• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.10
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• pp.135-141
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• 2013

In this paper, we installed three high brightness red, green, and blue LED in one socket and made one pixel unit. And we also developed the full-color display board module and control unit which can express various images such as text, graphics, video image with the combination of pixel units and a number of modules. LED display driver module have a driver circuit within the combination of the RGB pixel dot on unit area. These modules of the existing form can be high priced because of implementation a fixed resolution in specific space and installation space. To overcome these shortcomings, we developed a LED driver and LED pixel modules free in array at random pitch intervals. Display board module of this paper enabled to display smoothly video image which have many data processing quantity through dragging data speed up 36 frames per second. Also there are an effect which is provided more clear image because of improving the flickering of the existing display board.

• Proceedings of the KIPE Conference
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• 2004.07b
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• pp.851-854
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• 2004

This paper studies Optical Fiber(OF) - LED illuminated display board system for energy saving. The OF-LED illuminated display board system has PV modules, batteries, and charge & discharge system, and dynamic full color display controller. Both maximum power point tracker (MPPT) and constant current & constant current controls (CCVC) are used In govern the charging system. It can be improve the charging efficiency of battery. The objective of this thesis paper is to build advertisement lighting system with OF-LED in to charge a 12-volts lead acid battery by using a field wired PV array. We saved the maintenance cost and developed of advertisement effectiveness. To verify the proposed OF-LED illuminated display board system for energy saving, the detail simulation and experiment results indicate that operating characteristics are verified by experiment with a laboratory prototype in this paper.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.769-772
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• 2008

For several years, many researchers have proposed LED backlight dimming technology for low power consumption and high contrast ratio. One of the major issues plaguing RGB LED with 2D dimming technology is color shift. This undesirable variation makes it difficult to use RGB LED as light sources in the backlight system. This paper describes the useful method of the optical feedback system for 2D dimming RGB LED backlight. The test results show that our proposed method is very suitable for the 2D dimming technology.

• Journal of the Semiconductor & Display Technology
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• v.17 no.2
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• pp.41-46
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• 2018

This paper proposes a new method for the number recognition on dot matrix LED display. The proposed method uses morphological processing that dilates dots of numbers and connects the dots into strokes. The size of numbers is normalized using horizontal projection because the gaps of dots are different according to the size of numbers. The numbers are segmented by connected component analysis and finally, template matching method recognizes the segmented numbers. The proposed method is implemented using C language in Raspberry Pi system with a camera module for a real-time image processing. Experiments were conducted by using various dot matrix LED displays. The results show that the proposed method is successful for the number recognition on dot matrix LED display.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.229-230
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• 2009

This paper proposes a new design of ultra-slim color mixing lens (CML) for backlight unit (BLU), and presents simulated performance of the design. The novel color mixing structure has a shorter mixing length (< 1cm) than the existing color mixing structure, and achieves high efficiency and uniformity.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.143-146
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• 2008

Dynamic range of LCD panel can be dramatically improved by adaptive dimming technique. Adaptive control of LED backlight by input signal can reduce the light leakage of LCD panel and achieve high contrast ratio. An algorithm is proposed to distinguish the input signal and get proper luminance level. For lower cost of LCD panel, white light LED is used to accomplish 2D dimming and get better image performance of LCD.

• The Journal of the Korea institute of electronic communication sciences
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• v.10 no.5
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• pp.587-592
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• 2015

According to increase in the use of the LED, the demand for low power consumption LED display design of the controller block has increased. In this paper, the low power LED controller block was designed through the power source supply that leads adiabatic operation from constant current source circuit operated by digital signal control. The proposed circuit was implemented using a 0.35um CMOS process. and it demonstrated linear operation of the circuit. From the simulation result, the proposed circuit was evaluated with about 82% power consumption reduction effect in comparison with conventional LED controller block. This research is expected to be helpful for the low power operation and the solution for heat problem of LED display.

• 전자공학회논문지 IE
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• v.46 no.3
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• pp.12-18
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• 2009

In this paper, we developed white balance correction processor for Full Color LED Display System which could be display uniformity color and soft light by adjusting brightness of red, green, blue pixel, individually. This processor correct brightness by calculating operating current of each pixel(red, green, blue LED) on the basis of characteristic curve of LED device when we named "a" as a specific characteristic value, "b" as a brightness correction value according to using time, "X" as a operating current value, and "Y" as brightness value. As the results, we solved the reduction problem of brightness for long used LED devices, according to increase entire mean of brightness value by adjusting "b" value from the brightness characteristic function.

• Journal of Broadcast Engineering
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• v.21 no.5
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• pp.816-823
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• 2016

This paper studies a light emitting diode(LED) overlapping method of a head-up display that consists of a digital micro device(DMD) panel and a red, green, blue LED in order to increase the brightness of display system and optical output power. This optimization overlapping method removes a quantization noise which occur due to LED overlapping too excessive and stabilizes the junction temperature of LED. In order to reduce junction temperature of LED, the a correlation between a green duty and LED overlapping ratio is studied. Throughout this study, the brightness of head-up display exhibited high increasement ratio of luminance around 33.3 percent at 39 percent overlapping method.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.2-6
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• 2009

This presentation reviews the current progress in the technology of Light Emitting Diode (LED) as it relates to the LED backlight for Liquid Crystal Display (LCD). A vivid description is given about the performance of LED that is still on the rise and certain limitations of LED that is on the decline.