| 摘要 |
<p>PROBLEM TO BE SOLVED: To realize stable electron discharging from a cathode and maintain highly stable discharging for a long service life with a high-brightness cathode for discharge lamps, the cathode being formed of electron emission part sintered substance to be an impregnated type electrode impregnated with easily electron-emitting substance.SOLUTION: In a cathode for discharge lamps that comprises an electron emission part sintered substance having a pointed head at one end and high-melting point mother metal, the electron emission part sintered substance is a porous impregnated cathode formed by impregnating the high-melting point mother metal with easily electron-emitting substance, and the other end, opposite the one end, is embedded in or welded to the high-melting point mother metal. The tip of the pointed head has a tip solid angle closely resembling a conic solid angle. The porous substance is exposed from the surface in a range of 1 mm from the tip of the pointed head, and in other parts the porous substance is blocked.</p> |
