• Current Optics and Photonics
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• 제1권5호
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• pp.474-490
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• 2017

Since the recent slowdown in the smartphone market, studies for wearable devices are briskly being carried out to find new markets, such as virtual reality devices. In this paper, a head-mounted display (HMD) which provides expanded virtual images before human eyes by enlarging images of a small display was designed, and the tolerance analysis method for a focus-adjustable HMD based on afocal optical systems was studied. There are two types of HMDs: a see-through type that allows the user to view the surroundings, and a see-close type where the user can only view the display screen; the former is used in this study. While designing the system, we allowed a lens within the system to be shifted to adjust its focus from +1 to -4 D (diopters). The yield of the designed systems was calculated by taking the worst-case scenario of a uniform distribution into account. Additionally, a longitudinal aberration was used rather than MTF for the tolerance analysis with respect to system performance. The sensitivity of the designed system was calculated by assigning a certain tolerance, and the focus lens shift was calculated to adjust the image surface variations resulting from the tolerance. The smaller the tolerance, the more expensive the unit price of the products. Very small tolerances may even be impossible to fabricate. Considering this, the appropriate tolerance was assigned; the maximum shift of the focus lens in which the image surface can be adjusted was obtained to find the changes in aberration and a good yield.

• 한국전기전자재료학회논문지
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• 제37권5호
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• pp.465-475
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• 2024

Due to changes in the form factor of display panels and touch screen panels in various devices, capacitive touch systems have evolved to address various issues such as low power consumption, noise immunity, and small chip size. Furthermore, some devices have applications that use a stylus. Since the stylus operates similarly to a finger touch, it encounters similar issues. Recent research trends focus on addressing key issues such as noise, which is primarily caused by the self-capacitor formed between the display cathode and the touch screen panel. In this paper, Various research papers discussing methods to eliminate external noise will be reviewed. These advancements enhance noise immunity in touch systems, making it easier to use thinner and more flexible panels. These progress make touch technology more versatile and reliable in various applications.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.I
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• pp.105-108
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• 2005

We demonstrate an electro-optical device based on the flexoelectric effect of a short-pitched cholesteric liquid crystal. By using a dual-frequency switchable nematic, a small amount of chiral dopant and a small amount of phase-separated polymer localized on the surface, we were able to create a device that operates in amplitude (flexoelectric) and phase(dielectric) modes. At high frequency the dual frequency liquid crystal suppresses the phase mode at higher voltage, which improves the switching speed, and thereby preserving the in-plane-switching mode.

• 정보처리학회논문지B
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• 제9B권5호
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• pp.523-532
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• 2002

최근 들어 인터넷이 광범위하게 보급되고 무선 이동통신 기술이 눈부시게 발전하면서 무선 단말기를 통한 인터넷 상에서의 정보 검색이 시간과 장소에 구애받지 않고 가능하게 되었다. 하지만 무선 단말기를 통한 인터넷의 접근은 단말기 자체의 제한과 무선망의 제한으로 인해 기존 데스크 탑 컴퓨터의 유선 상에서 보다 웹 페이지 탐색에 많은 어려움을 가진다. 본 논문은 이러한 제약을 완화시키기 위해서 웹 페이지로부터 페이지 정보를 축소한 페이지 맵을 생성하여 웹 정보를 쉽게 검색할 수 있게 하는 페이지 재구성 시스템을 제안한다. 그리고 대표적인 웹 사이트에 대한 실험을 통해 제안한 시스템이 무선 단말기 상에서 빠른 웹 페이지 로딩 속도를 보장하며, 작은 스크린을 통해서도 효율적인 웹 탐색이 가능함을 보인다.

• 한국HCI학회논문지
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• 제4권2호
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• pp.9-16
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• 2009

최근 3차원 입체 디스플레이에 대한 관심이 증가하고 있다. 무안경식 다시점 입체 디스플레이(Multiple-view Autostereoscopic Display)는 관찰자가 셔터 글래스(Shutter glasses)또는 HMD(Head Mounted Display)와 같은 특별한 장치를 착용하지 않고도 여러 시점(Multiple-view)에서 입체 영상을 볼 수 있어 가상현실(Virtual Reality), 모바일, 3D TV 등의 분야에서 각광 받고 있다. 하지만, 디스플레이 설계 시 정해진 거리와 시역 내에 관찰자가 위치해 있어야만 입체 영상을 볼 수 있다는 문제점이 있다. 본 연구에서는 무안경식 다시점 입체 디스플레이 시스템을 구축하여 이 시스템에서 관찰자의 시점 변경에도 실시간으로 자연스러운 3차원 입체 영상을 보여 주기 위한 효율적인 GPU기반 렌더링 기법을 제안한다.

