In the early 1930s, Johnson, a high school science teacher in Michigan, invented an electronic test scoring machine that sensed pencil marks on a standardized form. IBM bought the rights to Reynold's invention and hired him as an engineer to work in their laboratory.
One of Reynold's early assignments was to develop technology that allowed cards marked with pencil marks to be converted into punched cards. That "mark sense" technology was widely used by businesses in the 40s, 50s, and 60s. The Federal Government used it under the name "electrographic" technology.
Johnson was working with Sony on another project when he developed the prototype for a half inch videocassette tape. Lou Stevens noted that Sony was using wider tape on reels. He cut the tape to a half an inch, and put it in a cartridge.
Johnson retired from IBM in 1971. He obtained more than 90 patents through out his life time.