• Title/Summary/Keyword: LCDs

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Scene-adaptive RGBW conversion algorithms for RGBW LCDs

  • Baek, H.I.;Kwon, K.J.;Sohn, H.H.;Seo, C.R.;Chung, I.J.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2005.07b
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    • pp.1592-1594
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    • 2005
  • LCDs with an additional white sub-pixel (RGBW LCDs) have been developed mainly to achieve higher panel transmittance. However this RGBW pixel structure causes the perceptual color difference between RGBW and RGB LCDs due to decreased primary color luminance. To solve this problem, we proposed and developed RGBW conversion algorithms that function adaptively as a displayed image changes. The test results show that the perceptual color difference could be solved to some degree by applying these new algorithms.

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Flexible Display i Low Temperature Processes for Plastic LCDs

  • Han, Jeong-In
    • Transactions on Electrical and Electronic Materials
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    • v.4 no.2
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    • pp.10-14
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    • 2003
  • Flexible displays such as plastic-based liquid crystal displays (LCDs) and organic light-emitting diode displays (OLEDDs) have been researched and developed at KETI since 1997. The plastic film substrate is very weak to heat and pressure compared to glass substrate, that its fabrication process is limited to 110$^{\circ}C$ and low pressure. The ITO films were deposited on the bare plastic film substrate by rf-magnetron sputtering. Moreover, in order to maintain uniform cell gap and pressure on the plastic film substrate, we utilized newly-invented jig and fabrication process. Electro-optical characteristics were better than or equivalent to those of typical glass LCDs though it is thinner, lighter-weight, and more robust than glass LCDs.

Novel Optical Design of Light-Guide Plates for Transflective Liquid Crystal Displays.

  • Park, Won-Sang;Park, Kwang-Il;Han, Kwan-Young;Yoon, Tae-Hoon;Kim, Jae-Chang
    • 한국정보디스플레이학회:학술대회논문집
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    • 2002.08a
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    • pp.880-882
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    • 2002
  • We have proposed a novel optical design technique of light-guide plates(LGPs) which can able to improve the optical efficiency of transflective LCDs. The basic concepts of our design technique are that we make the groove-pattern of LGP pixels resemble the pixel-array-pattern of transflective LCDs in shape and size and make the surface of the groove scatter (front scattering). In simulated and measured results, we ensure that our design of LGP in backlight unit for transflective LCDs can improve the optical efficiency of LCDs.

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The viewing angle switching of TN-LCD with two tilted LC layer (기울어진 두 액정 층을 이용한 비틀린 네마틱 액정 셀의 시야각 조절)

  • Choi, Min-Oh;Lim, Young-Jin;Jeong, Eun;Lee, Seung-Hee
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2006.04a
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    • pp.45-46
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    • 2006
  • We have studied the viewing angle control using a twist nematic liquid crystal display (TN-LCDs). These TK-LCDs have the characteristics, of which is not good image quality, for examples low Contrast ratio and gray scale inversion problems at upper and down viewing direction. TN-LCDs have the function of switching between the wide viewing mode and narrow viewing angle mode using two tilted LC layers. Tilt angles of the two LC layers, $14^{\circ}$ and $60^{\circ}$ were required in both wide viewing angle and narrow viewing angle modes, respectively. Consequently, this device is compatible with two image performances of which the wide viewing angle mode and Narrow viewing angle mode.

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Effect of Different GC Columns on the Quantitative Analysis of Long Chain Alkyl Diols (LCDs) (특성이 다른 GC 컬럼이 long chain alkyl diols (LCDs)의 정량 분석에 미치는 영향)

