Issued Patents All Time
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 8480541 | User footfall sensing control system for treadmill exercise machines | — | 2013-07-09 |
| 5964821 | Mapless GPS navigation system with sortable destinations and zone preference | Douglas L. Welk | 1999-10-12 |
| 5887269 | Data product authorization control for GPS navigation system | Douglas L. Welk | 1999-03-23 |
| 5774828 | Mapless GPS navigation system with user modifiable data base | Douglas L. Welk | 1998-06-30 |
| 5724316 | GPS based time determining system and method | — | 1998-03-03 |
| 5627547 | Mapless GPS navigation system in vehicle entertainment system | Ashok B. Ramaswamy | 1997-05-06 |