| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an impregnated type cathode structure with high proofing against vibration, capable of saving power consumption. SOLUTION: A cup-like fixed member 23 is installed in the inside of one end part of a cathode sleeve 22 and a porous cathode substrate 24 impregnated with an electron radiating substance is fixed in the cup-like fixed member 23. A heater 25 is installed in the cathode sleeve 22. A shielding cylinder 26 is coaxially installed in the outside of the cathode sleeve 22. A slit part 27 is swelled out, cut, and raised inwardly in an arc-like shape for every 120 deg. in the lower end of the shielding cylinder 26 and welded in the lower end of the cathode sleeve 22. A cylindrical holder 31 is coaxially installed in the outside of the shielding cylinder 26. An end face part 33 having an aperture 32 is formed in the upper face of the cylindrical holder 31 and the shielding cylinder 26 is inserted into the aperture 32. The upper part of the shielding cylinder 26 is welded with and fixed in the end face part 33 of the cylindrical holder 31 by supporting members 34 having an L-shape cross section.</p> |
