JPH1140083A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sufficient evacuation for discharged gas from a fluorescent substance, etc., and to inhibit characteristic deterioration of electron emitting elements, and to inhibit brighness deterioration when operating for a long time, by positioning a metal plate which has electron through holes which electrons emitted from a electron source plate pass through, and a getter material, between the electron source plate and an image forming member. SOLUTION: A display panel 1100 constituting an image forming device is composed of an electron source 171 in which surface conduction electron emitting elements 74 are simple-MTX-arranged, an image forming member 87 which is positioned at a prescribed distance from the electron source 171 and is impressed with electron accelerating voltage, and a metal plate 101 which is positioned between them, and has electron through holes 102 which electrons emitted from the electron source 171 pass through, also is formed of getter material Zr -V-Fe . The electron through holes 102 are provided one by one corresponding to each electron emitting element 74 of the electron source 171. The electron source 171 is fixed on a rear plate 81, and the image forming member 87 is formed to a face plate 86.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flat plate type image forming apparatus using an electron-emitting device.

[0002]

2. Description of the Related Art Conventionally, two types of electron-emitting devices using a thermionic electron-emitting device and a cold-cathode-type electron-emitting device have been known.

As a flat plate type image forming apparatus using a thermionic emission element, for example, Japanese Patent Publication No. 7-99679 and Japanese Utility Model Publication No.
As disclosed in, for example, Japanese Patent No. 8629, etc., an apparatus which controls electrons emitted from a linear cathode by a control electrode group called a grid and displays an image has been put to practical use. On the other hand, a flat plate type image forming apparatus using a cold cathode electron emitting device has an electron source substrate on which a plurality of cold cathode electron emitting devices are arranged, and a face plate on which a phosphor and the like are arranged.
They are arranged facing each other at a distance D (= 1 mm to about 10 mm) via a vacuum. The image forming apparatus emits electrons from each electron-emitting device by applying a scanning signal and a modulation signal to an electron source substrate, accelerates the electrons by an anode voltage Va of several kV applied to a face plate, and generates a phosphor. An image is displayed by emitting light by colliding with.

[0004] Examples of the cold cathode electron-emitting device applied here include a surface conduction electron-emitting device, a MIM-type electron-emitting device, and a Spindt-type field-emission electron-emitting device.

First, an image forming apparatus to which a surface conduction electron-emitting device is applied as a cold cathode electron-emitting device is disclosed in, for example, JP-A-7-235255.
The above-mentioned surface conduction electron-emitting device has an advantage that it can be applied to a large-area image forming apparatus because a large number of devices can be arranged and formed over a large area because of its simple structure and easy manufacture. Japanese Patent Application Laid-Open No. Hei 7-235255 also discloses a basic configuration, a manufacturing process, and a method for configuring a basic electron source of a surface conduction electron-emitting device. As an image forming apparatus in which a potential regulating plate is applied to an image forming apparatus, for example, JP-A-03-149728 and JP-A-08-0019 using surface conduction electron-emitting devices are used.
72. The potential regulating plate is disposed at a distance d from the electron source, has an electron passage hole through which electrons emitted from the electron source pass, and is applied with a constant voltage Vc = <Vaxd / D. As described in the above publication, the potential regulating plate has functions such as preventing discharge due to charging of the insulating surface, suppressing electron orbital deviation, suppressing deterioration of the electron-emitting device due to cations, and the like. Has the function of making the display more stable.

On the other hand, as an example of an image forming apparatus to which a Spindt-type electron-emitting device is applied, Japanese Patent Application Laid-Open No. Hei 4-2436 is cited.

Japanese Patent Application Laid-Open No. 3-55738 discloses an example of an image forming apparatus to which an MIM type electron-emitting device is applied.

[0008]

The image forming apparatus described above,
In particular, in order to maintain stable operation for a long period of time, it is necessary to maintain a high vacuum in the image forming apparatus, particularly in the vicinity of the electron emitting element (electron emitting portion).

In view of the above, an object of the present invention is to maintain a high vacuum particularly in the vicinity of an electron-emitting device (electron-emitting portion) of an image forming apparatus.

Conventionally, as a technique for maintaining such an image forming apparatus in a high vacuum, an alloy containing Ba as a main component is energized or heated at a high frequency to form a vapor deposition film (getter film) on the inner wall of a vacuum vessel. Have been done.

In such a case, as shown in FIG. 22, the position of the Ba getter film is limited to the end (outside the display area) of the image forming apparatus because it causes a short circuit between wirings and electrodes. Was. Further, in the flat plate type image forming apparatus, since the volume of the vacuum part in the apparatus is small, the exhaust conductance from the getter outside the display area becomes insufficient. In particular, in a large area flat plate type image forming apparatus, there is a problem that sufficient exhaust cannot be performed for local degassing in the apparatus.

Recently, there has been proposed a method of maintaining a high vacuum by disposing a non-evaporable getter in an image display area in a vacuum container. However, in these non-evaporable getter configurations, it has been difficult to say that the manufacturing method is difficult or that the effects are sufficiently achieved.

For example, Japanese Patent Application Laid-Open No. Hei 4-12436 discloses a method of forming a gate electrode with a getter material in an electron source having a gate electrode for extracting an electron beam. Manufacturing of chips, bonding of semiconductors, and the like require complicated steps in a vacuum, and there is a limit to a manufacturing apparatus for increasing the size.

