| 摘要 |
<p>The invention relates to electronic tubes, and particularly to beam-indexing display tubes. According to the invention, the screen (14) of the tube consists of a cathodoluminescent single-crystal envelope, for example an aluminium yttrium oxide crystal doped with cerium. The screen is covered with luminophore bands of alternating colours. At regular intervals, indexing bands (I) are left free and covered by neither luminophores (16) nor opaque separation bands (17). When the electronic beam hits these bands, an indexing light signal (ultraviolet or other) is emitted. This light is trapped in the crystal and exits via the wafer where a sensor (22) picks it up and provides the electrical indexing signal. It is therefore possible to create screens of particularly small dimensions without any deterioration in resolution.</p> |
