Issued Patents All Time
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5039916 | Operating circuit for a high-pressure discharge lamp | Ralf Schafer, Steven Kemmink, Hilbert Palmers | 1991-08-13 |
| 4795943 | High-pressure sodium vapor discharge lamp | Petrus H. Antonis, Ralf Schafer | 1989-01-03 |