A headlamp is a lamp attached to the entrance of a vehicle to illuminate the street forward. Headlamps are additionally usually referred to as headlights, but in the most exact utilization, headlamp is the time period for the system itself and headlight is the term for the beam of light produced and distributed by the system. Headlamp performance has steadily improved all through the car age, spurred by the good disparity between daytime and nighttime visitors fatalities: the US Nationwide Freeway Site visitors Security Administration states that almost half of all visitors-related fatalities occur in the dark, despite only 25% of visitors travelling throughout darkness. Other vehicles, such as 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 first horseless carriages used carriage lamps, which proved unsuitable for EcoLight travel at speed.

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

In 1912 Cadillac integrated their vehicle's Delco electrical ignition and lighting system, forming the trendy vehicle electrical system. The Guide Lamp Company launched "dipping" (low-beam) headlamps in 1915, but the 1917 Cadillac system allowed the sunshine to be dipped using a lever contained in the car reasonably than requiring the driver to cease and get out. The 1924 Bilux bulb was the first trendy unit, having the light for each low (dipped) and EcoLight bulbs high (most important) beams of a headlamp emitting from a single bulb. The same design was launched in 1925 by Information Lamp known as the "Duplo". In 1927 the foot-operated dimmer switch or dip switch was launched and EcoLight grew to become standard for a lot of the century. 1933-1934 Packards featured tri-beam headlamps, the bulbs having three filaments. From highest to lowest, the beams were known as "nation passing", "country driving" and "city driving". The 1934 Nash also used a three-beam system, though on this case with bulbs of the standard two-filament type, and the intermediate beam combined low beam on the driver's side with high beam on the passenger's aspect, so as to maximise the view of the roadside while minimizing glare toward oncoming site visitors.

1952 "Autronic Eye" system automated the number of high and low beams. Directional lighting, utilizing a swap and electromagnetically shifted reflector to illuminate the curbside only, was launched in the uncommon, one-12 months-only 1935 Tatra. Steering-linked lighting was featured on the 1947 Tucker Torpedo's heart-mounted headlight and EcoLight was later popularized by the Citroën DS. This made it doable to turn the light in the direction of journey when the steering wheel turned. The standardized 7-inch (178 mm) spherical sealed-beam headlamp, one per facet, was required for all autos bought within the United States from 1940, EcoLight brand just about freezing usable lighting technology in place until the 1970s for Individuals. In 1957 the legislation changed to allow smaller 5.75-inch (146 mm) round sealed beams, EcoLight two per facet of the car, and in 1974 rectangular sealed beams were permitted as nicely. Britain, Australia, and some other Commonwealth countries, as well as Japan and Sweden, also made in depth use of 7-inch sealed beams, though they weren't mandated as they were in the United States.