How Overhead projectors Are Operated

An overhead projector is a device that casts a transparency image on a screen. The process of producing a transparency image is carried out in the following way. First, the OHP ( over head projector) is placed on a table positioned several feet from the screen, and the OHP is plugged into an electrical socket. Then, the transparency is placed face up on a plate of glass surface of OHP, and the switch is turned on. Afterthat, the height of the OHP is adjusted so that the image is centered on screen, and then the focus knob is turned untill the projection image is clear. Finally, the tranparency is replaced with the next tranparency, and step six is repeated.