headlights are lights mounted on the front of the vehicle to illuminate the road ahead. While it is common for the term lights to be used interchangeably in informal discussions, headlamp is the term for the device itself, while the lamp refers correctly to the light beam generated and distributed by the device.
Headlamp performance continues to increase throughout the age of the car, fueled by the big difference between daytime and nighttime traffic deaths: The US National Highway Traffic Safety Administration states that nearly half of all traffic-related deaths occur in the dark, even though only 25% cross traveling when darkness.
Other vehicles, such as trains and airplanes, should have headlamps. The bicycle headlights are often used on bicycles, and are required in some jurisdictions. They can be powered by a small mechanically integrated battery or generator into the workings of the bike.
Video Headlamp
Sejarah lampu depan otomotif
Origins
The first horseless carriage uses a train light, which proves unsuitable for traveling at speed.
Mechanics
The earliest headlamps, triggered by acetylene or oil, were operated since the late 1880s. Acetylene lamps are very popular because the flames are resistant to wind and rain. The first electric headlights were introduced in 1898 at Columbia Electric Car from Electric Vehicle Company in Hartford, Connecticut, and optionally. Two factors limit the widespread use of electric headlights: short filament life spans in harsh automotive environments, and the difficulty of generating fairly small dynamo, but strong enough to generate sufficient current.
A number of manufacturers offer acetylene lamps â € Å"Perst-O-Liteâ € as standard equipment for 1904, and Peerless made standard electric headlamps in 1908. A Birmingham company named Pockley Automobile Electric Lighting Syndicate marketed the world's first electric car lamp as a complete set in 1908, consisting of headlights, sidelamps and tail lights and powered by an eight-volt battery.
In 1912, Cadillac integrated the electric ignition and Delco lighting systems of their vehicles, forming a modern vehicle electrical system.
The Guide Lamp Company introduced "dipping" (low-beam) headlamps in 1915, but the Cadillac 1917 system allowed light to be dipped using a lever in the car rather than requiring drivers to stop and exit. The 1924 Bilux Bulb is the first modern unit, has light for both low (dyed) and high (main) beams of headlamp emitting from a single bulb. A similar design was introduced in 1925 by a Guide Lamp called "Duplo". In 1927, switch-operated dipmer or dip switch switches were introduced and became the standard for most of this century. 1933-34 Packards featuring tri-beam headlamps, bulbs that have three filaments. From the highest to the lowest, the blocks are called "across the country", "driving in the country" and "driving in the city". Nash 1934 also uses a three-beam system, although in this case with a conventional two-filament type bulb, and the intermediate ray incorporates a low beam on the driver's side with a high beam on the passenger side, thus maximizing the view. from the roadside while minimizing glare to incoming traffic. The last vehicle with a leg-operated dimmer switch is the Ford F-Series 1991 and the E-Series [Econoline] van. New fog lamps for 1938 Cadillac, and 1954 "Autronic Eye" automatic system of high and low beam selection.
Direct lighting, using switches and electromagnetic reflectors that shift to illuminate the curb only, introduced in the rare, one year 1935 Tatra 77a. The lighting associated with the steering is popularized by the Citroen DS. This makes it possible to turn the lights on the way when the steering turns, and now technology is widely adopted.
A 7-inch (178 mm) sealed headlamp floodlight, one per side, is required for all vehicles sold in the United States from 1940, which significantly freeze illumination technologies that can be used in place until the 1970s for Americans. In 1957 the legislation was amended to allow for a smaller 5.75 inches (146 mm) sealed beam round, two by the side of the vehicle, and in 1974 sealed rectangular beams were also permitted.
Britain, Australia and some other Commonwealth countries, as well as Japan and Sweden, also use 7-inch enclosed blocks extensively, although they are not mandated because they are in the United States. This headlamp format is not widely accepted in continental Europe, which finds the lights replaced and variations in the size and shape of the headlights that are useful in car design. This led to a different front-end design for each side of the Atlantic for decades.
Technology is moving forward worldwide. In 1962 the bulb consortium and European headlamp maker introduced the first halogen lamp for the use of vehicle headlamp, H1. Soon the headlights used a new light source introduced in Europe. This is effectively prohibited in the US, where standard sizes of sealed beam lights are mandatory and low-intensity regulations. US lawmakers face pressure to act, both because of the effectiveness of lighting and for vehicle aerodynamics/fuel savings. High-intensity ridge peaks, limited to 140,000 candela per side of cars in Europe, were limited in the United States to 37,500 candela on each side of the car until 1978, when the limit was raised to 75,000. Increased high-intensity rays to take advantage of higher benefits can not be achieved without moving to halogen technology, and headlights that are sealed with internal halogen burners are available for use on the 1979 model in the United States. In 2010 the halogen-covered beam dominates the closed-beam market, which has dropped sharply since the bullet-replaced bulbs were allowed in 1983.
The High-intensity discharge (HID) system appeared in the early 1990s, first in the BMW 7 Series. 1996's Lincoln Mark VIII was an early American attempt at HIDs, and was the only car with DC HIDs.
Design and style
Beyond the engineering aspects, performance and compliance of the regulation of headlamps, there are considerations of the various ways they are designed and arranged on motor vehicles. The headlights are round for years, because it is the original shape of the parabolic reflector.
Headlamp style outside the United States, pre-1983
There is no requirement in Europe for standard or shape size headlamps, and lamps can be designed in various shapes and sizes, as long as the lamp meets the engineering and performance requirements contained in applicable European safety standards. The rectangular headlights were first used in 1961, developed by CibiÃÆ' © © for CitroÃÆ'¡n Ami 6 and by Hella for the German Ford Taunus. They were banned in the United States where round lights were required until 1975. Another concept of headlamp styling involving conventional round lamps is processed into car bodywork with aerodynamic glass cover, as in Jaguar E-Type 1961, and 1967 VW Beetles.
