• 전자진흥
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• 제15권9호
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• pp.38-46
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• 1995

• 한국진공학회지
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• 제20권6호
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• pp.403-408
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• 2011

MFX tube를 개발하기 위하여, MFX tube 내에서 전계방출음극으로부터 방출된 전자의 궤적을 SIMION 프로그램을 이용하여 전산모사하였다. 전자의 출발위치와 상관없이 emitter에서 방출된 전자빔을 한곳에 집중시킬 수 있는 optimum extractor voltage Ve가 존재한다는 것을 알아내었다. Extractor voltage Ve는 source voltage Vs에 따라 변하지만, 두 전압의 비율(Ve/Vs)는 항상 일정하고, 그 값은 99.4%였다. Source와 extractor에 인가된 전압의 비율(Ve/Vs)이 99.4%일 때, 교차점에서의 빔 직경은 $1.2{\mu}m$였다. MFXG의 초점 크기는 교차점에서의 beam diameter보다 작을 수 없기 때문에, 교차점에서의 beam diameter을 작게 할 수 있는 조건을 찾는 것은 중요하다. 따라서 위의 두 결과는 MFX tube의 개발에 있어서 매우 중요한 결과로 판단된다.

• 소성∙가공
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• 제9권5호
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• pp.533-538
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• 2000

This study has been carried out to develop a CRT die using hot forging. The conventional CRT die made by casting has defects such as void and inclusion. These defects of the cast die make micro-spots on the surface of the CRT which affect the quality of the final product. So, a hot forging process is developed to avoid these defects of CRT die by the model material test and the rigid-plastic FEM. Firstly, model material tests are carried out with plasticine billets in order to investigate the material flow pattern in the die cavity and to get the reasonable initial values for designing the preform in the FE simulation. And then a finite element analysis has been performed to Predict the preform and the forging load of a CRT die. We also suggest an integrated die-set which combines two die-sets into one die-set to save manufacturing time and cost in case of similar die-size.

• 한국광학회지
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• 제10권5호
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• pp.379-385
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• 1999

칼라 CRT(cathode ray tube) 모니터의 화면밝기와 명암대비 레벨에 따른 화질 특성을 연구하였다. 화면밝기와 명암대비 레벨을 변화시키면서 SQRI(square root integrals)를 측정하여 시감효과를 고려한 분해능을 조사하였다. 또한 이들 레벨에서 삼색 채녈의 색도 좌표와 휘도를 측정하여 채널의 색도 좌표 일정, 색재현 영역, 그리고 채널의 독립을 만족하는 흰색의 최대 휘도를 분석하였다. 결과를 바탕으로 최적의 분해능과 색재현 특성을 가지는 화면 밝기와 명암대비 레벨을 제시하였다.

• 소음진동
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• 제6권4호
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• pp.493-497
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• 1996

TVs or computer monitors with speakers often have a phenomenon called microphonic which shows fringe-like dark pattern on their screens. The major source of this phenomenon is vibration of the shadow mask inside of the Cathode RAY Tube(CRT) which is caused by the sound generated from the speakers. Reducing phenomenon microphonic by modifying the structure of the shadow mask frame in CRT has been examined in this study. A 15" for computer monitor were chosen. Using finite element analysis for vibration and impact, shape of the shadow mask frame was found to reduce microphonic phenomeon. Improved 15" monitors showed good results.d results.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2002년도 International Meeting on Information Display
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• pp.868-871
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• 2002

In this paper, we introduce an efficient three-dimensional magnetic field mapping system for a Deflection Yoke (DY) in Cathode-Ray Tube (CRT). A three-axis Hall probe mounted in a small cylindrical bar and three stepping motors placed in a nonmagnetic frame are utilized for the mapping. Prior to the mapping starts, the inner contour of DY is measured by a laser sensor to make a look-up table for inner shape of DY. Three-axis magnetic fields are then digitized by a three-dimensional Hall probe. The results of the mapping can be transformed to various output formats such as multipole harmonics of magnetic fields. Field shape in one, two and three-dimensional spaces can also be displayed. In this paper, we present the features of this mapping device and show some analysis results.

