Back to Future : Evolution of Headlamps

A vehicle without Headlamps ? A vehicle with oil burning lanterns?   Yes, these were all real times that existed “once upon a time.” . But let me first remove the confusion between  term headlamp and headlight before taking journey to past and back to future. By definition a headlamp is a lamp attached to the front of a vehicle to light the road ahead while headlight properly refers to the beam of light produced and distributed by the device. But in common practice both terms are used interchangeably.

Now that we have cleared our doubts about the terms, lets start our journey through time. Our first stop will be 19th century because before that people only used lanterns only.

Headlamps of 19th Century

Horse drawn carriages were the primary mode of transportation before the advent of the automobile. These carriages had lamps with candles and oil burning lanterns. The automobile did not appear until the late 1880s.

Oil lamp
Oil headlamp

At first there was no lighting on a vehicle and no nighttime driving. Although Thomas Edison invented the electric light bulb in 1879, the first lighting on automobiles was not electric headlamps. When people started driving at night, the first vehicle lighting devices were oil (kerosene) burning lanterns.

These lighting devices provided a signal to drivers of other vehicles and carriages, and also to pedestrians. They did not provide any substantial illumination on the road, which was badly needed because the roads were often in poor condition and people were not able to see objects in the road.

1900-1910: The time of experiments

During this time period, vehicles were still using kerosene headlamps and no other lighting devices. These headlamps were in use until 1900. Then the first noticeable improvement in headlamps appeared in the form of carbide (acetylene) headlamps. They replaced Kerosene headlamps and in common use during the decade first decade of 20th century.

acetylene-headlight

The working for acetylene headlamps very simple one. The gas for the acetylene light source was generated by the water dripping slowly onto calcium chloride in a small container. Then gas would come out of nozzle and burn. Light would then be reflected by reflecting plate on the headlamp assembly.

Electric lighting for vehicles started in this decade only but in very limited quantities. But in those days Headlamps were the only application for the generated electricity. AS accumulators and a regulator were complex and expensive. The total installation were almost as expensive as the rest of the car.

At the end of the decade  automotive headlamp with a carbon filament (without gas) and battery started coming as optional equipment on vehicles. Light sources with carbon filaments, osmium filaments, tantalum filaments, tungsten filaments, vacuum bulbs, and finally gas-filled bulbs. Each of these technology steps, were first made for household electric lighting and then modified for use on automotive vehicles a few years later.

The Age of electric headlamps,1911-1920

Peerless made electric headlamps standard in 1908

At the beginning of the decade electric headlamps started coming as standard equipment on some U.S. cars closely followed by European ones. However, the volume was extremely low.  At this time, most headlamps used a 21-candlepower bulb with a shallow parabolic reflector this light source would light a road 50 feet (15 m) wide for the full width of the road from the front of the car to a point over a quarter of a mile away.

In 1915 tungsten filament bulbs filled with nitrogen gas were first used. Adding the inert gas reduced the tungsten evaporation and allowed the filament to last longer. But the lens, or more correctly the cover, did not initially have any optical elements so there was no bending or spreading of the beam pattern.

First regulation about headlight also formed in this decade only.  In 1915, Massachusetts became the first state to require electric headlamps on all motor vehicles. At this same time, tail lights and brake lamps were introduced by automakers on newer car models.

The Glare Reduction

By decade’s end, engineers had premiered a handful of glare-reduction methods for automobile headlamps. One common method was to switch a resistor into the headlamp circuit to reduce the current to the headlamp bulb
filament. Some headlamps were built with reflectors tiltable from the driver’s seat. As another vehicle approached, the reflector would be tilted downward.

The introduction of interior-mount controls was this decade’s most significant development in the history of automotive headlights because it rendered car lighting less primitive and more practical for the end user.

1921-1930- The high-low beam

By the early 1920s, more states had followed Massachusetts’ lead in adopting electric-light requirements on all motor vehicles. The whole point of these laws was to improve the safety of drivers, passengers and pedestrians. In 1921 the IES (Illuminating Engineering Society)  introduced first federal standards. Now It wasn’t enough to merely have electric headlights. But headlights were also now required to beam specific amounts of light, and only in specific directions.

Single high low beam Headlamps
Single high low beam Headlamps

In an effort to better fulfill these requirements, engineers incorporated high and low beam options into headlights. In 1924 cars  used this two-option lighting for the first time. The high-beam filament was placed on the focal point and the low-beam filament was mounted above and to the left. Thus, when switched to the low beam the beam pattern moved down and to the right (side shifting). This arrangement of the filaments continued until the middle 1950s in U.S headlamps.

