| # | Country | Total Patents | |
|---|---|---|---|
| #1 | France | 7 | |
| #2 | United Kingdom | 3 | |
| #3 | Switzerland | 2 | |
| #4 | Canada | 1 | |
| #5 | Spain | 1 |
| # | Industry | |
|---|---|---|
| #1 | Audio-visual technology | |
| #2 | Basic communication technologies | |
| #3 | Civil engineering |
| # | Technology | |
|---|---|---|
| #1 | Special information storage | |
| #2 | Swimming pools | |
| #3 | Tuning resonant circuits |
| # | Name | Total Patents |
|---|---|---|
| #1 | Ricchiardi Pier Carlo | 1 |
| #2 | A Reterson-Holding S | 1 |
| #3 | A Reterson Holding S | 1 |
| Publication | Filing date | Title |
|---|---|---|
| GB496530A | Improvements in record carriers for mechanical sound recording | |
| GB510204A | Improvements in or relating to electro-mechanical devices for recording and reproducing sound oscillations on an endless film | |
| GB505435A | Method and apparatus for the mechanical recording of sound oscillations | |
| CA394346A | Sound recording and reproducing device on endless films |