• Journal of the Microelectronics and Packaging Society
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• v.30 no.3
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• pp.78-82
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• 2023

A fabrication of smart windows with controllable visible light transmittance in three steps by using λ/2 retardation films based on a reactive mesogen (RM) material and polarizing films is demonstrated. The phase retardation films with a Δn·d value of λ/2 (λ: wavelength) convert the direction of a traveling light to the optical axis of the film symmetrically. In this work, the retardation characteristics according to the RM thickness were evaluated and henceλ/2 phase retardation film can be fabricated. The phase retardation film with Δn·d of 276.1 nm, which is close to λ/2 (=275 nm @550 nm), was fabricated. The light transmittance of a smart window with the structure of (polarizing film)/(glass)/(alignment layer)/(λ/2 retardation film) was measured in the transmission mode, half mode and blocking mode. The evaluation results show that the transmittance of the smart window can be controlled in three steps with 35.8%, 27.8%, and 18.2% at each mode, respectively. In addition, by fabricating a smart window with a size of 15×200 mm², the feasibility of use in various fields such as buildings and automobiles was verified.

• Textile Coloration and Finishing
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• v.16 no.5
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• pp.28-34
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• 2004

The polarizing film application exploits the unique physicochemical properties between PVA(Poly vinyl alcohol) film and CTA(Cellulose triacetate) film. However, hardly any research was aimed at improving the adhesion characteristics of the CTA film by radio frequency(RF) plasma treatment at argon(Ar) gaseous state. In this report, we deal with surface treatment technology for protective CTA film developed specifically for high adhesion applications. After Ar plasma, surface of the films is analyzed by atomic force microscopy(AFM), roughness parameter and peel strength. Furthermore, the wetting properties of the CTA film were studied by contact angle analysis. Results obtained for CTA films treated with a glow discharge showed that this technique is sensitive to newly created physical functions. The roughness and peel strength value increased with an increase in treatment time for initial treatment, but showed decreasing trend for continuous treatment time. The result of contact angle measurement refer that the hydrophilicity of surface was increased. AFM studies indicated that no considerable change of surface morphology occurred up to 3 minutes of treatment time, but a considerable uneven of surface structure resulted from treating time after 5 minutes.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.32 no.5
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• pp.382-386
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• 2019

The alignment characteristics of liquid crystal (LC) molecules on a solution-derived lanthanum zinc oxide (LZO) film under ion-beam irradiation were demonstrated. Using the solution process, an LZO film was fabricated on the glass substrate and cured at $100^{\circ}C$. Afterwards, ion-beam irradiation was performed following the LC alignment method. Using this film, an LC cell was fabricated and the characteristics of the LC alignment were verified. Cross polarizing microscopy and the crystal rotation method were used to investigate the alignment state of the LC molecules on the LZO films. Furthermore, field emission scanning electron microscopy and X-ray photoelectron spectroscopy were used to explore the effect of the ion-beam irradiation on the LZO film. Through these, it was confirmed that the ion-beam irradiation induced surface modification, which demonstrated anisotropic physical and chemical surface characteristics. Due to this, uniform LC alignment was achieved. Finally, the residual DC and anchoring energy of the LC cell based on the LZO films were measured using a capacitance-voltage curve.

• Resources Recycling
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• v.21 no.2
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• pp.53-58
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• 2012

A laboratory study was carried out to recover KI crystals with high purity from a waste solution generated from the production of polarizing film for LCD industry. The waste solution contains 1 to 4% KI, and other impurities such as B, PVA and etc. More than 95% purity of KI crystals were produced through refining process such as vacuum evaporation and fractional crystallization. Most of B compounds and impurities were removed by concentrating the waste solution until KI content reached about 50%. The KI crystals were washed with solvents to remove most of PVA which gave result in producing 99.5% purity of crystals. The overall recovery of KI was about 90% during the concentration process.

