How Do PowerPoint Projectors Work

Multimedia projectors are used to project images onto a screen.

A video projector or multimedia projector takes a video signal, converts it into a viewable image, and projects it on a screen. It can be used to present PowerPoint slide shows, TV and DVDs, video games, and more.

Light Source

A projector shines a powerful white light, usually from a halogen bulb or LED, through a prism. The strength of the light is usually measured in lumens (lm); a dark room needs only 500-1000 lumens but you will need 1500+ lumens for a larger or brighter room.

Producing the Image

The beam of light then passes through a projection technology that converts a video signal into an image able to be projected. Most modern multimedia projectors are one of two kinds: liquid crystal (LCD) and digital light processing (DLP), a proprietary technology. Finally, the image is projected through a lens and onto the screen.

DIY Projectors

Because projectors are often expensive, there is a growing community of hobbyists who build their own, using parts salvaged from broken projectors and other old electronics.

References

• Vivid Light Photography: Multimedia Projectors
• Projector Central: The Great Technology War

Resources

• Boxlight Corporation: DLP vs LCD
• Audiovisualizers: Build Your Own LCD Video Projector
• Lumenlab: State of the Diy Projector (Forum Posting)