Issued Patents 1989
Showing 1–1 of 1 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4842969 | Transmittance modulation photomask, process for producing the same, and process for producing diffraction gratings using the same | Katsuya Fujisawa, Ichiro Matsuzaki, Masao Uetsuki | 1989-06-27 |