Issued Patents All Time
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5153482 | High-pressure sodium discharge lamp | Robertus A. J. Keijser | 1992-10-06 |
| 5097176 | High-pressure sodium discharge lamp having a color temperature of at least 2800.degree. K. | Johannes T. W. De Hair, Johannes H. M. Van Der Sande, Robertus A. J. Keijser | 1992-03-17 |