Refers to a device that projects images from film or slides onto a screen. Common in contexts like movie theaters, classrooms, and presentations.
映写機でフィルムを映す。
Project the film with a projector.
この映写機は古いが、まだ使える。
This projector is old, but it still works.
slide projector
Compound of 映写 (projection) and 機 (machine). The exact historical derivation is uncertain, but the kanji components clearly indicate a projection device.