| 摘要 |
PURPOSE: Vacuum fluorescent display is provided to prevent X-ray leakage and overheat of the phosphor layer with a simple structure. CONSTITUTION: A vacuum fluorescent display comprises a cathode electrode(4) for emitting electrons, a grid electrode(5) for extracting the electrons from the cathode electrode, an anode electrode(6) for accelerating the electrons extracted from the cathode electrode, at least one envelope(1) which accommodates the cathode electrode, the grid electrode, and the anode electrode in a vacuum space and has a display portion having light transmission properties, a phosphor layer(2) formed on an inner surface of the display portion of the envelope and adapted to emit light upon bombardment of the electrons accelerated by the anode electrode, and a cap made of an X-ray shielding material and supported outside the envelope so as to surround the display portion of the envelope through a gap, the cap having a light exit surface from which the light emitted from the phosphor layer emerges through the display portion of the envelope.
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