An overhead projector is a very basic but reliable form of projector. The overhead projector displays images onto a screen or wall. It consists of a large box containing a cooling fan and an extremely bright light, with a long arm extended above it. At the end of the arm is a mirror that catches and redirects the light towards the screen. An overhead projector can be used to enlarge images onto the screen or wall for audiences to view. Transparencies can be placed onto the projector to be viewed by both the audience and the speaker. The overhead projector was once a common feature in both classrooms and business meetings. Recently, it has seen a decline in use, as more sophisticated computer based projectors are favored. The overhead projector was first seen during World War II. It was used as a tool to train large numbers of servicemen. In the 1950s and 60s, it crossed over into the classroom as an educational tool, and then into the business world as a training tool. The overhead projector reached its sales peak in the 1990s, when almost every classroom and business place in America had one installed.
Brief History of Overhead Projector
Overhead projectors continue to be used for presentation purposes in both school and business settings despite the advancements in presentation technology. Read on to learn the humble history of, who invented and the early uses of the overhead projector. * Overhead Projector - The Early Days
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. * Fast Forward to the 80's
During the 1980s-1990s, overhead projectors continued to be an essential tool for classroom learning. The technology then used a liquid-crystal panel mounted in a plastic frame that was placed on top of the overhead projector and connected to the video output of computers. Overhead projectors used monochrome LCD panels and could only display NTSC video output. Soon after, overhead projectors capable of handling color images took the place of the monochrome models. * Technology Finally Caught on to Overhead Projectors
Today, the use of overhead projectors has finally reached its peak. For advanced countries, other presentation tools are now being used in both classroom and business settings. These presentation tools are more interactive, highly computerized and easier to use. However, in less developed countries where technological advancement has not been fully realized, overhead projectors are still the top choice for business and educational presentations.
The Evolution of Projection Technology
Corporate America was first introduced to projection technology in the 1950s. Although the technology itself has...