• 천문학회보
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• 제37권1호
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• pp.93.2-93.2
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• 2012

Point Spread Function (PSF) is one of the most important optical characteristics for describing the performance of a telescope. And a concept of subpixelization is inevitable in evaluating the undersampled PSF (Shin and Sakurai 2009). Then, the internal structure of Yohkoh SXT CCD pixel is not uniform: For the top half of pixel area, the X-ray should pass a so-called gate structure where the charges are transferred to an output amplifier. This gate structure shows energy-dependent sensitivity (Tsuneta et al. 1991). For example, for Al-K (8.34 A) X-ray emission, the transmission of the polysilicon gate is about 0.9. Also, for the peak coronal response of the SXT thin filters, around 17 angstrom (0.729 keV), the transmission of the gate is about 0.6, falling off sharply towards longer wavelengths. It should be noted that this spectrally dependent non-uniform response of each CCD pixel will certainly have a noticeable effect on the properties of the PSF at longer wavelengths. Therefore, especially for analyzing the undersampled PSF of low energy source, a careful consideration of non-uniform internal pixel structure is required in determining the shape of the PSF core. The details on the effect of gate structure will be introduced in our presentation.

• 한국인터넷방송통신학회논문지
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• 제12권3호
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• pp.29-35
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• 2012

본 논문에서는 MPEG(Moving Picture Experts Group) 영상 디코더에서 영상을 압축, 비교, 복원, 저장한후 디코딩 처리하는 방법을 종래의 픽셀 단위로 처리하는 방법과는 다르게 영상의 단위 화소 주변을 군집화소로 분류한 후 이를 클러스터링하여 오버랩정도를 결정 한다. 오버랩 정도의 임계치값을 결정하는데는 패턴식별을 취한후 샘플 패턴에 대한 기하구조의 파악과 결정함수의 도출로 활용된다. 특징공간이 4차원 이상이면 주어진 패턴 구조를 시각적으로 관찰할 수 없다. 이 때, 분포구조를 고찰해 볼수 있는 방법은 군집중심간의 거리, 군집별 패턴의 수 및 표준편차 등을 이용하는 방법이다. 임계치 값을 넘는 중복화면은 소거되고 넘지않는 군집화면은 패턴인식으로 복원된후 동영상으로 구현된다. 이방법이 기존의 픽셀 단위 처리하는 방법 과는 20%정도의 메모리 감축과 15%정도의 화면 복원에 성능이 향상된 것으로 판정된다.

• JSTS:Journal of Semiconductor Technology and Science
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• 제5권2호
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• pp.102-106
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• 2005

A low dark current CMOS image sensor (CIS) pixel without any process modification is developed. Dark current is mainly generated at the interface region of shallow trench isolation (STI) structure. Proposed pixel reduces the dark current effectively by separating the STI region from the photodiode junction using simple layout modification. Test sensor array that has both proposed and conventional pixels is fabricated using 0.18 m CMOS process and the characteristics of the sensor are measured. The result shows that the dark current of the proposed pixel is 0.93fA/pixel that is two times lower than the conventional design.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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• pp.621-624
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• 2006

Pixel structure of the fringe-field switching (FFS) mode to improve transmittance has been studied. New FFS structures related to the electrode structure at the edges of pixel, and the pixel electrode width and distance between electrodes was optimized. The former improves transmittance by minimizing the region of disclination lines. The latter improves it by increasing light efficiency above center of electrodes and also response time.

