HG

Helmut Grottrup

Overall (All Time): #1,671,027 of 4,157,543Top 45%
3
Patents All Time

Issued Patents All Time

Showing 1–3 of 3 patents

Patent #TitleCo-InventorsDate
4841128 Circuit unit Thomas Maurer 1989-06-20
4291222 Method and apparatus for card authentication using display of symbols for identification of a personal code word 1981-09-22
4230411 Matrix printer 1980-10-28