• Title/Summary/Keyword: Brightness Uniformity

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Automated classification of display defects based on imaging colorimeter measurements

  • Kostal, Hubert;Pedeville, Gary;Rykowski, Ronald;Skelly, Sean
    • 한국정보디스플레이학회:학술대회논문집
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    • 2009.10a
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    • pp.1261-1264
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    • 2009
  • The use of imaging colorimeter systems and associated analytical software to assess display brightness and color uniformity, contrast, and to identify defects is well established. In this paper we describe recent work to extend these methods to classify defects based on human visual perception.

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Using Natural Graphite Heat Spreaders to Increase CCFL LCD Operating Temperatures

  • Norley, Julian;Shives, Gary D.;Reis, Brad;Schober, John
    • 한국정보디스플레이학회:학술대회논문집
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    • 2007.08a
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    • pp.273-276
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    • 2007
  • A natural graphite heat spreader increased the upper operating temperature limit of a CCFL backlit LCD television. A 0-80W heat source was used to simulate additional electronics. Without the heat spreader, internal circuitry shut-down at ${\sim}30;$ no shut-down occurred above 80W with a heat spreader. Additionally, brightness, temperature uniformity, and operating ranges were improved, verified by environmental chamber performance testing at various ambient conditions.

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A Study on the Development of Pattern Design Tool for CCFL Backlight (CCFL 백라이트 패턴 설계툴 개발에 관한 연구)

  • Cho Young-Chang;Choi Byung-Jin;Yoon Jeong-Oh
    • Journal of Korea Society of Industrial Information Systems
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    • v.11 no.2
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    • pp.79-85
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    • 2006
  • As the portable information appliance is developed, the demand of flat panel display equipments and parts are steeply increased. Most of all, the applications of LCD such as LCD TV, monitor, digital camera, CNS(car navigation system) and game machine become diversified. With the result that the number of BLU production enterprise is increased and the research on the design of backlight with the superior optical properties is persistently in progress. In this study we developed the pattern design tools for CCFL(cold cathode flourescent lamp) backlight to improve the conventional pattern design environment in which the pattern is designed manually from the experience and the trial and error. For the verification of our research, we designed the light reflection surface patterns for a real model of backlight and we measured the brightness uniformity using the BM-7. From the brightness uniformity measurement, the BLU designed using the presented tool showed the tolerable performance only in the first try of pattern design rather than the fifth try of pattern design in case of the conventional pattern design.

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Image Analysis of Diffuse Liver Disease using Computer-Adided Diagnosis in the Liver US Image (간 초음파영상에서 컴퓨터보조진단을 이용한 미만성 간질환의 영상분석)

  • Lee, Jinsoo;Kim, Changsoo
    • Journal of the Korean Society of Radiology
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    • v.9 no.4
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    • pp.227-234
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    • 2015
  • In this paper, we studied possibility about application for CAD on diffuse liver disease through pixel texture analysis parameters(average gray level, skewness, entropy) which based statistical property brightness histogram and image analysis using brightness difference liver and kidney parenchyma. The experiment was set by ROI ($50{\times}50$ pixels) on liver ultrasound images.(non specific, fatty liver, liver cirrhosis) then, evaluated disease recognition rates using 4 types pixel texture analysis parameters and brightness gap liver and kidney parenchyma. As a results, disease recognition rates which contained average brightness, skewness, uniformity, entropy was scored 100%~96%, they were high. In brightness gap between liver and kidney parenchyma, non specific was $-1.129{\pm}12.410$ fatty liver was $33.182{\pm}11.826$, these were shown significantly difference, but liver cirrhosis was $-1.668{\pm}10.081$, that was somewhat small difference with non specific case. Consequently, pixel texture analysis parameter which scored high disease recognition rates and CAD which used brightness difference of parenchyma are very useful for detecting diffuse liver disease as well as these are possible to use clinical technique and minimize reading miss. Also, it helps to suggest correct diagnose and treatment.

Flat Fluorescent Lamp(FFL) and Analysis of Optical Efficiency of FFL Lighting (면광원 램프 및 이를 이용한 조명 기기의 효율 특성 연구)

  • Park, Jong-Lee;Lim, Sung-Kyoo
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.21 no.7
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    • pp.6-12
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    • 2007
  • A flat fluorescent lamp (FFL) developed as a light source for LCD TV backlight was used as a light source for general lighting application and its electro-optical characteristics were measured and evaluated. The channels of FFL were formed from a flat glass at high temperature by using a mold. The performance of FFL with lighting future was shown to improve by optimizing the channel profile of FFL. In this paper, the brightness efficiency of FFL with lighting fixture was evaluated and compared with that of the hot cathode fluorescent lamp (HCFL), the major light source for general lighting. The optical efficiency of FFL with future was shown to be 72.7[1m/W].

