Who invented the overhead projector? Unfortunately, various sources do not identify a single person. It has been said that a certain Roger Appledorn was responsible for the technology that was used for the first overhead projector. Appledorn worked in the thermal-fax department of a company and worked on the technology when a top executive discovered what he was doing. Although it was impressive, the company's marketing team did not support Appledorn's idea. Appledorn and his co-researchers decided to market the technology themselves.
Another popular account pointing to the beginning of the overhead projector said that the first overhead projector was used for police identification work. It was said that the first overhead projector used a cellophane roll over a 9-inch stage that allowed facial characteristics to be rolled across the stage.
In 1945, the U.S. Army used overhead projectors for training just as World War II was ending. Then in the late 1950s and early 1960s, overhead projectors began to be used in schools and businesses.
Surfacing in those days was 3M, the company that became the foremost manufacturer of overhead projectors. As demand for overhead projectors increased, another company, Buhl Industries, entered the market and contributed to the technological enhancements of overhead projectors.
