DISPLAY TUBE FOR LIGHT SOURCE

PURPOSE:To simplify an electrode structure of an anode without degrading electric properties by providing a ring anode, a cylindrical anode, and a getter; wherein the ring anode is prepared by forming a metal wire into a circular shape at least a part of which forms a straight line part and forming a gap in the straight line part and fixed at the tip part of an anode lead; the cylindrical anode is so placed as to contact with the inner face of a glass bulb structure fixed in the outside; and the getter is put in the straight line part. CONSTITUTION:A ring anode 11 consists of a circular part 11c having straight line parts 11a, 11b at the positions on opposite to each other in a circularly curved metal wire. One of leads which forms the gap part 11d in the straight line part 11a is bent 11e in a cathode electrode structure 24 almost in parallel to an anode lead 28 and the other straight line part 11b is fixed by welding with the anode lead 28. A cylindrical anode 12 is put and fixed at the tip part of the anode lead 28 in the outer circumferential face of the anode 11. A getter 13 is installed and fixed on a supporting plate 13a in the bent part 11e.