magic lantern; slide projector
Refers to an early image projector, historically a magic lantern, and by extension a modern slide projector. The term is somewhat dated; スライドプロジェクター is more common for modern devices.
See also: スライドプロジェクター
We projected old photos onto the wall with a magic lantern.
This magic lantern was used in the Meiji period.
Compound of 幻灯 (magic lantern, from 幻 'phantom' + 灯 'lamp') and 機 'machine'. The exact historical derivation is uncertain; the term likely emerged in the late 19th or early 20th century.