JP2001222945A - Device of manufacturing electron source circuit board, electron source circuit board, and image display device using the circuit board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture an electron emitting element applicable to an image display device highly accurately and at a low cost by using an ink-jet method. SOLUTION: The electron emitting elements, applicable to a display device to display images by making a fluorescent material emit visible light with electrons emitted by applying voltage, are manufactured by an ink-jet method. A jet head 11 is mounted on a carriage 12 movable in two orthogonally crossing directions, and a prescribed distance is kept between the head 11 and a circuit board 14. A liquid including a material of a conductive thin film a jetting out of the head 11, with the carried running, to be applied to a prescribed position on the circuit board 14, on which conductive electron emitting elements are formed. The angle of jetting the liquid can vary according to the structure of the device, while the distance between the circuit board 14 and the head is optimized according to the jetting angle.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for manufacturing an electron source substrate using a surface conduction electron-emitting device, an electron source substrate manufactured by the apparatus, and an image display apparatus using the same.

[0002]

2. Description of the Related Art Conventionally, two types of electron emitting devices, a thermionic electron source and a cold cathode electron source, are known. The cold cathode electron source includes a field emission type (hereinafter, referred to as an FE type), a metal / insulating layer / metal type (hereinafter, referred to as an MIM type), and a surface conduction type electron emission element. Examples of the FE type include “WP Dyke &
W. W. Dolan, "Fielddemion",
Advance in Electron Physi
cs, 889 (1956) "or" CA Sp.
indt, "Physical Properties
of thin-film field emiss
ion cathodes with mollybde
nium "J. Appl. Phys., 475248.
(1976) ". An example of the MIM type is “CA Mead,” The Tunnel-em.
issueampifier ", J. Appl. P
hys. , 32 646 (1961) "and the like.

As an example of a surface conduction electron-emitting device, see “MI Elinson, Radio Eng.
Electron Phys. , 1290 (196
5) "and the like. The surface conduction electron-emitting device utilizes a phenomenon in which an electron is emitted by passing a current through a small-area thin film formed on a substrate in parallel with the film surface. Examples of the surface conduction electron-emitting device include a device using an SnO ₂ thin film by Elinson et al. And a device using an Au thin film (“G. Dittmer:“ Thin Sol ”).
idFilms ", 9 317 (1972)"), In ₂
O ₃ / SnO ₂ thin film (“M. Hartwell”
and C.I. G. FIG. Fonstad: "IEEEtra
ns. ED Conf. ", 519 (1975)"),
By carbon thin film (“Hisashi Araki et al .: Vacuum, 26th
Vol. 1, No. 22, p. 22 (1983) ").

A typical device configuration of these surface conduction electron-emitting devices is described in the above-mentioned M.S. FIG. 14 shows an element configuration of Hartwell. In FIG. 14, 1 is a substrate, 2, 3
Denotes an element electrode, 4 denotes a conductive thin film, and 5 denotes an electron emitting portion.
The conductive thin film 4 is formed of a metal oxide thin film or the like formed by sputtering in an H-shaped pattern, and the electron emission portion 5 is formed by an energization process called energization forming described below. The device electrode interval L1 in the figure is 0.5 to 1 m.
m and W ′ are set to 0.1 mm.

Conventionally, in these surface-conduction electron-emitting devices, the electron-emitting portion 5 is generally formed by subjecting the conductive thin film 4 to an energization process called energization forming before performing electron emission. It is a target. In the energization forming, a direct current voltage or a very slowly increasing voltage of, for example, about 1 V / min is applied to both ends of the conductive thin film 4 and energized to locally destroy, deform or alter the conductive thin film 4. The purpose is to form the electron-emitting portion 5 in a state of high resistance. Note that the electron emission section 5
In, a crack is generated in a part of the conductive thin film 4, and electrons are emitted from the vicinity of the crack. The surface conduction electron-emitting device subjected to the energization forming treatment is a conductive thin film 4
Is applied, and a current is caused to flow through the element to cause the electron emission section 5 to emit electrons.

Since such a surface conduction electron-emitting device has a simple structure and is easy to manufacture, there is an advantage that a large number of devices can be arrayed over a large area. Therefore, applied researches on charged beam sources, display devices and the like utilizing this feature have been made. As an example in which a large number of surface conduction electron-emitting devices are arrayed, a surface conduction electron-emitting device called a ladder-type arrangement is arranged in parallel as described later, and both ends of each element are wired (common wiring is also used). ), And an electron source in which a number of connected lines are arranged in a large number of rows (for example,
JP-A-4-31332, JP-A-1-283737, JP-A-2-257552 and the like. In particular, in image forming apparatuses such as display apparatuses, flat panel display apparatuses using liquid crystal have been widely used in place of CRTs in recent years. However, since they are not self-luminous, they must be provided with a backlight. Therefore, development of a self-luminous display device has been desired. Examples of the self-luminous display device include an image forming device that is a display device in which an electron source having a large number of surface conduction emission devices arranged therein and a phosphor that emits visible light by electrons emitted from the electron source are combined. (For example, US Pat. No. 5,066,883).

However, the method of manufacturing a surface conduction electron-emitting device according to the above-mentioned conventional example makes heavy use of photolithography and etching in vacuum film formation and a semiconductor process.
There are disadvantages in that the number of steps is large and the production cost of the electron source substrate is high.

In order to solve such a problem, the present inventor, in forming a conductive thin film of the element portion of the surface conduction electron-emitting device, US Pat. No. 3,060,429 and US Pat.
No. 98030, U.S. Pat. No. 3,596,275, U.S. Pat. No. 3,416,153, U.S. Pat. No. 3,747,120, U.S. Pat. No. 5,729,257, and the like. Instead, it was thought that the conductive thin film could be formed stably with good yield and at low cost.

[0009] However, unlike ink jet recording in which recording is performed by flying so-called ink toward paper, it is still not enough to stably fly a solution containing an element or compound that becomes a conductive thin film and apply it on a substrate. There are many unresolved elements. In particular, great efforts are required to form a surface conduction electron-emitting device group on such an electron source substrate at a highly accurate position as in the prior art.

[0010]

SUMMARY OF THE INVENTION The present invention relates to an electron source substrate manufacturing apparatus for an image display device using the above-mentioned surface conduction electron-emitting device, an electron source substrate manufactured by the manufacturing apparatus, and an electron source substrate using the same. The purpose of the present invention is to provide a manufacturing apparatus for forming a group of surface conduction electron-emitting devices with high accuracy.

Another object of the present invention is to provide an electron source substrate manufactured by the above-described manufacturing apparatus and having a surface-conduction type emission element group formed with high precision. Still another object of the present invention is to provide a high-quality image display device using a high-accuracy electron source substrate manufactured by the above-described manufacturing apparatus.

[0012]

According to a first aspect of the present invention, there is provided a method of manufacturing an electron source substrate comprising a substrate and an electron emitting element group having a conductive thin film which emits electrons by applying a predetermined voltage. In the apparatus, a substrate holding unit having a holding / positioning unit or a holding position adjusting mechanism for the substrate, and a plurality of pairs provided on the substrate based on input droplet application information, disposed at a position facing the substrate. An ejection head for forming the conductive thin film by injecting a solution containing the material of the conductive thin film between the element electrodes; information input means for inputting the liquid droplet application information to the ejection head; A carriage mounted with a head and movable in two directions orthogonal to each other in a region facing the substrate, wherein the carriage has a shape of a solution ejection port surface of the ejection head and a conductive thin film of the substrate. It is obtained by and performing injection of the solution while scanning to maintain the surface at a constant distance.

According to a second aspect of the present invention, in the first aspect of the present invention, the substrate is held by the substrate holding means such that a conductive thin film forming surface of the substrate is horizontal, and the jet head is provided with the substrate. The solution is ejected downward at a position above the liquid crystal, and the predetermined distance is in a range of 0.1 mm to 10 mm.

According to a third aspect of the present invention, in the first aspect of the present invention, the substrate is held by the substrate holding means at an angle of greater than 0 ° and 90 ° or less with respect to the horizontal with respect to the horizontal surface on which the conductive thin film is formed. The jet head jets the solution from above or from the side of the substrate substantially perpendicularly to the conductive thin film forming surface of the substrate, and the predetermined distance is 0.1.
mm to 8 mm.

According to a fourth aspect of the present invention, in the first aspect of the present invention, the substrate is held at an angle of more than 90 degrees and less than 180 degrees with respect to horizontal by the substrate holding means. The jet head jets the solution substantially perpendicularly to the surface on which the conductive thin film is formed from the side or below the substrate, and the predetermined distance is 0.1 m.
It is characterized in that it is configured to be in the range of m to 6 mm.

According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the jetting speed of the solution is higher than the scanning speed of the carriage.

According to a sixth aspect of the present invention, there is provided an electron source substrate manufacturing apparatus according to any one of the first to fifth aspects.

