• 한국광학회지
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• 제14권3호
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• pp.236-243
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• 2003

본 논문에서는 구면수차와 Stiles-Crowford 효과를 고려하여 인간의 눈을 모델링한 정밀모형안과 등가인 렌즈모듈 모형안의 설계에 관하여 논의하였고, 렌즈모듈 모형안을 적용한 Head Mounted Display(HMD)용 광학계를 설계 및 평가하였다. HMD용 광학계에서 요구되는 소형화, 고성능 및 고해상도 등의 필수조건들을 만족시키기 위해 회절광학소자와 비구면을 이용하여 색수차와 단색수차를 보정하였다. SVGA급 480,000화소를 갖는 0.47 인치 micro-display, 플라스틱 hybrid 렌즈, 그리고 렌즈모듈 모형안으로 HMD용 광학계를 구성하였다. 설계된 광학계의 초점거리는 31.25 mm, FOV는 24H$\times$18V$\times$30D degrees, 그리고 전장길이는 59.1 mm이다. 결과적으로, 사용자가 편안함을 느낄 수 있는 HMD에 유용한 광학계를 얻었다.

• Journal of Korean Vacuum Science & Technology
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• 제3권1호
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• pp.33-37
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• 1999

We present, for the first time, a prototype active-matrix field emission display (AMFED) with 25$\times$25 pixels in which polycrystalline silicon fie이 emitter array (poly-Si FEA) and thin-film transistor (TFT) were monolityically intergrated on an insulating substrate. The FEAs showed relatively large electron emissions above at a gate voltage of 50 V, and the TFTs were designed to have low off-stage currents even though at high drain voltages. The intergrated poly-Si TFT controlled electron emissions of the poly-Si FEA actively, resulting in improvement in the emission stability and reliability along with a low-voltage control of field emission below 25V. With the prototype AMFED we have displayed character patterns by low-boltage pertipheral circuits of 15 V in a high vacuum chamber.

• Korea-Australia Rheology Journal
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• 제19권3호
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• pp.165-169
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• 2007

The light guide plate (LGP) of LCD-BLU (Liquid Crystal Display-Back Light Unit) is usually manufactured by forming numerous dots by etching process. However, the surface of those etched dots of LGP is very rough due to the characteristics of etching process, so that its light loss is relatively high due to the dispersion of light. Accordingly, there is a limit in raising the luminance of LCD-BLU. In order to overcome the limit of current etched-dot patterned LGP, micro-lens pattern was tested to investigate the possibility of replacing etched pattern in the present study. The micro-lens pattern fabricated by the modified LiGA with thermal reflow process was applied to the optical design of LGP. The attention was paid to the effects of different optical pattern type (i.e. etched dot, micro-lens). Finally, the micro-lens patterned LGP showed better optical qualities than the one made by the etched-dot patterned LGP in luminance.

• Journal of Information Display
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• 제6권2호
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• pp.1-6
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• 2005

We demonstrated stability-enhanced liquid crystal (LC) displays using pixel-isolated LC mode in which LC molecules are isolated in pixel by horizontal polymer layer and vertical polymer wall. The device shows good electro-optic properties against external point or bending pressure due to the polymer structures. The polymer wall acts as supporting structure from mechanical pressure and prevents the cell gap from bending. Moreover, the polymer layer acts as an adhesive to ensure a tight attachment of the two substrates. We present herein various methods for producing polymer structures by using an anisotropic phase separation from LC and polymer composites or patterned micro-structures for stable flexible liquid crystal displays.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.560-563
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• 2004

Invar is a compound metal of Fe-Ni system and contain 36％ Ni. The most distinction characteristic of Invar is the coefficient of thermal expansion is 1.0 10$^{-6}$ /$^{\circ}C$. That is a tenth of general steel material. This low thermal expansion characteristic of Invar is applied to the missile, aircraft, monitor CRT and frontier display's shadow mask such as FED and OLED. The usage of the Invar shadow mask for display is increasing due to the requirement of larger size and flatness monitor. The Invar shadow mask is machined by two ways electro-forming and laser now. However the electro-forming takes a too long time and the laser machining is accompanied with Burr. In this study, PEMM(pulse electrochemical micro machining) is conducted to machine the micro hole to the Invar and 80${\mu}{\textrm}{m}$ hole was machined.

• 반도체디스플레이기술학회지
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• 제12권3호
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• pp.29-34
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• 2013

Solar cell has been considered as renewable green energy. Its silicon wafer thickness is thinner due to manufacturing cost and accordingly micro cracks is often generated in the process. Micro cracks result in bad quality of solar cell, and so their accurate and reliable detection is required. In this paper, near-infrared optics system is newly designed based on the analysis of near-infrared transmittance characteristics and its important parameters are optimally selected using the design of experiment for micro crack detection in solar cell wafer. The performance of the proposed method is verified using several experiments.

• 센서학회지
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• 제25권6호
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• pp.399-405
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• 2016

Scent diffuser using micro-pore piezo actuator achieved a commercial success because of its cheap production cost, but it is easy to be use for IT-based contents due to difficulty of scent intensity control. To solve this problem, we control the emission amount of scent diffuser by changing amplitude and frequency of input voltage applied to micro-pore piezo actuator. And, we analyzed the effect of density of cotton core on emission amount and a relationship between hole-size of mesh in piezo actuator and viscosity of scents to design a mechanically optimal scent device.

• 반도체디스플레이기술학회지
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• 제9권3호
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• pp.5-9
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• 2010

Recently, the important issues of solar cell are low cost and high efficiency. Making low cost and high efficiency solar cell, there are many effects to development of inexpensive wafer, simplify process and improve optical, electrical properties. In this the study, the 2 step texturing method using micro blaster was developed to decrease reflection of incident lights. Air bridge electrode structure is suggested to expand the effective surface area and decrease the series resistance of finger electrode. The effects of 1 step texturing and 2 step texturing by micro blaster are compared. Reflectance of 1 step and 2 step texturing are measured 28.7% and 25.5%, respectively. The reflectance of 2 step texturing sample is lower about 3.2% than 1 step textured sample.

• 반도체디스플레이기술학회지
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• 제20권3호
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• pp.77-82
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• 2021

This numerical study focuses on the analysis of fume particle dispersion characteristics over the surface of target workpiece in laser micro-hole machining process. The effects of oblique stagnation flow over fume generating machining point are examined by carrying out a series of three-dimensional random particle simulations along with probabilistic particle generation model and particle drag correlation of low Reynolds number. Present computational model of fume particle dispersion is found to be capable of assessing and quantifying the fume particle contamination in precision hole machining which may influenced by different types of air flow patterns and their flow intensity. The particle size dependence on dispersion distance of fume particles from laser machining point is significant and the effects of increasing flow oblique angle are shown quite differently when slot blowing or slot suction flows are applied in micro-hole machining.

• 한국광학회:학술대회논문집
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• 한국광학회 2003년도 제14회 정기총회 및 03년 동계학술발표회
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• pp.4-4
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• 2003

Diffractive- and micro-optics technology Provides new degrees of freedom for the design and optimization of optical systems. In this talk emphasis will be placed on recent advances in the design and fabrication of precision, micro- structured optical elements and their applications in the optical telecommunication, vision-care, illumination and display markets. (omitted)