ELECTRON EMITTER, CHARGER AND CHARGING METHOD

摘要

An electron emitter emitting electrons continuously and stably for a long time even in the atmosphere, a charger employing the electron emitter, and a charging method employing the charger. The electron emitter (10) comprises an electron emitting element (11) consisting of a first electrode (6), a second electrode (2) and a semiconductor layer (4) formed there between, and a power supply (20) for applying the first electrode (6) alternately with a positive voltage permitting emission of electrons and a negative voltage having a reverse polarity. A porous semiconductor layer (5) is employed at least partially on the surface of the semiconductor layer (4) on the first electrode (6) side. Electrons captured by the porous semiconductor layer (5) during electron emission process being applied with a positive voltage disturb emission of electrons from the electron emitting element (11), but these electrons are removed by applying a negative voltage.