Also, the method of forming a getter material on an anode plate disclosed in US Pat. No. 5,453,659 requires electrical insulation between the getter material and the phosphor, and requires a precise method. For microfabrication, it is created by repeatedly performing patterning by photolithography technology.
Therefore, the process becomes complicated, and the size of the image forming apparatus that can be manufactured is limited by the size of the apparatus used for photolithography.

The method using a metal back or a wiring as a getter disclosed in Japanese Patent Application Laid-Open No. 7-322021 is preferable in that it can be formed by a simple manufacturing method and can be applied to a large area. Has limitations on the thickness and material (atomic number) of the getter film due to electron beam transmission, and has limitations on its area when applied to wiring.

An object of the present invention is to provide a new image forming apparatus which solves the above-mentioned problems of the prior art.

[0017]

The above object is achieved by the following means.

That is, according to the present invention, there is provided an electron source substrate, an image forming member disposed to face the electron source substrate, and an image forming member disposed between the electron source substrate and the image forming member.
An image forming apparatus having a metal plate having an electron passage hole through which electrons emitted from the electron source substrate pass, wherein the metal plate having the electron passage hole has a getter material. An electron source substrate, an image forming member disposed to face the electron source substrate in an envelope, and the electron source between the electron source substrate and the image forming member. In an image forming apparatus having a metal plate having an electron passage hole through which electrons emitted from a substrate pass, the metal plate having the electron passage hole has a surface facing the image forming material mainly composed of a low secondary electron emission material. A metal plate having an electron passage hole, wherein a surface facing the electron source substrate has a getter material, and a surface facing the image forming member. Is low secondary Be constituted by coating mainly children release material, a metal plate having the electron passing hole,
The surface facing the electron source substrate has a getter material, and the surface facing the image forming member is formed of a coating mainly composed of a low secondary electron emission material, and the metal plate having the electron passage holes is The metal base material and the surface of the metal base material facing the electron source substrate have a coating having a getter material, and the surface of the metal base material facing the image forming member is mainly composed of a low secondary electron emission material. The getter material is made of Ti, Z
r, or an alloy mainly containing at least one of them, the getter material is V, Fe, Al or an alloy mainly containing at least one of them, and a center of the electron passage hole. Is arranged at a position other than immediately above the electron emitting portion of the electron source substrate, the electron source substrate is composed of a plurality of electron-emitting devices, the electron source substrate, a plurality of cold cathode type electron-emitting devices It is connected to the electrically insulated X-direction wiring and the Y-direction wiring,
The image forming member is located at a distance D from the electron source substrate, an electron acceleration voltage Va is applied, the metal plate having the electron passage holes is located at a distance d from the electron source substrate,
A potential regulating plate to which a constant voltage Vc = <Vaxd / D is applied, wherein the electron source substrate has a plurality of rows of electron-emitting devices in which both ends of each of the plurality of electron-emitting devices are connected by wiring; The metal plate having the electron passage holes is used as a means for modulating an electron beam, the electron emitting element is a cold cathode electron emitting element, and the cold cathode type electron emitting element is a surface conduction type electron emitting element. In some embodiments, the secondary electron emitting material is carbon.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below in more detail.

(Embodiment 1) An example of a preferred embodiment of the present invention will be described with reference to FIG.

The image forming apparatus according to the present embodiment is an image forming member to which an electron source substrate comprising the aforesaid thermionic emission device or the cold cathode electron emission device and an electron acceleration voltage Va located at a distance D from the electron source substrate are applied. And a metal plate having an electron passage hole having a getter material located at a distance d from the electron source.

In the present embodiment, the metal plate having the electron passing holes is an image forming apparatus having a configuration in which a constant voltage Vc = <Vaxd / D is applied and used as a potential regulating plate.

FIG. 1 shows a display panel 1000 used in this embodiment.
FIG. 2 is an external perspective view of FIG. 1, with a part of the panel cut away to show the internal structure. FIG. 4 is an enlarged sectional view showing a part of the display panel of FIG.

In FIG. 1, reference numeral 110 denotes an electron source substrate on which a plurality of electron-emitting devices are arranged; 81, a rear plate on which the electron source substrate 110 is fixed; 86, an image of a fluorescent film 84 and a metal back 85 on the inner surface of a glass substrate 83; A face plate on which a forming member is formed, 101 is a control electrode used in an image forming apparatus using a thermionic emission device, or an electron passage of the potential regulation plate or the like applied to an image forming device using a cold cathode electron emission device. A metal plate having holes, 102 is an electron passage hole,
It is.

Reference numeral 82 denotes a support frame.
The rear plate 81 and the face plate 86 are joined by using a low melting point frit glass or the like to form an airtight container for maintaining a vacuum.

As shown in FIG. 4, reinforcing spacers 109 are provided between the metal plate having the electron passing holes and the face plate and / or between the metal plate having the electron passing holes and the electron source substrate. Is also good. Further, when an electron-emitting device is used, a control electrode may be provided between the metal plate and the face plate.

