Issued Patents 1989
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 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, Tetsuya Inui, Junji Hirokane | 1989-06-13 |
| 4818648 | Optical memory element | Kenji Ohta, Akira Takahashi, Tetsuya Inui, Junji Hirokane, Yoshiteru Murakami | 1989-04-04 |