The headlamp style in the United States, 1940-1983
The design of lights in the US changed little from 1940 to 1983.
In 1940, a consortium of state motorized vehicle operators was standardized on a system of two seven-round (178 mm) spotlights in all vehicles - the only system allowed for 17 years. Four bulb, not two, one high/low and one high-span 5 3 / 4 system (146 mm) beams sealed on each side of the vehicle, introduced in 1957 by Cadillac, Chrysler, DeSoto and Nash on some of their car models in countries that allowed the new system. Other American marques followed when all countries allowed quad lights in 1958. These lights allow for more design flexibility. Automatic stylists such as Virgil Exner undertake design studies with low beams at their conventional outboard locations, and vertical high beams stacked in the midline of the car. No design achieves volume production; most cars have headlamps paired on each side of the car, and some Oldsmobiles have parking lights in the middle of each pair.
Sample settings include the stacking of two headlamps on each side with low beams above the high beam. Nash used this arrangement in the 1957 model. Pontiac used this design starting in the 1963 model; American Motors, Ford, Cadillac, and Chrysler followed two years later. Also in the 1965 model year, the Buick Riviera has a headlights that are hidden. The Mercedes-Benz W100, W108, W111, and W112 models sold in America use this arrangement because their composite home market lights are illegal in the US. British company Alvis and French company Facel Vega also use this arrangement for some of their cars, as Nissan did in Japan.
In the late 1950s and early 1960s, Lincoln, Buick, and Chrysler set the headlights diagonally by placing low floodlights and above high lights. Certain UK cars use a less extreme diagonal setting, with high beam lamps mounted just slightly lower than the low-beam outboard units. Gordon-Keeble 1965, Jensen CV8, Triumph Vitesse, and Bentley S3 Continental use such arrangements.
In 1968 when Federal automated equipment and safety regulations began, the requirements for two large rounds or four rounds of small beams were codified, freezing the headlamp design for years. At the same time, new regulations prohibit decorative or protective elements in front of headlamps every time the headlamps are turned on. Glazed headlights, used on eg. Jaguar E-Type, pre-1968 VW Beetle, 1965 Chrysler and Imperial models, Porsche 356, CitroÃÆ'¡n DS and Ferrari Daytona are no longer allowed and vehicles must be imported with unlocked headlamps for the US market. This change means that vehicles with headlamp configurations designed for good aerodynamic performance can not achieve them for the US market.
When the Federal Motor Vehicle Safety Standard 108 was changed in 1974 to allow a sealed sealing headlight, it was placed in horizontally lined or vertically stacked pairs. In 1979, the majority of new cars in the US market were equipped with rectangular lights. As before with round lights, the US only allows two standard sizes of square-closed blocked beams: A system of two high/low beam units of 2,000 to 142 mm (7.9 by 5.6 inches) corresponding to a 7 inch round format existing, or system of four 165 by 100 mm (6.5 by 3.9 inches) units, two high/low and two high beams. in accordance with the existing 5 3 / 4 in round format (146 mm). International headlamp international style, 1983-present
In 1983, the 1981 petition of Ford Motor Company, the US headlamp regulation was changed to allow for alternating, nonstandard headlamps, with aerodynamic lenses that could for the first time become plastics. This allowed the first US car market since 1939 with a replaceable headlight lamp: Lincoln Mark VII 1984. The composite headlamps are sometimes referred to as "Euro" headlamps, due to the common aerodynamic headlights in Europe. Though conceptually similar to a non-standard European headlamp and replaceable bulb construction, the headlamps are in line with SAE headlamp standards of the US Federal Federal Vehicle Safety Standard 108, and not European safety standards used outside of North America. However, these US regulatory changes largely incorporate headlamp styles inside and outside the North American market.
In the late 1990s, round headlights became popular again in new cars. These are generally not separate standalone bulbs such as those found in older cars (certain Jaguars excluded); they involve circular or oval optical elements in architectural housing assemblies.
Hidden headlights
Hidden headlights (also known as pop-up lights) were introduced in 1936, on Cord 810/812. They are mounted on the front fenders, which are fine until the lights are turned on - each with a small crank mounted on the dashboard - by the operator. They help the aerodynamics when the headlights are not used, and among the typical Cord design features.
Then the recessed headlights require one or more servo and vacuum-operated reservoirs, with associated pipes and linkages, or electric motors, geartrain and connections to raise the lamp to the right position to ensure the correct destination despite ice, snow, and age. Some of the early recessed headlamps, such as those on Saab Sonett III, use a mechanically operated lever connection to raise the headlamps into position.
During the 1960s and 1970s many famous sports cars used this feature such as the Chevrolet Corvette (C3), Ferrari Berlinetta Boxer and Lamborghini Countach as they allow the low bonnet line but raise the lamp to the required height, but since 2003 there is no modern volume which produced model cars using recessed headlamps, as they present difficulty in complying with pedestrian protection requirements added to international automotive safety regulations concerning bumps on the body of the car to minimize injuries to pedestrians being struck by cars.
Some of the hidden headlights themselves do not move, but are covered when not used by panels designed to blend with the car's styling. When the lights are turned on, the cover is removed from the road, usually downward or upward, for example the Jaguar XJ220 1992. The door mechanism can be driven by a vacuum pot, as in some Ford vehicles in the late 1960s to early 1980s such as 1967-1970 Mercury Cougar, or by electric motors such as in various Chrysler products in the mid-1960s through the late 1970s such as the 1967-1967 Dodge Charger.
