Overhead projectors are used to project large-size transparencies on a projection screen. Transparencies are imprinted using opaque or translucent inks onto plastic sheets. Transparencies can be generated using pens, ink-jet printers, or through a thermal transfer process from paper originals.

Operation of the overhead projector is very simple:

1. Position the projector in front of the screen. The distance from the projector to the screen will determine the image size.
2. If the projector has a reflector-type head, open the head to expose the mirror. IMPORTANT: Do not operate reflector-type overhead projectors with the head closed!
3. Place the transparency onto the stage glass. Position the transparency so that the top of the transparency is away from the screen, and the image is forward. If you stand on the screen-side of the projector, you should be able to easily read any materials on the transparency directly.
4. Switch on the projector lamp.
5. Adjust the angle of the projection head to position the image on the screen.
6. Adjust the focus knob until the image on the screen is sharp. The focus knob is generally attached to either the projector head or to the extension arm at the back of the projector.

Hints and tips:

• If you have a list of topics on a transparency, and wish to reveal them one at a time, place a sheet of paper over the transparency, covering any material you do not wish to see on the screen.
• NEVER operate a reflector-type overhead projector with the reflector head closed.
• If a lamp blows, many overhead projectors have a lever to select a built-in spare. Turn the projector OFF before sliding the new lamp into position.
• Use the power switch to turn the lamp on and off. Most projectors have thermostatically controlled blowers, which will continue to run after you turn the projector off. Do not unplug the projector until the blower shuts off.
• Avoid bumping the projector when the lamp is hot.

DCAjr - 09/02/1997--HTML 12/29/1999