Inventor
VANDERWERF DENNIS F
28 patents
⚠️ This page may combine multiple inventors who share the name “VANDERWERF DENNIS F”. Patents are grouped by organization below to help distinguish them — per-person disambiguation is on the roadmap.
MINNESOTA MINING & MFG
22 patentsUS5940149AAug 17, 1999
Planar polarizer for LCD projectors
MINNESOTA MINING & MFG200 citations99
US4206969AJun 10, 1980
Directional front projection screen
MINNESOTA MINING & MFG62 citations95
US5317349AMay 31, 1994
Overhead projector with achromatic fresnel lens
MINNESOTA MINING & MFG20 citations92
US4900129AFeb 13, 1990
Dual grooved Fresnel lens for overhead projection
MINNESOTA MINING & MFG29 citations92
US4800868AJan 31, 1989
Tilted panel linear echelon solar collector
MINNESOTA MINING & MFG38 citations92
US4436393AMar 13, 1984
Distortion correction for an overhead projector system
MINNESOTA MINING & MFG32 citations92
US4108540AAug 22, 1978
Refractor-reflector radiation concentrator
MINNESOTA MINING & MFG48 citations92
US5504544AApr 2, 1996
Projector with multiple lamp light source
MINNESOTA MINING & MFG47 citations91
US5446594AAug 29, 1995
Catadioptric Fresnel lens
MINNESOTA MINING & MFG14 citations82
US4436392AMar 13, 1984
Distortion correction for an overhead projector system
MINNESOTA MINING & MFG26 citations82
US4385808AMay 31, 1983
Point focus refracting radiation concentrator
MINNESOTA MINING & MFG18 citations82
US5296882AMar 22, 1994
Overhead projector with catadioptric fresnel lens
MINNESOTA MINING & MFG16 citations81
US5453880ASep 26, 1995
Overhead projector with achromatic Fresnel lens
MINNESOTA MINING & MFG13 citations74
US5092672AMar 3, 1992
Condenser lens system for overhead projector
MINNESOTA MINING & MFG17 citations74
US4986651AJan 22, 1991
Overhead projector with centerless Fresnel lens reflective stage
MINNESOTA MINING & MFG13 citations74
US4867555ASep 19, 1989
Retrofocus lens for overhead projector
MINNESOTA MINING & MFG6 citations74
US4741613AMay 3, 1988
Reduced height transmissive overhead projector
MINNESOTA MINING & MFG20 citations74
US4561740ADec 31, 1985
Dual-magnification rear projection lectern
MINNESOTA MINING & MFG8 citations74
US5568324AOct 22, 1996
Overhead projector with catadioptric fresnel lens
MINNESOTA MINING & MFG10 citations72
US4719547AJan 12, 1988
Illumination system for overhead projector
MINNESOTA MINING & MFG3 citations63
US4380374AApr 19, 1983
Variable focal length projection lens for use on overhead projectors
MINNESOTA MINING & MFG6 citations63
USD288571SMar 3, 1987
Rear-projection lectern
MINNESOTA MINING & MFG1 citations52
3M INNOVATIVE PROPERTIES CO
6 patentsUS6179426B1Jan 30, 2001
Integrated front projection system
3M INNOVATIVE PROPERTIES CO182 citations99
US6530664B2Mar 11, 2003
Integrated front projection system with enhanced dry erase screen configuration
3M INNOVATIVE PROPERTIES CO106 citations97
US6394609B1May 28, 2002
Integrated front projection system
3M INNOVATIVE PROPERTIES CO39 citations96
US5995284ANov 30, 1999
Polarized illumination system for LCD projector
3M INNOVATIVE PROPERTIES CO42 citations92
US6024452AFeb 15, 2000
Prismatic light beam homogenizer for projection displays
3M INNOVATIVE PROPERTIES CO16 citations83
US6582084B2Jun 24, 2003
Projector having an inverted head optical arrangement
3M INNOVATIVE PROPERTIES CO0 citations51