Large-format slide projector

A large-format slide projector (also often called large-format projector or large-image projector) is a kind of slide projector for large image projection which has a very powerful light source (up to 12 thousand watts using arc lamps). The light source generates a lot of heat even when filtered to only visible light; the projected transparency is protected from overheating by the heat being distributed across its large area, and cooling fans.

Source: Wikipedia — Large-format slide projector (CC BY-SA 4.0)