Maps Headlamp
Rules and conditions
The modern headlamps are electrically operated, positioned in pairs, one or two on each side of the front of the vehicle. The headlamp system is required to produce low and high rays, which can be achieved either by individual lights for each function or by a single multi-function light. High beams (called "main beam" or "full beam" or "beam drive" in some countries) emit most of the light straight ahead, maximizing visibility, but producing too much glare for safe use when other vehicles are present on the road. Because there is no special control of light up, the high beam also causes a backdazzle of fog, rain and snow due to retroreflection of water droplets. Low beams (called "dipped beams" or "passing beams" in some countries) have tighter control over the light up, and direct most of their light down and to the right (in countries with right traffic) or left (in the left-traffic countries), to provide secure visibility forwards without excessive glare or backdazzle.
Low rays
Low rays (dipped rays, passing blocks, meeting beams) the headlights provide a light distribution designed to provide adequate forward and lateral lighting, with light limits directed to the eyes of other road users to control glare. This ray is intended for use whenever another vehicle is present in front, either coming or being taken over.
The international ECE regulations for filament headlamps and high-intensity headlamps define rays with sharp asymmetrical cutoffs that prevent significant amounts of light from entering the eyes of previous or oncoming car drivers. Glare control is less stringent in North American SAE beam standards contained in FMVSS/CMVSS 108.
Highlight
High beam (main beam, driving beam, full beam) headlights provide distribution of bright light, center weighted without special light control directed to the eyes of other road users. Thus, they are only suitable for use when alone on the road, because the glare they produce will fascinate other drivers.
The International ECE Rule allows high-beam lights with a higher intensity than permitted under North American regulations.
Compatibility with traffic directionality
Most low-beam headlamps are specially designed for use on only one side of the road. Front lights for use in countries with left traffic have front headlights with low beams that "slip to the left"; light is distributed with bias down/left to show the driver of the road and the front sign without blinding incoming traffic. The headlights for the country with the right traffic have a low spotlight that "slides to the right", with most of the light directed down/right.
In Europe, when driving a vehicle with traffic lights right in the left-traffic country or otherwise for a limited time (like on vacation or on-the-go), it is a legal requirement to adjust the headlights temporarily so that their fault The ray-side distribution does not fascinate the driver which come. This can be achieved by methods including gluing opaque glass or prismatic lenses to specified lens sections. Some projector type headlamps can be made to produce the right right or left ray by shifting the lever or other moving elements inside or on the lamp unit. Many tungsten (pre-halogen) European code headlamps made in France by CibiÃÆ' ©, Marchal, and Ducellier can be adjusted to produce low left or right beam by using a two position bulb.
Since head-on-the-road headlights hit the driver and did not turn on the driver's way enough, and the embedded blackout and attachment strips reduced the safety performance of the headlamps, some countries required all vehicles to be permanently or permanently registered or permanent semi-bases in the country for equipped with headlights designed for true traffic. North American vehicle owners sometimes personally import and install Japanese market headlights (JDMs) in their cars with the false belief that the performance of the jets will be better, when in fact the misapplication is quite dangerous and illegal.
Use in the afternoon
Some countries require cars to be equipped with daytime running lights (DRL) to improve the uniformity of vehicles moving during daylight hours. Local rules govern how DRL functions can be provided. In Canada, the necessary DRL functions on vehicles manufactured or imported since 1990 may be provided by headlights, fog lamps, flashing headlamps, or by special daytime running lights. Functionally dedicated daytime lights do not involve the required headlamps on all new cars first sold in the EU since February 2011. In addition to the EU and Canada, countries requiring DRLs include Albania, Argentina, Brazil, Bosnia and Herzegovina, Colombia (no later than August/2011), Iceland, Israel, Macedonia, Norway, Moldova, Russia, Serbia, and Uruguay.
Construction, performance, and viewfinder
There are two different emission patterns and standard headlamp construction used in the world: ECE Standards, which are permitted or required in almost all industrialized countries except the United States, and the SAE standards are only compulsory in the US. Japan previously had lighting regulations adjusted to US standards, but for the left side of the road. However, Japan now adheres to ECE standards. The difference between standard SAE and ECE headlamps is mainly in the amount of glare permitted against other drivers on low beams (SAE allows more glare), minimum amount of light required to be thrown straight down the road (SAE requires more), and specific locations within the beam where minimum and maximum light levels are determined.
A low ECE beam is characterized by a horizontal "cutoff" line at the top of the block. Below the bright lines, and above the dark. On the side of the beam facing away from incoming traffic (right in the traffic countries right, left in the left traffic countries), this cutoff sweeps or steps up to direct the light to road signs and pedestrians. Low beam SAE may or may not have a cutoff, and if the cutoff is present, it may be of two different general types: VOL , which is conceptually similar to the ECE rays in that the cutoff is located at the top of the left side of the beam and leads slightly below the horizontal, or VOR , which has a cutoff at the top of the right side of the block and leads to the horizon.
Supporters of each headlamp system condemn the others as inadequate and insecure: US supporters of the SAE system claim that ECE's low-cut beam provides shorter visibility and inadequate lighting for overhead road signs, while international supporters of the ECE system claiming that the SAE system produces too much glare. Comparative studies have repeatedly shown that there is little or no overall safety benefit for either SAE or ECE beams; acceptance and rejection of two systems by various countries is based primarily on systems already in use.
In North America, the design, performance and installation of all automobile lighting devices is governed by the Federal and Canadian Motor Vehicle Safety Standard 108, which combine SAE technical standards. Elsewhere in the world, ECE's international regulations apply either by reference or by incorporation in the respective country's vehicle codes.
U.S. laws require sealed headlamps in all vehicles between 1940 and 1983, and other countries such as Japan, the UK and Australia also use closed blocks extensively. In most other countries, and in the US since 1984, the main headlamps can be alternated.
The headlights should be stored properly (or "aim"). Rules for purposes vary from country to country and from beam specifications to beam specifications. In the US, SAE standard headlamps are addressed regardless of the height of headlamp installation. This provides vehicles with high mounted headlamps that have the advantage of visibility, with the cost of increasing the glare to the driver in lower vehicles. Instead, the ECE headlamp aims at angles connected to the height of mounting the headlamp, to give all vehicles approximately equal distance and all drivers roughly equal to glare.
