• Title/Summary/Keyword: brightness control

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Analysis on LGP with Multi-Side-Lamp (다변 광원 도광판에 대한 연구)

  • Park Jong-Ryul;Sah Jong-Youb
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.29 no.3 s.234
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    • pp.361-368
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    • 2005
  • LGP(Light-Guide Panel) of LCD backlight is one of the major componets which affect on the product quality of LCD. The LGP with multi-side lamp has been analized for pattern design with the uniform distribution of brightness. When given the uniform distribution of brightness as target, the distribution of dot pattern has been designed for superposed distributions of brightness for each lamp. Multi-side lamp has been tested for various types such as ㄴ-, ㄷ-, and ㅁ -shapes. The present study enhances the possibility of LGP with multi-side lamp by showing the pricise control of brightness distribution.

A New Method of Brightness/Contrast Control in color displays for user convenience (사용자 편의성을 높인 영상 디스플레이의 Brightness/Contrast 조절 방법)

  • 김홍석;박승옥;백정기
    • Proceedings of the Korean Society for Emotion and Sensibility Conference
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    • 1998.11a
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    • pp.70-73
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    • 1998
  • 영상 디스플레이에서 Brigtness와 Contrast의 조전상태는 영상색에 지대한 영향을 미친다. 본 연구에서는 최적의 Contrst와 Contrast 상태를 손쉽게 조절할 수 있는 패턴을 고안하였으며 Brightness/Contrast 통합 조절방법을 제시하여 주변 조명이나 개인의 감성에 따른 영상색의 쉽고 다양한 조정을 가능하게 하여 사용자의 편의성을 높였다.

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Recognition of License Plate with Brightness and Tone of Color Data (명암과 색상 정보를 이용한 번호판 인식)

  • Lee, Seung-Su;Lee, Kee-Seong
    • Proceedings of the KIEE Conference
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    • 2003.11c
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    • pp.528-531
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    • 2003
  • Recognition of licence plate becomes a key issue to many traffic related application such as road traffic monitoring or parking lots access control. In this paper, the brightness, YIQ and HSI methods were used to locate a license. After the characters in license plate were extracted, template matching method was applied for character recognitions. To test the performance of the proposed algorithm, images of seventy vehicle were tested. The success rates for license plate and character recognition were approximately 99%, and 96%, respectively

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Low Power Consumption Technology for Mobile Display

  • Lee, Joo-Hyung
    • 한국정보디스플레이학회:학술대회논문집
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    • 2009.10a
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    • pp.402-403
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    • 2009
  • A variety of power reduction technologies is introduced and the benefits of the technologies are discussed. PenTile$^{(R)}$ DBLC (Dynamic Brightness LED Control) combined with SABC (Sensor-Based Adaptive Brightness Control) enables to achieve the average LED power consumption to one third. The panel power reduction of 25% can be achieved with low power driving technology, ALS (Active Level Shifter). MIP (Memory In Pixel) is expected to be useful in transflective display because the whole display area can be utilized in reflective mode with power consumption of 1mW.

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Using High Brightness LED Light Source Controller for Machine Vision (고휘도 LED를 이용한 머신비전용 조명광원 제어기 개발)

  • Park, Yang-Jae
    • Journal of Digital Convergence
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    • v.12 no.4
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    • pp.311-318
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    • 2014
  • This paper is to introduce a lighting source controller using high brightness LED to create a clear and reliable condition for an accurate measurement and testing, which is a core technology in clinical image system and mechanical automation system. This controller is designed to supply a stable power in a constant-current system by installing a high brightness LED driver, and to improve the reproducibility of brightness by using 32-bit ARM processor core, dividing brightness quantity into 256 levels, making the remote control and the external interface possible, and preventing and digitizing the brightness inaccuracy caused by errors of resistance values. This controller enables the lighting range to be wide and possible in a low lighting level compared to analog, adds the RS-485 communication function, and makes it for the users to control the on-off function and the dimming level by receiving date from an external device.

Development of the Full color LED displays using the control algorithm of histogram distribution (히스토그램 분포 제어가 가능한 풀칼라 LED 디스플레이장치 개발)

  • Ha, Young-Jae;Jin, Byung-Yun;Kim, Sun-Hyung
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.14 no.7
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    • pp.1708-1714
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    • 2010
  • In this paper, the full color LED billboard or a general quality improvement methods of quality gamma correction, brightness, and brightness adjustment, etc., regardless of the overall color of images uniformly bright or dark have been taken care of. The video itself, but simply expressed as a uniform brightness of a certain size, how to adjust the brightness of input video signal does not reflect the characteristics of the entire screen with just a lighter or darker line is only feeling was brought. So, unlike conventional video transmission system with new LED display technology in the histogram analysis of image data is input by the input image data by determining the luminance values of the attributes are reflected, as appropriate based on the histogram of the distribution of brightness values By controlling the LED display is expressed in the uniform image can improve the brightness control, histogram distribution of the image as full color billboards driven processing technology is proposed.

