Stephen K. Eckhardt
23Patents
8h-index
30Co-inventors
75Inventor score
Filing activity: Mar 31, 1993 → Oct 29, 2015
Most-cited inventions
| Patent | Title | Area | Cited by | Status |
|---|---|---|---|---|
| US6486997B1 | Reflective LCD projection system using wide-angle Cartesian polarizing beam splitter | Performing Operations; Transporting | 246 | Expired |
| US6721096B2 | Polarizing beam splitter | Performing Operations; Transporting | 159 | Expired |
| US6719426B2 | Compound polarization beam splitters | Physics | 67 | Expired |
| US6976759B2 | Compound polarization beam splitters | Physics | 32 | Expired |
| US6104536A | High efficiency polarization converter including input and output lenslet arrays | Physics | 26 | Expired |
| US6672721B2 | Projection system having low astigmatism | Electricity | 19 | Expired |
| US5596455A | Fixed-focus triplet projection lens for overhead projectors | Physics | 9 | Expired |
| US7411734B2 | Color-splitting optical element and an optical system utilizing the color-splitting optical element | Electricity | 8 | Expired |
| US7329006B2 | Projection system having low astigmatism | Electricity | 7 | Expired |
| US7684126B2 | Fresnel field lens | Physics | 6 | Active |
| US6857752B2 | Projection illumination system with tunnel integrator and field lens | Emerging Cross-Sectional Technologies | 6 | Expired |
| US7804649B2 | Microreplicated achromatic lens | Physics | 5 | Expired |
| US5803568A | Dual grooved Fresnel lens for overhead projection | Physics | 4 | Expired |
| US8721153B2 | Backlight reflectors having a prismatic structure | Emerging Cross-Sectional Technologies | 4 | Active |
| US5400094A | Condensers for overhead projectors | Emerging Cross-Sectional Technologies | 3 | Expired |
| US9200775B2 | Light assembly | Mechanical Engineering; Lighting; Heating | 3 | Active |
| US5515123A | Condensers for illumination systems | Physics | 3 | Expired |
| US7152981B2 | Projection illumination system with tunnel integrator and field lens | Emerging Cross-Sectional Technologies | 3 | Expired |
| US7475991B2 | Polarizing beamsplitter assembly | Electricity | 2 | Active |
| US5475535A | Condensers for overhead projectors | Emerging Cross-Sectional Technologies | 1 | Expired |
| US8675194B2 | Apparatus for measuring the retroreflectance of materials | Physics | 0 | Active |
| US9229200B2 | Panoramic optical systems | Physics | 0 | Active |
| US9816679B2 | Light assembly | Mechanical Engineering; Lighting; Heating | 0 | Active |
Source: USPTO / EPO open patent data. Inventor disambiguation is heuristic; counts are objective bibliographic measures.