Here, Va, Vc, D and d are appropriately set according to the configuration of the image forming apparatus. For example, Va is several hundred V to several tens kV, D is several hundred μm to several tens mm, d is several tens μm to several mm, and Vc is Vc = <Vaxd / D
Is set in the range.

<Metal Plate Having Electron Passing Holes> The electron passing holes are provided for each electron emitting element of the electron source or one of the image forming members.
For pixel and color display, one for each RGB phosphor
In this case, the shape of the electron passage hole can be rectangular, circular, elliptical, etc.
The size depends on the pixel size, but it is several tens to several hundreds of u.
m. Alternatively, a large number of passage openings may be provided in a mesh shape as openings. The thickness a of the metal plate having the electron passage holes can be 0.1 to 0.3 mm.

In the present invention, the metal plate (that is, the potential regulating plate) 101 having the electron passing holes has a getter material.

As the getter material, metals such as Ti, Zr, Hf, V, Nb, Ta, W and the like, which are non-evaporable getter materials, and alloys thereof can be used. The alloy may contain Al, Fe, Ni, or the like.

A metal plate having electron passing holes is shown in FIG.
As shown in FIG. 3B, it may be constituted by the getter material 131 itself, or as shown in FIG. 3C), a structure in which a coating 133 made of the getter material is provided on an appropriate metal base material 132. The thickness of the film made of the getter material is not particularly limited, but may be several hundreds.
It is preferable that the surface area be as large as possible from the viewpoint of the total amount of adsorption. Especially,
In the configuration as shown in FIG. 3A, a getter material is arranged so as to face a phosphor as an image forming material, and it is possible to remove gas emitted from the phosphor due to irradiation with an electron beam.

Further, as shown in FIGS. 3B and 3C, a conductive film 134 whose main component is a secondary electron emission material lower than that of the metal plate may be provided on the surface facing the image forming member. Desirable, and particularly preferred are carbon and graphite. In this way, when irradiation with ions or electrons scattered from the image forming member side is performed,
The emission amount of secondary electrons and reflected electrons can be reduced.
The thickness of carbon is several hundred nm to several hundred μm.

Normally, a non-evaporable getter requires activation of the getter, but in the image forming apparatus of the present invention, activation of the getter is performed by external heating or electric heating of a metal plate having electron passing holes. Alternatively, when a surface-conduction electron-emitting device is used as the electron-emitting device, for example, the voltage applied between the device electrodes is changed, or the voltage is changed and the metal plate is applied. The irradiation may be performed by irradiating an electron beam emitted from the electron-emitting device by changing the potential. When the getter surface is irradiated with an electron beam of about Vc during operation, diffusion of the adsorbed molecules to the getter material is promoted, and a clean surface can be always maintained.

A metal plate (ie, a potential regulating plate) 101 having an electron passage hole has a constant voltage Vc of Vc <= Vaxd / D.
Apply c. As a result, the equipotential near the electron passage hole is curved as shown in FIG. 4, and electrons that have flown in the direction of the spacer 109 receive an inner force F near the electron passage hole.
The trajectory is bent as shown. As the spacer, an insulating material, a material obtained by coating an insulating material with a high-resistance film, or the like can be used. An electron lens is thus formed on the potential regulating plate between the image forming member and the auxiliary electrode to prevent collision of the electron beam with the spacer, reduce charge-up, and converge the electron beam onto the image forming member. Also has the effect of improving. In addition, the potential regulating plate has a function of preventing damage caused by collision of the positive ions generated in vacuum with the electron source.

When a surface conduction electron-emitting device is employed as the electron-emitting device in this embodiment, the electrons emitted from the surface conduction electron-emitting device 74 have horizontal components as shown in FIG. Because it has the feature of having
The electron passage holes 102 can be arranged so as to be shifted from immediately above the electron emission section 5. That is, the center of the electron passage hole can be arranged at a position other than immediately above the electron emission portion 5. In such a configuration, as can be seen from the drawing, a getter can be arranged immediately above (or almost immediately above) the electron emitting section 5, and therefore, a more preferable configuration from the viewpoint of maintaining a high vacuum in the vicinity of the electron emitting section. Becomes The amount of shift between the electron passing hole and the portion immediately above the electron emitting portion depends on d, Vc, Va, and the like, and is appropriately designed, but is about 1 μm to several hundred μm.

<Image forming member> The image forming member is a fluorescent film,
It is composed of metal back, black stripe, etc.

FIG. 9 is a schematic diagram showing a fluorescent film. The fluorescent film 84 can be composed of only a phosphor in the case of monochrome. In the case of a color fluorescent film, it can be composed of a black conductive material 91 called a black stripe or a black matrix and a fluorescent material 92 depending on the arrangement of the fluorescent materials. The purpose of providing the black stripes and the black matrix is to make the mixed portions inconspicuous by making the painted portions between the phosphors 92 of the necessary three primary color phosphors black in the case of color display, An object of the present invention is to suppress a decrease in contrast due to light reflection. As the material of the black stripe, a material having conductivity and having little light transmission and reflection can be used in addition to a material mainly containing graphite which is generally used.

