data projector

A device that projects computer output onto a white or silver fabric screen that is wall, ceiling or tripod mounted. It is widely used in classrooms and auditoriums for instruction and slide presentations.

A data projector has a VGA socket for computer screen input at resolutions such as 800x600, 1024x768 and 1280x1024. Many units also support TV with a composite video input for a VCR, DVD or cable box. Some projectors support all the analog and digital TV interfaces and are used for home theater projection (see front-projection TV).

Increasingly Smaller and Lighter

In the 1980s, the first data projectors weighed more than 40 pounds, using a single cathode ray tube (CRT) to project a monochrome image. When color units came out, they weighed even more because of their three CRTs (red, green and blue). CRT projection systems have mostly given way to smaller, more convenient technologies, although they still offer the highest quality.

In the 1990s, projectors became transparent LCD panels, but although significantly lighter than CRTs, they required an overhead projector for illumination (see LCD panel). By the turn of the century, projectors shrank to only a few pounds (see microdisplay), and within a few years to only a few ounces (see microprojector). See extended desktop mode, front-projection TV and rear-projection TV.

The Good Old Days

Starting in 1980, Alan Freedman, editor of this encyclopedia, used to lug a monochrome data projector to his computer literacy classes in order to show examples to non-technical managers. Projector, computer equipment and rolling cases together weighed more than one hundred pounds.

Twenty Years Later

In 2000, using Texas Instrument's DLP technology, Compaq introduced the MP1400 at slightly more than four pounds, one of the first lightweight data projectors. See microprojector. (Image courtesy of Compaq Computer Corporation.)

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data projector	Portable Data Projector