JPH0927285A - Electron beam generator and image forming device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely prevent an electron source from being charged so as to stabilize an emitted electron orbit by specifying potential within a minimum range. SOLUTION: A faceplate 3 provided with a phosphor film 7 that is made to emit light when bombarded with electrons is opposed to an electron source 1 in which a plurality of electron emitting elements 15 arranged in a matrix are mounted. On the electron source 1, a potential specifying part 9 is provided in which potential is specified to be within a range satisfying tan θ<=2 where θis the angle to a direction perpendicular to the surface of the electron source 1, as seen from the position of the faceplate 3 to which the electrons emitted from the electron emitting elements 15 are applied.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron beam generator and an image forming apparatus such as an image display device using the same, and particularly to an electron beam generator and an image forming apparatus having a large number of surface conduction electron-emitting devices. Regarding

[0002]

2. Description of the Related Art Conventionally, two types of electron-emitting devices, a thermoelectron source and a cold cathode electron source, are known, and an image forming apparatus using these electron sources is also known.

As a plane type image forming apparatus using a thermoelectron source, one shown in FIG. 11 is known. FIG.
FIG. 10 is a schematic configuration diagram of a conventional image forming apparatus using a thermoelectron source. This image forming apparatus is arranged in parallel on an insulating support 1501 and has a plurality of anodes 1502 having a surface coated with a member (phosphor) that emits light by electron beam impact, and an anode 150.
2, a plurality of filaments 1503 arranged in parallel with each other and facing each other, an anode 1502 and a filament 1503.
And a plurality of grids 1504 arranged orthogonally to the anode 1502 and the filament 1503,
The anode 1502, filament 1503 and grid 1504 are held in a transparent container 1505. The container 1505 is airtightly adhered (hereinafter referred to as “sealing”) to the insulating support 1501 so that the inside vacuum can be maintained, and the inside of the envelope configured by the container 1505 and the insulating support 1501 is 10 It is kept in a vacuum of about ^-6 Torr.

The filament 1503 emits electrons by being heated in a vacuum, and by applying an appropriate voltage to the grid 1504 and the anode 1502, the electrons emitted from the filament 1503 collide with the anode 1502, and The phosphor coated on 1502 emits light. Rows of anodes 1502 (X direction) and rows of grids 1504 (Y
By matrix-addressing the (direction), it is possible to control the position of light emission, and an image can be displayed through the container 1505.

However, the image forming apparatus using the thermoelectron source consumes a large amount of power (1). (2) Since the modulation speed is slow, it is difficult to display a large capacity. (3) It is difficult to increase the screen size because variations among elements are likely to occur and the structure is complicated. There is a problem.

Therefore, an image forming apparatus using a cold cathode electron source instead of the thermoelectron source has been considered.

The cold cathode electron source is a field emission type (hereinafter referred to as FE
Type), metal / insulating layer / metal type (hereinafter referred to as MIM type), surface conduction electron-emitting device, and the like.

As an example of the FE type, WPDyke & WWDol
an, "Field emission", Advance in Electron Physics,
8, 89 (1956), or CASPindt, "PHYSICAL Propert
iesof thin-filmfield emission cathodes with moybde
nium coces ", J.Appl.Phys., 47, 5248 (1976) are known.

An example of an image forming apparatus using this FE type electron source will be described with reference to FIG. Figure 12 shows FE
It is the schematic block diagram which partially expanded and showed the conventional image forming apparatus which used the electron source of a mold.

This image forming apparatus, as shown in FIG.
An electron source 2001 having a large number of electron-emitting devices, and a face plate 200 arranged to face the electron source 2001.
And 3. The electron source 2001 is provided on the insulating substrate 201.
1 has a large number of micropoints 2013 electrically connected to each other via conductors 2012 and openings corresponding to the micropoints 2013, and is insulated from the micropoints 2013 by the insulating layer 2014 and is an insulating substrate. The grid 2015 is supported by 2011. The diameter and height of the bottom of the micropoint 2013 are about 2 μm, and the opening diameter of the grid 2015 is also about 2 μm.
m. The face plate 2003 is the glass plate 20.
And a phosphor 2032 applied to the inner surface of 31 and the phosphor 20.
The conductive film 2033 covers 32 and acts as an accelerating electrode to which a voltage for accelerating the electrons emitted from the micropoints 2013 is applied.

In the above structure, the micropoint 20
The distance between the tip of the grid 13 and the grid 2015 is very small (1 μm or less), and since the tip of the micropoint 2013 is a protrusion, the micropoint 20
13 and grid 2015, a strong electric field (10 ⁷ V / cm or more) capable of field electron emission even with a potential difference of 100 V or less.
Can be formed. Although the amount of electron emission from one micropoint 2013 is about several μA, it is possible to form tens of thousands of micropoints 2013 per square mm. An electron-emitting device corresponding to one pixel is configured by a set of tens of thousands of micropoints 2013. Therefore,
An electron emission amount of several mA or more can be obtained per electron-emitting device corresponding to one pixel.

The potential applied to the grid 2015 and the micropoint 2013 is, for example, the grid 201.
The ground potential (0V) is applied to 5 and the micropoint 20
Electrons can be emitted to 13 by applying a negative potential (about −100 V) through the conductor 2012. further,
When a potential equal to or higher than that of the grid 2015 is applied to the face plate 2003 through the conductive film 2033, the electrons emitted from the electron source 2001 collide with the phosphor 2032 and excite the phosphor to emit light.

In order to control this light emitting point, a conductor 20 to which a plurality of micropoints 2013 are electrically connected
A plurality of row wirings 2041 formed by arranging 12 in a strip shape in the X direction and a column wiring 2042 to which the grid 2015 is electrically connected in the Y direction are provided, and are formed at the intersections of the matrix-shaped wiring patterns. Multiple electron-emitting device regions 2
In the desired area of 010, external power sources 2043, 204
4, matrix addressing is performed so that a voltage equal to or higher than a desired electron emission start voltage is applied, and a position where electrons are irradiated to the phosphor 2032 to which a voltage is applied from the acceleration voltage application power source 2045 through the conductive film 2033 is selected. By doing so, the image can be displayed. On the other hand, as an example of the MIM type, CAMead, "Operation of Tunnel-emiss
ion Devices ", J.Appl.Phys., 32, 646 (1961) and the like are known.

