의료기기 LCD 패널용 LED 후면광 배열과 구동회로의 설계 및 제작

류장렬(Jang-Ryeol Ryu),이부형(Boo-Hyung Lee),이광규(Kwang-Kyu Lee) 한국정보기술학회 2010 한국정보기술학회논문지 Vol.8 No.4

LEDs are using widely in field of illumination, optical source of medical instrument and LCD backlight because they have several merits such as low power consumption, long lifetime, high brightness ratio, fast response, environment friendly and complex structure, individual driving circuit, slow response time, difficult of low-temperature operation for CCFL. For using them as a optical source of inspections equipment for LCD panel, the design of excellent backlight system, brightness uniformity and high power and good protection against heat is essential. In this paper, backlight system which is built in the 15 inch side emitting LCD backlight by LED array structure and driving circuit were designed and developed. After that, their performances were measured. It showed the luminous intensity uniformity of 91%, dimming range of 27 cd/m2~515 cd/m2 and black level of 0.1 cd/m2~0.7 cd/m2 thermal test of 54℃ over values.

목차 : 트리억제제가 첨가된 LDPE의 방사선 조사에 따른 절연특성 변화

류부형 ( Boo Hyung Ryu ) 한국안전학회(구-한국산업안전학회) 2012 한국안전학회지 Vol.27 No.2

The effectiveness of treeing resistance in low density polyethylene containing azocompounds were investigated under radiation environments, 4-(4-nitrophenylazo)-1-naphthol and 4-(4-nitmphenylazo) resorcinol were selected for treeing inhibitors, LDPE containing the additives were crosslinked with dicumyl peroxide, irradiated by Co60 y-ray in the presence of air at room temperature, Treeing inception voltage, AC breakdown strength measurements were carried out for electrical insulation characteristics, thermoluminescence and gel contents were analyzed as various irradiation doses also. LDPE with treeing inhibitors showed much better insulation characteristics than pure LDPE. It is interpreted that molecular structures, polar groups and the type of radicals connected on the benzene ring of the additives affected ele-ctrical characteristics. From the results, 4-(4-nitmphenylam) resorcinol was the most effective upon the best treeing and radiation resistance.

대면적 LCD 패널 검사장비용 LED 광엔진 시제품 설계 및 제작

류장렬(Jang-Ryeol Ryu),이부형(Boo-Hyung Lee),박현상(Hyun-Sang Park),이구열(Gu-Yuol Lee) 한국정보기술학회 2009 한국정보기술학회논문지 Vol.7 No.6

LEDs are using widely in field of illumination, optical source of inspection instrument and LCD backlight because they have several merits such as low power consumption, long lifetime, high brightness ratio, fast response, environment friendly. For using them as an optical source of inspections equipment for LCD panel, the design of excellent optical engine havings, brightness uniformity and high power and good protection against heat is essential. In this paper, two optical engine prototypes which is built in the large size LCD backlight by LED array structure were designed and developed. After that, their performances were measured. The final selected optical engine prototype was what has Type Ⅱ LED array structure It showed the luminous intensity uniformity of 101%, luminous intensity of 236% and temperature of 150% over target values.

Detection of Facial Feature Regionsby Manipulation of DCT’s Coefficients

이부형(Lee, Boo-Hyung),류장렬(Ryu, Jang-Ryeol) 한국산학기술학회 2007 한국산학기술학회논문지 Vol.8 No.2

본 논문에서는 DCT계수의 특성을 이용하여 조명조건이나 얼굴의 크기에 무관하게 얼굴특정영역을 검출하기 위한 새로운 방법을 제안한다. 일반적으로 영상을 DCT변환하면 영상의 에너지가 저주파영역에 집중되는 특성을 가지나 얼굴 특정요소들은 얼굴영상에서 비교적 고주파 성분들을 포함하고 있기 때문에 저주파에 해당되는 DCT계수들의 일부를 제거한 후 역변환을 취하면 얼굴특징영역이 강조된 영상을 얻을 수 있다. 따라서, 본 논문에서는 DCT변환된 영상으로부터 저주파 계수의 일부를 제거하여 얼굴특징요소 후보들을 추출한 후 템플릿을 적용하여 얼굴특정요소 영역을 결정한다. 얼굴특정요소 영역이 결정되면 얼굴특정요소 추출 알고리즘을 적용하여 눈, 코, 업을 구별한다. 제안된 알고리즘을 MIT의CBCL DB와 Yale facedatabase B 에 적용하여 실험하였다. 실험결과 DCT변환된 영상에서 저주파 일부의 계수를 제거한 후 얼굴 특정영역을 검출했을 경우 그렇지 않은 영상보다 영상의 크기와 조명조건의 변화에 무관하게 인식성능이 향상됨을 알 수 있었다. This paper proposes a new approach for the detection of facial feature regions using the characteristic of DCT(discrete cosine transformation) thatconcentrates the energy of an image into lower frequency coefficients. Since the facial features are pertained to relatively high frequency in a face image, the inverse DCT after removing the DCT’s coefficients corresponding to the lower frequencies generates the image where the facial feature regions are emphasized. Thus the facial regions can be easily segmentedfrom the inversed image using any differential operator. In the segmented region, facial features can be found using face template The proposedalgorithm has been tested with the image MIT’s CBCL DB and the Yale facedatabase B. The experimental results have shown superior performance under the variations of image size and lighting condition.

