| 摘要 |
PURPOSE:To prevent electrostatic charges on a fluorescent screen made of insulative ceramic by forming a conductive layer on the surface of fluorescent screen, and connecting to a holder of metal in electrical terms. CONSTITUTION:A conductive layer 2 is provided on the incident surface of a ceramic fluorescent screen 1 and connected with a holder 3 of metal electrically, so that irradiation of a charged particle beam 5 onto the fluorescent screen 1 to cause giving electric charges will result in discharging to the holder 3 through the conductive layer 2. Therefore, accumulation of electric charges is prevented, and the fluorescent screen 1 is precluded from impairing of its function. Further the inbound charged particle beam 5 generates secondary electrons within the conductive layer 2. These secondary electrons also irradiate on the fluorescent screen 1 to generate emission of fluorescence. This allows achievement of high brightness.
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