• Title/Summary/Keyword: Light guide film

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Evaluation of luminance performance of scintillating film for monitoring the position of a radioactive source in an NDT apparatus (비파괴검사 장치 내 방사선원 위치감시용 섬광필름의 발광성능 평가)

  • Lee, Kyung-Jin;Yun, Jeong-Ick;Park, Byung-Gi;Kim, Sin;Lee, Bong-Soo
    • Journal of radiological science and technology
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    • v.28 no.1
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    • pp.13-17
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    • 2005
  • In domestic nondestructive testing(NDT) field, there have recently been radiation exposure accidents due to a disregard for confirmation of the position of radioisotope during the test. In order to prevent these kinds of accidents, a scintillating film has been developed. The scintillating film that can convert gamma-ray to visible light has a function of the position detection of radioisotope in a opaque guide tube of an NDT apparatus. The aim of this study is to enhance the visibility performance of the scintillating film and find out the best configuration of the scintillating film. In order to find appropriate materials for the scintillating film, various inorganic scintillating materials were evaluated in this work. An absolute luminance of the scintillating films was measured by luminance meter for evaluation of visibility performance. Ir-192 gamma projector was used for NDT apparatus. The experiment shows that the scintillating film with reflective layer was the more effective performance for visibility. The higher mixing ratio of scintillating material to binding material, the higher luminance was measured. $Gd_2O_2S(Tb)$ inorganic powder as the scintillating materials had the best performance for visibility of the scintillating film. The developed scintillating film helps to ensure safer environment to the operators.

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Optimization of Optical Structure of Lightguide Panel for Uniformity Improvement of Edge-lit Backlight (엣지형 LED 백라이트의 균일도 향상을 위한 도광판의 광구조 최적화)

  • Lee, Jung-Ho;Nahm, Kie-Bong;Ko, Jae-Hyeon;Kim, Joong-Hyun
    • Korean Journal of Optics and Photonics
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    • v.21 no.2
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    • pp.61-68
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    • 2010
  • Optical simulation methods were applied to the edge-lit LED backlight for LCD TV applications in order to optimize the optical structure of the light guide plate(LGP), and thus to improve the uniformity properties by removing the bright spots caused by LED's. The edge-lit LED backlight consisted of three white LED's with a lamp cover, a light guide plate, and a reflection film. When there was no pattern on the entrance side surface of the LGP, the illuminance uniformity was sensitively dependent on the distance d between the LED and the entrance surface. The illuminance uniformity increased with d but its increasing rate slowed down when d was beyond ~ 1.5 mm. When micro-patterns such as a lenticular lens array (LLA) or a serration pattern were formed on the entrance surface, the illuminance uniformity was improved substantially even for the case of very small d. At the same simulation condition, the lightguide with serration pattern showed a better uniformity than that with LLA pattern. Additional improvement could be achieved by changing the refractive index of the micro-patterns. These results suggest that using micro-patterns is a very effective way to reduce the bright spots due to their refracting function for the concentrated incident rays onto the LGP.

Study on the Simulation Model for the Optimization of Optical Structures of Edge-lit Backlight for LCD Applications

  • Ju, Young-Hyun;Park, Ji-Hee;Lee, Jeong-Ho;Lee, Ji-Young;Nahm, Kie-Bong;Ko, Jae-Hyeon;Kim, Joong-Hyun
    • Journal of the Optical Society of Korea
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    • v.12 no.1
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    • pp.25-30
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    • 2008
  • The optical performances of 15-inch edge-lit backlight were simulated by using a Monte Carlo ray-tracing technique. The backlight model was built by combining a wedge-type light guide plate, a diffuser sheet, a tubular fluorescent lamp with a lamp reflector, and two crossed prism sheets. Angular distributions of the luminance on each optical component obtained from simulation were consistent with those obtained from experiments on a real 15-inch backlight. The constructed backlight model was used to evaluate the optical performances of a micro-pyramid film. It was found that the on-axis luminance gain on the pyramid film is higher than that on one prism film but much lower than that on the two crossed prism films. These results suggest that a reliable simulation model can be used to develop new hybrid films and to optimize the optical structure of edge-lit backlight in order to reduce the developmental period.

Deposition of SiO2 Thin Film for the Core of Planar Light-Wave-Guide by Transformer Coupled Plasma Chemical-Vapor-Deposition (TCP-CVD 장비를 활용한 광도파로용 Core-SiO2 증착)

  • Kim, Chang-Jo;Shin, Paik-Kyun
    • Journal of the Korean Vacuum Society
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    • v.19 no.3
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    • pp.230-235
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    • 2010
  • In this paper, we controlled the deposition rate and reflective index with process conditions that are TCP power, gas flow ratio and bias for optical properties of $SiO_2$ thin film using TCP-CVD equipment. We obtained a excellent $SiO_2$ thin film which has a excellent uniformity (<1 [%]), deposition rate (0.28 [${\mu}m$/ min]) and reflective index (1.4610-1.4621) within 4" wafer with process conditions ($SiH_4:O_2$=50 : 100 [sccm], TCP power 1 [kW], bias 200 [W]) at [$300^{\circ}C$].