According to a seventh aspect of the present invention, there is provided the electron source substrate according to the sixth aspect, and a phosphor which can be disposed to face the electron source substrate, wherein the electrons emitted by the electron source substrate are used as the phosphor. The display is performed by causing the phosphor to emit light by colliding with the light.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the present invention will be described. The basic configuration of the surface conduction electron-emitting device of the present invention is a planar type. FIG. 1 is a view showing an example of an electron source substrate formed by the manufacturing apparatus of the present invention. Here, for simplification, the configuration of one flat surface conduction electron-emitting device is schematically shown. I have. Actually, as will be described later, the flat surface conduction electron-emitting devices are formed as a group of devices arranged in a matrix. FIG. 1A is a plan view of a flat surface conduction electron-emitting device, and FIG.
In the figure, 1 is a substrate, 2 and 3 are device electrodes, 4 is a conductive thin film,
Reference numeral 5 denotes an electron emitting portion. As the substrate 1, quartz glass,
Glass with a reduced content of impurities such as Na, blue plate glass, a glass substrate having SiO ₂ deposited on the surface thereof, and a ceramic substrate such as alumina can be used. As a material for the device electrodes 2 and 3, a general conductive material can be used. For example, Ni, Cr, Au, Mo, W, P
metals or alloys such as t, Ti, Al, Cu, Pd;
d, As, Ag, Au, RuO 2, Pd-Ag or the like metal or metal oxide and printed conductor composed of glass or the like, In ₂ O ₃ -SnO ₂ a transparent conductive material such as, a semiconductor material such as polysilicon And so on.

The distance L between the device electrodes 2 and 3 is preferably in the range of several thousand to several hundred μm, and more preferably in the range of 1 to 100 μm in consideration of the voltage applied between the device electrodes 2 and 3. It is. The length W of the device electrodes 2 and 3 is several μm to several hundred μm in consideration of the resistance value and the electron emission characteristics of the electrodes.
The range is from 00 ° to 1 μm. In addition, the configuration is not limited to the configuration shown in FIG.
May be formed in order.

FIG. 2 is a diagram for explaining a method of manufacturing the flat surface conduction electron-emitting device having the structure shown in FIG. As the conductive thin film 4, in order to obtain good electron emission characteristics,
A fine particle film composed of fine particles is particularly preferable, and the film thickness is appropriately set according to step coverage to the device electrodes 2 and 3, a resistance value between the device electrodes 2 and 3, an energization forming condition described later, and the like. Is several to several thousand, particularly preferably 10 to 500. In addition, the resistance value of the conductive thin film 4 is such that Rs is 10 2 to 10 7 Ω. Note that Rs has a thickness t,
The resistance R of a thin film having a width of w and a length of 1 is calculated by R = Rs (1 /
w), Rs = ρ / t where ρ is the resistivity of the thin film material. Here, the forming process will be described using an energizing process as an example.
The forming process is not limited to this, and any method may be used as long as the film is cracked to form a high resistance state.

The material constituting the conductive thin film 4 is P
d, Pt, Ru, Ag, Au, Ti, In, Cu, C
metals such as r, Fe, Zn, Sn, Ta, W, Pb, Pd
Oxides such as O, SnO ₂ , In ₂ O ₃ , PbO, Sb ₂ O ₃ , HfB ₂ , ZrB ₂ , LaB ₆ , CeB ₆ , YB ₄ , G
borides such as dB ₄ , TiC, ZrC, HfC, TaC,
It is appropriately selected from carbides such as SiC and WC, nitrides such as TiN, ZrN and HfN, semiconductors such as Si and Ge, and carbon.

The fine particle film described here is a film in which a plurality of fine particles are gathered, and has a fine structure not only in a state where the fine particles are individually dispersed and arranged, but also when the fine particles are adjacent to each other.
Alternatively, they are in an overlapping state (including a case where some fine particles are aggregated to form an island shape as a whole). The particle size of the fine particles is from several degrees to 1 μm, preferably from 10 degrees to 200 degrees.

Hereinafter, an apparatus for manufacturing an electron source substrate on which a surface conduction electron-emitting device according to an embodiment of the present invention is formed will be described. FIG. 3 is a view for explaining an embodiment of the apparatus for manufacturing an electron source substrate according to the present invention. In the figure, reference numeral 11 denotes an ejection head unit (ejection head), 12 denotes a carriage, 13 denotes a substrate holding table, and 14 denotes A substrate for forming a group of planar surface conduction type electron-emitting devices, 15 is a supply tube for a solution containing a conductive thin film material, 16 is a signal supply cable, 17 is an ejection head control box, and 18 is an X of the carriage 12.
Direction scan motor, 19 is a Y direction scan motor of the carriage 12, 20 is a computer, 21 is a control box, and 22 (22 _X1 , 22 _{Y 1} , 22 _{X 2} , 22 _{Y 2} ).
Is a substrate positioning / holding means.

FIG. 4 is a schematic view showing the configuration of a droplet applying apparatus applied to the manufacture of an electron source substrate according to the present invention, and FIG. 5 is a schematic structural view of a main part of a discharge head unit of the droplet applying apparatus of FIG. It is. The configuration of FIG. 4 differs from the configuration of FIG. 3 in that the electron-emitting device group is formed on the substrate by moving the substrate 14 side. 4 and 5, 31 is a head alignment control mechanism, 32 is a detection optical system, 33 is an inkjet head, 34 is a head alignment fine movement mechanism, 35 is a control computer, 36 is an image identification mechanism, 38 is a position detection mechanism, 39 Is a position correction control mechanism, 40 is an inkjet head drive / control mechanism, 41 is an optical axis, 42 is an element electrode,
3 is a droplet, and 44 is a droplet landing position.

The droplet applying device (ink-jet head 33) of the discharge head unit 11 may be any mechanism as long as it can discharge a given amount of liquid droplets in particular. A mechanism is desirable. As the ink jet method, any of a piezo jet method using a piezoelectric element, a bubble jet method in which bubbles are generated using thermal energy of a heater, and a charge control method (continuous flow method) may be used.

In the present invention, in such an electron source substrate manufacturing apparatus (FIG. 3), the substrate 14 is determined by adjusting the holding position of the substrate 14 by the substrate positioning / holding means 22 of the apparatus. Although simplified in FIG. 3, the substrate positioning / holding means 22 is in contact with each side of the substrate 14 and X
In the direction and the Y direction perpendicular thereto, the fine adjustment can be performed in the order of μm, and is connected to the ejection head control box 17, the computer 20, the control box 21, and the like. The position information, timing, etc. of the drop application can be constantly fed back.

Further, the apparatus for manufacturing an electron source substrate according to the present invention has a rotation position adjustment mechanism (not shown because it is located below the substrate 14) in addition to the position adjustment mechanism in the X and Y directions. I have. In this regard, the shape of the electron source substrate and the arrangement of the formed electron-emitting devices will be described first.

As described above, the electron source substrate of the present invention includes quartz glass, glass having a reduced impurity content such as Na, blue plate glass, a glass substrate having SiO ₂ deposited on its surface, and a ceramic substrate such as alumina. Is used, and its shape is a rectangle (a quadrangle). In other words, the substrate has two vertical sides and two horizontal sides constituting the rectangular shape, the two vertical sides are parallel to each other, the horizontal two sides are parallel to each other, and the vertical and horizontal sides are at right angles.

According to the present invention, a group of electron-emitting devices to be formed is arranged in a matrix with respect to such a substrate, and two directions orthogonal to each other in the matrix correspond to a vertical side or a horizontal side of the substrate. The electron-emitting device groups are arranged so as to be parallel to the direction. The reason why the electron-emitting device groups are arranged in a matrix and the reason that the vertical and horizontal sides of the substrate are parallel to two orthogonal directions of the matrix will be described below.

As shown in FIG. 3 or FIG. 4, in the present invention, after the positional relationship between the substrate 14 and the solution ejection port surface of the ejection head unit 11 is determined first, no particular position control is performed. . That is, the ejection head unit 11 mounted on the carriage 12 ejects the solution containing the material of the conductive thin film while moving in the X and Y directions while keeping a certain distance with respect to the substrate 14. That is, the X direction and the Y direction are two directions that are orthogonal to each other. If the vertical side or the horizontal side of the substrate is set to be parallel to the Y direction or the X direction when positioning the substrate, the X direction and the Y direction are formed. Since the two electron-emitting device groups in the matrix arrangement are parallel to each other, a high-precision device group can be formed only by a mechanism for ejecting while moving the carriage. In other words, if the substrate shape as in the present invention, the matrix arrangement of the electron-emitting devices, and the carriage moving device in the two orthogonal X and Y directions are used, the positioning of the substrate before the droplet ejection for element formation is performed. This means that a high-precision matrix-like array of electron-emitting devices can be obtained.

