| # | Country | Total Patents | |
|---|---|---|---|
| #1 | Germany | 6 | |
| #2 | United Kingdom | 3 | |
| #3 | United States | 2 |
| # | Industry | |
|---|---|---|
| #1 | Consumer goods | |
| #2 | Optics |
| # | Technology | |
|---|---|---|
| #1 | Goods for writing upon | |
| #2 | Cameras |
| # | Name | Total Patents |
|---|---|---|
| #1 | Forster Fridolin | 7 |
| #2 | Fridolin Forster | 1 |
| Publication | Filing date | Title |
|---|---|---|
| US3483622A | Drawing apparatus | |
| GB1012207A | Drawing apparatus | |
| GB773932A | Apparatus for producing perspective drawings from plan view and elevation | |
| US2808758A | Projection apparatus for producing perspective drawings | |
| GB715088A | Improvements in or relating to photographic contact printing apparatus |