Bright colors
Headlamps are generally required to produce white light, in accordance with ECE and SAE standards. The current ECE 48 regulations require new vehicles equipped with headlamps that emit white light. Different headlamp technologies produce different types of white light characteristics; the white specifications are quite large and allow clear colors of warm white (with orange-orange-yellow-yellow cast) to cool white (with blue-violet cast). The previous ECE Rules also permitted selective yellow lights, which from 1936 to 1993 were required on all vehicles registered in France. Selective yellow headlamps are no longer common, but are permitted in countries across Europe as well as in non-European locations such as South Korea, Japan and New Zealand. In Iceland, the yellow headlamps are allowed and vehicle regulations in Monaco still formally require selective yellow light from all low lights and beam headlamps, as well as fog lamps if any.
Origin of selective yellow headlights
In France, the law was passed in November 1936, based on suggestions from the Central Commission for Cars and for Traffic in General, a selective yellow light was to be installed. The requirements were initially applied to registered vehicles for road use after April 1937, but were intended to extend to all vehicles through selective yellow light retrofitting on older vehicles, from early 1939. Then the implementation phase was disrupted in September 1939 by the outbreak of war.
Due to an extension of the eligibility requirements for selective yellow lights coming just eight months before the outbreak of war, the popular explanation grew that the French adopted selective yellow lights to allow French soldiers to easily recognize enemy vehicles at night. There are no official documents supporting the military motive for the action. The documented motivation for the adoption of selective yellow lights in France has to do with observations by the French Academy of Sciences dating from 1934. The Academy notes that selective yellow light is less dazzling than white light and that light becomes less widespread when used in fog than a green light or blue.
The yellow selective headlights remain mandatory for cars registered in France until January 1993, when white headlights are authorized for French registered cars, and they quickly become almost universal. However, the yellow selective headlamps remain legal in France, because the current French regulation stipulates that "every motor vehicle must be equipped, at the front, with two or four lights, creating a forward direction of selective yellow or white light enabling efficient lighting of the road at night for distance, in clear condition, from 100 meters ".
Optical system
Reflector light
Optical lens
The light source (filament or arc) is placed at or near the focus of the reflector, which may be a parabola or a non-parabolic complex shape. Fresnel and prism optics are formed into the lens refraction headlamp (shift) part of the light laterally and vertically to provide the required light distribution pattern. Most of the sealed headlamps have optical lenses.
reflective optics
Beginning in the 1980s, the headlamp reflector began to expand beyond a simple caped steel parabola. 1983 The Maestro Austin is the first vehicle equipped with the Lucas-Carello homofocal reflector, which consists of different focal length parabolic sections to improve light collection and distribution efficiency. CAD technology enables the development of reflector headlamps with nonparabolic reflectors, complex shapes. First commercialized by Valeo under their CibiÃÆ' Â © brand, this headlamp will revolutionize car design.
Twin Dodge Monaco/Eagle Premier US market 1987 and European CitroÃÆ'¡n XM is the first car with complex reflector headlamps with multicolored lens optics. The General Motors Guide Lights Division in America had experimented with clear lens-lens reflector lights in the early 1970s and achieved promising results, but the Honda Accord 1990's first American market uses clear-lens multisensor headlights; this was developed by Stanley in Japan.
Optics to distribute light in desired patterns are designed into the reflector itself, rather than to the lens. Depending on the development tools and techniques used, the reflector can be engineered from scratch as a bespoke form, or may start as a stand-alone dish for the size and shape of the completed package. In the latter case, the entire surface area is modified to produce a specially computed special contour segment. The shape of each segment is designed so that their cumulative effects produce the required light distribution patterns.
Modern reflectors are generally made of compression molds or plastic injection molds, although glass and optical metal reflectors also exist. The reflective surface is steam-precipitated aluminum, with clear overcoating to prevent the very thin aluminum from the oxidizers. Very strict tolerance should be maintained in the design and production of complex reflector headlamps.
Dual-beam reflector headlights
Driving at night is difficult and dangerous because of the blinding headlights of traffic coming. Satisfactory headlights illuminate the road ahead without causing the glare to have long been sought. The first solution involves a resistance-type dimming circuit, which lowers the intensity of the headlamps. This produces tilted reflectors, and then becomes a double light bulb with high and low rays.
In the headlamp of two filaments, there is only one filament right at the focal point of the reflector. There are two main ways of producing two different beams of two filament balls in one reflector.
American System
One filament is located at the reflector focal point. The other filaments are shifted axially and radially away from the focal point. In most 2-filament enclosed beams and in bulbs replaced with 2-filament type 9004, 9007, and H13, high beam filaments are in the focal point and the low-beam filaments are out of focus. For use in countries with right traffic, low-beam filaments are positioned slightly upward, forward and to the left of the focal point, so that when the energy, the beam widens and shifts slightly down and to the right of the headlamp axis. Transversa filament lamps such as 9004 can only be used with horizontal filaments, but axial filament bulbs can be rotated or "clocked" by the headlamp designer to optimize the emission pattern or to influence the traffic from the low beam. The latter is achieved by clocking the low-beam filaments in an upward-to-left position to produce the right low-traffic block, or in forward-forward position downward to produce the low left traffic beam.
The opposite tactic has also been used in a certain 2-filament covered beam. Place the low beam filament at the focal point to maximize the collection of light by the reflector, and position the high beam filament slightly backward-down-right from the focal point. The relative shift in direction between two beams is the same as either technique - in the right traffic state, the low rays are slightly down-to-right and the high rays are slightly upward-to the left, relative to each other-but lens optics must be matched by the filament placement selected.
