Carlson had been frustrated with the slow mimeograph machine and the cost of photography and that lead him to inventing a new way of copying. He invented an electrostatic process that reproduced words on a page in just minutes.
--Carlson was an attorney(a Patent office attorney) and he needed not to just copy words (which often had to be submitted with 3 or more carbon copies) but he also had to copy drawings and diagrams..
Carlson had a hard time finding investors in his new invention. He was turned down by IBM and the U.S. Army Signal Corps, it took him eight years to find an investor, the Haloid Company which later became the Xerox Corporation.
Haloid was a small manufactorer of photographic paper-- in Rochester(NY), with Kodak as a competitor--they were looking for something in the graphic/photographic realm to distingush themself from Kodak.
Chester Carlson was both a research engineer and a patent attorney. He filed a patent application in April, 1939,
and he was smart enough, and knew patent law well enough, that many of Xerox'x patents didn't run out till the 1970's. the first copier wasn't marketed till 1960's or so.. 21 years after the first patent.
the 12 years of 'developement' from the time Haloid first got involved with Carlton till the first copier (The 914 named becase it could copy up to a 9 by 14 inch image) were important years- xerography is semiconductor technology. xerox was 'making copiers', but the copiers were on the very edge of electrical knowledge. transistors and semi conductors were all new, cutting egde technology, Xerox was on the forefront of this technology, and developed many of the bit and pieces that we still use today.. management really failed to recognize what they were doing. they started out as a photography paper company (which is really a chemical industry,) with xerography, the changed into an semiconductor technology company,--but they still saw the 'finished product' (ie, the paper copy) as 'their business' and failed very dramaticly to capitize on all the semiconductor knowledge they had developed along the way.
too bad really.