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OEM LED headlamps: the past, present and future

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  • #31
    Originally posted by Nuvolari View Post
    Holy cow... each headlight had two massive heatsinks sticking up into the bay for cooling.
    And these are passive heatsinks only right? That is, there are no active fan that forces airflow (perhaps other than when the car is in motion), yes?

    I wonder what the heat soak from the engine is like.
    Jul 2012 ROTM (3-way quad headlight) ; Sep 2015 ROTM (custom muli-lens 7" fogs)

    3-way quad wiring; foreground limiter; squirrel finder;

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    • #32
      Originally posted by Nuvolari View Post
      On the topic of led, today I saw the inside of a BMW M2 engine bay and it had the dual led reflector headlights. Holy cow... each headlight had two massive heatsinks sticking up into the bay for cooling. They looked like the cooling fins you see on some high performance differentials.
      Did you watch todays one take lol?

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      • #33
        Originally posted by rdriggett View Post

        Did you watch todays one take lol?
        Haha I did!
        The Dinan M2

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        • #34
          Originally posted by satrya View Post
          And these are passive heatsinks only right? That is, there are no active fan that forces airflow (perhaps other than when the car is in motion), yes?

          I wonder what the heat soak from the engine is like.
          Don't know if it has fans for active cooling. But the fins point upwards and are uncovered by any plastic and they sit right up front. I'm assuming they get fresh first that travels past it to the engine.

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          • #35
            I believe they are for the angel eyes. These are removable and both contain a single Osram Oslon chip. Would be smart if more lighting manufacturers made removable/serviceable LED modules for low/high beam assemblies. Just like the Ford F150 LED headlamp.

            www.automotiveLEDresearch.com

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            • #36
              Originally posted by evo77 View Post
              Would be smart if more lighting manufacturers made removable/serviceable LED modules for low/high beam assemblies.
              Curious; for OE low/high beams, what is the designed lifespan of the emitters?

              I wonder if making it modular would make the cost proposition less favorable for the manufacturer, given the relatively long expected lifespan and the added cost of number of parts (& the associated assembly steps) for a serviceable bay. With a halogen bulb's expected lifespan, I think it is reasonable to assume that customers / warranty-related coverage would justify a serviceable bay (for bulb replacement). But with LEDs, is it still the case?

              Plus, if good HID projectors with P*32d* base (D2S, etc.) could still be prone to hotspot misalignment even if the alignment tabs seem ok, I wonder how sensitive the LED units that come with smaller reflectors &/ have more of the higher concentrated beams closer to the reflector optics will be, if the design is made modular? I'm not saying it is not impossible from a technical point of view, but I wonder if the cost become unreasonable for the manufacturer.
              Jul 2012 ROTM (3-way quad headlight) ; Sep 2015 ROTM (custom muli-lens 7" fogs)

              3-way quad wiring; foreground limiter; squirrel finder;

              Comment


              • #37
                I think the outer lens would haze before the LED's die.
                Do LED's get dimmer over time?

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                • #38
                  I suppose that with any light source (LED or xenon) placement accuracy is critical to a certain extent within the reflector. And the addition of alignment tabs or mounts helps to ensure that the element is exactly where it should be. Its funny because I have a pair of Mazda CX5 led projectors and for the high beam bucket, one of them is not producing a correct beam pattern. When I disassemble the reflector there are two alignment tabs that fit pretty snug. Meaning there really isn't much "aligning" to do. It goes in only one way. When I inspect both assemblies closely I can see that the LED chip for the bad side is ever so slightly off in relation to the good side. The difference is so miniscule that I'm not even sure that this is the cause of the improper beam pattern. I have not yet further played with it. Just a quick observation.
                  www.automotiveLEDresearch.com

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                  • #39
                    Originally posted by Nuvolari View Post
                    I think the outer lens would haze before the LED's die.

                    Originally posted by evo77 View Post
                    When I inspect both assemblies closely I can see that the LED chip for the bad side is ever so slightly off in relation to the good side. The difference is so miniscule that I'm not even sure that this is the cause of the improper beam pattern. I have not yet further played with it. Just a quick observation.
                    If that is indeed a factor, then it sounds like a production quality control issue. Or does the "bad" side have a different part number; perhaps a deliberate shift in alignment to produce a slightly asymmetrical output?
                    Jul 2012 ROTM (3-way quad headlight) ; Sep 2015 ROTM (custom muli-lens 7" fogs)

                    3-way quad wiring; foreground limiter; squirrel finder;

                    Comment


                    • #40
                      In Automotive LED news...

                      a Chinese company by the name of Lextar revealed their new LED Bi-PES projectors at the 2017 Shanghai International Auto Lamp Exhibit a few days ago. It appears that their trying to enter the OE supplier game to compete with the big dogs like Koito, Stanley, Magneti-Marelli, Valeo and others. I've been trying to find more info but so far here is what they say:

                      Vertically-integrated LED firm Lextar Electronics will showcase an LED PES (poly-ellipsoid system) automotive headlight module at Shanghai International Auto Lamp Exhibition 2017 during March 30 and 31, according to the company.

                      The module is a fisheye headlight combining high and low beams based on in-house-designed optical lenses and can reach maximum luminous intensity of 70,000 cd (candela) and luminance higher than that of a 35W xenon lamp, Lextar said.