European System
The traditional European method for achieving low and high rays of a single sphere involves two filaments along the reflector axis. High file filaments are at the focal point, whereas low filament filaments are approximately 1 cm in front of the focal point and 3 mm above the axis. Below the low beam filament is a cup shield (called "Graves Shield") that includes a 165 Â ° arc. When the low beam filaments are illuminated, this shield produces a shadow at the bottom of the lower reflector, blocking the ray of light downwards which would otherwise hit the reflector and be cast over the horizon. The bulb is rotated (or "clocked") inside the headlamp to position the Graves Shield thereby allowing the light to attack 15Ã, Â ° the lower half slice of the reflector. This is used to create upsweep or upstep characteristics of low ECE light distribution. The rotative position of the bulb in the reflector depends on the type of emission pattern that will be generated and the traffic direction of the intended market headlamp.
This system was first used with the bulk tungsten bulb Bilux/Duplo R2 in 1954, and then with a 1974 H4 halogen bulb. In 1992, US regulations were changed to allow the use of H4 lamps redesigned HB2 and 9003, and with slightly different production tolerances set. These are physically and electrically exchanged with H4 lamps. Similar optical techniques are used, but with different reflectors or optical lenses to create US rays rather than European ones.
Each system has its advantages and disadvantages. The American system has historically allowed a greater amount of overall light in low light, since all the reflectors and lens regions are used, but at the same time, the American system has traditionally offered fewer controls over the light that causes glare, and for that reason mostly denied outside the US. In addition, the American system makes it difficult to create very different low and high light distributions. High beams are usually a rough copy of a low beam, shifting slightly upward and to the left. European systems traditionally produce low light that contains less overall light, since only 60% of the surface area of ​​the reflector is used to create low light. However, low-light focus and glare control are easier to achieve. In addition, lower 40% of reflectors and lenses are provided for the formation of high rays, which facilitates the optimization of low and high beams.
Developments in the 1990s and 2000s
The complex-reflector technology combined with new bulb designs such as H13 allows the creation of low and high European type rays without the use of the Graves Shield, while the US approval of 1992 over the H4 bulb has traditionally made Europe 60%/40% optical area division for beams low and high common in the US. Therefore, differences in the active optical area and the overall beam light content are no longer always between the US and ECE blocks. Dual-beam HID headlamps using reflector technology have been created using an adaptation of both techniques.
Projector lamp (polyellipsoidal)
In this system the filament rests on one focus of the ellipsoidal reflector and has a condenser lens on the front of the lamp. The shadow lies in the plane of the image, between the reflector and the lens, and the upper edge projection of this shadow provides a low-beam termination. The shape of the shadow edge and its precise position in the optical system determine the shape and sharpness of the cutoff. The shade can be lowered by a solenoid-driven shaft to provide a low beam, and removed from the light path for the high beam. These optics are known as BiXenon or BiHalogen of the projector. If the cutoff image remains in the path of light, a separate high-beam lamp is required. The condenser lens may have little fresnel rings or other surface treatments to reduce cutoff sharpness. The modern condenser lens incorporates optical features specially designed to direct the light upwards to the location of the retroreflective overhead beacon.
Hella introduced ellipsoidal optics for acetylene headlamps in 1911, but after the electrification of vehicle lighting, this optical technique has not been used for decades. The first modern modern polyellipsoidal (projector) automotive lamp is the Super Lite, an additional headlamp produced in a joint venture between Chrysler Corporation and Sylvania and optionally installed in 1969 and 1970 full-sized Dodge cars. It used a transverse 85-watt tungsten-halogen bulb and intended as a center beam, to extend the range of low beams during highway travel when low beams were inadequate but high beams would result in excessive glare.
The projector's main headlamp first appeared in 1981 at Audi Quartz, a Quattro-based concept car designed by Pininfarina for the Geneva Auto Salon. Developed more or less simultaneously in Germany by Hella and Bosch and in France by CibiÃÆ'Â ©, the projector's low beam allowed accurate beam focus and a much smaller-diameter optical package, albeit deeper, for the given beam output. The version of the BMW 7 Series 1986 (E32) sold outside North America is the first production-volume car to use a low beam polyellipsoidal headlamp. The main disadvantage of this type of headlamp is the need to accommodate the physical depth of the assembly, which can extend deep into the engine compartment.
Light source
Tungsten
The first electric headlamp light source is a tungsten filament, which operates in a vacuum or inert-gas atmosphere inside the front bulb or sealed beam. Compared to the light sources of new technology, tungsten filaments emit less light relative to the power they consume. Also, during the normal operation of such lamps, the tungsten boils off the surface of the filament and condenses on the glass bulb, blackening it. This reduces the light output of the filaments and blocks some of the light that will pass through the non-freezing glass bulb, although it blackens less of the problem in a closed beam unit; Its large interior surface area minimizes the thickness of tungsten accumulation. For this reason, all tungsten filaments are plain but obsolete in automotive headlamp service.
Tungsten-halogen
Tungsten-halogen technology (also called "quartz-halogen", "quartz-iodine", "iodine cycle" etc.) Increases effective luminous efficacy of tungsten filaments: when operating at higher filament temperatures resulting in more lumen output per watt input, the halogen-tungsten lamp has a much longer lifetime of light than similar filaments operating without a halogen regeneration cycle. At the same luminosity, halogen bulb also has longer endurance. European halogen headlamp light sources are generally configured to provide more light at the same power consumption as the lowland tungsten of their outputs. In contrast, many US-based designs are configured to reduce or minimize power consumption while maintaining light output above legal minimum requirements; some US tungsten-halogen headlamp light sources produce less initial light than their non-halogen counterparts. The slightly theoretical fuel economy benefit and reducing vehicle construction costs through lower wire and switch ratings is a claimed benefit when the first American industry chose how to apply the tungsten-halogen technology. There is an increase in viewing distance with US halogen blocks, which allowed for the first time to produce 150,000 candela (cd) per vehicle, doubling the non-halogen limit of 75,000 cd but still far from the international European border. 225,000 cd. After replaced halogen lamps were allowed in US headlights in 1983, the development of US lamps continued to support long bulb life and low power consumption, while European design continued to prioritize optical precision and maximum output.
