Video projector

This article is about home and business projectors; for public exhibition projectors, see digital cinema.
Projected image from a video projector in a home cinema.

A video projector is an image projector that receives a video signal and projects the corresponding image on a projection screen using a lens system. All video projectors use a very bright light to project the image, and most modern ones can correct any curves, blurriness, and other inconsistencies through manual settings. Video projectors are widely used for many applications such as conference room presentations, classroom training, home theatre and concerts. Projectors are widely used in many schools and other educational settings,[1] sometimes connected to an interactive whiteboard to interactively teach pupils.


A video projector, also known as a digital projector, may project onto a traditional reflective projection screen, or it may be built into a cabinet with a translucent rear-projection screen to form a single unified display device.

Common display resolutions for contemporary (as of 2012) portable projectors include SVGA (800×600 pixels), XGA (1024×768 pixels), 720p (1280×720 pixels), and 1080p (1920×1080 pixels).

The cost of a device is determined by its resolution and its light output. A projector with a higher light output (measured in lumens, “lm”) is required for a larger screen or for a room with a larger amount of ambient light.[2] For example, a light output of approximately 1500 to 2500 ANSI lumens is suitable for small screens viewed in rooms with low ambient light; approximately 2500 to 4000 lm is suitable for medium-sized screens with some ambient light; over 4000 lm is needed for very large screens or for use in rooms with no lighting control such as conference rooms.

A few camcorders have a built-in projector suitable to make a small projection; a few more powerful "pico projectors" are pocket-sized, and many projectors are portable.

Projection technologies

A Zenith 1200 CRT Projector based home theater, ca. 2006.

Obsolete technologies

Do-it-yourself video projectors

Some hobbyists take a do-it-yourself (DIY) for low cost. They build their own projectors from kits, sourced components, or from scratch. Through the internet, they obtain plans to construct them [4] for domestic and classroom use. The DIY-projectors are now being used both in developed countries and in developing countries in the interest of providing education as well as for entertainment purposes.

See also


  1. Charles Proctor (January 18, 2007). "Christmas is a time for taking -- from schools". Los Angeles Times. Retrieved 2010-11-26.
  2. Richard Cadena (2006). Automated Lighting: The Art and Science of Moving Light in Theatre, Live Performance, Broadcast, and Entertainment. Focal Press. p. 344. ISBN 978-0-240-80703-4.
  3. Kaczorowski, A., Gordon, G.S.D., Palani, A., Czerniawski, S. and Wilkinson, T.D. (2015) “Optimization-Based Adaptive Optical Correction for Holographic Projectors”, IEEE/OSA Journal of Display Technology, 11 (7).
  4. Frank Völkel (November 13, 2004). "Supersize Your TV for $300: Build Your Own XGA Projector!". Tom's Hardware. Retrieved 2010-11-26.
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