History
The first overhead projector was used for police identification work. It used a cellophane roll over a 9-inch stage allowing facial characteristics to be rolled across the stage. The U.S. Army in 1945 was the first to use it in quantity for training as World War II wound down. It began to be widely used in schools and businesses in the late 1950s and early 1960s.
A major manufacturer of overhead projectors in this early period was the company 3M. As the demand for projectors grew, Buhl Industries was founded in 1953, and became the leading US contributor for several optical refinements for the overhead projector and its projection lens. In 1957, the United States' first Federal Aid to Education program stimulated overhead sales which remained high up to the late 1990s and into the 21st Century.
Read more about this topic: Overhead Projector
Famous quotes containing the word history:
“All history is a record of the power of minorities, and of minorities of one.”
—Ralph Waldo Emerson (1803–1882)
“It takes a great deal of history to produce a little literature.”
—Henry James (1843–1916)
“History is not what you thought. It is what you can remember. All other history defeats itself.
In Beverly Hills ... they don’t throw their garbage away. They make it into television shows.
Idealism is the despot of thought, just as politics is the despot of will.”
—Mikhail Bakunin (1814–1876)