An Image Contrast Enhancement Method Using Brightness Preserving on the Linear Approximation CDF

  • Cho, Hwa-Hyun;Choi, Myung-Ryul
    • 한국정보디스플레이학회:학술대회논문집
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    • 2004.08a
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    • pp.243-246
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    • 2004
  • In this paper, we have proposed the contrast control method using brightness preserving on the FPD(Flat Panel Display). The proposed algorithms consist of three blocks: the contrast enhancement, the white-level-expander, and the black-level-expander. The proposed method has employed probability density function in order to control the brightness of the image changed extremely. In order for real-time processing, we have calculated cumulative density function using the linear approximation method. The image histogram and image quality were compared with the conventional image enhancement algorithms. The proposed methods have been used in display devices that need image enhancement such as LCD TV, PDP, and FPD.

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User's characteristics on the screen adjustment of color TV (칼라 TV의 화면조정에 관한 사용자 특성)

  • Jeong, Gwang-Tae;Park, Jae-Hui;Yu, Geum-Seon
    • Journal of the Ergonomics Society of Korea
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    • v.18 no.2
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    • pp.81-89
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    • 1999
  • User's characteristics on the screen adjustment of color TV were studied. Two experiments were performed. In the first experiment, the characteristic of screen adjustment according to TV program, ambient luminance, and gender was investigated. Twenty subjects (10 females and 10 males) were participated in this experiment. Set points of brightness, contrast, tint, and color were measured on TV screen and analyzed. Brightness and contrast were significant on gender at significant level 0.01 and color was significant on gender at significant level 0.1. Tint was significant on program at significant level 0.01. The second experiment was performed to supplement the first experiment. The influences of ambient luminance, presented image, screen setting criteria, and gender were investigated. We simplified the first experiment in the second one. We restricted dependent variables (screen control variables) to only two, brightness and contrast. Other control variables were fixed to middle values. Brightness and contrast were significant on gender and screen setting criteria at significant level 0.01. In conclusion, we found that ambient luminance and presented image had no significant effects on TV screen adjustment and TV program had only a significant effect on tint. However, we found that gender and screen setting criteria had significant effects in most conditions.

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A Study on Edge Detection using Pixel Brightness Transfer Function in Low Light Level Environments (저조도 환경에서 화소의 휘도 변환 함수를 이용한 에지 검출에 관한 연구)

  • Lee, Chang-Young;Kim, Nam-Ho
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.19 no.7
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    • pp.1680-1686
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    • 2015
  • Edge detection is an essential preprocessing for most image processing application, and there are several existing detection methods such as Sobel, Roberts, Laplacian, LoG(Laplacian of Gaussian) operators, etc. Those existing edge detection methods have not given satisfactory results since they do not offer enough pixel brightness change in low light level environment. Therefore, in this study new algorithms using brightness transfer function in the preprocessing and for edge detection applying standard deviation and average-weighted local masks are proposed. In addition, the performance of proposed algorithms was evaluated in comparison with the existing edge detection methods such as Sobel, Roberts, Prewitt, Laplacian, LoG operators.

4-channel Light Medical Therapy Apparatus for External Injury Cure (체외 상처 치유를 위한 4-채널 광 치료기)

  • Cheon, Min-Woo;Kim, Seong-Hwan;So, Keum-Young;Moon, Young-Lae;Mun, Seong-Pyo;Park, Yong-Pil;Lee, Ho-Sik;Kim, Tae-Gon
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.20 no.8
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    • pp.731-735
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    • 2007
  • We developed the 4channel Light Medical Therapy Apparatus for External Injury Cure using a high brightness LED. This equipment was fabricated using a micro-controller and a high brightness LED, and designed to enable us to control light irradiation time, intensity, frequency and so on, Especially, to control the light irradiation frequency, FPGA was used, and to control the change of output value, TLC5941 was used. Control stage is divided into 4 levels by program. Consequently, the current value could be controlled by the change of level in Continue Wave(CW) and the output of a high brightness LED could be controlled stage by stage. Compared with one LED irradiation, several LEDs irradiation could increase optical power.