| # | Country | Total Patents | |
|---|---|---|---|
| #1 | United States | 12 |
| # | Industry | |
|---|---|---|
| #1 | Electrical machinery and energy | |
| #2 | Medical technology | |
| #3 | Audio-visual technology | |
| #4 | Machines |
| # | Technology | |
|---|---|---|
| #1 | Diagnosis and surgery | |
| #2 | Non-portable lighting devices | |
| #3 | Lighting device details | |
| #4 | Advertising | |
| #5 | Unspecified technologies |
| # | Name | Total Patents |
|---|---|---|
| #1 | Errol Ferree Clarence | 12 |
| #2 | Rand Ferree Gertrude | 10 |
| Publication | Filing date | Title |
|---|---|---|
| US2124229A | Central vision scotometer | |
| US1986052A | Variable intensity lamp | |
| US2033235A | Direct lighting unit | |
| US2045704A | Ophthalmic instrument | |
| US1899499A | Lectern lighting unit | |
| US1906559A | Lighting unit | |
| US1894583A | Lighting unit | |
| US1609870A | Indirect-lighting fixture | |
| US1596725A | Lighting fixture | |
| US1693979A | Perimeter | |
| US1558348A | Method of and apparatus for vision testing, etc. | |
| US1526781A | Tachistoscope |