• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1048-1052
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• 2008

Difficulties in developing process of Liquid Crystal Display(LCD) products such as frequent design modifications, various design requirements, and short-term development period bring on the need of integrated design approach that is efficient and easy to handle. Back Light Unit(BLU) of the LCD, which drastically affects the optical performance of LCD products, is divided into in-coupling part and out-coupling part. Serration of the in-coupling part flattens the light received from point light sources and dot pattern of the out-coupling part regularizes the light sent to screen. Therefore, the optical performance of a LCD product is largely influenced by the shape of serration and the arrangement of dot pattern. In this research, a new design approach which enables to improve the optical performance of LCD products and overcome the prementioned difficulties in developing process of LCD products is proposed. The shape of serration is parameterized to 3 parameters and out-coupling part is partitioned into 10 partitions to apply the optimization technique to this problem. 3 parameters for the shape of serration and densities of 10 partitions are used as design variables in the design optimization. Optical simulation tool named SPEOS is used to evaluate the optical performance of the LCD product. Since the optical simulation uses the random ray tracing technique, numerical noise may possibly be included in the simulation process. To solve the problem caused by numerical noise, the PQRSM which can stably find the solution of the noise problem is used in this research.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1555_1556
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• 2009

전자기기에서 외부 Console로 사용되는 Touch Pad의 입력오류를 줄이기 위해서는 안정된 전원의 공급이 필요하다, 전원에서 발생하는 노이즈는 PDN(Power Delivery Network)의 임피던스에 의해서 발생하며, 이들 노이즈를 줄이기 위해서는 decoupling capacitor의 적절한 수량과 위치를 선정하여, PDN의 임피던스를 최소화해야 한다. 본 논문에서는 임피던스의 최소화를 위해서 Full-wave 시뮬레이션을 이용해서 임피던스 특성을 분석하고, VNA(Vector Network Analyzer)를 이용하여 주파수에 대한 PDN 임피던스를 측정하고, Touch Pad 구동용 지그를 이용해서 Time Domain에서의 임피던스 저감에 따른 노이즈 특성을 분석 비교하였다.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.15 no.6 s.99
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• pp.660-666
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• 2005

Recently, the need for subminiature storage systems has increased with the diversification of portable devices. An actuator for small optical disk drives has to satisfy performance requirements such as higher access speed, lower power consumption, and smaller size. In this paper, we proposed the miniaturized rotary type VCM actuator that had an effective focusing mechanism and secured sufficient bandwidth for small form factor (SFF) optical disk drive (ODD). Initial model was designed by electromagnetic (EM) and structural analyses. Such a model was improved using design of experiments (DOE) procedure based on a Blu-ray disk (BD) 1x specifications.

• Journal of Information Display
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• v.7 no.4
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• pp.1-4
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• 2006

The optical performances of rounded prism films were investigated using a ray tracing technique. The angular distribution of the luminous intensity was obtained as functions of the prism pitch and the curvature of rounded apex and valley of prism arrays. The gain of the on-axis luminance decreased with decreasing curvature (increasing diameter) and pitch. The existence of the curved area on the prism film decreased the recycling efficiency of the prism film, i.e., the rays which would otherwise have been recycled through total internal reflections via the prism surfaces were refracted on the curved regions and redirected toward directions other than the on-axis direction. Quantitative correlation between the luminance gain and the curvature in addition to the prism pitch was obtained, which might serve as basic data for the optimization of prism films and the manufacturing processes.

• Transactions of the Society of Information Storage Systems
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• v.2 no.4
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• pp.219-223
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• 2006

Near field recording(NFR) technology has been considered as a strong candidate to surpass the far-field diffraction limit imposed by the nature of light in present optical disk drives such as CD, DVD, and BD(Blu-ray Disk). In this paper, we suggest novel inside near-field dual layer recording concept using elliptic shape solid immersion lens(ESIL).