As a method of applying the fluorescent substance to the glass substrate 93, a precipitation method, a printing method, or the like can be adopted regardless of monochrome or color. Usually, a metal back 85 is provided on the inner surface side of the fluorescent film 84. The purpose of providing a metal back is
The light emitted from the phosphor toward the inner surface is converted into a face plate 8.
Improve the brightness by specular reflection on the 6 side, act as an electrode for applying electron beam acceleration voltage, protect the phosphor from damage due to collision of negative ions generated in the envelope, etc. It is. The metal back performs a smoothing process (usually called “filming”) on the inner surface of the phosphor film after the phosphor film is formed,
Thereafter, it can be manufactured by depositing Al using vacuum evaporation or the like.

The face plate 86 is further provided with a fluorescent film 8.
A transparent electrode (not shown) may be provided on the outer surface side of the fluorescent film 84 in order to increase the conductivity of the phosphor film 84.

<Electron Source> Various types of electron sources can be adopted. When a cold cathode electron emission device is used as the electron emission device, an electron source having a simple matrix arrangement is given as an example.

An electron source substrate having a simple matrix arrangement will be described with reference to FIG. In FIG. 7, 171 is an electron source substrate, 172 is an X-direction wiring, and 173 is a Y-direction wiring. 174 is an electron-emitting device, and 175 is a connection. As shown in the figure, the simple matrix arrangement means that the electron-emitting devices are X
A plurality of electron emission elements arranged in a matrix in the direction and the Y direction, one of the electrodes of the plurality of electron emission elements arranged in the same row are commonly connected to a wiring in the X direction, and The other electrode of the element is commonly connected to the wiring in the Y direction.

As the electron-emitting device, FIGS.
0, a surface conduction electron-emitting device, a Spindt-type electron-emitting device, a MIM-type electron-emitting device, or the like can be employed. As described above, as shown in FIG. 5, especially in the case of the surface conduction type electron-emitting device, the getter can be disposed immediately above or almost immediately above the electron-emitting portion, so that the degassing generated during the operation is performed. Can be effectively adsorbed, and the effect is great.

FIG. 21 is a diagram schematically showing the relationship between the emission current Ie, the device current If, and the device voltage Vf of the surface conduction electron-emitting device. In FIG. 21, since the emission current Ie is significantly smaller than the element current If, it is shown in arbitrary units. The vertical and horizontal axes are linear scales.

As is clear from FIG. 21, the surface conduction electron-emitting device has three characteristic properties with respect to the emission current Ie.

(I) When an element voltage higher than a certain voltage (referred to as a threshold voltage, Vth in FIG. 21) is applied to the present element, the emission current Ie rapidly increases, while the threshold voltage V
Below th, the emission current Ie is hardly detected. That is, it is a nonlinear element having a clear threshold voltage Vth with respect to the emission current Ie.

(Ii) Since the emission current Ie depends monotonically on the device voltage Vf, the emission current Ie can be controlled by the device voltage Vf.

(Iii) The emission charge captured by the anode electrode depends on the time during which the device voltage Vf is applied. That is,
The amount of charge captured by the anode electrode 54 is equal to the device voltage Vf
Can be controlled by the application time.

The X direction wiring 172 includes Dox 1 and Dox
2, a scanning signal applying unit (not shown) for applying a scanning signal for selecting a row of the electron-emitting devices 174 arranged in the X direction is connected through the external terminal 112 made of Doxm. On the other hand, Doy1, Doy1,
A modulation signal generating means (not shown) for modulating each row of the electron-emitting devices 174 arranged in the Y direction in accordance with an input signal is connected through an external terminal 113 made of Doyn. The driving voltage applied to each electron-emitting device is supplied as a difference voltage between a scanning signal and a modulation signal applied to the device.

In the above configuration, individual elements can be selected and driven independently using simple matrix wiring.

In the present image display device having such a configuration, electron emission is generated by applying a voltage to each electron-emitting device via the external terminals Dox1 to Doxm and Doy1 to Doyn. A high voltage is applied to the metal back 85 or a transparent electrode (not shown) via the high voltage terminal Hv to accelerate the electron beam. The accelerated electrons collide with the fluorescent film 84 and emit light to form an image.

By arranging a metal plate having an electron passage hole made of a getter material, a sufficient getter area can be arranged in the vicinity of the electron-emitting device. Can be kept.

Further, a constant voltage Vc = <Vaxd / D is applied to the metal plate having the electron passage holes, and acts as a potential regulating plate.

(Embodiment 2) Next, an example of another embodiment of the present invention will be described with reference to FIG.

In the image forming apparatus of this embodiment, similarly to the first embodiment, the electron source and the image forming member to which the electron acceleration voltage Va located at a distance D from the electron source is applied and the distance d from the electron source to the electron source. It is constituted by a metal plate having an electron passage hole having a located getter material.

In this embodiment, the image forming apparatus has a configuration in which a plurality of metal plates having the above-mentioned electron passage holes are arranged for each row and used to modulate the electron beam emitted from the electron-emitting device. That is, a metal plate having an electron passage hole is used as a control electrode (or called a grid electrode).

In FIG. 2, reference numeral 120 denotes a metal plate having an electron passage hole (that is, a grid electrode), 121 denotes an electron passage hole, and 122 denotes an external terminal formed of Dox1, Dox2,... Doxm. 123 is a terminal outside the container composed of G1, G2,... Gn connected to the grid electrode 120;
0 is an electron source substrate. In FIG. 2, the same portions as those shown in FIG. 1 are denoted by the same reference numerals as those shown in these drawings.

