Issued Patents 1989
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4859567 | Method of forming high contrast negative images | Eiichi Okutsu | 1989-08-22 |
| 4833064 | Process for the formation of a high contrast negative image | Eiichi Okutsu, Morio Yagihara, Katsumi Hayashi | 1989-05-23 |