• Journal of the Optical Society of Korea
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• v.13 no.2
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• pp.256-260
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• 2009

The optical performance of the reflective polarizer was investigated over three kinds of direct-lit backlights and/or different configurations of the optical sheets. The optical gain factor achieved by using the reflective polarizer increased as the diffuse nature of the optical sheet was enhanced, because of the more efficient polarization conversion. In addition, the gain factor decreased substantially in flat-lamp backlights compared to tubular-lamp backlights, which was ascribed to the high loss factor during the polarization recycling process due to the complex structure and large area of flat lamps. All these results suggested that reducing the loss factor of the backlight is very important for efficient polarization conversion and thus high optical gain of the reflective polarizer.

• Proceedings of the Korean Vacuum Society Conference
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• 1999.07a
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• pp.227-227
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• 1999

Plasma display panel(PDP) is a leading technology for large-area flat panel displays. A current issue in operating the PDP cell is that the efficiency of the PDP cell is very low. To increase the efficiency of the PDP cell, the visible light needs to be maximized and the power consumption minimized. Since the excited xenons are related to the production of the visible light, it is important to optimize the cell geometry and the gas composition that produce the excited xenons more efficiently. A 2D-fluid code (FL2P) is developed and used to simulate the plasma dynamics and the radiation transport in the PDP cell. The cell is optimized with the code for various operating conditions and cell dimensions such as the voltage pulse, electrode length, electrode spacing, gap size, dielectric constant, gas mixture ratio, pressure, and pulse duration.

• 한국정보디스플레이학회:학술대회논문집
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• 2002.08a
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• pp.770-772
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• 2002

A new dry-processing method of organic gate dielectric film in field-effect transistors (FETs) was proposed. The method use vapor deposition polymerization (VDP) that is continuous and low temperature process. It has the advantages of shadow mask patterning and dry processing in flexible low-cost large area applications. Here, 80 nm-thick Al as a gate electrode was evaporated through shadow mask. Gate insulators used two different polyimides. The one material was 4,4'-oxydiphtahlic anhydride (ODPA) and 4,4'-oxydianiline (ODA). Another was 2,2-bis(3,4-dicarboxyphenyl) Hexafluoropropane Dianhydride (6FDA) and 4,4' -oxydianiline (ODA). These were co-deposited by high-vaccum thermal-evapora and cured at 150 $^{\circ}C$ for 1 hour, respectively. Pentacene as a semiconductor and 100 nm-thick Au as a source and drain electrode were evaporated through shadow mask.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.589-590
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• 2006

Recently, research for the micro printing technology has begun to get into the spotlight. It is due to the superior price competitiveness to existent semi-conductor process for manufacturing some parts of display unit, electronic paper, RF-ID information device, and so on. This paper present screen printing process not for paper publication but for parts of electronics such as PDP wall, LCD CF, and so on. There are two major issues. The first one is how to get a fine and even line pattern. The other one is how to get the same patterns in large area. In this research, we present the design, equipment, and process control of screen printing in order to overcome these issues.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.203-203
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• 2012

The SWCNTs network are formed on various plastic substrates such as poly(ethylene terephthalate) (PET), polyimide (PI) and soda lime glass using roll-to-roll printing and spray process. Selective patterning of carbon nanotubes film on transparent substrates was performed using a femtosecond laser. This process has many advantages because it is performed without chemicals and is easily applied to large-area patterning. It could also control the transparency and conductivity of CNT film by selective removal of CNTs. Furthermore, selective cutting of carbon nanotube using a femtosecond laser does not cause any phase change in the CNTs, as usually shown in focused ion beam irradiation of the CNTs. The patterned SWCNT films on transparent substrate can be used electrode layer for touch panels of flexible or flat panel display instead indium tin oxide (ITO) film.

• 한국정보디스플레이학회:학술대회논문집
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• 2000.01a
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• pp.187-188
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• 2000

The conventional firing process method for the transparent dielectric layer in PDP Technology has disadvantages of low through put, high power consumption and large process area. We propose the rapid thermal scinterring (RTS) method as new process method to overcome these disadvantage characteristics. As the experimental result of this method, the optic transmittance(wavelength : 600nm) rate of transparent dielectric layer was more improved than conventional furnaces under the optimized gas supplying. Further, it was certified this method had the best conditions on the firing process of the PDP transparent dielectric layer.

• 한국정보디스플레이학회:학술대회논문집
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• 2000.01a
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• pp.223-224
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• 2000

As technology level of TFT-LCD advances, application to TV becomes an emerging important area for LCD makers. In this paper, we review current LCD technology level to be used in TV such as liquid crystal response behavior, color accuracy, contrast ratio, brightness and panel size. Based on the understanding of current limitations in LCD compared with CRT, the improvement plan to render 'near perfect motion picture' reproduction with LCD is proposed. Digital TV is a great opportunity for digital LCD panels, but we have to solve remaining technical and cost issue in order to be competitive with other large size TV technologies such as PDP, CRT or projection type. In preparing the upcoming digital TV era with advanced TFT-LCD, the hurdles and prospect of larger size LCD-TV panels will be discussed.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07a
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• pp.330-333
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• 2005

We investigated the liquid crystal (LC) alignment phenomena using a-C:H and a-C:F:H thin films. Homogeneous alignment is obtained using ion beam treated hydrogenated amorphous carbon (a-C:H) thin films. Homeotropic alignment is obtained using F treated a-C:H thin films, namely, fluorinated amorphous carbon (a-C:F:H) thin films. We investigated the relationship between the surface properties of amorphous carbon based alignment layer and LC alignment phenomena.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07a
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• pp.558-561
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• 2005

In-situ photopolymerization of alkyl acrylate monomers in the presence of a nematic fluid provides a cellular matrix of liquid crystalline droplets in which the chemical structure of the encapsulating polymer exerts control over the alignment (anchoring) of the liquid crystalline molecules. Control is obtained by variation of the alkyl side chains and through copolymerization of two dissimilar monofunctional acrylates. Two monofunctional acrylates with opposing tendencies on copolymerization provide control over the tunability of anchoring over a wide temperature range. Using various acrylates we show that a uniform vertical alignment can be achieved over a large area. Utilizing this technique and a nematic with negative dielectric anisotropy, we have fabricated highly flexible liquid crytal based devices, with high contrast and fast response time, without using any alignment layer.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.1486-1489
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• 2009

Micro wall is fabricated using iterative screen printing that it is able to fabricate the pattern as low cost, simple process, formation of pattern at large area on the various substrates. In the process of micro wall fabrication using screen printing, the printing result with pressure change in process and improvement of surface roughness using hydrophillic plasma treatment are included. Height of micro wall increase linearly and precision of iteration is very high. Error rate of printed pattern width is very high, but change rate of width is under 10 %. Fabricated micro pattern have minimum width $48.75{\mu}m$ and maximum height $75.45{\mu}m$ with aspect ratio 1.55.