Issued Patents All Time
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4696877 | Photo-mask blank comprising a shading layer having a variable etch rate | Shigekazu Matsui, Masao Ushida, Kouichi Maruyama | 1987-09-29 |
| 4563407 | Photo-mask blank comprising a shading layer having a variable etch rate | Shigekazu Matsui, Masao Ushida, Kouichi Maruyama | 1986-01-07 |