• Title/Summary/Keyword: LCD TVs

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Is Bigger Better?

  • Barnes, David
    • 한국정보디스플레이학회:학술대회논문집
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    • 2001.08a
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    • pp.13-21
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    • 2001
  • Increased investment costs for larger substrate factories require breakthrough efficiencies and the capture of price premiums. Otherwise, their profit indicators will fall below those of prior plant investments. Market factors inhibit the continued expansion of monitor size and resolution, so a television market must be developed if substrate size increases will remain profitable, long term.

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Smart Dimming Control Algorithm for Reducing Power Consumption of LED TV Backlight (LED TV 백라이트 소비전력 저감을 위한 스마트 디밍 알고리즘 개발)

  • Ryu, Je-Seung;Park, Ju-Hee;Lim, Seong-Ho;Kim, Tae-Woo
    • The Transactions of the Korean Institute of Power Electronics
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    • v.19 no.4
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    • pp.320-326
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    • 2014
  • In this paper, the new smart dimming algorithm which is mixed with PWM and PAM control method is proposed for reducing the power consumption of LED TV Backlight. The proposed technique is using the curve characteristics of LED forward voltage and current which is proportionally changing LED forward voltage as changing LED forward current. Therefore, each PWM and PAM control method has different LED forward voltage and current in the same brightness condition. The PWM control method adjusts the brightness of LED TV Backlight by only varying the duty ratio of PWM and constantly sustaining the amplitude of LED forward current and voltage. So, the level of LED forward current and voltage in the PWM control method is relatively high and constant regardless of duty ratio of PWM. On the other hand, the PAM control method adjusts the brightness of LED TV Backlight by directly varying the level of LED forward current. So, the level of LED forward current and voltage in the PAM control method is lowered according to the brightness level. For the above-mentioned reason, the PAM control method has the advantage of reducing the total power consumption of LED TV Backlight at the brightness condition of below 100%, compared with PWM control method. By implementing this characteristic to LED driver circuit with control algorithm in MCU, the power consumption of LED TV Backlight can expect to be reduced. The effectiveness of the proposed method, new smart dimming algorithm, CPWAM(=Conditional Pulse Width Amplitude Modulation), has been verified by experimental results.

Luminance Properties and Electrical Properties by Applied Frequency of External Electrode Fluorescent Lamp(EEFL) (EEFL의 주파수 변화에 따른 전기적 특성과 휘도특성)

  • Lee, Seong-Jin;Lee, Jong-Chan;Park, Noh-Joon;Park, Dae-Hee
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.56 no.2
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    • pp.355-360
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    • 2007
  • The recent TFT-LCD Trend that is done large size gradually. As size of monitor great, though problem happens, it is that consumer's request which it makes monitor combined TV function. Monitor and TV are no difference externally greatly, but define difference happens as for backlight. An external electrode fluorescent lamp (EEFL) has an advantage of a long lifetime in the early stages of the study on plasma discharge, interest in the lamp continues. Researches on the operation of external electrode fluorescent lamps have focused mainly on its use of a type of high frequency (MHz). By performing high Luminance using a square wave operation method with the low frequency below 100kHz, which is applied to a narrowed tube type lamp that has several mm of lamp diameter, EEFL presented the possibility of using it as a light source for back-lights. However, because EEFL generates plasma using wall charges, which considers the impedance characteristics of glass based on the structural principle in discharge, it can be significantly affected by frequency. Thus, this study verified the change in the characteristics of electromagnetic fields according to the change in frequency through a Maxwell electromagnetic field simulation and examined the relationship between the change in the EEFL frequency and Luminance by measuring the optical characteristics.

Device Independent Remote Controlling Using a 8-bit Microcontroller (마이크로콘트롤러를 사용한 만능 적외선 리모컨 제어)

  • Kim, Jin Young;Moon, Sangook
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2016.05a
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    • pp.412-413
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    • 2016
  • Remote control for consumer electronics products that nowadays are divided by the state only performs each function. In any case, there is also the case that the number of losing too many messes Where remote control. In this paper, the reason and remote control using infrared remote control transmission, will be able to see the modulation method of the received remote control method. The experiment will be able to see that by looking at the LCD to ATmega128 control home appliances (TV, air conditioning, etc.). As a result, it will be able to deal with a single remote control electronics to reduce the number of the remote control to handle all further electronics in the home.

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Design of high speed data processing controller for the full color LED display board system (풀칼라 LED 전광판용 고속 데이터처리 제어장치 설계)

  • 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.2
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    • pp.462-468
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    • 2010
  • In this paper, the new efficient drive control technology based on the conventional full-color electric display board image processing method is proposed. This technology can be applied to high-fidelity large size panel TV and LCD Display, and makes high-fidelity-display-drive control possible in those. The proposed drive control technology can strengthen the image processing function of the conventional technology. Also, the automatic or manual adjustment of contrast, bright, tint, color, gamma revision, etc. can help to achieve high-fidelity vision. This technology can be adopted with lower price.

