• ETRI Journal
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• 제36권2호
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• pp.321-324
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• 2014

This letter describes a two-phase clock oxide thin-film transistor shift register that executes a robust operation over a wide threshold voltage range and clock coupling noises. The proposed circuit employs an additional Q generation block to avoid the clock coupling noise effects. A SMART-SPICE simulation shows that the stable shift register operation is established for the clock coupling noises and the threshold voltage variation from -4 V to 5 V at a line time of $5{\mu}s$. The magnitude of coupling noises on the Q(15) node and Qb(15) node of the 15th stage is respectively -12.6 dB and -26.1 dB at 100 kHz in the proposed circuit, compared to 6.8 dB and 10.9 dB in a conventional one. In addition, the estimated power consumption is 1.74 mW for the proposed 16-stage shift registers at $V_{TH}=-1.56V$, compared to 11.5 mW for the conventional circuits.

• Current Optics and Photonics
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• 제8권1호
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• pp.72-79
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• 2024

Recent flat-panel displays have become increasingly complicated to facilitate multiple display functions. In particular, the form of multilayered architectures for next-generation displays makes precise three-dimensional alignment of multiple panels a challenge. In this paper, a diffractive optical alignment marker is proposed to address the problem of three-dimensional alignment of distant dual panels beyond the depth-of-focus of a vision camera. The diffractive marker is effective to analyze the positional correlation of distant dual panels. The possibility of diffractive alignment in multilayer display fabrication is testified with numerical simulation and a proof-of-concept experiment.

• Journal of Information Display
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• 제2권3호
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• pp.48-53
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• 2001

Carbon nanotube emitters, prepared by screen printing, have demonstrated a great potential towards low-cost, largearea field emission displays. Carbon nanotube paste, essential to the screen printing technology, was formulated to exhibit low threshold electric fields as well as an emission uniformity over a large area. Two different types of triode structures, normal gate and undergate, have been investigated, leading us to the optimal structure designing. These carbon nanotube FEDs demonstrated color separation and high brightness over 300 $cd/m^2$ at a video-speed operation of moving images. Our recent developments are discussed in details.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.241.2-241.2
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• 2014

We present highly transparent liquid crystal displays (LCDs) using hybrid films based on carbon nanomaterials, metal grid, and indium-tin-oxide (ITO) grid. Carbon based nanomaterials are used as transparent electrodes because of high transmittance. Despite of their high transmittance they have relatively high sheet resistance. To solve this problem, we applied grid and made hybrid conductive films based on carbon nanomaterials. Conventional photolithography processes were used to make a grid pattern of metal and ITO. To fabricate transparent conductive films, carbon nanotube (CNT) ink was spin coated on the grid pattern. The transparency of the conductive film was controlled by shape and size of the grid pattern and the thickness of CNT films. The optical transmittance of CNT-based hybrid films is 92.2% and sheet resistance is also reduced to $168{\Omega}/square$. These substrates were used for the fabrication of typical twisted nematic (TN) LCD cells. From the characteristics of LCD devices such as transmittance, operating voltage, voltage holding ratio our devices were comparable to those of pristine ITO substrates. The result shows that the hybrid conductive films based on carbon nanomaterials could be alternative of ITO for the highly transparent LCDs.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2004년도 가을 학술발표논문집 Vol.31 No.2 (2)
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• pp.565-567
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• 2004

최근 컴퓨터 환경은 매우 빠르게 발전하고 있지만, 사람들은 여전히 종이로 된 문서를 사용한다. 본 논문은 프로젝션 화면 내에서 종이 문서의 기능을 향상시킨 Advanced Paper Document (APD)를 제안한다. APD는 종이 문서와 디지털 문서를 결합시키기 위해서 부가적인 장치 없이, 사용자의 손을 이용한 문서의 선택과 조작 등의 다양한 명령을 수행한다. APD는 종이 문서와 디지털 문서의 장점을 모두 가지고 있으며, 사용자에게 자연스럽고 직관적인 환경을 제공한다. 실험 결과를 통해서, APD가 종이 문서와 디지털 문서의 기능을 결합하는 데에 적합하며, 손의 추출 및 인식과 문서의 검색에서 만족스러운 성능을 보여줌을 확인하였다.

