• Proceedings of the IEEK Conference
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• 2005.11a
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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.

• Tribology and Lubricants
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• v.14 no.3
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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.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.46 no.4
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• pp.45-52
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• 2009

We proposed a new pixel circuit and driving method for the large-area, high-luminance AMOLED applications in this study. We designed with the low-temperature poly-silicon(LTPS) thin film transistors(TFTs) that has poor uniformity but stable characteristic. To improve the uniformity of an image, the threshold voltage($V_{TH}$) and the mobility of the TFTs can be compensated together. The proposed method overcomes the previous methods for mobility compensation, and that is profitable for large-area applications. Black data insertion was introduced to improve the characteristics for moving images. AMOLED panel can operate in two compensation mode, so the luminance degradation by mobility compensation can be released. The scan driver for controlling the pixel circuits were optimized, and the compensation mode can be controlled simply by that. Final driving signal has large timing margin, and the panel operates stably. The pixel circuit was designed for 14.1" WXGA top-emission ANGLED panel. The non-uniformity of the designed panel was estimated under 5% for the mobility compensation time of 1us.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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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.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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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.

• Proceedings of the KIEE Conference
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• 1998.07d
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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.

• Journal of the Semiconductor & Display Technology
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• v.19 no.1
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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.

• Journal of the Semiconductor & Display Technology
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• v.20 no.4
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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 (V_th) of a TFT during operation. When designing an OLED pixel with circuit simulation tool such as SPICE, a designer needs to take V_th 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 V_th shift function is implemented. The simulation results show that the compensation circuits improve the reliability at the beginning of each frame, but V_th shifts from all TFTs in a pixel need to be considered to improve long-time reliability.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.12
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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.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.49 no.5
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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.