Patent ID: 6972515

Claim:
A flat type color cathode ray rube including a rectangular panel having a substantially flat outer surface and an inner surface having a certain radius of curvature, a funnel installed to a rear of the panel, a fluorescent surface coated onto an internal surface of the panel and performing a certain fluorescence function, an electron gun discharging electron beams radiating the fluorescent surface, a shadow mask for making the electron beams from the electron gun land on a certain portion of the fluorescent surface, a frame for fixing/supporting the shadow mask, a spring and a stud pin for combining the frame assembly with the panel, an inner shield combined with the certain side of the frame from the panel side to the funnel side in order to protect the cathode ray tube against a terrestrial magnetism, an electron gun placed inside a neck portion of the funnel and generating the electron beams, a deflection yoke installed to the outer surface of the neck portion of the funnel in order to deflect the electron beams from the electron gun in a certain direction, a CPM (convergence & purity magnet) for precisely adjusting the deflected direction of the electron beams and a reinforcing band installed to the outer circumference of the portion at which the panel and the funnel are combined in order to protect the panel and the funnel against an air pressure and external impacts, wherein the flat type color cathode ray tube satisfies the following equations: 1.2≦ Ph H /Ph C ≦1.6, 0.9≦ Ph V /Ph C <1.0 or 1.0< Ph V /Ph C ≦1.1, 1.2≦ Ph D /Ph C ≦1.6 where a central portion glass transmissivity of the panel is about 45%˜75%, a radius of curvature in the diagonal direction (Rp D ) of the panel has a range of 3.5 R≦Rp D ≦8.0 R (R is calculated by multiplying 1.767 by an effective surface diagonal axis length of the panel), Ph C is a horizontal pitch of an electron beam passage hole at the central portion of the shadow mask, Ph H is a horizontal pitch of the outmost electron beam passage hole in the long axis direction of the shadow mask, Ph V is a horizontal pitch of the outmost electron beam passage hole in the short axis direction of the shadow mask, and Ph D is a horizontal pitch of the outmost electron beam passage hole in the diagonal axis direction of the shadow mask.