A study on the fabrication method of middle size LGP using continuous micro-lenses made by LIGA reflow

  • Kim, Jong-Sun;Ko, Young-Bae;Hwang, Chul-Jin;Kim, Jong-Deok;Yoon, Kyung-Hwan
    • Korea-Australia Rheology Journal
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    • v.19 no.3
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    • pp.171-176
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    • 2007
  • LCD-BLU (Liquid Crystal Display-Back Light Unit) of medium size is usually manufactured by forming numerous dots with $50{\sim}300\;{\mu}m$ in diameter by etching process and V-grove shape with $50\;{\mu}m$ in height by mechanical cutting process. However, the surface of the etched dots is very rough due to the characteristics of the etching process and V-cutting needs rather high cost. Instead of existing optical pattern made by etching and mechanical cutting, 3-dimensional continuous micro-lens of $200\;{\mu}m$ in diameter was applied in the present study. The continuous micro-lens pattern fabricated by modified LIGA with thermal reflow process was tested to this new optical design of LGP. The manufacturing process using LIGA-reflow is made up of three stages as follows: (i) the stage of lithography, (ii) the stage of thermal reflow process and (iii) the stage of electroplating. The continuous micro-lens patterned LGP was fabricated with injection molding and its test results showed the possibility of commercial use in the future.

The Study of Prism-Patternde Light Guide Plate for increase of efficiency in Monitor Back Light Unit (MNT BLU의 효율 향상을 위한 프리즘 도광판에 대한 연구)

  • Park, Doo-Sung;Lee, Mi-Sun;Park, Ki-Duck;Oh, Young-Sik;Kim, Seo-Yoon;Lim, Young-Jin
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2005.07a
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    • pp.502-503
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    • 2005
  • 본 연구에서는 TFT-LCD(Thin Film Transistor-Liquid Crystal Display)의 배경광원인 BLU(Back Light Unit)의 고효율화, 고품질화를 통한 원가 절감을 달성하기 위해 BLU의 대표적 핵심부품중에 하나인 프리즘 시트를 사용하지 않는 구조의 MNT용 BLU를 개발하는데 목적을 두었다. 고효율의 BLU를 만들기위하여 17인치 BLU의 도광판의 상, 하면에 Prism 형상을 구현하였으며, 광학적 시뮬레이션을 통하여 먼저 가능성을 검토하였고, UV에 반응하는 Resin을 경화시키는 방법을 이용하여 일반 도광판에 프리즘형상을 각인(Imprint)시키는 방법으로 실물을 재현하였다. 실험 결과 프리즘 시트를 사용하지 않는 구조의 MNT용 17인치 BLU에서 중심휘도 4,984nit, 균일도 70% 달성하였다.

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Extreme baking effect of interlayer on PLED's performance

  • Kim, Mu-Gyeom;Kim, Sang-Yeol;Lee, Tae-Woo;Park, Sang-Hun;Park, Jong-Jin;Pu, Lyong-Sun
    • 한국정보디스플레이학회:학술대회논문집
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    • 2006.08a
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    • pp.1775-1778
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    • 2006
  • Through baking process on an interlayer, known as hole transporting layer, varying baking temperature up to 300 degree, which is considered as extremely high for polymer light emitting device (PLED) system, we found interesting relationship between packing density and morphology affecting device performance. Granular morphology shows that as temperature increases, grain size is getting smaller to pack closely and make interlayer harden. Such denser interlayer has temperature dependency of its own mobility, even without clear evidence of degradation of material itself. Its fact proven in a single film also reflects on multilayered PLED's performance like IVL, efficiency, lifetime. It's found that, especially, to enhance lifetime is related with thermal stability of interlayer and its mobility dependency to meet better charge balance. Therefore, it gives us understanding not only baking effect of interlayer, but also material & device designing guide to enhance lifetime.

