• Title/Summary/Keyword: Thin liquid film

Search Result 532, Processing Time 0.032 seconds

Segmentation of Defective Regions based on Logical Discernment and Multiple Windows for Inspection of TFT-LCD Panels (TFT-LCD 패널 검사를 위한 지역적 분별에 기반한 결함 영역 분할 알고리즘)

  • Chung, Gun-Hee;Chung, Chang-Do;Yun, Byung-Ju;Lee, Joon-Jae;Park, Kil-Houm
    • Journal of Korea Multimedia Society
    • /
    • v.15 no.2
    • /
    • pp.204-214
    • /
    • 2012
  • This paper proposes an image segmentation for a vision-based automated defect inspection system on surface image of TFT-LCD(Thin Film Transistor Liquid Crystal Display) panels. TFT-LCD images have non-uniform brightness, which is hard to finding defective regions. Although there are several methods or proposed algorithms, it is difficult to divide the defect with high reliability because of non-uniform properties in the image. Kamel and Zhao disclosed a method which based on logical stage algorithm for segmentation of graphics and character. This method is a one of the local segmentation method that has a advantage. It is that characters and graphics are well segmented in an image which has non-uniform property. As TFT-LCD panel image has a same property, so this paper proposes new algorithm to segment regions of defects based on Kamel and Zhao's algorithm. Our algorithm has an advantage that there are a few ghost objects around the defects. We had experiments to prove performance in real TFT-LCD panel images, and comparing with the FFT(Fast Fourier Transform) method which is used a bandpass filter.

Defects analysis of RE : YAG (RE = Nd3+, Er3+) single crystal synthesized by Czochralski method (Czochralski법으로 성장된 RE : YAG(RE = Nd3+, Er3+) 단결정의 결함분석)

  • Park, Cheong Ho;Joo, Young Jun;Kim, Hye Young;Shim, Jang Bo;Kim, Cheol Jin
    • Journal of the Korean Crystal Growth and Crystal Technology
    • /
    • v.26 no.1
    • /
    • pp.1-7
    • /
    • 2016
  • RE : YAG ($RE=Nd^{3+}$, $Er^{3+}$) single crystals are laser diodes and generally grown by Czochralski method with controlling the various growth parameter. Since the defects occurred by temperature gradient or the rotation speed of solid-liquid growth interface act as the decline of crystal optical property during the growth procedure, crystalline quality improvement via defects analysis is necessary. The etch pit density (EPD) analysis was used to confirm the surface defect of grown RE : YAG single crystal and to select the area of transmission electron microscopy (TEM) analysis. Defects in the specimen produced by tripod polishing method such as buckling, rod shaped, bend contours by internal stress, segregation and others were observed by using 200 kV TEM and 300 kV FE-TEM.

Improvement of Electronic Properties and Amplification of Electron Trapping/Recovery through Liquid Crystal(LC) Passivation on Amorphous InGaZnO Thin Film Transistors

