• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.5
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• pp.26-33
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• 2015

Secondary optical system designed for LED bulb which emits light in all directions was simulated with Energy Star standards. Components of the optical system were LED light source, the cover of the LED bulb and reflector which is to confirm the diffuser plate and LightTools software was used to design the illumination optics. The main points of the secondary optical system design are the location of the LED light source, the shape of the LED bulb cover, the location of the reflection plate, and the scattering properties of the diffusing plate. Mechanism of the LED bulb is that the light emitted from the light source move on to the backward after reflected by the coated light cover from the inside and then the reflected light is scattered by the diffuser plate. The LED bulb was designed to satisfy the standard light distribution and color specifications of the Energy Star(IES LM-79-08).

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.22 no.3
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• pp.480-487
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• 2013

In this study, we researched the LED source MR16,which maintains the strong points of an ordinary MR16 while compensating for its weak points. The optical system composition of the LED MR16 includes four aspherical lens per sheet and a patterned reflector. The aspherical optical system and reflector were designed using optical software, and the performance was estimated using a lighting simulation program. Finally, a prototype was manufactured after analyzing the simulation data, and the reliability of the simulation results was estimated using a comparative analysis of the designed data and measured data.

• 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.

• Current Optics and Photonics
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• v.1 no.3
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• pp.233-238
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• 2017

In this paper we propose a freeform secondary lens for an LED fishing/working lamp (LFWL). This innovative LED lamp is used to replace the traditional HID fishing lamp, to satisfy the lighting demands of fishing and the on-board activities on fishing boats. To realize the freeform lens's geometry, Gaussian decomposition is involved in our optics-design process for approaching the targeted light intensity distribution curve (LIDC) of the LFWL lens. The simulated results show that the illumination on the deck, on the sea's surface, and underwater shows only small differences between LED fishing/working lamps and HID fishing lamps. Meanwhile, a lighting efficiency of 91% with just one third of the power consumption can be achieved, when the proposed LED fishing/working lamps are used instead of HID fishing lamps.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.11
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• pp.14-25
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• 2011

Full-Color LED lighting system requires efficient control of the lighting color in order to easily achieve various color effects. In this paper, we present not only a portable color scanner using color sensors which can control lighting color directly from detected color but also methods to convert detected color to a complementary color, similar colors and so on. In addition, we propose a compensation method for measured sensor color to reduce measurement errors more than 50[%] in detected color. The developed color scanner is applied to control full-color LED ceiling light for emotional lighting.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2009.05a
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• pp.243-247
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• 2009

A Radioactive constraint of the nuclear fuel assembly irradiated by neutron during normal operation cycle of the nuclear power plant is typically on the order of about 3 kGy/h. In order to inspect nuclear fuel assembly using a VT (vision technology) system, the light such as halogen lamp is used. As the halogen lamp has lower color temperature than the sun light, the objects under halogen lamp illumination are seemed to be tinted with red. In this paper, high brightness LED is considered to be used as the light source of VT system. The high brightness LED, which is a key light source of the VT system, have been gamma irradiated at the dose rate of 4 kGy/h during two hours up to a total dose of 8 kGy. The radiation induced color-center in the LED housing cap made of plastics materials is observed.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.1379-1382
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• 2009

The 3D display has been used in optical projection technology to connect twenty mini- projectors with seamless image tiling. In this way, we can improve the projected resolution by reducing each project screen and increase projected area by connect several mini-projectors. In this article, the illumination system uses the LED light source, non- telecentric structure and LCOS panel, and it's total length is less than 10 centimeter. It can build a seamless large display by tiling multiple projectors.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.2
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• pp.284-288
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• 2015

The color temperature flexibility-typed Lighting Emitting Diode(LED) lighting control system proposed in this thesis employs Pulse Width Modulation(PWM) technique to control the brightness of LED lighting. The LED lighting used as a light source has 20W downlight composed of two types of LED chips: one is Warm White and the other is Cool white. One multi-sensor module consisting an infrared sensor, an illumination sensor, and a temperature sensor was made, to which Bluetooth wireless communication technique was applied to enable a smartphone application to control lighting brightness and identify the information collected from the sensor. CS-1000, a spectroradiometer, was used to measure LED dimming control and the changing values of a color temperature in eight steps. According to a test, it was found that it was possible to change a color temperature from 3187K of Warm White LED to 5600K of Cool White LED.

• Journal of Advanced Marine Engineering and Technology
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• v.34 no.8
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• pp.1100-1106
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• 2010

LED(Light Emitting Diode) has the defects of low efficiency and reducement of life cycle as its temperature increases. This research is about an efficient temperature control of the LED. For LED temperature control, it is shown that a heat sink, fan, a one-chip microprocessor and the PID control algorithm are a good cooling system through experiments. Finally. by using the fan as a cooling device and controlling it appropriately, it is proved that the intensity of illumination and the desired temperature can be achieved with consumption of only 2% of the driving power of the LED system through control experiments.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.28 no.1
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• pp.64-68
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• 2015

In this paper, LED lighting system is realized by using Bluetooth wireless communications and smartphones. A bluetooth module with a lighting control function is manufactured by miniaturizing a development board of TI company and the volume of LED dimming system as a whole is reduced. And a trial product is materialized by designing a hardware composed of the manufactured bluetooth module, LED down light equipped with degree warm white and cool white, and 2-channel LED driver; and LED dimming software. The materialized trial product is controled in terms of the brightness and color temperature of LED light source using an application of a smartphone. The experiment showed that the users can easily control the intensity of illumination of LED light source by using the scroll bar of the applications of smartphones. In addition, the color temperatures of both warm white and cool white can be controlled, and when the color temperature of the trial product using the manufactured bluetooth module is compared with that of a trial product of TI company, they show the same color temperatures.