연속마이크로렌즈를 이용한 네비게이터용 7인치 LCD-BLU용 금형개발

김종선(J. S. Kim),고영배(Y. B. Ko),황철진(C. J. Hwang) 대한기계학회 2006 대한기계학회 춘추학술대회 Vol.2006 No.6

LCD-BLU (Liquid Crystal Display - Back Light Unit) is one of kernel parts of LCD unit and it consists of several optical sheets(such as prism, diffuser and protector sheets), LGP (Light Guiding Plate), light source (CCFL or LED) and mold frame. The LGP of LCD-BLU is usually manufactured by forming numerous dots with 50~300 um in diameter on it by etching process. But the surface of the etched dots of LGP is very rough due to the characteristics of the etching process during the mold fabrication, so that its light loss is high along with the dispersion of light into the surface. Accordingly, there is a limit in raising the luminance of LCD-BLU. In order to overcome the limit of current etched dot patterned LGP, optical pattern design with continuous micro-lens was applied in the present study.

Fabrication of micro injection mold with modified LIGA micro-lens pattern and its application to LCD-BLU

윤경환,김종선,고영배,황철진,김종덕 한국유변학회 2007 Korea-Australia rheology journal Vol.19 No.3

The light guide plate (LGP) of LCD-BLU (Liquid Crystal Display-Back Light Unit) is usually manufactured by forming numerous dots by etching process. However, the surface of those etched dots of LGP is very rough due to the characteristics of etching process, so that its light loss is relatively high due to the dispersion of light. Accordingly, there is a limit in raising the luminance of LCD-BLU. In order to overcome the limit of current etched-dot patterned LGP, micro-lens pattern was tested to investigate the possibility of replacing etched pattern in the present study. The micro-lens pattern fabricated by the modified LiGA with thermal reflow process was applied to the optical design of LGP. The attention was paid to the effects of different optical pattern type (i.e. etched dot, micro-lens). Finally, the micro-lens patterned LGP showed better optical qualities than the one made by the etched-dot patterned LGP in luminance.

측면조광 LED BLU 얼룩 현상 개선을 위한 최적 방열 설계에 관한 수치해석 연구

김현기(Hyun Ki Kim),이종희(Jong Hui Lee),박일석(Il Seouk Park) 대한기계학회 2018 大韓機械學會論文集B Vol.42 No.11

본 연구에서는 측면조광 LED(Light Emitting Diode) BLU(Back Light Unit)의 광원으로 사용되는 LED PKG(Package)의 국부적인 발열로 인해 BLU 내부에서 발생하는 sheet 주름과 이로 인한 얼룩 현상을 개선하고자 한다. 국부적인 발열 문제를 해결하기 위해 metal chassis의 두께, 길이, 열전도도 변화에 따른 LED BLU 내부의 전도열전달 특성을 수치해석적으로 검토하여 최적 방열 설계 조건을 도출하였다. Metal chassis 두께와 길이가 증가할수록 방열 면적이 증가하여 전체 온도는 감소하고, 열전도도가 증가해도 전체 온도가 감소하는 것을 확인하였다. 연구를 통해 sheet 주름과 얼룩현상의 주원인자인 온도의 적정 수준 관리를 위한 metal chassis 두께, 길이, 열전도도 간의 상관관계식을 도출하였다. This study aims to improve sheet wrinkles and mura due to the internal heat of light-emitting diode (LED) package (PKG), which is used as a light source of a side-lighting LED (back light unit) BLU. In order to solve the local heating problem, the variations of the conduction heat-transfer characteristics inside the LED BLU with the thickness, length, and thermal conductivity of the metal chassis are numerically investigated, and optimum heat dissipation design conditions are derived. As the thickness and length of the metal chassis increased, the total area of the heat sink decreased, and the overall temperature decreased as the thermal conductivity increased. Based on the results of this study, the correlation equation relating the thickness, length, and thermal conductivity of the metal chassis for the proper management of temperature, which is the main cause of sheet wrinkles and the mura phenomena, is derived.

LED와 아크릴을 이용한 광고용 BLU 시스템 구현

김한나,이학재,Kim, Han-Na,Lee, Hyuek-Jae 한국융합신호처리학회 2010 융합신호처리학회 논문지 (JISPS) Vol.11 No.4