                      The lighting source of the module is in-house-produced flip-chip LED chips, Lextar noted. The module complies with ECE R112, the European Union's LED headlight standards specific to headlights with asymmetrical passing beam, and GB25991, China's national standards concerning LED automotive headlights, Lextar indicated.

                      Lextar will also exhibit LED packaging, light bars and lighting engines for use in automotive indoor/outdoor lighting and motorcycle headlights and taillights. These LED lighting modules and devices have passed AEC (Automotive Electronics Council) Q101 and IEC 60810 certification and have service lives of over 30,000 hours, Lextar said.

                      The modules can be customized based on clients' needs, Lextar noted.
                      Source is HERE.



                      www.automotiveLEDresearch.com

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                      • #41
                        Originally posted by evo77 View Post
                        ... will showcase an LED PES (poly-ellipsoid system) ...
                        Interesting.
                        Doesn't current projectors with a wider ellipsoid bowl on top and narrower ellipsoid bowl on the bottom count as poly-ellipsoid as well? Or is this an array of LED surrounded by a bowl that looks like multiple ellipsoids stitched together; similar to stitching together parabolic surfaces (of old-school fresnel reflectors) into the facets of a freeform reflector? I'm curious as to how that gets coupled with the use of a fisheye type lens.
                        Jul 2012 ROTM (3-way quad headlight) ; Sep 2015 ROTM (custom muli-lens 7" fogs)

                        3-way quad wiring; foreground limiter; squirrel finder;

                        Comment


                        • #42
                          I think Lextar wanted to be fancy with their naming convention. PES is the technical term for what we know today as the headlight projector.

                          I haven't been able to find any actual photos of a disassembled projector but if I located the correct patent file below, it shows a VERY unique projector design. See page 8. Can anyone validate what I think I'm seeing?

                          https://patentimages.storage.googlea...106051572A.pdf
                          www.automotiveLEDresearch.com

                          Comment


                          • #43
                            Originally posted by evo77 View Post
                            I think Lextar wanted to be fancy with their naming convention. PES is the technical term for what we know today as the headlight projector. I haven't been able to find any actual photos of a disassembled projector but if I located the correct patent file below, it shows a VERY unique projector design.
                            I see. Figure 1D seem to suggest that they have two ellipsoids merged together left and right a little bit past the centerline. I guess that makes it poly ellipsoid.

                            Originally posted by evo77 View Post
                            See page 8.
                            Are 140 and 130 both emitters? Perhaps 130 is for high beam, and 140 is for low beam?

                            As far as 140 and the reflector 150 and lens 110 is concerned, it looks like an upside-down (and slightly pitched) version of the projector JDMToy is selling:
                            https://store.ijdmtoy.com/LED-Bi-Xen...r-p/35-095.htm


                            I guess the pitch difference allows it to only go through left-right mirroring, but retain the cutoff shadow to block the upper part of the final output?
                            Jul 2012 ROTM (3-way quad headlight) ; Sep 2015 ROTM (custom muli-lens 7" fogs)

                            3-way quad wiring; foreground limiter; squirrel finder;

                            Comment


                            • #44
                              Yes this module has two separate emitters (low and high). 130 is the low beam chip and is forward facing. It doesn't appear to have any reflector. 140 is the high beam chip while 150 is the reflector for it. You'll notice the angle that it pitches which converges to the optical center and then translates to the lens for the beam patterns. 120 is of course the heat sink.


                              [0024] FIG. 1A, the first light source 130 and the second light source 140 are located on both sides of the optical axis 114 of the condenser lens 110, and the first light source 130 and the second light source 140 can be used as a light source of the vehicle lighting device 100. For example, the first light source 130 can be used as a light source of the light, the second light source 140 can be used as the high beam light source.

                              [0025] As for the low-beam light source is a first light source 130, the first light source 130 is disposed in the focal plane of the condenser lens 110 adjacent location 112. Since the first light emitting surface 130 of the first light source 132 is positioned above the optical axis of the condenser lens 110, 114, the first light source 130 and the optical axis of the condenser lens 110 and the boundary 114, by the imaging principle, the light beam emitted from the first light emitting surface 132 may be permeable through the condenser lens 110 is projected upside down and left and right opposite to the light pattern, so that the projected vehicle lamps near bare type 100 having a cutoff line to meet the specifications of the vehicle lighting.


                              www.automotiveLEDresearch.com

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                              • #45
                                Originally posted by evo77 View Post

                                Reflector based LED headlamps have typically shown to be inferior to projector based as far as overall beam performance is concerned. Especially those that have a single source element such as the new Ford F150 and older BMW and Mercedes-Benz models.

                                I have been quite interested though to see how the Explorer LED low beams perform. I will say that I love the color temperature. It's probably closer to 6000K which is higher than the Koito and Stanley LED offerings found on the Japanese imports.

                                If I had to take a guess, the light source in that headlamp is from Osram. Ford and Osram have partnered on other LED projects. It's most likely a Osram Ostar headlamp chip. And according to its color coordinates of Cx: 0.32 Cy: 0.33 that converts to 6000K
                                I used to work for a rental car group. The Explorer has HIDS, it just uses the LED for lobeam and DRL It's not near like say what Acura has or the Escalade, more closer to a halogen in light output. There's a fin on the outside of the light that has the LED in it.
                                Lifes a laughand death is the joke.

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