Matrix-Driven Electron Source for MDS Flat-Panel CRT

Abstract

A matrix-driven electron source essential for a large high-definition MDS flat-panel CRT has been developed. This electron source consists of twe parts, triode with a vertically extended line cathode and two grids, and switching electrodes for vertical scanning by an electron beam emitted by the line cathodes. This structure allows a high emission current with a low voltage modulation signal. Driving circuits and the structures of the grids are simplified by a new driving method in which a modulation signal is applied to directly-heated type line cathodes instead of grids. Beam current from each segment of the electron source is made uniform by a newly-developed correction circuit which equalizes the cut-off voltages of each segment.