Here, the description will return to the rotation position adjusting mechanism described above. As described above, in the present invention, the position of the substrate is accurately determined before the droplet ejection for element formation is performed, only the carriage movement in the X and Y directions is performed, and no other control is performed. It is intended to obtain a matrix-like arrangement of groups. In this case, a problem is a deviation of a rotation direction (a rotation direction with respect to an axis perpendicular to a plane determined by two directions of X and Y) when the substrate is first positioned.

In order to correct the deviation in the rotation direction, the present invention has a rotation position adjusting mechanism not shown (not visible below the substrate 14) as described above. Thus, when the deviation in the rotation direction is also corrected and the side of the substrate is positioned, the apparatus of the present invention can obtain a highly accurate matrix-like arrangement of the electron-emitting device groups by moving the carriage only in the X and Y directions.

The above description is based on the rotation position adjusting mechanism shown in FIG.
22 (22 _X1, 22_Y1, 2
2_X2, 22_Y2) Is described as a separate mechanism (substrate 1
4 and cannot be seen), but the substrate positioning / holding hand
It is also possible to provide the stage 22 with a rotational position adjusting mechanism.
You. For example, the substrate positioning / holding means 22
And the entire substrate positioning / holding means 22 is
Now you can adjust the position in the X or Y direction
But on the side of the substrate 14 of the substrate positioning / holding means 22
Two pieces provided at a distance in the abutting part
Angle can be adjusted if the screws are moved independently
It is. Note that this rotation position control information is also used in the X and Y directions described above.
Injection as well as orientation information and fine adjustment displacement information
Head control box 17, computer 20,
Connected to the control box 21 etc.
Position information, timing, etc. can be constantly fed back
It has become.

Next, another means and configuration of the positioning according to the present invention will be described. In the above description, the substrate positioning / holding means 22 is in contact with the side of the substrate 14 so that the position of the entire substrate positioning / holding means 22 can be adjusted in the X direction or the Y direction. A description will be given of an example in which a band-shaped pattern is provided not in the side of the substrate 14 but in two directions orthogonal to each other on the substrate. As described above, in the present invention, the electron-emitting device group is formed on the substrate by arranging it in a matrix. It is formed so as to be parallel to. Such a pattern can be easily formed on a substrate by a photofabrication technique.

Alternatively, the above-described pattern is not created only for the purpose, but is used for the device electrodes 2 and 3.
The wiring patterns such as the X-directional wiring 72 and the Y-directional wiring 73 in FIGS. 8 and 9 described later (FIGS. 1 and 2) may be regarded as two-directional strip patterns in the present invention. If such a band-shaped pattern is provided, a detection optical system 3 using a CCD camera and a lens as described later with reference to FIG.
2 enables pattern detection and feedback to position adjustment.

Next, in the Z direction, which is a direction perpendicular to the X and Y directions, in the present invention, after the positional relationship between the substrate 14 and the solution ejection port surface of the ejection head unit 11 is determined first. No particular position control is performed. In other words, the ejection head unit 11 ejects the solution containing the material of the conductive thin film while moving the carriage in the X and Y directions while maintaining a certain distance with respect to the substrate 14. The position control of the unit 11 in the Z direction is not particularly performed. The reason is that if the control is performed at the time of injection, not only the mechanism and control system become complicated, but also
This is because the formation of the conductive thin film by applying droplets to the substrate 14 is delayed, and the productivity is significantly reduced.

Instead, in the present invention, the flatness of the substrate 14, the flatness of the device holding the substrate 14, and the accuracy of a carriage mechanism for moving the ejection head unit 11 in the X and Y directions are improved. By doing so, the X-direction and Y-direction carriage movements of the ejection head unit 11 and the substrate 14 are performed at high speed without performing the Z-direction control at the time of ejection, thereby improving productivity. As an example, the variation in the distance between the substrate 14 and the solution ejection surface of the ejection head unit 11 when applying the solution of the present invention (during ejection) is suppressed to 5 mm or less (the size of the substrate 14 is 200 mm × 2).
00 mm or more and 4000 mm x 4000 mm or less).

Next, the configuration of the ejection head unit 11 will be described with reference to FIG. In FIG. 5, reference numeral 32 denotes a detection optical system that captures image information on the substrate 14, which is close to the inkjet head 33 that ejects the droplet 43,
The two optical axes 41 and the focal position are arranged so as to coincide with the landing position 44 of the droplet 43 by the inkjet head 33. In this case, the positional relationship between the detection optical system 32 and the inkjet head 33 shown in FIG.
Can be adjusted more precisely. The detection optical system 32 uses a CCD camera and a lens.

In FIG. 4, reference numeral 36 denotes the detection optical system 32.
Is an image identification mechanism for identifying the image information captured in step (1), and has a function of binarizing the contrast of the image and calculating the position of the center of gravity of the binarized specific contrast portion. Specifically, a high-precision image recognition device VX-4210 manufactured by KEYENCE CORPORATION can be used. A means for providing the obtained image information with position information on the electron source substrate 14 is a position detection mechanism 38. Also,
Based on the image information and the position information on the substrate 14,
The position correction is performed by the position correction control mechanism 39, which corrects the movement of the carriage scanning mechanism. In addition, the inkjet head control / drive mechanism 40
Accordingly, the inkjet head 33 is driven, and the droplet is applied on the substrate 14. The above-described control mechanisms are centrally controlled by the control computer 35.

As a material of the droplet 43, an aqueous solution, an organic solvent, or the like containing the above-described element or compound that becomes a conductive thin film can be used. For example, a palladium-based element or compound as a conductive thin film is shown below, and a palladium acetate-ethanolamine complex (PA-M
E), palladium acetate-diethanol complex (PA-D
E), palladium acetate-triethanolamine complex (P
A-TE), an aqueous solution containing an ethanolamine complex such as palladium acetate-butylethanolamine complex (PA-BE) and palladium acetate-dimethylethanolamine complex (PA-DME), and a palladium-glycine complex (Pd- Gly), an aqueous solution containing an amine acid complex such as a palladium-β-alanine complex (Pd-β-Ala) or a palladium-DL-alanine complex (pd-DL-Ala). A butylamine solution of a propylamine complex is exemplified.

The droplet 43 is discharged from the discharge head unit 1
When applying to a desired element electrode portion by 1, the position to be applied is measured by the detection optical system 32 and the image identification mechanism 36, and the measured data, the position of the discharge port surface of the discharge head unit 11 and the substrate 14 are measured. Corrected coordinates are generated based on the distance and the carriage moving speed of both, and the substrate 14 is corrected in accordance with the corrected coordinates.
The droplets are applied while moving the discharge head unit 11 and the discharge head unit 11. As the detection optical system 32, a combination of a CCD camera or the like and a lens is used, and as the image identification mechanism 36, a commercially available one that binarizes an image and obtains the position of the center of gravity can be used.

As described above, according to the present invention, the ejection head unit 11 keeps the X,
While moving the carriage in the Y direction, a solution containing a material for the conductive thin film is sprayed to form a surface conduction electron-emitting device group. At this time, if the carriage movement is stopped and the ejection is performed each time the solution for forming each element is ejected, a highly accurate element group can be formed. However, since the productivity is significantly reduced, the solution is sequentially ejected without stopping the carriage movement as described above. In this case, the carriage moving speed (for example, the moving speed of the carriage in the X direction in FIG. 3) should not be determined merely by improving the productivity, but must be considered from the viewpoint of forming a highly accurate element group. No. This will be described later.

Next, other features of the present invention will be described.
In the present invention, as described above, the solution containing the conductive thin film material is caused to fly in the air as droplets by liquid ejection, and is attached to the substrate to form an electron emission portion. When forming the electron-emitting portion by such a method, what must be considered is the stability of the droplet when flying in the air.

If a stable flight of the droplet in the air is performed, the accuracy of the position where the droplet is attached is improved, and a highly accurate electron emission source can be formed. On the other hand, if the adhesion position accuracy of the droplet is poor, a good electron emission source cannot be formed. At the time of flying in the air, droplets are likely to be affected by disturbances such as airflow due to the principle that they fly in the air.Therefore, shut out the disturbances or apply a forcing force to increase stability. Alternatively, by adopting a configuration similar to the above, it is necessary to ensure the stability of the droplet when flying in the air.

In the present invention, in view of the above points,
Stability can be ensured by setting the directionality when the droplet flies in the air or the distance from the time when the droplet is ejected from the ejection head to the time when it adheres to the substrate, and a highly accurate electron emission source can be formed. Was found experimentally.

As described above, in the present invention, the solution containing the conductive thin film material is caused to fly in the air as droplets by liquid ejection while the carriage scans the ejection head 11 in the manufacturing apparatus having the structure shown in FIG. An electron source substrate is manufactured by attaching the electron source substrate to the substrate 14.

In the example shown in FIG. 3, the substrate 14 is arranged horizontally,
Arrange the ejection head mounted on the carriage on it,
An example of a configuration in which a droplet is ejected from top to bottom in a direction in which gravity acts to form an electron source substrate is shown. In the case of such a configuration, since the gravity acts so as to cause the droplet to fly stably, the droplet can fly relatively stably.

