Physicist Robert W. Gundlach joined Xerox (then Haloid) in 1952, at the age of 26. He stayed with the company until his retirement in 1995.
During this time, he was credited as an inventor on 155 patents on behalf of Xerox. That works out at around 3.6 patents per year of employment, and indeed he got off to a flying start with three inventions made during his first year of employment subsequently being awarded patents!
Gundlach – who commenced, but never completed, a PhD at the University of Buffalo – is credited with making seminal contributions to the development of practical plain-paper copying technology. Key patents include US Patent No. 2,968,552, Xerographic Apparatus and Method, US Patent No. 3,738,855, Induction Imaging System, and US Patent No. 2,912,586, Xerographic Charging.