Xe 평판형 플라즈마 광원에서 전기광학적 특성

이경섭,문종대,최용성 동신대학교 2006 論文集 Vol.16 No.-

The flat panel lamp is used as back light. It is perceived the best type for the wide size LCD of back light system. However, the flat panel lamp has high value of heat. So it need to improve efficiency. Therefore, more researches are requested for the back light of the flat panel lamp. In this paper, the properties of spectrum is investigated according to change in frequency from 30kHz to 60kHz using power supplies voltage with changing from 500V to 700V. As a result, main spectrum peak of plasma showed in 450[nm], 630[nm], 750[nm] and spectrum peak of 750nm is the highest. Discharge of the flat lamp lighting source research are requested very much. For improving brightness, life time, efficiency of flat lamp and plasma diagnosis of the flat lamp lighting source to understand property of lighting source is very important. When a distance of discharge electrode is 5.5mm and width is 16.5mm, we measured electron temperature and electron density measured with single Langmuir probe in flat lamp. We tested the discharge from 100 Torr to 300 Torr pressure. The pulse type was rectangular with frequency 20kHz and duty ratio was 20%.

대향형 Xe 플라즈마 평판 램프의 방전 및 발광 특성에 관한 수치적 연구

김혁환,이원종,Kim, Hyuk-Hwan,Lee, Won-Jong 한국전기전자재료학회 2011 전기전자재료학회논문지 Vol.24 No.10

A Xe plasma flat lamp, which has been noticed as a new eco-friendly LCD (liquid crystal display) backlight, requires the improvement of the luminance and the luminous efficiency although it has several advantages. To improve the performance of a lamp, it is necessary to understand the effects of discharge variables on the luminous characteristics of the lamp. Since it is difficult to diagnose a lamp discharge experimentally, the numerical analysis can be used instead. In this study, the luminous characteristics of a planar type Xe plasma flat lamp were analyzed with the variation of an input voltage and a pulse frequency. The numerical analysis of a lamp discharge was then performed using a RCT (relaxation continuum) model and a LFA (local field approximation) model. The comparison with the experimental results showed that the RCT model is valid for the numerical analysis of the flat lamp. The numerical analysis also showed that the modifications of a high frequency component and a voltage falling rate in the input voltage waveform could improve the luminous characteristics of the lamp.

면방전형 Xe 플라즈마 평판 램프의 방전 및 발광 특성

김혁환,이원종,Kim, Hyuk-Hwan,Lee, Won-Jong 한국재료학회 2011 한국재료학회지 Vol.21 No.10

The Xe plasma flat lamp, considered to be a new eco-friendly LCD backlight, requires a further improvement of its luminance and luminous efficiency. To improve the performance of this type of lamp, it is necessary to understand the effects of the discharge variables on the luminous characteristics of the lamp. In this study, the luminous characteristics of a coplanartype Xe plasma flat lamp with a teeth-type electrode pattern were analyzed while varying the gas composition, gas pressure and input voltage. The effects of the phosphor layer on the discharge and the luminous characteristics of the lamp were also studied. The luminous efficiency of the coplanar-type Xe plasma flat lamp improved as the Xe input ratio and gas pressure increased. Higher luminous efficiency was also obtained when helium (He) was used as a buffer gas and when a phosphor layer was fabricated on the electrode region. In contrast, the luminous efficiency was reduced with increasing the input voltage. It was found that the infrared emissions from the lamp were affected by the Xe excitation rate in the plasma, the Xe gas density, the collisional quenching of excited Xe species by gas molecules, and the recombination rate between the Xe ions and electrons.

Performance Evaluation of 2-Dimensional Light Source using Mercury-free Flat Fluorescent Lamps for LCD Backlight Applications

Joung-Hu Park,Bo-Hyung Cho,Ju-Kwang Lee,Ki-Woong Whang 전력전자학회 2009 JOURNAL OF POWER ELECTRONICS Vol.9 No.2

Recently, 2-dimensional flat light sources have been attracting much attention for its use in LCD backlight applications because of its high luminous efficiency and uniformity. A long-gap discharge, mercury-free flat fluorescent lamp has been developed, which shows a high brightness (>5000 cd/㎡) and high luminous efficacy (60 lm/W). Additionally, it has a wide operating margin and stable driving condition with the aid of an auxiliary electrode. For driving the lamp, a narrow pulse power to maintain the glow discharge state is required. Since there has been no research for this kind of lamp driving, this paper proposes a newly developed short-pulse, high-voltage lamp-driving scheme. The proposed lamp system uses a ballast with a coupled-inductor in order to raise the short pulse voltage up to the lamp ignition level and to obtain energy-recovery action during the glow discharge mode. The operation principles are presented and also the system performances such as the lighting efficiency, spatial and angular uniformities are evaluated by hardware experiments. The results show that the proposed lighting system is a good candidate for the next-generation of LCD backlight systems.