The H1 lamp is the first tungsten-halogen headlamp light source. It was introduced in 1962 by a consortium of European headlamps and headlamps. The bulb has a single axial filament that consumes 55 watts at 12.0 volts, and produces 1550 lumens ± 15% when operated at 13.2 VH2 (55W @ 12.0 V, 1820 lm @ 13.2 V) followed in 1964, and transverse-filament H3 (55 W @ 12.0 V, 1450 lm ± 15%) in 1966. H1 still sees widespread use in low beams, high beams and additional fog and propulsion lights, as does H3. H2 is no longer the current type, as it requires the intricate lampholder interface to the lamp, has a short lifespan and is difficult to handle. For that reason, H2 is withdrawn from Regulation ECE 37 for use in new lamp designs (although H2 lamps are still manufactured for replacement purposes in existing lights), but H1 and H3 remain current and these two lamps were authorized in the United States in 1993. The latest single filament bulb design includes H7 (55W @ 12.0 V, 1500 Ã,  ± 10% @ 13.2 V), H8 (35 WW @ 12.0 V, 800 Ã, Ã,  ± 15% @ 13 , 2 V), H9 (65Ã, W @ 12.0 V, 2100 Ã,Âμm  ± 10% @ 13.2 V), and H11 (55Ã, W @ 12,0 V, 1350 Ã,Âμm  ± 10 % @ 13.2 V). The 24-volt version of many types of bulbs is available for use in trucks, buses, and other commercial and military vehicles.
The first double-filament halogen bulb that produces low and high beam, H4 (60/55 W @ 12 V, 1650/1000 lm Ã, Â ± 15% @ 13.2 V), was released in 1971 and quickly became the main lamp headlamp around the world except in the United States, where H4 is still not legal for automotive use. In 1989, the Americans created their own standard for a light bulb called HB2: almost identical to H4 except with more stringent limits on filament geometry and position variance, and power consumption and light output expressed at a 12.8V AS test voltage.
The first US halogen light bulb, introduced in 1983, is HB1/9004. It is a 12.8-volt transverse design of filaments, which produces 700 lumens on low beams and 1200 lumens on high beams. The 9004 is rated for 65 watts (high beams) and 45 watts (low beams) at 12.8 volts. Other approved US halogen lamps include HB3 (65 W, 12,8 V), HB4 (55 W, 12,8 V), and HB5 (65/55 watt, 12,8 V). All internationally approved and approved bulb of Europe except H4 is currently approved for use in headlamps in accordance with US requirements.
Halogen infrared (HIR) Reflector
Further development of the halogen-tungsten ball has a dichroic layer that passes through visible light and reflects infrared radiation. Glasses in such bulbs may be spherical or tubular. The reflected infrared radiation grabs the filament located at the center of the glass envelope, heating the filament to a greater extent than can be achieved through resistive heating alone. Superheated filaments emit more light without increasing power consumption.
High intensity output (HID)
The high intensity discharge lamp (HID) produces light with an electric arc rather than a luminous filament. The high arc intensity comes from the metal salts that are vaporized inside the arc space. This lamp is officially known as a gas-discharge burner , and has a higher efficacy than a tungsten lamp. Due to an increase in the amount of light available from HID burners relative to halogen lamps, HID headlamps produce a given jet pattern that can be made smaller than a halogen headlamp that produces a comparable emission pattern. Or, larger sizes can be maintained, in which case headlamp xenon can produce stronger emission patterns.
Automotive HID can be called "xenon headlamps", although it is actually a metal halide lamp containing xenon gas. The xenon gas allows the lamp to produce sufficient minimum light immediately upon start, and shorten the run-up time. The use of argon, as is commonly done in streetlights and other metal halide lamp applications, causes the lamp to take several minutes to reach its full output.
The light from the HID headlamps can show a different bluish color when compared to a tungsten-filament headlamp.
Retrofitment
When a halogen headlamp is mounted with a HID bulb, the distribution of light and output is changed. In the United States, vehicle illumination not compatible with FMVSS 108 is not legal. Glare will be produced and approval or certification of headlamp type becomes invalid with the distribution of the changed light, so headlamp is no longer legal in some locale. In the US, suppliers, importers, and vendors offering non-compliance devices are subject to civil penalties. In October 2004, NHTSA had investigated 24 suppliers and all resulted in the termination of the sale or recall.
In Europe and many non-European countries apply the ECE Rule, even HID headlamps designed in such a way should be equipped with a lens cleaner and an automatic self-leveling system, except on a motorcycle. This system usually does not exist on vehicles that were originally not equipped with HID lamps.
History
In 1992 the first production headlight low beam HID was produced by Hella and Bosch starting in 1992 for optional availability on the BMW 7 Series. This first system uses built-in burners, can not be replaced without an anti- UV or touch-sensitive electrical safety piece, the designated D1 - the designation to be recycled a few years later for a completely different type of burner. AC ballast is about the size of a building brick. In 1996 the first American-made effort on HID headlights was on Lincoln Mark VIII 1996-98, which uses reflector headlamps with indivisible burners, integral-ignitor made by Sylvania and specified Type 9500. This is the only operating system on DC, as reliability proved to be lower than that of an AC system. The Type 9500 system was not used in any other model, and was stopped after the Osram takeover of Sylvania in 1997. All HID headlamps around the world today use light bulbs and ballasts operated by AC standards. In 1999 the first worldwide Bi-Xenon HID headlights for low and high light are introduced on the Mercedes-Benz CL-Class.
