What's Probably In Your Corolla / Prius / C/HR LED Headlamp

[Gerg]

A few weeks ago I came across an almost new, Valeo brand, LED headlamp assembly.  This one was from a BMW, but as it was a Valeo item, it is probably very similar in design to the headlamps that go in a lot of new cars.  When complete in its enclosure there is nothing much to see, really.  So, I did what any person would do, I sawed it in half to have a look.

Beyond all the 'Angel Eyes' BMW bits, you eventually get to the main beam unit, pictured below.  I should add that the two halves of the outer headlamp assembly are very strongly stuck together with mastic/sealant - these inner parts are not serviceable.  You would only see these bits after you had destroyed the outer container.

The main beam unit has five LEDs, three for low beam and two for high beam, I assume.  The large heatsink sits inside of the main headlamp enclosure.

Hopefully you can what-is-doing-what in the photos - these pics were a bit rushed.  The LEDs lie horizontally on their heatsink and shine into the reflector, to be then turned through 90 degrees, shine past the 'beam cutoff mask' and then through the plastic lens.

Nice, innit?

 

[Heidfirst]

Interesting & does show just how different a road legal LED light unit is from a halogen one & hence why you can't just stick an LED bulb into a designed-for-halogen lamp unit & expect to get a road legal result.

[AisinW]

The heat sink is massive, basically the whole reflector units plus the assembly on the headlight is a heat sink.  That's why it last for a very long time by keeping the temperature down.  Multiple small LED chips is more efficient for cooling than put them together next to each other like in aftermarket LED for Halogen replacement. So far, I only find that GTR Ultra 2 has good enough cooling. It uses full heat pipe cooling and only rated to 41 watts, 3900 lumens, and can afford lifetime warranty. However, it is not legal but it looks like original legal light when it is installed on Auris or older model with projector headlight.