Va, D, and d differ depending on the configuration of the image forming apparatus. For example, Va is 5 to 20 kV, and D is 1 to 20 kV.
About 10 mm, d is in the range of about 0.1 mm to several mm,
Is set.

In the present invention, the metal plate 120 having the electron passage holes is provided with a getter material as in the first embodiment.

Outer container terminal 122 and grid outer terminal 123 connected to metal plate 120 having electron passage holes
Are electrically connected to a control circuit (not shown).

As the electron source, various ones can be adopted. One example is an electron source of a ladder type arrangement.

FIG. 8 is a schematic diagram showing an example of a ladder-type electron source. 8, 180 is an electron source substrate,
181 is an electron-emitting device. 182, Dx1 to Dx1
Reference numeral 0 denotes a common wiring for connecting the electron-emitting devices 181. A plurality of electron-emitting devices 181 are arranged on the substrate 180 in parallel in the X direction (this is called an element row).
A plurality of the element rows are arranged to constitute an electron source.
That is, each of a large number of electron-emitting devices arranged in parallel is connected at both ends, and a large number of rows of electron-emitting devices are arranged to form a ladder-type electron source.

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 is applied to an element row that wants to emit an electron beam, and a voltage equal to or lower than the electron emission threshold is applied to an element row that does not emit an electron beam. Common lines Dx2 to Dx9 between the element rows are, for example, Dx2, Dx
3 can be the same wiring.

The common wirings Dx1 to Dx10 are electrically connected to a control circuit (not shown) via terminals Dox1, Dox2,... Doxm outside the container.

The other components of the image forming apparatus are the same as in the first embodiment.

In the image forming apparatus of this embodiment, a modulation signal for one line of an image is simultaneously applied to the grid electrode rows in synchronization with the sequential driving (scanning) of the element rows one by one. This makes it possible to control the irradiation of each electron beam to the phosphor and display an image one line at a time.

By arranging a metal plate having an electron passage hole made of a getter material, a sufficient getter area can be arranged in the vicinity of the electron-emitting device, and in particular, good vacuum can be maintained in the vicinity of the electron-emitting portion. it can. Incidentally, also in this embodiment,
Carbon on the surface facing the image forming material as described above,
In some cases, a conductive film mainly composed of a secondary electron emission material lower than a metal plate such as graphite is formed.

The image forming apparatus of the present invention can be used as an image forming apparatus as an optical printer including a photosensitive drum or the like in addition to a display device for a television broadcast, a video conference system, a computer, or the like. Can also be used.

[0068]

EXAMPLES Hereinafter, the present invention will be described in detail with reference to specific examples, but the present invention is not limited to these examples, and each element within a range in which the object of the present invention is achieved. And those in which the design has been replaced or changed.

(Examples 1, 2, and 3) FIG. 11 is an external perspective view of a display panel 1100 used in this example, in which a part of the panel is cut away to show the internal structure.

The image forming apparatus of this embodiment is located at a distance of about 5 mm from the electron source 171 in which the surface conduction electron-emitting devices 74 are arranged in a simple MTX according to the first embodiment, and the electron acceleration voltage Va = This is an example in which the image forming member 87 to which 10 kV is applied and a metal plate 101 having an electron passage hole 102 having a getter material located at a distance of about 100 μm from the electron source.

In this embodiment, the metal plate having the electron passing holes is an image forming apparatus having a configuration in which a constant voltage Vc of about 375 V is applied and used as a potential regulating plate. The pixel size was about 400 μm × 600 μm, the electron passage hole was rectangular, and the size was about 100 μm × 200 μm. The thickness a of the metal plate having the electron passing holes was about 0.1 mm.

One electron passage hole is provided for each electron-emitting device of the electron source.

In FIG. 11, reference numeral 81 denotes an electron source substrate 171.
A rear plate 86 fixed with the image forming member 87 such as a fluorescent film 84 and a metal back 85 on the inner surface of the glass substrate 83
Is formed on the face plate.

Reference numeral 82 denotes a support frame. The rear frame 81 and the face plate 86 are joined to the support frame by using a low melting point frit glass or the like in a sealing step described later to maintain a vacuum. Forming an airtight container.

In the first embodiment, as shown in FIG. 3A), the metal plate having the electron passing holes is made of Zr-
It was composed of a V-Fe alloy.

As Example 2, as shown in FIG. 3B), the metal plate having the electron passing holes in Example 1 was further coated with a conductive film mainly composed of carbon on the surface facing the image forming member. An arrangement of 5 μm was constructed.

As Comparative Example 1, a metal plate having electron passing holes was composed of Ni alone.

As Example 3, as shown in FIG. 3B), the metal plate having the electron passing holes in Comparative Example 1 was further provided with a conductive film containing carbon as a main component on the surface facing the image forming member by about 5 μm. What was constructed.

Outside the image display area, a Ba evaporation type getter (not shown) was arranged as in the image forming apparatus of FIG.

* Manufacturing Method An example of the manufacturing method of the display panel of this embodiment will be described below.

FIG. 10 shows a flowchart of a method for manufacturing the image forming apparatus of the present embodiment.

1) Formation of Electron Source Substrate An electron source having a surface conduction electron-emitting device arranged in a simple MTX arrangement was prepared as an electron source.

