Patent ID: 7317285
Filing Date: 2008-01-08
Classification: G03G

Abstract:
1. A method for cleaning fine particles from an electron emission device comprising: an electron emitter including a lower electrode, an upper electrode made of a thin film, and a semiconductor layer formed between the lower electrode and the upper electrode, a surface of the upper electrode being exposed to an external space; a counter electrode disposed opposite the upper electrode across the external space; first voltage control means for selectively applying between the lower and upper electrodes (i) an electron emitting voltage having a polarity for accelerating electrons in the semiconductor layer such that the accelerated electrons are passed through the upper electrode and emitted to the external space, (ii) a predetermined voltage for charging fine particles adhered to the surface of the upper electrode, (ii) a voltage of opposite polarity to the polarity of the electron emitting voltage, or (iv) no voltage; and second voltage control means for selectively applying at least one voltage between the upper electrode and the counter electrode having a predetermined relationship to the voltage applied between the lower and upper electrodes by the first voltage control means; said method comprising the steps of: