1939 | Edith Weyde "Copyrapid"

https://en.wikipedia.org/wiki/Edith_Weyde

Weyde developed the silver salt Diffusion transfer method—also called "Copyrapid"—which was a process for the accelerated production of a photographic positive image according to an original.^[1][2][6] This led to the development of photocopiers, instant film and instant cameras.