Inventor · Munich, DE

Udo Weigand

28Patents
8h-index
4Co-inventors
68Inventor score

Filing activity: May 21, 1999 → Jun 5, 2019

Most-cited inventions

PatentTitleAreaCited byStatus
US6146554A Photochromic naphtopyrane colorants, method for the production and use thereof, photochromic object Physics 55 Expired
US6683709B2 Photochromic pyran compounds Chemistry; Metallurgy 29 Expired
US6373615B1 Neutral-colored gray photochromic plastic object Physics 28 Expired
US6315928A Spirofluorenopyrans Physics 21 Expired
US6225466A Photochromic spirofluorenopyran compounds Physics 21 Expired
US6306316A Photochromic plastic object Physics 18 Expired
US6660727B1 Photochromic heterocyclically anellated indenochromene compounds Physics 15 Expired
US6342459B1 Photochromic naphthopyrans Physics 9 Expired
US7459555B2 Photochromic naphthopyrans Physics 8 Expired
US6331625A Photochromic spirofluorenopyran compounds Physics 4 Expired
US6686468B2 H-annellated benzo[f]chromenes Chemistry; Metallurgy 3 Expired
US6881850B2 Heterocyclically annellated indenochromene derivatives Physics 3 Expired
US7229989B2 Blue 3H-naphtho[2,1-b]pyran compounds and use thereof in photochromic articles Chemistry; Metallurgy 2 Expired
US7544315B2 Photochromic h-annellated benzo[f]chromene compounds Physics 2 Active
US6967249B2 Photochromic 3H-naphtho[2,1-b]-pyran compounds and photochromic articles produced therewith Physics 1 Expired
US8933220B2 Photochromic fused naphthopyrans having a benzene ring which is adjacent to the pyran oxygen and is linked to the para substituent via both meta positions Chemistry; Metallurgy 1 Active
US8486312B2 Photochromic naphthopyrans having a double-bridged terphenyl sub-unit Chemistry; Metallurgy 1 Active
US8236716B2 Photochromic benzopyrano-benzopyrans with further fusing Chemistry; Metallurgy 1 Active
US8013174B2 Photochromic spirodihydrophenanthropyrans Chemistry; Metallurgy 0 Active
US7229576B2 Substituted phenanthropyrans Physics 0 Expired
US10647852B2 Photochromic multiple ring-fused naphthopyrans having extreme longwave absorption extending far into the visible wavelength range Physics 0 Active
US7922941B2 Photochromic plastic object Physics 0 Active
US11965102B2 Photochromic annelated naphthopyrane systems with special substituents, for attaining rapid lightening speeds Physics 0 Active
US9963574B2 Photochromic fluorenopyrans with defined dibenzo[B,D]pyrano fused attachment Physics 0 Active
US7892296B2 Photochromic benzopyrans Physics 0 Active

Source: USPTO / EPO open patent data. Inventor disambiguation is heuristic; counts are objective bibliographic measures.