• Title/Summary/Keyword: image sticking

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Improvement of Photo-Alignment Characteristics for Device Applications

  • Hwang, Yong-Jae;Choi, Kil-Yeong;Yi, Mi-Hie;Hong, Sung-Hwan;Shin, Dong-Myung
    • 한국정보디스플레이학회:학술대회논문집
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    • 2007.08a
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    • pp.867-870
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    • 2007
  • In order to solve image sticking phenomena, the gas-phase and liquid-phase interfacial reactions of photosensitive polyimide can annihilate photoreactive carbon-carbon double bonds, which remain after photo-alignment process. The annihilation processes dramatically affect residual DC and photochemical reorientation of photoactive functional groups.

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Novel Driving Scheme to remove residual image sticking in AMOLED

  • Parikh, Kunjal;Choi, Joon-Hoo;Cho, Kyu-Sik;Huh, Jong-Moo;Park, Kyong-Tae;Jeong, Byoung-Seong;Park, Yong-Hwan;Kim, Tae-Youn;Lee, Baek-Woon;Kim, Chi-Woo
    • 한국정보디스플레이학회:학술대회논문집
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    • 2008.10a
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    • pp.553-556
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    • 2008
  • We hereby report novel driving scheme to eliminate effect of "residual" image sticking (RRI) problem which arises due to hysteresis problem in Thin Film Transistor (TFT) in AMOLED Displays. The driving scheme applies "black" voltage after every data voltage period in order to drive AMOLED in uni-direction. The system can be easily implemented with 120 Hz driving scheme which is well matured in AMLCD industries. Our analyses show systematic evaluation of the problem and thereby solving it by simple methods which will be significantly effective of driving OLED towards mass manufacturing stage.

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A Video Data Correction Method for the Non-Uniform Electro-Optical Characteristics of the Pixels in AMOLED Displays

  • Min, Ung-Gyu;Kwon, Oh-Kyong
    • Journal of Information Display
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    • v.10 no.2
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    • pp.80-86
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    • 2009
  • The variation of the electrical characteristics of thin-film transistors (TFTs) causes a non-uniform image quality problem, and the differential aging of organic light-emitting diode (OLED) devices causes an image-sticking problem. A video data correction method is proposed herein as an effective solution to the non-uniform electro-optical characteristics of the pixels in activematrix organic light-emitting diode (AMOLED) displays. The results of the simulation that was conducted show that the proposed method successfully senses the electrical characteristics of TFTs and the degradation of OLEDs and effectively compensates for them.

The improvement of moving picture quality in TFT-LCD with Blinking Backlight System and Liquid Crystal Overdriving Methode (Blinking Backlight System과 Liquid Crystal Overdriving Methode를 사용한 TFT-LCD의 동영상 화질개선을 위한 연구)

  • Han, Jung-Min;Kim, Jong-Hwan;Kim, Young-Hwan;Kim, Gwi-Yeol;Seo, Dae-Shik
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2005.05a
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    • pp.146-149
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    • 2005
  • In applying LCD to TV application, one of the most significant factors to be improved is image sticking on the moving picture. LCD is different from CRT in the sense that it's continuous passive device, whichholds images in entire frame period, while impulsetype device generate image in very short time. We realized articulate image generation similar to CRT by CCFL blinking drive and TN-LCD overdriving. As a result, reduced image sticking phenomenon was validated by naked eye and response time measureme.

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Development of SDI Signal generator for Large size TFT-LCD (대형 TFT-LCD용 SDI 신호 생성기의 개발)

  • Choi, Dae-Seub;Sin, Ho-Chul
    • Journal of Satellite, Information and Communications
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    • v.9 no.1
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    • pp.13-16
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    • 2014
  • In applying LCD to TV application, one of the most significant factors to be improved is image sticking on the moving picture. LCD is different from CRT in the sense that it's continuous passive device, which holds images in entire frame period, while impulse type device generate image in very short time. To reduce image sticking problem related to hold type display mode, we made an experiment to drive TN-LCD like CRT. We made articulate images by fast refreshing images, and we realized the ratio of refresh time by counting between on time and off time for video signal input during 1 frame (16.7ms). Conventional driving signal cannot follow fast on-off speed, so we evaluated new signal generator using SDI (Serial Data Interface) mode signal generator. We realized articulate image generation similar to CRT by high fast full HD (High Definition) signals and TN-LCD overdriving. As a result, reduced image sticking phenomenon was validated by naked eye and response time measurement.

