How does an overhead projector work.?
Lighting and Projector Sheets The main component of an overhead projector is the base. This base contains a clear glass top with an interior light. A small fan on the back of the unit removes heat that is produced by the light, preventing the overhead projector from overheating. When the light is turned on, the only portion of the base that lets light escape is the glass top; this causes a portion of the light to illuminate the glass as well as anything placed on top of it. Clear plastic projector sheets are placed on the glass with whatever image or text is to be displayed, letting the light shine through the sheet so that it can be projected. Adjustable Arm and Head Attached to the base of the overhead projector is an adjustable arm. The arm is attached to a head unit that contains a mirror. The head unit is generally square or triangular in shape; it features an open bottom and a front side that has a glass lens in it. The mirror within the head unit is positioned in such a way that
