Issued Patents 1989
Showing 1–3 of 3 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 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 |