본 논문은 LED와 아크릴을 이용한 새로운 BLU을 제안하고 그 가능성을 실험적으로 검증했으며, 특히 LED에 의한 아크릴의 빛 산란 및 가이딩에 관한 연구에 초점을 맞췄다. 기존 형광 램프를 이용한 BLU는 현재 많이 개발되어 있는 상황이나, 이러한 BLU 제품은 구입 가격이 높고 수명이 짧으며, 벽에 부착할 경우 두꺼워 부착하기가 쉽지 않다. 또한, 실외에서 사용하기 위해서는 외부의 환경으로부터 보호될 수 있는 별도의 패키징이 필요하다. 본 논문에서는 저렴한 비용으로 옥외 간판의 BLU로 활용될 수 있는 새로운 BLU 시스템을 제안하고 검증한다. 장치의 구성은 매우 저렴하게 구입할 수 있는 아크릴과 LED로 이루어지며, 빛의 산란 효과를 이용하기 위하여 아크릴 표면에 다양한 스크래치를 시도하였다. 또한, 인터넷을 통하여 BLU의 색상, 조도를 다이나믹하게 원격 조정할 수 있도록 임베디드 시스템을 구현 하였다. 모의실험의 결과를 바탕으로 간판용 BLU를 실제 구현하였고, 모의실험의 경우 2,673Lux, 실제 제작한 광고용 BLU는 2,554Lux의 평균 밝기가 측정되었다. 모의실험 결과와 실제 제작된 BLU의 실험 결과가 유사하게 나타남을 확인 할 수 있었다. This paper has proposed and experimentally demonstrated a new BLU using an LED and an acryl, which is specially focused on the implementation about the guiding effect of an acryl luminous by the LED. While the conventional BLU using a fluorescent lamp is generally and widely used, it shows big power consumption with a short life even more too thick to hold on the wall. To solve such demerits, we propose a new method for a BLU using an LED and an acryl in this paper. This BLU system has various scratches on the surface of acryl to get diffusion effect of light, and has been included an embedded board that can dynamically control the colors and the intensity of the BLU through the Internet. We have conducted computer simulations to find out the optimal scratch pattern on the surface of the acryl for the backlight system. Based on the resulted out simulation. The the optimal scratch pattern signs has been developed. The simulation result shows 2,673Lux an average for a luminous intensity test, and the other hand, experiential result shows 2,554Lux. From the experiments, it is possible for the proposed BLU system to be used for real advertisements.

측면 발광 POF 광원장치의 측면가공조건에 따른 LGP의 광학적 특성

박소희 한국물리학회 2016 새물리 Vol.66 No.10

When a light source is inserted into the side of a light guide plate (LGP), the emitted light has a planar optical form. Therefore the LGP faces the problem of decreased optical efficiency when a large amount of light is concentrated on it. In this study, one light-emitting diode was placed at each end of a light-emitting plastic optical fiber (POF), and the light source device with the POF was coupled to the LGP by processing the line pattern in the cladding layer. It was then selected for the appropriate line patterning processing parameters in order to analyze the optical properties under optimized processing conditions. A simulation was performed to determine the amount of light inside the LGP by using the emitted light obtained by processing the line pattern. As a result, the amount of light loss inside the LGP can be minimized, which can improve the illuminance distribution. 도광판(Light guide plate, LGP) 측면에 광원을 삽입하는 경우 출사되는 빛이 평면광 형태로 형성되기 때문에 입광부에 다량의 광이 편중되어 광학적인 면에 있어서 효율성이 저하되는 등의 문제점을 가지고 있다. 본 연구에서는 이러한 문제점을 개선하고자 측면 발광형 플라스틱 광섬유(Plastic optical fiber, POF)의 양단 끝에 두 개의 LED를 배치시켜 클래딩층에 라인 패턴을 가공한 POF 광원장치를 도광판 측면에 결합시키고, 적합한 라인 패터닝 가공변수를 선정하여 전산모사를 통해 최적화된 측면가공조건에 대한 광학적 특성을 분석하였다. 가공된 라인 패턴으로부터 출사되는 광을 이용하여 도광판 내부에 미치는 상관관계를 도출하고자 전산모사 한 결과 도광판에 LED를 직접 삽입하는 경우에 비해 도광판 내부에서의 광량 손실도 최소화 하면서 조도분포가 개선되는 것을 확인하였다.

