After years of technological validation and concept car demonstration, LED car headlamps finally ushered in the promising prospects for mass production vehicles. The landmark event was: Cadillac Escalade Platinum was the new model and became the first in the industry to use the LED car headlamps. The first production model that uses LED as the headlight's near/far beam light source.
Toyota's Lexus LS600h is the world's first production car to use LED headlights, but it only uses LEDs on short-range light, and the remote light source is still halogen. The front lamp assembly with two light sources is supplied by a small car light.
Audi also announced that it will install an LED lighting system as a single light source on the R8 sports car. This will certainly push LED into the momentum of technology in the automotive lighting field.
Obstacles that prevent LED light sources from quickly opening up the automotive market Do the landmark milestones mean that LED headlamps will immediately become an innovative technology that dominates the automotive lighting industry? According to experts predict: Maybe not. Because even if the cost of LEDs can continue to decline at the rate foreseen by Moore's Law, it must be low for a comparable price to HID (high intensity discharge) xenon lamps for many more years; the cost of the LED family should be reduced to Just like a halogen lamp, it takes a long time.
According to Fischer, president of Hella, the size of automotive LEDs currently represents only a small percentage of the market share of light sources, so it is in favor of high-volume models (such as the GM/Chevrolet Malibu model). The matching supply is of great interest. However, LED needs to overcome a series of technical and cost problems to achieve the level of supply as large quantities as Malibu models, and at least a decade away.
Visteon pointed out that the LED's pace of entering the market is indeed slower than originally expected. We predicted in 2004 that LED lights would soon be injected into the city and HID would be eliminated. Obviously, the current situation is not the same, although it is always expected that LED technology can evolve faster than reality. It seems that the high cost is not the only factor that hinders the LED market. There are still challenges in terms of technical performance that need to be overcome. For example, for a single light source, the LED's light intensity is still insufficient. A single point is not bright enough to achieve the following wishful calculations: Reducing the number of LED light sources that make up a combination of luminaires will help to reduce the footprint of automotive luminaires and allow for flexible placement, simplifying the wiring and installation of lighting systems and reducing production costs.
At present, the mainstream status of the LED supply chain is: Hella's LED light source components for the General Motors Cadillac Escalade models are sourced from Osram; while Koito's LEDs use Nichia's light source products, which are matched with Toyota. LS600h models; Philip Lumileds supplies LED light sources to AL (automotive lighting) companies, which in turn configures the lighting system for the Audi R8. According to Koito’s European and American operations manager, we will not be jailed and define the types of light sources and their purchasers, regardless of who they produce (Philips, Osram, or Toyota Gosei). Obviously, the first-tier suppliers of lighting system components try to maintain the flexibility of their own procurement of light source components, and would like to take the opportunity to observe: Which light source device manufacturer's product technology can be the fastest and most cost-effective.
The photoelectric conversion (light energy density) index of today's LED batch products reaches 40 lumens per watt (40lm/W) or more, while the HID lamp is 90lm/W, and the halogen lamp is 201m/W. In addition, according to Hala, the latest LED development prototype has reached 130lm/W. Hella also predicts that in the next 3-5 years, LED light intensity from the same power silicon will increase by 50%. This not only means that LED lamps will be brighter, but also reflects the reduction of energy consumption, thereby improving the vehicle's fuel economy.
It has been estimated that replacing halogen lamps with LEDs can increase the vehicle's mpg (miles per gallon of fuel) index by about 0.25. When it comes to implementing daylight driving regulations in Europe, it is also possible to increase the mpg boost to 0.5. The Lexus model manager pointed out that the application of LED lamps will greatly contribute to improving the fuel economy of the vehicle.
However, LEDs with higher light intensity also emit more heat, and the compact arrangement of the lamps makes the area available for heat dissipation smaller. It is true that low-power LED devices in the semiconductor category generate much less heat than halogen or HID lamps, but most of the latter's heat is generated outside of the fixtures, while LEDs have low power consumption and low heat generation. It is necessary to conduct heat in tiny silicon wafers.
The thermal management of LEDs is a big problem. Even if the smaller heat is concentrated on the chip-sized device to conduct and diverge, the heat capacity of the device can cause a sudden rise in the LED temperature. The operating temperature of the LED must be kept below 150°C. One solution to this heat dissipation problem is to use a larger number of LED light-emitting elements in a luminaire so that the heat output of the individual pieces is smaller, and then disposing them in a large space makes it easy to dissipate heat. This is the technique used by Kosaka’s headlights when it comes to matching the headlights of Toyota’s Lexus LS600h.
