• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.14 no.6
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• pp.487-490
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• 2001

Residual DC voltage of the in-plane switching (IPS)-liquid crystal display(LCD) by voltage-transmittance (V-T) hysteresis method was studied. Several IPS-LCD which have different concentrations of cynao LCs and different resistivities of fluorine LCs were fabricated. We found that the residual DC voltage of the IPS-LCD was decreasing with increasing concentration of cyano LCs and increasing with decreasing specific resistivity of fluorine LC materials. The residual DC voltage property can be improved by low molecular weight and high polarity of cyano LC.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.842-845
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• 2006

We studied for high transmittance panel technology in the FFS mode. We found that fine slit of pixel electrode makes increase of panel transmittance, and at the same time this structure has an issue which is increasing operation voltage (Vop). We analyzed the reason of high Vop in the FFS pixel with fine slit using two-dimensional LC analyses. Finally we suggest the solution which has high transmittance with suitable operating voltage.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.656-659
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• 2001

We investigated the residual DC in the in-plane switching (IPS)-liquid crystal display(LCD) by voltage-transmittance (V-T) hysteresis method. Several IPS-LCD which have different concentrations of cynao LCs and different resistivities of fluorine LCs were fabricated. We found that the residual DC voltage of the IPS-LCD was decreasing with increasing concentration of cyano LCs and increasing with decreasing specific resistivity of fluorine LC materials. The residual DC voltage property can be improved by low molecular weight and high polarity of cyano LC.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.32 no.4
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• pp.296-301
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• 2019

A multiple-electrode-type electronic paper film can implement a single color and control the transparency, as it has multiple electrodes in one cell. Therefore, it can be used as a transparent display. In this paper, we explain the structure and driving method of a transparent electronic paper display, and then propose a control method of transmittance. Subsequently, we verify the theory by measuring the transmittance via experiment. Thus, by changing the manner of applying the voltage to three lower electrodes and one upper electrode, transmittance in eight cases could be realized. It was confirmed that the transmittance derived from the experiment could be controlled from a minimum of 6.75% to a maximum of 71.18%.

• Journal of Information Display
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• v.5 no.3
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• pp.18-24
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• 2004

Voltage-dependent transmittance characteristics associated with various cell parameters have been studied in-plane switching liquid crystal display when both common and pixel electrodes are transparent. When both electrodes are opaque, the transmittance is related to only the distance (I) between electrodes. However, where transparent electrode is used, it is influenced not only the 1but also an electrode width (w) and rubbing angle. In addition, these factors are related to operating voltage which shows maximal transmittance. To maximize the light efficiency of the cell and obtain low operating voltage, the above-mentioned cell parameters need to be optimized.

• Korean Journal of Materials Research
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• v.33 no.9
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• pp.372-376
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• 2023

Transparent conductive tungsten (W) doped indium oxide (In₂O₃; IWO) films were deposited at different substrate bias voltage (-V_b) conditions at room temperature on glass substrates by radio frequency (RF) magnetron sputtering and the influence of the substrate bias voltage on the optical and electrical properties was investigated. As the substrate bias voltage increased to -350 V_b, the IWO films showed a lower resistivity of 2.06 × 10^-4 Ωcm. The lowest resistivity observed for the film deposited at -350 V_b could be attributed to its higher mobility, of 31.8 cm²/Vs compared with that (6.2 cm²/Vs) of the films deposited without a substrate bias voltage (0 V_b). The highest visible transmittance of 84.1 % was also observed for the films deposited at the -350 V_b condition. The X-ray diffraction observation indicated the IWO films deposited without substrate bias voltage were amorphous phase without any diffraction peaks, while the films deposited with bias voltage were polycrystalline with a low In₂O₃ (222) diffraction peak and relatively high intensity (431) and (046) diffraction peaks. From the observed visible transmittance and electrical properties, it is concluded that the opto-electrical performance of the polycrystalline IWO film deposited by RF magnetron sputtering can be enhanced with effective substrate bias voltage conditions.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.7
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• pp.738-746
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• 2004

