| 摘要 |
<p>A cathode ray tube (10, 110, 110', 210, 310) includes an electron gun (12, 212) directing electrons away from a faceplate (20, 220, 320) having an electrode (22, 222, 322) biased at screen potential. One or more electromagnets (144, 146, 148) located on or near the rear wall (41, 41') of the tube envelope (40, 40', 40') are biased with dc currents so that the electron beam (30, 30', 30', 330) is deflected by the magnetic field produced thereby to impinge upon the faceplate (20, 220, 320). The electron beam (30, 30', 30', 330) is magnetically deflected over a relatively small angle as it exits the electron gun (12, 212) to scan across the faceplate (20, 220, 320) to impinge upon phosphors (23, 223, 323) thereon to produce light depicting an image or information. The electromagnet (144) closest the electron gun (12, 212) is typically biased to produce a strong magnetic field to deflect electrons to the faceplate (20, 220, 320) near to the electron gun (12, 212). The electromagnets (146, 148) more distant the electron gun (12, 212) produce magnetic fields to direct electrons towards the faceplate (20, 220, 320), with the electromagnet (148) most distant the electron gun (12, 212) deflecting the electrons to tend to increase the landing angle thereof on the faceplate (20, 220, 320). One or more of the foregoing electromagnets (144, 146, 148) may be utilized in cooperation with one or more electrodes (44, 46, 48, 246, 248, 346) biased at a potential to similarly deflect the electrons to the faceplate (20, 220, 320).</p> |