However, when the distance from the ejection port surface of the ejection head to the substrate 14 is increased, the time during which the droplets fly in the air is lengthened, and the droplets are easily affected by disturbance.
Therefore, it is considered that the above distance must be set within a certain range.

In the example shown in FIG. 3, the droplet is ejected downward. However, the manufacturing apparatus of the present invention does not always eject the droplet downward. Due to the configuration of the manufacturing apparatus, there may be a configuration in which droplets are ejected obliquely downward or upward. In the present invention, in consideration of the above points, in such a case, the distance from the ejection port surface of the ejection head 11 to the substrate 14 can be set so that the droplet can fly stably in the air, and the electron emission can be performed with high accuracy. It was found experimentally whether a source could be formed. The results are shown below.

FIG. 6 is a schematic diagram showing an example of the arrangement of the substrate and the ejection head. In the drawing, reference numeral 11 denotes an ejection head, 11a denotes an ejection port surface, 14 denotes a substrate, 43 denotes a droplet, and G denotes a direction of gravity. is there. In the experiment, the arrangement of the substrate 14 was made substantially horizontal as shown in FIG. 6A, and the droplets were ejected from the top to the bottom, and as shown in FIG. FIG. 6 shows a configuration in which the droplet 43 is ejected obliquely downward from above by holding the liquid crystal clockwise at an angle larger than 0 degree and smaller than 90 degrees.
As shown in (C), the substrate 14 is held at an angle greater than 90 degrees and less than 180 degrees clockwise with respect to the horizontal, and the droplets 43 are ejected obliquely upward from below. The flight stability of the droplet 43 was examined by changing the distance L from the ejection port surface to the substrate 14. Note that the flying state cannot be directly observed and observed.
The shape of the droplet applied above was evaluated.

As shown in FIGS. 6B and 6C,
When the substrate 14 is arranged at an angle with respect to the horizontal, the droplets 43 are ejected in a direction perpendicular to the substrate 14, so that the ejection angle is also 0 from the vertical direction (gravity action direction G). Will have a large angle. At this time, FIG.
In the case of the configuration of FIG. 6B, the angle of injection is in the range of 90 to 180 degrees clockwise with respect to the horizontal, and in the case of FIG. 6C, the angle of injection is clockwise with respect to the horizontal. From 0 to 9
Within the range of 0 degrees. In the actual experiment shown below, FIG.
(B), the angle of the substrate 14 is about 45 degrees clockwise with respect to the horizontal (the injection angle is about 1 degree clockwise with respect to the horizontal).
35C), and the angle of the substrate 14 is about 135 degrees clockwise with respect to the horizontal as shown in FIG. 6C (the injection angle is about 45 degrees clockwise with respect to the horizontal).

Strictly speaking, in the configuration of FIG. 6B, the angle of the injection has a range of 90 degrees to 180 degrees clockwise with respect to the horizontal, and in the configuration of FIG. It seems that it is difficult to express all with only one certain angle setting because the angle of R has a range of 0 to 90 degrees clockwise with respect to the horizontal. Through an (experiment for evaluating the shape of the droplet on the substrate), the distance L from the ejection surface 11a of the ejection head to the substrate 14 is smaller than this angle.
Was found to have a large contribution rate. Therefore, in order to prevent complication, here, in the case of the configuration of FIG. 6B, the angle of the substrate 14 is approximately 45 degrees clockwise with respect to the horizontal (the injection angle is approximately 135 degrees clockwise with respect to the horizontal). In the case of the configuration of FIG. 6C, the substrate angle is approximately 135 degrees clockwise with respect to the horizontal (the angle of ejection is approximately 45 degrees clockwise with respect to the horizontal). Only experimental data is shown.

The conditions of the solution and the ejection head used in the actual experiment are shown below. The solution used was an aqueous solution of palladium acetate-triethanolamine and was prepared as follows. First, 100 g of palladium acetate was suspended in 2000 cc of isopropyl alcohol, and 407 g of triethanolamine was added to the suspension.
Stirred at 12 ° C. for 12 hours. After completion of the reaction, isopropyl alcohol was removed by evaporation, and ethyl alcohol was added to the solid to dissolve and filter, and palladium acetate-triethanolamine was recrystallized from the filtrate to obtain. 8 g of the thus obtained palladium acetate-triethanolamine was added to 39
Dissolved in 2 g of pure water and used for experiments (2.0 wt.
%).

The ejection head 11 used was of an edge shooter type thermal ink jet system, the nozzle diameter was 26 μm, the heating element size was 26 μm × 118 μm (resistance value 101Ω), the driving voltage was 24.5 V, and the pulse width was 6 μs. 6 m / s is obtained as the initial jet speed when the jet is driven and jetted downward. Carriage scanning speed (X
Direction) was 5 m / s.

The results are shown in Table 1 below. Here, the results of evaluating the state of element formation on the substrate 14 by ejecting droplets while changing the distance L from the ejection port surface 11a of the ejection head to the substrate 14 are shown. The element formation status on the substrate is indicated by ○ when the element was successfully formed and × when the element image was deformed to such an extent that the element image could not be used due to the slight flow of the solution image.

[0057]

[Table 1]

From the above results, when the distance L from the ejection port surface of the ejection head to the substrate is 0.05 mm, FIG.
In all of the configurations shown in FIGS. 6A, 6B, and 6C, good device formation could not be performed. This is because the distance L is too short, so that the droplet 43
This is because they reach the substrate 14 before being separated from 1a.

When the droplet 43 is ejected from the ejection head 11 almost downward from above and is applied to the substrate 14 (FIG. 6A), the distance L from the ejection port surface of the ejection head to the substrate is determined. It can be seen that good element formation can be performed when the thickness is in the range of 0.1 mm to 10 mm, but when the distance L is further increased, good element formation cannot be performed gradually. This is because the distance L increases.
This is because the flight distance in the air becomes longer, and during that time, it becomes more susceptible to disturbance.

Similarly, when the droplet 43 is ejected obliquely downward from the ejection head 11 and applied to the substrate 14 (FIG. 6B), the substrate 1 is ejected from the ejection opening face of the ejection head 11.
It can be seen that when the distance L to 4 is in the range of 0.1 mm to 8 mm, good element formation can be performed, but when the distance L is further increased, good element formation cannot be performed gradually. This is because, as the distance L increases, the flight distance in the air increases, and during that time, the air becomes more susceptible to disturbance. Also, compared to the case where the droplet 43 is ejected substantially downward from above and applied to the substrate 14,
The reason that the distance L at which a good element can be formed becomes smaller is that the gravitational action direction G coincides with the direction of the ejection as compared with the case where the droplet 43 is ejected almost downward from above and applied to the substrate. Because there is no.

Further, when the droplet 43 is ejected from the ejection head 11 obliquely upward from below and applied to the substrate 14 (FIG. 6C), the substrate 1 is ejected from the ejection port surface of the ejection head 11.
It can be seen that when the distance L to 4 is in the range of 0.1 mm to 6 mm, good element formation can be performed, but when the distance L is further increased, good element formation cannot be performed gradually. This is because, as the distance L increases, the flying distance of the droplet 43 in the air increases, and during that time, the droplet 43 is easily affected by disturbance.

The distance L over which a good element can be formed is smaller than when the droplet 43 is ejected substantially downward from above and applied to the substrate 14, or when the droplet 43 is ejected obliquely downward from above. This is because the gravitational action direction G does not coincide with the direction of jetting, or gravitational force acts in the direction opposite to the direction of jetting.

Next, still another feature of the present invention will be described. As described above, in the present invention, in order to prevent a decrease in productivity, the solution is sequentially ejected while scanning the carriage without stopping the scanning of the carriage on which the ejection head 11 is mounted. In this case, the carriage scanning speed (for example, the moving speed of the carriage 12 in the X direction in FIG. 3) should not be determined merely by improving the productivity, but must be examined from the viewpoint of forming a highly accurate element group. Must.

In the present invention, as a result of intensive studies on this point, it has been found that when a solution containing such a conductive thin film material is jetted, the jetting speed must be higher than the carriage moving speed. noticed. In this manner, while performing the carriage scanning in the X and Y directions while keeping the distance of the ejection head unit 11 to the substrate 14 constant, the solution containing the material of the conductive thin film is ejected, and the surface conduction type electron-emitting device group is formed. In the case of forming, the droplet 43 of the solution is attached and formed on the substrate 14 at a speed of a combined vector of the carriage scanning speed and the ejection speed. Regarding the positional accuracy, the substrate 14 and the ejection head unit 11
The droplet 43 can be made to adhere to a target position by appropriately selecting the timing of the ejection in consideration of the distance of the solution ejection port surface and the speed of the combined vector.

