Backup camera
Encyclopedia
A backup camera is a special type of video camera
Video camera
A video camera is a camera used for electronic motion picture acquisition, initially developed by the television industry but now common in other applications as well. The earliest video cameras were those of John Logie Baird, based on the electromechanical Nipkow disk and used by the BBC in...

 that is produced specifically for the purpose of being attached to the rear of a vehicle to aid in backing up. Backup cameras are alternatively known as 'reversing cameras' or 'rear view cameras'.

The design of a backup camera is distinct from other cameras in that the image is horizontally flipped so that the output is a mirror image. This is necessary because the camera and the driver face opposite directions, and without it, the camera's right would be on the driver's left and vice versa. A mirrored image makes the orientation of the display consistent with the physical mirrors installed on the vehicle. A backup camera typically sports a wide-angle or fisheye lens
Fisheye lens
In photography, a fisheye lens is a wide-angle lens that takes in a broad, panoramic and hemispherical image. Originally developed for use in meteorology to study cloud formation and called "whole-sky lenses", fisheye lenses quickly became popular in general photography for their unique, distorted...

. While such a lens spoils the camera's ability to see faraway objects, it allows the camera to see an uninterrupted horizontal path from one rear corner to the other. The camera is typically pointed on a downward angle, to view potential obstacles on the ground as well as the position of approaching walls and docks, rather than straight back.

Backup cameras are common on vehicles that tow difficult-to-see trailers, such as motorhome
Motorhome
A motorhome is a type of self-propelled recreational vehicle or RV which offers living accommodation combined with a vehicle engine. The term motorhome is most commonly used in the UK, US, and Canada.-Features:...

s. Recently, with the rise in popularity of in-dash DVD player
DVD player
A DVD player is a device that plays discs produced under both the DVD-Video and DVD-Audio technical standards, two different and incompatible standards. These devices were invented in 1997 and continue to thrive...

s and GPS navigation systems which aid in justifying the expense of adding a color LCD display to the driver's seat, they have become much more common, often available as optional factory accessories on standard passenger trucks and sport utility vehicle
Sport utility vehicle
A sport utility vehicle is a generic marketing term for a vehicle similar to a station wagon, but built on a light-truck chassis. It is usually equipped with four-wheel drive for on- or off-road ability, and with some pretension or ability to be used as an off-road vehicle. Not all four-wheel...

s, as well as aftermarket accessories. Inside the vehicle, the display is typically wired to automatically sense when the transmission is set in reverse, showing the backup view while in reverse, and showing the map (or other content) at all other times.

Variations

Backup cameras are produced in different varieties depending on the application.
  • For large vehicles such as motorhome
    Motorhome
    A motorhome is a type of self-propelled recreational vehicle or RV which offers living accommodation combined with a vehicle engine. The term motorhome is most commonly used in the UK, US, and Canada.-Features:...

    s, camera systems with built-in servomechanism
    Servomechanism
    thumb|right|200px|Industrial servomotorThe grey/green cylinder is the [[Brush |brush-type]] [[DC motor]]. The black section at the bottom contains the [[Epicyclic gearing|planetary]] [[Reduction drive|reduction gear]], and the black object on top of the motor is the optical [[rotary encoder]] for...

    s allow the driver to remotely pan and tilt the camera.
  • Built-in audio intercoms (one-way or two-way) are used in addition to the camera system for communicating with a spotter outside the vehicle - common when backing large trailers or launching boats.
  • Night vision
    Night vision
    Night vision is the ability to see in low light conditions. Whether by biological or technological means, night vision is made possible by a combination of two approaches: sufficient spectral range, and sufficient intensity range...

     cameras use a series of infrared lights for backing in the dark, when the positioning or the intensity of the vehicle's white reverse lights are insufficient for this purpose.
  • Portable or semi-permanent all-in-one camera systems are sold typically for small vehicles that don't have displays permanently installed in the dash. Such systems consist of a small portable screen that hangs from the sun visor above, and a length of wire to reach the cameras.
  • License-plate-frame versions permit permanent installation without any permanent vehicle modifications.
  • Custom cameras are produced to fit specific makes and models of vehicles. For example, for the Hummer H2
    Hummer H2
    The Hummer H2 is an SUV and SUT that was marketed by General Motors under the Hummer brand. It is a large truck , while longer, heavier , and taller with room for six passengers , seven passengers in some models. The rearmost part of the H2 SUV was modified to a pickup truck bed for the 2005 H2 SUT...

    , a specialized camera exists that replaces a factory tail light and matches the original vehicle style. Other custom cameras replace a brake light with a combination device that contains a camera while still illuminating as a brake light.
  • Backup or Reversing Cameras can be added as aftermarket additions to vehicles that do not come with factory-fitted systems. They are available in both wired and wireless versions.
  • Backup or Rear-Camera Displays in the Rearview mirror can be used in vehicles to detect activity behind the car to "avoid the tooling, software, hardware, and testing costs associated with integrating the display/feature in other areas of the vehicle."

External links

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