| # | Country | Total Patents | |
|---|---|---|---|
| #1 | Denmark | 23 | |
| #2 | Austria | 5 | |
| #3 | United Kingdom | 4 | |
| #4 | Switzerland | 2 | |
| #5 | Canada | 1 |
| # | Industry | |
|---|---|---|
| #1 | Audio-visual technology | |
| #2 | Telecommunications |
| # | Technology | |
|---|---|---|
| #1 | Loudspeakers and microphones | |
| #2 | Secret communication | |
| #3 | Special information storage |
| # | Name | Total Patents |
|---|---|---|
| #1 | Tigerstedt Eric Magnus Campbel | 33 |
| #2 | Magnus Campbell Tigerstedt Eri | 2 |
| Publication | Filing date | Title |
|---|---|---|
| GB130600A | Diaphragm for Reception and Reproduction of Sound. | |
| GB100748A | Improvements relating to the Combined use of Kinematographs and Talking Machines. | |
| GB191505174A | Microphone. | |
| GB191504912A | Transmission of Sound Waves. | |
| CA220993A | Apparatus for transmitting signals |