However, even if the droplet 4
However, if the carriage scanning speed is too high, the attached droplets are dragged by the carriage scanning speed and flow on the substrate 14 so that the electron emitting element group can be formed in a good shape. It cannot be formed. The present invention has examined this point. The following are the results of the study
Here is an example. In this example, using the apparatus as shown in FIG. 3, it is examined whether or not good droplet deposition can be performed on the substrate 14 by changing the moving speed of the carriage 12 in the X direction and the ejection speed of the ejection head unit 11. It is a thing.

The solution used was palladium acetate-
It is an aqueous solution of triethanolamine and is produced as follows. That is, 100 g of palladium acetate was suspended in 2000 cc of isopropyl alcohol, and 407 g of triethanolamine was added to the suspension.
Stirred at 12 ° C. for 12 hours. After completion of the reaction, isopropyl alcohol was removed by evaporation, ethyl alcohol was added to the solid to dissolve and filter, and palladium acetate-triethanolamine was recrystallized from the filtrate to obtain. 8 g of the thus obtained palladium acetate-triethanolamine was added to 39
Dissolved in 2 g of pure water and used for experiments (2.0 wt.
%).

The ink jet head used was an edge shooter type thermal ink jet system.
Nozzle diameter is Φ26μm, heating element size is 28μm × 11
8 μm (resistance value 101Ω), and the driving voltage is 24V to 27V.
V, the pulse width was 6 μs, and the energy for forming one drop was changed from 37 μJ to 43 μJ.

Table 2 shows the results. Here, the element formation state on the substrate is indicated by "O" when the element was successfully formed, and "x" when the element was deformed to such an extent that the element shape could not be used due to the slight flow of the solution image.

[0069]

[Table 2]

From the above results, it can be seen that if the moving speed of the carriage in the X direction is higher than the ejection speed, a good element cannot be formed. In other words, when manufacturing an electron source substrate using the apparatus according to the present invention, it is understood that the speed of the droplet ejected from the ejection head must be faster than the moving speed of the carriage in the X direction.

The solution containing the material of the conductive thin film is sprayed by the above means to pattern the surface-conduction electron-emitting device group. In the present invention, the forming process described below is performed. Thereby, the electron emission portion 5 is formed. The electron emission portion 5 is constituted by a high-resistance crack formed in a part of the conductive thin film 4.
It depends on the film thickness, film quality, material, etc., or the forming processing conditions, etc. The inside of the electron emission section 5 has 1
It may contain conductive fine particles having a particle size of not more than 000 °.
The conductive fine particles contain some or all of the elements of the material constituting the conductive thin film 4.
The electron-emitting portion 5 and the conductive thin film 4 in the vicinity thereof may contain carbon or a carbon compound.

As an example of a forming method applied to the conductive thin film 4, a method using an energization process will be described. When power is applied between the device electrodes 2 and 3 using a power supply (not shown),
An electron-emitting portion 5 having a changed structure is formed at a portion of the conductive thin film 4. That is, according to the energization forming, a portion of the conductive thin film 4 where a structural change such as destruction, deformation or alteration is locally formed, and this portion becomes the electron emission portion 5. FIG. 7 shows an example of the voltage waveform of the energization forming. A pulse waveform is particularly preferable as the voltage waveform, and a voltage pulse having a constant pulse peak value is continuously applied (FIG. 7A).
And a case where a voltage pulse is applied while increasing the pulse peak value (FIG. 7B). First, the case where the pulse peak value is a constant voltage (FIG. 7A) will be described.

In FIG. 7A, T1 and T2 are the pulse width and pulse interval of the voltage waveform, and T1 is 1 μs to 1 μs.
0 ms and T2 are 10 μs to 100 ms. The peak value of the triangular wave (peak voltage at the time of energization forming) is appropriately selected according to the form of the surface conduction electron-emitting device. Under such conditions, for example, a voltage is applied for several seconds to tens of minutes. The pulse waveform is not limited to a triangular wave, and a desired waveform such as a rectangular wave may be used.

T1 and T2 in FIG. 7B are the same as those shown in FIG. 7A, and the peak value of the triangular wave (peak voltage during energization forming) is, for example, 0.1.
It can be increased by about V steps.

The end of the energization forming process can be detected by applying a voltage that does not locally destroy or deform the conductive thin film 4 during the pulse interval T2, and measuring the current. For example, a device current flowing by applying a voltage of about 0.1 V is measured, a resistance value is obtained, and when a resistance of 1 MΩ or more is indicated, the energization forming is terminated.

It is desirable to perform a process called an activation step on the element after the energization forming. By performing the activation process, the device current If and the emission current Ie change significantly. The activation step can be performed, for example, by repeatedly applying a pulse in an atmosphere containing an organic substance gas, similarly to the energization forming. This atmosphere is
For example, it can be formed by using the organic gas remaining in the atmosphere when the inside of the vacuum vessel is discarded using an oil diffusion pump or a rotary pump, or in a vacuum once sufficiently exhausted by an ion pump or the like. It can also be obtained by introducing a gas of an organic substance. The preferable gas pressure of the organic substance at this time varies depending on the above-described application form, the shape of the vacuum vessel, the type of the organic substance, and the like, and is appropriately set according to the case.

The above-mentioned suitable organic substances include alkanes, alkenes, aliphatic hydrocarbons of alkynes, aromatic hydrocarbons, alcohols, aldehydes, ketones, amines, phenols, carboxylic acids, sulfonic acids and the like. Organic acids and the like, specifically, saturated hydrocarbons represented by C _n H _{2n + 2} such as methane, ethane, and propane;
Ethylene, propylene C _n H _2n such unsaturated hydrocarbon represented by composition formula such as benzene, toluene, methanol,
Formaldehyde, acetaldehyde, acetone, methyl ethyl ketone, methylamine, ethylamine, phenol, formic acid, acetic acid, propionic acid and the like can be used. By this treatment, carbon or a carbon compound is deposited on the device from the organic substance existing in the atmosphere, and the device current If and the emission current Ie are significantly changed. The end of the activation step is determined while measuring the device current If and the emission current Ie. Note that the pulse width, pulse interval, pulse peak value, and the like are set as appropriate.

The carbon or the carbon compound includes graphite (both single crystal and polycrystal) and amorphous carbon (carbon including amorphous carbon and a mixture of amorphous carbon and the above-mentioned graphite fine crystals). The thickness is preferably not more than 500 °, more preferably not more than 300 °.

It is preferable that the electron-emitting device thus manufactured is subjected to a stabilization process. This treatment is preferably performed at a partial pressure of the organic substance in the vacuum vessel of 1 × 10 ⁻⁸ Torr or less, preferably 1 × 10 ⁻¹⁰ Torr or less. The pressure in the vacuum vessel is preferably 10 ^-6 to 10 ^-7 Torr or less, and particularly preferably 1 × 10 ^-8 Torr or less. It is preferable to use a vacuum exhaust device that does not use oil so that the oil generated from the device does not affect the characteristics of the element. Specifically, a vacuum exhaust device such as a sorption pump or an ion pump can be used. Further, when the inside of the vacuum vessel is evacuated, it is preferable to overheat the entire vacuum vessel so that the organic substance molecules adsorbed on the inner wall of the vacuum vessel or the electron-emitting device can be easily evacuated. The vacuum evacuation conditions in the heated state at this time are desirably 5 hours or more at 80 to 200 ° C., but are not particularly limited to these conditions, and include the size and shape of the vacuum vessel, the configuration of the electron-emitting device, and the like. Varies depending on the conditions. In addition, the partial pressure measurement of the organic substance is performed using a mass spectrometer with a mass number of 10 to 2
It is determined by measuring the partial pressures of organic molecules having carbon and hydrogen of 00 as main components and integrating the partial pressures.

After the stabilization step as described above, the atmosphere during driving is preferably the same as that at the end of the stabilization process, but is not limited to this, and the organic substance is sufficiently removed. In this case, even if the degree of vacuum itself is slightly reduced, it is possible to maintain sufficiently stable characteristics. By adopting such a vacuum atmosphere, the deposition of new carbon or a carbon compound can be suppressed, and as a result, the device current If,
The emission current Ie is stabilized.

Next, the image forming apparatus of the present invention will be described. Various arrangements of the electron emission elements of the electron source substrate used in the image forming apparatus can be adopted. First, each of a large number of electron-emitting devices arranged in parallel is connected at both ends, a large number of rows of electron-emitting devices are arranged (referred to as a row direction), and electrons are arranged in a direction orthogonal to the wiring (referred to as a column direction). By the control electrode (also called grid) arranged in the information of the emission element,
There is a ladder-type arrangement for controlling and driving electrons from an electron-emitting device. Separately, a plurality of electron-emitting devices are arranged in a matrix in the X and Y directions, and one of the electrodes of the plurality of electron-emitting devices arranged in the same row is commonly connected to a wiring in the X direction. One example is one in which the other of the electrodes of a plurality of electron-emitting devices arranged in the same column is commonly connected to a wiring in the Y direction. Such is the so-called simple matrix arrangement. First, the simple matrix arrangement will be described in detail below.

FIG. 8 is a view for explaining an electron source substrate obtained by arranging a plurality of electron-emitting devices of the present invention in a matrix on a substrate. In FIG.
52 is a Y-direction wiring; 53 is a surface conduction electron-emitting device;
Reference numeral 4 denotes a connection, and reference numeral 10 denotes an electron source substrate formed by forming a surface conduction electron-emitting device on the substrate 14. m X-direction wires 7
2 is composed of DX1, DX2,... DXm,
DY1, DY2,... DYn
Of the n wirings. Further, the material, the film thickness, and the wiring width are appropriately set so that a substantially uniform voltage is supplied to many surface conduction electron-emitting devices 53. The m X-directional wirings 51 and the n Y-directional wirings 52 are electrically separated by an interlayer insulating layer (not shown) to form a matrix wiring (m and n are both positive integers).

The interlayer insulating layer (not shown) is formed in a part of a desired region on the entire surface of the substrate 14 on which the X-directional wiring 51 is formed. The X-direction wiring 51 and the Y-direction wiring 52 are respectively drawn as external terminals. Further, the device electrodes (not shown) of the surface conduction electron-emitting device 53 are electrically connected to the m X-directional wires 51 and the n Y-directional wires 52 by a connection 54. The material forming the X-direction wiring 51 and the Y-direction wiring 52, the material forming the connection 54, and the material forming the pair of element electrodes are different even if some or all of the constituent elements are the same. May be.
These materials are appropriately selected, for example, from the above-described materials for the device electrodes. When the material forming the element electrode is the same as the wiring material, the wiring connected to the element electrode can also be called an element electrode.

The X-direction wiring 51 is electrically connected to a scanning signal generating means (not shown) for applying a scanning signal for scanning a row of the surface conduction electron-emitting devices 53 arranged in the X direction in accordance with an input signal. It is connected. On the other hand, the Y-direction wiring 52
Are electrically connected to a modulation signal generating means (not shown) for applying a modulation signal for modulating each column of the surface conduction electron-emitting devices 53 arranged in the Y direction according to an input signal. Further, the drive voltage applied to each element of the surface conduction electron-emitting device 53 is supplied as a difference voltage between a scanning signal and a modulation signal applied to the element. As a result, individual elements can be selected and driven independently using only simple matrix wiring.

Next, an image forming apparatus using the electron source substrates of the simple matrix arrangement prepared as described above will be described with reference to FIGS. FIG. 8 is a diagram for explaining a basic configuration of a display panel of the image forming apparatus, and FIG. 10 is a partially enlarged view showing a configuration of a fluorescent film used in the display panel. FIG. 11 is a diagram showing a driving circuit for performing display according to an NTSC television signal, and an image forming apparatus including the driving circuit.

In FIG. 9, reference numeral 10 denotes an electron source substrate formed by forming a surface conduction electron-emitting device 53 on the substrate; 61, a rear plate on which the electron source substrate 10 is fixed; 66, a fluorescent film on the inner surface of a glass substrate 63; A face plate 62 on which a metal back 64 and a metal back 65 are formed, a support frame 62, a rear plate 61, a support frame 62, and a face plate 66
Then, frit glass or the like is applied, and the container is fired at 400 to 500 degrees in air or nitrogen for 10 minutes or more to seal the envelope 68. Surface conduction electron-emitting device 53
Corresponds to the electron-emitting device in FIG. In FIG. 8, reference numerals 51 and 52 denote an X-direction wiring and a Y-direction wiring connected to a pair of device electrodes of the surface conduction electron-emitting device, respectively.

The envelope 68 comprises the face plate 66, the support frame 62, and the rear plate 61 as described above.
Since the rear plate 61 is provided mainly for the purpose of reinforcing the strength of the electron source substrate 14, if the electron source substrate 10 itself has a sufficient strength, the separate rear plate 61 is unnecessary, and the electron source substrate 10 The support frame 62 may be directly sealed, and the envelope 68 may be configured by the face plate 66, the support frame 62, and the electron source substrate 10. Further, by installing an anti-atmospheric pressure support member called a spacer between the face plate 66 and the rear plate 61, the envelope 68 having sufficient strength against atmospheric pressure can be obtained.

In the case of a monochrome phosphor, only the phosphor is used. In the case of a color phosphor film, a black stripe as shown in FIG. 10A or FIG. And a black conductive material 71 called a black matrix. The purpose of providing the black stripes and the black matrix is to make the color separation between the phosphors 72 of the necessary three primary color phosphors black in color display to make color mixing less noticeable, The purpose is to suppress a decrease in contrast due to light reflection. The material of the black stripe is not limited to a commonly used material containing graphite as a main component, as long as it is conductive and has little light transmission and reflection.

In the present invention, the direction of the stripe of the matrix-formed phosphor as described above, or the two directions orthogonal to each other in the matrix, are set in parallel with the two directions orthogonal to each other in the above-described electron-emitting device group. And the phosphors are positioned and laminated so that the phosphors coincide with the respective electron-emitting devices to constitute an image display device. Since the directions and positions of the matrices of the image display devices having such a configuration match each other, an image display device with extremely high image quality can be realized.

As a method of applying a phosphor on the glass substrate 63, a precipitation method or a printing method is used regardless of monochrome or color. A metal back 65 is usually provided on the inner surface side of the fluorescent film 64 (FIG. 9). Metal back 65
Is to improve the brightness by mirror-reflecting the light toward the inner surface side of the phosphor emission toward the face plate 66 side, to act as an electrode for applying an electron beam acceleration voltage, and within the envelope. It has a role such as protecting the phosphor from damage caused by the collision of the generated negative ions.
The metal back 65 can be manufactured by performing a smoothing process (usually called filming) on the inner surface of the fluorescent film 64 after manufacturing the fluorescent film 64, and then depositing Al by vacuum evaporation or the like.

The face plate 66 is further provided with the fluorescent film 6.
A transparent electrode (not shown) may be provided on the outer surface side of the fluorescent film 64 in order to enhance the conductivity of the phosphor film 4. When the above-mentioned sealing is performed, in the case of color, the phosphors of each color must correspond to the electron-emitting devices, and it is necessary to perform sufficient alignment. In order to perform this sufficient alignment, according to the present invention, as described above, the phosphor is disposed at a position facing the electron-emitting device, and two mutually orthogonal directions of the respective matrices are parallel to each other. I have to.

In order to obtain a high-precision image display device having the above configuration, it is desirable that the phosphor substrate also employs the same positioning technique as the electron source substrate of the present invention. The image forming apparatus shown in FIG. 9 is specifically manufactured as follows. The envelope 68 is evacuated through an exhaust pipe (not shown) by an exhaust device that does not use oil, such as an ion pump and a sorption pump, while appropriately heating the envelope 68 in the same manner as in the above-described stabilization process, and a vacuum degree of about 10 ⁻⁷ Torr After the atmosphere of the organic material is made sufficiently small, the substrate is sealed. A getter process may be performed in order to maintain the degree of vacuum after sealing the envelope 68. This is performed by a heating method such as resistance heating or high-frequency heating immediately before or after sealing the envelope 68.
This is a process of heating a getter disposed at a predetermined position (not shown) in the envelope 68 to form a vapor deposition film. The getter is usually composed mainly of Ba or the like and, for example, 1 × 10 ⁻⁵ Torr to 1 × 10 ⁻⁷ Torr due to the adsorption action of the deposited film.
The vacuum degree of r is maintained.

FIG. 11 shows a case where a display panel constituted by using an electron source having a simple matrix arrangement type substrate is driven and N
FIG. 2 is a diagram showing a schematic configuration of a driving circuit for performing television display based on a TSC system television signal, in which 81 is a display panel for displaying an image, 82 is a scanning circuit, 83 is a control circuit, and 84 is a shift register , 85 is a line memory,
86 is a synchronization signal separation circuit, 87 is a modulation signal generator, Vx
And Va are DC voltage sources.

The function of each section will be described below. First, the display panel 81 is connected to the terminals Dox1 to Doxm and the terminal Dx.
It is connected to an external electric circuit via oy1 to Doyn and the high voltage terminal Hv. Of these terminals, the terminals Dox1 to Doxm sequentially drive electron sources provided in the display panel 81, that is, a group of surface conduction electron-emitting devices arranged in a matrix of M rows and N columns, one row at a time (N elements). A scanning signal for moving is applied. On the other hand, to the terminals Doy1 to Doyn, a modulation signal for controlling an output electron beam of each element of the one row of surface conduction electron-emitting devices selected by the scanning signal is applied. A DC voltage of, for example, 10 kV is supplied to the high voltage terminal Hv from the DC voltage source Va, which applies sufficient energy to the electron beam output from the surface conduction electron-emitting device to excite the phosphor. Is the accelerating voltage for

Next, the scanning circuit 82 will be described. This circuit has M switching elements inside (in the figure, S1 to Sm are schematically shown), and each switching element is an output voltage of a DC voltage source Vx or 0V.
(Ground level), and is electrically connected to the terminals Dox1 to Doxm of the display panel 81. Each of the switching elements S1 to Sm operates based on the control signal Tscan output from the control circuit 83, but can be actually configured by combining switching elements such as FETs. Note that the DC voltage source Vx is such that the drive voltage applied to an element that is not scanned based on the characteristics (electron emission threshold voltage) of the surface conduction electron-emitting element is equal to or lower than the electron emission threshold voltage. It is set to output a constant voltage.

