• Journal of the Optical Society of Korea
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• 제19권4호
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• pp.421-426
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• 2015

This paper presents a hybrid single optical system for an LED surgical light that combines the advantages of both lens- and reflector-type single optical systems. The proposed hybrid single optical system includes a lens in the center and the LED light originating from the lens is redirected using a reflector to achieve a high beam spread. Iterative optical software simulations are used to provide data for the design of the lens and reflector for a single optical system, and for a complex optical system for the LED light assembly. The resulting data is also used to fabricate a prototype system. Experiments using the prototype of the hybrid single optical system and a mock-up LED surgical light confirm the system's shadow dilution performance and its applicability to surgical operations.

• 새물리
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• 제68권11호
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• pp.1268-1274
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• 2018

항공장애등이란 비행 중인 조종사에게 건축물이나 위험물의 존재를 알리기 위해 사용되는 등화를 말한다. 현재 대부분의 항공장애등의 광원은 발광다이오드(light-emitting diode, LED)로 대체되었고, 급격하게 확장 및 보급되었으나, 설치된 항공장애등이 광학적 성능 기준을 충족하지 못하여 항공 수송기기의 충돌 사고를 유발하고 있으며, 이러한 이유로 항공 안전상의 위험에 노출되어 있는 실정이다. 이러한 문제를 해결하기 위하여 본 연구에서는 $360^{\circ}$ 방향에서 동일한 광도 분포를 가지고, LED 광원에서 나오는 광선을 좁은 빔(beam) 발산각으로 시준할 수 있는 프레넬 렌즈(fresnel lens)를 각각의 비구면 조각의 집합 (array) 형태로 설계를 하였다. 그 후에, 렌즈 기울기(tilt), LED와 프레넬 렌즈 사이의 거리를 최적화하여 중심 광도 20,000 cd, $3^{\circ}$ 이상의 수직 빔 발산각을 구현하는 항공장애등 광학계 설계와 시뮬레이션을 진행하였다.

• Current Optics and Photonics
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• 제1권3호
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• pp.233-238
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• 2017

In this paper we propose a freeform secondary lens for an LED fishing/working lamp (LFWL). This innovative LED lamp is used to replace the traditional HID fishing lamp, to satisfy the lighting demands of fishing and the on-board activities on fishing boats. To realize the freeform lens's geometry, Gaussian decomposition is involved in our optics-design process for approaching the targeted light intensity distribution curve (LIDC) of the LFWL lens. The simulated results show that the illumination on the deck, on the sea's surface, and underwater shows only small differences between LED fishing/working lamps and HID fishing lamps. Meanwhile, a lighting efficiency of 91% with just one third of the power consumption can be achieved, when the proposed LED fishing/working lamps are used instead of HID fishing lamps.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.72-75
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• 2009

In this paper, we have designed a novel lens for LED's package that can expend the radiation angle of LED from $120^{\circ}$ to $170^{\circ}$ successfully. At the same brightness and uniformity condition of 37" LED BLU system, using novel lens LED package can be reduced amounts of LED 40% or thickness of BLU 30% respectively. Besides, the power consumption of BLU also can be reduced 25%.

• Journal of the Optical Society of Korea
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• 제20권6호
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• pp.739-744
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• 2016

We have designed a new TIR(Total Internal Reflection) structure for generating an LED lens which can produce a rectangular beam with small divergence angle in two perpendicular directions for an optical guidance system. The lens can control the divergence angle in the horizontal direction to be a small value of about $8^{\circ}$ with a $1mm{\times}1mm$ LED source, also in the vertical direction it can be about $7^{\circ}$, with optical collection efficiency higher than 0.83. After the lens is manufactured, the work demonstrates that the lens is suitable for an optical guidance system.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 하계학술대회 논문집
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• pp.289-289
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• 2009

Light emitting diode(LED) has many advantages including lower energy consumption and longer lifetime and eco-friendly in comparison with traditional light sources. Spheric plastic lens generally used in LED lighting occurs aberration and ghost image which give displeasure and deteriorate vision quality in human eyes. Using the optical program (LightTools$^{TM}$, CodeV$^{TM}$), we were confirm the aberration and ghost image in optical simulation and employed aspheric lens form in the lens design to improve these problems. From the comparison of the simulation results between the aspheric lens and the spheric lens, we were ascertain to be improved both aberration and Ghost image.

• 한국전기전자재료학회논문지
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• 제21권1호
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• pp.35-43
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• 2008

Aviation obstacle lights including controller for the safe night aviation service have applied to high voltage transmission line of which height is from $60{\sim}180 m$, Fresnel lens made by Augustine Fresnel have been applied to light houses, These Fresnel lens were applied to aviation obstacle lights and have been universally used, It was reported that Fresnel lens for aviation obstacle light was used in the first place in Korea in 1987, LEDs have recently been applied to aviation obstacle lights, So, the optimum physical design is essential to the design of aviation obstacle light. In this study, optical and three dimensional modeling of LED module and globe lens were performed, And thermal analysis due to LED thermal source and service thermal condition in high voltage transmission line was performed and was analyzed comparing with experiments, The optimum design process of medium intensity LED aviation obstacle lights was constructed with three dimensional modeling, thermal analysis, and thermal experimental technique.

• 한국산학기술학회논문지
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• 제13권1호
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• pp.296-305
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• 2012

본 연구에서는 기존 LED 보안등의 LED 광원 직진성에 의한 눈부심 현상을 개선하고, 조도 균제도를 높게 유지하며, 회전 대칭이 아닌 편축으로 긴 배광 분포를 가지도록 하여 LED 보안등 간에 생기는 광 공핍현상을 해결할 수 있는 보안등용 LED 2차 렌즈를 개발하였다. 개발 광학계는 보안등용 조명 기준에 만족하도록 설계하였으며, 렌즈의 형태는 단일 렌즈로 조명 설계 및 해석 프로그램을 이용한 설계와 분석을 통해 최적화를 하였다. Mock-up을 제작하여 실제 측정을 통해 조도 측정 데이터와 조도 균제도 데이터를 확보하였다.

• 한국정밀공학회지
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• 제29권11호
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• pp.1170-1173
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• 2012

We have investigated the LED lens eccentricity effect on light intensity distribution. For the purpose, we introduced an equation of focal length for paraboloid, and then made a comparative analysis of the theoretical result and 3-D simulation result.

• 한국광학회지
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• 제24권1호
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• pp.29-38
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• 2013

본 논문에서는 점광원을 기준으로 설계된 자유 형상 렌즈(freeform lens)의 조명 성능과 LED 광원 크기와의 관계 및 공차 특성을 살펴보았다. 비교를 위해 발산 조명 모델(divergent illumination model)을 적용한 두 가지 렌즈와 중첩 조명 모델(overlapped illumination model)을 적용한 한가지 렌즈를 설계하였다. LED 광원이 커짐에 따라 평균 조도에 비해 조도 균일도가 상대적으로 크게 감소하였으며, 정렬 오차에 의한 성능 저하는 거의 발생하지 않았다. 하지만 LED 광원의 방출 특성 변화는 LED 광원 크기에 관계없이 조명 성능에 영향을 미치는 것으로 확인하였다. 발산 조명 모델로 설계된 렌즈가 전반적으로 우수한 성능을 보였지만, LED 방출 특성 변화에 대해서는 중첩 조명 모델로 설계된 렌즈의 성능이 상대적으로 적게 변화함을 알 수 있었다.