| 摘要 |
<p>PURPOSE:To obtain a structure which is strong against a shock, etc., and holds a cathode position properly, by providing a slit to the reverse surface opposite to the side provided with an insulating substrate holding the cathode and by fitting a set-in piece for fixing the slit to bead glass. CONSTITUTION:On the reverse surface opposite to the side provided with the cathodes of insulating substrate 1 holding commonly a plural number of cathodes at a fixed interval, slit 25 in which set-in piece 11 for fixing substrate 1 to bead glass is provided between through hole 22 in which supports 2 and 3 suppoting filaments are implanted and support notch part 24. In order to prevent insulating substrate 1 from curving and deforming, it is also recommended to form shallow groove 26 nearly in a X shape in the middle point between cathodes on the surface opposite to the surface provided with slit 25.</p> |