As an example of the surface conduction electron-emitting device, M.
I. Elinson, Radio Eng. Electron Phys., 10, (1965). The surface conduction electron-emitting device utilizes a phenomenon in which electron emission occurs when a current is applied to a thin film having a small area formed on a substrate in parallel with the film surface. As the surface conduction electron-emitting device, one using a SnO ₂ thin film by Erinson et al., One using an Au thin film [G. Dittmer: "Thin Solid Films", 9, 317 (1972)], I
n ₂ O ₃ / SnO ₂ thin film [M. Hartwell and C.G.
Fonstad: "IEEE Trans. ED Conf.", 519 (1975)], a carbon thin film [Hisashi Araki et al .: Vacuum, Vol. 26, No. 1, page 22 (1983)] and the like are reported.

As a typical example of the device configuration of these surface conduction electron-emitting devices, the above-mentioned M. A plan view of the device by Hartwell et al. Is shown in FIG. 30 in the figure
Reference numeral 01 is a substrate, and 3004 is a conductive thin film made of a metal oxide formed by sputtering. The conductive thin film 3004 is formed in an H-shaped planar shape as shown. An electron emission portion 3005 is formed by performing an energization process called energization forming described later on the conductive thin film 3004. The interval L in the figure is 0.5 to 1 mm, and W is 0.1.
It is set in mm. For convenience of illustration, the electron-emitting portion 305 is shown as a rectangular shape in the center of the conductive thin film 3004, but this is a schematic one, and the actual position and shape of the electron-emitting portion are faithfully represented. I'm not.

M. In the above-mentioned surface conduction electron-emitting device including the device by Hartwell et al., The conductive thin film 3004 is subjected to an energization treatment called energization forming before the electron emission, so that the dendritic emission part 3 is formed.
It was common to form 005. That is, the energization forming is performed by applying a constant direct current or a direct current that is boosted at a very slow rate of, for example, about 1 V / min to both ends of the conductive thin film 3004 to energize the conductive thin film 3004. Is locally destroyed or deformed or altered to form an electron emitting portion 3005 having a high electrical resistance. Note that a crack is generated in a part of the conductive thin film 3004 that is locally broken, deformed, or altered. When an appropriate voltage is applied to the conductive thin film 3004 after the energization forming, electron emission is performed in the vicinity of the crack.

Since the cold cathode electron source described above can be formed by using a technique such as photolithography or etching, it is possible to arrange a large number of elements at minute intervals. Moreover, as compared with the thermionic source, the cathode and the peripheral portion can be driven in a relatively low temperature state, so that a multi-electron beam generating source with a finer array pitch can be easily realized. Among such cold cathode electron sources, the surface conduction electron-emitting device is particularly desired in recent years because it has a simple device structure, is easy to manufacture, and has a large area. It is suitable as an electron-emitting device used in a large-screen image forming apparatus.

For example, as an image forming apparatus using this type of electron-emitting device, an electron source provided with the electron-emitting device and an image-forming member provided with a phosphor or the like that emits light upon collision of electrons are used as a supporting frame. It is known that the inside of an envelope constituted by the electron source, the image forming member and the support frame is placed in a vacuum so as to be opposed to each other with a vacuum. Further, the image forming member is provided with an accelerating electrode for accelerating the electrons emitted from the electron source toward the image forming member, and by applying a high voltage to the accelerating electrode, the emitted electrons are directed to the image forming member. Are accelerated and collide with the image forming member. Therefore, the support frame is made of an insulating material that can withstand high voltage.

[0019]

As described above, the conventional image forming apparatus utilizes the phenomenon that the electrons emitted from the electron source collide with the phosphor of the image forming member to emit light. Positive ions are generated by the reaction when electrons collide with the image forming member and by ionizing the atmospheric gas inside the apparatus. The positive ions are accelerated by the acceleration electrode in the direction opposite to the electrons emitted from the electron source by the electric field generated between the electron source and the image forming member, and reach the electron source. On the other hand, the electron source has many insulating portions necessary for patterning the device electrode of the electron-emitting device. Therefore, when the positive ions that reach the electron source are charged in the insulating portion of the electron source, the electrons emitted from the electron-emitting device are bent in the direction of the charged insulating portion, and their orbits are displaced, causing a problem such as displacement of the light emitting position. Occurs. In addition, the probability that discharge or the like is caused by the charged electric charge is increased, and the reliability and life of the device are impaired. In order to prevent the charging of the electron source, it is possible to cover the insulating part of the electron source with a conductive material to regulate the potential, but at least to what extent the conductive material should be covered to prevent the charging of the electron source. It was not clear as to whether it could be done. If the insulating portion of the electron source is entirely covered with a conductive material, the electron source can be reliably prevented from being charged, but it is useless to cover the electron source more than necessary.

The applicant of the present invention, as a method of realizing an image forming apparatus using a surface conduction electron-emitting device with a simpler structure, uses a plurality of row-direction wirings and a plurality of column-direction wirings to form a surface conduction type electron-emitting device. By connecting a pair of opposing device electrodes of the electron-emitting device, a simple matrix type electron source in which a large number of surface-conduction type electron-emitting devices are arranged in a matrix is formed. We are considering a system in which a large number of surface conduction electron-emitting devices can be selected and an electron emission amount can be controlled by giving an appropriate drive signal. Even in such a simple matrix type image forming apparatus using the surface conduction electron-emitting device, the surface of the insulating member may be similarly charged and the electron trajectory may be affected. The above-mentioned problem that the orbits of electrons deviate also occurs in an electron beam generator that does not use a phosphor as an electron-irradiated member, as in the image forming apparatus.

Therefore, an object of the present invention is to provide an electron beam generator and an image forming apparatus which reliably prevent the electron source from being charged by defining the potential in a minimum range and stabilize the emission electron trajectory. .

