The application of LED in automotive headlights faces many challengesThe biggest obstacle for LED to fully enter the automotive application market isled-headlight

The biggest obstacle for LED to fully enter the automotive application market is the headlights. Traditional light sources for headlights are already very mature, such as representative halogen tungsten lamps. Although the light efficiency is not very high (about 201m/W), the price is low. Although high-pressure xenon lamps are relatively expensive, they are safe, efficient, energy-saving, and have a small size and simple lamp design, making them highly favored.

It is not an easy task for LED to replace traditional light sources in car headlights, and the following issues need to be addressed.

One is brightness output. The brightness requirements for the headlights are: 900lm for the low beam and 1100lm for the high beam, with an overall output of 2000lm, which is approximately the total light source output of 40 1W LuxeonLEDs from Lumileds at 25 ℃. When the ambient temperature rises to 50 ℃, the efficiency of this type of LED will decrease to over 80%. To improve brightness, more LEDs are required, which not only increases costs but also increases the failure rate of LEDs.

The second issue is heat dissipation.

Although traditional light sources generate much higher heat than LEDs, they do not trap high temperatures and reduce their light output.

However, the LED light output will decrease due to an increase in junction temperature. Therefore, heat dissipation is crucial in the design of LED headlights. To prevent LED from overheating and burning out, it is necessary to install heat dissipation fins. Due to the need for many LEDs in the headlights, adding heat sinks can make the volume too large and difficult to incorporate into the lighting fixtures.

The third is optical design, which uses LED as a light source to design lighting fixtures, requiring the transformation of traditional pillar light sources into surface light sources.

To obtain the required lumen output, LEDs require a larger packaging area, which increases the difficulty of optical design. In some current concept cars, modular design replaces the existing single light room design, using multiple sets of light sources to achieve the lighting level of traditional lamps, thereby reducing the difficulty of optical design and increasing the sense of vehicle body shape design.

The application of LED in automotive headlights faces many challenges

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