This unit includes:
Chester Carlson (1906-1968) was the inventor of xerography. After years of independent work, and following unsuccessful attempts to interest several large companies in the invention, he was able to convince the Haloid Company to develop and produce copiers based on his ideas, beginning in 1948. Haloid renamed itself Xerox in 1961, and the rest is history. David Owen's fascinating biography of Carlson, Copies in Seconds [amazon.com] relates the remarkable story of the inventor's life.
This unit was a gift from Andy Stevens, who writes that his father received two of them at a Xerox conference. Andy also sent me a print that he made in 1979 using his kit. Rather than using a photoconducting drum to accumulate the static charge on the dark portions of the image, the kit contains an image printed in conductive paint on clear plastic. It is necessary for all elements of the image to be electrically connected in order to print the image, and the superimposed grid serves the purpose of providing these connections between the letters and numbers of Carlson's original image, which was drawn by Carlson's partner, Otto Kornei, and which records the date (October 22, 1938) and location (Astoria, Queens) of the production of the first successful xerographic print.