• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.449-449
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• 2007

OLED has many advantages of low voltage operation, self radiation, light weight, thin thickness, wide view angle and fast response time to overcome existing liquid crystal display (LCD)'s weakness. Therefore, It draws attention as promising display and has already developed for manufactured goods. Also, OLED is regarded as a only substitute of flexible display with a thin display. A considerable portion of the light originating film emissive centers buried in a solid film never escapes due to internal reflection at the air-film interface and is scattered as edge emission or dissipated within the solid film This is one of the major reasons why the luminous power efficiency of OLED remains low, in spite of research progress in OLED. Although several ways of overcoming this difficulty have been reported, no comprehensive method has been proposed yet. In this paper, we propose that use of anti-reflective coating layers.

• Information Display
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• v.5 no.1
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• pp.25-30
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• 2004

Poly-Si TFT(Thin Film Transistor) technology are reviewed and discussed. Poly-Si TFTs fabricated on glass using low-temperature process were studied extensively for the application to LCD (Liquid Crystal Display) as well as to OLED(Organic Light Emitting Diode) Display. Currently, one of the application targets of the poly-Si TFT is emphasized on the highly functional SOG(System on Glass). Improvement of device characteristics such as an enhancement of carrier mobility has been studied intensively by enlarging the grain size. Reduction of the voltage and shrinkage of the device size are the trend of AM FPD(Active Matrix Flat Panel Display) as well as of Si LSI, which will arise a peculiar issue of uniformity for the device performance. Some approaches such as nucleation control of the grain seed or lateral grain growth have been tried, so far.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.8 no.2
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• pp.25-31
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• 2009

The image processing methods are widely used in many industrial fields to detect defections in inspection devices. In this study an image processing method was conducted for the detection of abnormal pixels in a OLED(Organic Light Emitting Diode) type panel which is used for small size displays. The display quality of an OLED device is dependent on the pixel formation quality. So, among the so many pixels, to find out the faulty pixels is very important task in manufacturing processing or inspection division. We used a line scanning type BW(Black & White) camera which has very high resolution characteristics to acquire an image of display pixel patterns. And the various faulty cases in pixel abnormal patterns are considered to detect abnormal pixels. From the results of the research, the normal BW pixel image could be restored to its original color pixel.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.1063-1064
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• 2008

We have discovered a new single-layer environmental barrier for OLEDs. In storage at $65^{\circ}C$ and 85% relative humidity, OLED pixels encapsulated with this barrier have half-lives of approximately one year. We describe the fabrication and properties of the barrier, and results of accelerated storage tests.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.1267-1270
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• 2006

Organic light-emitting diode (OLED) display panel with $64\;{\times}\;64$ pixels utilizing the charge-pump (CP) pixel addressing method was fabricated using conventional thin-film processes. Each pixel consists of a-Si:H Schottky diode and $ITO/SiO_2/ITO$ capacitor. It is shown that CP-OLED is technically feasible for information display and a driving voltage below $4V_{pp}$ is enough for nominal operation.

• Electronics and Telecommunications Trends
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• v.38 no.1
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• pp.26-35
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• 2023

Inkjet printing is a typical printing technology with many advantages, such as material cost reduction, noncontact pattern formation without a mask, and process simplification. With the recent and rapid development of ink materials, parts and equipment, and process technologies related to inkjet printing, it is becoming a major process in various areas of the display industry. In particular, for the QD-OLED (quantum dot-organic light-emitting diode) display announced by Samsung Display in 2022, quantum dot pixel production by applying inkjet printing is a key technology. We analyze inkjet printing technology for mass production applied to the display industry and discuss the technology development trends in academia and industry toward the realization of next-generation displays.

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.920-923
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• 2003

We fabricated composite materials as a pellet structure with the various kinds of inorganic material powder. The composite materials were deposited onto the plastic film by the electron beam evaporation and water vapor transmission rates (WVTRs) were measured by the MOCON facility. As a result of WVTRs, the composite materials had lower WVTR value than any other inorganic materials. So, these films were proposed to protect the organic light emitting device (OLED) from moisture and oxygen. We can consider that the composite thin-film is one of the more suitable candidates for the thin-film passivation layer in the OLED. And, we are processing the XRD, XPS and EPMA to analyze the property of the composite material. We will also analyze properties of the current-voltage and luminescence for lifetime both the composite thin-film passivated OLED and non-passivated OLED.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.04a
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• pp.78-80
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• 2006

The hybrid thin-film (HTF) passivation layer composed of the Ultra Violet (UV) curable acrylate layer and MS-31 (MgO:$SiO_2$=3:1wt%) layer was adopted in organic light emitting device (OLEO) to protect organic light emitting materials from penetrations of oxygen and water vapors. The results showed that the HTF layer possessed a very low WVTR value of lower than $0.007gm/m^{2+}day$ at $37.8^{\circ}C$ and 100% RH. This value was within the limited range of the sensitivity of WVTR measurements. And the lifetime of the HTF passivated device became almost three times longer than that of the bare device. The HTF on the OLEO was found to be very effective in protect what from the penetrations of oxygen and moisture.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.1055-1055
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• 2009

The mobility of charge carriers has been investigated in the pristine and phosphorescent materials doped host materials using time-of-flight photoconductivity technique. The field and temperature dependences of the mobility were analyzed with the Gaussian disorder model. Based on these results, we optimized white organic light emitting diodes (WOLEDs) consisting of multi-emitting layers doped with phosphorescent and fluorescent dopants. Especially, we studied the effect of each emitter position and an interlayer on the device characteristics of WOLEDs.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.673-675
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• 2004

This study proposes controller with voltage-compensated drivers for producing gray-scaled pictures on passive matrix organic light emitting diodes (PMOLEDs) panels. The controller includes voltage type drivers so the output impedance of the driver is far less than that of the current-type driver. Its low output impedance provides better electron-optical properties than those of traditional current drivers. A free running clock and a group of counters are applied to the gray-scaled function so that phase lock loop (PLL) circuit can be reduced in the controller. A pre-charge function is used to enhance performance of the luminance of an active OLED pixel. As a result, distribution of the low gray level portion is achieved linear relationship with input data. In this work, the digital part of the proposed controller is implemented using FPGA chips, and analog parts are combined with a digital-analog converter (DAC) and analog switches. A still image is displayed on a $48^{\ast}64$ PMOLEDs panel to assess the luminance performance fir the controller. Based on its cost requirement and luminance performance, the controller is qualified to join the market for driving PMOLEDs panels.