Head-Up Display

A head up display, or HUD, is a transparent display mounted so that a pilot or other operator can read information from it while still looking forward at the outside world, rather than looking down at an instrument panel, which is where its name comes from. It works by projecting an image from a video generation computer through an optical system, typically a lens or mirror feeding an angled piece of glass called the combiner, which redirects the light into the viewer's eye while collimating it so that the rays are parallel and the eye focuses on it as if it were at infinity, letting the display and the outside scene be seen together in focus. The head up display grew out of the reflector gunsight used on fighter aircraft before the Second World War, and during the early 1940s the United Kingdom's Telecommunications Research Establishment combined a radar display with a gyro gunsight for Royal Air Force night fighters; the specific term head up display is traceable to work done at the Royal Aircraft Establishment in the 1950s for the Blackburn Buccaneer. Originally developed purely for military aviation, the head up display later spread to commercial aircraft, automobiles and other uses, and is regarded as a forerunner of augmented reality technology.