Carlson receives patent for Xerography

October 6^th 2011

This Day in World History

October 6, 1938

Carlson receives patent for Xerography

Chester Carlson had everything he needed to invent a xerography machine, or photocopier. He had been interested in printing and chemistry since childhood. He perceived a need—in his job, he found that he always needed more copies of documents than he could obtain cheaply. He reasoned that other businesses would also love to have a way of copying documents inexpensively. He had incentive to invent—he had just gotten married and did not think his job offered much chance for getting ahead. Finally, he had an inspiration. Rather than trying to design a copier based on photography, he wanted to explore the field of photoconductivity, in which shining light on a photoconductive surface boosts the electrical conductivity of the surface.

Carlson used his small savings to set up a lab and hire an assistant. They struggled until they developed a working process that involved several steps. Carlson carefully patented his work to protect his interest in it. His efforts to interest companies in his process met with five years of rejection, however. Finally, a nonprofit research firm agreed to develop the process further, taking a share of any resulting royalties. Three years later, in 1947, a company signed a deal to make the first photocopiers. Those machines did not appear until 1959, but they quickly caught on, and the manufacturer—Xerox—enjoyed great success. Carlson himself earned millions from royalties on sales of these machines, huge amounts of which he gave to charity.