• Journal of the Korean Institute of Telematics and Electronics A
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• v.32A no.10
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• pp.35-42
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• 1995

In this paper the driving-condition-dependent optical transmission characteristics of an STN LCD are studied. The optical transmission properties are measured for the applied voltage waveform is varied. Also, the optimum ranges of the M signal frequency and the frame frequency are investigated. An LCD is modeled by the equivalent circuit to study the effect of the parameter variation on the frequency response.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.1725-1728
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• 2006

Flat fluorescent lamp(FFL) is used as a light source for LCD TV backlight and is composed of many discharge channels but each channel may not be turned on simultatneouly especially at cold temperature. The simultaneous start of each lamp channels of FFL was accomplished by driving FFL with specially designed voltage and currnet waveforms without sacrificing the inverter efficency.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.25 no.11
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• pp.906-909
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• 2012

The address discharge characteristics of a open dielectric structure compared with the conventional panel structure are investigated by measuring the discharge firing voltage. The open dielectric structure could easily produce the discharge between the scan and the sustain electrodes by erasing the dielectric layer between two electrodes. Due to the changes in the discharge firing characteristics of the open dielectric structure between the two sustain electrodes, the conventional reset waveform including the address waveform needs to be modified. The modified driving waveform suitable for the open dielectric structure is proposed and examined in AC PDP.

• Proceedings of the KIEE Conference
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• 1989.07a
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• pp.16-20
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• 1989

In this paper, we describe the optimal driving method and magnetic flux distribution of permanent magnet which enhance torque characteristics in small-sized 3-phase brushless DC motors. The disadvantages of conventional $120^{\circ}$ constant current drive method are torque ripple, switching noise and spike voltage due to the inductance of stator coil. This shortcommings can be avoided by the switching slew-rate of driving current which is called linear voltage driving method. The aim of this study is to analyze linear voltage driving method quantatively and to determine optimal drive current waveform through computer simulation. The selection of commutation angle and slew rate of a new driving current at switching instants makes torque ripple index minimize and average torque maximize. And the validity of this new driving method was assured by Fourier analysis. Considering two dimensional nonlinear magnetic flux distribution on the permanent magnet, we suggest optimal flux distribution according to the presented driving method which improves torque characteristics.

• Journal of Information Display
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• v.3 no.4
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• pp.1-3
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• 2002

The antiferroelectric liquid crystal display (AFLCD) is a unique display that can at demonstrate a moving image perfectly the passive matrix driving scheme. We optimised driving the waveform and introduced a dual-driving method. Also, by improving this driving method and using line inversion method, we realize the AFLC display of high image quality with $160(RGB){\times}240$, 32768 colors, crosstalk free and flicker free contrast ratio is greater than 60:1, and the brightness is above 200 $cd/m^2$.

• 한국정보디스플레이학회:학술대회논문집
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• 2002.08a
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• pp.545-547
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• 2002

The antiferroelectric liquid crystal display (AFLCD) is unique display that can show the perfect moving image using the passive matrix driving scheme. We optimized the driving waveform and introduced the dual driving method. Also, by improving this driving method and using line inversion method, we realized AFLC display with high image quality, which has 160(RGB)${\times}$240, 32768colors, crosstalk free and flicker free. The contrast ratio is greater than 60:1, and the brightness is above 200cd/$m^2$.

• Proceedings of the KIEE Conference
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• 1987.11a
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• pp.527-529
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• 1987

This paper presents a study on the driving characteristics or delta inverter driving induction motor control systems based on the microprocessor. Delta inverter is a novel circuit which uses only three power transistor. Requiring approximately hair the components or a conventional bridge inverter it therefore has a merit of coat and Simplicity. The basic operating principles of the delta inverter and conventional bridge inverter are argued, using resistive and inductive load. Sinusoidal PWM method uses to reduce the harmonic components of its output waveform to acceptable levels.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.5
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• pp.851-858
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• 2017

In this study, the voltage control system of a single phase full bridge inverter was designed based on the SPWM driving method. The voltage control system consists of a single-phase full-bridge inverter, a PI controller for linearly compensating the error between the reference voltage and the output voltage, a PWM driving circuit for generating the gate signal using the SPWM method from the controller signal, and an LC filter for filtering the inverter output voltage waveform into sinusoidal waveform. Finally, the voltage control system of a single-phase full-bridge inverter based on the PWM driving method was modeled using EMTP-RV and by showing that the output voltage accurately converges the reference voltage through several simulation examples, the validity of the control system design was verified.

• Proceedings of the KIPE Conference
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• 2007.11a
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• pp.215-217
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• 2007

Recently, the demand for high definition TV is being increased by beginning of the digital broadcasting. The higher resolution of PDP is, the longer addressing time become, then, the sustain period for display image decreases. Because of the reason, dual-scan method which synchronously write information of an image on top and bottom of the screen is used for the high definition PDP. However, as the price competition of PDP becomes severe, we can`t avoid turning to a single-scan method which uses only a half of an expensive address IC. Accordingly, the sustain period becomes much shorter than prior method. In case of XGA level, it is impossible to display, eventually. In this paper, we are going to prove usefulness by realizing negative reset waveform and the driving circuit for high speed addressing.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.6
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• pp.1157-1165
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• 2009

In AC-PDP, it is necessary to achieve high luminance efficiency, high luminance and high definition by adopting technologies such as high xenon concentration, MgO doping, and long gap. However, it is very difficult to apply above technologies because they make the driving voltage margin reduced. Especially, high Xe concentration technology for high efficacy makes not only the driving voltage margin reduced but also the stability of reset discharge decreased at low temperature. In this paper, we studied temperature and voltage dependent stability of reset discharge and present the experimental results of the discharge characteristics at low temperature. In addition, we suggested the mechanism of bright noise and black noise at low temperature. Finally, we proposed double reset waveform to improve the bright noise and descending scan time method to improve the black noise.