David Shafer
134Patents
31h-index
66Co-inventors
93Inventor score
Filing activity: Aug 18, 1977 → Sep 30, 2019
Most-cited inventions
| Patent | Title | Area | Cited by | Status |
|---|---|---|---|---|
| US5999310A | Ultra-broadband UV microscope imaging system with wide range zoom capability | Physics | 159 | Expired |
| US5717518A | Broad spectrum ultraviolet catadioptric imaging system | Physics | 146 | Expired |
| US5686728A | Projection lithography system and method using all-reflective optical elements | Physics | 117 | Expired |
| US4747678A | Optical relay system with magnification | Physics | 93 | Expired |
| US6636350B2 | Microlithographic reduction projection catadioptric objective | Physics | 91 | Expired |
| US5031976A | Catadioptric imaging system | Emerging Cross-Sectional Technologies | 86 | Expired |
| US5559338A | Deep ultraviolet optical imaging system for microlithography and/or microfabrication | Physics | 83 | Expired |
| US6142641A | Four-mirror extreme ultraviolet (EUV) lithography projection system | Physics | 83 | Expired |
| US6064517A | High NA system for multiple mode imaging | Physics | 83 | Expired |
| US6600608B1 | Catadioptric objective comprising two intermediate images | Physics | 77 | Expired |
| US5353322A | Lens system for X-ray projection lithography camera | Physics | 74 | Expired |
| US5488229A | Deep ultraviolet microlithography system | Physics | 74 | Expired |
| US6204961A | Day and night sighting system | Physics | 69 | Expired |
| US6188513A | High numerical aperture ring field projection system for extreme ultraviolet lithography | Physics | 61 | Expired |
| US5410434A | Reflective projection system comprising four spherical mirrors | Physics | 60 | Expired |
| US5220590A | X-ray projection lithography camera | Physics | 59 | Expired |
| US4469414A | Restrictive off-axis field optical system | Physics | 58 | Expired |
| US4226501A | Four mirror unobscurred anastigmatic telescope with all spherical surfaces | Physics | 56 | Expired |
| US6873476B2 | Microlithographic reduction projection catadioptric objective | Physics | 56 | Expired |
| US6842298B1 | Broad band DUV, VUV long-working distance catadioptric imaging system | Physics | 51 | Expired |
| US4711535A | Ring field projection system | Physics | 47 | Expired |
| US5973826A | Reflective optical imaging system with balanced distortion | Physics | 47 | Expired |
| US6014252A | Reflective optical imaging system | Emerging Cross-Sectional Technologies | 46 | Expired |
| US7218445B2 | Microlithographic reduction projection catadioptric objective | Physics | 45 | Expired |
| US6262836A | High numerical aperture ring field projection system for extreme ultraviolet lithography | Physics | 42 | Expired |
Source: USPTO / EPO open patent data. Inventor disambiguation is heuristic; counts are objective bibliographic measures.