• Journal of Information Display
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• 제9권2호
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• pp.18-21
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• 2008

We report on white organic light-emitting diodes (WOLEDs) based on single white dopants, $Ir(pq)_2$($F_2$-ppy) and $Ir(F_2-ppy)_2$(pq), where $F_2$-ppy and pq are 2-(2,4-difluorophenyl) pyridine and 2-phenylquinoline, respectively. The similar phosphorescent lifetime of two ligands lead to luminescence emission in two ligands simultaneously. However, the emission color of the devices was reddish, because the energy was not transferred efficiently from the 4,4,N,N'-dicarbazolebiphenyl (CBP) to the $F_2$-ppy ligand, due to the small band gap of the CBP. Accordingly, we used 1,4-phenylenesis(triphenylsilane) (UGH2) with a large band gap, instead of CBP as the host material. As a result, it was possible to adjust the emission color by the host material. The luminous efficiency of the device with $Ir(F_2-ppy)_2$(pq) doped in UGH2 was about 11 cd/A at 0.06 cd/$m^2$.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.I
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• pp.609-613
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• 2005

Advanced mobile communication devices require a bright, high information content display in a small, light-weight, low power consumption package. In this paper we will outline our progress towards developing such a low power consumption active-matrix flexible OLED ($FOLED^{TM}$) display. Our work in this area is focused on three critical enabling technologies. The first is the development of a high efficiency long-lived phosphorescent OLED ($PHOLED{TM}$) device technology, which has now proven itself to be capable of meeting the low power consumption performance requirements for mobile display applications. Secondly, is the development of flexible active matrix backplanes, and for this our team are employing poly-Si TFTs formed on metal foil substrates as this approach represents an attractive alternative to fabricating poly-Si TFTs on plastic for the realization of first generation flexible active matrix OLED displays. Unlike most plastics, metal foil substrates can withstand a large thermal load and do not require a moisture and oxygen permeation barrier. Thirdly, the key to reliable operation is to ensure that the organic materials are fully encapsulated in a package designed for repetitive flexing. We also present progress in operational lifetime of encapsulated T-PHOLED pixels on planarized metal foil and discuss PHOLED encapsulation strategy.

• 반도체디스플레이기술학회지
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• 제9권1호
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• pp.55-59
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• 2010

In this study, we developed nonvolatile residue (NVR) real-time monitoring system to measure the nonvolatile residue particle in ultra pure water (UPW). This device has a capability of measuring 4 different channels, i.e., 10 nm, 30 nm, 50 nm, and 100 nm. Until now, the light scattering method to detect RAE(residue after evaporation) was the only choice. However, this method can detect RAE larger than ca. 50 nm. In ultra pure water, RAE particles are usually very small and hard to detect with conventional laser scattering devices. To detect very small RAEs, a new system is developed and tested. The system consists of an atomizer that generates RAE particles and a four channel condensation particle counter (CPC). During the several months' operation in manufacturing line, the system was successfully tested and showed reliable results.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 춘계학술대회논문집
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• pp.463-466
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• 2005

While recent display devices are becoming light and slim, the size of a screen is especially the important issue in the field of display devices. Furthermore, it is also required that the projection TV, a large screen display device, be able to represent higher resolutions as the digital broadcasting is set off. In order to realize high resolutions in a DLP projection TV, the number of pixel on DMD should be increased. However, a large number of pixels make it difficult to realize resulting small sized pixels and this cause the increase in cost. Therefore, we propose a simple and improved pixel enhancement actuator using the existing DMD by offsetting half pixels repeatedly in the vertical direction.

• 한국인쇄학회지
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• 제29권2호
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• pp.71-82
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• 2011

Electronic display markets has been developed. The cathode ray tube of brown form recently celebrated their 100th by first display. Also LCD of flat form recently celebrated their 25th by second display and it has advantage of small volume, lower consumption power. But FPD has problem that is property of brittle and noncarrying by glass substrate. Therefore the arrival of portable electronics devices has put an increasing premium on durable, lightweight and inexpensive display components. It is flexible display by third display. Also electronics field such as printed wiring board, RFID, membrane switch prefer flexible display. The conductive pattern can be used mostly in field of electronic displays and electronics. This manufacture of conductive pattern in present used is screen printing. The the conductive pattern. It has advantages of flexibility, high conductivity, drying in low temperature, good conductivity. screen printing has problem that is low productivity and use not flexible substrate because of high fire temperature. This study was developed novel method to form the conductive pattern. It has advantages of flexibility, high conductivity, drying in low temperature, good conductivity.