An overhead projector is a type of device used to display images or text on a large screen or wall. The projector consists of a light source, a lens system, and a mirror that reflects the image onto a surface.
The projector is placed on a sturdy surface, and the image or text to be projected is placed on a transparent sheet or film, known as a transparency. The transparency is placed on a glass plate, known as the stage, and the light from the projector passes through the transparency and is magnified by the lens system before being reflected onto the screen.
Overhead projectors are commonly used in educational and business settings, where they are used to give presentations, lectures, or training sessions. They can also be used in artistic and creative contexts, such as in the creation of murals or other large-scale artworks.
While overhead projectors have been largely replaced by digital projectors and other newer technologies, they remain a simple and effective tool for visual communication and are still used in some settings.