• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.157-158
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• 2011

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.25 no.1
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• pp.48-52
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• 2012

The charged particle type display device is a kind of the reflectivity type display and shows an image by absorption and reflection of external light source. The charged particle is important factor for driving of the display and quantity of charge per mass of the charged particle determines the driving voltage, contrast ratio, response time, etc. But it is easy for the charged particles to be damaged in the putting process of the display and the damages cause lumping phenomenon of the charged particles. Because the lumping phenomenon makes high driving voltage, low quality of optical properties, short life time, etc, so the charged particles must be filled by stable putting methods. In this paper, we filled the charged particles into the panels by electric fields to improve the electrical and optical characteristics of the display. Also, we analyzed the driving characteristics of the charged particles according to the applied putting voltages.

• Journal of the Semiconductor & Display Technology
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• v.9 no.4
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• pp.87-91
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• 2010

Charged micro-particles are widely used as the key components for many electrical applications such as an e-paper, a touch panel, a printer toner and an electronic ink. Among them, the e-paper is an emerging reflective type display using the charged particles that has the advantages of the extremely low power consumption and sunlight readability. To create images on the e-paper, we confine black positively-charged and white negatively-charged particles between bottom and top electrodes and selectively apply the electric field. When the Coulomb force by an applied electric field is greater than the adhesion force between the charged particle and the electrode, the particles' transition happens resulting in the change of color between black and white. Therefore, the adhesion force is a very important factor for designing and estimating e-paper's operation. In this study, we constructed a basic model for particle's transition and an adhesion force equation describing particle's transition with three different forces: electrostatic image force, Van der Waals force and gravitational force. The simulation results showed that the gravitational force is negligible for the interesting range for the charge and the radius, and the adhesion force can be strongly dependent on the particle's charge and radius.

• Journal of ILASS-Korea
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• v.7 no.2
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• pp.7-15
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• 2002

A particle flow visualization, electrostatic charging measurement and separation of triboelectrically charged particles in the external electric field by a fluidized bed tribocharger are conducted for the removal of PVC particles from mixed waste plastics. The laboratory-scale triboelectrostatic separation system consists of the fluidized bed tribocharger, a separation chamber, a collection chamber and a controller. PVC and PET particles can be imparted negative and positive surface charges respectively due to the difference of triboelectric charging series between particles and particles in the fluidized bed tribocharger, and can be separated by passing them through an external electric field. To visualize these charged particles, He-Ne laser is used with cylindrical lenses to generate a sheet beam. In the charging measurement, the particle motion analysis system (PMAS), capable of determining particle velocity and diameter. is used to non-intrusively measure particle behavior in high strength electric field. The average charge-to-mass ratios of PVC and PET particles are $1.4\;and\;1.2{\mu}C/kg$, respectively. The highly concentrated PVC (91.9%) can be recovered with a yield of about 96.1% from the mixture of PVC and PET materials for a single-stage processing. The triboelectrostatic separation system using the fluidized tribocharger shows the potential to be an effective method for removing PVC from mixed plastics for waste plastic recycling.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.1
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• pp.63-67
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• 2008

The charged particle type display is a kind of electronic paper showing information images using positive and negative charged particles ($<10{\mu}m$). In this work we used yellow(-) and black(+) particles which are respectively addressed to the cells of a upper and a rear substrate by using electric field. Our independent addressing method has strong points compared to the mixed particle putting method. The packaging with two orthogonal substrates and the aging process is followed by addressing process. The panel is sequentially driven by matrix method for each 4-unit cells. Layers of particles are controlled by barrier ribs and must be addressed to minimum 2 layers.

• 한국정보디스플레이학회:학술대회논문집
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• 2000.01a
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• pp.139-140
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• 2000

The origin of the display current in the surface conduction electron emitter displays has been verified in the calculation of the electron trajectory. Some electrons move directly toward the display surface as an anode current which is generated due to the inertial force of electron motion along the curved electric field lines with a small curvature near the fissure area..

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.498-501
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• 2009

Electrophoretic displays (EPDs) are attracting considerable attentions as a paper-like display. Especially, Electrophoretic cell consists of micron-sized, charged particles dispersed in a viscous fluid. When an external electric field is applied, the charged particles move with a speed proportional to the particle mobility and the local field strength. In electrophoretic displays fast switching times are required, so knowing the particle mobility is very important. In this paper, we study a novel simulation for calculating the particle motions submerged in a viscous fluid for horizontal switching electrophoretic cell.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.53-54
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• 2007

Charged particle type display using particles which have opposite charge and color is based on effect of reversible optical property due to electric field. we designed mask pattern for fabrication of the charged particle type display based on glass substrate and investigated cell gap dependent of driving voltage and selectively driving method. the panel driven by our selectively driving method, we could obtain image which had vary little crosstalk caused by electrical interference and conform the last image maintained by memory effect without additional voltage.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.22 no.2
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• pp.169-173
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• 2009

We studied driving characteristics according to the ratio of mass and charging (m/q) value for charged toner particles with black and yellow color in charged particle type display panel. After biasing rectangle pulse to the transparency electrodes of putted panel with toner particles, its response time and contrast ratio are simultaneously measured using a laser as a optical source, photodiode as a detector and reflective system. As a results, contrast ratio is largest at the shortest response time region which is different to the particle because of m/q. We proposed relational equation for response time, m/q, cell gap and biasing voltage. It has not been studied and reported to analyze the relationship of response time, biasing voltage, lumping phenomena, cell gap, and contrast ratio for toner particle type display.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.23 no.3
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• pp.299-310
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• 1999

Effect of electrostatic and inertial forces on the pre-charged particle deposition was theoretically and experimentally studied by introducing the inertia impactor subjected to an electric field. To derive the analytic solution, we assumed that a flow was an ideal stagnation flow, a particle had saturation charges, and the electric field within the test section was uniform. On the other hand, $Al_2O_3$ particle groups were used as the test particles, which mean sizes were $1{\mu}m$, $3{\mu}m$, and $5{\mu}m$. To measure the deposition efficiency, the light scattering method was used. The results showed that the deposition efficiency was minimized at a certain nozzle velocity as increasing the nozzle velocity, only if the electric force was applied. As the electric field strength increased, $Stk_{50}{^{1/2}}$ was decreased, and its decreasing rate was reduced with increasing the flow velocity. Moreover the existence of electric field was against the cut-off performance of the inertia impactor.