miscellaneous articles [6]![click to hear](/images/speaker.jpg)
overhead projector ![click to hear](/images/speaker.jpg)
Device that projects the enlarged image of a document printed on a transparency on a screen located behind the user.
optical stage ![click to hear](/images/speaker.jpg)
Glass plate that is lit by an internal light; the document to be projected is placed on it.
optical lens ![click to hear](/images/speaker.jpg)
Transparent optical disk that captures the light from the optical stage and makes it converge toward the mirror.
projection head ![click to hear](/images/speaker.jpg)
Movable part that contains the lens and mirror; a focusing ring changes its position to give a clear image on the screen.
mirror ![click to hear](/images/speaker.jpg)
Polished glass surface that directs light from the lens toward the projection screen.