A headlamp is a lamp attached to the front of a car to illuminate the road forward. Headlamps are additionally usually known as headlights, but in the most exact usage, headlamp is the term for the gadget itself and headlight is the term for the beam of gentle produced and distributed by the gadget. Headlamp performance has steadily improved all through the vehicle age, spurred by the nice disparity between daytime and nighttime site visitors fatalities: the US Nationwide Highway Traffic Security Administration states that nearly half of all visitors-related fatalities occur at the hours of darkness, regardless of only 25% of visitors travelling throughout darkness. Different autos, similar to trains and aircraft, are required to have headlamps. Bicycle headlamps are often used on bicycles, and are required in some jurisdictions. They are often powered by a battery or a small generator like a bottle or hub dynamo. The primary horseless carriages used carriage lamps, which proved unsuitable for travel at pace.

The earliest lights used candles as the most typical kind of gasoline. The earliest headlamps, EcoLight dimmable fuelled by combustible gasoline such as acetylene gasoline or oil, EcoLight dimmable operated from the late 1880s. Acetylene gasoline lamps were widespread in 1900s as a result of the flame is resistant to wind and EcoLight dimmable rain. Thick concave mirrors mixed with magnifying lenses projected the acetylene flame light. Quite a lot of automobile manufacturers supplied Prest-O-Lite calcium carbide acetylene fuel generator cylinder with gasoline feed pipes for lights as commonplace gear for 1904 cars. The first electric headlamps were launched in 1898 on the Columbia Electric Car from the Electric Car Firm of Hartford, Connecticut, EcoLight and had been non-compulsory. Two factors limited the widespread use of electric headlamps: the short life of filaments in the cruel automotive setting, and EcoLight dimmable the issue of producing dynamos small sufficient, but powerful enough to produce enough present. Peerless made electric headlamps commonplace in 1908. A Birmingham, England firm known as Pockley Vehicle Electric Lighting Syndicate marketed the world's first electric automotive-lights as a complete set in 1908, which consisted of headlamps, EcoLight dimmable sidelamps, EcoLight dimmable and tail lights that have been powered by an eight-volt battery.

In 1912 Cadillac built-in their car's Delco electrical ignition and lighting system, forming the fashionable car electrical system. The Guide Lamp Company launched "dipping" (low-beam) headlamps in 1915, however the 1917 Cadillac system allowed the sunshine to be dipped using a lever inside the automotive reasonably than requiring the driver to cease and get out. The 1924 Bilux bulb was the primary modern unit, having the sunshine for both low (dipped) and excessive (major) beams of a headlamp emitting from a single bulb. An identical design was introduced in 1925 by Guide Lamp known as the "Duplo". In 1927 the foot-operated dimmer switch or dip change was launched and grew to become customary for much of the century. 1933-1934 Packards featured tri-beam headlamps, the bulbs having three filaments. From highest to lowest, the beams were referred to as "nation passing", "nation driving" and "city driving". The 1934 Nash additionally used a three-beam system, although on this case with bulbs of the typical two-filament sort, and the intermediate beam mixed low beam on the driver's side with excessive beam on the passenger's aspect, so as to maximise the view of the roadside while minimizing glare toward oncoming visitors.

1952 "Autronic Eye" system automated the choice of excessive and low beams. Directional lighting, using a swap and electromagnetically shifted reflector to illuminate the curbside only, was introduced in the rare, one-year-only 1935 Tatra. Steering-linked lighting was featured on the 1947 Tucker Torpedo's middle-mounted headlight and was later popularized by the Citroën DS. This made it doable to show the sunshine in the path of journey when the steering wheel turned. The standardized 7-inch (178 mm) round sealed-beam headlamp, one per facet, was required for dimmable LED bulbs all automobiles offered in the United States from 1940, nearly freezing usable lighting technology in place until the 1970s for EcoLight lighting Americans. In 1957 the regulation modified to permit smaller 5.75-inch (146 mm) round sealed beams, two per side of the car, and in 1974 rectangular sealed beams were permitted as well. Britain, Australia, EcoLight solar bulbs and another Commonwealth international locations, in addition to Japan and EcoLight home lighting Sweden, also made intensive use of 7-inch sealed beams, although they weren't mandated as they have been in the United States.