• Journal of the Korean Graphic Arts Communication Society
• /
• v.9 no.1
• /
• pp.1-11
• /
• 1991

In this reseach, double-layered photoconductor consist of the carrier generation layer(CGL) of $\varepsilon$ type copper phthalocyanine thin film by an aqueous coating method and the carrier transport layer(CGL) of polyvinyl carbazol(PVK) by spin coating. We inverstigated effect of the surfactant solution and cathod electrolysis to the crystal type of $\varepsilon$-CuPc in CGL with TEM, SEM and X- ray diffraction spectroscopy and studied the mechanism of an aqueous coating for the preparation of CGL. The effect of the washing of CGL about the electrophotographic characteristics of the $\varepsilon$-CuPc/PVK doublelayered photoconductors is studied also.

• Proceedings of the Korean Vacuum Society Conference
• /
• 1999.07a
• /
• pp.212-212
• /
• 1999

Ar-O2 분위기의 Plasma 표면 처리된 OPP 의 polymer 위에 약 400$\AA$ 정도로 sputter 코팅된 Al의 부착력에 관하여 연구를 하였다. 금속과 polymer와 같이 성질이 서로 다른 물질이 서로 결합할 때 접착력은 제품의 성능과 신뢰도를 결정하는데 매우 중요한 인자이다. 최근 고분자재료의 표면을 플라즈마 처리 (plasma surface treatment)에 의해 고분자와 금속도포(coating) 층간의 접착력향상에 따라, 증착필름 및 인쇄용 필름 등의 기능도 향상시킬 수 있다. 저온 plasma를 이용한 표면처리는 plastic 재료가 가지고 있는 기본적인 특성을 저해하지 않고, 그 표면 층만을 개량하는 plasma 또는 sputter etching 갚은 electrical discharge 방법은 진공 증착 방식에서 많이 사용되고 있다. 7$\mu\textrm{m}$의 두께 OPP polymer를 10m/min의 속도로 OPP의 표면을 연속 plasma pretreatment를 하였다. 5$\times$10-2torr에서, PEM(Plasma Emission Monitor)를 이용하여 plasma intensity에 따른 Ar/O2비를 변화시키면서 test를 하였다. AFM과 XPS를 이용하여 OPP의 표면분석을 하였다. 이 plasma처리는 기존의 D.C plasma 처리 방식과는 달리 Midium frequency AC voltage hollow cathod 방식으로 plasma를 발생된 high energy plasma 분위기를 만들 수 있다. 이러한 방식은 -cycle일 때 plasma로부터 발생된 전자가 polymer 표면을 bombard 하게 되고, +cycle 일 때 polymer 표면이 cathod 가 되어 active ion에 의해 sputtering 이 된다. 이때 plasma 처리기의 polymer 기판 후면에 magnet를 설치하여 높은 ionization을 발생시켜 처리 효과를 한층 높여 주었다. 이 plasma 처리는 표면 청정화, 표면 etching 이 동시에 행하는 것과 함께 장시간 처리에 의해 표면에서는 미세한 과, C=C기, -C-O-의 극성기의 도입에 의한 표면 개량이 된다는 것을 관찰할 수 있다. OPP polymer 표면을 Ar 100%로 plasma 처리한 경우 C-O, C=O 등의 carbonyl가 발생됨을 알 수 있었다. C-O, C=O 등의 carbynyl polor group이 도입됨에 따라 sputter된 Al의 접착력이 향상됨을 알 수 있으며, TEM 관찰 결과 grain size도 상당히 작아짐을 알 수 있었다.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.14 no.1
• /
• pp.8-14
• /
• 2009

A lamp which is currently employed to LCD(Liquid Crystal Display) Backlight is almost CCFL(Cold Cathod Fluorescent Lamp) and EEFL(External Electrode Fluorescent Lamp). However, the use of these lamps is being restricted as RoHS(the Restriction of the use of certain Hazardous Substances in electrical and electronic equipment) regulation is gradually reinforced. According to this situation, the manufacturing of a lamp which doesn't use mercury is unescapable. Moreover, LCD TV has a defect which take place Motion Blur phenomenon due to response time of LC(Liquid Crystal), and Hold-type characteristic which only exists in LCD differently to CRT, PDP. In this paper, an inverter is proposed to drive a plane light source lamp which is not containing mercury. Driving circuit of proposed inverter is simple because the number of semiconductor device and magnetic device is reduced by using forward topology. Also, Motion Blur phenomenon is decreased by dividing the plane light source lamp to six block along vertical direction, and scanning. Finally, we proved usefulness of proposed inverter through experiment.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2000.11a
• /
• pp.295-298
• /
• 2000

Vanadate glasses in the Li$_2$O-P$_2$O$_{5}$-V$_2$O$_{5}$ system containing 10~20mo1% glass former, P$_2$O$_{5}$ were prepared by melting the batch in pt. crucible followed by quenching on the copper plate. We found that Li$_2$O-P$_2$O$_{5}$-V$_2$O$_{5}$ g1ass-ceramics obtained from crystallization of glass showed significantly higher capacity and longer cycle life than Li$_2$O-P$_2$O$_{5}$-V$_2$O$_{5}$ g1ass. In the present paper, we describe electro-chemical properties during crystallization process and find the best crystallization condition of Li$_2$O-P$_2$O$_{5}$-V$_2$O$_{5}$ g1ass as cathod material. Li$_2$O-P$_2$O$_{5}$-V$_2$O$_{5}$ glass-ceramics shows superior rechargeable capacity of 220 mAh/g in the cycling between 2.0 and 3.9V. between 2.0 and 3.9V.