[0022]

In order to achieve the above object, an electron beam generator according to the present invention includes an electron source provided with an electron-emitting device and an electron source for irradiating electrons emitted from the electron-emitting device. An electron beam generator having an electron-irradiated member provided opposite to an electron source in a vacuum atmosphere and provided with an acceleration electrode for accelerating electrons emitted from the electron-emitting device, wherein the electron-irradiated member is When the angle with respect to the direction perpendicular to the surface of the electron-irradiated member is θ when viewed from the position where electrons emitted from the electron-emitting device are irradiated, the potential is defined within a range that satisfies tan θ ≦ 2. It is characterized by the presence of an electric potential regulating section.

The potential regulating portion has a surface resistance of 1 × 10 ^{5 with} respect to an area of 50% or more of the total surface area.
It may be composed of a conductor having a resistance of Ω / □ or less and having a surface resistance of 1 × 10 ¹² Ω / □ or less for the remaining area.

When the distance from the electron-irradiated member to the potential defining portion is d, the potential defining portion is parallel to the surface of the electron source from a position facing the position where the electron is irradiated. However, the potential regulating portion may be present within the range of at least 2d in any direction, and in this case, the electron emitting element and its electric wiring on the surface of the electron source are excluded. A potential regulating film is formed on the part, and the potential regulating portion is constituted by the electron emitting element and its electric wiring and the potential regulating film, or between the electron source and the electron irradiated member. A conductive plate having a surface resistance of 1 × 10 ⁵ Ω / □ or less, in which an electron passage hole through which electrons emitted from the electron-emitting device can pass, is arranged, and the electron-emitting device and its electrical wiring,
The potential regulating section may be configured with the conductive plate.

Further, a potential regulating film is formed on a portion of the surface of the electron source excluding the electron-emitting device and its electric wiring, and a wall extending toward the electron-irradiated member is formed on the outer periphery of the electron source. A striped electrode is formed, and the potential defining portion is configured by the electron-emitting device and its electrical wiring, the potential defining film, and the wall electrode.

Further, the electron-emitting device may be a cold cathode type electron-emitting device, and in particular, a surface conduction type electron-emitting device may be used.

In this case, a plurality of the surface conduction electron-emitting devices are arranged in a two-dimensional matrix, and each surface conduction electron-emitting device is composed of a plurality of row-direction wirings and a plurality of column-direction wirings. , May be connected to each other.

The image forming apparatus of the present invention uses the electron beam generating apparatus of the present invention, and instead of the electron-irradiated member, is arranged to face the electron source, and electrons emitted from the electron-emitting device collide. Thus, the image forming member is provided with a phosphor that emits light and an accelerating electrode for accelerating electrons emitted from the electron-emitting device.

In the electron beam generator of the present invention configured as described above, when electrons are emitted from the electron-emitting device of the electron source and irradiated on the electron-irradiated member, positive ions are generated from the electron-irradiated member. To do. The positive ions are accelerated in the direction opposite to the electrons emitted from the electron-emitting device, that is, toward the electron source due to the potential difference generated between the electron source and the electron-irradiated member by applying a voltage to the acceleration electrode. It At this time, the positive ions satisfy tan θ ≦ 2, where θ is the angle with respect to the direction perpendicular to the surface of the electron-irradiated member when viewed from the position where the electrons emitted from the electron-emitting member of the electron-irradiated member are irradiated. Attaches to members within range.
Therefore, by providing a potential regulating section that regulates the potential within the above range, positive ions are not charged in the electron source, and the trajectory of electrons emitted from the electron-emitting device is stabilized.

At this time, when it is impossible to form the entire potential regulating portion with a conductor having a low resistance value, the surface resistance is 1 × for an area of 50% or more of the total surface area of the potential regulating portion. It is sufficient to prevent charging of the electron source by using a conductor having a resistance of 10 ⁵ Ω / □ or less and a surface resistance of 1 × 10 ¹² Ω / □ or less for the remaining area.

Further, in the case where the potential regulating section is flat, when the distance from the electron-irradiated member to the potential regulating section is d, from the position of the potential regulating section facing the electron irradiation position, If the potential regulating portion is provided within at least 2d in any direction parallel to the plane of the electron source, the above t
The range of an θ ≦ 2 is satisfied. In this case, for example, the potential defining portion can be formed on the electron source, or the potential defining portion can be formed between the electron source and the electron-irradiated member.

Further, a wall-shaped electrode extending toward the electron-irradiated member is formed on the outer periphery of the electron source, and the wall-shaped electrode constitutes a part of the potential regulating portion, whereby the size of the electron source is t.
Even if it is smaller than the range satisfying an θ ≦ 2, the potential is defined by the wall electrode in the range exceeding this. As a result, the size of the electron source can be small, and a smaller electron beam generation device can be configured with the same size of the electron irradiation target member.

In the present invention, a plurality of surface conduction electron-emitting devices are arranged in a matrix by connecting the surface conduction electron-emitting devices with a plurality of row-direction wirings and a plurality of column-direction wirings. It is suitable for an electron beam generator using the above simple matrix type electron source. The simple matrix electron source can select a large number of surface conduction electron-emitting devices and control the electron emission amount by applying appropriate drive signals in the row direction and the column direction. It is not necessary to add a control electrode and can be easily constructed on one substrate.

Of course, in the present invention, even when some additional structure (for example, a focusing electrode, a deflection electrode, etc.) is provided between the electron source and the electron-irradiated member, the above concept is applied to each space between the additional structures. The same effect can be obtained by applying it and determining the configuration of the plurality of electrodes provided on the support member. Furthermore, it can be applied to the case where the additional structure also serves as a part of the plurality of electrodes.

In the image forming apparatus of the present invention, instead of the electron-irradiated member used in the electron beam generator of the present invention, light emitted by collision of electrons emitted from the electron-emitting device, which is arranged facing the electron source. Since the image forming member provided with the accelerating electrode for accelerating the electrons emitted from the phosphor and the electron-emitting device is used, the orbit of the electrons emitted from the electron-emitting device is stabilized as described above, and As a result, a good image is formed with no deviation in the light emitting position.

[0036]

Next, the present invention will be described with reference to the drawings.

(First Embodiment) FIG. 1 is a partially broken perspective view of a first embodiment of an image forming apparatus to which the electron beam generator of the present invention is applied, and FIG. 2 is shown in FIG. It is the figure which showed typically the cross section which looked at the image forming apparatus from the Y direction.

