| 摘要 |
An electron gun of the in line type comprises cathodes ( 2 ) for emitting electrons, the cathodes being juxtaposed in a first direction. The electron gun comprises a main lens section ( 4 ) for focusing the beams of electrons onto a display screen ( 36 ). Conventionally, the electrodes ( 20, 21, 22 ) of the main lens section comprise a base plate ( 23 ), which is a plate shaped element provided with separate apertures for each of the beams. According to the invention, at least one of the electrodes ( 10, 11, 12 ) of the main lens section is provided with a so called field cutter ( 14, 19 ), which is a plate shaped element provided with a common aperture for all beams. The field cutter allows in preferred embodiments to have astigmatic main lenses that result in better spot performance and a reduced horizontal magnification. Preferably, the main lens has positive dynamic astigmatism, so that a separate DAF section is no longer required.
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