μAFS High Resolution ADB/AFS Solution

Grötsch, Stefan G.; Brink, Morten; Fiederling, R.; Liebetrau, Thomas; Mollers, I.; Moisel, Jörg; Oppermann, Hermann; Pfeuffer, Alexander

doi:10.4271/2016-01-1410

Cited by 14 publications

(17 citation statements)

References 4 publications

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“…A promising alternative to discrete LEDs are micropixel LEDs that use chip-on-board technology. An example is the Eviyos LED from Osram, which, despite the significantly lower light emitting surface with an edge length of 115 μm and a LED pixel pitch of 125 μm, emits a luminous flux of about 3 lm per pixel [41]. Currently available patterns with a 32 × 32 array (1024 pixels) theoretically emit a total luminous flux of approximately 3072 lm.…”

Section: Led Array Headlampmentioning

confidence: 99%

High-resolution headlamps – technology analysis and system design

Knöchelmann

Held

Kloppenburg

et al. 2019

Advanced Optical Technologies

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High-resolution vehicle headlamps are the technological way to intelligently illuminate the traffic area to increase safety and comfort. For the technical realization of these headlamps, different technologies come into question, which are the subject of intensive research at universities and among the manufacturers. We present an overview of the possible technologies and analyze their potential for use in high-resolution headlamps. Furthermore, we explain how the design of the optical system for the different technologies can be made. Another part of this paper is the comparison of published prototypes of high-resolution headlamps and the compilation of key properties.

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Section: Led Array Headlampmentioning

confidence: 99%

High-resolution headlamps – technology analysis and system design

Knöchelmann

Held

Kloppenburg

et al. 2019

Advanced Optical Technologies

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“…Although the dark spaces still existed even with the pixel distance of 10 μm, as shown in Figure 7d, the emission image for 10 μm distance yielded limited dark space between pixels, as shown in Figure 7a, and the projection lens in headlight system can reduce the dark space between pixels. [4] Nevertheless, the pixel distance should decrease further by reducing the isolation gap between pixels, followed by complete removal of the dark space.…”

Section: Resultsmentioning

confidence: 99%

“…Micro‐LED (µ‐LED) arrays have attracted great attention because of their wide applications in self‐emissive micro‐displays, multisite photo‐stimulation of nerve cells, and biological neural networks . Individually controllable µ‐LED arrays have recently been implemented to achieve a high‐resolution adaptive driving beam (ADB) or advanced forward lighting system (AFS) for headlights of vehicles, which have 64 µ‐LED pixels per 1 mm 2 , a pixel area of 115 × 115 µm 2 , and pixel pitch of 125 µm in both directions . In order to realize high‐brightness InGaN based individually addressable µ‐LED arrays for the high‐resolution ADB/AFS application, the luminous flux as well as thermal dissipation of the µ‐LED arrays should be further improved.…”

Section: Introductionmentioning

confidence: 99%

“…[1][2][3] Individually controllable m-LED arrays have recently been implemented to achieve a high-resolution adaptive driving beam (ADB) or advanced forward lighting system (AFS) for headlights of vehicles, which have 64 m-LED pixels per 1 mm 2 , a pixel area of 115 Â 115 mm 2 , and pixel pitch of 125 mm in both directions. [4] In order to realize high-brightness InGaN based individually addressable m-LED arrays for the high-resolution ADB/AFS application, the luminous flux as well as thermal dissipation of the m-LED arrays should be further improved. However, there are little report on the improvement of output power of the m-LED arrays for the high-resolution ADB/AFS application.…”

Section: Introductionmentioning

confidence: 99%

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Improved Light Output Power of 16 × 16 Pixelated Micro‐LEDs for Headlights by Enhancing the Reflectivity and Coverage of the p‐Electrode

Kim

Cho

Lee

et al. 2018

Physica Status Solidi (a)

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A pixel array of micro‐light emitting diodes (µ‐LEDs) based on a flip‐chip structure and driven by a passive matrix is fabricated. The array is fabricated through multi‐level metallization using a photosensitive polyimide (PSPI) inter‐metal dielectric (IMD) layer. The device consisted of 256 pixels in a 2 × 2 mm2 array (the individual pixel area is 115 × 115 µm2). This device facilitates the control of individual µ‐LEDs in the array. To investigate the effect of reflectivity and coverage to p‐GaN on mesa area of p‐type electrode, controlled and uncontrolled µ‐LED arrays is fabricated with different reflectivity and coverage of the p‐type electrode. The results show that the devices has similar electrical properties. The light output power and maximum electroluminescence intensity of the controlled µ‐LED array is improved by 3.7 and 5.1 times at injection currents of 100 and 60 mA compared to the uncontrolled µ‐LED array, respectively. The variation of dark spaces in several emission images (total 9 pixels) is investigated as a function of the pixel pitch for the controlled µ‐LED array at an injection current of 20 mA. The results shows that the dark space between pixels almost disappears at a pixel pitch of 125 µm.

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“…Each of the square LEDs has an edge length of 115 µm with a pixel pitch of 125 µm and emits up to 3 lm. 8 Overall, the active luminous area is 4 x 4 mm² with an aspect ratio of 1:1.…”

Section: Led Arraysmentioning

confidence: 99%

Micro pixel LEDs: design challenge and implementation for high-resolution headlamps

Held

Kloppenburg

Lachmayer

2019

Light-Emitting Devices, Materials, and Applications

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High-resolution vehicle headlamps represent a future-oriented technology that can be used to increase traffic safety and driving comfort. Typically, selective absorbing of light using a spatial modulator like DMD, LCD or LCoS creates the light distribution of such headlamp systems. A similar effect can be generated by using LED arrays. Its additive principle generates light only in specific segments if necessary. In general, these arrays can be distinguished between conventional LEDs arranged in an array and micro pixel LEDs. Conventional LED arrays characterize by the design (THT or SMD) with typically a few millimeters edge length. In contrast, a micro-pixel LED uses COB technology, in which individual LED dies are packed in a single housing directly next to each other at a distance of a few microns. By increasing the array resolution, the challenges in designing an optical system for high-resolution headlamps rise. High efficiencies and contrasts call for small, accurate lens geometries and negligibly scattered light effects. Due to limited installation space and manufacturing tolerances, compromises have to be made. Ideally, the optics have to be accurate enough to image each pixel of the micro LED with high contrasts and high efficiency and still be too blurry to project the gaps between each pixel. This results in small distances between LED and optics and therefore in difficult to manufacture radii of curvature. In this paper we specify the challenges to implement micro pixel LEDs in headlamp systems, as well as present the controllability of scattered light effects of these systems.

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μAFS High Resolution ADB/AFS Solution

Cited by 14 publications

References 4 publications

High-resolution headlamps – technology analysis and system design

High-resolution headlamps – technology analysis and system design

Improved Light Output Power of 16 × 16 Pixelated Micro‐LEDs for Headlights by Enhancing the Reflectivity and Coverage of the p‐Electrode

Micro pixel LEDs: design challenge and implementation for high-resolution headlamps

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