• The Optical Journal
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• s.135
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• pp.38-42
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• 2011

이 원고는 Toshiba Lighting&Technology(주) LED사업부 LED기술총괄부 LED광원기술부 광원기술 제2담당인 오가와 코우조우씨가 월간 Optronics(통권 349호)에 기고한 내용이다. 본고에서는 현재 급속히 보급이 확대되고 있는 백열전구치환의 LED전구 LED유닛과 업계 최초로 HID램프사용 Downlight 치환의 LED Downlight에 대해서 LED조명보급을 위한 제품 콘셉 및 LED조명기구에 대한 광학설계를 소개했다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.9
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• pp.3446-3450
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• 2010

This study aims to make class lighting that gives classroom to stability and activity. For the purpose, we develop a emotional lighting LED using LED source which is a environment-friendly and the lighting fo the next generation. We composed emotional lighting LED as controller for color conversion, power supply for supplying LED lamp a stable power, PCB board for LED lamp and lamp and case. We developed designed emotional lighting LED and proved that the system works and one can get intended color.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2014.06a
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• pp.157-159
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• 2014

현재 국내 등명기는 대부분 국내 관련업체의 연구개발에 의하여 국산화 하고 있으나 LED 광원을 적용하는 기술 수분에는 해양선진국에 크게 미치지 못하는 상황이다. 특히 대형등명기에 LED 광원을 적용하는 경우 고출력 LED를 적용한 고용량 LED 광원을 사용하여 광량을 확보하여야 하며 이를 구동하기 위한 LED 드라이버모듈 개발이 필요하다. 또한 고용량 LED광원의 안정적인 구동을 위하여 고용량 LED 모듈의 모니터링 및 제어기술이 동반되어 개발되어야 한다. 이에 고출력 LED 모듈을 안정적으로 구동할 수 있는 LED 드라이버를 설계하고 LED 드라이버를 모듈화하여 안정적인 전원공급과 효율적인 제어가 가능한 LED 대형등명기용 LED 드라이버 모듈을 개발하고자 한다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.10a
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• pp.440-443
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• 2011

This paper aims to compose a new LED lighting control board in the LED lighting environment This LED lighting control board is designed to adjust the brightness of LED lighting depending on the change of surrounding brightness, and it is also designed to control the brightness by using ATmega128, which is an 8bit micro-controller, The PWM wave form likely to output into the LED driver is determined by the ADC value input through ADC.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.05a
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• pp.279-279
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• 2004

1.개요 반도체 기술의 발전으로 에너지 효율이 높고 반영구적인 LED의 개발과 사용이 늘어나고 있는 추세이며, LED 관련 시장도 확대되고 있다. LED 생산에 따른 LED검사 시스템이 필수적인데도 아직 생산 현장에서는 목시검사에 의존하고 있으며, 시스템의 개발은 아직 미비한 상태이다. 몇몇의 비젼 검사관련 업체에서 비젼시스템을 이용한 LED 검사 시스템을 개발하였고, 그 밖에 논문에서 LED 검사 시스템을 개발하고 연구한 바가 있으나, 기존의 LED검사 시스뎀은 전원을 넣어 실제 LED발광 이미지에 대한 검사를 하는 것이 아니라 꺼진 상태에서의 LED 형상에 대한 검사 시스템이다.(중략)

• The Transactions of the Korean Institute of Power Electronics
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• v.19 no.6
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• pp.564-571
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• 2014

A single-stage current-balancing multi-channel light-emitting diode (LED) driver is proposed in this study. The conventional LED driver system consists of two cascaded power conversion stages, i.e., an isolation DC/DC converter and LED driver. LED driver is usually implemented with the same number of expensive boost converters as those of LED channels to tightly control the current through each LED channel. Therefore, its overall system size is not only bulky, but the cost is rather high. By contrast, the proposed LED driver system is composed of a single power stage with the DC/DC converter and LED driver merged. Although the current balancing circuit of the proposed LED driver requires only passive devices instead of expensive boost converters, all currents through multi-channel LEDs can be well balanced. Therefore, the proposed LED driver features a small system size, improved efficiency, and low cost. To confirm the validity of the proposed driver, its operation and performance are verified on a prototype for a 46" LED TV.

• Journal of the Korean Society of Marine Environment & Safety
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• v.16 no.2
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• pp.235-240
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• 2010

In order to substitute incandescent lamps, a power supply device for 7W class LED lamps which are environmentally friendly and energy saving is designed LED lamps consist of a multitude of chip LED connected in parallel and series. 11ms it is necessary to supply LED lamps with DC voltage and current. However, when LED lamps are in use, they are connected directly to AC 220V. This is why we need to have AC/DC, DC/DC power converters including a control system of voltage and current. For this, a transformerless and simple LED lamp driver is designed 조ich can control the current and output voltage for LED string of LED lamp.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.36 no.3
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• pp.255-260
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• 2023

In order to spread LED lighting, LED lighting technology directly driven by alternating current (AC) commercial power has recently been introduced. Since current does not flow at a voltage lower than the threshold voltage of the LED, a non-conductive section occurs in the current waveform, and the higher the threshold voltage of the LED, the more discontinuous current waveforms are generated. In this paper, multi-LED modules are connected in series so that the threshold voltage can be adjusted according to the number of LED modules. A small number of LED modules are driven at a low instantaneous rectified voltage, and a large number of LED modules are driven at a high instantaneous rectified voltage to lengthen the overall lighting time of AC-LED lighting, thereby minimizing the luminance deviation of AC-LED lighting. In addition, the load current flowing through the LED module is adjusted to be the same as the design current even at the maximum rectified voltage higher than the design voltage, so that the light brightness of the LED module is kept constant. Therefore, even if the rectified voltage applied to the LED module changes, the AC-LED lighting in which the light brightness is constant and the luminance deviation is minimal has been realized.

• Journal of the Institute of Electronics and Information Engineers
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• v.49 no.11
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• pp.193-198
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• 2012

An LED converter used to operate an LED with high efficiency and long lifespan, activates an LED by keeping voltage and current constant. In spite of voltage drop by LED's overheating and over-voltage by damage of a power line and by circuit problem, most existing LED converters supply unchanged constant voltage and current to the LED. Eventually, LED is out of order because of over-voltage or over-current. To avoid the breakdown of an LED by over-voltage and over-current, we propose a new scheme which deactivate the PWM circuit in the event of over-current generating. The PWM circuit operates below the pre-determined level of current. While the over-voltage is generated in PWM circuit, the feedback circuit makes the PWM circuit stopped and therefore prevents LED from being damaged by over-voltage and over-current.

• Journal of the Semiconductor & Display Technology
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• v.22 no.2
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• pp.1-5
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• 2023

In the past, display devices have undergone many changes, such as plasma TVs and LCDs, and have continued to develop. Recently, new display technologies, such as Organic Light Emitting Diode displays and Inorganic Light Emitting Diode displays, have been developed. Among them, Micro LED displays have the potential to improve performance more than LCDs and OLEDs, but a lot of effort and time are needed until the mass production technology (transfer and bonding) of Micro LED displays is developed. We have developed a new Micro LED display light source that can be produced using existing transfer and bonding process technologies to enable faster commercialization of Micro LED in the industry. This light source is TFT deposition on LED. TFT deposition on LED has the advantage of being able to produce displays using existing process technology, making early commercialization of display application products possible. In this study, we applied the Active Driving method to verify the performance of TFT deposition on LED as a display to determine its commercialization potential. Additionally, to facilitate faster application of Micro LED in the industry, we applied TFT deposition on LED to Optical Wireless Communication systems, which are widely used in application service areas such as safety/security and sensors, to verify its communication performance. The experimental results confirmed that TFT deposition on LED is not only capable of AM driving but can also be applied to OWC systems.