• Journal of the Semiconductor & Display Technology
• /
• v.6 no.4
• /
• pp.53-57
• /
• 2007

In paper, We evaluated for various diode type ESD protection device using TLP measurement method. An Evaluation diode is divided to Enclosed type and Stripe type as pattern style in extensive. These diodes is split up followed factor that Anode-to-Cathod space, N+ region width, Multi type and Contact to Active space. After a TLP measurement, we can be got the Vt2, It2 by I-V characteristic values. In the results, diode of enclosed type is present relatively higher Current capability(It2) than stripe type in a same voltage conditions. And the Second-breakdown voltage(Vt2) were that Stripe type's diode higher than Enclosed type's diode as have $14{\sim}15V$. Finally we suggest the best diode design condition as ESD protection device using entire consequence.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 1996.04a
• /
• pp.271-274
• /
• 1996

TV나 스피커가 부착되는 PC Monitor에서는 스피커에서 나오는 음향에너지로 인한 진동으로 물결무늬모양의 화면떨림현상이 발생하는데 이를 감소시키기 위해 본 연구에서는 모니터에서의 스피커 부착부분에 대한 개선이 아닌 CRT 자체를 개선하여 어떤 형태의 모니터에 장착하여도 Microphonic현상이 최소화될 수 있는 CRT를 개발하고자 한다. 본 연구에서는 15" CRT를 대상으로 Microphonic현상의 원인규명과 개선안을 도출하였다. Microphonic현상의 주파수분석과 모드분석을 통해 원인을 규명하고 중요부품을 위주로 유한요소해석모델을 구현하였으며 이를 이용하여 중요인자 중 개선이 쉬운 스프링과 프레임에 대한 형상개선을 통해 Microphonic현상수준을 크게 개선하였다. 특히 17" 프레임에 대한 구체적인 개선형상은 실험계획법을 사용하여 도출하였다. 15" GoldStar CRT의 경우는 동일모델에서 최고수준으로 현재 생산 판매되고 있다. 현재 생산 판매되고 있다.

• Journal of the Korean Ceramic Society
• /
• v.35 no.3
• /
• pp.245-250
• /
• 1998

Field emission display (FED) is currently being explored as a potential flat panel display technology. The need of new materials for low voltage blue phosphors for FED focused our attention on the $Y_2O_3-Nb_2O_5$ sys-tem. Yttrium niobate doped with $Bi^{3+}$ was prepared by solid state reaction technique and the optimization of the luminescent properties with a control of $Bi^{3+}$ amounts and Y/Nb ratio was studied. Under 254 nm and low voltage electron excitations $Bi^{3+}-activated$ YNbO4 phosphors showed a strong and relatively narrow blue em-ission band with a range of 420 to 450 nm, Especially 0.4wt% $Bi^{3+}\;doped\;YNbO_4$ phosphors with Y/Nb ratio of 1/1 showed the maximum emission intensity. Under low voltage electron excitation maximum emission in-tensity appeared at the Y/Nb ratio of 0.495/0.505.

• Journal of the Korean Ceramic Society
• /
• v.35 no.3
• /
• pp.273-279
• /
• 1998

Unite cell of soid oxide fuel cell (SOFC) that consists of a dense yttria-stabilized zirconia(YSZ) electrolyte a porous nickel-YSZ cermet anode and a porous strontium- doped lanthanum manganate(LSM) cathod was fabricated from using pore former through co-firing technique. Initial sintering shrinkage rates of each layer were identified for fabricating SOFC. Heterogenous sintering was very effective in tailoring shrinkage rate for three layers. The powder tailoring necessary for shrinkage rate matching are as follows ; electrolyte of 60% TZ8YS/ 40% TZ8Y mixture anode of 51wt% NiO/49 wt% (70wt% TZ8YS/30 wt% UT ZrO2) mixture and cathode of 80% LSM/20% UT ZrO2 mixture . The overall sintering shrinkage rate differences of three layers using these compositions were maintained in a few percent.

• Proceedings of the KIPE Conference
• /
• 2007.11a
• /
• pp.47-49
• /
• 2007

For the magnetron, two kinds of auxiliary power is required to generate proper heat and electromagnetic field. In this paper the development of filament power supply and magnet power supply for high power industrial magnetron is studied. The filament power supply which is generate proper heat, even it doesn't require high power like main power supplies, has many consideration such as high voltage insulation and power control coordinated with high voltage cathod current to maintain constant heat generation. The novel control method using constant resistance control is proposed for accurate control of filament power supply.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.2 no.2
• /
• pp.11-18
• /
• 2001

The design method of high potential generator of diagnostic X-ray apparatus by using inverter is presented. For the high potential generator, a line filter, a rectifier, a Pulse width modulation control, bridge drive, a high potential transformer and a high potential rectifier circuit were adopted. The high potential generator with switching frequency to be 40 KHz is fabricated by using design method presented in this method. The experimental results are as followings; variable volts of 0∼620 V and variable currents 50∼500 mA.