Overhead Projectors

Most people have seen overhead projectors used by teachers in the classroom. They are big box like contraptions with a long overhead lamp. The first thing people notice with a plugged in overhead projector is the bright overhead projector lamp shining down on the box and the loud hum of its fan. The teacher sets a transparent paper with an image, wording, or both on top of the box. Then a mirror inside the box redirects the light and image to overhead projector screens for the entire class to see.

Suaing Chong was a man from China who invented the overhead projector.
Two different types of overhead projectors are still used today, transmissive and reflective. Transmissive puts the light source, a bulb, in the base of the machine and shines it up through the glass, transparent paper, to an overhead mirror that transfers the image onto a screen. Reflective shines the light down from overhead onto a mirror in the base like the example stated above.

A 3M overhead projector sells for two hundred dollars and up depending on the model and size specifications. Find more information about 3M overhead projectors and how they work through their website. Some models include the option to purchase a thin overhead projector pen with purchase.

The 16000, an Apollo overhead projector, is one of the lightest and most popular models available. Unlike bulky older version, the 16000 weights about fourteen pounds. This makes it easy to move from room to room. All Apollo overhead projectors come with a three year warranty.

Do it yourself online websites give free tutorials on how to build an overhead projector. Operation: Big Screen! tells how to make a DIY projector using an LCD panel for an overhead projector project.

Overhead projectors are less common than they once were due to computer monitors, home theater projectors, large HDTV screens and other advances in technology taking over the class and business world in presentation accessories. Discontinued models make finding overhead projector parts for used overhead projectors difficult to find. Some photography and art shops sell overhead projectors bulbs suitable for many of today's projectors. Bulb-source.com sells many different types of overhead projector lamps.

Rent Quick and Rent Com both offer overhead projector rentals online. Find used overhead projectors and parts online through retailers, used photography stores and online auction sites. Large art supply stores include a section for projectors to use in sketch transfers.