The projector has come a long way from the early days when it consisted of an oil lamp and a lens projecting images painted on glass plates. Even the projector of a few decades ago, which used a bright light to project the image from a reel of film, is now outdated. Modern projectors produce optical representations of digitally encoded information with amazing clarity and reliability.

Projectors are now found in classrooms, conference rooms, houses of worship, theaters, sports arenas and homes. There are projectors designed to meet the varied needs...