![]() The neck is often made sufficiently narrow to allow positioning of deflection and focusing components outside it. The electron gun is mounted within the neck portion of the envelope and is connected to the leads coming through the stem. The small opening is terminated by the stem, a disk of glass through which pass metal leads that apply voltages to the several elements of the electron gun. The envelope is usually made of glass, although ceramic envelopes and metal envelopes have been used. The three elements of the basic cathode-ray tube are the envelope, the electron gun, and the phosphor screen (see illustration). This trend is expected to continue until, except for perhaps a few specialized applications, the cathode-ray tube will be primarily of historical interest. Even so, the cathode-ray tube is being supplanted in many of its traditional uses by flat-panel electronic devices. These tubes were commonplace in television sets, computers, homes, hospitals, banks, and airplanes. Hundreds of millions of cathode-ray tubes were in service at the end of the twentieth century, and tens of thousands more were manufactured daily. The character of this pattern is related to, and controlled by, one or more electrical signals applied to the cathode-ray tube as input information. In common usage, the term cathode-ray tube (CRT) is usually reserved for devices in which the display surface is cathodoluminescent under electron bombardment, and the output information is presented in the form of a pattern of light. Cathode-ray tubeĪn electron tube in which a beam of electrons can be focused to a small cross section and varied in position and intensity on a display surface. ![]() McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
0 Comments
Leave a Reply. |
Details
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |