• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.1118-1120
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• 2003

For LCD-TVs with full capability to show moving pictures and LCD monitors for multi media use, it is necessary that the switching times of Liquid Crystal (LC) mixtures are within one frame (16.7ms). In order to achieve faster switching times, new LC materials have been identified, mainly focusing on the further reduction of the rotational viscosity (${\gamma}1$).

• Journal of the Korean Institute of Telematics and Electronics
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• v.25 no.1
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• pp.88-93
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• 1988

For coherent optical information processing the thickness uniformity of the spatial light modulators(SLMs)is highly demanded. The liquid crystal display(LCD), which is commercialized as a pocket-sized television, is considered as one of the most cheap 2-dimensional SLM. But usually it has lack of thickness uniformity. Thus phase correction to compensate the thickness nonuniformity must be preceded before it is used as an SLM. In this paper relatively easy phase compensation method applicable to binary SLMs is discussed and experimentally verified by using the optical joint transformantion concept.

• Proceedings of the KIPE Conference
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• 2006.06a
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• pp.387-389
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• 2006

The LCD TV has many variable functions for consumer. Low temperature driving below minus 20 degree is also one of key functions. Since LCD is not self-luminance device, it is needed backlight system. Recently EEFL(External Electrode Fluorescent Lamp) widely substitutes for CCFL(Cold Cathode Fluorescent Lamp). It is more cheaper, higher efficiency, and easy to drive parallel connection compared to CCFL. In this paper, several conditions for low temperature driving of EEFL are investigated and a new boost-half bridge inverter for low temperature driving is proposed. Mode analysis is described and experimental results is represented to verify validity of the proposed inverter.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.987-990
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• 2009

Motion-induced artifacts on LCDs appear as blurred boundaries and/or color aberration between the moving objects and background. Perceived degree of the motion-induced artifacts depends on the blur width as well as color difference. This paper presents a quantitative measure for the motion-induced artifacts on LCDs. Performance of the proposed measure is verified by calculating correlation coefficients between the proposed measures and the results of human visual tests performed on the 240 Hz and 120 Hz scanning LCD TVs.

• Journal of Information Display
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• v.12 no.2
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• pp.77-83
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• 2011

The memory compression algorithm CCC-LCP (color-count-controlled local color palette) reduces flicker in the liquid crystal display (LCD) overdrive. Its compression ratio is 1:5.4 for 10-bit images, with a 33 dB PSNR peak signal-to-noise ratio and with five times flicker reduction compared with the block truncation coding. The authors' two-alternative forced choice subjective tests proposed two new soundness properties, the 'CMP harmlessness' and 'OD non-lost (or OD liveliness)', to clarify the functional interaction between the overdrive functionality OD and the compression functionality CMP. The tests verified that CCC-LCP is practically applicable (at a 1.2H viewing distance threshold) for 42" 37-ppi WXGA TVs.

• Journal of Power Electronics
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• v.10 no.4
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• pp.351-356
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• 2010

A new current-balancing multi-channel LED driver is proposed in this paper. The conventional LED driver system consists of three cascaded power conversion stages and its driver stage has the same number of expensive boost converters as those of the LED channels. On the other hand, the proposed LED driver system consists of two cascaded power stages and its driver stage requires only passive devices instead of expensive boost converters. Nevertheless, all of the currents through multi-channel LEDs can be well balanced. Therefore, it features a smaller system size, improved efficiency, and lower cost. To confirm the validity of the proposed driver, its operation and performance are verified on a prototype for a 46" LCD TV.

• Journal of Internet Computing and Services
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• v.11 no.1
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• pp.21-26
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• 2010

In this paper, film uniformity is improved by the bolt-mapping of convolutional image processing between bolts and a film using soft X-ray based in-line LCD TV film thickness controls. The automatic film thickness analysis of 3 inter-bolt's convolution function is proposed for the reduction of offset error from the X-ray changing of line scan in film profiles.

• Proceedings of the KIEE Conference
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• 2008.04a
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• pp.211-212
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• 2008

정보가전기기들의 대형화 제품개발 및 생산에 따른 전력소모가 극대화 되어있는 현실에 에너지소비를 줄이기위한 많은 연구들이 진행되고 있다. 그 중 LCD TV 분야는 전체 전력소비의 약 70% 이상이 Back-light에 의해 소비되므로 효율석인 Back-light 설계에 관한 관심이 증가하고 있다. 근래에 전통적인 CCFL 방식의 flack-light 구조에서 LED Back-light으로 점차 대체되어가고 있으며, 이러한 변화는 앞으로도 지속적으로 증가하기라 예상된다. 따라서, LED Hack-light의 효율적인 선력관기는 산업적 측면에서도 매우 주요한 부분이라 할 수 있다. 본 논문은 대형 TV의 에너지효율을 높이기위한 LED Rack-light 구성에 관한 요소들을 관계를 기술하고, 특히 Back-light 밝기제거를 통한 효율적인 전력관리를 실현위한 다채널 구동제어신호 생성에 관해 설명한다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.15-15
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• 2009

In many applications for display with LED, the thermal behavior of LED is most important issue in view of thermal management. The optical requirements of the displays for various applications make the designer to drive the LED at or over their on-design condition to achieve performances requested by users. In practical cases of large-sized TV with LED back light unit (BLU), the problem of increasing LED temperature can affect the reliability of LED itself and the optical performances of BLU as an assembly of LED. In this paper, the thermal management design of LED back light unit(BLU) for large-sized TV was performed

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.1673-1675
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• 2006

As the manufacturing capacity needs for large size LCD TV shifts very fast into next generation, processing and test equipment makers face more difficult challenges in accommodating productivity, reliability and lead time of panel makers as well as the prerequisite of high process quality. In this paper, AKT will discuss its new innovative productivity solutions in PECVD (Plasma Enhanced Chemical Vapor Deposition), as the key thin film process system, and EBT (Electron Beam Test), as the key array test system, for the huge glass size with surface dimension larger than 2 meter by 2 meter.