• Title/Summary/Keyword: Blinking driving

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Characteristics of Motion-blur Free TFT-LCD using Short Persistent CCFL in Blinking Backlight Driving

  • Han, Jeong-Min;Ok, Chul-Ho;Hwang, Jeoung-Yeon;Seo, Dae-Shik
    • Transactions on Electrical and Electronic Materials
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    • v.8 no.4
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    • pp.166-169
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    • 2007
  • In applying LCD to TV application, one of the most significant factors to be improved is image sticking on the moving picture. LCD is different from CRT in the sense that it's continuous passive device, which holds images in entire frame period, while impulse type device generate image in very short time. To reduce image sticking problem related to hold type display mode, we made an experiment to drive TN-LCD like CRT. We made articulate images by turn on-off backlight, and we realized the ratio of Back Light on-off time by counting between on time and off time for video signal input during 1 frame (16.7 ms). Conventional CCFL (cold cathode fluorescent lamp) cannot follow fast on-off speed, so we evaluated new fluorescent substances of light source to improve residual light characteristic of CCFL. We realized articulate image generation similar to CRT by CCFL blinking drive and TN-LCD overdriving. As a result, reduced image sticking phenomenon was validated by naked eye and response time measurement.

Intelligent Drowsiness Drive Warning System (지능형 졸음 운전 경고 시스템)

  • Joo, Young-Hoon;Kim, Jin-Kyu;Ra, In-Ho
    • Journal of the Korean Institute of Intelligent Systems
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    • v.18 no.2
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    • pp.223-229
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    • 2008
  • In this paper. we propose the real-time vision system which judges drowsiness driving based on levels of drivers' fatigue. The proposed system is to prevent traffic accidents by warning the drowsiness and carelessness using face-image analysis and fuzzy logic algorithm. We find the face position and eye areas by using fuzzy skin filter and virtual face model in order to develop the real-time face detection algorithm, and we measure the eye blinking frequency and eye closure duration by using their informations. And then we propose the method for estimating the levels of drivel's fatigue based on measured data by using the fuzzy logic and for deciding whether drowsiness driving is or not. Finally, we show the effectiveness and feasibility of the proposed method through some experiments.

Recent Development of Optically Compensated Bend (OCB) Mode TFT-LCD

  • Wakemoto, Hirofumi;Nishiyama, Kazuhiro;Nakao, Kenji;Takimoto, Akio
    • 한국정보디스플레이학회:학술대회논문집
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    • 2005.07a
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    • pp.562-566
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    • 2005
  • Toshiba Matsushita Display Technology (TMD) has firstly succeeded in mass production of OCB (Optically Compensated Bend) mode liquid crystal display panels which have excellent moving picture quality almost the same as CRT. We have newly developed 32 -inch diagonal HD ($1366{\times}768\;pixels$) panels using OCB mode and low temperature p-Si TFT (LTPS) array substrates. High performance of brightness of $600cd/m^2$ and contrast ratio of 600 : 1 was obtained by using pseudo-impulse driving method to insert a black period between continuous two frames, and also by using blinking backlight method. Furthermore, moving picture response time (MPRT) 6.5ms has been obtained by optimization of black insert driving and backlight blinking, without the great sacrifices of contrast ratio and luminance.

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Model on the Contact Lens Movement from Eye-lid Blinking (순목 작용에 의한 콘택트 렌즈의 운동 모델)

  • Kim, Daesoo
    • Journal of Korean Ophthalmic Optics Society
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    • v.9 no.1
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    • pp.145-159
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    • 2004
  • A mathematical model and its computer solution program were proposed to analyze the motion of contact lenses which are being subject to lid-blinking. The equation was derived by incorporating an acceleration induced lid's force exerting on the contact lens, the viscous damping resistance in the tear layer beneath the lens and the sliding frictional force between the lid and the contact lens surface into the formulation of differential equation describing the vibration. The model predicts the time-dependent displacement from the equilibrium postion during/after the blinking. During the blinking, as the time for the completion of one cycle of blinking decreases the off-the-equilibrium displacement of contact lens increases while the decrease of diameter in the contact cause the opposite effect. It is found that lid pressure exerting on the lens cause an insignificant lens displacement from the equilibrium position. After blinking the frequency of damped oscillation of contact lens decreases as the diameter of lens increases, due to the incresed surface while the reduced blinking time does not cause a significant frequency change. This is because that driving force for the contact lens movement posterior to blinking is the capillary-induced force not the lid force.

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Drowsiness-drive Perception System Using Vision (비젼을 이용한 졸음운전 감지 시스템)

  • Joo, Young-Hoon;Kim, Jin-Kyu
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.57 no.12
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    • pp.2281-2284
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    • 2008
  • The purpose of this paper is to develope the drowsiness-drive perception system which judges drowsiness driving based on drivers' eye region using single vision system. To do this, first, we use the Haar-like feature and AdaBoost learning algorithm for detecting the features of the face region. And we measure the eye blinking frequency and eye closure duration from these feature data. And then, we propose the drowsiness-drive detection algorithm using the eye blinking frequency and eye closure duration. Finally, we have shown the effectiveness and feasibility of the proposed method through some experiments.

