Electron generating device, image display apparatus, driving circuit therefor, and driving method

Abstract

In order to prevent voltage drops across the wiring resistances in a multi-electron source having a plurality of electron emitters wired in the form of a matrix through a plurality of data wiring layers and a plurality of scanning wiring layers, a constant current signal is output to each data wiring layer. At this time, each non-selected data wiring layer tends to be set at a high impedance and vary in potential, resulting in an abnormal turn-on operation or an electron orbit shift. A driving circuit for solving this problem is provided. A switch for switching a constant current output unit for outputting a constant current regardless of the impedance of a signal output destination, and a constant voltage output unit for outputting a constant voltage regardless of the impedance of a signal output destination is connected to each data wiring layer. For example, a constant-current circuit (,) as a current output unit always outputs the same current (I,to In) to a switch (,). A pulse width signal (PW,to PWn) from a pulse-width modulation circuit (,) serves to switch the mode of outputting a current (I,to In) to a data wiring layer (D,to D,) and the mode of fixing a data wiring layer to voltage GND.