Zero-Transient Current Control Method for PWM Dimming of LED (LED의 펄스폭 변조를 통한 휘도조절시 과도구간이 존재하지 않는 전류 제어 기법)

  • Yoon, Young-Nam;Lee, Sang-Hyun;Cho, Sang-Ho;Hong, Sung-Soo;Kim, Chang-Sub;Lee, Hyo-Bum;Han, Sang-Kyoo
    • The Transactions of the Korean Institute of Power Electronics
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    • v.16 no.1
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    • pp.64-70
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    • 2011
  • This paper presents a zero-transient current control method for PWM dimming of LED. Since the proposed LED current control method has no transient state, it features a high resolution, high linearity, and no current overshoot through LED along a wide dimming range. The operational principles of the proposed LED current control circuit are presented. To confirm the validity of the proposed method experimental results from a prototype circuit of the 46-inch LCD TV are given.

Application of Optical Simulation in Direct-type Backlight Design (직하형 백라이트 설계의 광학시뮬레이션의 응용)

  • Han, Jeong-Min;Kim, Byoung-Yong;Kang, Dong-Hun;Kim, Young-Hwan;Kim, Jong-Hwan;Lee, Sang-Keuk;Ok, Chul-Ho;Seo, Dae-Shik
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2007.06a
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    • pp.415-415
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    • 2007
  • In this study. it was investigated about optical simulation in direct-type backlight design. Direct-type backlight has been used high-brightness backlight such as LCD television application. The key parameter in designing direct-type backlight was consists of three geometrical dimension such as the distance of two lamps. the gap of lamp and reflection plate and the number of lamps. It has many variation in optical design and it causes the different properties in backlight system. It shows the best values of above parameters; 26mm of the distance of two lamps. 4.5mm of the gap of lamp and reflection plate and 16 lamps. And we produced the specimen as above condition. and acquired good result in backlight such as the value of the brightness is 6436 nit in center of emission area and less than 5% in brightness uniformity. It shows the effective ways of designing backlight system using optical simulation method.

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Comparis on of Optical Characteristics between CCFL and EEFL in Direct-Type Backlight Unit (직하형 백라이트에서의 CCFL과 EEFL의 광학특성 비교)

  • Kim, Byoung-Yong;Kim, Jong-Yeon;Kim, Young-Hwan;Lee, Sang-Keuk;Kim, Jong-Hwan;Han, Jeong-Min;Ok, Chul-Ho;Seo, Dae-Shik
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2007.06a
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    • pp.428-428
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    • 2007
  • In this study, It was studied about the luminance characteristics of 17inch direct-type back light using EEFL(External Electrode Fluorescent Lamp). EEFI has a long life time because the electrode is installed outside of lamp. And it is produced low price than conventional CCFL. It does not need process of installing internal electrode. But EEFL technology has several problems such as difficulty of design driving inverter, and prevents leckage current along the skin of lamps. Therefore, by the optimizing of inverter properties, 7525 nit center luminance was acquired in almost same power consumption condition. It was almost same luminance in CCFL backlight unit. And it was operated stably in low operating temperature such as the value of $40^{\circ}C$, so that it was adopted in conventional LCD-TV application.

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Fast Response Time in IPS Mode Using LC mixtures with High Elastic Constant

  • Lim, C.S.;Lee, J.H.;Choi, H.C.;Oh, C.H.;Yeo, S.D.;Lee, Seung-Eun;Jin, Min-Ok;Kang, Doo-Jin;Klasen-Memmer, M.;Tarumi, K.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2004.08a
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    • pp.843-846
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    • 2004
  • For the fast growing Liquid Crystal Display (LCD) TV market, it is essential to make the LCD panels to show moving images without any visual difficulties such as blurring or tailing. Owing to reduction of the cell gap and the improved Liquid Crystal (LC) mixtures with low viscosity, it is possible that our S-IPS TFT-LCDs feature a response time (R/T) as fast as 1-frame time (16ms) for a white-black operation and less than a 16rns in all gray levels without Over Driving Circuit (ODC) technology. Currently, mass production of the large size IPS panels with high speed has been successfully achieved. In order to achieve faster response time, new LC mixtures have been developed, optimizing the physical properties of rotational viscosity (${\gamma}$1) and elastic constants (Kii). Also, the LC mixtures with high elastic constant allow us to increase the cell gap. In this paper, realization of fast switching time in IPS mode with optimized '${\gamma}$1/Kii' parameter in the LC mixtures forms the core of this paper.

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