• Title/Summary/Keyword: Electron Gun Heater

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Low Power Design on Heater and Cathode of Electron Gun for High Resolution CRT (고해상도 CRT용 전자총의 히터 및 캐소드 저전력 설계)

  • Kim Hack-Sung
    • The Transactions of the Korean Institute of Power Electronics
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    • v.10 no.6
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    • pp.618-625
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    • 2005
  • This paper has achieved that an optimal design and experiments of heater and cathode of electron gun that serve to embody high current density in CRT display. For the high brightness, high resolution and larger size in CRT display, high current density of electron gun is indispensible. An Impregnation style cathode is used, and must heighten operating temperature of heater to get high current density for this, it is proportional hereupon and power dissipation increases. In this paper, to get low power cathode with high current density, There are produced and tested sample that differ lead type of heater, coating method, the pitch and number of winding of the first and second coiling in the heat emission area for the low power design of high current density cathode heater in this paper.

전자총 히터(electron gun heater) 자동검사를 위한 머신비젼 알고리즘

  • 김인수;이문규
    • Journal of the Korean Society for Precision Engineering
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    • v.17 no.3
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    • pp.58-67
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    • 2000
  • Electron gun heaters are used to heat a cathode in video(TV) monitors. Major defects of the electron gun heaters include dimensional inaccuracy and pollution with dirty materials. In this paper, to save the labor and time being taken to inspect the heaters, a machine vision system is considered. For the system, a new algorithm is developed to measure the 9 different dimensions of each heater and to detect polluted defects. The algorithm consists of three stages. In the first stage, the center of the heater image is obtained and then its boundary detection is performed. For the efficient boundary detection, a mask called the sum mask is used. In the second stage of the algorithm, a set of fiducial points are determined on the boundary image. Finally, using the fiducial points specified dimensions are measured and the amount of polluted area is computed in the third stage. The performance of the algorithm is evaluated for a set of real specimens. The results indicate that measurements obtained by the algorithm satisfy the tolerance limits fur most of the dimensions and the algorithm detects the polluted defects successfully.

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Measurement of Energy Parameters for Electron Gun Heater Currents and Output Dose Rate for Electron Beams from a Prototype Linac (연구용 선형가속기의 전자총 가열 전류에 따른 전자선의 에너지 인자 측정과 출력 측정 연구)

  • Lim, Heuijin;Lee, Manwoo;Kim, Me Young;Yi, Jungyu;Lee, Mujin;Kang, Sang Ku;Rhee, Dong Joo;Jeong, Dong Hyeok
    • Progress in Medical Physics
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    • v.27 no.1
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    • pp.25-30
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    • 2016
  • The dosimetric characteristics were experimentally evaluated for electron beams from the prototype linac developed for radiotherapy units. This paper focuses on the electron beam output and energy variations as a function of electron gun heater current. The electron energy was derived from its mean and most probable energies measured by film dosimetry. The electron beam output at the maximum electron energy was measured with the plane parallel ionization chamber in water using TRS-398 dosimetry protocol. The mean energy and the most probable energy of the electron beam were 6.54~3.31 MeV and 5.94~2.80 MeV at electron gun current of 2.02~2.50 A respectively. The output dose rate for an electron beam of mean energy 6.54 MeV was 5.41 Gy/min ${\pm}1.5%$ at the reference depth in water.