• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.8
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• pp.128-135
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• 2013

This paper presents a high dimming ratio Power-LED driver IC with high power which is capable of controlling LEDs. In order to accomplish a high dimming ratio LED driver, the preloading inductor current methodology is proposed for the power stage of the proposed method to achieve the fast transient response time during the Power-LED load switching. The information containing the current flowing on the LEDs can be utilized to predict the amount of the current on the inductor. The minimum LED current rising time of existing high dimming ratio Power-LED driver is limited by $3{\mu}s$, however that of the proposed high dimming ratio Power-LED driver is reduced about 1/10. The LED driver is implemented with 0.35um 60V BCDMOS 2-poly 4-metal process. The measurement results show that the proposed LED driver system features the minimum rising time as small as 240ns at the dimming frequency of 1KHz with a 12V of input voltage, nine white LEDs and 353mA of LED current. The LED rising time and power conversion efficiency of the chip are measured to be 240ns and 93.72%, respectively.

• Journal of Satellite, Information and Communications
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• v.9 no.3
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• pp.74-79
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• 2014

Illumination is an effective technique that must be in the mankind today. These lights, there is artificial light that is created by using an artificial light source daylight illumination by sunlight, in this paper, it is created using the electrical energy it is a paper on the study of technology management scheme and efficient control technology of artificial light.

• The Journal of the Korea institute of electronic communication sciences
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• v.10 no.1
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• pp.111-116
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• 2015

In this study, the constant current converter for LED lighting was designed and the electrical characteristics of the fabricated SMPS was measured. When the output current is 300mA the maximum efficiency of 85% was shown and the output current is in the range of 100~400mA efficiency over 70% were exhibited. Also the dimming levels control over the range of 0 to 100% was possible by using a control signal of 0~250mV.

• Proceedings of the KAIS Fall Conference
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• 2009.05a
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• pp.649-652
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• 2009

본 논문에서는 LCD TV의 전력 소비를 절감하기 위해 백라이트 유닛을 다분할하여 디밍 제어를 수행하는 알고리즘을 제안한다. 최근 LED 백라이트 유닛을 채용한 대형 LCD TV가 출시됨에 따라서, 백라이트 유닛의 디밍 제어를 통해 LCD TV에서 전체 전력 소비를 절감하고자 하는 기술이 활발히 연구되어 왔다. 기존의 방식은 전체 화면을 MxN개의 분할로 나누어, 각 분할 영역마다 화면의 최대 밝기 정보를 추출하여 디밍 제어를 수행했지만, 본 논문에서는 각 분할영역마다 인접한 영역으로부터 간섭받는 빛의 양을 반영하여, 실제 디밍 제어 값을 다시 계산함으로써, 추가적인 전력 절감 효과를 얻을 수 있는 방식을 제안하고 성능 평가를 하였다.

• Annual Conference of KIPS
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• 2016.10a
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• pp.843-844
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• 2016

시장으로부터 요구는 야간에도 고화질 영상을 획득하기 위한 기술개발이 필요하다. 우리는 방범용 야간 고화질 영상 확보를 위한 시스템과 감성적인 실내외 조명 관리 시스템을 위한 IADP(IoT Auto Dimming Platform)를 설계한다. 공원이나 학교 등 외부 환경에 따른 LED 오토 디밍 제어 및 접근감지에 따른 밝기 제어, 가정에서 거실등, 침실등, 공부방 등의 환경을 고려한 밝기 제어를 통한 시력 보호 및 감정 제어, 및 테마 프로그램에 의한 주기적 LED 경관 제어를 제공하도록 외부환경에 따른 테마형 IoT 오토디밍 플랫폼 IADP를 설계한다.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.139-140
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• 2015

LED 조명은 고효율화와 고출력화에 따라 실내조명, 경관조명, 가로등조명 등 생활조명산업에서 급속히 적용되고 있으며, 초박형 소형 경량화, 장수명, 수십 마이크로 초 단위의 고속응답 속도, 광색의 시인성 및 재현성 등이 우수하여 IT, BT, NT기술과 융합되어 의료, 농업, 환경, 디스플레이, 정보가전 등의 넓은 응용 분야로 확대되고 있어, LED 디밍제어 기술을 적용하여 다양한 분야에서의 활용에 필요한 성능요건을 만족시킬 수 있다. 본 논문에서는 LED 조명의 밝기조절을 위한 제어방식을 Buck 컨버터를 활용한 정전류 구동방식을 적용하여 제어회로를 보다 단순화하고, 전용 IC를 활용하여 회로구성 방식에 대하여 제안한다.

• 전기의세계
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• v.63 no.7
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• pp.22-26
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• 2014

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.10a
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• pp.188-191
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• 2013

In this paper, in order to economize energy inside the vertical-type water treatment plant, a chamber-illumination-LED control board, which operates via nature light or human's touches, is proposed. Moreover, this illumination control process is contrived to be wirelessly monitored in real-rime. In addition, Zigbee communication code is programmed to implement the control board's function of wireless data transmission and automatic LED brightness control. The presented control method contrives brightness to be adjusted in real-time by dimming control, which means nature light changes control, so that the interior energy can realize the maximum energy conservation.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.7
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• pp.89-95
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• 2014

An LED lighting which adjusted brightness according to the surround ambient implemented using PWM technology and power devices. To measure the brightness of surround ambient a CdS sensor was used. A control board for the generation of the PWM signal was made using a MCU and duty ratio was controlled according to light intensity of surround ambient of the system. To drive the LED lamps which require high-voltage and high-current power devices were used for switching the DC power supply. Measurement results show that the IGBT is excellent as only lineality but the PowerBJT is more good to consider to efficiency and cost.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.4
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• pp.63-69
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• 2014

Visible light communication is a communication method using an LED's blinking(ON/OFF), it has a feature of light because of the limit of perception by the human's optic nerve. LED' dimming control used in the VLC system is important factor needed to provide energy saving and life benefits. With advances in VLC system, MIMO technology has received much attention in that it can be obtain channel capacity proportionate to the number of antenna. Therefore, in this paper, with RC method which is one of the MIMO style in VLC system, it is compared communication performance using RZ-OOK, VPPM, MPPM and OPPM. As a result of the simulation was run against this, MPPM works well in terms of Power requirement and OPPM works well in terms of Spectral efficiency and Bandwidth requirement, also it was confirmed that there is a significant impact on the communication performance of each modulation scheme according to the dimming.