| 摘要 |
PURPOSE: To weaken the magnetomotive force necessary for demagnetization, to reduce the size of a demagnetization device, and also to reduce the electric power consumed by demagnetization by providing a demagnetization coil on a surface crossing the color selection electrode surface of a color CRT(cathode ray tube) and supplying an attenuating AC current. CONSTITUTION: A rectangular ring-shaped demagnetization coil 4 is provided on a surface that crosses at a cross angleθto the surface of the front edge part of a color CRT 1 where a color selection electrode (an aperture grille, etc.) 12 is prepared. Then an AC current which gradually attenuates for demagnetization is supplied to the coil 4 from a demagnetization power supply 5. As the coil 4 crosses the electrode 12, the magnetomotive force necessary for demagnetization has dependency against the angleθ. Therefore, the magnetomotive force necessary for demagnetization can be reduced by the proper selection of the angleθ. It is desirable to set the cross angle in a range of 2 to 40 deg. between the surface of the electrode 12 and the surface including the coil 4.
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