Color selection electrode, method of producing color selection electrode and cathode ray tube.

Abstract

A color selection electrode and a method of producing the same, for a high definition cathode ray tube with a finer pitch of mask apertures free from limitations due to the thickness of the iron-alloy plate of the mask. The method comprising, the steps of depositing a first resist on both a surface of an iron-alloy plate comprised of a low carbon steel plate, a surface being directed to an electron gun (small diameter side) and another surface being directed to a phosphor screen (large diameter side) and patterning the resist by photolithography; forming an electrodeposited metal layer on portions of the electron gun side of the iron-alloy plate where the first resist is not formed; depositing a second resist on the entire surface of the iron-alloy plate which is directed to the electron gun side to cover the first resist and the electrodeposited metal layer; using the first resist as a mask and etching the surface of the iron-alloy plate which is directed to the phosphor screen side; and removing the first resist and the second resist.

Dependencies are inferred from the claim text.