Overhead Projectors

Overhead Projectors

One of the basic styles of projectors is the overhead projector. It is used to enlarge and display images from transparencies. Although overhead projectors are fairly simple in nature, there are a few points to consider when purchasing one. The first is brightness, which is measured in lumens. Lumens start out at strength of 500 and go up substantially. If you’re planning to use an overhead for a classroom setting, 2,500 lumens is suggested as an adequate strength for most classroom environments using standard transparencies and an average screen size of 60-96 inches. Another part of the equation to keep in mind is focal length. How far back from the screen will the overhead projector be? When determining the focal distance the measurement is taken from the projection lens to the screen. In addition, the larger the projection stage, the base where the transparency is placed, less of a distance is needed in order to project the image. To summarize, it’s a good idea to keep this formula in mind when selecting an overhead projector: focal length x screen width / panel width = throw distance in inches.

Overhead Projector Parts

There are a few basic parts that go into an overhead projector. Knowing these basic parts and how to select and maintain them will ensure continuous use of your projector for a long time. On the whole, there are four major components to the projector, the lamp, the fan, the lens, and the panel. The lamp is usually used in conjunction with a halogen bulb because of its longer use life than other types of bulbs and they are also relatively cheap. The lens, which is fundamental in any style of projector, is located at the top of the machine and comes in different focal lengths, which is measured in millimeters. A fan is needed to keep the machine from overheating due to the excessive amount of heat given off from the bulb, especially if used for long periods of time. For standard overheads a regular glass panel is used as the stage portion that the transparency is placed on.

LCD Panels For Overhead Projectors

Modern overhead projectors differ from standard projectors by including LCD panels. LCD panels are the same type of screen used in most digital electronics such as computers, digital cameras, and PDAs to name a few. The addition of this type of panel to overhead projectors allows the user to project more sophisticated and detailed images. Overhead projectors equipped