The importance of Overhead Projector in the Language Classroom The idea projecting images has been dated past to ancient times from the dark camera of Ancient Greece. This blog has been created to cover the important aspects of using overhead projector in language classroom as a window across history, function and why it became so important in classroom. The first overhead projector (OHP) was used for police identification is retrieved to Roger Appledorn as it's inventor. In (1945 the USA. ARMY was the first to use it in quantity for training as WORLD WAR II. It began to be widely used in schools and businesses in the late 1950's and early 1960's. For another part, teachers trying to use more modern ways to communicate information and develop understanding that consider overhead projector as their first choice. An overhead projector is a special tool in the classroom. Ideally, it should sit near an outlet and have an extensio...