Patent ID: 7105996

Claim:
An electron gun for a color CRT, comprising: a triode unit for generating three electron beams and controlling and accelerating the generated electron beams; a main focusing lens unit that focuses the electron beams generated by the triode unit; a first electrostatic screen grid installed in the main focusing lens unit having three electron beam through holes linearly-arranged for passing the three electron beams and two of the holes are external holes, and the first grid having a first oval shaped hole that passes all three electron beams, the first oval shaped hole spaced a distance d 1 from the through holes; and a second electrostatic screen grid installed in the main focusing lens unit having three electron beam through holes linearly-arranged for passing the three electron beams and two of the holes are external holes, and the second grid having a second oval shaped hole that passes all three electron beams, the second oval shaped hole spaced a distance d 2 from the through holes; wherein the first grid external holes have an external distance HL 1 and an internal distance HR 1 and the second grid external holes have an external distance HL 2 and an internal distance HR 2 ; and wherein HL 1 is greater than HR 1 , HL 2 is greater than HR 2 , d 1 is greater than d 2 , HL 2 is greater than HL 1 , and HL 2 +HR 2 is greater than HL 1 +HR 1 .