Issued Patents All Time
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5163844 | Battery-free electronic teaching apparatus with keypad of piezo film switches | Richard A. Houghton, Richard H. Wallace | 1992-11-17 |
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5163844 | Battery-free electronic teaching apparatus with keypad of piezo film switches | Richard A. Houghton, Richard H. Wallace | 1992-11-17 |