• 감성과학
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• 제17권3호
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• pp.3-14
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• 2014

2009년 아이폰의 국내 출시 이후 스마트폰의 보급이 급격히 증가하여 기존에 다양한 장비로 수행되어 오던 작업이 스마트폰으로 대체되었다. 이 과정에서 스마트폰의 작은 화면을 통하여 글자를 읽는 과제를 수행하는 비중이 상당히 증가하였다. 본 연구에서는 일상적인 스마트폰 사용 환경에서 디스플레이 요인(화소 밀집도, 화소 하부구조, 휘도)과 환경 요인(조명 조도)이 글자를 읽을 때의 가독성 관련 불편감에 어떤 영향을 미치는지를 확인하였다. 그 결과 지각된 가독성 관련 불편감에 영향을 미치는 것은 주로 화소 밀집도로, 화소 밀집도가 300 PPI미만인 경우 글자를 읽는데 불편함을 느낀다는 것을 확인하였다. 조명 조도는 제한적인 영향을 보였다. 참가자들은 조명 조도가 변화 할 때 변화하지 않을 때 보다 더 큰 가독성 관련 불편감을 보고하였다. 화소 하부구조와 밝기는 가독성 관련 불편감에 영향을 미치지 않았다. 이 결과를 바탕으로 가독성을 고려할 때 다양한 크기를 가지는 스마트 기기(스마트 폰, 태블릿 컴퓨터)에서 가독성을 해치지 않는 해상도의 하한선을 제안하였다.

• 센서학회지
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• 제18권6호
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• pp.475-484
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• 2009

In this paper, an analysis of the complementary CMOS active pixel and readout circuit is carried out. Complementary pixel structure which is different from conventional 3TR APS structure consists of photo diode, reset PMOS, several NMOSs and PMOSs sets for complementary signals. Proposed CMOS image sensors pixel has been fabricated using 0.5 standard CMOS process. Measured results show that the output signal range is from 0.8 V to 3.8 V. This output signal range increased 125 % compared to conventional 3TR pixel in the condition of 5 V power supply.

• Journal of the Optical Society of Korea
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• 제20권6호
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• pp.794-798
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• 2016

A polymer-stabilized vertical alignment (PS-VA) mode with fishbone-shaped pixel electrode structure is mainly used in large-sized liquid crystal displays (LCDs) owing to its advantages such as wide viewing angle, good transmittance and fast response time. One drawback of this mode is a main bone electrode, which crosses in the center of a pixel. It causes the transmittance to decrease badly because LCs cannot be reoriented in this region, and thus, it is particularly unfavorable in an ultra-high-definition LCD. Here, we propose an innovative structure with the main bone electrode relocated to the edge area in a pixel, and investigate how this reverse directed fishbone-shaped pixel electrode structure affects electro-optic characteristics. The proposed structure shows enhanced electro-optic performance, such as the higher transmittance and the faster response time than the conventional VA mode with fishbone-shaped pixel electrode structure.

• Journal of the Optical Society of Korea
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• 제18권6호
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• pp.777-782
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• 2014

This paper proposes an RGB to RGBY color conversion algorithm for liquid crystal display (LCD) using RGW pixel structure with two-field (yellow and blue) sequential driving method. The proposed algorithm preserves the hue and saturation of the original color by maintaining the RGB ratio, and it increases the luminance. The performance of the proposed RGBY conversion algorithm is verified using the MATLAB simulation with 24 images of Kodak lossless true color image suite. The simulation results of average color difference CIEDE2000 (${\delta}E^*_{00}$) and scaling factor are 0.99 and 1.89, respectively. These results indicate that the average brightness is increased 1.89 times compared to LCD using conventional RGB pixel structure, without increasing the power consumption and degrading the image quality.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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• pp.295-298
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• 2008

We developed a novel PVA pixel design for mobile application with excellent off-axis image quality and optical performance by introducing Active Level Shift technology and optimizing pixel structure. Our new pixel design enables better off-axis image quality without sacrificing other optical properties compared with a conventional mPVA structure.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2002년도 International Meeting on Information Display
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• pp.456-458
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• 2002

On the half area of a pixel, pretilt angle was decreased by UV radiation and two domain TN was induced by the pretilt difference. In this structure, ITO slit was made inside pixel electrode on the TFT substrate to stabilize domain boundaries. The result shows that this structure is more resistant to outside stress and unwanted domain deformation is prevented.