Issued Patents 2004
Showing 1–4 of 4 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 6778344 | Recording medium and apparatus for protecting copyrighted digital data | Koichi Sugiyama | 2004-08-17 |
| 6744584 | Recording medium and apparatus for protecting copyrighted digital data | Koichi Sugiyama | 2004-06-01 |
| 6744588 | Recording medium and apparatus for protecting copyrighted digital data | Koichi Sugiyama | 2004-06-01 |
| 6687076 | Recording medium and apparatus for protecting copyrighted digital data | Koichi Sugiyama | 2004-02-03 |