• 한국광학회지
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• 제10권2호
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• pp.138-145
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• 1999

칼라 CTR(cathode ray tube) 모니터의 빔 전류와 화면위치를 변화시키면서 misconvergence, 스폿 크기, 디스플레이 휘도, 색도 좌표를 측정하였다. 일차원 CCD(charge coupled device)를 사용하여 misconvergence를 측정하였으며, 시감효과를 고려하는 SQRI(square-root integrals)를 도입하여 분해능을 나타내었다. 모니터의 miscovergence는 빔 전류에 영향을 받지 않고 화면의 위치에 따라 변하였으며, 화면 주변부에서의 misconvergence는 분해능을 저하시켰다.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제50권8호
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• pp.409-413
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• 2001

In the electron-gun of CRT, the Mo-tip FEA was employed as cold cathode in order to replace the conventional thermal cathode. The Mo-tip FEA was designed and fabricated according to CRT specification and mounted on the electron-gun. It was known that fabricated cold cathode electron-gun showed better performance in terms of maximum emission current and switch-on time when compared with the ones of thermal cathode electron-gun, but some geometrical structures in the inside of electron-gun must be changed to reduce the gate leakage current. Finally, the potential applicability was guaranteed by means of operating the 19 inch-sized LG-color CRT using the fabricated cold cathode electron-gun.

• 한국의학물리학회:학술대회논문집
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• 한국의학물리학회 2002년도 Proceedings
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• pp.418-421
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• 2002

Fundamental study on quasi-monochromatic parallel radiography using a polycapillary plate and a plane-focus x-ray tube is described. The x-ray generator consists of a negative high-voltage power supply, a filament (hot cathode) power supply, and an x-ray tube. The negative high-voltage is applied to the cathode electrode, and the transmission type target (anode) is connected to the ground potential. The maximum voltage and current of the power supply were -100 kV (peak value) and 3.0 mA, respectively. In this experiment, the tube voltage was regulated from 20 to 25 kV, and the tube current was regulated by the filament temperature and ranged from 1.0 to 3.0 mA. The exposure time is controlled in order to obtain optimum film density, and the focal spot diameter was about 10 mm. The polycapillary plate is J5022-21 made by Hamamatsu Photonics Inc., and the outside and effective diameters are 87 and 77 mm, respectively. The thickness and the hole diameter of the polycapillary are 1.0 mm and 25 ${\mu}$m, respectively. The x-rays from the tube are formed into parallel beam by the polycapillary, and the radiogram is taken using an industrial x-ray film of Fuji IX 100 without using a screen. In the measurement of image resolution, we employed three brass spacers of 2, 30, and 60 mm in height. By the test chart, the resolution fell according to increases in the spacer height without using a polycapillary. In contrast, the resolution slightly fell with corresponding increases in the height by the polycapillary. In angiography, fine blood vessels of about 100 ${\mu}$m are clearly visible.

• 한국의학물리학회:학술대회논문집
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• 한국의학물리학회 2002년도 Proceedings
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• pp.400-403
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• 2002

The fundamental experiments for measuring soft x-ray characteristics from the vacuum capillary are described. These experiments were primarily performed in order to generate line spectra such as x-ray lasers. The generator consists of a high-voltage power supply, a polarity-inversion ignitron pulse generator, a turbo-molecular pump, and a radiation tube with a capillary. A high-voltage condenser of 200 nF in the pulse generator is charged up to 20 kV by the power supply, and the electric charges in the condenser are discharged to the capillary in the tube after closing the ignitron. During the discharge, weakly ionized plasma forms on the inner and outer sides of a capillary. In the present work, the pump evacuates air from the tube with a pressure of about 1 mPa, and a demountable capillary was developed in order to measure x-ray spectra according to changes in the capillary length. In this capillary, the anode (target) and cathode elements can be changed corresponding to the objectives. The capillary diameter is 2.0 mm, and the length is adjusted from 1 to 50 mm. When a capillary with aluminum anode and cathode electrodes was employed, both the cathode voltage and the discharge current almost displayed damped oscillations. The peak values of the voltage and current increased when the charging voltage was increased, and their maximum values were -10.8 kV and 4.7 kA, respectively. The x-ray durations observed by a 1.6 ${\mu}$m aluminum filter were less than 30 ${\mu}$s, and we detected the aluminum characteristic x-ray intensity using a 6.8 ${\mu}$m aluminum filter. In the spectrum measurement, two sets of aluminum and titanium electrodes were employed, and we observed multi-line spectra. The line photon energies seldom varied according to changes in the condenser charging voltage and to changes in the electrode element. In the case where the titanium electrode was employed, the line number decreased with corresponding decreases in the capillary length. Compared with incoherent visible light, these rays from the capillary were diffracted and diffused greatly after passing through two slits.