Subjective Imaging Effect Assessment for Intelligent Imaging Terminal Design: a Method for Engineering Site

  • Liu, Haoting;Lv, Ming;Yu, Weiqun;Guo, Zhenhui;Li, Xin
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.14 no.3
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    • pp.1043-1064
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    • 2020
  • A kind of Subjective Imaging Effect Assessment (SIEA) method and its applications on intelligent imaging terminal design in engineering site are presented. First, some visual assessment indices are used to characterize the imaging effect: the image brightness, the image brightness uniformity, the color image contrast, the image edge blur, the image color difference, the image saturation, the image noise, and the integrated imaging effect index. A linear weighted function is employed to carry out the SIEA computation and the Analytic Hierarchy Process (AHP) technique is used to estimate its weights. Second, a SIEA software is developed. It can play images after the settings of assessment index or assessment reaction time, etc. Third, two cases are used to illustrate the application effects of proposed method: the image enhancement system design for surveillance camera and the imaging environment perception system design for intelligent lighting terminal. A Prior Sequential Stimulus (PSS) experiment is proposed to improve the evaluation stability of SIEA method. Many experiment results have shown the proposed method can realize a stable system design or parameters setting for the intelligent imaging terminal in engineering site.

Sensory and Microbial Characteristics of a Rice Processed Snack using Sweet Pumpkin Powder for Infants (단호박 분말 첨가 영아용 쌀 가공 스낵의 관능적 미생물적 품질 특성)

  • Kim, Eunkyung;Wu, Xiubao;Choi, Kunyoung;Kim, Haeyoung
    • Journal of the Korean Society of Food Culture
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    • v.33 no.3
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    • pp.261-267
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    • 2018
  • The sensory characteristics of a rice processed snack for 6 to 12 month old infants were investigated. The microbiological safety of all samples was also tested. The moisture content of snack of the SW snack was 6.33 significantly higher than in the other snacks (p<0.05). The sensory intensities of RW were highest in glossiness brightness, uniformity, sweet aroma, savory flavor, sweet flavor, chewiness and crispiness. In the; consumer acceptance test, RW showed significantly higher glossiness, uniformity, sweet aroma, savory flavor, sweet flavor, rancid, chewiness, adhesiveness, crispiness and overall acceptance than the other snacks (p<0.05). The aerobic plate counts were negative in all the samples tested. E. coli and pathogenic microorganisms tests were also negative or not detected, showing that all the samples tested were microbiologically safe according to the food code which applies to food manufacturers. Overall, potentially high value products of rice processed snacks for 6 to 12 month old infants were developed and tested They are expected to be utilized and in the competitive and growing infant food industry.

Comparison of Optical Characteristics between CCFL and EEFL in Direct-type Backlight Unit

  • Han, Jeong-Min;Han, Jin-Woo;Seo, Dae-Shik
    • Transactions on Electrical and Electronic Materials
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    • v.8 no.6
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    • pp.268-273
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    • 2007
  • In this study, It was studied about the luminance characteristics of 17 inch direct-type back light using EEFL(external electrode fluorescent lamp) and CCFL(cold cathode fluorescent lamp). The EEFL has a long life time because the electrode is installed outside of lamp. And it is produced in lower price than conventional CCFL. Moreover, it does not need process of installing internal electrode. However, the EEFL technology has several problems such as difficulty of designing driving inverter and preventing this phenomenon along the skin of lamps. We suggested two types of backlight unit for LCD TV application using the EEFL and the CCFL. We found optimized optical design parameters. We set the optical variation parameters such as lamp height, lamp distance, total thickness, and angles of inner walls. We achieved 7580 nits of center luminance, 82% of luminance uniformity by using 20 lamps of the EEFL and 7297 nits of center luminance, 78% of luminance uniformity by using 16 lamps of the CCFL.

Effect of Stabilizers on Performance of Electroluminescence Display Device (안정화제가 무기 전계발광 디스플레이 소자 성능에 미치는 영향)

  • Shin, DongHyuk;Lim, JongChoo
    • Korean Chemical Engineering Research
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    • v.45 no.4
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    • pp.356-363
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    • 2007
  • The stability of paste solutions for electroluminescence display(ELD) device was found to be greatly affected by kind and dosage of a stabilizer used. The stabilizer Disperbyk-180 showed the best stability performance against phosphor paste solutions among the stabilizers used during this study. The phosphor paste solutions remained stable over 90 days with a wide range of added amounts of Disperbyk-180. Based on the above results, screen printing test was performed. The addition of Disperbyk-180 into phosphor and dielectric paste solutions produced improved qualities such as no phase separation, no bubble generation and no significant viscosity change during printing process. Especially for the phosphor paste solution, both uniformity and brightness were significantly improved and the excellent adhesion onto the ITO film was found. The ELD device fabricated using the above same paste solutions showed brightness of $57.6cd/m^2$ at 100V and 400 Hz. The half lifetime of ELD device was measured as 1,250 hours and almost the same value observed with imported commercial paste solutions.

Design of the Lens Structure for COB type LED Safety Luminaires (COB형 LED 보안등을 위한 렌즈 구조 설계)

  • Jang, Sung-Whan;Jung, Byoung-Jo
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.27 no.8
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    • pp.1-8
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    • 2013
  • The study carried out in this dissertation focuses on the lens structure design and the light distribution for LED safety luminaires using COB type LED module. Lens structures for LED lights has been designed 1) to induce light diffusion by dual process of internal reflection and refraction, 2) to minimize the inherent LED lights' glittering, and 3) to have uniform brightness. The lens designed with the proposed structures function as diffusers for the divergence of the LED lights so that they form a wide angle of view and adjust the light distribution. We designed of lens with stable uniformity factor and average roughness using aspheric optics property. Finally we made the analysis data of the simulated data.