Issued Patents All Time
Showing 1–14 of 14 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 6339564 | Optical information recording/reproducing apparatus | Koichi Tezuka, Kyoko Miyabe, Tohru Fujimaki, Kazushi Uno | 2002-01-15 |
| 6278984 | Software processing apparatus writing software to a medium only if identification information in the software corresponds to identification information in the medium | Kazuo Nakashima, Kenichi Utsumi | 2001-08-21 |
| 6185166 | Optical information recording/reproducing apparatus | Koichi Tezuka, Kyoko Miyabe, Tohru Fujimaki, Kazushi Uno | 2001-02-06 |
| 6011764 | Optical disk and optical disk apparatus | Masaru Nakahara, Masahiro Nakada, Hiroshi Suzuki, Kenichi Utsumi | 2000-01-04 |
| 5982886 | Unauthorized use preventing method for optical disks, optical disk having unauthorized use prevention function, and optical disk apparatus | Kenichi Utsumi, Masahiro Nakada, Hiroshi Suzuki, Kazunori Naito, Kazuo Nakashima +2 more | 1999-11-09 |
| 5875247 | System for decrypting encrypted software | Kazuo Nakashima, Masaru Nakahara, Kenichi Utsumi | 1999-02-23 |
| 5809300 | Removable storage medium and computer system using the same | Kenichi Utsumi, Koichi Ogawa, Makoto Yoshioka, Kazunori Naito, Kazuo Nakashima | 1998-09-15 |
| 5793725 | Optical information recording/reproducing apparatus having a composite prism with a plurality of emission surfaces | Koichi Tezuka, Kyoko Miyabe, Tohru Fujimaki | 1998-08-11 |
| 5777965 | Optical disk having an erased-state indicator and optical disk apparatus for reducing frequency of disk-erasing operations | Masaru Nakahara, Masahiro Nakada, Hiroshi Suzuki, Kenichi Utsumi | 1998-07-07 |
| 5684785 | Optical disk and method of preventing fraudulent use of optical disk rotation synchronous control system | Kenichi Utsumi, Kazuo Nakashima, Kazunori Naito, Satoshi Komura | 1997-11-04 |
| 5623462 | Optical information recording/reproducing apparatus | Koichi Tezuka, Kyoko Miyabe, Tohru Fujimaki | 1997-04-22 |
| 5617393 | Optical disk having an erased-state indicator and optical disk apparatus for reducing frequency of disk erasing operation | Masaru Nakahara, Masahiro Nakada, Hiroshi Suzuki, Kenichi Utsumi | 1997-04-01 |
| 5418852 | Unauthorized use prevention method for optical disks, optical disk having unauthorized use prevention function, and optical disk apparatus | Kenichi Utsumi, Masahiro Nakada, Hiroshi Suzuki, Kazunori Naito, Kazuo Nakashima +2 more | 1995-05-23 |
| 5357431 | Character string retrieval system using index and unit for making the index | Masahiro Nakada, Kenichi Utsumi, Takashi Tsubokura, Masaru Nakahara, Hiroshi Suzuki +2 more | 1994-10-18 |