Patent ID: 6492766
Filing Date: 2002-12-10
Classification: H01J

Abstract:
A color cathode ray tube, including a vacuum envelope, which is comprised of a panel portion on which a phosphor screen formed of at least phosphors in three colors is coated and adjacent to which a shadow mask is disposed, a neck portion which accommodates an electron gun which is comprised of an electron beam generating portion which generates three electron beams arranged in the horizontal direction and a main lens portion which focuses and converges said three electron beams onto said phosphor screen, and a funnel portion which connects said panel portion and said neck portion and on which a deflection yoke is mounted for scanning three electron beams emitted from said electron gun on said phosphor screen, wherein:said main lens portion is comprised of an anode electrode to which an anode voltage is applied and a focusing electrode to which a focusing voltage which is lower than said anode voltage is applied, the color cathode ray tube has the relationship that the ratio between the diagonal size De of said phosphor screen and the distance Lg from the center of said phosphor screen to an end portion of said focusing electrode which faces said anode electrode in an opposed manner is set to De/Lg>1.5, and said focusing electrode and said anode electrode are constituted such that said focusing electrode and said anode electrode have single opening portions whose opening size in the horizontal direction is not less than 68% of the outer diameter of said neck portion and end surfaces of said opening portions face each other in an opposed manner in the tube axis direction along which said electron beams pass.