| 摘要 |
<p>PURPOSE:To eliminate temperature disunion of linear cathode electrodes for stably obtaining a picture having no variety in brightness by arranging a prescribed porous layer at a contact part of a supporting means with a linear cathode electrode. CONSTITUTION:A substrate 3a provided with the hole parts on a metal plate is formed on a cathode supporting means 3 followed by forming a porous layer 3b of a heat-resisting insulating material on the surface of the substrate 3a. Then, when a linear cathode electrode 5 is conducted, the electrode 5 emits electrons. When a control electrode 2 is put on the lower potential than the electrode 5, emitted electrons 7 are attracted by a takeoff electrode 6. When the electrode 6 is put on the higher potential than the electrode 5, the electrons 7 are accelerated to form an electron beam. In this series of operations, a temperature drop is not generated at the contact part, when the electrode 5 is heated up to a high temperature by a heater current. Accordingly, the electrode 5 generates no temperature disunion or the like.</p> |