Each Cadillac Escalade Platinum headlight consists of seven LED tubes, of which five are used for the short-range beam and the other two are used as the remote source. They all have their own active heat sink—a cooling fan (similar to the small built-in fan in a desktop computer).
According to Hella, thermal management is a particularly troublesome design area for them. Hella focuses on virtual simulation methods to evaluate the optimization of the program selection, and must use enough experimental data to select the simulation tool (simulation software package). The textual research. He pointed out that the challenge to the thermal management problem comes not only from heat conduction, but also from the heat pool device to take out the heat generated by the LED components, but also to solve the ventilation problem, so that heat is emitted from the lighting fixture. If natural ventilation alone is obviously not enough, Hella decided to add a built-in fan to the luminaire.
Valeo's thermal management strategy is a must. It sets a safe working mode for LED lamps, that is, when the lamp temperature rises to a predetermined warning value, it automatically switches to the security mode that reduces the lamp power supply by 20%. It is said that this degree of power supply reduction has little effect on the brightness of the light, but it can significantly suppress the level of heat.
Since the advantages of LED light source vehicles have met all the above-mentioned cost obstacles and layers of technical difficulties, why vehicle manufacturers and their lighting system suppliers still have to insist that Castle Peak does not relax to fully promote the introduction of LED into the market it?
This is due to the fact that this new light source allows unprecedented flexibility in the style design and layout of automotive lamps and is suitable for the individualization of models. Moreover, the LED's light output power density is comparable to that of HID lamps. It is hoped that all existing lighting technologies will be eliminated and the auto lighting market will be dominated.
According to Cadillac Escalade Platinum's model product manager, the LED's luminescence spectrum is close to daylight, which makes the light it emits to be more effective than other light sources for reflection by objects (such as road traffic signs/lines), so that it can be farther away. The distance allows drivers to find out as soon as possible to improve traffic safety. He pointed out that the road signs were almost passively reflected because the LED's light color was close to that of daylight, so that the driver could easily find and see the traffic signs at night as well as during the day.
The operating temperature (absolute color temperature) of LED lights is 5,500-6000 degrees K (1k=1°C), which is whiter than other light sources because the light blue color temperature of the HID lamp is 4000K and the halogen light is 3000K yellow.
Therefore, in the optical design of HID luminaires, the bluest part of the spectrum needs to be shifted to the edge of the spot of the spot where they are fired, because these areas are the places where the driver of the vehicle usually does not pay attention, thereby reducing the color light to the human eye. Uncomfortable interference. However, for oncoming driver drivers, Blu-ray will still cause the driver to dazzle and affect the safety of the vehicle when the vehicle crosses the marginal area. In the aspect of anti-glare interference, LED headlamps have the potential advantages: they can not only protect the driver's comfortable vision, but also not cause visual impairments to the driver of the adjacent/compartment driver. Due to the use of different light sources (LEDs/halogens) for the headlight/remote light of the Toyota Land Cruiser, the owner of the LS600h may be troubled by the apparent color difference of different light sources.
Another great benefit for LED headlamps is that the European Union has passed the DRL regulations that will take effect in 2012, and it has Canadian-recommended regulations that allow daylight to be used as DRLs. ) Different EU regulations require the use of headlamps during the day: As long as the vehicle is in motion, headlights must be turned on, which makes the advantages of low energy consumption and long life of LED light sources even more advantageous.
According to Valeo’s CEO, another potential that has not yet been fulfilled is that LED headlights can use spot arrays to combine the active features of headlights without any need for the current type of devices. Moving parts. Such an active lighting system (for example, an active security function that changes the direction of light irradiation depending on the steering angle) may require the use of a larger number of light pipes than used in the past to form a dot matrix. Valeo is developing a more reliable new adaptive headlamp system based on this idea. Hella Fischer pointed out that this change in the lighting system is also consistent with and reflects the general trend that the mechanical functions of contemporary automobiles are being gradually replaced by the (electronic + electronically controlled + electric) all-electric system. The same set of LED arrays can be used as both headlamp headlights and also for turn signals. They only use their own optical mirror covers when they play different lighting functions.
As a general turn signal, it is only necessary to arrange LED arrays on both sides of the vehicle body, plus a simple switching function. To take advantage of the active security of the intelligent front lighting, so that the front light beam can always illuminate the road in front of the vehicle in synchronization with the turning trajectory of the vehicle, more light source lattices need to be arranged and a more complex light point electricity must be adopted. Control, in accordance with the steering input to control the light and shade combination of the variable spot array and its mirror, so as to synchronously change the direction of the front light beam.
