• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.480-484
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• 2006

We propose a new PDP cell structure named DIDE (Dual Ignition Discharge Electrodes) structure with a long electrode gap to realize a high luminous efficacy. Suggested DIDE structure basically has a long electrode gap $(200{\mu}m{\sim}400{\mu}m)$, nevertheless, because of auxiliary electrodes formed on the front panel, can be driven at relatively low voltage. The discharge characteristic of DIDE structure was much different from that of conventional structure, which was analyzed by IR emission images using IICCD (Image Intensified Charge Coupled Device). The study can explain some particular characteristics of DIDE structure. As a result, the long electrode gap and low voltage effect can be expected in DIDE structure, and a very high luminous efficacy of 7.5 lm/W has been achieved in monochrome green test panel adopting the new cell structure with Ne-Xe (12%) mixture at 400 torr.

• Journal of the Korean Society for Precision Engineering
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• v.25 no.9
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• pp.116-125
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• 2008

Inkjet printing technology with a drop-on-demand (DOD) inkget head technology has been recognized as one of versatile and low cost manufacturing tools in the electronics industry. Concerned with control of driving signal, however, general strategy to optimize jetting stability has not been understood well, because of the inherent complex multi-physics nature in inkjet phenomena. Motivated by this, present study investigates the effect of driving waveforms of piezoelectric head on jetting characteristics of DOD inkjet system focused on jetting stability with phase matching of pressure waves in the print head. The results show that velocities and volumes of the ink jetted droplets were linear relations with the driving signal's maximum voltage, while periodic behaviors are observed with the driving signal's pulse widths.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.1444-1449
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• 2007

Inkjet printing technology with a drop-on-demand (DOD) inkjet head technology has been recognized as one of versatile and low cost manufacturing tools in the electronics industry. Concerned with control of driving signal, however, general strategy to optimize jetting stability has not been understood well, because of the inherent complex multi-physics nature in inkjet phenomena. Motivated by this, present study investigates the effect of driving waveforms of piezoelectric head on jetting characteristics of DOD inkjet system focused on jetting stability with phase matching of pressure waves in the print head. The results show that velocities and volumes of the ink jetted droplets were linear relations with the driving signal's maximum voltage, while periodic behaviors are observed with the driving signal's pulse widths.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.851-854
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• 2004

By approaching the counter electrode to the CNT emitter, remarkable reduction of the cathode operating voltage has been accomplished in the under-gate CNT cathode structure. The peak emission current density of 2.5 ms/$cm^2$, which is sufficient for high brightness CNT field emission display, was obtained at the cathode-to-gate voltage of 57 V when the CNT-to-counter electrode gap was 2.2 ${\mu}m$. The gate current was less than 10 % of the anode current. The CNT cathode with low driving voltage can help the cost-effective field emission display implemented.

• Proceedings of the KIEE Conference
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• 1998.07e
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• pp.1644-1646
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• 1998

High-Smokestacks have been the symbol of the thermal power plant. Those cause the thermal power plant to be damaged by lightening for reaching several hundreds meter. In this paper, we investigated the accident of low-voltage source circuit due to grounding potential rise by lightening via high-smokestack in practically driving power plant, described examination into the cause and the impulse analysis. We analysed the transient voltage by EMTP(ElectroMagnetic Transient Program) via modeling the grounding system of power plant. This theoretical results coincided with practical accidental state. Therefore, it was verified that we could apply the grounding system of power plant and substation with the distribution-circuit analysis(EMTP).

• Proceedings of the IEEK Conference
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• summer
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• pp.74-76
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• 2004

A Half-VDD Voltage(VHDD) Generator using PMOS pull-up transistor and NMOS pull-down transistor was newly proposed for low-voltage DRAMs. The driving current was increased and the power-on settling time was reduced in the new circuit. The newly proposed VHDD generator worked successfully at VDD at 1.5V and fabricated using 0.18um CMOS twin-well technology.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.11a
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• pp.129-131
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• 1999

Driving generator of USMs(ultrasonic motors) with low noise, high efficiency was designed and fabricated. It was focused on merits such as size-reduction, thermal resistance, To control revolution speed, input frequency was varied. Output of generator had frequency range of 39.1 ∼ 43.5 MHz and voltage of 120 V. USM with resonant frequency 40.3 kHz exhibited a maximum torque of 2.5 kg $.$ cm and a maximum revolution speed of about 130 rpm.

• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.1395-1397
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• 2005

This paper presents a novel current driving method for the synchronous rectifier(SR) in a flyback topology. The proposed current driven synchronous rectifier features low power loss, good performance and the gate voltage of FET in the synchronous rectifier is easily controlled by resistor ratio. The proposed SR driving method is implemented in a 200W Flyback converter with 400Vdc input and achieved excellent performance at full load.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.860-865
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• 2004

Field emission display(FED) using carbon nanotubes (CNT) as field emitters is expected to large-area panels with high luminance and low power consumption. In order to perform the uniform luminance with low driving voltage, we introduced a new electrode to apply higher electric potential over the CNT cathode in 2003.[1] In the study, we described the luminance uniformity of the panel and the improvement of emission uniformity by increasing the emission-site density. The luminance uniformity of the several ideal dots which were selected over the display area in the panel was 2.8%. [2] The CNT cathode was irradiated by excimer-laser, which was effective to improve emission uniformity and lower driving voltage. A prototype of CNT-FED character display was performed for middle size message displays. The prototype panel had 48 x 480-dots and the resolution was 1-mm. The panel realized high luminance at low power consumption. It will be important characteristics for legible and ubiquitous displays. [3]

• Proceedings of the KIPE Conference
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• 2003.07a
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• pp.317-322
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• 2003

A novel three-level DC/DC converter (TLC)for high power applications operating from high input voltage Is proposed. Its switch voltage stress can be ensured to be only one-half of the Input voltage. Nevertheless, since all input voltage is applied to the transformer primary side, it has good turns ratio. The driving method of each module is same as those of the conventional phase-shifted ZVS full bridge PWM converter (PSFB) and the zero-voltage-switching (ZVS) of the leading leg are achieved exactly in the same manner as that of the PSFB. Moreover, its three-level operation can considerably reduce the current ripple through the output inductor and it has no problems of the DC-link voltage unbalance. Therefore, it features a low voltage stress, high efficiency, low EMI, high power density, and small sized filter. To confirm the operation, validity, and features of the proposed circuit, experimental results from a 200W, 600V/DC-48V/DC prototype are presented.