The control circuit 83 has a function of matching the operations of the respective units so that an appropriate display is performed based on an image signal input from the outside. Based on the synchronization signal Tsync sent from the synchronization signal separation circuit 86 described below, Tscan, Tsft, and Tm
ry control signals are generated.

The synchronizing signal separating circuit 86 is a circuit for separating a synchronizing signal component and a luminance signal component from an NTSC television signal input from the outside, and can be formed by using a frequency separating (filter) circuit. It is.
As is well known, the synchronization signal separated by the synchronization signal separation circuit 86 is composed of a vertical synchronization signal and a horizontal synchronization signal, but is shown here as a Tsync signal for convenience of explanation. On the other hand, a luminance signal component of an image separated from the television signal is referred to as a DATA signal for convenience, and the signal is input to a shift register 84.

The shift register 84 is for serially / parallel converting the DATA signal input serially in time series for each line of an image, and operates based on a control signal Tsft sent from the control circuit 83. I do. That is, the control signal Tsft is
May be rephrased as the shift clock. One line of serial / parallel converted image (electron emitting element N
(Corresponding to drive data for the elements) is output from the shift register 84 as N parallel signals Id1 to Idn.

The line memory 85 is a storage device for storing data for one line of an image for a required time only.
The contents of Id1 to Idn are stored as appropriate according to the control signal Tmry sent from the control circuit 83. The stored contents are output as Id1 to Idn and input to the modulation signal generator 87.

The modulation signal generator 87 outputs the image data Id
A signal source for appropriately driving and modulating each of the surface conduction electron-emitting devices according to each of 1 to Idn, and an output signal thereof is sent to the surface conduction electron-emitting device in the display panel 81 through terminals Doy1 to Doyn. Applied.

As described above, the electron-emitting device according to the present invention has the following basic characteristics with respect to the emission current Ie. That is, as described above, electron emission has a clear threshold voltage Vth, and electron emission occurs only when a voltage higher than Vth is applied. For a voltage equal to or higher than the electron emission threshold, the emission current also changes according to the change in the voltage applied to the element. The electron emission threshold voltage Vth can be changed by changing the material, configuration, and manufacturing method of the electron emission element.
In some cases, the degree of change of the emission current with respect to the value or the applied voltage changes, but in any case, the following can be said.

That is, when a pulse-like voltage is applied to the device, for example, when a voltage lower than the electron emission threshold is applied, electron emission does not occur but a voltage higher than the electron emission threshold is applied. Outputs an electron beam. that time,
First, it is possible to control the intensity of the output electron beam by changing the pulse peak value Vm. Second, it is possible to control the total amount of charges of the output electron beam by changing the pulse width Pw.

Therefore, as a method of modulating the electron-emitting device in accordance with the input signal, there are a voltage modulation method, a pulse width modulation method and the like. A voltage modulation circuit that generates a voltage pulse having a length corresponding to the pulse length, and modulates the peak value of the pulse appropriately according to input data is used. To implement the pulse width modulation method, the modulation signal generator 87
A voltage pulse having a constant peak value is generated, but a pulse width modulation type circuit that appropriately modulates the width of the voltage pulse according to input data is used. The shift register 84 and the line memory 85 may be of a digital signal type or an analog signal type, and it is essential that the serial / parallel conversion and storage of the image signal be performed at a predetermined speed.

When a digital signal type is used,
It is necessary to convert the output signal DATA of the synchronization signal separation circuit 86 into a digital signal. This can be achieved by providing an A / D converter at the output of the synchronization signal separation circuit 86. In connection with this, the circuit used for the modulation signal generator 87 is slightly different depending on whether the output signal of the line memory 85 is a digital signal or an analog signal.

First, the case of a digital signal will be described.
In the voltage modulation method, for example, a well-known D / A conversion circuit may be used as the modulation signal generator 87, and an amplification circuit or the like may be added as necessary. In the case of the pulse width modulation method, the modulation signal generator 87 includes, for example, a high-speed oscillator,
A counter for counting the number of waves output by the oscillator,
And a circuit combining a comparator (comparator) for comparing the output value of the counter with the output value of the line memory 85. If necessary, an amplifier for amplifying the voltage of the pulse width modulated signal output from the comparator to the drive voltage of the surface conduction electron-emitting device may be added.

Next, the case of an analog signal will be described.
In the voltage modulation method, for example, an amplification circuit using a well-known operational amplifier or the like may be used as the modulation signal generator 87, and a level shift circuit or the like may be added as necessary. In the case of the pulse width modulation method, for example, a well-known voltage-controlled oscillation circuit (VCO) may be used, and an amplifier for amplifying the voltage up to the driving voltage of the surface conduction electron-emitting device may be added as necessary. You may.

In the image display device having the above-described configuration, each electron-emitting device of the display panel 81 has an external terminal Dox1 to Doxm, Doy1 to Doyn.
Through the high voltage terminal Hv to apply a high voltage to the metal back 65 or a transparent electrode (not shown) to accelerate the electron beam, collide with the fluorescent film 64, and excite An image can be displayed by emitting light.

The configuration described here is a schematic configuration necessary for manufacturing a suitable image forming apparatus used for display or the like. For example, detailed portions such as materials of each member are not limited to those described above. Instead, it is appropriately selected so as to be suitable for the use of the image forming apparatus. Although the NTSC system has been described as an example of the input signal, the present invention is not limited to this, and PAL, SECA
Various systems such as the M system may be used, and a TV signal composed of a larger number of scanning lines (for example, a high-definition TV including the MUSE system) may be used.

Next, the ladder-type arranged electron source substrate and the image display device will be described with reference to FIGS. 12, reference numeral 10 denotes an electron source substrate, 14 denotes a substrate constituting the electron source substrate, 53 denotes an electron-emitting device, and 91 denotes common wirings Dx1 to Dx10 connected to the electron-emitting device 53. A plurality of electron-emitting devices 91 are arranged on the substrate 14 in parallel in the X direction. This is called an element row. A plurality of the element rows are arranged on a substrate to form an electron source substrate. By applying a drive voltage between the common wires of each element row, each element row can be driven independently. That is, a voltage equal to or higher than the electron emission threshold may be applied to an element row in which an electron beam is to be emitted, and a voltage equal to or lower than the electron emission threshold may be applied to an element row in which an electron beam is not emitted. Further, common wirings Dx2 to Dx9 between the element rows, for example, Dx2, Dx2
x3 may be the same wiring.

FIG. 13 is a view for explaining a panel structure in an image forming apparatus provided with the above-mentioned ladder-type arrangement of electron sources. In the figure, reference numeral 110 denotes a grid electrode, and 111 denotes a space through which electrons pass. Hole 112 is Dox1, Dox2
... Outer container terminals made of Doxm, 113 denotes outer terminals made of G1, G2,... Gn connected to the grid electrode 110, 114 denotes an electron source substrate in which common wiring between element rows is the same wiring. is there. 13, the same reference numerals as those in FIG. 9 and / or FIG. 11 indicate the same members. The difference from the image forming apparatus having the simple matrix arrangement (FIG. 1) is whether or not the grid electrode 110 is provided between the electron source substrate 114 and the face plate 66.

The grid electrode 110 is for modulating the electron beam emitted from the surface conduction electron-emitting device, and passes the electron beam to a stripe-shaped electrode provided orthogonal to the ladder-shaped device row. For this purpose, one circular opening 111 is provided for each element. The shape and installation position of the grid are not limited to those shown in FIG. For example, a large number of passage openings may be provided in a mesh shape instead of the openings 111, and a grid may be provided around or near the surface conduction electron-emitting device. Outer container terminal 112 and grid outer terminal 113
Are electrically connected to a control circuit (not shown).

In the present image forming apparatus, a modulation signal for one line of an image is simultaneously applied to the grid electrode rows in synchronization with sequentially driving (scanning) the element rows one by one. Thus, the irradiation of each electron beam to the phosphor is controlled, and one image is displayed.
Can be displayed line by line. According to this, in addition to a display device of a television broadcast, a video conference system, a display device of a computer or the like, it can also be used as an image forming device as an optical printer including a photosensitive drum or the like.