Operation
Headlamp HID lamps do not run on low-voltage DC currents, so they require ballasts with either internal or external ignitor. The Ignitor is integrated into a light bulb in D1 and D3 systems, and is a separate unit or part of a ballast in D2 and D4 systems. Ballast controls the current to the bulb. The ignition and ballast operations take place in three stages:
- Ignition: high voltage pulses are used to generate an electric arc - in a similar way to spark plugs - that ionize xenon gas, creating conductor channels between tungsten electrodes. Electrical resistance decreases in channel, and current flows between electrodes.
- Initial phase: the bulb is pushed with overload. Because the arc is operated at high power, the temperature in the capsule rises rapidly. The metal salt evaporates, and the arc is intensified and made more spectral. The resistance between the electrodes also falls; the electronic ballast control wheel registers this and automatically switches to continuous operation.
- Sustained operation: all metal salts are in the vapor phase, the arc has reached its stable form, and the radiant efficacy has reached its face value. Ballasts now supply stable electrical power so the bow will not blink. Stable operating voltage is 85 volts AC in D1 and D2 systems, 42 volts AC in D3 and D4 systems. The frequency of alternating square wave is usually 400 hertz or higher.
Burner type
HID headlamp burners produce between 2,800 and 3,500 lumens of between 35 and 38 watts of electrical power, while halogen halogen headlamp lamps produce between 700 and 2,100 lumens of between 40 and 72 watts at 12.8Ã, V.
The current production burner categories are D1S, D1R, D2S, D2R, D3S, D3R, D4S, and D4R. The D stands for debit , and the number is a pointer type. The last letter describes the outer shield. The bow in a headlamp HID bulb produces considerable UV light, but no one escapes the bulb, because a hard UV-absorbing glass shield is incorporated around the bow-bowt tube. It is important to prevent the degradation of UV-sensitive components and materials in the headlights, such as polycarbonate lenses and hard reflector shields. The "S" burners - D1S, D2S, D3S, and D4S - have a plain glass shield and are primarily used in projector type optics. "R" burners - D1R, D2R, D3R, and D4R - are designed for use in optical types of headlamp reflectors. They have an opaque mask that covers a particular part of the shield, which facilitates the optical creation of the brightness/darkness (cutoff) near the top of the low-beam light distribution. Automotive HID burners do emit considerable near-UV light, despite the shield.
Color
The correlated color temperature mounted automotive HID headlights are between 4100K and 5000K while halogen-halogen lamps are 3000K to 3550K. The spectral power distribution (SPD) of the automotive headlamp is disconnected and the spike while the SPD of the filament lamp, like the sun, is a continuous curve. In addition, the color rendering index (CRI) of tungsten-halogen headlamps (98) is much closer than HID (~ 75) headlights to standard sunlight (100). Studies show no significant safety effects of CRI variation levels in headlamps.
Advantages
Enhanced security
Automotive HID lamps offer about 3000 lumens and 90 Mcd/m 2 compared to 1400 lumens and 30 Mcd/m 2 offered by halogen lamps. In optical headlamps designed for use with HID lamps, it produces more usable light. Studies have shown drivers to react faster and more accurately to roadblocks with HID headlights that are better than halogen ones. Hence, good HID headlamps contribute to the safety of driving. The opposite argument is that the glare from the HID headlamps can reduce the safety of traffic by interfering with the vision of other drivers.
Success and output
Luminous efficacy is a measure of how much light is generated versus how much energy is consumed. HID burners provide a higher efficacy than halogen lamps. The highest intensity halogen lamps, H9 and HIR1, produce 2100 to 2530 lumens of about 70 watts at 13.2 volts. A HID D2S burner generates 3200 lumens of about 42 watts during stable operation. Reduced power consumption means less fuel consumption, with fewer CO2 emissions per vehicle equipped with HID lighting (1.3 g/km assuming that 30% of the time the engine is running with the lights on).
Longevity
The average service lifetime of HID lamps is 2000 hours, compared between 450 and 1000 hours for halogen lamps.
Losses
Glare
Vehicles equipped with HID headlamps (except motorcycles) required by ECE 48 regulations must also be equipped with a headlamp lens cleaning system and automatic leveling control. Both of these measures are intended to reduce the tendency of high-output headlamps that cause high levels of glare for other road users. In North America, ECE R48 is not applicable and while lens cleaners and level rectifiers are allowed, they are not required; HID headlights are prominently less common in the US, where they have resulted in significant glare complaints. Scientific studies of headlamp glare have shown that for any given intensity level, the light from the HID headlamps is 40% more striking than the light from the tungsten-halogen headlamps.
Mercury content
HID headlamp bulb types D1R, D1S, D2R, D2S and 9500 contain toxic heavy metal mercury. Disposal of mercury-containing vehicles is increasingly regulated around the world, for example under US EPA regulations. The newer HID bulb designing D3R, D3S, D4R, and D4S produced since 2004 contains no mercury, but is not electrically or physically compatible with headlights designed for previous light bulbs.
Cost
HID headlamps are significantly more expensive to produce, install, purchase, and repair. The additional cost of HID lamps can exceed fuel cost savings through reduced power consumption, although some of these cost losses are offset by longer lifespan of HID burners relative to halogen lamps.
LED
Timeline
The automotive headlamp app using a light-emitting diode (LED) has experienced a very active development since 2004.
In 2006, the first low-beam LED production series was installed at the Lexus LS 600h/LS 600h L plant. High beam and turn signal functions using filament lamps. Headlamp is supplied by Koito.
In 2007 the first headlamp with all the functions provided by LEDs, provided by AL-Automotive Lighting, was introduced in the V10 Audi R8 sports car (except in North America).
In 2009 Hella's headlights at Cadillac Escalade Platinum 2009 became the first all-LED headlights for the North American market.
