting copyrighted digital data | Koichi Sugiyama | 2005-05-17 |
| 6873485 | Recording medium and apparatus for protecting copyrighted digital data | Koichi Sugiyama | 2005-03-29 |