Performance Evaluation of 2-Dimensional Light Source using Mercury-free Flat Fluorescent Lamps for LCD Backlight Applications

Park, Joung-Hu,Cho, Bo-Hyung,Lee, Ju-Kwang,Whang, Ki-Woong The Korean Institute of Power Electronics 2009 JOURNAL OF POWER ELECTRONICS Vol.9 No.2

Recently, 2-dimensional flat light sources have been attracting much attention for its use in LCD backlight applications because of its high luminous efficiency and uniformity. A long-gap discharge, mercury-tree flat fluorescent lamp has been developed, which shows a high brightness ($>5000\;cd/m^2$) and high luminous efficacy (60 lm/W). Additionally, it has a wide operating margin and stable driving condition with the aid of an auxiliary electrode. For driving the lamp, a narrow pulse power to maintain the glow discharge state is required. Since there has been no research for this kind of lamp driving, this paper proposes a newly developed short-pulse, high-voltage lamp-driving scheme. The proposed lamp system uses a ballast with a coupled-inductor in order to raise the short pulse voltage up to the lamp ignition level and to obtain energy-recovery action during the glow discharge mode. The operation principles are presented and also the system performances such as the lighting efficiency, spatial and angular uniformities are evaluated by hardware experiments. The results show that the proposed lighting system is a good candidate for the next-generation of LCD backlight systems.

Study on the Luminance Properties of Optical Films for Flat-lamp Backlight Applications

Mi-Yeon Yu,Ji-Hee Park,고재현 한국광학회 2008 Current Optics and Photonics Vol.12 No.3

The luminance properties of FFL(Flat Fluorescent Lamp) backlights have been investigated in detail for the first time. The on-axis luminance gain as well as viewing-angle characteristics on various combinations of optical films were obtained from FFL backlight and compared to the results of conventional CCFL(cold-cathode fluorescent lamps) backlights. It was found that the on-axis luminance gains achieved by using optical films in the FFL backlight were lower than those in the CCFL backlight indicating that the recycling processes occurring between optical films and light sources/reflection sheet are not so effective in the FFL backlight due to the much larger area of, and thus higher absorption probability of the FFL. This result suggests that new optical films should be developed for FFL backlight and other flat-lamp backlight technologies.

유리기판 위에 성장된 탄소나노튜브를 이용한 평판 램프의 전계방출 특성

이양두,문승일,한종훈,이윤희,주병권,Lee, Yang-Doo,Moon, Seung-Il,Han, Jong-Hun,Lee, Yun-Hi,Ju, Byeong-Kwon 한국전기전자재료학회 2004 전기전자재료학회논문지 Vol.17 No.6

We fabricated the 1-inch diode type flat lamp using CNTs, which were grown directly on soda-lime glass substrate at 600 ∼ 650 $^{\circ}C$ by thermal chemical vapor deposition(CVD) of acetylene gas. Turn- on field was about 2.8 V/${\mu}{\textrm}{m}$. We observed that uniform and high brightness had been obtained. The brightness of CNT flat lamp was measured up to about 14 kcd/$m^2$ at 2000V in spacing of 500 ${\mu}{\textrm}{m}$. The results showed that the CNTs were very good emission source and suitable for application in the lamp.

평면 LED 램프에서의 초음파 센서의 반사특성을 고려한 위치측정 기법

허영록(Young-Rok Heo),윤장희(Jang-Hee Yun),염정덕(Jeong-Duk Ryeom) 한국조명·전기설비학회 2013 조명·전기설비학회논문지 Vol.27 No.12

In this paper, the location measurement method for the reliable location data using ultrasonic sensors is proposed for the dimming control of the LED flat lamp. The measurement errors depending on the reflection angle of the object have to be considered to obtain the reliable location data in the ultrasonic sensors. In the experiment, the cause of the measurement errors depending on reflection angle is analyzed and velocity change of ultrasonic wave depending on reflection angle is measured. And the location measurement method depending on velocity change of ultrasonic wave is proposed. From the results, the average absolute deviation of the x-coordinates was 1.47cm when the location measurement method was considered, and it was closer to the true values than the average absolute deviation of the x-coordinates which was 5.89cm without regard to the reflection angle.

면광원을 이용한 32" 조명등 개발

임성규,Lim, Sung-Kyoo 한국반도체디스플레이기술학회 2010 반도체디스플레이기술학회지 Vol.9 No.1

A flat luminaire utilizing 32" flat fluorescent lamp was developed and its optical characteristics were compared with that of the troffer using three T8 regular fluorescent tubes. The optical characteristics of the 32" flat luminaire was similar to that of the troffer.

면광원 램프 및 이를 이용한 조명 기기의 효율 특성 연구

박종리,임성규,Park, Jong-Lee,Lim, Sung-Kyoo 한국조명전기설비학회 2007 조명·전기설비학회논문지 Vol.21 No.7

LCD(liquid crystal display) TV용 백라이트의 광원으로서 면광원이 개발되었으며, 이를 이용한 조명 기기를 제작 및 평가하였다. 면광원은 유리성형을 통하여 채널을 형성하였으며 채널의 모양을 최적화하여 면광원을 이용한 조명 기기의 효율을 향상시킬 수 있었다. 본 논문에서는 특히 현재 주로 사용되고 있는 형광등과의 비교 평가를 통하여 조명용 면광원의 광 효율 및 조도 특성에 관한 성능을 평가하였다. 채널의 구조가 최적화된 면광원을 이용하여 제작된 32"형 조명 기기의 광 효율은 72.7[1m/W]이었다. A flat fluorescent lamp (FFL) developed as a light source for LCD TV backlight was used as a light source for general lighting application and its electro-optical characteristics were measured and evaluated. The channels of FFL were formed from a flat glass at high temperature by using a mold. The performance of FFL with lighting future was shown to improve by optimizing the channel profile of FFL. In this paper, the brightness efficiency of FFL with lighting fixture was evaluated and compared with that of the hot cathode fluorescent lamp (HCFL), the major light source for general lighting. The optical efficiency of FFL with future was shown to be 72.7[1m/W].