• Journal of Information Display
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• 제1권1호
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• pp.35-41
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• 2000

Manganese-doped $Zn_2SiO_4$ phosphors well known as a green emitter with high luminescence efficiency were prepared by the homogeneous precipitation method, and their photoluminescence properties under vacuum-ultraviolet (VUV) excitation were investigated. $Zn_2SiO_4$:Mn phosphors obtained by this method have exhibited a high luminance of property and a spherical shape of particles. In particular, the green emission intensity of zinc orthosilicate prepared as containing around 2 mole% of manganese was much stronger than that of the commercial $Zn_2SiO_4$:Mn phosphor, while the decay time was longer. However, addition of $Al^{3+}$ and $Li^+$ into $Zn_2SiO_4$:Mn composition has significantly diminished the decay time of the phosphor without much degradation of the emission intensity.

• ETRI Journal
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• 제34권3호
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• pp.470-473
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• 2012

In this letter, the constant driving power reduction ratio has been achieved for column drivers regardless of the input image by incorporating a new static power reduction scheme into the previous dynamic power reduction method. The measured power reduction ratio is around 50% for a 120 Hz liquid crystal display panel in such cases of still input video and fallback.

• 폴리머
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• 제39권1호
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• pp.185-190
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• 2015

LC242와 같이 분자량이 큰 광반응성 액정 물질은 온도를 낮출 때 액정상에서 결정으로의 변화가 빠르지 못하여 액정분자를 재결정을 할 때는 충분한 시간이 필요하다. 액정 상태에서 분자의 배열 정도가 온도에 따라 영향받는 것을 알 수 있는데, 액정상의 LC242는 온도가 높아짐에 따라 액정 배열을 한 방향으로 계속 유지하고 있어도 온도에 따른 LC242 분자들의 움직임에 의하여 조금씩 배열이 달라져 복굴절의 변화를 가져오는 것을 알 수 있다. 광반응성 액정을 경화할 때 액정 상의 온도에서 광조사를 하면 고체상의 경우보다 반응 속도가 빠르고 경화도가 훨씬 많이 진행되는 것을 Photo-DSC 실험과 FTIR을 이용하여 정량적으로 분석하였다.

• 폴리머
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• 제38권3호
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• pp.358-363
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• 2014

원자력현미경(AFM) tip을 표면 처리하여 임프린트용 acrylate 레진과의 접착력을 측정하였다. 표면 처리를 하지 않은 실리콘 tip에 비하여 $CH_4$ 플라즈마로 소수성 처리한 경우 접착력은 38% 감소한 반면 친수성의 $O_2$ 플라즈마로 처리한 경우에는 접착력이 1.6 배 증가하였다. 이러한 AFM 결과들은 정성적 실험 결과 밖에 얻을 수 없는 cross-cut 접착실험에 비하여 매우 구체적인 정량적 결과들을 제공하였다. 나노 크기의 임프린트 패턴을 전사하는 경우, 몰드와 레진 사이 접촉 면적이 커져서 시료 전체의 접착력이 커지기 때문에 패턴 크기가 작아지는 나노임프린트 공정에서는 몰드 표면 처리 문제가 더욱 중요하게 되는 것을 알 수 있었다.

• 한국분말재료학회지
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• 제22권1호
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• pp.27-31
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• 2015

Flat panel display devices are mainly used as information display devices in the 21st century. The worldwide waste flat panel displays are expected at 2-3 million units but most of them are land-filled for want of a proper recycling technology More specifically, rare earth metals of La and Eu are used as fluorescent materials of Cold Cathode Flourscent Lamp(CCFL)s in the waste flat panel displays and they are critically vulnerable and irreplaceable strategic mineral resources. At present, most of the waste CCFLs are disposed of by land-filling and incineration and proper recovery of 80-plus tons per annum of the rare earth fluorescent materials will significantly contribute to steady supply of them. A dearth of Korean domestic research results on recovery and recycling of rare earth elements in the CCFLs prompts to initiate this status report on overseas research trends and noteworthy research results in related fields.