Study of Blurring Free TFT-LCD Using Short Persistance Cold Cathode Fluorescent Lamp in Blinking Backlight Driving (단잔광 냉음극관을 이용한 잔상없는 TFT-LCD에 관한 연구)

  • Choi, Dae-Seub;Sin, Ho-Chul
    • Journal of Satellite, Information and Communications
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    • v.7 no.3
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    • pp.145-148
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    • 2012
  • In applying LCD to TV application, one of the most significant factors to be improved is image sticking on the moving picture. LCD is different from CRT in the sense that it's continuous passive device, which holds images in entire frame period, while impulse type device generate image in very short time. To reduce image sticking problem related to hold typedisplay mode, we made an experiment to drive TN-LCD like CRT. We made articulate images by turn on-off backlight, and we realized the ratio of Back Light on-off time by counting between on time and off time for video signal input during 1 frame (16.7ms). Conventional CCFL (cold cathode fluorescent lamp) cannot follow fast on-off speed, so we evaluated new fluorescent substances of light source to improve residual light characteristic of CCFL. We realized articulate image generation similar to CRT by CCFL blinking drive and TN-LCD overdriving. As a result, reduced image sticking phenomenon was validated by naked eye and response time measurement.

Development of combustion zone monitoring system for a blast furnace (용광로 연소대 관리시스템 개발)

  • Choi, Tae-Hwa
    • Journal of Institute of Control, Robotics and Systems
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    • v.3 no.3
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    • pp.318-322
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    • 1997
  • A prototype of combustion zone monitoring system as been developed and installed into tuyeres of the blast furnace. The system consists of CCD(charge coupled device) cameras, sonic flow meters, an image processor and a personal computer. The personal computer collects raceway luminance data and operational data from the image processor that is connected to the color CCD camera from the blast furnace process computer, respectively. In addition, the sonic flow meters supply coal injection rate data to the personal computer. Then, the personal computer evaluates the combustion conditions with the raceway inspection algorithm. This integrated monitoring system allows us to detect abnormal raceway conditions and the clogging status of coal injection pipe. The image processing techniques of the system enable us to effectively monitor unburnt coal sticking to tuyere tip and injection lance wear conditions. Such a developed system ensures rapid and precise raceway inspection. The image processing capability of the system has helped operator to early detect both the unburnt coal sticking problem and the errosion problem of injection lance. Furthermore, the system could control the abnormal raceway condition based the the analysis results obtained from combustion monitoring.

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Electro Optical Study of the Liquid Crystals & Polyimides For High Reliability Performance

  • Lee, S.M.;Noh, M.;Ko, T.W.;Choi, H.C.;Lee, S.W.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2005.07b
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    • pp.1484-1486
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    • 2005
  • To achieve the high reliability performance in IPS cell, finding a good combination of Liquid Crystal (LC) materials and Polyimide (PI) is very important as they play a key role in IPS cell. Several LC materials and PIs have been introduced for preparation of their different combinations. Electro optical characteristics such as voltage holding ratio, residual DC and AC image sticking have been investigated for the different system of the LC material and PI in the test panels in an attempt to find the effects on the display reliability performance and image sticking.1)3)

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A study on the method of OLED device's lifetime test (OLED 소자의 수명 평가법에 관한 연구)

  • Choi, Young-Tae;Cho, Jai-Rip
    • Journal of the Korea Safety Management & Science
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    • v.10 no.4
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    • pp.145-152
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    • 2008
  • According to the Korea Agency for Technology and Standards under the Commerce Ministry, OLED device's lifetime is defined 50% drop of luminance. OLED device is self-emitting operating device, that means it becomes different color between pixels under using environment. That's reason of the different luminance drop ratio & chromaticity coordinates shift ratio with time. The problem is there is not recovered after luminance drop and color shift. We can recognize the difference of color as image sticking. First we studied when human recognize the difference of color and second we apply the method of OLED device's lifetime test that's able to check different color between pixels.