• The Optical Journal
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• s.145
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• pp.31-35
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• 2013

최근 자동차에 사용되는 조명은 LED가 주를 이루고 있다. 자동차 실내조명, 계기판 등에 사용되는 내부 조명의 경우 대부분 LED를 적용한 제품이며, 헤드램프, 후방 램프 및 방향 지시등과 같은 외부 조명의 경우도 LED로 교체되고 있다. 특히 LED 기반 헤드램프의 경우 과거 3500cc 이상 승용차 등에 한정되었으나 현재는 그 이하 레벨의 승용차 및 SUV 차량으로 범위가 빠르게 확산되고 있다. 고효율, 긴 수명 및 빠른 응답 속도가 장점인 LED를 차량용 조명 광원으로 사용함으로써 기존 할로겐램프나 HID 광원의 대체재로서의 전환이 활발히 이루어지고 있다. 할로겐램프의 경우 청색보다 적색 파장의 광량이 많은 관계로 황색에 가까운 백색을 보이며, HID 램프의 경우 할로겐램프보다는 백색 계열에 더 가깝다. 하지만 LED 램프는 파장의 순도가 높아 보다 완벽한 백색 구현이 가능하다. 또한 단순한 기능을 지닌 헤드램프에서 지능형 헤드램프로의 발전이 빠르게 이루어지고 있다. 이에 따른 LED의 수요 또한 증가할 것으로 예상된다. 향후 고효율 LED 소자의 개발과 함께 자동차용 LED 조명에 대한 적용은 급속도로 진행될 것으로 예상되며, 앞으로 자동차 조명 분야에서는 'LED 헤드램프/후미등 기술+IT 기술(센서+통신)'이 융합된 형태로 발전할 것이다. 본고에서는 LED 자동차 융합 기술 동향 및 전망에 대해 자세히 기술하였다.

• Proceedings of the KIPE Conference
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• 2015.07a
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• pp.93-94
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• 2015

최근 자동차 조명시장에서 LED를 이용한 헤드램프 개발이 빠르게 이루어지고 있다. LED 헤드램프는 기존의 할로겐 앰프와 다르게 에너지 효율이 높으며, 헤드램프뿐만 아니라 차량 내부에 다양하게 활용이 가능하다는 장점을 갖는다. 현재 차량에 적용되어 있는 LED 헤드램프 대부분은 SEPIC을 이용한 LED전류제어를 한다. 이러한 경우 헤드램프의 효율은 SEPIC에 의해 대부분 결정이 되며, 부수적인 기능추가를 위해서는 보조 ECU가 추가적으로 필요하다. 따라서 본 논문에서는 차량용 헤드램프를 위한 DC/DC컨버터를 제안하고, 이에 대해 검증한다.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.38 no.6
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• pp.630-639
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• 2001

This study proposes a new calculation method for generating real nighttime lamp-lit images. In order to improve the color appearance in the prediction of a nighttime lamp-lighted scene, the lamp-lit image is synthesized based on spectral distribution using the estimated local spectral distribution of the headlamps and the surface reflectance of every object. The Principal component analysis method is introduced to estimate the surface color of an object, and the local spectral distribution of the headlamps is calculated based on the illuminance data and spectral distribution of the illuminating headlamps. HID and halogen lamps are utilized to create beam patterns and captured road scenes are used as background images to simulate actual headlamp-lit images on a monitor. As a result, the reproduced images presented a color appearance that was very close to a real nighttime road image illuminated by single and multiple headlamps compared to the conventional graphic-based algorithm.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2003.11a
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• pp.19-23
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• 2003

헤드램프는 안개등, 후미등, 제동등, 방향지시등과 함께 자동차의 등화장치 중의 하나로써 특히 야간의 안전운행을 위해 필수적인 장치이다. 야간 운전시 차량의 운전자는 마주오는 차량의 헤드램프에 의한 눈부심으로 도로의 사정을 정확히 파악할 수 없는 일이 종종 발생하게 되는데 이것은 야간 사고의 큰 원인으로 지목된다. 그러므로 헤드램프의 빔패턴은 정확하고 sharp한 cut-off line을 가져야 한다. 본 논문에서는 미국식 빔패턴(SAE type)을 고려한 헤드램프용 반사갓 설계의 한가지 알고리즘을 제시한다.