  • Lee, Seung-Hyeon;Kim, Myeong-Eon;Heo, Yeong-U;Kim, Jeong-Ju;Lee, Jun-Hyeong
    • Proceedings of the Korean Vacuum Society Conference
    • /
    • 2016.02a
    • /
    • pp.267.1-267.1
    • /
    • 2016
  • 본 연구에서는 nematic 액정의 종류 중 하나인 5CB (4-Cyano-4'-pentylbiphenyl) 물질을 박막 트랜지스터 (TFT)의 passivation 층으로 사용했을 때 그 전기적 특성향상을 확인하였다. RF-magnetron sputtering법으로 증착된 비정질 InGaZnO 박막을 활성층으로 사용한 TFT를 제작하여 그 활성층 위에 drop형식으로 passivation 하였다. 그 결과, drain current (I_DS)가 약 10배 정도 증가하고, linear region(V_D=0.5V)에서 mobility와 subthreshold slope(SS)이 각각 6.7에서 12.2, 0.3에서 0.2로 향상되는 것이 보였다. 이것은 gate bias가 인가되었을 때 freedericksz 전이를 통한 액정의 배향과 이때 형성된 dipole 형성에 의한 것으로 보이며, 이러한 LC의 배향은 편광현미경을 통하여 표면과 수직으로 배향한다는 사실을 확인 할 수 있었고 이 LC-passivation된 a-IGZO TFT의 전기적 특성의 향상에 대한 mechanism을 제시하였다. 그리고 배향한 LC가 가지는 dipole에 의해 bias stress 상황에서 독특한 electron trapping과 recovery의 증폭효과가 나타났다. V_G=+20V의 positive gate bias stress를 1000s동안 가했을 때, passivation되지 않은 a-IGZO TFT의 경우 +4V의 threshold voltage shift(${\Delta}V$_TH)가 발생되었고, 바로 -20V의 negative gate bias를 30s간 가해주었을 때 -2.5V의 ${\Delta}V$_TH가 발생하였다. 반면 LC-passivation된 a-IGZO TFT의 경우 각각 +5V와 -4V의 ${\Delta}V$_TH로 더 큰 변화를 가져왔다. 이러한 LC에 의한 electron trapping/recovery 증폭효과에 대한 model을 제시하였다.

  • PDF

RF Power Conversional System for Environment-friendly Ferrite Core Inductively Coupled Plasma Generator (환경친화형 페라이트 코어 유도결합 플라즈마 고주파 전력 변환 장치)

  • Lee, Joung-Ho;Choi, Dae-Kyu;Kim, Soo-Seok;Lee, Byoung-Kuk;Won, Chung-Yuen
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
    • /
    • v.20 no.8
    • /
    • pp.6-14
    • /
    • 2006
  • This paper is a study about a proper method of plasma generation to cleaning method and a high frequency power equipment circuit to generation of plasma that used cleaning of chamber for TFT-LCD PECVD. The high density plasma required for cleaning causes a possibility of high density plasma more than $1{\times}10^{11}[EA/cm^3]$. It apply a ferrite core of ferromagnetic body to a existing ICP form. In case of power transfer equipment on 400[kHz] high frequency to generation of plasma it makes certain a stable switching operation in condition of plasma through using a inverter form for general purpose HB. And it demonstrates the performance of power transfer equipment using methods of measurement which use a transformer of series combination the density of plasma and the rate of dissolution of $NF_3$ in condition of $A_r\;and\;NF_3$.

Surface Composition and Molecular Diffusion on the Stability of Foams Formed from Protein/Surfactant Mixtures (단백질/계면활성제 혼합계에서 기포안정성에 대한 계면조성과 분자확산)

  • Park, Sun-Yeong;Kim, Myung-Soo;Jeong, Noh-Hee;Nam, Ki-Dae
    • Journal of the Korean Applied Science and Technology
    • /
    • v.17 no.3
    • /
    • pp.158-166
    • /
    • 2000
  • A conductimetric study of foam formed from mixture of the protein, ${\beta}-lactoglobulin$, and the nonioinc surfactant, SML, revealed that their stability was reduced at concentrations of SML in the range $3{\sim}10mM$. The interaction of SML with ${\beta}-lactoglobulin$ was investigated by fluorimetry and a dissociation constant of $0.2{\mu}M$ was calculated for the complex. Surface tension studies confirmed the presence of interaction between the two components and provided evidence for the progressive displacement of ${\beta}-lactogloblin$ from the air/water interface with increasing SML concentration. Experiments using air-suspended microscopic thin liquid films revealed transitions in the chainage characteristics and thickness of the film at SML concentrations below that which resulted in destabilization of the foam. However, measurements of surface mobility of fluorescent-labeled ${\beta}-lactoglobulin$ by a photobleaching method identified that a transition to a mobile system occurred at a SML concentration which correlated with the onset of instability in the disperse phase. The results would indicate that maintenance of the viscoelastic properties of the surface is paramount importance in determining the stability of interfaces comprising mixtures of protein and surfactant.

