| 摘要 |
PURPOSE:To prevent deterioraton of convergence characteristic, facilitate manufacture and improve parts accuracy by inclining the flat portion of the second grid in the vicinity of electron beam passing holes in both sides thereof, in such a direction that the electron beams in both sides come close to the central electron beam. CONSTITUTION:Since the flat portions 13R, 13B in both sides of the second grid electrode 10 are inclined so that they are facing inside each other, the electron beams 14R, 14B in both sides having passed the first grid electrode 2 are deflected by asymmetrical electric field so that these come close to the central electron beam 14G and then enter the main lens consisting of the third grid electrode 4 and fourth grid electrode 5. Since fluctuation due to voltage difference generated by focusing of asymmetrical electric field curves in both sides of main lens consisting of the third and fourth grid electrodes 4, 5 becomes smaller as is becoming far from the gun axes 6R, 6B, the electron beams 14R, 14B entering through the area near the central gun axis 6G from the third grid electrode 4 do not show any deterioration of static convegence charactristic. |
