| 摘要 |
PURPOSE:To prevent generation of wrinkles on the mesh electrode surface or a disorder of the collimation lens, etc., by furnishing a step sunken a little more than the thickness of the mesh electrode fixing flange, at the end of the bulb wall where the plate of a glass bulb is to be airtight sealed. CONSTITUTION:The inside of the top surface of a glass bulb 1 is made lower by t2 than the thickness t1 of the flange of a mesh ring 8 (as t2=t1+0.01-0.02mm). And the size T2 in the radius direction of the glass bulb where the thickness is lower by t2 is arranged as T1/T2=1-0.77, where T1 is the thickness of the glass bulb, which is also determined in consideration of allowable installation accuracy gap to the outer diameter phiD of the mesh ring at the flange portion. In order to form a deflecting electrode 3 inside the glass bulb 1 with a step at its tip, a metal such as Ni or Cr is vacuum evaporated, when, the step 1a is vacuum evaporated at the same time, and then, they are separated into the deflecting electrode 3 and the vacuum evaporated electrode 3a around the mesh ring 8, by etching or laser processing. |
