Inventor
HELLER HARRY G
GB7 patents
⚠️ This page may combine multiple inventors who share the name “HELLER HARRY G”. Patents are grouped by organization below to help distinguish them — per-person disambiguation is on the roadmap.
PPG INDUSTRIES INC
4 patentsUS5200116AApr 6, 1993
Photochromic chromene compounds
PPG INDUSTRIES INC112 citations94
US4980089ADec 25, 1990
Photochromic spiropyran compounds
PPG INDUSTRIES INC61 citations94
US4931221AJun 5, 1990
Photochromic spiropyran compounds
PPG INDUSTRIES INC103 citations94
US5955520ASep 21, 1999
Photochromic indeno-fused naphthopyrans
PPG INDUSTRIES INC72 citations92