Patent ID: 7919914

Claim:
A discharge lamp, comprising: an electrode at each of two opposed ends of a glass tube in which a gas containing a light-emitting material is enclosed and to an interior of which fluorescent substance is coated, wherein the electrode is provided with an electron emission member containing an electron emission material in a cup having such a shape that a bottom is provided therein, one end thereof is open and an inner cylindrical surface extends from the bottom to the open end; wherein the electrode is provided with a ring-shaped collision-preventing member at the open end of the cup, said collision-preventing member having a sleeve portion and a flange portion, said sleeve portion having an outer diameter by which the sleeve portion is fitted to an opening of the cup and being fixed to the cup, and said flange portion having an outer diameter by which the flange portion covers the entire open end of the cup and covering the forward open end of the cup; wherein the electron emission member is fixedly connected inside the cup adjacent to yet spaced-apart from the bottom of the cup; wherein the electron emission member is cylindrically-shaped and has a first flat, disk-shaped surface, an opposing second flat, disk-shaped surface and a cylindrical surface interconnecting the first and second flat, disk-shaped surfaces with the cylindrical surface disposed apart from and facially opposing the inner cylindrical surface of the cup, the first flat, disk-shaped surface being fixedly connected inside the cup and the second, flat, disk-shaped surface facing the open end; wherein the electrode includes a cap having a centrally-disposed base portion and a connecting portion integrally connected to and surrounding the base portion; and wherein the first flat, disk shaped surface of the electron emission member is connected to the base portion of the cap and is connected interiorly of the cup with the connecting portion of the cap being in contact with the bottom and a portion of the inner cylindrical surface of the cup adjacent the bottom.