Rectangular color tube with funnel section changing from rectangular to circular

Claim 1

A color receiving tube having a maximum deflection angle greater than 90*, comprising: a face plate section for producing a rectangular shaped image; a phosphorescent surface provided on the inner surface of said face plate section and including a plurality of electron sensitive phosphors arranged in a regular pattern; a funnel section having a wider peripheral portion sealed to the periphery of said face plate section, and a deflection portion whose cross-sectional configuration gradually varies from a rectangular shape substantially similar to that of the rectangular image produced on said face plate section to a circular shape both internally and externally; a circular cylindrical neck portion connected to said circular shaped end opening of said deflection portion; an electron gun assembly including three electron gun units disposed in-line in said neck portion, said electron gun units being equally spaced apart in the horizontal scanning direction of electron beams; and a shadow mask disposed close to said phosphorescent surface, said shadow mask having a plurality of substantially rectangular slits which are arranged in vertical rows, the longer side of said rectangular slits being vertically oriented with corresponding slits in respective rows being gradually shifted vertically to prevent generation of Moire fringes, said inner surface of said face plate section and said shadow mask being substantially similarly curved.