Inventor · Southbridge, MA, US

David A. Krohn

29Patents
10h-index
19Co-inventors
72Inventor score

Filing activity: Apr 24, 1974 → Mar 14, 2000

Most-cited inventions

PatentTitleAreaCited byStatus
US4042405A High strength ophthalmic lens Emerging Cross-Sectional Technologies 84 Expired
US4073579A Ophthalmic lens with locally variable index of refraction and method of making same Chemistry; Metallurgy 79 Expired
US5381504A Optical fiber element having a permanent protective coating with a Shore D hardness value of 65 or more Chemistry; Metallurgy 62 Expired
US3996627A Artificial intraocular lens Emerging Cross-Sectional Technologies 57 Expired
US4277270A Method of manufacture of optical fiber Chemistry; Metallurgy 28 Expired
US4500870A Method and components for remote reading of utility meters Physics 25 Expired
US4012131A High strength ophthalmic lens Emerging Cross-Sectional Technologies 21 Expired
US6593913B1 Method and system for selecting a displayed character using an input device Physics 19 Expired
US4277271A Method of manufacturing graded index optical fibers Chemistry; Metallurgy 13 Expired
US4036624A Heat treatment method for making photochromic gradient lenses Performing Operations; Transporting 10 Expired
US4679029A Optoelectronic rotational position sensor Physics 10 Expired
US3997249A Ion exchangeable segment glass Emerging Cross-Sectional Technologies 9 Expired
US5221308A Low loss infrared transmitting hollow core optical fiber method of manufacture Physics 9 Expired
US4289516A Low loss optical fibers Chemistry; Metallurgy 9 Expired
USRE36146E Optical fiber element having a permanent protective coating with a shore D hardness value of 65 or more General 9 Expired
US4163654A Method of manufacturing graded index optical fibers Emerging Cross-Sectional Technologies 8 Expired
US4606226A Liquid level sensor Physics 8 Expired
US4155734A Preparation of photochromic gradient lenses Performing Operations; Transporting 8 Expired
US4080051A Preparation of photochromic gradient lenses of cosmetically improved color Emerging Cross-Sectional Technologies 7 Expired
US4101302A Photochromic gradient lenses Chemistry; Metallurgy 7 Expired
US3935020A Faraday rotation glasses Chemistry; Metallurgy 7 Expired
US4698616A Optoelectronic rotational position sensor Physics 6 Expired
US4015965A Method of making artificial intraocular lenses with holes Human Necessities 6 Expired
US4028082A Method of making artificial intraocular lenses with holes Chemistry; Metallurgy 6 Expired
US5073027A Fiber optic displacement measuring apparatus Physics 5 Expired

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