摘要 |
<p>A display device with a DAF-gun (Dynamic Astigmatism and Focusing) in which the first focusing electrode (G3a) has at the side facing the pre-focusing part of the electron gun three elongated apertures (36, 37, 38). Hereby in operation in the vicinity of the elongated apertures an electron-optical field is generated between the pre-focusing part of the electron gun and the elongated apertures for reduction of the vertical dimension (vertical meaning transverse to the plane of the electron beams) of the beam size of the electron beams in the main lens. This reduction of the electron beam size results in an increase of the vertical dimension of the beam spot on the screen. This reduces Moiré effects.</p> |