METHOD FOR MANUFACTURING ELECTRON BEAM DEVICE, METHOD FOR MANUFACTURING IMAGE FORMING APPARATUS, ELECTRON BEAM DEVICE AND IMAGE FORMING APPARATUS MANUFACTURED THOSE MANUFACTURING METHODS, METH Number:6,802,753 from the United States Patent and Trademark Office (PTO) owispatent In a manufacturing process of an image forming apparatus (electron beam device) using electron emission elements, particularly, surface conduction type electron emission elements, wirings on an electron source substrate on which the wirings and element electrodes are formed are opposite to electrodes for a face plate, and a given voltage is applied between the wirings and the electrodes to thereby generate a discharge phenomenon in advance, thus removing a protrusion or the like. In this way, when an electric field applying process is conducted on the electron source substrate, a factor such as a protrusion in an electron source which induces a discharge phenomenon in driving an electron beam device represented by an image forming apparatus is removed, thus realizing an image forming apparatus excellent in display characteristic with no defective pixel even in image display for a long period of time.<H MANUFACTURING, MANUFACTURED, METHOD, FOR, MANU, 6802753.html, Patent, pto, 6802753

Title: METHOD FOR MANUFACTURING ELECTRON BEAM DEVICE, METHOD FOR MANUFACTURING IMAGE FORMING APPARATUS, ELECTRON BEAM DEVICE AND IMAGE FORMING APPARATUS MANUFACTURED THOSE MANUFACTURING METHODS, METH

Abstract: In a manufacturing process of an image forming apparatus (electron beam device) using electron emission elements, particularly, surface conduction type electron emission elements, wirings on an electron source substrate on which the wirings and element electrodes are formed are opposite to electrodes for a face plate, and a given voltage is applied between the wirings and the electrodes to thereby generate a discharge phenomenon in advance, thus removing a protrusion or the like. In this way, when an electric field applying process is conducted on the electron source substrate, a factor such as a protrusion in an electron source which induces a discharge phenomenon in driving an electron beam device represented by an image forming apparatus is removed, thus realizing an image forming apparatus excellent in display characteristic with no defective pixel even in image display for a long period of time.

Patent Number: 6,802,753 Issued on 10/12/2004 to Ando, et al.

Inventors: Ando; Yoichi (Inagi, JP); Yamamoto; Keisuke (Yamato, JP); Kawasaki; Hideshi (Machida, JP); Kobayashi; Tamaki (Isehara, JP); Mogi; Satoshi (Yamato, JP); Hayama; Akira (Atsugi, JP)
Assignee: Canon Kabushiki Kaisha (Tokyo, JP)

Appl. No.: 09/722,454

Filed: November 28, 2000

Foreign Application Priority Data


Jan 19, 1999 [JP]			11-011108
Feb 01, 1999 [JP]			11-024249
Feb 19, 1999 [JP]			11-041867
Feb 24, 1999 [JP]			11-047085
Feb 26, 1999 [JP]			11-050508
Feb 26, 1999 [JP]			11-050576

Current U.S. Class: 445/6 ; 445/24; 445/50

Current International Class: H01J 9/02 (20060101)

Field of Search: 445/3,6,24,25,49,50,51

References Cited [Referenced By]

U.S. Patent Documents


5066883	November 1991	Yoshioka et al.
5528108	June 1996	Cisneros
5569974	October 1996	Morikawa et al.
5682085	October 1997	Suzuki et al.
5847495	December 1998	Yamanobe et al.
5853310	December 1998	Nishimura et al.
6306001	October 2001	Hiroki
2002/0132041	September 2002	Yamanobe et al.

Foreign Patent Documents


0660357	Jun., 1995	EP
1-31332	Feb., 1989	JP
2-257551	Oct., 1990	JP
3-55738	Mar., 1991	JP
4-28137	Jan., 1992	JP
7-105850	Apr., 1995	JP
7-192611	Jul., 1995	JP
7-235255	Sep., 1995	JP
8-102250	Apr., 1996	JP
8-162012	Jun., 1996	JP
9-129124	May., 1997	JP
8-106847	Jun., 1997	JP
9-213224	Aug., 1997	JP
9-306336	Nov., 1997	JP
10-255650	Sep., 1998	JP
11-54038	Feb., 1999	JP

Other References

Meyer, et al.; "Recent Development on `Microtips` Display At Leti"; Tech. Dig. of IVMC 91, Nagahama 1991, pp. 6-9. .
Hartwell, et al.; "Strong Electron Emission From Patterned Tin-Indium Oxide Thin Films"; Tech. Dig. 1 EDM, Tech. Pig., Dec. 1-3, 1975, Wash. D.C., pp. 519-521 (1976). .
Spindt, et al.; "Physical Properties Of Thin-Film Field Emission Cathodes With Molybdenum Cones"; J. Appl. Phys. vol. 47, No. 12, Dec. 1976, pp. 5248-5263. .
C.A. Mead; "Operation Of Tunnel-Emission Devices"; J. Appl. Phys. vol. 32, No. 4, Apr. 1961, pp. 646-652. .
Elinson, et al.; "The Emission Of Hot Electrons And The Field Emission Of Electrons From Tin Oxide"; Radio Engineering and Electronic Physics, vol. 10, pp. 1290-1296, (1965). .
G. Dittmer, "Electrical Conduction And Electron Emission Of Discontinuous Thin Films"; Thin Solid Films, vol. 9, pp. 317-328 (1972). .
Dyke, et al., "Field Emission", Advances in Electronics and Electron Physics, vol. III, Academic Press, 89-184 (1956). .
Araki, et al., "Electroforming and Electron Emission of Carbon Thin Films"; J. Vac. Soc. Japan, vol. 26, No. 1, pp. 22-29 (1981). .
High Voltage Technology, Electric Institute, Ohm Company, pp. 38, 39 (1981)..

Primary Examiner: Patel; Nimeshkumar D.
Assistant Examiner: Santiago; Mariceli
Attorney, Agent or Firm: Fitzpatrick, Cella, Harper & Scinto

Parent Case Text

This application is a continuation of International Application No. PCT/JP00/00228, filed Jan. 19, 2000, which claims the benefit of Japanese Patent Applications as follows: 1) 11-011108 filed on Jan. 19, 1999 2) 11-024249 filed on Feb. 1, 1999 3) 11-041867 filed on Feb. 19, 1999 4) 11-047085 filed on Feb. 24, 1999 5) 11-050508 filed on Feb. 26, 1999 6) 11-050576 filed on Feb. 26, 1999

Claims

What is claimed is:

1. A method of manufacturing an electron beam device in which electron emission portions that emit electrons and wirings that electrically connect the electron emission portions are disposed on a substrate, the method comprising: a wiring forming step of forming at least one wiring on the substrate; and an electron emission portion forming process of forming the electron emission portions on the substrate, wherein an electric field applying process of applying a given electric field to the substrate on which the at least one wiring is formed is conducted using an electrode opposing a surface on the substrate on which the at least one wiring is formed, after the wiring forming step is completed and before said electron emission portion forming process is completed, and wherein the electric field is 1 kV/mm or more in its electric field intensity.

2. The method of manufacturing the electron beam device according to claim 1, wherein said electron emission portion forming step includes an electrode forming step of forming a pair of electrodes to which different potentials are given from the wirings in correspondence with respective ones of the electron emission portions, and said electric field applying process is conducted before said electrode forming step is conducted.

3. The method of manufacturing the electron beam device according to claim 2, wherein the pair of electrodes comprise an emitter and a gate of the electric field emission type electron emission element.

4. The method of manufacturing the electron beam device according to claim 2, wherein the pair of electrodes comprise a pair of electrodes that constitute surface conduction type electron emission elements.

5. The method of manufacturing the electron beam device according to claim 4, wherein said electrode forming step comprises a step which includes a thin film forming step of forming an electrically conductive thin film on the substrate, and produces a gap in the electrically conductive thin film and constitutes the pair of electrodes by the electrically conductive thin film which exists on both sides of the gap.

6. A method of manufacturing an electron beam device in which electron emission portions that emit electrons and wirings that electrically connect the electron emission portions are disposed on a substrate, the method comprising: a wiring forming step of forming at least one wiring on the substrate; and an electron emission portion forming process of forming the electron emission portions on the substrate; wherein an electric field applying process of applying a given electric field to the substrate on which the at least one wiring is formed is conducted after said wiring forming step is completed and before said electron emission portion forming process is completed, and wherein said electric field applying process comprises a step of discharging, by application of the electric field, electricity from a portion of the substrate from which electricity is liable to be discharged in various processes after said electric field applying process including said electron emission portion forming process, or when said electron beam device is used, to thereby change the portion of the substrate into a shape which is difficult to discharge electricity.

7. A method of manufacturing an electron beam device in which electron emission portions that emit electrons and wirings that electrically connect the electron emission portions are disposed on a substrate, the method comprising: a wiring forming step of forming at least one wiring on the substrate; and an electron emission portion forming process of forming the electron emission portions on the substrate, wherein an electric field applying process of applying a given electric field to the substrate on which the at least one wiring is formed is conducted after said wiring forming step is completed and before said electron emission portion forming process is completed, wherein said electron emission portion forming step includes an electrode forming step of forming a pair of electrodes to which different potentials are given from the wirings in correspondence with respective ones of the electron emission portions, and said electric field applying process is conducted before said electrode forming step is conducted, wherein the pair of electrodes comprise a pair of electrodes that constitute surface conduction type electron emission elements, wherein said electrode forming step comprises a step which includes a thin film forming step of forming an electrically conductive thin film on the substrate, and produces a gap in the electrically conductive thin film and constitutes the pair of electrodes by the electrically conductive thin film which exists on both sides of the gap, and wherein said electric field applying process is conducted before said thin film forming step is conducted.

8. A method of manufacturing an electron beam device in which electron emission portions that emit electrons and wirings that electrically connect the electron emission portions are disposed on a substrate, the method comprising: a wiring forming step of forming at least one wiring on the substrate; and an electron emission portion forming process of forming the electron emission portions on the substrate; wherein an electric field applying process of applying a given electric field to the substrate on which the wiring is formed is conducted after said wiring forming step is completed and before said electron emission portion forming process is completed, wherein said electron emission portion forming step includes an electrode forming step of forming a pair of electrodes to which different potentials are given from the wirings in correspondence with respective ones of the electron emission portions, and said electric field applying process is conducted before said electrode forming step is conducted, wherein the pair of electrodes comprise a pair of electrodes that constitute surface conduction type electron emission elements, wherein said electrode forming step comprises a step which includes a thin film forming step of forming an electrically conductive thin film on the substrate, and produces a gap in the electrically conductive thin film and constitutes the pair of electrodes by the electrically conductive thin film which exists on both sides of the gap, and wherein said electric field applying process is conducted after said thin film forming step is completed and before the gap is produced in the electrically conductive thin film.

9. A method of manufacturing an electron beam device in which electron emission portions that emit electrons and wirings that electrically connect the electron emission portions are disposed on a substrate, the method comprising: a wiring forming step of forming at least one wiring on the substrate; and an electron emission portion forming process of forming the electron emission portions on the substrate; wherein an electric field applying process of applying a given electric field to the substrate on which the at least one wiring is formed is conducted using an electrode opposing a surface of the substrate on which the at least one wiring is formed after said wiring forming step is completed and before said electron emission portion forming process is completed, said electron emission portion forming step includes an electrode forming step of forming a pair of electrodes to which different potentials are given from said wirings in correspondence with respective ones of the electron emission portions, and said electric field applying process is conducted before said electrode forming step is conducted, and the pair of electrodes comprise an emitter and a gate of an electric field emission type electron emission element, said electric field applying process is conducted before the emitter is formed.

10. The method of manufacturing the electron beam device according to claim 9, wherein the electric field emission type electron emission element comprises the emitter that emits electrons from an end portion and the gate that produces an electric field between the end portion and the gate.

11. The method of manufacturing the electron beam device according to claim 9, wherein said electric field applying process is conducted before the gate is formed.

12. The method of manufacturing the electron beam device according to claim 11, wherein the plurality of electron emission portions are connected onto one main surface of the substrate in the form of a ladder or a matrix by the wirings.

13. The method of manufacturing the electron beam device according to claim 12, wherein, in said electric field applying process, the electrode is disposed opposite to a surface of the substrate on which the wirings are disposed, and a voltage is applied between the electrode and the wirings on the substrate to apply the electric field.

14. The method of manufacturing the electron beam device according to claim 12, wherein a voltage given between the electrode and the wirings is changed during said electric field applying process.

15. A method of manufacturing an electron beam device in which electron emission portions that emit electrons and wirings that electrically connect the electron emission portions are disposed on a substrate, the method comprising: a wiring forming step of forming at least one wiring on the substrate; and an electron emission portion forming process of forming the electron emission portions on the substrate; wherein an electric field applying process of applying a given electric field to the substrate on which the at least one wiring is formed is conducted using an electrode opposing a surface of the substrate on which the at least one wiring is formed after said wiring forming step is completed and before said electron emission portion forming process is completed, wherein said electron emission portion forming step includes an electrode forming step of forming a pair of electrodes to which different potentials are given from the wirings in correspondence with respective ones of the electron emission portions, and said electric field applying process is conducted before said electrode forming step is conducted, wherein the pair of electrodes comprise an emitter and a gate of the electric field emission type electron emission element, wherein said electric field applying process is conducted before the emitter is formed, wherein said electric field applying process is conducted before the gate is formed, wherein the plurality of electron emission portions are connected onto one main surface of the substrate in the form of a ladder or a matrix by the wirings, and wherein a distance between the electrode and the wirings is changed during the electric field applying process.

16. A method of manufacturing an electron beam device in which electron emission portions that emit electrons and wirings that electrically connect the electron emission portions are disposed on a substrate, the method comprising: a wiring forming step of forming at least one wiring on the substrate; and an electron emission portion forming process of forming the electron emission portions on the substrate; wherein an electric field applying process of applying a given electric field to the substrate on which the at least one wiring is formed is conducted using an electrode opposing a surface of the substrate on which the at least one wiring is formed after said wiring forming step is completed and before said electron emission portion forming process is completed, wherein said electron emission portion forming step includes an electrode forming step of forming a pair of electrodes to which different potentials are given from the wirings in correspondence with respective ones of the electron emission portions, and said electric field applying process is conducted before said electrode forming step is conducted, wherein the pair of electrodes comprise an emitter and a gate of the electric field emission type electron emission element, wherein said electric field applying process is conducted before the emitter is formed, wherein said electric field applying process is conducted before the gate is formed, wherein the plurality of electron emission portions are connected onto one main surface of the substrate in the form of a ladder or a matrix by the wirings, and wherein a current limit resistor is connected between the electrode and a power supply that applies a voltage to the electrode.

17. A method of manufacturing an electron beam device in which electron emission portions that emit electrons and wirings that electrically connect the electron emission portions are disposed on a substrate, the method comprising: a wiring forming step of forming at least one wiring on the substrate; and an electron emission portion forming process of forming the electron emission portions on the substrate; wherein an electric field applying process of applying a given electric field to the substrate on which the at least one wiring is formed is conducted after said wiring forming step is completed and before said electron emission portion forming process is completed, wherein said electron emission portion forming step includes an electrode forming step of forming a pair of electrodes to which different potentials are given from the wirings in correspondence with respective ones of the electron emission portions, and said electric field applying process is conducted before said electrode forming step is conducted, wherein the pair of electrodes comprise an emitter and a gate of the electric field emission type electron emission element, wherein said electric field applying process is conducted before the emitter is formed, wherein said electric field applying process is conducted before the gate is formed, wherein the plurality of electron emission portions are connected onto one main surface of the substrate in the form of a ladder or a matrix by the wirings, and wherein said electric field applying process is conducted in a vacuum atmosphere.

18. A method of manufacturing an electron beam device in which electron emission portions that emit electrons and wirings that electrically connect the electron emission portions are disposed on a substrate, the method comprising: a wiring forming step of forming at least one wiring on the substrate; and an electron emission portion forming process of forming the electron emission portions on the substrate; wherein an electric field applying process of applying a given electric field to the substrate on which the at least one wiring is formed is conducted using an electrode opposing a surface of the substrate on which the at least one wiring is formed after said wiring forming step is completed and before said electron emission portion forming process is completed, wherein said electron emission portion forming step includes an electrode forming step of forming a pair of electrodes to which different potentials are given from the wirings in correspondence with respective ones of the electron emission portions, and said electric field applying process is conducted before said electrode forming step is conducted, wherein the pair of electrodes comprise an emitter and a gate of the electric field emission type electron emission element, wherein the electric field emission type electron emission element comprises the emitter that emits electrons from an end portion and the gate that produces an electric field between the end portion and the gate, wherein said electric field applying process is conducted before the emitter is formed, wherein said electric field applying process is conducted before the gate is formed, wherein the plurality of electron emission portions are connected onto one main surface of the substrate in the form of a ladder or a matrix by the wirings, and wherein a distance between the electrode and the wirings is changed during the electric field applying process.

19. A method of manufacturing an electron beam device in which electron emission portions that emit electrons and wirings that electrically connect the electron emission portions are disposed on a substrate, the method comprising: a wiring forming step of forming at least one wiring on the substrate; and an electron emission portion forming process of forming the electron emission portions on the substrate; wherein an electric field applying process of applying a given electric field to the substrate on which the at least one wiring is formed is conducted using an electrode opposing a surface of the substrate on which the at least one wiring is formed after said wiring forming step is completed and before said electron emission portion forming process is completed, wherein said electron emission portion forming step includes an electrode forming step of forming a pair of electrodes to which different potentials are given from the wirings in correspondence with respective ones of the electron emission portions, and said electric field applying process is conducted before said electrode forming step is conducted, wherein the pair of electrodes comprise an emitter and a gate of the electric field emission type electron emission element, wherein the electric field emission type electron emission element comprises the emitter that emits electrons from an end portion and the gate that produces an electric field between the end portion and the gate, wherein said electric field applying process is conducted before the emitter is formed, wherein said electric field applying process is conducted before the gate is formed, wherein the plurality of electron emission portions are connected onto one main surface of the substrate in the form of a ladder or a matrix by the wirings, and wherein a current limit resistor is connected between the electrode and a power supply that applies a voltage to the electrode.

20. A method of manufacturing an electron beam device in which electron emission portions that emit electrons and wirings that electrically connect the electron emission portions are disposed on a substrate, the method comprising: a wiring forming step of forming at least one wiring on the substrate; and an electron emission portion forming process of forming the electron emission portions on the substrate; wherein an electric field applying process of applying a given electric field to the substrate on which the at least one wiring is formed is conducted after said wiring forming step is completed and before said electron emission portion forming process is completed, wherein said electron emission portion forming step includes an electrode forming step of forming a pair of electrodes to which different potentials are given from the wirings in correspondence with respective ones of the electron emission portions, and said electric field applying process is conducted before said electrode forming step is conducted, wherein the pair of electrodes comprise an emitter and a gate of the electric field emission type electron emission element, wherein the electric field emission type electron emission element comprises the emitter that emits electrons from an end portion and the gate that produces an electric field between the end portion and the gate, wherein said electric field applying process is conducted before the emitter is formed, wherein said electric field applying process is conducted before the gate is formed, wherein the plurality of electron emission portions are connected onto one main surface of the substrate in the form of a ladder or a matrix by the wirings, and wherein said electric field applying process is conducted in a vacuum atmosphere.

21. A method of manufacturing an image forming apparatus provided with a rear plate on which are disposed a pair of device electrodes, an electroconductive film disposed between the pair of device electrodes and having an electron emitting portion emitting at least one electron and a wiring connected electrically to the pair of device electrodes, and a face plate on which an image forming member is disposed, the method comprising: a wiring forming step of forming the wiring on the rear plate; a device electrode forming step of forming the pair of device electrodes connected electrically to the wiring on the rear plate; an electroconductive film forming step of forming the electroconductive film between the pair of device electrodes on the rear plate; an electron emitting portion forming step of forming the electron emitting portion on the electroconductive film after the electroconductive film forming step; a sealing step of providing sealing between the rear plate and the face plate on which the image forming member is disposed; and a voltage applying step wherein, after completing the wiring forming step and the device electrode forming step, before the electron emitting portion forming step and the sealing step, an electrode is disposed in opposition to the rear plate on which the wiring and the device electrodes are disposed, and a voltage is applied between the electrode and the rear plate, wherein the voltage applying step is conducted to cause an electrical discharging between the electrode and the rear plate.

22. A method of manufacturing an image forming apparatus provided with a rear plate on which are disposed a pair of device electrodes, an electroconductive film disposed between the pair of device electrodes and having an electron emitting portion emitting at least one electron and a wiring connected electrically to the pair of device electrodes, and a face plate on which an image forming member is disposed, the method comprising: a wiring forming step of forming the wiring on the rear plate; a device electrode forming step of forming the pair of device electrodes connected electrically to the wiring on the rear plate; an electroconductive film forming step of forming the electroconductive film between the pair of device electrodes on the rear plate; an electron emitting portion forming step of forming the electron emitting portion on the electroconductive film after the electroconductive film forming step; a sealing step of providing sealing between the rear plate and the face plate on which the image forming member is disposed; and a voltage applying step wherein, after completing the wiring forming step, the device electrode forming step and the electroconductive film forming step, before the electron emitting portion forming step and the sealing step, an electrode is disposed in opposition to the rear plate on which the wiring, the device electrodes and the electroconductive film are disposed, and a voltage is applied between the electrode and the rear plate, wherein the voltage applying step is conducted to cause an electrical discharging between the electrode and the rear plate.

23. A method of manufacturing an image forming apparatus provided with a rear plate on which an electron emitting portion emitting at least one electron and a wiring connected electrically to the electron emitting portion are disposed, and a face plate on which an image forming member is disposed, the method comprising: a wiring forming step of forming the wiring on the rear plate; an electron emitting portion forming step of forming the electron emitting portion on the rear plate; a sealing step of sealing between the rear plate and the face plate on which the image forming member is disposed; and a voltage applying step wherein, after completing the wiring forming step, before the electron emitting portion forming step and the sealing step, an electrode is disposed in opposition to the rear plate on which the wiring is disposed, and a voltage is applied between the electrode and the rear plate, wherein the voltage applying step is conducted to cause an electrical discharging between the electrode and the rear plate.

24. The method according to claim 23, wherein the voltage applying step is a step of applying an electric field of 1 kV/m or greater between the electrode and the rear plate.

25. The method according to claim 23, wherein the voltage applying step is conducted within a depressurized atmosphere.

26. The method according to claim 23, wherein the voltage applying step is conducted within a gas containing atmosphere.

27. The method according to claim 23, wherein the voltage applied between the electrode and the rear plate changes during the voltage applying step.

28. The method according to claim 27, wherein the voltage is a D.C. voltage gradually increasing from a lower voltage.

29. The method according to claim 27, wherein the voltage is an A.C. voltage gradually increasing from a lower voltage.

30. The method according to claim 27, wherein the voltage is a pulse voltage gradually increasing from a lower voltage.

31. The method according to claim 27, wherein a distance between the electrode and the rear plate is changed during the voltage applying step.

32. A method of manufacturing an image forming apparatus provided with a rear plate on which an electroconductive film having an electron emitting portion emitting at least one electron and a wiring connected electrically to the electroconductive film are disposed, and a face plate on which an image forming member is disposed, the method comprising: a wiring forming step of forming the wiring on the rear plate; an electroconductive film forming step of forming the electroconductive film electrically connected to the wiring on the rear plate; an electron emitting portion forming step of forming the electron emitting portion on the electroconductive film after the electroconductive film forming step; a sealing step of providing sealing between the rear plate and the face plate on which the image forming member is disposed; and a voltage applying step wherein, after completing the wiring forming step and the electroconductive film forming step, before the electron emitting portion forming step and the sealing step, an electrode is disposed in opposition to the rear plate on which the wiring and the electroconductive film are disposed, and a voltage is applied between the electrode and the rear plate, wherein the voltage applying step is conducted to cause an electrical discharging between the electrode and the rear plate.

33. The method according to claim 32, wherein the electron emitting portion forming step for forming the electron emitting portion on the electroconductive film is a step of forming a gap in the electroconductive film.

34. The method according to claim 33, wherein the step of forming the gap in the electroconductive film includes a step of energizing the electroconductive film.

35. The method according to claim 33, wherein after the step of forming the gap in the electroconductive film, a further step of depositing a deposit on or in a vicinity of the electron emitting portion is conducted.

36. The method according to claim 32, wherein the voltage applying step is conducted such that, at applying a voltage between the electrode and the rear plate, an energy stored in a capacitor formed by the electrode and the rear plate is smaller than an energy which destroys the electroconductive film.

37. The method according to claim 36, wherein an area S where the electrode and the rear plate face each other, a distance Hc between the electrode and the rear plate, a voltage Vc applied between the electrode and the wiring, a dielectric constant .di-elect cons. of a vacuum, and an energy Eth by which the electrically conductive thin film is destroyed, meet following condition:

Description

TECHNICAL FIELD

The present invention relates to an electron beam device in which a plurality of electron emission portions are formed on a substrate, an image forming apparatus in which an image forming member is formed opposite to the electron emission portions and a method of manufacturing those devices.

BACKGROUND ART

Up to now, as the electron emitting elements, there have been known the two kinds of a hot cathode element and a cold cathode element. As the cold cathode element of those elements, there have been known, for example, a surface conduction type electron emission element, a field emission element (hereinafter referred to as "FlE type"), a metal/insulating layer/metal type emission element (hereinafter referred to as "MIM type"), etc.

As the surface conduction type electron emission elements, there have been known, for example, an example disclosed in Radio Eng. Electron Phys., 10, 1290 (1965) by M. I. Elinson, or other examples which will be described later.

The surface conduction type electron emission element utilizes a phenomenon in which electron emission occurs by allowing a current to flow into a small-area thin film formed on a substrate in parallel to a film surface. As the surface conduction type electron emission element, there have been reported a surface conduction type electron emission element using an SiO.sub.2 thin film by the above-mentioned Elinson and others, a surface conduction type electron emission element using an Au thin film [G. Dittmer: "Thin Solid Films", 9,317 (1972)], a surface conduction type electron emission element using an In.sub.2 O.sub.3 /SnO.sub.2 thin film [M. Hartwell an C. G. Fonstad: "IEEE Trans. ED Conf.", 519(1975)], a surface conduction type electron emission element using a carbon thin film ["Vapor Vacuum," Vol. 26, No. 1, p 22 (1983), by Hisashi Araki, et al.], etc.

As a typical example of those surface conduction type electron emission elements, a plan view of the above-mentioned element by M. Hartwell is shown in FIG. 93. In FIG. 93, reference numeral 8001 denotes a substrate, and reference numeral 8004 denotes an electrically conductive thin film that is made of a metal oxide formed through sputtering. The electrically conductive film 8004 is formed in an H-shaped plane as shown in FIG. 93. An electrifying process called "electrification forming" which will be described later is conducted on the electrically conductive thin film 8004 to form an electron emission portion 8005. In FIG. 93, an interval L is set to 0.5 to 1 (mm), and W is set to 0.1 (mm). For convenience of showing in the figure, the electron emission portion 8005 is shaped in a rectangle in the center of the electrically conductive thin film 8004. However, this shape is schematic and does not faithfully express the position and the configuration of the actual electron emission portion.

In the above-mentioned surface conduction type electron emission elements including the element proposed by M. Hartwell, et al., the electron emission portion 8005 is generally formed on the electrically conductive film 8004 through the electrifying process which is called "electrification forming" before the electron emission is conducted. In other words, the electrification forming is directed to a process in which a constant d.c. voltage or a d.c. voltage that steps up at a very slow rate such as about 1 V/min is applied to both ends of the electrically conductive film 8004 and electrified, to thereby locally destroy, deform or affect the electrically conductive film 8004, thus forming the electron emission portion 8005 which is in an electrically high-resistant state. A crack occurs in a part of the electrically conductive film 8004 which has been locally destroyed, deformed or affected. In the case where an appropriate voltage is applied to the electrically conductive thin film 8004 after the above electrification forming, electron emission is conducted from a portion close to the crack.

Examples of the FE type have been known from "Field Emission" of Advance in Electron Physics, 8, 89 (1956) by W. P. Dyke and W. W. Dolan, "Physical properties of thin-film field emission cathodes with molybdenum cones" of J. Appl. Phys., 47,5248 (1976), by C. A. Spindt, etc.

As a typical example of the element structure of the FE element, FIG. 94 shows a cross-sectional view of the elements made by the above-mentioned C. A. Spindt, et al. In this figure, reference numeral 8010 denotes a substrate, 8011 is an emitter wiring made of an electrically conductive material, 8012 is an emitter cone, 8013 is an insulating layer, and 8014 is a gate electrode. The element of this type is so designed as to apply an appropriate voltage between the emitter cone 8012 and the gate electrode 8014 to produce electric field emission from a leading portion of the emitter cone 8012.

Also, as another element structure of the FE type, there is an example in which an emitter and a gate electrode are disposed on a substrate substantially in parallel with the substrate plane, without using a laminate structure shown in FIG. 94.

Also, as an example of the MIM type, there has been known, for example, "Operation of tunnel-emission devices," J. Appl. Phys., 32,646 (1961) by C. A. Mead, etc. A typical example of the element structure of the MIM type is shown in FIG. 95. FIG. 95 is a cross-sectional view, and in the figure, reference numeral 8020 denotes a substrate, 8021 is a lower electrode made of metal, 8022 is a thin insulating layer about 10 nm in thickness, and 8023 is an upper electrode made of metal about 8 to 30 nm in thickness. In the MIM type, an appropriate voltage is applied between the upper electrode 8023 and the lower electrode 8021, to thereby produce electron emission from the surface of the upper electrode 8023.

The above-mentioned cold cathode element does not require a heater for heating because it can obtain electron emission at a low temperature as compared with the hot cathode element. Accordingly, the cold cathode element is simpler in structure than the hot cathode element and can prepare a fine element. Also, in the cold cathode element, even if a large number of elements are disposed on the substrate with a high density, a problem such as heat melting of the substrate is difficult to occur. Further, the cold cathode element is advantageous in that a response speed is high which is different from the hot cathode element which is low in the response speed because it operates due to heating by the heater. For the above-mentioned reasons, a study for applying the cold cathode elements has been extensively conducted.

For example, the surface conduction type electron emission element has the advantage that a large number of elements can be formed on a large area since it is particularly simple in structure and easy to manufacture among the cold cathode elements.

For that reason, a method in which a large number of elements are arranged and driven has been studied as disclosed in JP-A-64-31332 by the present applicant.

As the application of the surface conduction type electron emission element, for example, an image display device, an image forming apparatus such as an image recording device, a charge beam source, and so on have been studied.

In particular, as the application to the image display device, there has been studied an image display device using the combination of the surface conduction type electron emission element with a phosphor that emits light by irradiation of an electron beam as disclosed in for example U.S. Pat. No. 5,066,883 by the present applicant, JP-A-2-257551, and JP-A-4-28137. In the image display device using the combination of the surface conduction type electron emission element with the phosphor, the characteristic superior to the conventional other image display devices is expected. For example, even as compared with the liquid crystal display device which has been spreading in recent years, the above image display device is excellent in that no back light is required because it is of the self light emitting type and the angle of visibility is broad.

Also, a method in which a large number of FE type elements are disposed and driven is disclosed in, for example, U.S. Pat. No. 4,904,895 by the present applicant. Also, as an example of applying the FE type to the image display device, there has been known, for example, a plate type display device reported by R. Meyer [R. Meyer: "Recent Development on Micro-tips Display at LETI", Tech. Digest of 4th Int. Vacuum Micro-electronics Conf., Nagahama, pp. 6 to 9 (1991].

Also, an example in which a large number of MIM type elements are arranged and applied to an image display device is disclosed in, for example, JP-A-3-55738 by the present applicant.

Among the image forming apparatuses using the above-mentioned electron emission element, attention has been paid to the flat type image display device thin in depthwise as a replacement of the CRT type image display device since the space is saved and the weight is light.

FIG. 96 is a perspective view showing an example of a display panel portion which forms a plane-type image display device, in which a part of the panel is cut off in order to show the internal structure.

In FIG. 96, reference numeral 8115 denotes a rear plate, 8116 a side wall, 8117 a face plate, and the rear plate 8115, the side wall 8116 and the face plate 8117 form an envelope (airtight vessel) for maintaining the interior of the display panel in a vacuum state.

The rear plate 8115 is fixed with a substrate 8111, and N.times.M cold cathode elements 8112 are formed on the substrate 8111 (N and M are positive integers of equal to or larger than 2 or more and appropriately set in accordance with the target number of display pixels). Also, the N.times.M cold cathode elements 8112 are wired by M row wirings 8113 and N column wirings 8114 as shown in FIG. 96. A portion made up of the substrate 8111, the cold cathode elements 8112, the row wirings 8113 and the column wirings 8114 is called the multiple electron beam source. Also, at least in portions where the row wirings 8113 and the column wirings 8114 cross each other, an insulating layer (not shown) between both of the wirings is formed to keep electric insulation.

A lower surface of the face plate 8117 is formed with a fluorescent film 8118 formed of a phosphor on which phosphors (not shown) of three primary colors consisting of red (R), green (G) and blue (B) are separately painted. Also, black material (not shown) are disposed between the respective color phosphors which form the fluorescent film 8118, and a metal back 8119 made of Al or the like is formed on a surface of the fluorescent film 8118 on the rear plate 8115 side.

Dx1 to Dxm, Dy1 to Dyn and Hv are electric connection terminals with an airtight structure provided for electrically connecting the display panel to an electric circuit not shown. Dx1 to Dxm are electrically connected to the row wirings 8113 of the multiple electron beam source, Dy1 to Dyn are electrically connected to the column wirings 8114 of the multiple electron beam source, and Hv is electrically connected to the metal back 8119, respectively.

Also, the interior of the above airtight vessel is maintained in a vacuum state of about 1.times.10.sup.-4 Pa, and there is required means for preventing the deformation or destruction of the rear plate 8115 and the face plate 8117 due to a pressure difference between the interior of the airtight vessel and the external, as a display area of the image display device increases. In a method of thickening the rear plate 8115 and the face plate 8117, not only does the weight of the image display device increase, but also a distortion of an image or a parallax occurs when viewing the display device from an oblique direction. On the contrary, in FIG. 96, there is provided a structure support (called spacer or rib) 8120 which is formed of a relatively thin glass substrate for supporting the atmospheric pressure. With this structure, a space of normally sub mm to several mm is kept between the substrate 8111 on which the multiple beam electron source is formed and the face plate 8117 on which the fluorescent film 8118 is formed, and the interior of the airtight vessel is maintained in a high vacuum state as described above.

In the image display device using the display panel as described above, when a voltage is applied to the respective cold cathode elements 8112 through the vessel external terminals Dx1 to Dxm and Dy1 to Dyn, electrons are emitted from the respective cold cathode elements 8112. At the same time, with the application of a high voltage of several hundreds (V) to several (kV) to the metal back 8119 through the vessel external terminal Hv, the above emitted electrons are accelerated and allowed to collide with an inner surface of the face plate 8117. As a result, the phosphors of the respective colors which form the fluorescent film 8118 are excited and emit light, thus displaying an image.

In general, electrons emitted from the electron source are accelerated by a voltage (accelerating voltage) applied between the electron source and the phosphor and collide with the phosphor to emit a light. Accordingly, a display image becomes higher in luminance as the accelerating voltage is larger. However, as described above, in a case of a thin-type image forming apparatus in which an opposite distance between the electron source and a substrate having the phosphor is shortened, an electric field intensity formed between the electron source and the phosphor becomes large due to the accelerating voltage.

The above case suffers from the following problems.

In the case where a high electric field is applied to the electron source, specifically, a high voltage of several hundreds V or higher (that is, a high electric field of 1 kV/mm or higher)) is applied between the multiple beam electron source and the face plate 8117 in order to accelerate the emitted electrons from the cold cathode element 8112, and for example, foreign material such as dust, a protrusion or the like (hereinafter generically named protrusion) exists on the electron source. There is a case where the electric field concentrates to the protrusion, and the electrons are emitted therefrom. The configuration of the protrusion further becomes sharp due to an influence of a heat caused by the emitted current or of the high electric field, the electric field intensity becomes further higher, and the amount of emitted electrons increases.

When a positive feedback is effected as described above, there finally occurs such a phenomenon that the projection is thermally destroyed.

When the above phenomenon occurs as described above, not only the protrusion is destroyed but also the vacuum atmosphere within the image forming apparatus is deteriorated. This acts as a trigger and a discharge phenomenon occurs between the electron source and the phosphor to which the high electric field is applied. The accelerated cations collide with the electron source to damage the electron source, resulting in such a problem that an image defect is induced.

As a method of suppressing the above discharge phenomenon, there has been known, for example, a method in which, in order to suppress spark discharge, the spark discharge is conducted in a high vacuum in advance (for example, "high voltage technology" (Electric Institute, Ohm Company 1981)). The above processing is usually called "conditioning".

In manufacturing a large-area image forming apparatus, there is a case in which the execution of the conditioning process adversely affects the electron emission characteristic. This is because the Joule heat consumed in the element by discharge during the conditioning process destroys the electrically conductive thin film.

FIG. 26 is a diagram showing an equivalent circuit in this process. It is presumed that the above phenomenon is induced by electric charges which are stored in a capacitor made up of an electron source substrate 2071 and an electrode 2010 for high voltage application which conduct the conditioning process.

When a voltage V is applied across a parallel plate capacitor formed of two electrodes each having an area S which are apart from each other at a distance d, the stored electric charge amount Q is represented by Q=CV=.di-elect cons.SV/d. When the same electric field is developed in the conditioning process, an energy E stored in the capacitor made up of the electron source substrate 2071 and the electrode 2010 for high voltage application is represented by E=CV/2=.di-elect cons.SV/2d where .di-elect cons. is the dielectric constant of a material between those two electrodes (or vacuum).

For that reason, when the conditioning process is conducted by using the electron source substrate 2071 and the electrode 2010 for high voltage application which is opposite to the electron source substrate 2071 and identical in area, there arises such a problem that the energy consumed by the electron source substrate during the discharge operation increases in proportion to the area.

Also, as another method of suppressing the above discharge phenomenon, there is disclosed in JP-A-8-106847 a technique in which an inductor is disposed between an anode and an external voltage source for the purpose of limiting a large current that flows in an emitter (cathode) as an electric arc through the anode from the external voltage source during arc discharge operation when the arc discharge occurs. In the present specification, the abnormal discharge includes the above-described arc discharge.

The outline of the technique disclosed in the above-described JP-A-8-106847 is schematically shown in FIG. 97. In FIG. 97, reference numeral 9121 denotes a substrate; 9122 is a cathode electrode; 9123 is an emitter; 9124 is a cathode conductor; 9125 is an insulator; 9126 is a gate; 9127 is an anode; 9128 is an inductor; 9129 is a resistor; and 9130 is a voltage source. The technique is that an electric field emission element is used as the electron emission element, and a current which is concerned in the arc discharge between the anode 9127 and the emitter 9123 and supplied from a voltage source 9130 is substantially limited by the provision of the inductor 9128 while the arc discharge occurs between the anode 9127 and the emitter 9123 (cathode). In other words, in the case where the arc discharge occurs and the potential of the anode is lowered, the implantation of electric charges from the external power supply is temporally limited.

However, the large-screen image forming apparatus large in a capacitance between the anode and the cathode electrode suffers from such a problem that the amount of electric charges stored in the anode and the cathode electrode is large, and the electric charges move through a discharge path in response to the deterioration of the potential of the anode when the abnormal discharge starts. In the case where the movement of the electric charges is conducted in a moment, a current value becomes remarkably large. It is needless to say that the current cannot be observed as a current that flows into the anode from the external power supply, that is, the current cannot be suppressed in the above-described method of limiting the implantation of the electric charges from the external power supply.

This is because in the case where the abnormal discharge occurs, the lowered potential of the anode is restored, in other words, only a current that charges the capacitor made up of the anode and the cathode substrate, or a current that connects the arc as a result of the arc discharge is observed. The present inventors have recognized through the measurement of a change in the anode potential with a time during the abnormal discharge that the movement of the electric charges in response to the deterioration of the potential of the anode occurs by a time scale of about .mu. seconds or shorter. Also, the present inventors have recognized that the current corresponding to the drop of the potential of the anode may induce a damage because it flows through the discharge path. Accordingly, in implementation of the conditioning process, it becomes necessary to suppress the current corresponding to the drop of the potential of the anode from flowing through the discharge path.

Also, once the abnormal discharge occurs, there is the possibility that a secondary abnormal discharge occurs, and it is important to prevent the secondary abnormal discharge. It is necessary to surely prevent the secondary abnormal discharge when the secondary abnormal discharge occurs in a linking manner, because there may be a case where a large damage resultantly occurs even if no damage occurs in the first abnormal discharge.

An object of the present invention is to provide a manufacturing method that removes a factor such as a protrusion which induces a discharge phenomenon within an electron beam device represented by an image forming apparatus, to thereby manufacture an excellent electron beam device (electron source) which is high in reliability through the manufacturing method, and to provide an image forming apparatus with no defective pixel even in image display for a long period of time.

Also, another object of the present invention is to provide a manufacturing method and a manufacturing apparatus for an image forming apparatus which suppress a damage caused by abnormal discharge and prevent abnormal discharge which may secondarily occur as much as possible.

DISCLOSURE OF THE INVENTION

According to the present invention, there is provided a method of manufacturing an electron beam device in which electron emission portions that emit electrons and wirings that electrically connect the electron emission portions are disposed on a substrate, the method comprising: a wiring forming step of forming the wiring on the substrate; and an electron emission portion forming process of forming the electron emission portions on the substrate; wherein an electric field applying process of applying a given electric field to the substrate on which the wiring is formed is conducted after the wiring forming step is completed and before the electron emission portion forming process is completed.

In one mode of the method of manufacturing the electron beam device in accordance with the present invention, the electric field is 1 kV/mm or more in its electric field intensity.

In one mode of the method of manufacturing the electron beam device in accordance with the present invention, the electric field applying steps comprises a step of discharging, by application of the electric field, electricity from a portion of the substrate from which electricity is liable to be discharged in various processes after the electric field applying process including the electron emission portion forming process, or when the electron beam device is used, to thereby change the portion into a shape which is difficult to discharge electricity.

In one mode of the method of manufacturing the electron beam device in accordance with the present invention, the electron emission portion forming step includes an electrode forming step of forming a pair of electrodes to which different potentials are given from the wirings in correspondence with the respective electron emission portions, and the electric field applying step is conducted before the electrode forming step is conducted.

In one mode of the method of manufacturing the electron beam device in accordance with the present invention, the pair of electrode comprise a pair of electrodes that constitute surface conduction type electron emission elements.

In one mode of the method of manufacturing the electron beam device in accordance with the present invention, the electrode forming step comprises a step which includes a thin film forming step of forming an electrically conductive thin film on the substrate, and produces a gap in the formed electrically conductive thin film and constitutes the pair of electrodes by the electrically conductive thin films which exists on both sides of the gap.

In one mode of the method of manufacturing the electron beam device in accordance with the present invention, the electric field applying step is conducted before the thin film forming step is conducted.

In one mode of the method of manufacturing the electron beam device in accordance with the present invention, the electric field applying step is conducted after the thin film forming step is completed and before the gap is produced in the electrically conductive thin film.

In one mode of the method of manufacturing the electron beam device in accordance with the present invention, the pair of electrodes comprise an emitter and a gate of the electric field emission type electron emission element.

In one mode of the method of manufacturing the electron beam device in accordance with the present invention, the electric field emission type electron emission element comprises the emitter that emits electrons from an end portion and the gate that produces an electric field between the end portion and the gate.

In one mode of the method of manufacturing the electron beam device in accordance with the present invention, the electric field applying step is conducted before the emitter is formed.

In one mode of the method of manufacturing the electron beam device in accordance with the present invention, the electric field applying step is conducted before the gate is formed.

In one mode of the method of manufacturing the electron beam device in accordance with the present invention, the plurality of electron emission portions are connected onto one main surface of the substrate in the form of a ladder or a matrix by the wirings.

In one mode of the method of manufacturing the electron beam device in accordance with the present invention, in the electric field applying step, an electrode is disposed opposite to a surface of the substrate on which the wirings are disposed, and a voltage is applied between the electrode and the wirings on t