• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.11a
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• pp.578-581
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• 1999

Dot pattern print methods composed of a diffusion film and two prism sheets, have been generally used for backlighting systems of LCDs. However, this methods require complex structures and show high power consumption and optical loss. To improve these disadvantages of conventional backlight units, light guides using highly scattering optical transmissions (HSOT) polymer as scatters, have been introduced. In this study we analyzed multiple scattering effect in light guide by means of Monte carlo simulation based on Mie scattering theory and ray tracing method. As a result it was revealed that scattering intensity depends on the size of scatters. On the other hands, it was shown that scattering efficiency depends on the wavelength of fluorescent lamp as well as the size of scatters.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.795-798
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• 2004

After showing 32 inch two-dimensionally integrated fluorescent lamp (TIFL) and its module at SID '04, 40 inch TIFL and its module of prototype have been developed at the first time. It is the biggest size in the world as well as has a backlight unit without BEF optical film. The luminance of TIFL is 14000 nit at 190 watt power consumption and its luminous efficacy is 51 lumen/watt. The use of TIFL simplifies backlight assembly process and removes high price optical sheets. As a result, LCD TV, used by TIFL, is rapidly going to expand its market share in the large size TV area.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.1058-1061
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• 2004

Recently, According to companies of TFT LCD are making large sized products more and more. In the vortex of Products with a monitor and LCD TV is applied in a technique of a high viewing angle(FFS, IPS, VA). Also, as a high luminance, high speed response time, high degree of a color purity, and so on are continuing to develop a high performance, it is necessary to improve a specific character of high luminance that apply to LCD TV as a LCD BLU. Because a LCD panel for TV usually has a lower resolution that compare to a monitor, the structure of present backlight system can't put out its power even though it has a merit in transmission. Therefore, the examination of improvement about the high luminance direct typed BLU for LCD TV that presupposes several uses of CCFL(Cold Cathode Fluorescent Lamp) or EEFL(External Electrode Fluorescent Lamp)is actively being progressed. Although it is necessary to increase the number of lamps for applying high performance by the direct type, in this case, because we can design the character of luminance for adoption of high performance. We can satisfy with a level of luminance for LCD TV. Accordingly, we analyzed a change of the number of CCFL, mechanical and optical character to produce the direct typed backlight in 32inches spec. Consequently, we achieved luminance of 6597nit,which was including polarization film, and secured the standard for LCD TV.

• Journal of the Korean Society of Radiology
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• v.8 no.5
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• pp.261-264
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• 2014

In this study, $Gd_2O_2S:Tb^{3+}$ was used as the component of the intensifying screen, and this study aims at analysis of fluorescent feature depending on the increase of tube voltage using spectrometer. When the released fluorescence was measured according to the increase of tube voltage, blue, green and red was observed, among which, $^5D_4-^7F_5$ which is applicable to green, was strongest. In addition, when the fluorescent of 50 kVp and 120 kVp were compared, 50 kVp was proved to release only 9.56% fluorescence of 120 kVp. In case when tube voltage which is higher than 100 kVp is used for the X-ray using $Gd_2O_2S:Tb^{3+}$ intensifying screen, the amount and strength of the fluorescence reaching the film increase drastically, so attention is demanded to get images of proper concentration.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.7
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• pp.420-424
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• 2016

In this study, we developed photocatalytic technology to address the emerging serious problem of air pollution through indoor air cleaning. A single layer of $WO_3$ was prepared by using the dry process of general RF magnetron sputtering. At a base vacuum of $1.8{\times}10^{-6}$[Torr], the optical and electrical properties of the resulting thin films were examined for use as a transparent electrode as well as a photocatalyst. The single layer of $WO_3$ prepared at an RF power of 100 [W], a pressure of 7 [mTorr] and Ar and $O_2$ gas flow rates of 70 and 2 sccm, respectively, showed uniform and good optical transmittance of over 80% in the visible wavelength range from 380 [nm] to 780 [nm]. The optical catalyst characteristics of the $WO_3$ thin film were examined by investigating the optical absorbance and concentration variance in methylene blue, where the $WO_3$ thin film was immersed in the methylene blue. The catalytic characteristics improved with time. The concentration of methylene blue decreased to 80% after 5 hours, which confirms that the $WO_3$ thin film shows the characteristics of an optical catalyst. Using the reflector of a CCFL (cold cathode fluorescent lamp) and the lens of an LED (lighting emitting diode), it is possible to enhance the air cleaning effect of next-generation light sources.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.8
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• pp.167-171
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• 2014