FIG. 18 is a schematic diagram showing the structure of a surface conduction electron-emitting device. In FIG. 18, 1 is a substrate, 2 and 3
Denotes an element electrode, 4 denotes a conductive thin film, and 5 denotes an electron emitting portion.
Regarding its basic configuration and manufacturing process,
No. 235255. In this embodiment, a blue plate substrate, a device electrode made of Pt having a thickness of 30 nm, and a conductive thin film of PdO having a thickness of about 10 nm were used as the substrate.

2) Formation of Light Emitting Display Panel (Face Plate) As a method of applying a fluorescent substance to the glass substrate 83, a slurry method or the like was used. Further, a metal back 85 is provided on the inner surface side of the fluorescent film 84. The metal back performs a smoothing process (usually called filming) on the inner surface of the fluorescent film after the fluorescent film is formed, and thereafter, It can be produced by vacuum deposition of Al. In the face plate 86, a transparent electrode (not shown) is arranged on the outer surface side of the fluorescent film 84 in order to further enhance the conductivity of the fluorescent film.

3) Formation of Metal Plate Having Electron Passing Holes and Other Members Getter material Zr-V-Fe alloy (for example, St707 Getters St707) was used as the metal plate having electron passing holes.

As the conductive film mainly containing carbon in Example 2, Hitachi Powder Metallurgy HITASOL GA-37 was used.

4) Sealing The above-mentioned electron source substrate, rear plate, light emitting display panel, metal plate having electron passing holes, and the like are arranged via a support frame and a spacer. Frit glass was applied to joints such as a face plate, a support frame, and a rear plate, and sealed by baking in a nitrogen atmosphere to form an envelope as shown in FIG.

5) Exhaust The atmosphere in the glass container completed as described above is exhausted by a vacuum pump through an exhaust pipe (not shown).

FIG. 13 is a schematic diagram showing an outline of an apparatus used in this step and thereafter. Image forming apparatus 1131
Is connected to a vacuum chamber 1133 via an exhaust pipe 1132 and further connected to an exhaust device 1135 via a gate valve 1134. Vacuum chamber 1133
In order to measure the internal pressure and the partial pressure of each component in the atmosphere, a pressure gauge 1136 and a quadrupole mass analyzer 1137 are used.
Etc. are attached. Since it is difficult to directly measure the pressure inside the envelope 1188 of the image display device 1131, the pressure inside the vacuum chamber 1133 is measured to control the processing conditions.

A gas introduction line 1138 is connected to the vacuum chamber 1133 in order to introduce necessary gas into the vacuum chamber to control the atmosphere. An introduction substance source 1140 is connected to the other end of the gas introduction line 1138, and the introduction substance is stored in an ampule or a cylinder. In the middle of the gas introduction line, an introduction control means 1 for controlling a route for introducing an introduced substance.
139 are provided. As the introduction amount control means, specifically, a valve such as a slow leak valve capable of controlling the flow rate to be released, a mass flow controller, or the like can be used according to the type of the substance to be introduced.

5) Forming Subsequently, a forming step is performed. As an example of a method of the forming step, a method by an energization process will be described. When power is applied between the device electrodes 4 and 5 using a power supply (not shown) via the wiring, the electron-emitting portion 5 having a changed structure is formed at the portion of the conductive thin film 3. According to the energization forming, a portion of the conductive thin film 3 where a structure such as destruction, deformation or alteration is locally changed is formed. This portion constitutes the electron emission section 5.

At this time, for example, as shown in FIG. 14, the Y-direction wiring 1173 is connected to the common electrode 1141, and the element connected to one of the X-direction wirings 1172 is connected to the power supply 1142.
Accordingly, forming can be performed by applying a voltage pulse at the same time. Conditions such as the shape of the pulse and the determination of the end of the processing may be selected according to the above-described method for forming the individual elements. In addition, by sequentially applying (scrolling) a pulse with a phase shifted to a plurality of X-direction wirings, it is possible to form elements connected to the plurality of X-direction wirings collectively. In the figure, reference numeral 1143 denotes a current measuring resistor, and 1144 denotes an oscilloscope for measuring current.

6) Activation An activation process is performed on the formed element, and carbon and a carbon compound are deposited on the electron-emitting portion and in the vicinity thereof.

After sufficiently exhausting the inside of the envelope, the organic substance is introduced from the gas introduction line 1138. Organic substances include alkanes, alkenes, aliphatic hydrocarbons of alkynes, aromatic hydrocarbons, alcohols, aldehydes,
Examples thereof include ketones, amines, organic acids such as phenol, carboxylic acid, and sulfonic acid. Specific examples include saturated hydrocarbons represented by C _n H _{2n + 2} such as methane, ethane, and propane, ethylene, and propylene. Unsaturated hydrocarbons represented by a composition formula such as C _n H _2n , benzene, benzonitrile, trinitrile, toluene, methanol, ethanol, formaldehyde, acetaldehyde, acetone,
Methyl ethyl ketone, methylamine, ethylamine, phenol, formic acid, acetic acid, propionic acid and the like can be used.
Alternatively, first, the gas is evacuated by an oil diffusion pump or a rotary pump, whereby the organic substance remaining in the vacuum atmosphere can be used.

