Inventor
ECKHARDT STEPHEN K
US23 patents
⚠️ This page may combine multiple inventors who share the name “ECKHARDT STEPHEN K”. Patents are grouped by organization below to help distinguish them — per-person disambiguation is on the roadmap.
3M INNOVATIVE PROPERTIES CO
14 patentsUS6721096B2Apr 13, 2004
Polarizing beam splitter
3M INNOVATIVE PROPERTIES CO198 citations99
US6486997B1Nov 26, 2002
Reflective LCD projection system using wide-angle Cartesian polarizing beam splitter
3M INNOVATIVE PROPERTIES CO348 citations99
US6719426B2Apr 13, 2004
Compound polarization beam splitters
3M INNOVATIVE PROPERTIES CO106 citations97
US6672721B2Jan 6, 2004
Projection system having low astigmatism
3M INNOVATIVE PROPERTIES CO41 citations96
US6976759B2Dec 20, 2005
Compound polarization beam splitters
3M INNOVATIVE PROPERTIES CO34 citations92
US6104536AAug 15, 2000
High efficiency polarization converter including input and output lenslet arrays
3M INNOVATIVE PROPERTIES CO45 citations92
US7804649B2Sep 28, 2010
Microreplicated achromatic lens
3M INNOVATIVE PROPERTIES CO11 citations84
US7684126B2Mar 23, 2010
Fresnel field lens
3M INNOVATIVE PROPERTIES CO8 citations84
US7411734B2Aug 12, 2008
Color-splitting optical element and an optical system utilizing the color-splitting optical element
3M INNOVATIVE PROPERTIES CO11 citations84
US7329006B2Feb 12, 2008
Projection system having low astigmatism
3M INNOVATIVE PROPERTIES CO11 citations84
US6857752B2Feb 22, 2005
Projection illumination system with tunnel integrator and field lens
3M INNOVATIVE PROPERTIES CO13 citations84
US7152981B2Dec 26, 2006
Projection illumination system with tunnel integrator and field lens
3M INNOVATIVE PROPERTIES CO6 citations74
US7475991B2Jan 13, 2009
Polarizing beamsplitter assembly
3M INNOVATIVE PROPERTIES CO7 citations71
US9816679B2Nov 14, 2017
Light assembly
3M INNOVATIVE PROPERTIES CO0 citations51
MINNESOTA MINING & MFG
5 patentsUS5596455AJan 21, 1997
Fixed-focus triplet projection lens for overhead projectors
MINNESOTA MINING & MFG22 citations92
US5803568ASep 8, 1998
Dual grooved Fresnel lens for overhead projection
MINNESOTA MINING & MFG9 citations74
US5400094AMar 21, 1995
Condensers for overhead projectors
MINNESOTA MINING & MFG4 citations63
US5515123AMay 7, 1996
Condensers for illumination systems
MINNESOTA MINING & MFG5 citations62
US5475535ADec 12, 1995
Condensers for overhead projectors
MINNESOTA MINING & MFG1 citations52