Recently zinc oxide(ZnO) has emerged as one of the most promising transparent conducting films with a strong demand of low cost and high performance optoelectronic devices, ZnO film has many advantages such as high chemical and mechanical stabilities, and abundance in nature. In this paper, in order to obtain the excellent transparent conducting film with low resistivity and high optical transmittance for Plasma Display Pannel(PDP), aluminium doped zinc oxide films were deposited on Corning glass substrate by dc magnetron sputtering method. The effects of the discharge power and doping amounts of $Al_2$$O_3$ on the electrical and optical properties were investigated experimentally. Particularly in order to lower the electrical resistivity, positive and negative bias voltages were applied on the substrate, and the effect of bias voltage on the electrical properties of ZnO:Al thin film were also studied and discussed. Films with lowest resistivity of $4.3 \times 10 ^{-4} \Omega-cm$ and good transmittance of 91.46 % have been achieved for the films deposited at 1 mtorr, $400^{\circ}C$, 40 W, Al content of 2 wt% with a substrate bias of +30 V for about 800 nm in film thickness.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.337-338
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• 2008

We have studied electro-optic characteristics of a high performance liquid crystal display using Fringe In-plane field Switching (FIS) mode. The strong electric fields cause more liquid crystals to reorient almost in plane above and between the pixel electrodes. As a result, the operation voltage is lower and transmittance is higher than those of Fringe Field Switching (FFS) and In-Plane Switching (IPS) modes. Apparently, the transmittance depends on voltage applied at the configurations of FIS mode which are proposed. Therefore, we have studied certain length of between electrodes for maximum transmittance and light intensity.

• Journal of Information Display
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• v.10 no.2
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• pp.62-67
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• 2009

To understand panel driving more accurately, the optical properties and their distributions in the LCD panel itself, excluding the backlight, were investigated by measuring the transmittance of a one-dot pixel as a function of time. First, the behavior of time-dependent transmittance was analyzed, and it was found that the off-state TFT was not in a steady state but in a transient state during the holding period. Second, the time average, max, min, and range values of the transmittance curves were examined by varying the common voltage level and gray scale. Third, the analysis of such properties was expanded to cover those of the entire panel in all the gray scales. Lastly, the relationship between their properties and distributions was also investigated along with the contour plots.

• Applied Chemistry for Engineering
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• v.9 no.4
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• pp.579-584
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• 1998

Polymer dispersed liquid crystal(PDLC) composite films were made by polymerization induced phase separation method using UV-curing to investigate the effect of fabrication conditions, such as photoinitiator concentration, film thickness, polymerization temperature, and electric field during polymerization, etc., on the electro-optic properties. As the amount of photoinitiator increased, the driving voltage of PDLC device increased due to the increase of small-size liquid crystal phases. This was considered as the results from the increased interfacial area between liquid crystal (LC) and polymer matrix, since LC molecules at the interfacial regions were relatively difficult to response for the applied electric field. When the higher molecular weight oligomer (PTDA-1000) was used as matrix, the initial transmittance was observed to be relatively higher than that for the lower molecular weight oligomer (PTDA-250). Saturation transmittance for PTDA-1000 was observed at relatively lower voltage than that for PTDA-250, of which transmittance was not saturated even at 60 V. As polymerization temperature increased, the initial transmittance of resulting PDLC film increased due to the larger LC droplets formation and the more matched refractive index between LC and matrix than those cases for the lower polymerization temperature. Though driving voltage decreased for the thinner film, it was considered that optimum thickness of the film should be maintained to get some practical contrast, which is the ratio of off- and on-state transmittance. Furthermore, electro-optic properties such as initial transmittance, driving voltage, and response time were observed to be considerably affected by application of external field during polymerization.