The sealed beam headlight,1931-40

As the 1930s progressed, the industry launched a slew of lighting innovations, including the replaceable glass lens, the integrated bulb and the metal reflector headlight.

round-sealed-beam-headlamps

The ultimate innovation of the 1930s, however, was the sealed beam headlight. Making its debut in 1936, the sealed beam contained light within a circular enclosure that featured plug prongs in back. With this design, cars could produce light more safely and efficiently than ever. Once a bulb had expired, it could simply be taken into an auto shop and replaced. By decade’s end, the sealed-beam headlight design had become mandatory on all motor vehicles in US.

Cord
1936 cord with hidden headlamps

Also this decade saw Hidden headlamps (also known as pop-up lights). They were introduced in 1936, on the Cord 810/812. They were mounted in the front fenders, which were smooth until the lights were cranked out – each with its own small dash-mounted crank – by the operator. Also aided aerodynamics when the headlamps were not in use, and were among the Cord’s signature design features. But only become popular in 60-70s.

1941-1950 : The turn signal

As the Second World War demanded the attention of the world, car light innovations slowed, yet the auto industry witnessed one closely related development: a flashing light known as the turning signal. In 1940, new cars began rolling out with hand-activated turning signals that would automatically switch off once a turn had been completed.

As the decade advanced, turn signals became a standard feature in all American automobiles. This made it a lot easier to make left turns at four-way intersections, because a driver no longer had to manually signal fellow motorists. .

1951-1960 The different priorities and the twins

Headlamp beam patterns were different in the U.S. and Europe. As U.S. headlamps were 7 inch (178 mm) round sealed beams with high-beam filament on focus, low-beam filament off focus while European headlamps had replaceable bulbs with an internal bulb shield on the low-beam filament.

Lighting engineers, lighting manufacturers, and vehicle manufacturers organized a series of tests to try and develop a common beam pattern. The different priorities for minimizing glare versus maximizing seeing light were the main reasons for the lack of compromise.

This decade also saw the introduction of a twin headlight design . In this design, there were separate  high-beam  and  the low beam headlamp.

The introduction of halogen,1961-1970

The 1960s saw the slow spread of a new type of headlight that would ultimately become universal. In 1962, Italian automakers unveiled the halogen car light. Though basically an incandescent light, the new light used a small trace of bromide or iodine halogen.

Within no time the halogen light became popular throughout Europe due to its brightness and durability. It wasn’t long before halogen bulbs were mandatory in most of Europe. However, the popularity didn’t extend to the U.S., where the tungsten incandescent light remained commonplace.

1971-1980 : US arrival of halogen

During the early 1970s, all U.S. cars featured circular sealed beam headlights that were either dual or separate. At the request of U.S. automakers, who sought more designing liberties, federal highway laws were amended in 1974 to make way for rectangular headlamps.

In the late 1970s, after years of resistance by American automakers, halogen bulbs began flooding into the U.S. Halogen lights swiftly became an industry standard.

The Plastic Lens,1981-1990

The 1980s saw significant regulatory changes that expanded the automotive lighting options for American motorists. Thanks to a policy change by the US National Highway Traffic Safety Administration, drivers now had the choice to choose between sealed beam headlamps and replaceable bulbs alike European counterparts.

The decade also saw the replacement of glass lenses with plastic ones. Plastic offered a stronger barrier against the elements than glass, which could more easily get chipped, cracked or smashed.

1991-2000 : The Xenon

The 1990s marked the debut of two types of lighting that have since gone on to dominate the headlight market. The first of these was the high-intensity discharge (xenon headlights headlight). The other lighting innovation of the 1990s was LED lights, which consist of charged, glowing electrons. As with HIDs, LED lights can last for periods that far exceed the life expectancy of halogen lights.

Furthermore, LED lights emit strong levels of brightness without drawing too heavily on energy supplies. LED tail lights first appeared on automobiles in 1993, but the lighting option didn’t see wider adoption until the following decade. These days, LED lights are the dominant headlight type throughout the automotive industry.

The 21st century

In 2001, the halo headlamp first appeared as a feature of that year’s BMW 5-Series. Halo headlights consist of illuminated rings that light whenever a vehicle is in operation, day or night. Though initially an exclusive hallmark of BMW, the halo headlight has become common in the years since its debut.

The 2010s see the emergence of the laser light. The laser light works by generating concentrated light and turning it white with a lens. While only luxury Audi and BMW models uses the laser light has thus far. It will definitely gain popularity in the coming years as more drivers learn of its power, durability and compact nature.

May light be with you keep reading history of automobiles at the Autolane

 

 

 

 

 

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