A data projector can cost between twice and 10 times as much as an overhead projector, as of July 2013. Lamp prices likewise exceed those of analog projection equipment, coming in at $300 for a ...

Our school system will be completely changed inside of ten years. ” 1960s: The Overhead Projector. Photo: North Carolina State University. A Brief History: Roger Appeldorn created a machine that ...

On January 15, 1962, Appledorn’s team internally debuted “the first overhead projector with a new Fresnel lens made with a structured-surface plastic.” Because of the plastic lens, the projectors ...

The proposal never got anywhere for a variety of reasons, but politics aside, that’s not exactly your school’s transparency projector. You can check out the spec sheet at Zeiss’s official site .

Teacher William J. Tolley says that education-innovation advocates need to disrupt schools' definitions of success if they are to achieve Sir Ken Robinson's vision for creativity in learning.