Further, substances other than organic substances may be introduced as necessary. By applying a voltage to each electron-emitting device in an atmosphere containing an organic substance formed in this manner, carbon or a carbon compound, or a mixture of both, is deposited on the electron-emitting portion, and the amount of emitted electrons is drastic. To rise.

In this embodiment, the organic substance is benzonitrile, and the indicated value of the pressure gauge 136 is 5 × 10 ⁻⁶ to
rr.

At this time, the voltage was applied by simultaneously applying a voltage pulse of about 10 to 16 V to the element connected to one direction wiring by the same connection as in the above-described forming.

7) Stabilization / Baking This step is a step of exhausting organic substances in the vacuum vessel.

It is preferable that the entire vacuum vessel is heated / baked to evacuate the inside of the vacuum vessel so that the organic substance molecules adsorbed on the inner wall of the vacuum vessel and the electron-emitting device are easily evacuated. The heating condition at this time is desirably performed at 100 to 300 ° C. for a longer time, but is not particularly limited to this condition, and is appropriately selected depending on various conditions such as the size and shape of the vacuum vessel and the configuration of the electron-emitting device. Perform according to conditions.

By this step, the pressure in the vacuum section in the envelope is evacuated to about 1 × 10 ⁻⁸ Torr.

It is preferable to use a vacuum-evacuation 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.

In this embodiment, baking was performed at 300 ° C. for 10 hours.

The getter material applied as a metal plate having electron passing holes according to the present embodiment is heated by this baking step.
Activated to have adsorption capacity.

8) Ba Getter Flash A Ba getter disposed at a predetermined position (not shown) in the envelope 1188 is heated at a high frequency to form a deposited film.

9) Sealing An unillustrated exhaust pipe is welded by heating with a gas burner to seal the envelope.

* Connection of Driving Circuit The following driving circuit was connected to the display panel having the above configuration, and television display was performed.

An example of the configuration of a driving circuit for performing television display will be described with reference to FIG. 15, 1101 is an image display panel, 1102 is a scanning circuit,
1103 is a control circuit, and 1104 is a shift register. 1105 is a line memory, 1106 is a synchronization signal separation circuit, 1107 is a modulation signal generator, and Vx and Va are DC voltage sources.

The display panel 1101 includes terminals Dox1 to Doxm, terminals Doy1 to Doyn, and a high voltage terminal H.
It is connected to an external electric circuit via v. Terminal Dox
Scans for sequentially driving electron sources provided in the display panel, that is, a group of surface conduction electron-emitting devices arranged in a matrix of M rows and N columns, one by one (N elements) are provided in 1 to Doxm. A signal is applied.

To the terminals Dy1 to Dyn, 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. The high-voltage terminal Hv is connected to the DC voltage source Va, for example, by one.
A DC voltage of 0 kV is supplied, which is an accelerating voltage for applying sufficient energy to the electron beam emitted from the surface conduction electron-emitting device to excite the phosphor.

Next, the scanning circuit 1102 will be described. This circuit includes M switching elements inside (in the drawing, S1 to Sm are schematically shown).
Each switching element selects either the output voltage of the DC voltage source Vx or 0 [V] (ground level), and is electrically connected to the terminals Dx1 to Dxm of the display panel 1101. Each of the switching elements S1 to Sm operates based on a control signal Tscan output from the control circuit 1103, and can be configured by combining switching elements such as FETs, for example.

In the case of the present embodiment, the DC voltage source Vx uses a driving voltage applied to an element that is not scanned based on the characteristics (electron emission threshold voltage) of the surface conduction type electron emission element. It is set to output a constant voltage that is equal to or lower than the voltage.

The control circuit 1103 has a function of matching the operation of each unit so that an appropriate display is performed based on an image signal input from the outside. The control circuit 1103
Synchronization signal Tsy sent from synchronization signal separation circuit 1106
Tscan and Tsf for each part based on nc
The control signals t and Tmry are generated.

The synchronizing signal separation circuit 1106 is a circuit for separating a synchronizing signal component and a luminance signal component from an NTSC television signal input from the outside, and uses a general frequency separation (filter) circuit or the like. Can be configured. The synchronization signal separated by the synchronization signal separation circuit 1106 is composed of a vertical synchronization signal and a horizontal synchronization signal, but is shown here as a Tsync signal for convenience of explanation. The luminance signal component of the image separated from the television signal is referred to as a DATA signal for convenience. The DATA signal is input to the shift register 1104.

The shift register 1104 is for serially / parallel-converting the DATA signal input serially in time series for each line of an image, and is based on a control signal Tsft sent from the control circuit 1103. (Ie, the control signal Tsft can be said to be a shift clock of the shift register 1104). The data for one line of the serial-parallel-converted image (corresponding to drive data for N electron-emitting devices) is output from the shift register 1104 as n parallel signals Id1 to Idn.

The line memory 1105 is a storage device for storing data for one line of an image for a required time, and stores the contents of Id1 to Idn as appropriate according to a control signal Tmry sent from the control circuit 1103. The stored contents are output as I′d1 to I′dn and input to the modulation signal generator 1107.

