• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.20 no.3
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• pp.361-367
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• 2011

In this paper, it was attempted to analyze the optimal design of light emitting diode (LED), a source of back light unit (BLU). LED is beginning with commercialized red LED which is made by GaAsP compound semiconductor, and has been developed focusing on liquid crystal panel. In order to get the optimal design, optical simulation was made by analyzing luminosity shape, reflector angle, chip depth, and chip position of LED lighting. Final results show that the proposed LED characteristics were useful to increase light efficiency and it has been proven by distribution chart for actual exposed light on the light guide panel (LGP).

• Journal of the Korean Professional Engineers Association
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• v.42 no.5
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• pp.41-45
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• 2009

The last century of lighting has been dominated by incandescent, fluorescent and high-intensity discharge(HID)light sources. In the late 1970's, after green LEDs were invented, Dr. Ching Tang at Eastman Kodak discovered that sending an electrical impulse through carbon compound caused such material glow. Present day LED commercial packages have reached 100 lm/W, comparable to the efficacies of fluorescent and certain HID lamps. LED products available today are market as "Green-Industry" but actually low light output compared to typical light sources. The combination of high price and low light output make them a poor replacement for current technology. It is very important to compare new LED products to the most efficient conventional technology that could be used for any specific application. As LED technology advances, costs decrease, and efficiency improves, LEDs will build market share in the general illumination market.

• Science of Emotion and Sensibility
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• v.9 no.4
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• pp.353-366
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• 2006

The aim of this study is to characterize the optical properties of white light-emitting diodes lighting modules and then to evaluate the sensitivity of students and teachers in reacting to the optical properties of these modules. For the sake of this study, each of 5 lighting modules was introduced to the 5 test cabinets. The 5 test cabinets were evaluated and analyzed the student and teacher's sensitivity reaction. We have selected If questions on sensitivity of the lighting and evaluated these questions with semantic differential method. To verify the reliability and objectivity of the questions, the feasibility survey was carried out by a preliminary test. As a result of the test, the sensitivities on the test cabinets were classified the 4 factors, namely, activity as the first factor, stability as the second one , potency as the third one and sensitive image as the fourth one respectively. By the evaluation of student and teacher's sensitivity on the correlated color temperature, they preferred the cabinet with the higher color temperature in view of the activity and potency. And they preferred the cabinet with the lower color temperature in view of the stability factor. In the sensitive image, they preferred the 5800K, bluish white lighting regardless of the color temperature. By the evaluation on the color rendering index, they preferred the cabinet with the higher color rendering index in view of the activity, stability and sensitive image. In the potency factor, they preferred the white lighting with the middle color rendering index.

• Journal of Satellite, Information and Communications
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• v.10 no.4
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• pp.23-27
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• 2015

This paper, discusses about the implementation of the remote control LED Lights in elevator facility Since 1990, the elevator dissemination has greatly increasing. Currently in the elevator most of people they can use smart devices anytime or anywhere to view and retrieve the information by using internet. Therefore, in this paper, efficient management of power LED and LED remote control LED lighting fluid, in order to control features and smart devices can be applied to Web services platform and OS-specific proposals. Additionally based on the configured UI technology and programs offered by the present, and the LED lights are offered through the simulation to efficiently manage technology to demonstrate the usefulness.

• Journal of Advanced Navigation Technology
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• v.15 no.6
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• pp.1111-1117
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• 2011

We was designed the portable LED light which can shadowless shooting and developed using a high-power LED that medical attention as a new lighting components for structural confirmation of oral dental area, medical and surgical lesions in the local area. LED which applied to the development, was used the 3-color LEDs for possible of implement a variety of colors and adjusted the light intensity. It is being magnified of delicacy expressiveness and three-dimensional for tone of the subject-specific. It has been developed a highly efficient light module that LED is used to consider the electrical characteristics and optical properties. SMPS has We was designed the portable LED light which can shadowless shooting and developed using a high-power LED that medical attention as a new lighting components for structural confirmation of oral dental area, medical and surgical lesions in the local area. LED which applied to the development, was used the 3-color LEDs for possible of implement a variety of colors and adjusted the light intensity. It is being magnified of delicacy expressiveness and three-dimensional for tone of the subject-specific. It has been developed a highly efficient light module that LED is used to consider the electrical characteristics and optical properties. SMPS has produced for use in mobile that can be driven at low voltage. In addition, it was also possible to implement a variety of colors from monochromatic Light to polychromatic light using by PWM control method and were available 32,768.

• Journal of Satellite, Information and Communications
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• v.8 no.2
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• pp.17-21
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• 2013

A building energy-saving have been increased worldwide interest. There is continuing research on IT technology for efficient management of BEMS. Recently, It is able to control of LED and to maximize energy savings to the development of LED lighting technology. We propose the security image processing system to improve efficiency and we implement the real-time status monitoring system to surveil the object in the building energy management system. In this paper, we proposed the system of LED control using Zigbee network for connect the server. User is able to control LED light and monitering by the desktop. We implemented LED light control software on the based of Real-time monitering and LED control. Also detect human body movement.

• Journal of Power Electronics
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• v.16 no.4
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• pp.1288-1297
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• 2016

This study proposes a single-stage light-emitting diode (LED) tube lamp driver with input-current shaping for T8/T10-type fluorescent lamp replacements. The proposed AC-DC LED driver integrates a dual-boost converter with coupled inductors and a half-bridge series-resonant converter with a bridge rectifier into a single-stage power conversion topology. This paper presents the operational principles and design considerations for one T8-type 18 W-rated LED tube lamp with line input voltages ranging from 100 V rms to 120 V rms. Experimental results for the prototype driver show that the highest power factor (PF = 0.988), lowest input current total harmonic distortion (THD = 7.22%), and highest circuit efficiency (η = 92.42%) are obtained at an input voltage of 120 V. Hence, the proposed driver is feasible for use in energy-efficient indoor lighting applications.

• Journal of the Optical Society of Korea
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• v.18 no.5
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• pp.569-573
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• 2014

We demonstrate a low-cost, superbly efficient way of etching for the nano-, and micro-sized pyramid patterns on (100)-oriented Si wafer surfaces for use as a patterned master. We show a way of producing functional optical films for the viewing angle direction brightness-enhancement of Lambertian LED (light emitting diode)/OLED (organic light emitting diode) planar lighting applications. An optimally formulated KOH (Potassium hydroxide) wet etching process enabled random-positioned, and random size-distributed (within a certain size range) pyramid patterns to be developed over the entire (100) silicon wafer substrates up to 8" and a simple replication process of master patterns onto the PC (poly-carbonate) and PMMA (poly-methyl methacrylate) films were performed. Haze ratio values were measured for several film samples exhibiting excellent values over 90% suitable for LED/OLED lighting purposes. Brightness was also improved by 13~14% toward the viewing angle direction. Computational simulations using LightTools$^{TM}$ were also carried out and turned out to be in strong agreement with experimental data. Finally, we could check the feasibility of fabricating low-cost, large area, high performance optical films for commercialization.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.33 no.4
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• pp.79-84
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• 2010

In recent years, conventional streetlight is replaced by LED streetlight to reduce power consumption dramatically and to maximize lighting effects. However the characteristic of power LED itself driven by high current to increase the illumination, we need to develop effective heat release device. This study suggests new concept of heat dissipation device using PCM (Phase Change Material) and shows an experiment results to investigate thermal effects of PCM.

• Construction Engineering and Management
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• v.11 no.6
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• pp.66-69
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• 2010