Issued Patents All Time
Showing 51–72 of 72 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5286583 | Method of manufacturing a photomask for an optical memory | Junji Hirokane, Michinobu Mieda, Kenji Ohta | 1994-02-15 |
| 5260150 | Photo-mask with light shielding film buried in substrate | Kenji Ohta, Junji Hirokane, Akira Shibata, Yoshiyuki Nagahara, Kazuo Van +1 more | 1993-11-09 |
| 5170390 | Optical recording element and driving system | Kenji Ohta, Hiroyuki Katayama, Akira Takahashi, Junji Hirokane, Yukinori Nishitani +2 more | 1992-12-08 |
| 5128922 | Optical disk with glass substrate and method of producing same | Junji Hirokane, Akira Shibata, Yoshiyuki Nagahara, Kenji Ohta | 1992-07-07 |
| 5112727 | Method of and photomask for manufacturing optical memory element | Junji Hirokane, Akira Shibata, Yoshiyuki Nagahara, Kenji Ohta | 1992-05-12 |
| 5107486 | Optical memory device with grooves and pits in selected dimensional relationship | Junji Hirokane, Toshihisa Deguchi, Kenji Ohta | 1992-04-21 |
| 5087535 | Method of manufacturing photo-mask and photo-mask manufactured thereby | Junji Hirokane, Hiroyuki Katayama, Akira Takahashi, Kenji Ohta, Junichi Washo +3 more | 1992-02-11 |
| 5079113 | Photo-mask | Kenji Ohta, Junji Hirokane, Akira Shibata, Yoshiyuki Nagahara, Kazuo Van +1 more | 1992-01-07 |
| 4946730 | Method of and photomask for manufacturing optical memory element | Junji Hirokane, Akira Shibata, Yoshiyuki Nagahara, Kenji Ohta | 1990-08-07 |
| 4925776 | Optical memory element and manufacturing method thereof | Kenji Ohta, Junji Hirokane, Akira Takahashi, Shohichi Katoh, Toshihisa Deguchi | 1990-05-15 |
| 4881216 | Optical head in an optical memory device | Toshihisa Deguchi, Yoshikazu Fujii, Kenji Ohta, Schohichi Katoh | 1989-11-14 |
| 4839251 | Photo-mask for use in manufacturing an optical memory disc, a method for making the photo-mask and a method for manufacturing the optical memory disc | Kenji Ohta, Akira Takahashi, Junji Hirokane, Hiroyuki Katayama | 1989-06-13 |
| 4818648 | Optical memory element | Kenji Ohta, Akira Takahashi, Hiroyuki Katayama, Junji Hirokane, Yoshiteru Murakami | 1989-04-04 |
| 4787076 | Optical disc tracking system with switching of tracking error signals at boundary between track guide and track address | Toshihisa Deguchi, Kenji Ohta, Shohichi Katoh | 1988-11-22 |
| 4778747 | Method of manufacturing optical memory element | Kenji Ohta, Akira Takahashi, Junji Hirokane, Toshihisa Deguchi | 1988-10-18 |
| 4764441 | Photo-mask for production of substrate for optical memory element | Kenji Ohta, Junji Hirokane, Akira Takahashi, Hiroyuki Katayama | 1988-08-16 |
| 4721368 | Optical system in a magneto-optical memory device | Toshihisa Deguchi, Yoshikazu Fujii, Hideyoshi Yamaoka | 1988-01-26 |
| 4667315 | Tight beam position controlling apparatus | Yoshikazu Fujii, Toshihisa Deguchi, Tohru Okuda | 1987-05-19 |
| 4660190 | Optical focus position control in optical disc apparatus | Yoshikazu Fujii, Toshihisa Deguchi, Hideyoshi Yamaoka | 1987-04-21 |
| 4658390 | Optical focus position control in an optical memory system | Yosikazu Fujii, Toshihisa Deguchi, Hideyoshi Yamaoka | 1987-04-14 |
| 4658393 | Optical memory disc | Kenji Ohta, Akira Takahashi, Takao Hyuga, Hideyoshi Yamaoka | 1987-04-14 |
| 4634617 | Optical memory disc | Kenji Ohta, Akira Takahashi, Takao Hyuga, Hideyoshi Yamaoka | 1987-01-06 |