| 摘要 |
PURPOSE: A longitudinal scan type color CRT(Cathode Ray Tube) is provided to be capable of improving the purity characteristic of the CRT by increasing the rate of horizontal pitch change of a shadow mask slot. CONSTITUTION: A color CRT comprises an electron gun having three cathodes for generating electron beams of red, green, and blue, a screen, a plurality of shadow masks spaced apart from each other for discriminating colors, and a deflection apparatus having a pin cushion shaped deflection field generating part for deflecting the electron beam emitted from the electron gun to the short axis direction of the screen and a barrel shaped deflection field generating part for deflecting the electron beam to the long axis direction of the screen. When expressing the first horizontal pitch between slots located at the center portion of the shadow mask as 'Pho', the second horizontal pitch between slots located at the end portion of the diagonal axis of the shadow mask as 'Phc', and the third horizontal pitch between slots located at the end portion of the horizontal axis of the shadow mask as 'Phx', the equations of 'Pho< Phc< Phx' and '0.2<= Pho< 0.35' are simultaneously satisfied.
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