Issued Patents All Time
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 6824295 | Emergency lighting device | — | 2004-11-30 |
| 6026602 | Apparatus and method of indirectly illuminating a sign | Robert M. Johnstone | 2000-02-22 |
| 5542201 | Indirectly illuminated sign | Robert M. Johnstone | 1996-08-06 |
| 5428912 | Indirectly illuminated sign | Robert M. Johnstone | 1995-07-04 |
| 5299109 | LED exit light fixture | — | 1994-03-29 |