• Journal of Magnetics
• /
• 제20권1호
• /
• pp.57-61
• /
• 2015

In this paper wireless power transmission system based on magnetic resonance coupling circuit was carried out. With the research objectives based on the mutual coupling model, mathematical expressions of optimal coupling coefficients are examined. Equivalent circuit parameters are calculated by Maxwell software, and the equivalent circuit was solved by Matlab software. The power transfer efficiency of the system was derived by using the electrical parameters of the equivalent circuit. System efficiency was analyzed depending on the different air gap values for various characteristic impedances. Hence, magnetic resonance coupling involves creating a resonance and transferring the power without radiating electromagnetic waves. As the air gap between the coils increased the coupling between the coils were weakened. The impedance of circuit varied as the air gap changed, affecting the power transfer efficiency.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2002년도 하계학술대회 논문집 C
• /
• pp.1964-1965
• /
• 2002

This paper reports on the single mode fiber coupling efficiency. There is difference between simulation by CODE-V and theoretical result, we observed CEO which is taken by experiment in lab and found out that CEO taken by CODE-V was closer to real experiment result then theoretical result.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2004년도 추계학술대회 논문집
• /
• pp.840-843
• /
• 2004

UV molding is a process for integrating micro/nano polymeric optical components on optoelectronic modules. In the present study, a microlens array for vertical cavity surface emitting laser(VCSEL) to fiber coupling was designed, integrated and tested. At the design stage, design variables ware optimized to maximize the coupling efficiency, and tolerance analysis was carried out. At the integration stage, the UV transparent mold was fabricated and the microlens array on VCSEL array was integrated by UV molding process. Finally the coupling efficiency of VCSEL to fiber was measured and analyzed.

• 전기전자학회논문지
• /
• 제23권2호
• /
• pp.747-750
• /
• 2019

웨어러블 디바이스는 일상생활에서 실질적으로 필수적이며 사용자들에게 편리하게 이용되고 건강관리와 의학 분야 등에 활용되고 있다. 전력분야에서 전원 배터리의 사용시간의 한계를 극복하고 효율적인 충전방법에 관한 많은 연구가 진행되고 있다. 무선전력전송은 전선을 사용하지 않고 무선으로 전기장을 부하에 전력을 전달하는 기술이다. 이 전송기술은 저 전력의 스마트폰에서부터 고 전력을 사용하는 철도 충전시스템까지 응용분야가 다양하다. 충전방식은 유도방법과 자기공진방법의 2 종류로 나누는데 자기공진주파수는 13.45 Mhz를 사용하였다. 본 연구에서는 전송효율을 측정 비교하기 위하여 2 종류의 하드웨어를 구현한 후 비교하는데 있다.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
• /
• pp.625-628
• /
• 2004

Porous anodic alumina(PAA) which has arrays of nano size holes, was incorporated into organic light emitting devices. Porous anodic alumina on glass scattered the light generated from emitting layer and was decreased the waveguiding modes within the glass. An increase in the device coupling-out factor for the scattering structure is demonstrated.

• 반도체디스플레이기술학회지
• /
• 제21권2호
• /
• pp.7-10
• /
• 2022

A functional polyethylene terephthalate substrate to increase light extraction efficiency of organic light-emitting diodes is studied. We formed nano-structured PET surfaces by controlling the power, gas, and exposure time of the linear ion-beam. The haze of the polyethylene terephthalate can be controlled from 0.2% to 76.0% by changing the peak-to-valley roughness of nano structure by adjusting the exposure cycle. The treated polyethylene terephthalate shows average haze of 76.0%, average total transmittance of 86.6%. The functional PET increases the current efficiency of organic light-emitting diodes by 47% compared to that of organic light-emitting diode on bare polyethylene terephthalate. In addition to polyethylene terephthalate with light extraction performance, by conducting additional research on the development of functional PET with anti-reflection and barrier performance, it will be possible to develop flexible substrates suitable for organic light-emitting diodes lighting and transparent flexible displays.

• 한국광학회지
• /
• 제19권1호
• /
• pp.31-35
• /
• 2008

결합효율이 높고 정렬오차 발생 시 결합효율의 저하가 작은 광통신용 비구면 렌즈 시준기를 설계하였다. 비구면 시준 렌즈는 GRIN 렌즈와 작동거리와 두께가 유사하고 외경이 동일한 원통형 막대 형태로 설계해 GRIN 렌즈를 대체할 수 있도록 하였다. 결합효율의 저하는 시준렌즈의 구면수차에 의해 주요하게 발생하므로, 비구면 렌즈 시준기가 볼 렌즈, GRIN 렌즈 및 C-렌즈 시준기보다 높은 결합효율을 가지도록 비구면 계수를 최적화 해 구면수차를 낮추었다. 설계한 비구면 렌즈 시준기의 결합효율은 기존 시준기들보다 높았으며 정렬오차에 따른 결합효율의 감소도 작았다.

• Journal of Information Display
• /
• 제13권4호
• /
• pp.151-157
• /
• 2012

A simple method of fabricating out-coupling structures was demonstrated via solution-processing to enhance light extraction from organic light-emitting diodes (OLEDs). Scattering layers were easily obtained by spin-coating an $SiO_2$ sol solution that contained $TiO_2$ particles. By introducing the scattering layer and the solution-processible corrugated structure as internal and external extraction layers, the OLEDs showed increased external quantum efficiency without a change in the electroluminescence spectrum compared to conventional devices. Using these solution-processible out-coupling structures, nearly all-solution-processed OLEDs with enhanced light extraction could be fabricated. The light extraction enhancement is attributed to the suppression by the out-coupling structures of the light-trapping that arose at the interface of the glass substrate and the air.

• 한국광학회:학술대회논문집
• /
• 한국광학회 2008년도 하계학술발표회 논문집
• /
• pp.321-322
• /
• 2008

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
• /
• pp.1591-1594
• /
• 2006

In this work, we fabricated efficient white organic light emitting device (WOLED) by the stack of complementary fluorescent dye-doped layers, Effect of dye-doping ratio and thickness of each layers on WOLED efficiency and emission spectrum was investigated. Moreover, out-coupling efficiency enhancement using microlens array was analyzed for bottom and top-emitting device architecture, leading to higher light extraction properties.