LDPE/EVA B Lend의 난연성 및 전기/기계적 특성

류부형 ( Boo Hyung Ryu ),이청 ( Chung Lee ),김기엽 ( Ki Yup Kim ) 한국안전학회 2008 한국안전학회지 Vol.23 No.4

Flame Retardancy and Electrical/Mechanical Properties of LDPF/EVA Blend

류부형,이청,김기엽,Ryu, Boo-Hyung,Lee, Chung,Kim, Ki-Yup The Korean Society of Safety 2008 한국안전학회지 Vol.23 No.4

In this research, magnesium hydroxide as a flame retardant agents and zinc borate as a synergist were mixed with LDPF/EVA blended samples, in order to improve their flame retardancy. We attempted to select the best mixing ratio of the LDPF/EVA blend and the optimum amount of magnesium hydroxide and zinc borate by the comparison and analysis of the flame retardancy, the electrical properties such as the volume resistivity and dielectric loss tangent, and the mechanical properties such as the tensile strength and elongation at break. Particularly, specimen which is the 6phr of zinc borate and 10phr of magnesium hydroxide 70/30phr adding to the LDPF/EVA blended samples has been most excellent in flame retardancy and electrical/mechanical properties. 본 연구에서는 저밀도 폴리에틸렌과 에털렌 비닐 아세테이트 블렌드(LDPF/EVA)의 난연성을 향상시키기 위해 난연제인 수산화 마그네슘과 난연상승보조제인 zinc borate를 첨가한 후, 난연성과 체적저항률, 유전정접, 교류 절연파괴강도 등의 전기적 특성, 인장강도 및 연신율 등의 가계적 특성을 비교 분석하여 가장 우수한 LDPF/EVA 블렌드의 혼합비 및 적절한 $Mg(OH)_2$의 zinc borate의 첨가량을 선정하고자 하였다. 혼합비 70/30phr의 LDPF/EVA 블렌드에 10phr의 $Mg(OH)_2$와 6phr 정도의 zinc borate를 첨가한 시편에서 가장 우수한 난연성 및 전기/기계적 특성을 나타내었다.

Effects of Antioxidants on Mechanical and Electrical Properties of Co⁶⁰-γ Ray Irradiated EPDM

柳富衡(Boo-Hyung Ryu),金基燁(Ki-Yup Kim) 대한전기학회 1998 전기학회논문지 Vol.47 No.8

대면적 LCD 백라이트용 LED 배열 구조의 시제품 제작 및 성능 분석

이부형(Boo-Hyung Lee),류장렬(Jang-Ryul Ryu) 한국정보기술학회 2009 Proceedings of KIIT Conference Vol.2009 No.-

본 논문에서는 적은 열발생, 양호한 광량 및 광균일도를 얻을 수 있는 대면적 LCD BLU 용 LED 배열구조로 거리가 조절된 등간격 배열의 구조(LED Array Type 12)를 선택하여 시제품을 제작한 후 시제품의 광균일도, 조도, 온도를 측정하였다. 측정결과 목표대비 101%의 광균일도, 236%의 조도, 150%의 온도를 얻을 수 있어 양호한 결과를 입증하였다. In This paper, the LED Array prototype for using in Large area LCD BLU is designed and its performances are measured. LED array prototype have LEDs which are arranged with equal distances but the narrowest gaps.(LED Array type 12). It is showed that The LED array prototype which is designed in this paper have the luminous intensity uniformity of 101% , luminous intensity of 236% and temperature of 150% over target values.

Back Light Unit 내부의 LED Back light의 광균일도를 향상시키기 위한 LED 배열 방식의 비교 분석

류장렬(Jang-Ryul Ryu),이부형(Boo-Hyung Lee),이구열(Gu-yeol Lee) 한국정보기술학회 2009 한국정보기술학회논문지 Vol.7 No.1

This paper presents various LED array methods to improve the luminous Intensity uniformity of LED Back Light in BLU for LCD Probe Station, and especially LED array methods applicable to the LED BLU over 22 inch requiring a great quantity of LEDs(16,000-20,000) are represented. The presented LED array methods consist of two types of equal-distance array architectures (Type11/Type12) and two types of non equal-distance array architectures (Type21/Type22). Basically, Type11 and Type12 have LEDs which are arranged with equal distances but the narrowest gaps. However, Type 21 and Type 22 have LEDs which are arranged with non-equal distance. In Type 21 and Type 22, gaps between LEDs in central part and gaps between LEDs in non-central part are different. Especially, in Type22, gaps between LEDs in non-central part change many times. LED array methods presented in this paper were all simulated by the LightTools. As a simulation result, All four types showed a good luminous Intensity uniformity over 85% and especially Type21 and Type 22 showed a good luminous Intensity uniformity over 88%.

고휘도 Line LED조명시스템(HLLLI)설계 및 개발

류장렬(Jang-Ryul Ryu),이부형(Boo-Hyung Lee) 한국정보기술학회 2008 한국정보기술학회논문지 Vol.6 No.5

In this paper, HLLLI(High Luninous Line LED Illuminator) system which use the high luminous LEDs and is applicable to Line AIO(Auto Optical Inspector) is manufactured for installation on a large size LCD inspection process line. The performance tartget of the HLLLI system has been set at light line length over 600mm, light width within 5mm, luminous intensity over 150,000 Lux. The HLLLI system was tested by LightTool and a Luminous intensity measurement tool and target of the system performance was achieved consequently.