Issued Patents All Time
Showing 1–4 of 4 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5023929 | Audio frequency based market survey method | — | 1991-06-11 |
| 4912466 | Audio frequency based data capture tablet | — | 1990-03-27 |
| 4335303 | Method for collecting market survey data from universal product type coded items | — | 1982-06-15 |
| 4290688 | Apparatus for collecting market survey data from universal product type coded items | — | 1981-09-22 |