While the development of a portable plate panel display, thinning, high color reproduction, high brightness studies have been actively performed. LED, OLED is used as a light source. The research on quantum dot is much accomplished by the material of light source. Such quantum dot is the next generation semiconductor nano fluorescent substance because quantum dot has the high color reproduction and flexible display characteristic. In this study, we presented to method of using the quantum dot for implementation of the plate panel display. Quantum Dot (CdSe/ZnS), having a 100um thickness, is spread in PET barrier film. A Blue LED having a wavelength of 455nm as a light source irradiating light to the optical characteristic of the devices produced and evaluated. Also we presented the possibility for application with the color change film of the LCD.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.9
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• pp.1303-1308
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• 2004

The beef color stability during display of two muscles, m. longissimus thoracis and m. semitendinosus, of Japanese Shorthorn steers (n=14) was compared with that of Japanese Black steers (n=14). The beef color of each carcass was evaluated according to the Japanese Grading Standards at 24 h post mortem. Steak samples from muscles were over-wrapped with PVC film and displayed under fluorescent lights at $4^{\circ}C$ for 9 days. Metmyoglobin percentages of steak samples were determined at days 0, 3, 6 and 9. The overall grade of beef color of the carcasses of Japanese Shorthorn steers was significantly (p<0.05) lower than that of Japanese Black steers. The metmyoglobin percentages during the display of two muscles of Japanese Shorthorn steers were significantly (p<0.05) lower than those of Japanese Black steers. These results suggested that though beef color evaluation of the carcasses of Japanese Shorthorn steers was lower than that of Japanese Black steers, the beef color stability during the display of the muscle of Japanese Shorthorn steers was higher than that of Japanese Black steers.

• Bulletin of the Korean Chemical Society
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• v.33 no.5
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• pp.1608-1612
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• 2012

Singlet oxygen ($^1O_2$) is an important species for oxidation in biological processes. $^1O_2$ is implicated in the genotoxic effect, and plays an important role in the cell-signaling cascade and in the induction of gene expression. However, the rapid detection of $^1O_2$ in biological environments with sufficient specificity and sensitivity is hampered by its extremely low emission probability. Here, a layer-by-layer (LbL) film of CdTe quantum dots (QDs), polymers, and ascorbate have been designed as a rapid, highly selective, and sensitive fluorescence probe for $^1O_2$ detection. Upon reaction with $^1O_2$, the probe exhibits a strong photoluminescence (PL) response even at trace levels. This remarkable PL change should enable the probe to be used for $^1O_2$ detection in many chemical and biological systems and as an environmental sensor.

• Proceedings of the IEEK Conference
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• 2004.08c
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• pp.675-679
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• 2004

The existing conjugated blue emitting material polymer which has been used for the two-wavelength method white-emission has good stability and low operating voltage as merits, but the imbalanced carrier transport has been indicated as problem area. We have introduced a novel blue emitting material having perylene moiety unit with hole transporting ability and blue emitting property and triazine moiety unit with electron transporting ability into the same host chain. We have synthesized N-[p-(perylen-3-y1)pheny1]methacry1 amide (PPMA) monomer and [N-(2,4-dipheny1-1,3,5-triazine)pheny1 methacry1 amide] (DTPM) monomer having blue light-emitting unit and electron transport unit, respectively by three steps. A novel non-conjugated blue emitting material Poly[N -[p­(perylene-3-y1) pheny1] methacry1 amide-co-N-[P-(4,6-dipheny1-1,3,5-triazine-2-y1]pheny1]methacry1 amide] (PPPMA-co-DTPM) copolymer having electron transporting unit was synthesized by the solution polymerization of PPMA and DTPM monomers with an AIBN initiator and showed high yield of $75{\%}$. It was very soluble in common organic solvents, and the fabrication of the thin film using a spin coating method was very simple. The PPPMA exhibited a good thermal stability.

• Journal of the Korean Ceramic Society
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• v.46 no.1
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• pp.24-29
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• 2009

The suspension of $Al_2O_3$ which has long-term stability was made by mechanical milling. Thin films were evaluated and made to use as coating materials. A particle size of the suspension manufactured was 98 nm when 2 mt% nitric acid was added. It indicated that viscosity of the suspension is 12 cps and that it had the long-term stability. Thickness which was from 200 nm to 600 nm of the thin films was able to be made by adjusting draw rate and organic additive. Cracks of thin films at room temperature were prevented by adding Ethyl cellulose from 0.5 wt% to 2 wt%. The thin film heated at $500^{\circ}C$ indicated a hydrophilic property against water and an excellent permeability against a visible ray.