[0113]

According to a first aspect of the present invention, there is provided an apparatus for manufacturing an electron source substrate, wherein an electron emitting element group having a conductive thin film that emits electrons by applying a predetermined voltage is formed on the substrate. A plurality of pairs of respective elements provided on the substrate based on input droplet application information, the substrate holding means having a substrate holding / positioning means or a holding position adjusting mechanism, and being provided at a position opposed to the substrate; An ejection head that forms the conductive thin film by ejecting a solution containing the material of the conductive thin film between electrodes, an information input unit that inputs the droplet applying information to the ejection head, and the ejection head. A carriage mounted and movable in two directions orthogonal to each other in a region facing the substrate, the carriage comprising a solution ejection port surface of the ejection head and a conductive thin film forming surface of the substrate; Since the injection of the solution while scanning to maintain a constant distance, it is possible to fabricate such an electron source substrate with a simple structure.

(Effects Corresponding to Claim 2) The substrate comprises:
The substrate is held by the substrate holding means so that the conductive thin film forming surface of the substrate is horizontal.The jet head is positioned above the substrate and jets the solution downward, and the predetermined distance is equal to 0. Since it is configured to be in the range of 1 mm to 10 mm, the solution jetting is stable with a simple configuration, so that the landing position accuracy of the droplet is high and the surface conduction type emission element group is formed with high accuracy. An electron source substrate can be manufactured.

(Effects Corresponding to Claim 3) The substrate comprises:
The substrate holding means holds the conductive thin film forming surface of the substrate at an angle of more than 0 degree and 90 degrees or less with respect to the horizontal, and the ejection head is configured to conduct the conductive thin film of the substrate from above or from the side of the substrate. The solution is sprayed almost perpendicularly to the forming surface, and the predetermined distance is configured to be in a range of 0.1 mm to 8 mm. It is possible to manufacture an electron source substrate on which a surface conduction type emission element group is formed with high accuracy of droplet landing position and high accuracy.

(Effects Corresponding to Claim 4) The substrate comprises:
The substrate holding means holds the surface on which the conductive thin film is formed at an angle of more than 90 degrees and not more than 180 degrees with respect to the horizontal, and the ejection head is provided on the surface on which the conductive thin film is formed from the side or below the substrate. The solution is ejected almost perpendicularly to the nozzle, and the fixed distance is configured to be in a range of 0.1 mm to 6 mm. It is possible to manufacture an electron source substrate on which a surface conduction electron-emitting device group is formed with high landing position accuracy and high accuracy.

(Effect Corresponding to Claim 5) Since the jetting speed of the solution is faster than the scanning speed of the carriage, the surface conduction electron-emitting device can be formed with extremely high accuracy without breaking the shape of the electron-emitting device to be formed. A group of electron source substrates can be manufactured.

(Effect Corresponding to Claim 6) Since the electron source substrate is manufactured by the apparatus for manufacturing an electron source substrate according to any one of claims 1 to 5, even if it is large, it is manufactured at low cost and high accuracy. An electron source substrate can be obtained.

(Effects Corresponding to Claim 7) The invention according to claim 7 includes the electron source substrate according to claim 6, and a phosphor that can be disposed to face the electron source substrate, wherein the electron source substrate By causing the emitted electrons to collide with the phosphor to cause the phosphor to emit light and display, a high-quality image display device can be obtained.

[Brief description of the drawings]

1A and 1B are a plan view and a side view schematically showing a configuration of a flat surface conduction electron-emitting device formed according to the present invention.

FIG. 2 is a diagram for explaining a method of manufacturing the surface conduction electron-emitting device having the configuration of FIG.

FIG. 3 is a view for explaining an embodiment of a manufacturing apparatus of one electron source substrate of the present invention.

FIG. 4 is a schematic configuration diagram showing a droplet applying apparatus applied to manufacture of an electron source substrate of the present invention.

FIG. 5 is a schematic configuration diagram of a main part of an ejection head unit of the droplet applying apparatus of FIG. 4;

FIG. 6 is a schematic configuration diagram illustrating an example of the arrangement of a substrate and an ejection head.

FIG. 7 is a schematic diagram showing an example of a voltage waveform in an energization forming process that can be employed in manufacturing the surface conduction electron-emitting device according to one embodiment of the present invention.

FIG. 8 is a schematic view showing an example of a matrix arrangement type electron source substrate to which the present invention can be applied.

FIG. 9 is a schematic diagram showing an example of a display panel of an image forming apparatus using a matrix arrangement type electron source substrate to which the present invention can be applied.

FIG. 10 is a schematic view showing a fluorescent film to which the present invention can be applied.

11 is a block diagram illustrating an example of a drive circuit for performing display on the display panel of FIG. 6 in accordance with an NTSC television signal in the image forming apparatus.

FIG. 12 is a view showing an example of a ladder-positioned electron source substrate to which the present invention can be applied.

FIG. 13 is a schematic view showing an example of a display panel of an image forming apparatus using a ladder-positioned electron source substrate to which the present invention can be applied.

FIG. 14 is a schematic view showing an example of a conventional electron-emitting device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Substrate, 2, 3 ... Device electrode, 4 ... Conductive thin film, 5 ... Electron emission part, 7 ... Detection optical system, 8 ... Ink jet head, 9 ... Droplet, 10 ... Electron source substrate, 11 ... Discharge head unit (Ejection head), 12 ... carriage, 13 ... substrate holder, 14 ... substrate, 15 ... supply tube for solution containing conductive thin film material, 16 ... signal supply cable, 1
7, 21: control box, 18: X direction scan motor, 19: Y direction scan motor, 20: computer, 22: substrate positioning / holding means, 31: head alignment control mechanism, 32: detection optical system, 33: inkjet head , 34: Head alignment fine movement mechanism, 35: Control computer, 36: Image identification mechanism, 3
8 position detection mechanism, 39 position correction control mechanism, 40 inkjet head drive / control mechanism, 41 optical axis, 42
... device electrodes, 43 ... droplets, 44 ... droplet landing positions, 51 ...
X-direction wiring, 52: Y-direction wiring, 53: surface conduction electron-emitting device, 54: connection, 61: rear plate, 62: support frame, 63: glass substrate, 64: fluorescent film, 65: metal back, 66 ... Face plate, 67 ... High voltage terminal, 6
8 envelope, 71 black member, 72 phosphor, 81 display panel, 82 scanning circuit, 83 control circuit, 84 shift register, 85 line memory, 86 synchronizing signal separation circuit, 87 Modulation signal generator, 91: common wiring for wiring electron-emitting devices, 110: grid electrode, 11
1 ... void, 112 ... terminal outside the container, 113 ... terminal outside the grid container.

Claims (7)

[Claims] 1. An electron source substrate manufacturing apparatus comprising: a substrate having an electron-emitting device group having a conductive thin film that emits electrons when a predetermined voltage is applied to the substrate; A substrate holding means having a position adjusting mechanism, and a material for the conductive thin film disposed between a plurality of pairs of element electrodes provided on the substrate based on input droplet application information, the material being disposed at a position facing the substrate. Head for forming the conductive thin film by injecting a solution containing, an information input means for inputting the droplet applying information to the ejection head, and an area mounted with the ejection head and facing the substrate And a carriage movable in two directions perpendicular to each other. The carriage maintains scanning at a fixed distance between the solution ejection surface of the ejection head and the surface of the substrate on which the conductive thin film is formed. An apparatus for manufacturing an electron source substrate, wherein the solution is ejected while performing. 2. The substrate is held by the substrate holding means such that a conductive thin film forming surface of the substrate is horizontal, and the ejection head is located above the substrate and ejects the solution downward. And the constant distance is 0.1 mm or more.
The apparatus according to claim 1, wherein the apparatus is configured to have a range of 10 mm. 3. The substrate is held by the substrate holding means at an angle of more than 0 ° and not more than 90 ° with respect to the horizontal surface on which the conductive thin film is formed. The method according to claim 1, wherein the solution is sprayed from a side substantially perpendicularly to a surface of the substrate on which the conductive thin film is formed, and the predetermined distance is in a range of 0.1 mm to 8 mm. 2. An apparatus for manufacturing an electron source substrate according to claim 1. 4. The substrate, wherein the surface on which the conductive thin film is formed is held at an angle of more than 90 degrees and 180 degrees or less with respect to horizontal by the substrate holding means, and the ejection head comprises:
The solution is sprayed substantially perpendicularly to the surface on which the conductive thin film is formed, from the side or below the substrate, so that the predetermined distance ranges from 0.1 mm to 6 mm. The apparatus for manufacturing an electron source substrate according to claim 1. 5. The apparatus according to claim 1, wherein the jetting speed of the solution is higher than the scanning speed of the carriage.
An apparatus for manufacturing an electron source substrate according to any one of the above. 6. An electron source substrate manufactured by the apparatus for manufacturing an electron source substrate according to claim 1. Description: 7. An electron source substrate according to claim 6, and a phosphor that can be disposed so as to face the electron source substrate, wherein electrons emitted by the electron source substrate collide with the phosphor. An image display device, wherein display is performed by emitting light from the phosphor.