Patent ID: 7902735

Claim:
A gas discharge tube, comprising: an elongated tube within which an electron-emissive film is formed, the elongated tube being filled with a discharge gas and sealed and having an outer wall at one or both of longitudinally opposite ends thereof; a plurality of pairs of display electrodes disposed on a display side of the elongated tube; a signal electrode disposed on a rear side of the elongated tube; and an elongated support member inserted into the elongated tube, the support member extending in the length direction of the elongated tube; the support member having a curved shape so that a curved inner surface thereof forms a discharge space, having longitudinally extending opposite edges, and having an end wall, which is different from the one or both outer walls of the elongated tube, at one or each of longitudinally opposite ends of the support member, the one or each end walls and the curved inner surface forming an elongated depression in the support member, the support member further having a phosphor layer formed on the curved inner surface and on an inner surface of the one or both end walls.