• Journal of the Ergonomics Society of Korea
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• v.31 no.3
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• pp.421-426
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• 2012

As headlamp technology advances, newly developed various headlamps were introduced in the market. The objective of this study is to quantitatively analyze the detection distance of the recently developed LED headlamps and existing headlamps, complying with specific technical standard. Background: The detection distance of headlamps is very important to prevent automobile accident at night time. The studies of detection distance of LED, Halogen and HID headlamp have been conducted, but no study has shown the detection distance of pedestrian target with various colors (Black, White, Blue). Method: The experiment of detection distance was conducted with 30 people, which divide into 2 groups as 15 men and 15 women. Automatic transferable target on the rail was manufactured in order to reduce the error of study's result, and ANOVA also conducted to analyze the main effect with sign color, sex and headlamp classified by detection distance. In addition, the luminance by average detection distance was measured as well. Results: The detection distance of headlamps was HID > LED > Halogen. The luminance measure of LED headlamp was lower than HID and Halogen headlamps. Conclusion: The headlamp performs a very significant role for safety at night time but it needs to be improved through assessment of visual characteristics. Also, it needs to be suggested the need of test method for dynamic detection distance concerning technical development is suggested.

• Transactions on Electrical and Electronic Materials
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• v.15 no.5
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• pp.270-274
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• 2014

Currently, LED headlamps are only attached to newly manufactured vehicles, and it remains difficult to mount LED headlamps on used cars. Therefore LED headlamps need to be developed for used cars as a replacement of their halogen lamps. Due to a number of spatial limitations, it is critical to ensure a certain level of thermal performance. In order to obtain a design for efficient heat radiation, this paper aimed to optimize thermal management through a combination of heat sinks, heat pipes and fans. Based on such a design, this paper succeeded in developing LED headlamps of the desired performance to replace the halogen bulbs of used cars.

• Proceedings of the IEEK Conference
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• 2000.11d
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• pp.69-72
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• 2000

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.

• 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.

• 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.

• Journal of the Korean Society for Railway
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• v.19 no.1
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• pp.46-53
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• 2016

LED light sources have been known to have a long life and good energy efficiency compared to traditional light sources. Recently, headlamps using LED light sources have ensured the forward visibility and safe operation of high-speed rolling stock. However, assessing the lifespan of LED headlamps based on real test data is not easy because it depends on the multiple stress factors such as a fixed driving current, junction temperature, vibration and so on. Generally, LED headlamps have failed before their advertised life span mainly due to temperature. Thus, the performance assessment of a temperature control unit should be done before a life cycle test of LED headlamps. This study attempted to develop a prototype temperature control module for a lifecycle test system using a commercial LED headlight and verified the system through experiments.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.4
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• pp.159-165
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• 2013

One of the leading causes of night time automobile accidents is the darkness of surroundings. Headlamps play a critical role in casting light and providing drivers with visibility. Headlamp design and new technology have been developed recently as research has been actively carried out to increase headlamp recognition. This study statistically analyzes irradiation distance using computer simulation by categorizing headlamps applied in domestic automobiles in the last decade by year, light source, form, vehicle type, and height of installation. After analyzing results of irradiation distance, it appears irradiation distance has been increased by approximately 10m in the last decade. This increase in irradiation distance is predicted to decrease night time accidents by allowing more time to recognize potential causes of accidents.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.5
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• pp.890-896
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• 2010

Increasing styling features for automotive headlamps speed up the focus of understanding condensation at inner surfaces. Water vapor condensation on the inside surface of the headlamp lens is an essential factor that affects secure front view and headlamp life. One of the headlamps of automobile which is one of the most popular in Korea was chosen for the present analysis. In the basis of the experimental data of automobile given by a manufacturer, boundary conditions were defined and free convection of the air inside the headlamp and radiation from the bulb to the other surfaces are considered. As a result, temperature distribution of the inside surface of the headlamp lens are approximately the same as the experimental result.

• Journal of the Korean Society for Railway
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• v.18 no.2
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• pp.111-116
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• 2015

LED luminaires as a lighting system have attracted much research attention due to their high efficiency and long lifetimes. However, disappointing outcomes have been noted in terms of performance levels and lifetimes as compared to desired system requirements in practice due to certain electrical and thermal characteristics of LEDs. LM-80 and TM-21 established by IESNA are the best known standards for lifetime test procedures and estimation techniques. However, they only handle LED light sources without guaranteeing the LED luminaire in a reliability test. They also operate for more than 6,000 hours and undergo various stresses, such as the operating current and temperature. Therefore, a lifetime standard for LED luminaires has not yet been established. This paper proposes a conceptual design of a lifetime test system for LED headlamps depending on the operating environment. Eventually, this method can assist with evaluations of the validity of lifetime standard tests of LED headlamps.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2008.05a
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• pp.184-185
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• 2008

본 논문에서는 전조등의 밝기변동이 다양한 패턴을 가지고 주기적으로 발생하였을 경우에 대한 운전자의 심리적 반응을 파악하였다. 그 결과 조도변동의 발생빈도가 어떠한 패턴으로 발생하더라도 불쾌감에 미치는 영향은 동일하고 2번 이상 조도변동이 발생하면 불쾌감은 한 번 발생하였을 때 보다 증가하였다.