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Analysis on Optical Characteristics of LCD Backlight LGP (LCD 백라이트 도광판의 광학 특성에 대한 연구)

  • Sah, Jong-Youb;Park, Jong-Ryul
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.28 no.4
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    • pp.362-369
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    • 2004
  • LGP(Light-Guide Panel) of LCD backlight is one of the major componets which affect on the product quality of LCD. The optical relation between brightness and pattern has been investigated for LGP with the uniform distribution of brightness. When given the brightness distribution as target, the solutions of pattern distribution is not unique. Each solution of pattern designs shows the different brightness intensity even though they have the same brightness distribution with target's one. The manufacturing condition of pattern has an influence on the possibly-maximum-brightness intensity among the solutions of pattern design. The present study has examined the effects of LGP thickness, pattern shape errors, and reflection film on the optical characteristics of LGP.

Electrical, Electronic Structure and Optical Properties of Undoped and Na-doped NiO Thin Films

  • Denny, Yus Rama;Lee, Kangil;Seo, Soonjoo;Oh, Suhk Kun;Kang, Hee Jae;Yang, Dong-Seok
    • Proceedings of the Korean Vacuum Society Conference
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    • 2014.02a
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    • pp.193.1-193.1
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    • 2014
  • This study was to investigate the electronic structure and optical properties of Na doped into NiO thin film using XPS and REELS. The films were grown by electron beam evaporation with varying the annealing temperature. The relationship between the electrical characteristics with the local structure of NiO thin films was also discussed. The x-ray photoelectron results showed that the Ni 2p spectra for all films consist of Ni 2p3/2 which indicate the presence of Ni-O bond from NiO phase and for the annealed film at temperature above $200^{\circ}C$ shows the coexist Ni oxide and Ni metal phase. The reflection electron energy loss spectroscopy spectra showed that the band gaps of the NiO thin films were slightly decreased with Na-doped into films. The Na-doped NiO showed relatively low resistivity compared to the undoped NiO thin films. In addition, the Na-doped NiO thin films deposited at room temperature showed the best properties, such as a p-type semiconducting with low electrical resistivity of $11.57{\Omega}.cm$ and high optical transmittance of ~80% in the visible light region. These results indicate that the Na doping followed by annealing process plays a crucial in enhancing the electrical and optical properties of NiO thin films. We believe that our results can be a good guide for those growing NiO thin films with the purpose of device applications, which require deposited at room temperature.

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Deconstructive reading of Makoto Shinkai's : Stories of things that cannot meet without their names (해체로 읽는 신카이 마코토의 <너의 이름은. 군(君)の명(名)は.> : 이름 없이는 서로 만날 수 없는 사물들에 대해)

  • Ahn, Yoon-kyung;Kim, Hyun-suk
    • Cartoon and Animation Studies
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    • s.50
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    • pp.75-99
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    • 2018
  • Makoto Shinkai, an animated film maker in Japan, has been featured as a one-person production system and as a 'writer of light', but his 2016 release of "Your Name" was a departure from the elements that characterize his existing works. At the same time, by the combination of the traditional musubi(むすび) story, ending these, it was a big hit due to its rich narratives and attraction of open interpretation possibility. As it can be guessed from the title of this work, this work shows the encounter between the Japanese ancient language and the modern language in relation to the 'name', and presents the image that the role of the name(language) is repeatedly emphasized with various variations in events for the perfect 'encounter'. In this work, the interpretations of $Signifi\acute{e}$ for characters and objects are extended and reserved as a metaphorical role of the similarity, depending on the meaning of the subject which they touch. The relationship between words and objects analyzed through the structure of Signifiant and $Signifi\acute{e}$ is an epoch-making ideological discovery of modern times revealed through F. Saussure. Focusing on "the difference" between being this and that from the notion of Saussure, Derrida dismissed logocentrism, rationalism that fully obeyed the order of Logos. Likewise, dismissing the center, or dismissing the owner had emerged after the exclusive and closed principle of metaphysics in the west was dismissed. Derrida's definition of 'deconstruction' is a philosophical strategy that starts with the insight on the nature of language. 'Dissemination,' a metaphor that he used as a methodological concept to read texts acts as interpretation and practice (or play), but does not pursue an ultimate interpretation. His 'undecidability' does not start with infinity, but ends with infinity. The researcher testifies himself and identifies that we can't be an interpreter of the world because we, as a human are not the subject of language but a user. Derrida also interpreted the world of things composed of Signifiant and $Signifi\acute{e}$ as open texts. In this respect, this study aimed to read Makoto's works telling about the meeting of a thing and a thing with name as a guide, based on Derrida's frame of 'deconstruction' and 'dissemination.' This study intends to re-consider which relationship the Signifiant and $Signifi\acute{e}$ have with human beings who live in modern times, examine the relationship between words and objects presented in this work through Jacques Derrida's destruction and dissemination concepts, and recognize that we are merely a part of Signifiant and $Signifi\acute{e}$. Just as Taki and Mitsuha confirm the existence by asking each other, we are in the world of things, expecting musubi that a world of names calls me.