Electron emitter

• US 20060290255A1
• Filed: 06/21/2006
• Published: 12/28/2006
• Est. Priority Date: 06/23/2005
• Status: Active Grant

• Current Assignee: NGK Insulators Limited
• Original Assignee: NGK Insulators Limited
• Inventors: Yamaguchi, Hirofumi, Sato, Kei
• Granted Patent: US 7,723,909 B2
• Time in Patent Office: Days
• US Class Current: 313/310
• CPC Class Codes: H01J 1/312 having an electric field perpendicular to the surface, e.g. tunnel-effect cathodes of metal-insulator-metal [MIM] type H01J1/304- H01J1/308 take precedence
• CPC Class Codes: H01J 1/32 Secondary-electron-emitting electrodes H01J1/35 takes precedence
• CPC Class Codes: H01J 2201/3125 Metal-insulator-Metal [MIM] emission type cathodes

Abstract

A dielectric-film-type electron emitter includes an emitter section, a first electrode, and a second electrode. The emitter section is formed of a thin layer of a polycrystalline dielectric material. The dielectric material constituting the emitter section is formed of a material having high mechanical quality factor (Qm). Specifically, the dielectric material has a Qm higher than that of a so-called low-Qm material (a material having a Qm of 100 or less). The Qm of the dielectric material is preferably 300 or more, more preferably 500 or more.

Claims

1. An electron emitter comprising

an emitter section formed of a thin layer of a dielectric material having a high mechanical quality factor;

a first electrode provided onto a front surface of the emitter section; and

a second electrode provided onto the front surface of the emitter section, or onto a reverse surface of the emitter section opposite the front surface.

2. An electron emitter as described in claim 1, wherein the dielectric material has a mechanical quality factor of more than 100.

3. An electron emitter as described in claim 2, wherein a gap is formed between a peripheral portion of the first electrode and the front surface of the emitter section.

4. An electron emitter as described in claim 3, the electron emitter further comprising a substrate which is provided on the reverse surface side of the emitter section and which supports the emitter section, wherein the emitter section is bonded onto a surface of the substrate.

5. An electron emitter as described in claim 4, wherein the second electrode is bonded onto the surface of the substrate, and the emitter section is bonded onto the second electrode.

6. An electron emitter as described in claim 1, wherein a gap is formed between a peripheral portion of the first electrode and the front surface of the emitter section.

7. An electron emitter as described in claim 6, the electron emitter further comprising a substrate which is provided on the reverse surface side of the emitter section and which supports the emitter section, wherein the emitter section is bonded onto a surface of the substrate.

8. An electron emitter as described in claim 7, wherein the second electrode is bonded onto the surface of the substrate, and the emitter section is bonded onto the second electrode.

9. An electron emitter as described in claim 1, the electron emitter further comprising a substrate which is provided on the reverse surface side of the emitter section and which supports the emitter section, wherein the emitter section is bonded onto a surface of the substrate.

10. An electron emitter as described in claim 9, wherein the second electrode is bonded onto the surface of the substrate, and the emitter section is bonded onto the second electrode.