CATHODE FOR ELECTRONIC TUBE

摘要

There were problems with the conventional cathode for electronic tubes such as: metals that composing the substrate were subjected to heat deformation resulting in a relatively large drift of cutoff voltage. It is the object of the present invention to solve this problem by diminishing the heat deformation of the substrate to obtain a cathode with a small drift of cutoff voltage. Heat expansion coefficients can be made uniform while metals in the metal layer are prevented from diffusing into the substrate by incorporating the same metals as in the metal layer on the substrate into the metals composing the substrate, thereby suppressing deformation of the substrate. <IMAGE>