• Transactions of the Korean Society of Automotive Engineers
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• v.22 no.7
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• pp.23-30
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• 2014

"Cut off line" in automotive passing beam has very important safety function because it serves for headlamp aiming. Headlights that are aimed incorrectly will not only perform poorly but also offend oncoming traffic. In addition, an objective definition of cut off line in low beam is necessary, since a requirement for correct aiming of the beams is specified within all the existing regulations. Accordingly, headlight regulations are requirements that automobiles must satisfy in order to be sold in a particular country. In this study, a more advanced recognition method for the cut off lines of the various headlamps commonly used in Europe, North America, and domestic is suggested and a headlamp testing system is developed to adjust the beam to the country-specific regulation. This system uses image processing technology to detect the cut off lines in the beam patterns of halogen headlamps, high-intensity discharge headlamps, and light-emitting diode headlamps as well.

• Korean Journal of Optics and Photonics
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• v.30 no.1
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• pp.8-14
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• 2019

This paper presents methods to correct and evaluate the chromatic aberration occurring on the cut-off line of a headlamp without additional optical components and alignment process. To correct the chromatic aberration using a geometrical concept, the maximum differences in exit-ray angle between wavelengths are reduced by tilting the convex surface of an aspheric projection lens. To evaluate the chromatic aberration, the position and luminous intensity to be measured are suggested, and the criterion for chromatic aberration is presented through color coordinates. From the evaluation of an automotive headlamp designed using this geometrical method, it is found that the chromatic aberration of the cut-off line is significantly reduced.

• Journal of IKEEE
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• v.27 no.4
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• pp.368-378
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• 2023

Automotive headlamp with LED matrix exploits low-cost low-speed serial buses such as I2C and SPI for digital LED control. When headlamp resolution increases, LED control data significantly increases to exceed capacity of control bus. This paper proposes HLCP (Headlamp LED Control Protocol), a novel LED maxtrix headlamp protocol. The proposed protocol exploits dedicated instructions to control many LEDs simultaneously, so it can control much more LEDs than conventional control buses although it is basically based on I2C bus. It is designed and verified in Verilog HDL. Simulation results show that HLCP can control LED matrix headlamp more efficiently than I2C and SPI.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.443-444
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• 2006

The influence of the heat sources on LED junction temperature are Engine room air, Back plate, Electric power device, and so on. LED lamp cooling system is considered to be an important subject fur high light efficiency. Because LED Chip will be problem When LED junction temperature be over $135^{\circ}C$, In this Study, The Looped Heat Pipe System is considered to prevent LED Chip fall. The LHPS is consist of evaporator part, condenser part, heat pipe part. The working fluid of LHPS is HCFC-123. In this study, to prevent LED Chipfall, we study thermal characteristics for Looped Heat Pipe System with LED lamp.

• Journal of ILASS-Korea
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• v.16 no.2
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• pp.90-96
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• 2011

Atomized liquid jets from the washing nozzle which configured with recirculation chamber for cleaning hot-zone area are accelerated and impinged on the head lamp surface. Cleaning efficiency of head lamp can be increased with injecting washing fluids into the hot-zone area. Experimental and numerical studies with various design parameters were executed to reveal the relations between internal geometry and internal flow in the washing nozzle. Spray structures were fitted with each of the head lamp surfaces and spray nozzles were optimized to the spray pattern. The recirculation chamber induces a recirculation flow and can be decreased the pressures perturbation inside the chamber. Orifice determines the mass flow rate. When the diameter of orifice is excessively large, it showed an unstable spray pattern. As a nozzle exit angle increases, density distributions are separated with two section. Also, as a protrusion length of nozzle exit increases, spray patterns are spread into a large area and density distributions showed unstable trend.

• Electrical & Electronic Materials
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• v.25 no.8
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• pp.5-11
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• 2012