• 전력전자학회논문지
• /
• 제14권1호
• /
• pp.8-14
• /
• 2009

현재 사용하고 있는 LCD(Liquid Crystal Display) Backlight용 램프는 주로 CCFL(Cold Cathod Fluorescent Lamp)과 EEFL(External Electrode Fluorescent Lamp)이 사용되고 있다. 하지만 이 램프는 수은을 사용하여 RoHS(the Restriction of e use of certain Hazardous Substances in electrical and electronic equipment)규제가 점점 강화되면서 사용이 제한되고 있으며, 이에 따라 수은을 사용하지 않는 램프의 제작이 불가피해지고 있다. 또한 LCD TV는 CRT와 PDP와는 다른 LCD만의 Hold-type 특성과 LC(Liquid Crystal)의 응답속도로 인하여 Motion Blur현상이 나타나는 단점이 있다. 본 논문에서는 RoHS 규제를 만족시키는 무수은 면광원 램프를 구동하기 위한 인버터를 제안한다. 제안한 인버터는 포워드 방식을 사용하여 반도체 소자 및 자기 소자의 수를 줄여서 구동회로가 간단하다. 또한 면광원 램프를 세로방향으로 6블록으로 나누어 스캔구동을 하여 Motion Blur현상을 저감 시켰다. 끝으로 실험을 통하여 제안한 인버터의 유용성을 입증하였다.

• 조명전기설비학회논문지
• /
• 제25권4호
• /
• pp.16-23
• /
• 2011

Since the first lighting light source was invented, lighting has turned into superior-quality lighting considering the amenity of occupants, and the characteristics of a light source has developed rapidly. So this research confirmed the lighting performance of a dimmer control system and an ON-OFF control system via the existing light source, and analyzed the basic lighting environment of Permanent Supplementary Artificial Lighting of Interiors(PSALI) through the physical comparison and evaluation of a LED lamp substituted for a fluorescent lamp used in a dimmer control system, showing that the lighting physical quantity characteristics of an ON-OFF control system and a dimmer control system are similar to each other and that they are effective in terms of energy saving. Besides, it was shown that introducing a LED light source to a dimmer control system improves lighting environments and largely reduces energy consumption.

• 원예과학기술지
• /
• 제30권6호
• /
• pp.673-679
• /
• 2012

본 실험은 밀폐형 식물생산시스템에서 인공광원과 광조사 시간에 따른 잎상추 '선홍적축면' 품종의 적정 생육 조건을 구명하고자 수행하였다. 상추 유묘를 3종류의 인공광원인 형광등과 에프씨 포이베(사)와 헤파스(사)의 백색 LED 아래에서 재배하였고, 광조사 시간을 각각 12/12, 18/6, 24/0(명기/암기)으로 처리하였다. 광파장대를 측정한 결과 형광등은 400-700nm 범위에서 다양한 피크를 나타냈지만, 2종류의 백색 LED에서는 450nm와 550nm의 파장대역에서만 피크를 나타냈다. 초장, 생체중 및 건물중은 광조사 시간을 24/0(명기/암기)으로 처리하였을 때 가장 우수했다. 또한 엽면적도 광조사 시간 24/0(명기/암기) 처리구에서 좋았다. 형광등 처리가 2종류의 백색 LED와 비교하여 최대근장, 엽수, 생체중 및 총 안토시아닌 함량이 우수하였다. 엽록소 형광값은 형광등을 사용하여 광조사 시간을 12/12(명기/암기)로 처리하였을 때 가장 높았다. 형광등 광원에서 광 에너지 사용 효율은 LED 등이 형광등과 비교하여 약 35-46% 더 높았다. 본 결과는 식물공장 시스템에서 상추 재배를 위한 형광등의 대체 광원으로써 LED의 이용가능성을 보여 주었다.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
• /
• pp.1725-1728
• /
• 2006

Flat fluorescent lamp(FFL) is used as a light source for LCD TV backlight and is composed of many discharge channels but each channel may not be turned on simultatneouly especially at cold temperature. The simultaneous start of each lamp channels of FFL was accomplished by driving FFL with specially designed voltage and currnet waveforms without sacrificing the inverter efficency.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2006년도 추계학술대회 논문집 광주전남지부
• /
• pp.75-78
• /
• 2006

An external electrode fluorescent lamps (EEFLs) have the advantage of a long lifetime in the early stages of the study on plasma discharge, interest in the lamp continues. Studies on the operation of external electrode fluorescent lamps have focused mainlyon its use of a type of high frequency (MHz). By performing high brightness using a square wave operation method with the low frequency below 100kHz, which is applied to a narrowed tube type lamp that has several mm of lamp diameter, an EEFL presented the possibility of using it as a light source for backlights. However, because an EEFL generates plasma using wall charges, which considers the impedance characteristics of glass based on the structural principle in discharge, it can be significantly affected by frequency. Thus, this study verifies the change in the characteristics of electromagnetic fields according to the change in frequency through a Maxwell's electromagnetic field simulation and examines the relationship between the change in the EEFL frequency and brightness by measuring the optical. characteristics. In addition, the characteristics of the transformation of energy orbits were verified by investigating the characteristics of the wavelength according to the change in frequency through the OES.

