Electron gun assembly for a color cathode ray tube

Abstract

The present invention discloses an electron gun assembly for color cathode ray tube capable of preventing a moiré phenomenon and improving the resolution. As a construction for realizing the electron gun assembly of the present invention, the electron gun assembly comprises a series of orderly arranged electrodes including a control electrode, an accelerating electrode, the third grid electrode and the fourth, plate-shaped grid electrode having a predetermined thickness in order to form, focus and accelerate the electron beams by inducing electrons emitted from cathodes constituting a triode portion to pass electron beam passing apertures, said accelerating electrode is provided with a recess which has a both-side peripheral portion width B in its horizontal direction elongated, compared to its vertical direction width W with respect to the electron beam passing aperture having a predetermined diameter A and which has a predetermined depth D in the third grid electrode direction, and a shape of the accelerating electrode and the fourth grid electrode satisfies the following equation: 2.8 mm≦D/W+T/A≦3.2 mm Therefore, in accordance with the present invention, the relationship between the recess depth of the accelerating electrode and its vertical direction width as well as ratio between the diameter of the electron beam passing aperture and the thickness of the fourth grid electrode can be formed to be positioned within a required range, thereby preventing a deterioration in accordance with the focus characteristics of the electron beam and a moiré phenomenon on the overall region of the screen and thus realizing a high quality image.

Dependencies are inferred from the claim text.