Projectors

Projectors are display devices that form images by projecting light onto a screen or wall. In digital projectors, light from a lamp, LED, or laser engine is modulated by an imaging system to produce color and brightness. The three most common imaging technologies are digital light processing (DLP), liquid crystal display (LCD), and liquid crystal on silicon (LCoS). DLP uses a chip with micro-mirrors and a color wheel; LCD uses three LCD panels for red, green, and blue; LCoS combines reflective silicon with LCD-like cells.

Light sources determine brightness and life. Lamp-based units use replaceable high-intensity lamps; LED- and laser-based models tend to last longer and have different color characteristics. Brightness is rated in ANSI lumens; typical home theater projectors range from about 1000 to 3000 lumens, while business models exceed that. Resolution ranges from SVGA to 4K, with HDR supported by many modern units.

Throw distance and lenses determine image size. Short-throw and ultra-short-throw designs enable large images in small rooms. Common inputs include HDMI, VGA, USB, and DisplayPort; some models offer wireless casting. Features such as keystone correction and lens shift assist alignment.

Applications include home cinema, classrooms, business presentations, and events. Maintenance may involve cleaning air filters and replacing lamps or light engines. The choice of projector depends on room lighting, screen quality, seating distance, and budget, with trade-offs among image brightness, color accuracy, installation flexibility, and running costs.