TRIZ-based Improvement of Glass Thermal Deformation in OLED Deposition Process (트리즈 기반 OLED 증착 공정의 글래스 열 변형 개선)

  • Lee, Woo-Sung;Choi, Jin Young
    • Journal of Korean Society of Industrial and Systems Engineering
    • /
    • v.40 no.1
    • /
    • pp.114-123
    • /
    • 2017
  • The global small and mid-sized display market is changing from thin film transistor-liquid crystal display to organic light emitting diode (OLED). Reflecting these market conditions, the domestic and overseas display panel industry is making great effort to innovate OLED technology and incease productivity. However, current OLED production technology has not been able to satisfy the quality requirement levels by customers, as the market demand for OLED is becoming more and more diversified. In addition, as OLED panel production technology levels to satisfy customers' requirement become higher, product quality problems are persistently generated in OLED deposition process. These problems not only decrease the production yield but also cause a second problem of deteriorating productivity. Based on these observations, in this study, we suggest TRIZ-based improvement of defects caused by glass pixel position deformation, which is one of quality deterioration problems in small and medium OLED deposition process. Specifically, we derive various factors affecting the glass pixel position shift by using cause and effect diagram and identify radical reasons by using XY-matrix. As a result, it is confirmed that glass heat distortion due to the high temperature of the OLED deposition process is the most influential factor in the glass pixel position shift. In order to solve the identified factors, we analyzed the cause and mechanism of glass thermal deformation. We suggest an efficient method to minimize glass thermal deformation by applying the improvement plan of facilities using contradiction matrix in TRIZ. We show that the suggested method can decrease the glass temperature change by about 23% through an experiment.

Laser Thermal Processing System for Creation of Low Temperature Polycrystalline Silicon using High Power DPSS Laser and Excimer Laser

  • Kim, Doh-Hoon;Kim, Dae-Jin
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • 2006.08a
    • /
    • pp.647-650
    • /
    • 2006
  • Low temperature polycrystalline silicon (LTPS) technology using a high power laser have been widely applied to thin film transistors (TFTs) for liquid crystal, organic light emitting diode (OLED) display, driver circuit for system on glass (SOG) and static random access memory (SRAM). Recently, the semiconductor industry is continuing its quest to create even more powerful CPU and memory chips. This requires increasing of individual device speed through the continual reduction of the minimum size of device features and increasing of device density on the chip. Moreover, the flat panel display industry also need to be brighter, with richer more vivid color, wider viewing angle, have faster video capability and be more durable at lower cost. Kornic Systems Co., Ltd. developed the $KORONA^{TM}$ LTP/GLTP series - an innovative production tool for fabricating flat panel displays and semiconductor devices - to meet these growing market demands and advance the volume production capabilities of flat panel displays and semiconductor industry. The $KORONA^{TM}\;LTP/GLTP$ series using DPSS laser and XeCl excimer laser is designed for the new generation of the wafer & FPD glass annealing processing equipment combining advanced low temperature poly-silicon (LTPS) crystallization technology and object-oriented software architecture with a semistandard graphical user interface (GUI). These leading edge systems show the superior annealing ability to the conventional other method. The $KORONA^{TM}\;LTP/GLTP$ series provides technical and economical benefits of advanced annealing solution to semiconductor and FPD production performance with an exceptional level of productivity. High throughput, low cost of ownership and optimized system efficiency brings the highest yield and lowest cost per wafer/glass on the annealing market.

  • PDF

The Fabrication of Four-Terminal Poly-Si TFTs with Buried Channel (Buried Channel 4단자 Poly-Si TFTs 제작)

