• 한국정보디스플레이학회:학술대회논문집
• /
• 2004.08a
• /
• pp.272-276
• /
• 2004

Great strides in organic light emitting device (OLED) technology have resulted in a number of commercial products. To continue this growth into large area displays, for example televisions, an understanding of the mechanisms that drive the OLED device efficiency and lifetime performance is critical. In this work, we consider maximizing the efficiency lifetime product based on phosphorescent OLED ($PHOLED^{TM}$) technology. We report green PHOLEDs with luminous efficiency of 82 cd/A, 5.7 V and 10,000 hours lifetime at 1,000 cd/$m^2$,red PHOLEDs with CIE of (0.67,0.33), 11 cd/A and 35,000 hours lifetime at 500 cd/$m^2$ and recent progress in blue demonstrating efficiencies of 18 cd/A at 200 cd/$m^2$.

• Electronics and Telecommunications Trends
• /
• v.34 no.2
• /
• pp.10-18
• /
• 2019

Since the introduction of CRT(Cathode Ray Tube) in the 1950s, display technologies have been developed continuously. Flat panel displays such as PDP(Plasma Display Panel) and LCD(Liquid Crystal Display) were commercialized in the late 1990s, and OLED(Organic Light Emitting Diodes) and Micro-LED(Micro-Light Emitting Diodes) are now being developed and are becoming widespread. In the future, we expect to develop ultra-realistic, flexible, embedded sensor displays. Ultra-realistic display can be applied to AR/VR(Augmented Reality/Virtual Reality) devices and spatial light modulators for holography. The sensor-embedded display can be applied to robots; electronic skin; and security devices, including iris recognition sensors, fingerprint recognition sensors, and tactile sensors. AR/VR technology must be developed to meet technical requirements such as viewing angle, resolution, and refresh rate. Holography requires optical modulation technology that can significantly improve resolution, viewing angle, and modulation method to enable wide-view and high-quality hologram stereoscopic images. For electronic skin, stable mass production technology, large-area arrays, and system integration technologies should be developed.

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2013.11a
• /
• pp.237-238
• /
• 2013

The quality of document image captured from electronic display might be worse when it is compared with document image captured from paper. The problem appears because of Moir? noise. This problem can lead to achieve inaccurate intermediate result for further image processing. This paper proposes a method to remove Moir? noise of document images captured from electronic display. The proposed algorithm is separated in two parts. In the first step, it corrects the text area region (foreground) with small area of smoothing. Then, it corrects the background area with large area of smoothing.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2008.10a
• /
• pp.107-108
• /
• 2008

The spectacular development of AMLCDs, been made possible by a-Si:H technology, still faces two major drawbacks due to the intrinsic structure of a-Si:H, namely a low mobility and most important a shift of the transfer characteristics of the TFTs when submitted to bias stress. This has lead to strong research in the crystallization of a-Si:H films by laser and furnace annealing to produce polycrystalline silicon TFTs. While these devices show improved mobility and stability, they suffer from uniformity over large areas and increased cost. In the last decade we have focused on microcrystalline silicon (${\mu}c$-Si:H) for bottom gate TFTs, which can hopefully meet all the requirements for mass production of large area AMOLED displays [1,2]. In this presentation we will focus on the transfer of a deposition process based on the use of $SiF_4$-Ar-$H_2$ mixtures from a small area research laboratory reactor into an industrial gen 1 AKT reactor. We will first discuss on the optimization of the process conditions leading to fully crystallized films without any amorphous incubation layer, suitable for bottom gate TFTS, as well as on the use of plasma diagnostics to increase the deposition rate up to 0.5 nm/s [3]. The use of silicon nanocrystals appears as an elegant way to circumvent the opposite requirements of a high deposition rate and a fully crystallized interface [4]. The optimized process conditions are transferred to large area substrates in an industrial environment, on which some process adjustment was required to reproduce the material properties achieved in the laboratory scale reactor. For optimized process conditions, the homogeneity of the optical and electronic properties of the ${\mu}c$-Si:H films deposited on $300{\times}400\;mm$ substrates was checked by a set of complementary techniques. Spectroscopic ellipsometry, Raman spectroscopy, dark conductivity, time resolved microwave conductivity and hydrogen evolution measurements allowed demonstrating an excellent homogeneity in the structure and transport properties of the films. On the basis of these results, optimized process conditions were applied to TFTs, for which both bottom gate and top gate structures were studied aiming to achieve characteristics suitable for driving AMOLED displays. Results on the homogeneity of the TFT characteristics over the large area substrates and stability will be presented, as well as their application as a backplane for an AMOLED display.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2005.07a
• /
• pp.575-579
• /
• 2005