In 2010 the first all-LED headlamps with adaptive high beams and the so-called Mercedes "Intelligent Light Systems" were introduced on the 2011 Mercedes CLS.
In 2013, the first fully-LED adaptive "Matrix LED" adaptive light introduced was introduced by Audi on the A8 facelifted, with 25 individual LED segments. The system dims the light that will instantly illuminate the approaching vehicle and precedes it, but keeps the full light on the zone between and next to it. This works because the high beam LED is broken down into many light-emitting diodes. High-beam LEDs in both lamps are arranged in matrices and fully adapt electronically to the surroundings in milliseconds. They are enabled and disabled or dimmed individually by the control unit. In addition, the headlights also serve as a cornering lamp. Using predictive route data provided by the MMI plus navigation, the focus of the spotlight shifts in the direction of the bend even before the driver turns the wheel. In 2014: Mercedes-Benz introduces similar technology on the CLS-Class facelifted in 2014, called MULTIBEAM LEDs, with 24 individual segments.
In 2010, LED headlights such as those available on the Toyota Prius provide performance between halogen and HID headlamps, with system power consumption slightly lower than other headlamps, longer lifespan and more flexible design possibilities. As LED technology continues to grow, the performance of LED headlamps is predicted to rise to near, meet, and possibly one day beyond HID headlamps. That happens in mid 2013, when the Mercedes S-Class comes with LED headlamps that deliver higher performance than a comparable HID setup.
Cool lens
Before the LED, all light sources used in headlamps (tungsten, halogen, HID) emit infrared energy that can melt snow and ice from the headlamp lens and prevent further accumulation. LED not. Some LED headlamps move heat from the heat sink on the back of the LED to the inner face of the front lens to warm it, while on the other there is no provision made for melting the lens.
Laser
In 2014 BMW i8 became the first production car to be sold with additional high-beam lights based on laser technology. The limited production of the Audi R8 LMX uses a laser to feature the spotlight, providing lighting for high-speed driving in low light conditions. Rolls-Royce Phantom VIII will use laser lights with a high-emitting range of more than 600 meters.
Automatic headlamp
The automatic system for turning on the headlights has been available since the mid-1960s, initially only on American luxury models such as Cadillac, Lincoln and Imperial. The basic implementation turns on the headlights at dusk and dies at dawn. Modern implementations use sensors to detect the amount of exterior light. UN R48 has required the installation of automatic headlights since July 30, 2016. With Daytime running lights equipped and operated, the dyed headlamp beam will automatically turn on if the car is driving in less than 1,000 lux (automatic switching conditions), such as in the tunnel and at dark environment. while driving in a tunnel or dark environment, daytime running lights will make the glare clearer for future drivers of the vehicle, which in turn will affect the vision of the driver of the impending vehicle, thus, by automatically switching Daytime running lights onto the dipped-beam headlamp , inherent security flaws can be solved and security benefits ensured.
Destination control beam
Headlamp leveling system
The 1948 Citroen 2CV was launched in France with a manual headlamp leveling system, controlled by the driver with a knob through a mechanical stem link. This allows the driver to adjust the vertical goal of the headlamps to offset the passenger and cargo load in the vehicle. In 1954, CibiÃÆ' Â © introduced an automated headlamp buffer system associated with vehicle suspension systems to keep the headlights completely geared off regardless of vehicle load, without driver intervention. The first vehicle to be equipped was Panhard Dyna Z. Beginning in the 1970s, Germany and several other European countries began requiring long distance headlamp spacing systems that allowed the driver to lower the purpose of the lamp by using the dash or button control lever if the rear of the vehicle weighted down with passengers or cargo, which will tend to raise the angle of the lamp's destination and create a glare. Such systems typically use stepper motors in headlamps and rotary switches on dashboards marked "0", "1", "2", "3" for different heights of jets, "0" are "normal" (and highest) positions because when the car loaded lightly.
ECE 48 International Regulations, applicable in most parts of the world outside North America, presently establish a limited range in which the vertical goal of the headlamps must be maintained under various vehicle load conditions; if the vehicle is not equipped with enough adaptive suspension to keep the headlamps properly aligned from the load, a headlamp leveling system is required. Regulations set a tighter version of this anti-glare measure if the vehicle has a headlight with a low-light source (s) that produces more than 2,000 lumens - certain xenon lamps and high power halogens, for example. Such vehicles should be equipped with a self-leveling headlamp system that senses the squat level of the vehicle due to cargo load and the slope of the road, and automatically adjusts the vertical direction of the headlamps to keep the beam properly oriented without the actions required by the driver.
The leveling system is not required by North American regulations. A 2007 study, however, suggests automatic levelers on all headlamps, not just those with high-power light sources, will give the driver greater security benefits from better vision and less glare.
Unidirectional headlights
This provides enhanced lighting for cornering. Some cars have headlights that are connected to the steering mechanism so the lights will follow the front wheel movement. Czechoslovakia Tatra was the earliest implementer of such a technique, producing in 1930s vehicles with a headlamp center direction. American 1948 Tucker Sedan is also equipped with a third center headlamp that is mechanically connected to the steering system.
The 1967 French CitroÃÆ'¡n DS and 1970 CitroÃÆ'¼ng SM are equipped with a complicated dynamic headlamp positioning system that adjusts the horizontal and vertical position of the inlaid headlamps in response to input from the steering and suspension systems of the vehicle.
At that time US regulations require that this system be removed from models sold in the US.
The D series car is fitted with a cabling system that connects the long-range headlamps to the lever on the steering relay while the long-distance headlights on the inside of SM use a sealed hydraulic system using a glycerine-based liquid instead of a mechanical cable. Both of these systems have the same design with the headlamp leveling system of each car. Cables from D system tend to rust on the cable sheath while the SM system gradually releases fluid, causing the remote bulbs to change in, too
Source of the article : Wikipedia
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