Driver's Eye Blinking Detection Method based on Template Matching using Line Profile (라인 프로파일을 이용한 템플릿 매칭 기반의 운전자 눈 깜박임 검출 방법)

  • Kim, Young Jae;Shin, Seung Seob;Kim, Kwang Gi
    • Journal of Korea Multimedia Society
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    • v.20 no.6
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    • pp.873-881
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    • 2017
  • Prevention of drowsy driving is one of the important issues for safe driving. In this study, the algorithm for detection of drowsy driving has been developed. The algorithm was implemented by applying template matching and line profile, which detects eye blink. The accuracy of eye detection and blink detection was $97.45{\pm}3.67%$ and $98.50{\pm}0.92%$, which was resulted from the verification experiment that 21 subjects participated. Consequently, the algorithm is expected to be used to prevent sleep-deprived driving.

Implementation of A Safe Driving Assistance System and Doze Detection (졸음 인식과 안전운전 보조시스템 구현)

  • Song, Hyok;Choi, Jin-Mo;Lee, Chul-Dong;Choi, Byeong-Ho;Yoo, Ji-Sang
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.49 no.3
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    • pp.30-39
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    • 2012
  • In this paper, a safe driving assistance system is proposed by detecting the status of driver's doze based on face and eye detection. By the level of the fatigue, safe driving system alarms or set the seatbelt on vibration. To reduce the effect of backward light and too strong solar light which cause a decrease of face and eye detection rate and false fatigue detection, post processing techniques like image equalization are used. Haar transform and PCA are used for face detection. By using the statistic of the face and eye structural ratio of normal Koreans, we can reduce the eye candidate area in the face, which results in reduction of the computational load. We also propose a new eye status detection algorithm based on Hough transform and eye width-height ratio, which are used to detect eye's blinking status which decides doze level by measuring the blinking period. The system alarms and operates seatbelt on vibration through controller area network(CAN) when the driver's doze level is detected. In this paper, four algorithms are implemented and proposed algorithm is made based on the probability model and we achieves 84.88% of correct detection rate through indoor and in-car environment experiments. And also we achieves 69.81% of detection rate which is better result than that of other algorithms using IR camera.

Study of Blurring Free TFT-LCD Using Short Persistance Cold Cathode Fluorescent Lamp in Blinking Backlight Driving (단잔광 냉음극관을 이용한 잔상없는 TFT-LCD에 관한 연구)

  • Choi, Dae-Seub;Sin, Ho-Chul
    • Journal of Satellite, Information and Communications
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    • v.7 no.3
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    • pp.145-148
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    • 2012
  • In applying LCD to TV application, one of the most significant factors to be improved is image sticking on the moving picture. LCD is different from CRT in the sense that it's continuous passive device, which holds images in entire frame period, while impulse type device generate image in very short time. To reduce image sticking problem related to hold typedisplay mode, we made an experiment to drive TN-LCD like CRT. We made articulate images by turn on-off backlight, and we realized the ratio of Back Light on-off time by counting between on time and off time for video signal input during 1 frame (16.7ms). Conventional CCFL (cold cathode fluorescent lamp) cannot follow fast on-off speed, so we evaluated new fluorescent substances of light source to improve residual light characteristic of CCFL. We realized articulate image generation similar to CRT by CCFL blinking drive and TN-LCD overdriving. As a result, reduced image sticking phenomenon was validated by naked eye and response time measurement.

Operation Pattern Control of High-brightness LED Warning Light (고휘도 LED경광등 동작 패턴 제어)

  • Lim, Sung-Moo;Shin, Kyung-HO;Song, Sang-Bin;Yeo, In-Seon
    • Proceedings of the KIEE Conference
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    • 2004.11a
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    • pp.261-263
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    • 2004
  • This paper studies the lighting pattern control of a high-brightness LED warning light. The driving circuit for the warning light is composed of a full-wave rectified circuit and of a control circuit using a micro-controller (AT89c2051). The micro-controller is programmed in a suitable manner to accomodate a number of variable lighting patterns and to adjust the blinking speed. To reduce the total number of LEDs installed a special consideration is made to the bundled pattern in a lamp module which is lit simultaneously. The resultant LED warning light has merits not only over the conventional incandescent warning light on the energy saving aspect but also over some other LED-type ones in the market.

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Vision based Traffic Light Detection and Recognition Methods for Daytime LED Traffic Light (비전 기반 주간 LED 교통 신호등 인식 및 신호등 패턴 판단에 관한 연구)

  • Kim, Hyun-Koo;Park, Ju H.;Jung, Ho-Youl
    • IEMEK Journal of Embedded Systems and Applications
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    • v.9 no.3
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    • pp.145-150
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    • 2014
  • This paper presents an effective vision based method for LED traffic light detection at the daytime. First, the proposed method calculates horizontal coordinates to set region of interest (ROI) on input sequence images. Second, the proposed uses color segmentation method to extract region of green and red traffic light. Next, to classify traffic light and another noise, shape filter and haar-like feature value are used. Finally, temporal delay filter with weight is applied to remove blinking effect of LED traffic light, and state and weight of traffic light detection are used to classify types of traffic light. For simulations, the proposed method is implemented through Intel Core CPU with 2.80 GHz and 4 GB RAM, and tested on the urban and rural road video. Average detection rate of traffic light is 94.50 % and average recognition rate of traffic type is 90.24 %. Average computing time of the proposed method is 11 ms.