Issued Patents 1989
Showing 1–1 of 1 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4849837 | Method of, and apparatus for, recording audio signals using recording signals free of audio frequencies | — | 1989-07-18 |
Showing 1–1 of 1 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4849837 | Method of, and apparatus for, recording audio signals using recording signals free of audio frequencies | — | 1989-07-18 |