  • GAL, JONG-KU;KIM, JUNG-HYUN;NAM, SEUNG-IL;SHIN, KYUNG-HOON
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.22 no.2
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    • pp.45-55
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    • 2017
  • Long chain alkyl diols (LCDs) have been reported in sediments from various marine environments. Rampen et al. (2012) introduced the paleo-sea surface temperature (SST) proxy, Long chain Diol Index (LDI) based on the relative abundance of $C_{30}$ 1,15-diol, $C_{28}$ 1,13-diol, and $C_{30}$ 1,13-diol. In general, CP-Sil5CB and DB-5ms columns have been used for the quantitative and qualitative analysis of LCDs with a GC-MS. In this study, we examined the effect of three different columns (CP-Sil5CB, HP-5ms and DB-5) on the quantitative analysis of LCDs using marine sediments from the East Sea of Korea and the western Arctic Ocean. In general, our study showed that the results of CP-Sil5CB differed significantly from those of HP-5ms and DB-5. However, the differences of the LDI-derived SSTs among three columns were $0.1-0.2^{\circ}C$ for the East Sea and $0.2-0.7^{\circ}C$ for the western Arctic Ocean, which were well within the calibration error range (${\pm}1{\sigma}$). Accordingly, our study showed that the use of different columns resulted in significant differences of LCDs concentrations, but its effect on the LDI was relatively insignificant. Therefore, it appears that the different columns can be used for the paleo-SST reconstruction in the East Sea and the western Arctic Ocean using the LDI proxy.

Optimization of the surface structure of reflector for reflective LCDs (반사형 LCD용 반사판의 표면구조의 최적화)

  • 김홍철;박원상;황용석;윤태훈;김재창
    • Korean Journal of Optics and Photonics
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    • v.13 no.2
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    • pp.166-170
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    • 2002
  • Reflectors for reflective LCDs must be designed to be able to control the direction of the image and the viewing angle range for optimal display. In this paper, we tried to optimize the reflector for reflective LCDs. The conventional surface structures showed many defects and problems. Therefore we made efforts to improve the surface structures of the conventional reflectors through both a theoretical approach and analytic work. As a result, we proposed surface structures which showed almost uniform reflectance within the viewing angle range specified by a user even at any oblique incidence. By using Beckmann's equations, we could check the reflective property of the proposed surface structures.

Flexible Display ; Low Temperature Processes for Plastic LCDs

  • Han, Jeong-In
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.07a
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    • pp.185-189
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    • 2002
  • Flexible displays such as plastic based LCDs and organic light-emitting diodes for mobile communication devices have been researched and developed at KETI in KOREA since 1997. The Plastic film substrate has so poor thermal tolerance and non-rigidness that the fabrication of active devices and panel assembly have to perform at low temperature and pressure. In addition, high thermal expansion of the substrate is also a serious problem for reliable metallic film deposition. In this paper, we investigated particularly on the fundamental characteristics of various plastic substrates and then, suggested novel methods that improve the fabrication processes of plastic LCD panel. In order to maintain stable substrate surface and uniform cell gap during panel assembly, we utilized newly-invented iii and vacuum chuck. Electro-optical characteristics of fabricated plastic LCD are better than or equivalent to those of typical glass based LCDs though it is thinner, lighter-weight and more robust.

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A New Evaluation Method of Reflective LCDs

  • Byun, Jin-Seob;Nam, Seok-Hyun;Park, Gi-Chang;Ju, Jin-Ho;Kim, Jang-Sub;Kang, Sung-Chul
    • 한국정보디스플레이학회:학술대회논문집
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    • 2002.08a
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    • pp.852-855
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    • 2002
  • Quality of the reflective LCD as a display is strongly influenced by the environment where the display is evaluated. Up to now, several methods for the evaluation of the reflective LCDs have been proposed. We have developed a new method in which the optical characteristics of the reflective LCDs from the spot light and the diffuse light can be obtained at the same time. The results obtained in our experiments by using the new method showed a good agreement with those evaluated at office and outdoor environments.

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Development of a Chip Bonding Technology for Plastic Film LCDs

  • Park, S.K.;Han, J.I.;Kim, W.K.;Kwak, M.K.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2000.01a
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    • pp.89-90
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    • 2000
  • A new technology realizing interconnection between Plastic Film LCDs panel and a driving circuit was developed under the processing condition of low temperature and pressure with ACFs developed for Plastic Film LCDs. The conduction failure of interconnection of the two resulted from elasticity, low thermal resistance and high thermal expansion of plastic substrates. Conductive particles with elasticity similar to the plastic substrate did not damaged a ITO electrode on plastic substrates, and low temperature and pressure process also did not deform the surface of plastic substrates. As a result highly reliable interconnection with minimum contact resistance was accomplished.

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