Issued Patents 1989
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4888613 | Method of and apparatus for processing exposed photographic films | Helmut Zangenfeind | 1989-12-19 |
| 4799076 | Apparatus for affording access to exposed but undeveloped films in a dark chamber | Helmut Zangenfeind, Gunther Domges | 1989-01-17 |