Issued Patents 2002
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 6490113 | Recording medium and apparatus for protecting copyrighted digital data | Koichi Sugiyama | 2002-12-03 |
| 6437933 | Recording medium for protecting copyrighted data | Koichi Sugiyama | 2002-08-20 |