광학적 패턴의 산란각에 따른 LCD Backlight용 도광판의 휘도 정량화 분석

박소희,신용진 한국물리학회 2014 새물리 Vol.64 No.9

We implemented an optical scattering pattern design in a light guide plate (LGP) to enhance the luminance measurement accuracy by optimizing the structure of the LGP, functions as a surface light source in an edge-type backlight unit (BLU). We then reduced the number of optical sheets and analyzed the luminance and the homogeneity of the outputs, thereby varying the machining conditions via computer simulations. The analysis revealed that the BLU using the laser-machined LGP was greatly influenced by the pattern's shape and scattering angle, even under the same machining conditions. Furthermore, for the design of the pattern, by adjusting the scattering angles so that they were distributed on a curved surface, we minimized the LPG light loss, improved the luminance characteristics, and reduced the number of patterns. 에지형 백라이트유닛 (BLU; Backlight unit)에 사용되어 면광원 기능을 하는 도광판 (LGP; Light Guide Plate)의 구조를 최적화하여 향상된 휘도 정량화를 위한 광학적 산란패턴의 도광판을 설계하였다. 또한 광학시트를 줄이고 가공 조건에 따른 휘도와 균일도에 대해 전산모사를 통해 분석하였다. 그 결과 레이저로 가공된 도광판을 이용한 BLU는 동일한 가공 조건임에도 패턴 형상과 산란각도에 따라 지대한 영향을 받게 됨을 확인 할 수 있었다. 또한 산란각을 조절한 패턴을 곡면으로 분포하도록 설계하여 패턴의 개수를 줄이면서도 도광판 내부에서의 광량의 손실을 최대한 줄이고 휘도 특성을 향상시킬 수 있었다.

박막 적증 비대칭 Extmded-closed-polyon 형 BLU 도광판에 관한 연구

배창환(Chang Hwan Bae) 호서대학교 공업기술연구소 2009 공업기술연구 논문집 Vol.28 No.1

W e p rop osed the lam inate thin film asy m m e tric E x tru d e d -c lo se d -p o ly g o n d iffu sio n pattern that w a s able to im p ro ve the p erfo rm an ce o f b a c k ligh t unit. D e v e lo p e d a pattern o f b rig h tn ess an d b righ t line,h a lf-p o w e r an g le attribute the im p ro ved p erfo rm an ce thin u lm stack aole d ifftision la y e r 9 7 0 % im p ro ve d h o rizon tality b rightness.

SCS micro-lens 패턴적용 휴대폰 도광판 제작용 미세금형 제작에 대한 연구

오정길(J.G. Oh),김종선(J.S. Kim),윤경환(K.H. Yoon),황철진(C.J. Hwang) 한국소성가공학회 2010 금형가공 심포지엄 Vol.2010 No.11

BLU(Back Light Unit) is one of kernel parts of LCD(Liquid Crystal Display) unit. New 3-D micro-lens pattern for LGP(Light Guide Plate), one of the most important parts of LCD-BLU, was proposed and applied to injection mold. Instead of dot pattern made by chemical etching or laser ablation, the SCS(Slanted Curved Surface) micro-lens as micro-optical unit of LGP was applied and designed for optical CAE simulation. The method of optical design using optical CAE simulation for the SCS micro-lens, the new fabrication method of micro-mold with SCS micro-lens pattern was introduced and basic geometric aspects of the SCS micro-lens for LGP pattern was discussed.

Fabrication of micro injection mold with modified LIGA micro-lens pattern and its application to LCD-BLU

Kim, Jong-Sun,Ko, Young-Bae,Hwang, Chul-Jin,Kim, Jong-Deok,Yoon, Kyung-Hwan The Korean Society of Rheology 2007 Korea-Australia rheology journal Vol.19 No.3

The light guide plate (LGP) of LCD-BLU (Liquid Crystal Display-Back Light Unit) is usually manufactured by forming numerous dots by etching process. However, the surface of those etched dots of LGP is very rough due to the characteristics of etching process, so that its light loss is relatively high due to the dispersion of light. Accordingly, there is a limit in raising the luminance of LCD-BLU. In order to overcome the limit of current etched-dot patterned LGP, micro-lens pattern was tested to investigate the possibility of replacing etched pattern in the present study. The micro-lens pattern fabricated by the modified LiGA with thermal reflow process was applied to the optical design of LGP. The attention was paid to the effects of different optical pattern type (i.e. etched dot, micro-lens). Finally, the micro-lens patterned LGP showed better optical qualities than the one made by the etched-dot patterned LGP in luminance.

LCD 도광판 두께에 따른 휘도 및 잔류응력에 관한 연구

이중원(Joong Won Lee),박명균(Myung Kyun Park),김정훈(Jung Hoon Kim) Korean Society for Precision Engineering 2008 한국정밀공학회지 Vol.25 No.9

Light guide plate is one of most important components which are composed of back light unit, affecting the quality and performance of LCD. Average brightness and uniformity are especially key factors for designing the light guide unit. These qualities are affected and controlled by the pattern being attached to the back of light guide unit. In order to obtain high brightness and uniformity the optimized pattern design is adopted for LGP. In this study, optimized molding condition for LGP with 0.4 ㎜ thickness was obtained by using the Moldflow simulation software and the optimized pattern for better brightness uniformity was designed for the thickness of the 0.4 ㎜ by trial and error method. The brightness was measured for the different LGP thicknesses and the residual stress analysis was performed for 0.4 ㎜ thickness by the photoelasticity and the results are compared with 0.5 ㎜, 0.6 ㎜ thickness.