| # | Country | Total Patents | |
|---|---|---|---|
| #1 | Germany | 44 | |
| #2 | Switzerland | 41 | |
| #3 | United Kingdom | 9 | |
| #4 | United States | 9 | |
| #5 | Austria | 7 | |
| #6 | France | 4 | |
| #7 | Canada | 1 |
| # | Industry | |
|---|---|---|
| #1 | Optics | |
| #2 | Organic fine chemistry | |
| #3 | Engines, pumps and turbines |
| # | Technology | |
|---|---|---|
| #1 | Optical systems | |
| #2 | Photosensitive materials | |
| #3 | Supplying combustion engines | |
| #4 | Acyclic or carbocyclic compounds |
| # | Name | Total Patents |
|---|---|---|
| #1 | Bertele Ludwig | 39 |
| #2 | Bertele Ludwig Dr | 26 |
| #3 | Ludwig Bertele | 18 |
| #4 | Juergen Bertele | 7 |
| #5 | Ludwig Bertele Dr | 4 |
| #6 | Bertele Dr Ludwig | 3 |
| #7 | Bertele Juergen | 3 |
| #8 | Ludwig Beck | 2 |
| #9 | Bertele Jurgen | 1 |
| #10 | Beutele Ludwig Dr | 1 |
| Publication | Filing date | Title |
|---|---|---|
| CH611431A5 | Lens of variable focal length having a diverging front element | |
| DE2620336A1 | LENS CHANGEABLE FOCAL LENGTH WITH DIVERSING FRONT PANEL | |
| DE2525100A1 | VARIO LENS WITH SLIDING LENS LINK WITH POSITIVE BREAKING FORCE | |
| DE2114073A1 | Lens with adjustable focal length | |
| DE2112193A1 | Lens consisting of at least four lens elements | |
| DE1923957A1 | Photographic lens | |
| DE1918796A1 | Wide angle lens | |
| DE1915396A1 | Wide angle lens | |
| US3597048A | Varifocal objective with movable lens component of positive refractivity | |
| DE1772185A1 | Wide angle lens | |
| GB1137788A | Wide angle lens | |
| DE1223576B | Wide angle lens | |
| CH427334A | Lens changeable focal length | |
| DE1185839B | Telescope system | |
| DE1088247B | Four-element lens | |
| DE1097708B | Photographic lens | |
| DE1097709B | Wide angle lens | |
| DE1051528B | Photographic lens | |
| DE1025641B | Three-part lens | |
| DE1020809B | lens |