miscellaneous articles 
Device that projects the enlarged image of a document printed on a transparency on a screen located behind the user.
Glass plate that is lit by an internal light; the document to be projected is placed on it.
Transparent optical disk that captures the light from the optical stage and makes it converge toward the mirror.
Movable part that contains the lens and mirror; a focusing ring changes its position to give a clear image on the screen.
Polished glass surface that directs light from the lens toward the projection screen.