Patent ID: 7312565

Claim:
A color cathode ray tube apparatus comprising: a color cathode ray tube comprising an electron gun for emitting three electron beams that are aligned in a horizontal direction, and a phosphor screen that emits light when struck by the three electron beams emitted from the electron gun; and a deflection device comprising a horizontal deflection coil that generates a horizontal deflection magnetic field for deflecting the three electron beams in the horizontal direction, and a vertical deflection coil that generates a vertical deflection magnetic field for deflecting the three electron beams in a vertical direction; wherein the deflection device further comprises a pair of first permanent magnets that are arranged on a vertical axis symmetrically with respect to a tube axis so that the three electron beams are converged in the horizontal direction near the tube axis and a pair of second permanent magnets that are arranged on a horizontal axis symmetrically with respect to the tube axis so that the three electron beams are diverged in the horizontal direction near the tube axis, K TBH /K EWH <10 is satisfied in at least one location within a range of 3 to 13 mm on a side of the phosphor screen with respect to a reference line in a tube axis direction, where K TBH (Gauss/cm) is an inclination coefficient of a distribution curve near the tube axis on the horizontal axis of a vertical direction magnetic flux density of a magnetic field formed by the pair of first permanent magnets and K EWH (Gauss/cm) is an inclination coefficient of the distribution curve near the tube axis on the horizontal axis of a vertical direction magnetic flux density of a magnetic field formed by the pair of second permanent magnets, and K H >1.5 and K V >1.5 are satisfied in at least one location within the range of 3 to 13 mm on the side of the phosphor screen with respect to the reference line in the tube axis direction, where K H (Gauss/cm) is an inclination coefficient of a distribution curve near the tube axis on the horizontal axis of a vertical direction magnetic flux density of a combination magnetic field formed by the pair of first permanent magnets and the pair of second permanent magnets and K V (Gauss/cm) is an inclination coefficient of a distribution curve near the tube axis on the vertical axis of a horizontal direction magnetic flux density of the combination magnetic field.