• Management & Information Systems Review
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• v.37 no.2
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• pp.63-85
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• 2018

Electronic displays have developed as instruments that function as windows of information to satisfy the bidirectional needs of electronic device manufacturers and users. The cathode-ray tube (CRT) display once dominated the display industry. Now, the liquid crystal display (LCD) is dominant, and promising displays are competing to become the next-generation display. Displays reflect the characteristics of the information and communication technology (ICT) industries, such as technological changes, innovative features, and competitive dynamics, and have technologically evolved to dominate the industry and market through various ICT devices. This research utilizes a dominant design concept and examines the case of the flat-panel display industry to propose a comprehensive framework, which considers technological, organizational, and environmental characteristics, of the determinants influencing dominance in the technology-intensive ICT industry. The results show that a dominant design in the flat-panel display industry emerges from technological competition among several designs, based on technological characteristics and market acceptance, and dominates the industry and market by various environmental factors. Our results emphasize the difference between generic technologies and the speed of technological innovation and expand the understanding of the emergence of a dominant design. Furthermore, this paper suggests practical implications for establishing a competition strategy and strategic guidance for other ICT industries as well as the display industry.

• Design & Manufacturing
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• v.2 no.2
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• pp.29-32
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• 2008

A back light unit (BLU) is a key module of a thin film transistor liquid crystal display (TFT-LCD), frequently utilized in various mobile displays. In this study, we experimentally characterize transcription and optical properties of concave and convex microlens arrays (MLAs) of light guide plate (LGP) fabricated by injection molding with polycarbonate as a LGP substrate material. Nickel mold inserts were manufactured by electroforming on the MLA which was fabricated by the thermal reflow of photoresist microstructures patterned by UV-photolithography. For the case of convex microlens, the height of replicated microlens was less than that of the mold insert while maintaining almost the same microlens diameter of the mold insert as the location of the microlens is far from the gate. In contrast, for the concave microlens, the diameter of replicated microlens was larger than that of mold insert, while showing almost the same microlens height as the mold insert. From the optical examination of replicated convex and concave MLAs, it was found that a higher luminance of the LGP was achieved by the concave MLAs compared to the convex MLAs (about 30% enhancement in this case)due to the utilization of a larger amount of light provided by the light sources.

• International Journal of Precision Engineering and Manufacturing
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• v.7 no.1
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• pp.51-56
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• 2006

A computer code was developed to simulate both the thermal stresses introduced during the post-filling stage and the in-plane deformation after ejection process by finite element method based on the plane stress theory. The computer simulation was applied to the mold design of a 2 inch light guide plate (LGP) for thin film transistor (TFT)-liquid crystal displays (LCD). With injection molding experiments based on the design of experiments (DOE) technique, the influences of the processing conditions in injection molding on brightness and uniformity of the LGP were investigated, and the optimal processing parameters were selected to increase the brightness and uniformity. The verification experiment showed that the brightness and uniformity of the LGP were increased dramatically under the selected optimal processing conditions.

• International Journal of Precision Engineering and Manufacturing
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• v.1 no.1
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• pp.56-61
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• 2000

We present a fast inspection method of machine vision for in-line quality assurance of liquid crystal displays(LCD) and plasma display panels(PDP). The method incorporates an optical spatial filter in the Fourier plane of the imaging optics to block the normal periodic pattern, extracting only defects real time without relying on intensive software image process. Special emphasis is on designing a collimated white light source to provide high degree of spatial coherence for effective real time Fourier transform. At the same time, a low level of temporal coherence is attained to improve defect detection capabilities by avoiding undesirable coherent noises. Experimental results show that the proposed inspection method offers a detection accuracy of 15% tolerance, which is sufficient for industrial applications.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.699-702
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• 2006

We have developed twist nematic liquid crystal displays (TN-LCDs), of which the viewing angle can be controlled. The TN-LCDs have the function of switching between the wide viewing mode and narrow viewing angle mode using two tilted LC layers. Tilt angles of the two LC layers, $14^{\circ}$ and $60^{\circ}$ were required in both wide viewing angle and narrow viewing angle modes, respectively. In this way, the viewing angle range in terms of contrast ratio 5:1 can be switched from $120^{\circ}$ to $60^{\circ}$.

• Korean Journal of Materials Research
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• v.17 no.7
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• pp.352-357
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• 2007

Since a pattern defects "repair" system using a diode pumped solid state laser for Flat Panel Display (FPD) was suggested, a lot of laser systems have been explored and developed for mass-production microfabrication process. A maskless lithography system using 405 nm violet laser and Digital Micromirror Device (DMD) has been developed for PDP and Liquid Crystal Display (LCD) Thin Film Transistor (TFT) photolithography process. In addition, a "Laser Direct Patterning" system for Indium Tin Oxide (ITO) for Plasma Display Panel(PDP) has been evaluated one of the best successful examples for laser application system which is applied for mass-production lines. The "heat" and "solvent" free laser microfabrications process will be widely used because the next-generation flat panel displays, Flexible Display and Organic Light Emitting Diode (OLED) should use plastic substrates and organic materials which are very difficult to process using traditional fabrication methods.

• 한국정보디스플레이학회:학술대회논문집
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• 2000.01a
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• pp.71-72
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• 2000

The design of large area thin film transistor liquid crystal displays (TFT-LCDs) requires consideration of cross-talks between the data lines and pixel electrodes. These limits are imposed by the mutual coupling capacitances present in a pixel. The mutual coupling capacitance causes a pixel voltage error. In this study, semi-empirical model, which is adopted from VLSI interconnection capacitance calculations, is used to calculate mutual coupling capacitances. With calculated mutual coupling capacitances and arbitrary given image pattern, the root mean square (RMS) voltage of pixel is calculated to see vertical cross-talk from the first to the last column. The information obtained this study can be utilized to design the larger area and finer image quality panel.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.637-640
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• 2009

The LCD based on Kerr effect is highly interesting because it uses an optically isotropic state with no need of alignment layer and it shows sub-millisecond response time. The problem of the device is that it requires very high operating voltage and the transmittance is relatively low compared with other LCDs that use nematic LC. In this work, we study on various electrode structures and driving method which can lower operating voltage.

• Proceedings of the KIEE Conference
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• summer
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• pp.1208-1210
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• 2004

The Cold-Cathode Fluorescent Lamps (CCFL) are widely used to illuminate the liquid crystal displays(LCD) used in many battery powered instrument. This paper presents analysis of fly-back converter for universal-line applications($90\sim265Vac$) and half-bridge type resonant inverter for CCFL drive for stable characteristic and life improvement of fluorescent lamp operation frequency is higher than resonant frequency for safe operation. The validity of this study was confirmed from the simulation and experiential result.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.231-236
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• 2004

The area of flat glass panel displays such as LCD (Liquid crystal display) and PDP (Plasma display panel) has been increased more than 2 $\times$ 2 m$^2$ for productivity improvement. However, such a large panel area incurs large panel deflection during panel transfer using robots or AGV (Automated guided vehicle) systems. Therefore, electronic industries are making an effort to find an alternative transfer system for the large glass panels with small deflection. The air conveyor with porous pads is one plausible solution, but it becomes expensive because the large porous pads cost much and air consumption increases as the panel area increases. In this work, a simple air slit levitating conveyor was devised to lower the equipment cost and to reduce the air consumption of system. The air flow model between the LCD glass panel and conveyor was constructed and its validity was verified by experiments. To minimize the air consumption, the conveyor dimensions were optimized, and the air consumptions between the air conveyors with the air slit and that with the porous pad were compared.