ELECTRON EMITTING DEVICE

Abstract

The electron emitting device 10 includes a substrate 11, a lower electrode 12, an emitter section 13, an upper electrode 14. The upper electrode disposed above the emitter section to oppose the lower electrode so as to sandwich the emitter section with the lower electrode. The upper electrode has a plurality of micro through holes. The upper electrode is configured in such a manner that distance t1 (gap distance t1) between the lower surface of the upper electrode in the vicinity of the micro through holes 14c and the upper surface of the emitter section is substantially constant for any of the micro through holes.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

Various other objects, features and many of the attendant advantages of the present invention will be readily appreciated as the same becomes better understood by reference to the following detailed description of the preferred embodiments when considered in connection with the accompanying drawings, in which:

FIG. 1 is a partial cross-sectional view of an electron emitting device according to a first embodiment of the present invention;

FIG. 2 is a partial plan view of the electron emitting device shown in FIG. 1;

FIG. 3 is a partial cross-sectional view of the electron emitting device shown in FIG. 1 under manufacturing process;

FIG. 4 is a partial cross-sectional view of the electron emitting device shown in FIG. 1 under manufacturing process;

FIG. 5 is a partial cross-sectional view of the electron emitting device shown in FIG. 1 under manufacturing process;

FIG. 6 is a partial cross-sectional view of the electron emitting device shown in FIG. 1 under manufacturing process;

FIG. 7 is a partial cross-sectional view of the electron emitting device shown in FIG. 1 under manufacturing process;

FIG. 8 is a graph showing the polarization-element voltage characteristic (Q-V characteristic) of the electron emitting device shown in FIG. 1;

FIG. 9 shows a state of the electron emitting device shown in FIG. 1 when the device accumulates electrons;

FIG. 10 shows another state of the electron emitting device shown in FIG. 1 when the device emits electrons;

FIG. 11 is a partial cross-sectional view of an electron emitting device according to a second embodiment of the present invention;

FIG. 12 is a partial cross-sectional view of an electron emitting device according to a third embodiment of the present invention;

FIG. 13 is a partial cross-sectional view of an electron emitting device according to a fourth embodiment of the present invention;

FIG. 14 is a partial cross-sectional view of an electron emitting device according to a fifth embodiment of the present invention;

FIG. 15 shows a state of a conventional electron emitting device;

FIG. 16 is a graph showing the polarization-element voltage characteristic (Q-V characteristic) of the conventional electron emitting device shown in FIG. 15;

FIG. 17 shows another state of the conventional electron emitting device shown in FIG. 15;

FIG. 18 shows another state of the conventional electron emitting device shown in FIG. 15;

FIG. 19 is a partial cross-sectional view of the conventional electron emitting device shown in FIG. 15 for explaining its operation.

Claims

1. A electron emitting device comprising: an emitter section composed of a dielectric material;a lower electrode disposed on the lower side of the emitter section; andan upper electrode disposed above the emitter section to oppose the lower electrode with the emitter section therebetween, the upper electrode having a plurality of micro through holes, a surface of a periphery of each micro through hole facing the emitter section being apart from the emitter section by a predetermined gap distance;wherein electrons are accumulated on an upper surface of the emitter section when dipoles of the emitter section reverse in such a manner that negative poles of the dipoles are oriented toward the lower electrode in the case where potential of the upper electrode is lower than potential of the lower electrode, and electrons accumulated on the upper surface of the emitter section are emitted through the micro through holes when the dipoles of the emitter section reverse in such a manner that negative poles of the dipoles are oriented toward the upper electrode in the case where potential of the upper electrode is higher than potential of the lower electrode, andwherein the upper electrode is configured in such a manner that said predetermined gap distance is substantially constant for any of said micro through holes.

2. The electron emitting device according to claim 1, wherein said upper electrode comprises; micro through hole forming section which is a thin film-like and in which said micro through holes are formed; andsupporting section which supports said micro through hole forming section against said emitter section in such a manner that the lower surface of the micro through hole forming section is substantially parallel to the upper surface of the emitter section.

3. The electron emitting device according to claim 2, wherein said micro through hole forming section comprises projection portion which projects toward the upper surface of the emitter section.

4. The electron emitting device according to claim 1, a diameter of the micro through hole formed in the upper electrode be 0.1 μm or more and 0.5 μm or less.

5. The electron emitting device according to claim 1, wherein said gap distance is set in such a manner that, when a drive voltage Vin is the sum of an emitter section voltage Vfer and a gap voltage Vgap, the emitter section voltage Vfer is 50% or more of the drive voltage Vin, wherein the drive voltage Vin is a voltage applied between the lower electrode and the upper electrode, the emitter section voltage Vfer is a divided voltage of the drive voltage Vin and is applied to the emitter section between the lower electrode and the upper surface of the emitter section, and the gap voltage Vgap is a divided voltage of the drive voltage Vin applied to space between the upper surface of the emitter section and the lower surface of the upper electrode.