Toyota's Lexus LS600h is the world's first production car to use LED headlights, but it only uses LEDs on short-range light, and the remote light source is still halogen. The front lamp assembly with two light sources is supplied by a small car light.
Audi also announced that it will install an LED lighting system as a single light source on the R8 sports car. This will certainly push LED into the momentum of technology in the automotive lighting field.
Obstacles that prevent LED light sources from quickly opening up the automotive market Do the landmark milestones mean that LED headlamps will immediately become an innovative technology that dominates the automotive lighting industry? According to experts predict: Maybe not. Because even if the cost of LEDs can continue to decline at the rate foreseen by Moore's Law, it must be low for a comparable price to HID (high intensity discharge) xenon lamps for many more years; the cost of the LED family should be reduced to Just like a halogen lamp, it takes a long time.
According to Fischer, president of Hella, the size of automotive LEDs currently represents only a small percentage of the market share of light sources, so it is in favor of high-volume models (such as the GM/Chevrolet Malibu model). The matching supply is of great interest. However, LED needs to overcome a series of technical and cost problems to achieve the level of supply as large quantities as Malibu models, and at least a decade away.
Visteon pointed out that the LED's pace of entering the market is indeed slower than originally expected. We predicted in 2004 that LED lights would soon be injected into the city and HID would be eliminated. Obviously, the current situation is not the same, although it is always expected that LED technology can evolve faster than reality. It seems that the high cost is not the only factor that hinders the LED market. There are still challenges in terms of technical performance that need to be overcome. For example, for a single light source, the LED's light intensity is still insufficient. A single point is not bright enough to achieve the following wishful calculations: Reducing the number of LED light sources that make up a combination of luminaires will help to reduce the footprint of automotive luminaires and allow for flexible placement, simplifying the wiring and installation of lighting systems and reducing production costs.
At present, the mainstream status of the LED supply chain is: Hella's LED light source components for the General Motors Cadillac Escalade models are sourced from Osram; while Koito's LEDs use Nichia's light source products, which are matched with Toyota. LS600h models; Philip Lumileds supplies LED light sources to AL (automotive lighting) companies, which in turn configures the lighting system for the Audi R8. According to Koito’s European and American operations manager, we will not be jailed and define the types of light sources and their purchasers, regardless of who they produce (Philips, Osram, or Toyota Gosei). Obviously, the first-tier suppliers of lighting system components try to maintain the flexibility of their own procurement of light source components, and would like to take the opportunity to observe: Which light source device manufacturer's product technology can be the fastest and most cost-effective.
The photoelectric conversion (light energy density) index of today's LED batch products reaches 40 lumens per watt (40lm/W) or more, while the HID lamp is 90lm/W, and the halogen lamp is 201m/W. In addition, according to Hala, the latest LED development prototype has reached 130lm/W. Hella also predicts that in the next 3-5 years, LED light intensity from the same power silicon will increase by 50%. This not only means that LED lamps will be brighter, but also reflects the reduction of energy consumption, thereby improving the vehicle's fuel economy.
It has been estimated that replacing halogen lamps with LEDs can increase the vehicle's mpg (miles per gallon of fuel) index by about 0.25. When it comes to implementing daylight driving regulations in Europe, it is also possible to increase the mpg boost to 0.5. The Lexus model manager pointed out that the application of LED lamps will greatly contribute to improving the fuel economy of the vehicle.
However, LEDs with higher light intensity also emit more heat, and the compact arrangement of the lamps makes the area available for heat dissipation smaller. It is true that low-power LED devices in the semiconductor category generate much less heat than halogen or HID lamps, but most of the latter's heat is generated outside of the fixtures, while LEDs have low power consumption and low heat generation. It is necessary to conduct heat in tiny silicon wafers.
The thermal management of LEDs is a big problem. Even if the smaller heat is concentrated on the chip-sized device to conduct and diverge, the heat capacity of the device can cause a sudden rise in the LED temperature. The operating temperature of the LED must be kept below 150°C. One solution to this heat dissipation problem is to use a larger number of LED light-emitting elements in a luminaire so that the heat output of the individual pieces is smaller, and then disposing them in a large space makes it easy to dissipate heat. This is the technique used by Kosaka’s headlights when it comes to matching the headlights of Toyota’s Lexus LS600h.
