scholarly journals Metasurface-based compact light engine for AR headsets

2019 ◽  
Author(s):  
Seyedeh Mahsa Kamali ◽  
Ehsan Arbabi ◽  
Andrei Faraon
Keyword(s):  
Light Engine

Laser-activated remote phosphor light engine for projection applications

2015 ◽  
Author(s):  
Martin Daniels ◽  
Oliver Mehl ◽  
Ulrich Hartwig
Keyword(s):  
Remote Phosphor ◽  
Light Engine

Thermal Performance of a Light Emitting Diode Light Engine for a Multipurpose Automotive Exterior Lighting System With Competing Board Technologies

2017 ◽  
Vol 139 (2) ◽  
Author(s):  
Umut Zeynep Uras ◽  
Mehmet Arık ◽  
Enes Tamdoğan
Keyword(s):  
Thermal Performance ◽  
Computational Models ◽  
Printed Circuit Boards ◽  
Light Emitting Diode ◽  
Ambient Conditions ◽  
Vapor Chamber ◽  
Metal Core ◽  
Light Emitting ◽  
Lighting Systems ◽  
Light Engine

In recent years, light emitting diodes (LEDs) have become an attractive technology for general and automotive illumination systems replacing old-fashioned incandescent and halogen systems. LEDs are preferable for automobile lighting applications due to its numerous advantages such as low power consumption and precise optical control. Although these solid state lighting (SSL) products offer unique advantages, thermal management is one of the main issues due to severe ambient conditions and compact volume. Conventionally, tightly packaged double-sided FR4-based printed circuit boards (PCBs) are utilized for both driver electronic components and LEDs. In fact, this approach will be a leading trend for advanced internet of things applications embedded LED systems in the near future. Therefore, automotive lighting systems are already facing with tight-packaging issues. To evaluate thermal issues, a hybrid study of experimental and computational models is developed to determine the local temperature distribution on both sides of a three-purpose automotive light engine for three different PCB approaches having different materials but the same geometry. Both results showed that FR4 PCB has a temperature gradient (TMaxBoard to TAmbient) of over 63 °C. Moreover, a number of local hotspots occurred over FR4 PCB due to low thermal conductivity. Later, a metal core PCB is investigated to abate local hot spots. A further study has been performed with an advanced heat spreader board based on vapor chamber technology. Results showed that a thermal enhancement of 7.4% and 25.8% over Al metal core and FR4-based boards with the advanced vapor chamber substrate is observed. In addition to superior thermal performance, a significant amount of lumen extraction in excess of 15% is measured, and a higher reliability rate is expected.

scholarly journals A programmable light engine for quantitative single molecule TIRF and HILO imaging

2008 ◽  
Vol 16 (22) ◽  
pp. 18495 ◽  
Author(s):  
Marcel van 't Hoff ◽  
Vincent de Sars ◽  
Martin Oheim
Keyword(s):  
Single Molecule ◽  
Light Engine

SCALABLE: Self-Calibrated Adaptive LIDAR Aperture Beamsteering Light Engine

2019 ◽  
Author(s):  
K.H. Wagner ◽  
N. Dostart ◽  
B. Zhang ◽  
M. Brand ◽  
D. Feldkhun ◽  
...  
Keyword(s):  
Light Engine

Laser Driven Static Light Engine Based on LuAG:Ce Single Crystal Phosphor

2017 ◽  
Author(s):  
A. Burak Cunbul ◽  
Mustafa H. Balcı ◽  
Xuyuan Chen ◽  
Øyvind Svensen ◽  
M. Nadeem Akram
Keyword(s):  
Single Crystal ◽  
Crystal Phosphor ◽  
Light Engine

Thermal Enhancement of an LED Light Engine for Automotive Exterior Lighting With Advanced Heat Spreader Technology

2016 ◽  
Author(s):  
Umut Zeynep Uras ◽  
Enes Tamdoğan ◽  
Mehmet Arık
Keyword(s):  
Thermal Conductivity ◽  
Numerical Models ◽  
Maximum Temperature ◽  
Vapor Chamber ◽  
Metal Core ◽  
Heat Spreader ◽  
Printed Circuit ◽  
Thermal Enhancement ◽  
Wide Range ◽  
Light Engine

In recent years, light emitting diodes (LEDs) have become an attractive technology for general and automotive illumination systems. LEDs have been preferable for automobile lighting due to its numerous advantages such as long life, low power consumption, optical control and light quality as well as robustness for high vibration. Thermal management is one of the main issues due to severe ambient conditions and compact volume. Conventionally, tightly packaged double sided FR4 based printed circuit boards are utilized for both driver electronics components and LEDs. In fact, this approach will be a leading trend for advanced Internet of Things (IOT) applications in near future. A series of numerical models are developed to determine the local temperature distribution on both sides of a light engine. Results showed that FR4 PCB has a temperature gradient of over 63°C while the maximum temperature is 105°C. This causes a significant degradation of lifetime and lumen extraction as many LEDs are recommended to be operated below 100°C. In addition to FR4, Aluminum metal core and vapor chamber based advanced heat spreader substrates are developed to obtain thermal impact on the substrate due to a wide range of thermal conductivity of three boards. To mimic real application, two special flex circuits are developed for LEDs and driver circuit. 10 red and 6 amber LEDs at one flex-PCB, and driver components are populated on the other flex-PCB are mounted. Both flex circuits are attached each side of the substrate. Experimental results showed that the local hotspots occurred at FR4 PCB due to low thermal conductivity. Later, a metal core printed circuit board is investigated to minimalize local hot spots. High conductivity metal core PCB showed a 19.9% improvement over FR4 based board. A further study has been performed with an advanced heat spreader based on vapor chamber technology. Results showed that a thermal enhancement of 7.4% and 25.8% over Al metal core and FR4 based boards with an advanced vapor chamber substrate.

Sign in / Sign up

Export Citation Format

Share Document