• 제목/요약/키워드: Film compensation

검색결과 131건 처리시간 0.027초

OCB TFT-LCD의 시야각 특성 개선을 위한 보상필름 최적화 설계 (Optimal design of optical compensation film to improve viewing angle characteristics of OCB TFT-LCDs)

  • 양동민;박우상
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2005년도 추계종합학술대회
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    • pp.853-856
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    • 2005
  • we proposed the optimized conditions of the uniaxial and biaxial compensation films to suppress the light leakage to improve viewing angle characteristics. Compared with conventional OCB mode, the maximum transmittance is increased about 30% and the minimum transmittance is slightly decreased. From here results, we can about OCB mode with wide viewing angle and high contrast ratio.

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스퀴즈 필름 댐퍼의 디지탈 제어 (A Digital Control of Squeeze Film Damper)

  • 송용한;최현석;최세헌;임윤철
    • Tribology and Lubricants
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    • 제14권3호
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    • pp.24-31
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    • 1998
  • A new type squeeze film damper is proposed and its dynamic characteristics are investigated experimentally. The new one has a pulsating flow supply system which properly adds high pressure oil to the oil film of the damper so that the rotor vibration can be controlled actively. As the result, the amplitude of the rotor vibration can be reduced considerably. The algorithm which compensates the phase lag of servo valve as well as the high-performance servo valve are required in order that a new type squeeze film damper can be more effective device to attenuate the rotor vibration than typical one.

LTPS TFT의 Vth와 mobility 편차를 보상하기 위한 AMOLED 화소 회로 (AMOLED Pixel Circuit with Electronic Compensation for Vth and Mobility Variation in LTPS TFTs)

  • 우두형
    • 대한전자공학회논문지SD
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    • 제46권4호
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    • pp.45-52
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    • 2009
  • 본 연구를 통해서 대 면적, 고 휘도 AMOLED 응용에 적합한 화소 회로와 이에 대한 구동 방식을 제안하였다. 균일도는 다소 떨어지지만 안정성이 뛰어난 저온 다결정 실리론(LTPS) 박막 트랜지스터(TFT)를 기반으로 설계했다. 영상 화소의 균일도를 향상시키기 위해, 화소 TFT의 $V_{TH}$와 이동도 편차를 함께 보상할 수 있도록 했다. 기존의 이동도 보상 회로가 갖는 문제점을 극복하여 대 면적 패널에 적합하도록 했고, 동영상 특성을 개선하기 위해 black data insertion 방식을 도입하였다. 이동도 보상 시 휘도가 떨어지는 문제를 개선하기 위해, 패널이 두 가지 보상 모드에서 동작할 수 있도록 하였다. 화소 회로를 제어하기 위한 스캔 구동 회로를 최적화하여, 이를 통해서 보정 모드를 쉽게 제어할 수 있었다. 최종 구동 타이밍은 여유 있는 마진으로 안정적인 동작이 가능하다. 14.1" WXGA top emission AMOLED 패널에 대해 설계했으며, 이동도 보상 시간을 1us로 했을 때 패널의 불균일도는 5% 이하로 예측되었다.

Thin-Film Photosensors for OLED Flat-Panel Displays

  • Cok, Ronald S.;Nishikawa, Ryuji;Ogawa, Takashi
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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    • pp.277-280
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    • 2004
  • Thin-film photosensors on organic light emitting diode (OLED) glass substrates using active-matrix OLED TFT manufacturing processes have been constructed and optimized, and their performance has been characterized. Suitable control circuitry and applications are proposed. The photosensors may be integrated into OLED displays for detection of ambient illumination and for detection of OLED light emission, thereby enabling output, uniformity, and aging compensation.

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Coatable Retarder Technology for LCD Home TV

  • Lazarev, Alexander;Geivandov, Artur;Kasianova, Irina;Kharatiyan, Ellina;Lazarev, Pavel;Palto, Sergey
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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    • pp.1083-1086
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    • 2008
  • Crysoptix KK has developed low-cost coatable retarder technology. A full range of coatable retardation films with tunable value of biaxiality (NZ factor) has been developed for the first time. Tunable NZ factor allows efficient compensation of modern VA and IPS mode LCD with just single retardation film.

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지능형 박막 스트레인 게이지 압력 변환기 (Smart Pressure Transducer with Cu-Ni Thin Film Strain Gages)

  • 박찬원;이성재;민남기
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1998년도 하계학술대회 논문집 D
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    • pp.1564-1567
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    • 1998
  • This paper presents a smart thin film pressure transducer which is highly suitable for a precise and remote measurement of pressure and has the following smart functions: automatic zero tracking, automatic span adjustment, temperature compensation, continuous self-diagnostics for faults(open strain gages, abnormal data, incorrect A/D conversion, and overpressure), data memory and multi-drop communication with PC.

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Recent Progress on Voltage Drop Compensation in Top Emission Organic Light Emitting Diodes (OLED)

  • Jeong, Byoung-Seong
    • 반도체디스플레이기술학회지
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    • 제19권1호
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    • pp.49-54
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    • 2020
  • The voltage drop due to the thin cathode film at the large size top emission OLED panel was successfully compensated with making electrical contact between thin cathode and anode auxiliary electrode by 355nm wavelength of laser. It was found that the luminance uniformity dramatically increased from around 15% to more than 80% through this electrical compensation between thin cathode and anode auxiliary electrode. Moreover, the removing process for EL materials on the anode auxiliary electrode process by laser was very reliable and stable. Therefore, it is thought that the EL removal method using laser to make electrical contacts is very appropriate to mass production for such a large size top emission OLEDs to obtain high uniformity of luminance.

과도상태 시뮬레이션을 사용한 OLED 픽셀 회로의 신뢰성 분석 방안 연구 (Study on the Reliability of an OLED Pixel Circuit Using Transient Simulation)

  • 정태호
    • 반도체디스플레이기술학회지
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    • 제20권4호
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    • pp.141-145
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    • 2021
  • The brightness of the Organic Light Emitting Diode (OLED) display is controlled by thin-film transistors (TFTs). Regardless of the materials and the structures of TFTs, an OLED suffers from the instable threshold voltage (Vth) of a TFT during operation. When designing an OLED pixel with circuit simulation tool such as SPICE, a designer needs to take Vth shift into account to improve the reliability of the circuit and various compensation methods have been proposed. In this paper, the effect of the compensation circuits from two typical OLED pixel circuits proposed in the literature are studied by the transient simulation with a SPICE tool in which the stretched-exponential time dependent Vth shift function is implemented. The simulation results show that the compensation circuits improve the reliability at the beginning of each frame, but Vth shifts from all TFTs in a pixel need to be considered to improve long-time reliability.

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)
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    • 제11권12호
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    • pp.5998-6016
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    • 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.

압전세라믹 기판과 고자왜박막을 결합한 스마트액츄에이타 (Smart Actuators Composed of Piezoelectric Ceramics and Highly Magnetostrictive films)

  • 신광호
    • 대한전기학회논문지:전기물성ㆍ응용부문C
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    • 제49권5호
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    • pp.289-293
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    • 2000
  • This paper presents a study on the linear compensation of nonlinear hysteric actuators using the highly magnetostrictive film pattern as a strain sensor. Elements had a hybrid structure, in which thin soft glass substrate with the highly magnetostrictive amorphous FeCoSiB film was bonded on the PZT piezoelectric substrate. The magnetostrictive film as a strain sensor detects the deflection of an actuator, and a voltage signal from the strain sensor related to the deflection of an actuator is used for the linear control of an actuator.

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