• 정보저장시스템학회:학술대회논문집
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• 2005.10a
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• pp.217-221
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• 2005

Nowadays, HD(High Definition) broadcasting is popular all over the world. Many people want to record the HD level contents. BD(Blu-ray Disc) is developed to satisfy the needs. BD player for home movie system was manufactured already. ODD maker will produce BD Drive for PC(Personal Computer) within few months. Backward Compatibility is very important point in BD Drive. Until now, two OL(Object Lens), two optical pickup and two deck system are proposed. We suggest Single OL system in this paper. Single OL is composed of two optical parts and it's weight is heavy. We introduce the magnetic circuit composed of two 3-Pole magnets. In Spite of heavy OL, We achieve the New Actuator which has high performance.

• Proceedings of the Optical Society of Korea Conference
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• 2003.02a
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• pp.258-259
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• 2003

보호층 0.1mm두께의 20GB이상의 광디스크를 기록·재생하는 High Density Optical System에서는 Blue-violet laser와 NA(Numerical Aperture)0.85의 High NA의 대물렌즈를 사용한 Optical Pick Up이 필요로 된다. 종래의 대물렌즈는 glass 또는 plastic제의 2매 조합 대물렌즈가 많이 사용되어지고 있는데, 이는 두 렌즈간의 거리를 일정하게 유지시키기 위한 홀더 조립시의 공차가 엄격히 요구되며, 2매 조합 대물렌즈를 구동시키기 위한 actuator의 부피와 무게를 증가시킴으로서 구동감도를 감소시키는 단점이 있다. (중략)

• Transactions of the Society of Information Storage Systems
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• v.7 no.1
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• pp.13-18
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• 2011

As a standard of optical disk drive (ODD) was determined to Blu-ray diks (BD), researches for securing slim drive thickness, high data transfer rate and high capacity have been progressed. The actuator for applying BD is also required to have high performances, such as compatibility, slim thickness and 3-axis motion. In this paper, an asymmetric dual lens actuator is proposed to satisfy abovementioned performances. To design the actuator in a limited space, stress analysis and design of experiment (DOE) are performed to reduce weight of moving part and increase driving force and flexible mode frequency. Consequently, the final model, which is satisfied with specifications, is secured.

• Journal of the Korean Society for information Management
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• v.28 no.3
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• pp.103-121
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• 2011

This study is to seek to apply resource types of RDA to KCR4. It is difficult to choose appropriate term and to embody FRBR model because GMD of KCR4 is the mixture of content-based vocabularies and carrier-based vocabularies. SMD is to need to reflect the current technological terms. Resource type of RDA was already developed to overcome limitation of AACR2's GMD, and would affect the world cataloging environment, therefore it is need to apply resource type of RDA to Korean cataloging rule. For this study, case study and survey were used. In case study, it was to scan all GMD term for one university library to build by programming and to grape librarian and users' potential need. In the survey by cataloging librarian, it was to figure out the current description of resource type in university library and to test RDA resource type. As a result, it was needed to revise the vocabulary to the obvious and user-understandable list. Also it was different in correction rate in RDA testing by resource type. Based on the case study and the survey, RDA resource type was applied to KCR4 resource list by adding term such as computer game in content type, and by inserting terms such as DVD, CD-ROM, Blu-Ray, computer file in carrier type. It also applied RDA description method and display means to KCR4. This study would apply RDA resource type to KCR4 and contribute to revise KCR4 resource type.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.178-178
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• 2009

High-density optical information storing equipment, which is using Blu-ray, is the next generation information storing equipment that has about form six times to thirty-five times capacities. and high-density optical information storing equipment uses high NA(Numerical Aperture) aspheric glass objective lens as optical pick-up equipment to record and recognize high-density date. Generally this objective lens is developed and produced through a way of GMP(Glass Molding Press) that uses molding core that is performde by Ultra precision grinding, but grinding performing that has high-accuracy is very difficult because objective lens form is high NA. In this research, we preformed Ultra precision turning, using single crystal diamond bite, about WC(Co 0.5%), sintering brittleness material that is used molding core's material for GMP. and we confirmed aspheric glass lens compression of deformities molding core's Ultra precision turning possibility by measuring surface roughness(Ra) and processing surface's condition.