• 제목/요약/키워드: Light Emitting diode

검색결과 1,401건 처리시간 0.026초

Development of Current Control System for Solar LED Street Light System

  • Kim, Byun-Gon;Kim, Kwan-Woong;Jang, Tae-Su;Lee, Jun-Myung;Kim, Yong-Kab
    • International journal of advanced smart convergence
    • /
    • 제1권1호
    • /
    • pp.52-56
    • /
    • 2012
  • As inexhaustible clean energy, solar energy will be the most ideal green energy in the 21st century. The effective method to convert solar energy into electrical energy is by solar photovoltaic power generation technologies. LED Emitting Diode is a kind of component which can transform electricity into visible light. As the smart current control system for photovoltaic street lights, the proposed system has improved the battery charging and discharging mechanism to extend the lifespan and effectively controls the LED discharge current according to battery charge state and lighting.

Postantibiotic Effects of Photodynamic Therapy Using Erythrosine and Light Emitting Diode on Streptococcus mutans

  • Yoo, Min Seok;Lee, Si Young
    • International Journal of Oral Biology
    • /
    • 제41권1호
    • /
    • pp.39-43
    • /
    • 2016
  • Dental caries, the most common oral disease, is a multifactorial disease caused by interactions among bacteria within the dental plaque, food, and saliva, resulting in tooth destruction. Streptococcus mutans has been strongly implicated as the causative organism in dental caries and is frequently isolated from human dental plaque. Photodynamic therapy (PDT) is a technique that involves the activation of photosensitizer by light in the presence of tissue oxygen, resulting in the production of reactive radicals capable of inducing cell death. Postantibiotic effect (PAE) is defined as the duration of suppressed bacterial growth following brief exposure to an antibiotic. In this study, the in vitro PAE of PDT using erythrosine and light emitting diode on S. mutans ATCC 25175 was investigated. The PAE of PDT for 1 s irradiation and 3 s irradiation were 1.65 h and 2.1 h, respectively. The present study thus confirmed PAE of PDT using erythrosine on S. mutans.

InGaN계 다중양자우물구조를 병렬 집적화한 백색광소자의 특성 연구 (White Light Emitting Diode with the Parallel Integration of InGaN-based Multi-quantum Well Structures)

  • 김근주;이기형
    • 반도체디스플레이기술학회지
    • /
    • 제3권4호
    • /
    • pp.39-43
    • /
    • 2004
  • The parallel multi-quantum well structures of blue and amber lights were designed and grown in metal-organic chemical vapor deposition by utilizing integration process on epitaxial layers. Samples were deposited for 5 periods-InGaN multi-quantum well layers for blue light emission and partially etched in order to regrow the 3 periods-InGaN multi-quantum wells for amber light. The blue and amber photoluminescence spectra were observed at the peak wavelengths of 475 and 580 nm, respectively. The chromatic coordinates of the white emitting diode were 0.31 and 0.34.

  • PDF

Wide Color Gamut Backlight from Three-band White LED

  • Kim, Il-Ku;Chung, Kil-Yoan
    • Journal of the Optical Society of Korea
    • /
    • 제11권2호
    • /
    • pp.67-70
    • /
    • 2007
  • A Wide Color Gamut Backlight system was studied using a three-band white Light-Emitting Diode. A three-band white light-emitting diode (LED) was fabricated using an InGaN-based blue LED chip that emits 445-nm blue peak, and a green phosphor and red phosphor that emit 535-nm green and 621-nm red peak emissions, respectively, when excited by 450-nm blue light. Using for this three-band white LED, wide color gamut backlight unit (BLU) was attained. The luminance of BLU and CIE 1931 chromaticity coordinates was $1,700Cd/m^2$ and (0.337, 0.346). Color filter matching simulations for this configuration show that the three-band white LED backlight can be enhanced by up to 16% over conventional white LED backlight color gamut.

Dentin shear bond strength and degree of conversion of the dentin bonding agents irradiated with light emitting diode

  • Kim, Sun-Young;Um, Chung-Moon
    • 대한치과보존학회:학술대회논문집
    • /
    • 대한치과보존학회 2003년도 제120회 추계학술대회 제 5차 한ㆍ일 치과보존학회 공동학술대회
    • /
    • pp.576-577
    • /
    • 2003
  • I. Objectives This study investigated the dentin shear bond strength and the degree of conversion (DC) of currently used dentin bonding agents (DBAs) that were irradiated with a light emitting diode (LED) light curing unit (LCU) and a halogen LCU. II. Materials and methods The halogen LCU and the LED LCU used in this study were a VIP(Bisco, Schaumburg, IL, USA) and an Elipar Freelight(3M ESPE, St Paul, MN, USA) respectively. For the VIP, $400mW{\cdot}cm-2$ intensity mode was used to adjust to the intensity of the LED LCU. The DBAs used in this study were Scotchbond Multipurpose (3M ESPE), Single Bond (3M ESPE), One-step(Bisco), Clearfil SE Bond(Kuraray), and Adper Prompt(3M ESPE).(omitted)

  • PDF