A beautiful, flexible active-matrix electrophoretic display (AM-EPD) device is reported. The flexible AM-EPD device has a $40.0{\times}30.0\;mm^2$ display area, measures about 0.27 mm in thickness, weighs about 0.45 g and possesses only 20 external connections. The flexible AM-EPD device displays clear black-and-white images with 5 gray-scales on $160{\times}120$ pixels. The display is free from residual image problems, because we use an area-gray-scale method on $320{\times}240$ EPD elements, each of which is driven with binary signals. Each pixel consists of 4 EPD elements. In addition, since the response time of the electrophoretic material is as long as approximately 400 ms and since the display possesses a large number of EPD elements, we have developed a special driving method suitable for changing EPD images comfortably. A complete image is formed on the AM-EPD device, consisting of a reset frame and several, typically 6, image frames.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2011.08a
• /
• pp.148-148
• /
• 2011

Recently, there have been many research activities to develop the large-area plasma source, which is able to generate the high-density plasma with relatively good uniformity, for the plasma processing in the thin-film solar cell and display panel industries. The large-area CCP sources have been applied to the PECVD process as well as the etching. Especially, the PECVD processes for the depositions of various films such as a-Si:H, ${\mu}c$-Si:H, Si3N4, and SiO2 take a significant portion of processes. In order to achieve higher deposition rate (DR), good uniformity in large-area reactor, and good film quality (low defect density, high film strength, etc.), the application of VHF (>40 MHz) CCP is indispensible. However, the electromagnetic wave effect in the VHF CCP becomes an issue to resolve for the achievement of good uniformity of plasma and film. Here, we propose a new electrode as part of a method to resolve the standing wave effect in the large-area VHF CCP. The electrode is split up a series of strip-type electrodes and the strip-type electrodes and the ground ones are arranged by turns. The standing wave effect in the longitudinal direction of the strip-type electrode is reduced by using the multi-feeding method of VHF power and the uniformity in the transverse direction of the electrodes is achieved by controlling the gas flow and the gap length between the powered electrodes and the substrate. Also, we provide the process results for the growths of the a-Si:H and the ${\mu}c$-Si:H films. The high DR (2.4 nm/s for a-Si:H film and 1.5 nm/s for the ${\mu}c$-Si:H film), the controllable crystallinity (~70%) for the ${\mu}c$-Si:H film, and the relatively good uniformity (1% for a-Si:H film and 7% for the ${\mu}c$-Si:H film) can be obtained at the high frequency of 40 MHz in the large-area discharge (280 mm${\times}$540 mm). Finally, we will discuss the issues in expanding the multi-electrode to the 8G class large-area plasma processing (2.2 m${\times}$2.4 m) and in improving the process efficiency.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2004.08a
• /
• pp.923-926
• /
• 2004

Active-matrix field emission display (AMFED) based on carbon nanotube (CNT) emitter and amorphous silicon thin-film transistor (a-Si TFT) is reviewed. The AMFED pixels consisted of a high-voltage a-Si TFT and mesh-gated CNT emitters. The developed AMFED panel showed a high performance with a driving voltage of below 15 V. The low-cost and large-area AMFED approach with a metal mesh technology will be discussed.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2000.01a
• /
• pp.107-108
• /
• 2000

We propose the method which is possible to fabricate the electrodes with the fine pattern and low resistance by photolithography and electroplating. The widths of pattern fabricated were 30, 50, 70 and 100um and the thickness could be up to $10{\mu}m$. The resistivity of the copper electrode electroplated was below $2.0{\mu}{\Omega}$ cm which is about half of photosensitive silver electrode. Dielectric layer was coated on the electrodes by screen printing and the pores harmful to the discharge were not formed after heat treatment. In the viewpoint of resistance and patterning, this method has much higher potential for large area display than other methods like screen printing, photosensitive conductive paste method and sputtering.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2009.10a
• /
• pp.1379-1382
• /
• 2009

The 3D display has been used in optical projection technology to connect twenty mini- projectors with seamless image tiling. In this way, we can improve the projected resolution by reducing each project screen and increase projected area by connect several mini-projectors. In this article, the illumination system uses the LED light source, non- telecentric structure and LCOS panel, and it's total length is less than 10 centimeter. It can build a seamless large display by tiling multiple projectors.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2003.07a
• /
• pp.1135-1138
• /
• 2003

A direct light type backlight for large-area LCD-TVs using External Electrode Fluorescent Lamps (EEFLs) has been developed. The brightness was $450cd/m^{2}$(nit) and the luminous uniformity (max/min) was 1.3. The mechanical design of backlight was optimized and the reliability of lamps was secured. As a result, the possibility of backlight with EEFLs for large area LCD-TVs was sufficiently proved.