  • Jeong, Sang-Hun;Park, Cheol-Min;Yu, Jun-Seok;Choe, Hyeong-Bae;Han, Min-Gu
    • The Transactions of the Korean Institute of Electrical Engineers C
    • /
    • v.48 no.12
    • /
    • pp.761-767
    • /
    • 1999
  • Poly-Si TFTs(polycrystalline silicon thin film transistors) fabricated on a low cost glass substrate have attracted a considerable amount of attention for pixel elements and peripheral driving circuits in AMLCS(active matrix liquid crystal display). In order to apply poly-Si TFTs for high resolution AMLCD, a high operating frequency and reliable circuit performances are desired. A new poly-Si TFT with CLBT(counter doped lateral body terminal) is proposed and fabricated to suppress kink effects and to improve the device stability. And this proposed device with BC(buried channel) is fabricated to increase ON-current and operating frequency. Although the troublesome LDD structure is not used in the proposed device, a low OFF-current is successfully obtained by removing the minority carrier through the CLBT. We have measured the dynamic properties of the poly-Si TFT device and its circuit. The reliability of the TFTs and their circuits after AC stress are also discussed in our paper. Our experimental results show that the BC enables the device to have high mobility and switching frequency (33MHz at $V_{DD}$ = 15 V). The minority carrier elimination of the CLBT suppresses kink effects and makes for superb dynamic reliability of the CMOS circuit. We have analyzed the mechanism in order to see why the ring oscillators do not operate by analyzing AC stressed device characteristics.

  • PDF

Human Visual System-aware Dimming Method Combining Pixel Compensation and Histogram Specification for TFT-LCDs

  • Jin, Jeong-Chan;Kim, Young-Jin
    • KSII Transactions on Internet and Information Systems (TIIS)
    • /
    • v.11 no.12
    • /
    • pp.5998-6016
    • /
    • 2017
  • In thin-film transistor liquid-crystal displays (TFT-LCDs), which are most commonly used in mobile devices, the backlight accounts for about 70% of the power consumption. Therefore, most low-power-related studies focus on realizing power savings through backlight dimming. Image compensation is performed to mitigate the visual distortion caused by the backlight dimming. Therefore, popular techniques include pixel compensation for brightness recovery and contrast enhancement, such as histogram equalization. However, existing pixel compensation techniques often have limitations with respect to blur owing to the pixel saturation phenomenon, or because contrast enhancement cannot adequately satisfy the human visual system (HVS). To overcome these, in this study, we propose a novel dimming technique to achieve both power saving and HVS-awareness by combining the pixel compensation and histogram specifications, which convert the original cumulative density function (CDF) by designing and using the desired CDF of an image. Because the process of obtaining the desired CDF is customized to consider image characteristics, histogram specification is found to achieve better HVS-awareness than histogram equalization. For the experiments, we employ the LIVE image database, and we use the structural similarity (SSIM) index to measure the degree of visual satisfaction. The experimental results show that the proposed technique achieves up to 15.9% increase in the SSIM index compared with existing dimming techniques that use pixel compensation and histogram equalization in the case of the same low-power ratio. Further, the results indicate that it achieves improved HVS-awareness and increased power saving concurrently compared with previous techniques.

A Study on the Simulation and DSF Molding of V-groove Type Light Guide for a Backlight Unit (백라이트 유닛용 V-그루브 도광판의 전산모사 및 DSF성형에 관한 비교연구)

  • Cho K. H.;Yoon K. H.
    • Transactions of Materials Processing
    • /
    • v.14 no.3 s.75
    • /
    • pp.282-290
    • /
    • 2005
  • Nowadays, TFT-LCD is widely used as display unit of many digital devices. And, the backlight unit(BLU) is used as a light source of TFT-LCD module. In the backlight unit, the most important component is a light guide, which guides the input light to the TFT-LCD module uniformly. Recently, many researchers have focused on improving the efficiency of BLU by changing the design and structure of a light guide. In the present paper, a series of simulation was performed to find the optimal luminance distribution of emanated light from the given geometry as the first step. From the results of simulations for the light guide with given V-groove pattern, the emanated light from it is mostly affected by the groove angle. In the case of acute angle, about 74 degrees was found as optimal angle to satisfy the restrictions of angular luminance distribution, FWHM, the maximum luminance, etc. However, as far as the average luminance value was concerned, the case of 120 degrees(abtuse angle) was found to be the best while prism films were added to the BLU. As a next step the light guide samples of 74 and 120 degrees were manufactured by DSF method, which was recently proposed by the authors. Of course, most of design parameters were chosen by the aid of simulation results. Finally, the results of average luminance values were compared between the simulation and DSF molded samples.