| 摘要 |
<p>A cathode-ray tube (10) (CRT) has groups (80) of electron emission cells (50) that produce different degrees of luminance on the phosphor-coated CRT screen (12a, 22). The cells (50) replace the conventional CRT cathode and are fabricated on a planar surface (32). Each cell (50) comprises a fixed number of discrete Field emission electron emitters (32, 36, 38), and the groups (80) comprise different numbers of cells (50), typically in binary relation to one another. The cell groups (80) are interconnected via separate drive lines (82); each group is activated by applying voltage to its line (82). Different combinations of groups (80) may be activated to achieve different brightness intensities on the CRT screen (12a, 22). A cathode (30) having fifteen cells arranged in four groups (1, 2, 4 and 8 cells) is capable of producing sixteen shades of gray. <IMAGE></p> |