In FIG. 1, a rear plate 2 is fixed with an electron source 1 in which a plurality of surface conduction electron-emitting devices 15 are arranged in a matrix. In the electron source 1, a face plate 3 as an image forming member, in which a fluorescent film 7 and a metal back 8 as an accelerating electrode are formed on the inner surface of a glass substrate 6, is opposed via a supporting frame 4 made of an insulating material. It is arranged, and between the electron source 1 and the metal back 8,
A high voltage is applied by a power source (not shown). The rear plate 2, the support frame 4, and the face plate 3 are sealed to each other with frit glass or the like, and the rear plate 2, the support frame 4, and the face plate 3 form an envelope 10.

Further, on the surface of the electron source 1, SnO ₂ is provided in a predetermined range (a range shown by a broken line in FIG. 1) in a portion excluding each electron-emitting device 15 and a wiring electrically connecting them.
A potential defining film made of a film is formed, and the potential defining portion 9 is within this range.

As shown in FIG. 2, the potential regulating section 9 sets the distance between the metal back 8 and the electron source 1 to d, and the electrons emitted from each electron-emitting device 15 on the metal back 8 are actually emitted. When the maximum irradiation area is A, a perpendicular is drawn from the outermost contour of this area A toward the electron source 1,
It is located in the region B which is larger than the region surrounded by the perpendicular line by 2d in any direction parallel to the surface of the electron source 1. That is, the lengths in the X direction and the Y direction of the region C shown in FIG. 2 (the regions A, B, and C are shown as line segments in the X direction in FIG. 2, but the same applies to the Y direction). Saga 2
That is d. In other words, when viewed from the position of the metal back 8 where electrons emitted from the electron-emitting device 15 are actually irradiated, when the angle with respect to the direction perpendicular to the surface of the electron source 1 is θ, tan θ ≦ 2 The potential defining portion 9 exists in the range that satisfies the above condition. In this embodiment,
The distance d between the electron source 1 and the metal back 8 was set to 5 mm.

The above-mentioned components will be described in detail below.

(1) Electron Source 1 FIG. 3 is a plan view of an essential part of the electron source of the image forming apparatus shown in FIG. 1, and FIG. 4 is a sectional view of the electron source shown in FIG. It is a figure.

As shown in FIGS. 3 and 4, on the insulating substrate 11 made of a glass substrate or the like, m X-direction wirings 12 are provided.
And the n Y-direction wirings 13 are electrically separated by the interlayer insulating layer 14 and wired in a matrix. Surface conduction electron-emitting devices 15 are electrically connected between each X-direction wiring 12 and each Y-direction wiring 13.
Each electron-emitting device 15 includes a pair of device electrodes 16 and 17 arranged in the X direction with a space therebetween, and each device electrode 1
6 and 17, and one of the pair of device electrodes 16 and 17 is formed through the contact hole 14a formed in the interlayer insulating layer 14, It is electrically connected to the directional wiring 12, and the other element electrode 17 is electrically connected to the Y-directional wiring 13. Each of the device electrodes 16 and 17 is made of a conductive metal or the like, and is formed by a vacuum deposition method, a printing method, a sputtering method or the like.

The size and thickness of the insulating substrate 11 depend on the number of the electron-emitting devices 15 installed on the insulating substrate 11 and the design shape of each device, and a part of the container when the electron source 1 is used. When configured, it is appropriately set depending on the conditions and the like for holding the container in vacuum.

Each X-direction wiring 12 and each Y-direction wiring 13
Are made of a conductive metal or the like formed in a desired pattern on the insulating substrate 11 by a vacuum deposition method, a printing method, a sputtering method, or the like, and a voltage that is as uniform as possible is supplied to a large number of electron-emitting devices 15. Thus, the material, the film thickness, and the wiring width are set. The interlayer insulating layer 14 is SiO ₂ or the like formed by a vacuum deposition method, a printing method, a sputtering method or the like, and is formed in a desired shape on the entire surface or a part of the insulating substrate 11 on which the X-direction wiring 12 is formed. Especially the X direction wiring 12
And withstand the potential difference at the intersection of the Y-direction wiring 13,
The film thickness, material, and manufacturing method are appropriately set.

Further, the X-direction wiring 12 is electrically connected to a scan signal generating means (not shown) for applying a scan signal for arbitrarily scanning a row of electron-emitting devices 15 arranged in the X-direction. ing. On the other hand, the Y-direction wiring 13 is electrically connected to a modulation signal generating means (not shown) for applying a modulation signal for arbitrarily modulating each column of the electron-emitting devices 15 arranged in the Y direction. . Here, the drive voltage applied to each electron-emitting device 15 is supplied as a difference voltage between the scanning signal and the modulation signal applied to the device.

Here, an example of a method of manufacturing the electron source 1 will be specifically described in the order of steps with reference to FIG. The following steps a to h correspond to (a) to (h) in FIG.

Step a: Cr having a thickness of 50 Å and 6000 Å having a thickness of 6000 Å on the insulating substrate 11 in which a silicon oxide film having a thickness of 0.5 μm is formed on the cleaned soda-lime glass by a sputtering method. After sequentially stacking Au, a photoresist (AZ1370 Hoechst) was spin-coated with a spinner and baked,
The photomask image is exposed and developed to form a resist pattern for the X-direction wiring 12, and the Au / Cr deposited film is wet-etched to form the X-direction wiring 12 having a desired shape.

Step b: Next, an interlayer insulating layer 14 made of a silicon oxide film having a thickness of 0.1 μm is deposited by the RF sputtering method.

Step c: A photoresist pattern for forming the contact hole 14a is formed in the silicon oxide film deposited in the step b, and using this as a mask, the interlayer insulating layer 14 is formed.
Is etched to form a contact hole 14a.
The etching is performed by RIE (Rea) using CF ₄ H ₂ and gas.
ctive Ion Etching) method.

Step d: After that, a pattern to be the gap between the device electrodes and the device electrodes is formed into a photoresist (RD-20).
00N-41 manufactured by Hitachi Chemical Co., Ltd.), and Ti having a thickness of 50 Å and Ni having a thickness of 1000 Å were sequentially deposited by a vacuum vapor deposition method. A device electrode 1 in which the photoresist pattern is dissolved in an organic solvent, the Ni / Ti deposition film is lifted off, and the device electrode spacing L1 (see FIG. 3) is 3 μm and the device electrode width W1 (see FIG. 3) is 300 μm.
6 and 17 are formed.

Step e: After forming a photoresist pattern of the Y-direction wiring 13 on the device electrodes 16 and 17, a thickness of 5 is obtained.
Ti of 0 angstrom and Au of 5000 angstrom in thickness are sequentially deposited by vacuum evaporation, and an unnecessary portion is removed by lift-off, and a Y-direction wiring having a desired shape 1
Form 3

Step f: As shown in FIG. 6, a pair of device electrodes 16 and 17 which are spaced apart by the device electrode interval L1.
Using a mask 20 having an opening 20a crossing over, a Cr film 21 having a film thickness of 1000 angstrom is deposited and patterned by vacuum evaporation, and an organic Pd (ccp
4230 was manufactured by Okuno Seiyaku Co., Ltd. using a spinner and spin-coated, and heated and baked at 300 ° C. for 10 minutes.

The film thickness of the electron emission portion forming thin film 18 made of fine particles containing Pd as a main element thus formed is about 100 Å, and the sheet resistance value is 5 × 10 ^4.
Ω / □. In addition, the fine particle film described here is a film in which a plurality of fine particles are aggregated, and as a fine structure thereof,
Not only the state where the fine particles are individually dispersed and arranged, but also refers to a film in which the fine particles are adjacent to each other or overlap each other (including an island shape), and the particle size is a fine particle whose particle shape can be recognized in the above state. About the diameter.

Step g: Cr film 21 by acid enchantment
Then, the thin film 18 for forming an electron emission portion having a desired pattern shape was formed.

Step h: A pattern is formed such that a resist is applied to the portion other than the contact hole 14a portion, and Ti having a thickness of 50 Å and a thickness of 500 is formed by vacuum evaporation.
Au of 0 angstrom was sequentially deposited. Contact holes 14a were filled by removing unnecessary portions by lift-off.

Through the above steps, the X-direction wiring 12, the Y-direction wiring 13, and the electron-emitting device 15 are two-dimensionally formed and arranged on the insulating substrate 11 at equal intervals.

After that, the surface resistance of the portion where the interlayer insulating layer 14 is exposed, that is, the portion which is not covered with the X-direction wiring 12, the Y-direction wiring 13, the device electrodes 16 and 17, and the electron emission portion forming thin film 18. The SnO ₂ film (potential regulating film) is mask-patterned and vapor-deposited by an ion plating method so that the value becomes about 1 × 10 ¹¹ Ω / □, and the X-direction wiring 12, the Y-direction wiring 13, the element electrode 16, The potential defining portion 9 was composed of 17, the electron emission portion forming thin film 18, and the potential defining film. The film thickness of the potential regulating film was 1000 angstrom. In addition, the size of the potential defining portion 9 is the electron source 1
The distance d between the metal back 8 and the metal back 8 (see FIG. 2) is 5 mm.
Then, based on the experimental result that the electrons emitted from the electron emitting portion 23 (see FIG. 4) deviate by about 1 mm with respect to the direction perpendicular to the surface of the electron source 1 under the driving condition described later, The electron-emitting portion 23 was made larger by 11 mm in each of the X and Y directions.

The electron source 1 thus manufactured is fixed to the rear plate 2 by frit glass and housed inside the envelope 10, and the envelope 10 is turned into a vacuum pump through an exhaust pipe (not shown). After evacuation to reach a sufficient degree of vacuum, the device electrodes 16 of the electron emission device 15 are passed through the terminals Dox1 to Doxm and Doy1 to Doyn outside the container.
A voltage is applied between the electrodes 17 to energize (form) the electron emission portion forming thin film 18, so that the electron emission portion forming thin film 18 is locally broken and the electron emission portion forming thin film 18 is formed. 23 (see FIG. 4) are formed. For example, as the forming process, a triangular wave having a pulse width T ₁ of 1 msec and a peak value (peak voltage during forming) of 5 V as shown in FIG. 7 for 10 msec in a vacuum atmosphere of 10 ⁻⁶ Torr is used. By energizing the device electrodes 16 and 17 for 60 seconds at the pulse interval T ₂ , the electron emitting portion forming thin film 18 is locally destroyed, and the electron emitting portion 23 can be formed in the electron emitting portion forming thin film 18.

The electron-emitting portion 23 formed in this way
Was in a state in which fine particles containing a palladium element as a main component were dispersed and arranged, and the average particle diameter of the fine particles was 30 Å.

(2) Fluorescent Film 7 The fluorescent film 7 is composed of only phosphors in the case of monochrome, but in the case of color, it is called a black stripe or a black matrix depending on the arrangement of the phosphors as shown in FIG. It is composed of a black conductive material 7b and a phosphor 7a. Since the phosphor 7a needs to be arranged corresponding to the electron-emitting device 15, when the envelope 10 is configured, the face plate 3 and the rear plate 2 must be accurately aligned. The purpose of providing the black stripes and the black matrix is to make the color mixture of the three primary color phosphors, which is necessary in the case of color display, different from each other by making the color-separated portions between the respective phosphors 7a black so as to make the color mixture inconspicuous. This is to suppress a decrease in contrast due to light reflection. As the material of the black conductive material 7b, not only a material that is often used as a main component of graphite but also a material that is conductive and has little light transmission and reflection can be applied. The method of applying the phosphor 7a to the glass substrate 6 may be a precipitation method or a printing method regardless of monochrome or color.

(3) Metal Back 8 The purpose of the metal back 8 is to improve the brightness by specularly reflecting the light to the inner surface side of the fluorescent light of the phosphor 7a to the face plate 3 side, and to increase the electron beam acceleration voltage. Acting as an accelerating electrode for applying the phosphor 7 from damage caused by collision of negative ions generated in the envelope 10.
protection of a. The metal back 8 can be manufactured by performing a smoothing process (usually called filming) on the inner surface of the fluorescent film 7 after manufacturing the fluorescent film 7, and then depositing Al by vacuum evaporation or the like. On the face plate 3, a transparent electrode (not shown) such as ITO may be provided between the fluorescent film 7 and the glass substrate 6 in order to further enhance the conductivity of the fluorescent film 7.

(4) Envelope 10 The envelope 10 is connected to an exhaust pipe (not shown) and has a pressure of 10 ^-6 Torr.
After the degree of vacuum is made, it is sealed. Therefore, the rear plate 2, the face plate 3, and the support frame 4 forming the envelope 10 can withstand the atmospheric pressure applied to the envelope 10 and maintain a vacuum atmosphere, and the electron source 1 and the metal back 8 can be maintained.
It is desirable to use a material having an insulation property that can withstand a high voltage applied between them. Examples of the material include quartz glass, glass with a reduced content of impurities such as Na,
Examples include soda lime glass and ceramic members such as alumina. However, it is necessary to use the face plate 3 having a certain transmittance or more for visible light. Further, it is preferable to combine members having thermal expansion coefficients close to each other.

For sealing the face plate 3 and the support frame 4 with frit glass, and the rear plate 2 and the support frame 4 with frit glass, frit glass is applied to the respective joints and exposed to air. Alternatively, it was performed by firing at 400 to 500 ° C. for 10 minutes or more in a nitrogen atmosphere.

On the other hand, since the rear plate 2 is provided mainly for the purpose of reinforcing the strength of the electron source 1, if the electron source 1 itself has sufficient strength, the rear plate 2 is unnecessary and the electron source 1 Alternatively, the support frame 4 may be directly sealed to the envelope 10, and the electron source 1, the support frame 4, and the face plate 3 may constitute the envelope 10.

Further, a getter process may be performed in order to maintain the degree of vacuum after the envelope 10 is sealed. this is,
Immediately before or after sealing the envelope 10, a getter arranged at a predetermined position (not shown) in the envelope 10 is heated by resistance heating or high frequency heating to form a vapor deposition film. Processing. The getter usually has Ba as a main component, and due to the adsorption action of the deposited film, for example, 1 × 10 ⁻⁵
A vacuum degree of 1 × 10 ⁻⁷ Torr is maintained.

Next, the operation of this embodiment will be described.

Each electron-emitting device 15 has a terminal Dox outside the container.
When a voltage is applied through 1 to Doxm and Doy 1 to Doyn, electrons are emitted from the electron emitting portion 23. At the same time, a high voltage of 5 kV is applied to the metal back 8 (or a transparent electrode (not shown)) through the high voltage terminal H _V to accelerate the electrons emitted from the electron emitting portion 23 and collide with the inner surface of the face plate 3. As a result, the phosphor 7a (see FIG. 8) of the phosphor film 7 is excited and emits light, and an image is displayed.

By the way, the electrons emitted from the electron-emitting device 15 are directed in the direction parallel to the surface of the electron source 1, specifically, on the positive electrode side of the device electrodes 16 and 17 (see FIG. 3) of the electron-emitting device 15. Has an initial velocity in the direction. Therefore, the electrons emitted from the electron-emitting device 15 fly in a parabolic trajectory by being accelerated, and fly on the metal back 8 with respect to the normal line to the surface of the electron source 1 extending from the electron-emitting portion 23. It collides with a position displaced by about 1 mm.

As described above, the fluorescent substance 7a emits light when it is emitted from the electron emitting portion 23 but collides with the inner surface of the face plate 3. In addition to this light emission phenomenon, the fluorescent substance 7a adheres to the fluorescent film 7 and the metal back 8. A phenomenon occurs in which particles are ionized and scattered. Among the scattering particles, positive ions are accelerated toward the electron source 1 side by the voltage applied to the metal back 8 and fly in a parabolic orbit according to the initial velocity in the direction perpendicular to the electric field.

Here, assuming that the potential difference between the electron source 1 and the metal back 8 is Va and the maximum initial kinetic energy of the positive ions in the horizontal direction is eVi (electron volt; e is a unit charge amount), the metal back The moving distance ΔS in the direction parallel to the surface of the electron source 1 before the positive ions generated on the surface of 8 reach the electron source 1 which is separated by the distance d is 0 when the initial velocity of the positive ions in the vertical direction is 0. Then, ΔS = 2d × √ (eVi / Va) (1) In this embodiment, the total thickness of the metal back 8 and the phosphor 7 is about 50 μm or less, so the distance d between the electron source 1 and the metal back 8 is set to the insulating substrate 11 and the glass substrate 6. There is no problem in practical use as the distance.

If the positive ions generated on the surface of the metal back 8 receive all the energy due to the voltage applied to the metal back 8 and jump out in the direction horizontal to the surface of the electron source 1, the positive ions are generated. The moving distance ΔS to reach the electron source 1 becomes 2d by substituting Va for Vi in the equation (1). That is, a perpendicular line to the surface of the electron source 1 is extended from the position where the electron actually collides with the metal back 8, and a range of a radius 2d around the intersection of the perpendicular line with the electron source 1 on the inner surface of the electron source 1. Inside is a site where positive ions generated on the surface of the metal back 8 may reach. If this is expressed by an angle, the range in which positive ions may reach is a range that satisfies tan θ ≦ 2d / d = 2 (2).

Therefore, if the potential is defined at least within the range satisfying the formula (2), there is no potential indefinite surface in the flight direction of the positive ions generated on the surface of the metal back 8,
The electron source 1 will not be charged. In this embodiment, since the potential regulating section 9 is provided as described above, this potential regulating section 9 satisfies the expression (2). Of course, even if the size of the potential defining portion 9 is made larger than the above range,
The potential is regulated within the range that satisfies the expression (2), so there is no problem.

Further, the potential regulating film constituting the potential regulating section 9
Has a relatively high resistance value,
The ratio of the area of the position defining film is within 30%, and the other parts are
Cover with conductive material with sufficiently low resistance such as metal electrodes
Therefore, it is sufficient to define the electric potential. Sand
The potential regulating section 9 is entirely made of a conductive material having a low resistance value.
Need not be made, and one with low resistance value and one with high resistance value
You may comprise combining. In this case,
50% or more of the area has a surface resistance value of 1 x 10 ^Five Ω / □
It is composed of the following conductive materials, and the remaining part has a surface resistance value of 1 ×
10¹²It is preferable to use a conductive material having Ω / □ or less.

By providing the potential regulating portion 9 on the electron source 1 as described above, the inner surface of the face plate 3 is not charged, and the trajectory of the electrons emitted from the electron emitting element 15 is stabilized, A good image without displacement was obtained. In addition, the probability that discharge or the like is caused is extremely low, and a highly reliable image forming apparatus can be obtained.

Usually, a pair of device electrodes 1 of the electron-emitting device 15
The applied voltage between 6 and 17 is about 12 to 16 V, the distance d between the metal back 8 and the electron source 1 is about 2 mm to 8 mm, and the applied voltage Va of the metal back 8 is about 1 kV to 10 kV. In this embodiment, the applied voltage between the pair of device electrodes 16 and 17 is 14 V, the distance between the metal back 8 and the electron source 1 is 5 mm as described above, and the applied voltage Va of the metal back 8 is 5 mm.
kV.

(Second Embodiment) FIG. 9 is a partially broken perspective view of a second embodiment of the image forming apparatus of the present invention. In this embodiment, instead of forming a potential regulating film on the surface of the electron source 51, a metal conductive plate 55 is arranged on the electron source 51 via an insulating support column (not shown) having a thickness of about 100 μm. It is different from that of the first embodiment.

The metal conductive plate 55 is a metal plate having a thickness of about 100 μm, and has an electron passage hole 55a through which electrons emitted from a plurality of electron-emitting devices (not shown) provided in the electron source 51 can pass. , Formed corresponding to each electron-emitting device. The distance between the metal back 58 of the face plate 53 and the metal conductive plate 55 is 5 mm, and the size of the metal conductive plate 55 is set in the X direction and the Y direction from the electron emitting portion of the outermost electron emitting device. It was made large by 11 mm. An appropriate voltage is applied to the metal conductive plate 55 by an external power source (not shown) so as not to prevent collision of electrons from the electron-emitting device to the inner surface of the face plate 53.
This metal conductive plate 55 and the electrode of the electron-emitting device on the electron source constitute a potential regulating section. The other configurations and driving conditions are the same as those in the first embodiment, and the description thereof will be omitted.

As described above, even if the metal conductive plate 55 is arranged at a position separated from the electron source 51 and the metal conductive plate 55 constitutes a part of the potential regulating portion, the same effect as that of the first embodiment can be obtained. Obtainable.

(Third Embodiment) FIG. 10 is a schematic sectional view of a third embodiment of the image forming apparatus of the present invention.

In this embodiment, the wall-shaped electrode 105 extending toward the face plate 103 is provided on the outer periphery of the electron source 101.
In the first embodiment, the wall-shaped electrode 105 and the potential regulating film (not shown) formed on the electron source 101 electrically regulate the range satisfying the above-mentioned expression (2). Different from the one.

The wall-shaped electrode 105 is electrically connected to the element electrode of the electron-emitting device 115 or the potential regulating film of the electron source 101 to regulate the potential. The material of the wall-shaped electrode 105 is not particularly limited as long as it is a conductive material, but in this embodiment, 426 alloy having a thickness of 100 μm was used and fixed by frit glass. The other configurations and driving conditions are the same as those in the first embodiment, and the description thereof will be omitted.

By providing the wall-shaped electrode 105 as described above, the potential within which the positive ions generated in the metal back 108 can reach is defined by the electrons emitted from the electron-emitting device 115 colliding with the metal back 108. Since the electron source 101 is not charged, the trajectory of the electrons emitted from the electron-emitting device 115 is stable and a good image can be formed as in the first embodiment. Further, in the present embodiment, even if the size of the electron source 101 is smaller than that of the first embodiment, the electron source 1 is within the range satisfying the above-mentioned expression (2).
Since the potential is regulated by the wall-shaped electrode 105 in the range exceeding 01, the size of the electron source 101 can be reduced. As a result, it becomes possible to configure a smaller image forming apparatus with the same screen size.

In the above embodiments, the image forming apparatus of the present invention is applied to an image display apparatus, but the present invention is not limited to this range, and it is used as an image forming light emitting unit of an optical printer. It can be applied to a recording device by using it. In this case, as a normal form, an image forming unit arranged in a one-dimensional manner is often used. However, by appropriately selecting the above-mentioned m row-direction wirings and n column-direction wirings, it is possible to form a linear pattern. It can be applied not only as a light emitting source but also as a two-dimensional light emitting source.

Further, the object to be irradiated with electrons is not specified, and it can be applied as an electron beam generator forming a multi-plane electron source.

[0086]

Since the present invention is configured as described above, the following effects can be obtained.

In the electron beam generator of the present invention, when viewed from the position of the electron-irradiated member irradiated with the electrons emitted from the electron-emitting device, the angle with respect to the direction perpendicular to the surface of the electron-irradiated member is θ. At this time, since the potential is regulated by the potential regulating section within the range that satisfies tan θ ≦ 2, the electron emitted from the electron-emitting device is irradiated to the electron-irradiated member to the electron source of positive ions generated. Can be prevented from being charged. As a result, the trajectory of electrons emitted from the electron-emitting device can be stabilized.

At this time, even if it is impossible to form the entire potential regulating portion with a conductor having a low resistance value, the surface resistance is 50% or more of the total surface area of the potential regulating portion. Is composed of a conductor of 1 × 10 ⁵ Ω / □ or less,
If the remaining area is made of a conductor having a surface resistance of 1 × 10 ¹² Ω / □ or less, the electron source can be sufficiently prevented from being charged.

Further, in the case where the potential regulating portion is flat, when the distance from the electron-irradiated member to the potential regulating portion is d, from the position of the potential regulating portion facing the electron irradiation position, If the potential regulating portion is provided within at least 2d in any direction parallel to the plane of the electron source, the above t
The range of an θ ≦ 2 can be satisfied. In this case, for example, the potential defining portion can be formed on the electron source, or the potential defining portion can be formed between the electron source and the electron-irradiated member.

Further, a wall-shaped electrode extending toward the electron-irradiated member is formed on the outer periphery of the electron source, and the wall-shaped electrode constitutes a part of the potential regulating portion, thereby reducing the size of the electron source. Therefore, it is possible to configure a smaller electron beam generator with the same size of the electron irradiation target member.

By using the cold cathode type electron-emitting device as the electron-emitting device, it is possible to construct a large-sized electron beam generator which saves power and has a fast response speed. Among them, the surface conduction electron-emitting device has a simple device structure and a plurality of devices can be easily arranged. Therefore, by using the surface conduction electron-emitting device, the structure is simple and large. An electron beam generator can be achieved.

Furthermore, by arranging a plurality of surface conduction electron-emitting devices in a two-dimensional matrix and connecting them with a plurality of row-direction wirings and a plurality of column-direction wirings, respectively, the row-direction and column-direction wirings can be obtained. Since a large number of surface conduction electron-emitting devices can be selected and the amount of electron emission can be controlled by giving an appropriate driving signal in the direction, basically, it is not necessary to add another control electrode, and It can be easily constructed on a single substrate.

Since the image forming apparatus of the present invention uses the electron beam generating apparatus of the present invention, as described above, the orbits of electrons are stable, and it is possible to form a good image without deviation of the light emitting position. Become. In particular, by using the surface conduction electron-emitting device as the electron-emitting device, an image forming apparatus having a simple structure and a large screen can be achieved.

[Brief description of drawings]

FIG. 1 is a partially cutaway perspective view of a first embodiment of an image forming apparatus of the present invention.

FIG. 2 is a diagram schematically showing a cross section of the image forming apparatus shown in FIG. 1 viewed from a Y direction.

FIG. 3 is a plan view of a main part of an electron source of the image forming apparatus shown in FIG.

4 is a cross-sectional view of the electron source shown in FIG. 3 taken along the line AA '.

5A to 5C are diagrams sequentially showing a manufacturing process of the electron source of the image forming apparatus shown in FIG.

FIG. 6 is a plan view of an example of a mask used when forming a thin film for forming an electron emitting portion.

FIG. 7 is a diagram showing an example of a voltage waveform used in forming processing.

FIG. 8 is a diagram for explaining the configuration of a fluorescent film.

FIG. 9 is a partially cutaway perspective view of the second embodiment of the image forming apparatus of the present invention.

FIG. 10 is a schematic cross-sectional view of a third embodiment of the image forming apparatus of the invention.

FIG. 11 is a schematic configuration diagram of a conventional image forming apparatus using a thermoelectron source.

FIG. 12 is a schematic configuration diagram partially showing a conventional image forming apparatus using a field emission type electron source.

FIG. 13 is a diagram showing a typical device configuration of a surface conduction electron-emitting device.

[Explanation of symbols]

 1, 51, 101 Electron source 2 Rear plate 3, 53, 103 Face plate 4 Support frame 6 Glass substrate 7 Fluorescent film 7a Phosphor 8, 58, 108 Metal back 9 Potential regulating section 10 Envelope 11 Insulating substrate 12 X Directional wiring 13 Y-direction wiring 14 Interlayer insulating layer 14a Contact hole 15, 115 Electron emitting element 16, 17 Element electrode 18 Thin film for forming electron emitting portion 20 Mask 20a Opening 21 Cr film 23 Electron emitting portion 55 Metal conductive plate 55a Electron passing hole 105 wall electrode

Claims (10)

[Claims] 1. An electron source provided with an electron-emitting device, and said electron source are arranged to face each other in a vacuum atmosphere in order to irradiate electrons emitted from said electron-emitting device, and emitted from said electron-emitting device. In an electron beam generator having an electron-irradiated member having an accelerating electrode for accelerating electrons, the electron is emitted when viewed from a position where electrons emitted from the electron-emitting device of the electron-irradiated member are irradiated. When the angle with respect to the direction perpendicular to the surface of the irradiated member is θ, tan θ
An electron beam generator characterized in that a potential defining portion in which the potential is defined is present within a range that satisfies ≦ 2. 2. The potential regulating portion has a surface resistance of 1 × 10 ^{5 with} respect to an area of 50% or more of the total surface area.
The electron beam generator according to claim 1, wherein the electron beam generator is made of a conductor having a resistance of Ω / □ or less, and has a surface resistance of 1 × 10 ¹² Ω / □ or less in the remaining area. 3. When the distance from the electron-irradiated member to the potential defining portion is d, the potential defining portion is parallel to the surface of the electron source from a position facing the position where the electron is irradiated. The electron beam generator according to claim 1 or 2, wherein the potential defining portion is present within a range of at least 2d in any direction. 4. A potential regulating film is formed on a portion of the surface of the electron source excluding the electron emitting element and its electric wiring, and the potential regulating film is defined by the electron emitting element and its electric wiring and the potential regulating film. The electron beam generator according to claim 3, wherein a part is configured. 5. Between the electron source and the electron-irradiated member
The electrons emitted from the electron-emitting device can pass through
Surface resistance with electron passage holes is 1 x 10 ^FiveΩ / □ or less
The lower conductive plate is disposed, and the electron-emitting device and its
The potential defining portion is configured by the air wiring and the conductive plate.
The electron beam generator according to claim 3. 6. A potential regulating film is formed on a portion of the surface of the electron source excluding the electron-emitting device and its electric wiring, and a wall extending toward the electron-irradiated member is provided on the outer periphery of the electron source. 3. A potential-shaped electrode is formed, and the potential-defining portion is constituted by the electron-emitting device and its electrical wiring, the potential-defining film, and the wall-shaped electrode.
An electron beam generator according to claim 1. 7. The electron beam generator according to claim 1, wherein the electron-emitting device is a cold cathode type electron-emitting device. 8. The electron beam generator according to claim 7, wherein the cold cathode electron-emitting device is a surface conduction electron-emitting device. 9. A plurality of the surface conduction electron-emitting devices are arranged in a two-dimensional matrix, and each of the surface conduction electron-emitting devices is composed of a plurality of row-direction wirings and a plurality of column-direction wirings. The electron beam generator according to claim 8, wherein the electron beam generators are connected to each other. 10. An image forming apparatus using the electron beam generating apparatus according to claim 1, the image forming apparatus being arranged opposite to the electron source in place of the electron irradiation member. An image forming apparatus comprising an image forming member provided with a phosphor that emits light when electrons emitted from an electron emitting element collide with each other and an acceleration electrode for accelerating electrons emitted from the electron emitting element.