Each Cadillac Escalade Platinum headlight consists of seven LED tubes, of which five are used for the short-range beam and the other two are used as the remote source. They all have their own active heat sink—a cooling fan (similar to the small built-in fan in a desktop computer).
According to Hella, thermal management is a particularly troublesome design area for them. Hella focuses on virtual simulation methods to evaluate the optimization of the program selection, and must use enough experimental data to select the simulation tool (simulation software package). The textual research. He pointed out that the challenge to the thermal management problem comes not only from heat conduction, but also from the heat pool device to take out the heat generated by the LED components, but also to solve the ventilation problem, so that heat is emitted from the lighting fixture. If natural ventilation alone is obviously not enough, Hella decided to add a built-in fan to the luminaire.
Valeo's thermal management strategy is a must. It sets a safe working mode for LED lamps, that is, when the lamp temperature rises to a predetermined warning value, it automatically switches to the security mode that reduces the lamp power supply by 20%. It is said that this degree of power supply reduction has little effect on the brightness of the light, but it can significantly suppress the level of heat.
Since the advantages of LED light source vehicles have met all the above-mentioned cost obstacles and layers of technical difficulties, why vehicle manufacturers and their lighting system suppliers still have to insist that Castle Peak does not relax to fully promote the introduction of LED into the market it?
This is due to the fact that this new light source allows unprecedented flexibility in the style design and layout of automotive lamps and is suitable for the individualization of models. Moreover, the LED's light output power density is comparable to that of HID lamps. It is hoped that all existing lighting technologies will be eliminated and the auto lighting market will be dominated.
According to Cadillac Escalade Platinum's model product manager, the LED's luminescence spectrum is close to daylight, which makes the light it emits to be more effective than other light sources for reflection by objects (such as road traffic signs/lines), so that it can be farther away. The distance allows drivers to find out as soon as possible to improve traffic safety. He pointed out that the road signs were almost passively reflected because the LED's light color was close to that of daylight, so that the driver could easily find and see the traffic signs at night as well as during the day.
The operating temperature (absolute color temperature) of LED lights is 5,500-6000 degrees K (1k=1°C), which is whiter than other light sources because the light blue color temperature of the HID lamp is 4000K and the halogen light is 3000K yellow.
Therefore, in the optical design of HID luminaires, the bluest part of the spectrum needs to be shifted to the edge of the spot of the spot where they are fired, because these areas are the places where the driver of the vehicle usually does not pay attention, thereby reducing the color light to the human eye. Uncomfortable interference. However, for oncoming driver drivers, Blu-ray will still cause the driver to dazzle and affect the safety of the vehicle when the vehicle crosses the marginal area. In the aspect of anti-glare interference, LED headlamps have the potential advantages: they can not only protect the driver's comfortable vision, but also not cause visual impairments to the driver of the adjacent/compartment driver. Due to the use of different light sources (LEDs/halogens) for the headlight/remote light of the Toyota Land Cruiser, the owner of the LS600h may be troubled by the apparent color difference of different light sources.
Another great benefit for LED headlamps is that the European Union has passed the DRL regulations that will take effect in 2012, and it has Canadian-recommended regulations that allow daylight to be used as DRLs. ) Different EU regulations require the use of headlamps during the day: As long as the vehicle is in motion, headlights must be turned on, which makes the advantages of low energy consumption and long life of LED light sources even more advantageous.
According to Valeo’s CEO, another potential that has not yet been fulfilled is that LED headlights can use spot arrays to combine the active features of headlights without any need for the current type of devices. Moving parts. Such an active lighting system (for example, an active security function that changes the direction of light irradiation depending on the steering angle) may require the use of a larger number of light pipes than used in the past to form a dot matrix. Valeo is developing a more reliable new adaptive headlamp system based on this idea. Hella Fischer pointed out that this change in the lighting system is also consistent with and reflects the general trend that the mechanical functions of contemporary automobiles are being gradually replaced by the (electronic + electronically controlled + electric) all-electric system. The same set of LED arrays can be used as both headlamp headlights and also for turn signals. They only use their own optical mirror covers when they play different lighting functions.
As a general turn signal, it is only necessary to arrange LED arrays on both sides of the vehicle body, plus a simple switching function. To take advantage of the active security of the intelligent front lighting, so that the front light beam can always illuminate the road in front of the vehicle in synchronization with the turning trajectory of the vehicle, more light source lattices need to be arranged and a more complex light point electricity must be adopted. Control, in accordance with the steering input to control the light and shade combination of the variable spot array and its mirror, so as to synchronously change the direction of the front light beam.
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