• 한국지반환경공학회 논문집
• /
• 제13권10호
• /
• pp.63-68
• /
• 2012

본 연구는 해양미세조류의 일종인 Isochrysis galbana를 다양한 파장의 발광다이오드를 이용하여 배양한 후 최적 파장을 찾아내고, 최적파장을 광원으로 하여 회분식 실험에서의 대량 배양 조건을 찾기 위해 수행되었다. I. galbana 배양에 가장 효율적인 파장은 백색 LED였으며, 백색 LED의 광도에 따른 실험을 통해 3,000Lux의 광도가 본 미세조류의 성장에 최적임을 알 수 있었다. 형광등과의 비교 실험 시 같은 광도에서 백색 LED가 미세조류의 배양에 있어 10% 정도 높은 효율을 나타내었다. 배양이 진행되어 셀 농도가 증가하면서 발생하는 그림자 효과를 상쇄시키기 위해 공기 공급을 하였으며, 4가지 조건의 공기 공급 속도에서 모두 비슷한 성장특성을 보여주었다. 공기를 주입한 경우 주입하지 않은 경우보다 최대 3배 이상 균체 농도가 증가하였다.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2006년도 전력전자학술대회 논문집
• /
• pp.206-209
• /
• 2006

At present, the cold cathode fluorescent lamp (CCFL) using mercury lamp has been generally used far liquid crystal backlight source of personal computer and car navigation and so on. This kind of lamp is more excellent on luminance performance and cost. However, the requirements of liquid crystal backlight due to a light source without mercury have been strongly increased from a viewpoint of the actual influence on environmental preservation and environmental recycling. As fluorescent lamp without mercury, Dielectric Barrier Discharge based rare gas fluorescent lamp (DBD-FL) using xenon (Xe) gas has been studied so far. This DBD lamp has no influence on the human body and environmental recycle. Its operating life is long because electrode is out. In this paper, the simulation and experimental results of soft switching high frequency inverter with reverse blocking single switch as a high frequency power supply circuit for DBD-FL using Xe gas are comparatively evaluated and discussed from a practical point of view.

• Korean Chemical Engineering Research
• /
• 제43권1호
• /
• pp.170-175
• /
• 2005

자외선을 대체하여 형광등이나 자연광(햇빛)을 이용하여 $TiO_2$로 수은제거 실험을 수행하였다. 반응기는 내부의 $TiO_2$가 광원에 최대한 노출되도록 디자인하였으며 회전할 수 있게 하였다. 반응기 내부에 $TiO_2$와 유리비드를 섞어 넣어 기상수은과 흡착제와의 접촉면적을 최대화하였다. 광촉매가 가장 활성을 잘 보이는 UV black light뿐 아니라 실험에 사용된 모든 광원에서 99% 이상의 수은제거효율을 보였다. 인체에 무해하고 경제성이 좋은 형광등이나 태양광하에서도 99% 이상의 수은제거효율을 얻었다.

• 한국약용작물학회지
• /
• 제28권3호
• /
• pp.200-208
• /
• 2020

Background: Salvia miltiorrhiza Bunge has been used in traditional medicine. The type of light source has an effect on the growth properties and composition of functional compounds in plants. In this study, we analyzed the effects of different artificial light sources on the growth characteristics as well as antioxidant and antimicrobial activities of S. miltiorrhiza. Methods and Results: Seedlings of S. miltiorrhiza were grown under various artificial light sources, including fluorescent light (FL), light emitting diode (LED), and microwave electrodeless light (MEL), for 8 weeks. Growth characteristics were the best in plants treated with MEL. DPPH scavenging activity of the shoot was more pronounced with the FL treatments, while the roots were more active in plants grown under single wavelength lights (i.e., blue and red LEDs). Among the different light source treatments, the blue LED resulted in a higher total phenolic content in the plants. Furthermore, growing plants growth under the red LED enhanced their total flavonoid content. Notably, the antimicrobial properties of plants varied significantly between light source treatments in this study. Except for E. coli, all the tested microorganisms were susceptible to the plant extracts. Conclusions: The type of light source may be an important parameter for the enhancement of plant growth and functional compounds in S. miltiorrhiza.

• Journal of Biosystems Engineering
• /
• 제38권4호
• /
• pp.279-286
• /
• 2013

Purpose: This study was conducted to analyze the utilization efficiencies of electric energy and photosynthetically active radiation of lettuce grown under red LED, blue LED and fluorescent lamps with different photoperiods. Methods: Red LED with peak wavelength of 660 nm and blue LED with peak wavelength of 450 nm were used to analyze the effect of three levels of photoperiod (12/12 h, 16/8 h, 20/4 h) of LED illumination on light utilization efficiency of lettuce grown hydroponically in a closed plant production system (CPPS). Cool-white fluorescent lamps (FL) were used as the control. Photosynthetic photon flux, air temperature and relative humidity in CPPS were maintained at 230 ${\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, $22/18^{\circ}C$ (light/darkness), and 70%, respectively. Electric conductivity and pH were controlled at 1.5-1.8 $dS{\cdot}m^{-1}$ and 5.5-6.0, respectively. The light utilization efficiency based on the chemical energy converted by photosynthesis, the accumulated electric energy consumed by artificial lighting sources, and the accumulated photosynthetically active radiation illuminated from artificial lighting sources were calculated. Results: As compared to the control, we found that the accumulated electric energy consumption decreased by 75.6% for red LED and by 70.7% for blue LED. The accumulated photosynthetically active radiation illuminated from red LED and blue LED decreased by 43.8% and 33.5%, respectively, compared with the control. The electric energy utilization efficiency (EEUE) of lettuce at growth stage 2 was 1.29-2.06% for red LED, 0.76-1.53% for blue LED, and 0.25-0.41% for FL. The photosynthetically active radiation utilization efficiency (PARUE) of lettuce was 6.25-9.95% for red LED, 3.75-7.49% for blue LED, and 2.77-4.62% for FL. EEUE and PARUE significantly increased with the increasing light period. Conclusions: From these results, illumination time of 16-20 h in a day was proposed to improve the light utilization efficiency of lettuce grown in a plant factory.