• Bulletin of the Korean Chemical Society
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• v.31 no.8
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• pp.2207-2210
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• 2010

This paper describes the preparation and study of thermally stimulated discharge conductivity (TSDC) study of cellulose triacetate (CTA) - multiwalled carbon nanotubes (MWNTs) film thermoelectrets. TSDC has been carried out in the temperature range 308 - 503 K and at four different polarizing fields. The conductivity of the polymer blends increased with increase in temperature showing a semi-conducting behavior. The apparent activation energy also showed a pronounced effect with the increase in the content of MWNTs.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.13 no.3
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• pp.111-117
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• 2014

With the development of technology, the display industry has been focusing on the development of new types of displays, such as bendable and wearable displays. However, the PVA/TAC polarizing film used in the manufacturing of a normal display is associated with low luminance and low efficiency. If the existing polarization film is replaced with a wire grid polarizer, it is possible to reduce the thickness significantly. Moreover enhanced brightness can also be expected. This study confirms the optical properties of the WGP through a simulation.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.29A no.11
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• pp.106-112
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• 1992

In this paper, we analyze the structure characteristics of $As_{40}Se_{50-x}S_{x}Ge_{10}$ system bulk and thin films. As the results of XRD patterns, it identified amorphous state. In order to find the glass transition temperature($T_g$), crystallization($T_c$) and melting point ($T_m$)of bulk sample, it ascertained that TS1gT is 238$^{\circ}C$ in $As_{40}Se_{15}S_{35}Ge_{10}$, and 231$^{\circ}C$ in $As_{40}Se_{25}S_{25}Ge_{10}$ & $As_{40}Se_{50}Ge_{10}$ following the thernal analysis by DSC, DTA, & TGA method. Also it was confirmed the phase seperation of continuous phase and dispertion phase by the optical texture of polarizing microscope and $T_g$ near 20$0^{\circ}C$ in thin film. Therefore, it was found that it occurs the phase seperation of Ge-rich dontinuous phase and Se-rich dispersion phase following the EDS analysis of thin film and the surface SEM photograph.

• Design & Manufacturing
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• v.14 no.2
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• pp.14-20
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• 2020

In OLED panel production process, it is necessary to cut a part of protective film as a preprocess for lighting inspection. The current method is to recognize only the fiducial mark of the cut-out panel. Bare Glass Cutting does not compensate for machining cumulative tolerances. Even though process defects still occur, it is necessary to develop technology to solve this problem because only the Align Mark of the panel that has already been cut is used as the reference point for alignment. There is a lot of defective lighting during panel lighting test because the correct protective film is not cut on the panel power and signal application pad position. In laser cutting process to remove the polarizing film / protective film / TSP film of OLED panel, laser processing is not performed immediately after the panel alignment based on the alignment mark only. Therefore, in this paper, we performed real time inspection which minimizes the mechanism tolerance by correcting the laser cutting path of the protective film in real time using Machine Vision. We have studied calibration algorithm of Vision Software coordinate system and real image coordinate system to minimize inspection resolution and position detection error and edge detection algorithm to accurately measure edge of panel.

• Polymer(Korea)
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• v.24 no.5
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• pp.713-720
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• 2000

A polymer/iodine complex film was prepared using syndiotactic poly(vinyl alcohol) (s-PVA) with number-average degree of polymerization of 900 and syndiotactic diad content of 63.1%. In comparison with atactic-PVA/iodine films, degree of polarization of the s-PVA/iodine film was improved up to over 99% although a lower transmittance was obtained. By soaking in iodine/potassium iodide aqueous solution of a lower iodine concentration and subsequent drawing by 4 times, s-PVA/iodine film of a higher transmittance and degree of polarization was produced. The degree of iodine desorption of the s-PVA/iodine film in water were very low. The crystallinity and the d-spacing and crystal size of (100) plane increased at the early stage of soaking time, however, remained constant or decreased slightly with increasing soaking time. In consequence, s-PVA/iodine complex formation took place mainly inside crystal region at the initial stage of soaking time, whereas it occurred outside crystal region or physical adsorption of iodine dominated after sufficient soaking.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1992.11a
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• pp.73-76
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• 1992

The amorphous phase of bulk and thin film in the As-Se-S-Ge system was observed by X-ray diffraction. Thermal analysis using DSC, DTA and TGA method has been used for the determination of the glass transition temperature, Tg. The glass transition temperature, Tg for the composition were $238^{\circ}C$ in $As_{40}Se_{15}S_{35}Ge_{10}$ and $231^{\circ}C$ in $AS_{40}Se_{25}S_{25}Ge_{10}$ and $As_{40}Se_{50}Ge_{10}$. The phase seperation of continuous phase and dispersive phase was observed by the optical texture of the polarizing microscope. Also, the glass transition temperature of the thin film was near $200^{\circ}C$. As the results of SEM-EDS analysis, the phase transition of the films by thermal treatment and light illumination was the amorphous to amorphous.