| # | Country | Total Patents | |
|---|---|---|---|
| #1 | Germany | 5 | |
| #2 | United States | 3 | |
| #3 | Switzerland | 1 | |
| #4 | United Kingdom | 1 | |
| #5 | Italy | 1 |
| # | Industry | |
|---|---|---|
| #1 | Measurement | |
| #2 | Audio-visual technology | |
| #3 | Optics |
| # | Technology | |
|---|---|---|
| #1 | Analysing materials | |
| #2 | Casings and printed circuits | |
| #3 | Measuring light | |
| #4 | Optical systems |
| # | Name | Total Patents |
|---|---|---|
| #1 | Eickhorst Manfred | 9 |
| #2 | Manfred Eickhorst | 1 |
| #3 | Lenzen Godehard Dr | 1 |
| Publication | Filing date | Title |
|---|---|---|
| GB2085611A | Refractometer for testing gemstones | |
| US3989379A | Apparatus for the spectroscopical examination of light transmitting objects such as precious stones | |
| US3950102A | Analysis lamp, particularly for the examination of precious stones | |
| DE2452837A1 | Spectroscope for analysis of gemstones - has flat transparent platform for gemstone under test situated at intersection of two optical axes | |
| US3872995A | Box-like casing cell |