The modulation signal generator 1107 is a signal source for appropriately driving and modulating each of the surface conduction electron-emitting devices according to each of the image data I'd1 to I'dn.
The output signal is applied to the surface conduction electron-emitting device in the display panel 1101 through the terminals Doy1 to Doyn.

As described above, the electron-emitting device to which the present invention can be applied has the following basic characteristics with respect to the emission current Ie. That is, a clear threshold voltage Vth is required for electron emission.
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 device. From this, when applying a pulsed voltage to this element,
For example, when a voltage lower than the electron emission threshold is applied, electron emission does not occur, but when a voltage higher than the electron emission threshold is applied, an electron beam is output. At this time, the pulse peak value V
By changing m, the intensity of the output electron beam can be controlled. In addition, 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 according to the input signal, a voltage modulation method, a pulse width modulation method, or the like can be adopted. In implementing the voltage modulation method, a circuit of a voltage modulation method that generates a voltage pulse of a fixed length and modulates the peak value of the pulse appropriately according to input data is used as the modulation signal generator 1107. be able to.

When implementing the pulse width modulation method,
As the modulation signal generator 1107, a pulse width modulation circuit that generates a voltage pulse having a constant peak value and appropriately modulates the width of the voltage pulse according to input data can be used.

The shift register 1104 and the line memory 1
The digital signal 105 and the analog signal 105 can be used. This is because the serial / parallel conversion and storage of the image signal may be performed at a predetermined speed.

When the digital signal type is used, it is necessary to convert the output signal DATA of the synchronization signal separation circuit 1106 into a digital signal.
What is necessary is just to provide a D converter. In this connection, the circuit used for the modulation signal generator 1107 is slightly different depending on whether the output signal of the line memory 1105 is a digital signal or an analog signal. That is, in the case of the voltage modulation method using a digital signal, for example, a D / A conversion circuit is used as the modulation signal generator 1107, and an amplification circuit and the like are added as necessary. In the case of the pulse width modulation method, the modulation signal generator 11
For 07, for example, a circuit combining a high-speed oscillator and a counter (counter) for counting the number of waves output from the oscillator and a comparator (comparator) for comparing the output value of the counter with the output value of the memory is used. 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 can be added.

In the case of the voltage modulation method using an analog signal, an amplification circuit using, for example, an operational amplifier can be used as the modulation signal generator 1107, and a level shift circuit and the like can be added as necessary. In the case of the pulse width modulation method, for example, a voltage controlled oscillator (VCO)
And, if necessary, an amplifier for amplifying the voltage up to the driving voltage of the surface conduction electron-emitting device can be added.

In the image display device of the present invention which can take such a configuration, each of the electron-emitting devices is provided with an external terminal Do.
By applying a voltage via x1 to Doxm and Doy1 to Doyn, electron emission occurs. High voltage terminal H
A high voltage is applied to the metal back 85 or a transparent electrode (not shown) via v to accelerate the electron beam. The accelerated electrons collide with the fluorescent film 84 and emit light to form an image.

The configuration of the image forming apparatus described here is an example of an image forming apparatus to which the present invention can be applied, and various modifications can be made based on the technical idea of the present invention. As for the input signal, the NTSC system has been described, but the input signal is not limited to this, and the PAL, SECAM system, etc.
A TV signal composed of a larger number of scanning lines (for example, M
A high-definition TV) system such as the USE system can also be adopted.

* Evaluation FIG. 16 is a diagram showing a change in luminance when the image forming apparatuses of the first and second embodiments and the comparative example are operated for a long time.

As can be seen from the figures, the first and second embodiments are different.
As a result, the image forming apparatus of the first embodiment was able to suppress a decrease in luminance when operated for a long time as compared with the comparative example.

Further, compared to the first embodiment, the metal plate having an electron passage hole on the image forming member side of the second embodiment is made of carbon, which is a material having less secondary electrons and reflected electrons. Furthermore, the discharge was small and the display image quality was excellent. Further, as a similar effect, Example 3 has less discharge compared to Comparative Example 1 and is excellent in a displayed image.

(Embodiment 4) FIG. 12 is an external perspective view of a display panel 2100 used in this embodiment, in which a part of the panel is cut away to show the internal structure.

The image forming apparatus of this embodiment is located at a distance of about 5 mm from the electron source 180 in which the surface conduction electron-emitting device 74 is arranged in a ladder shape according to the second embodiment, and the electron acceleration voltage Va = Image forming member 87 to which 10 kV is applied
And a metal plate 120 having an electron passage hole 121 having a getter material located at a distance of about 100 μm from the electron source.

Reference numeral 122 denotes Dox1, Dox2,... Doxm
This is a terminal outside the container. 123 is a grid electrode 1
., Gn connected to 20. In FIG. 12, the same parts as those shown in FIG. 11 are denoted by the same reference numerals as those shown in these figures.
The outer container terminal 122 and the grid outer terminal 123 connected to the metal plate 120 having the electron passage hole are electrically connected to a control circuit (not shown) via the outer container terminal.

In the present embodiment, the metal plate having the above-mentioned electron passing holes is an image forming apparatus having a configuration in which a plurality of metal plates are arranged for each row and used to modulate the electron beam emitted from the electron-emitting device. That is, a metal plate having an electron passage hole is used as a control electrode (or called a grid electrode).

The pixel size is about 400 μm × 600 μm,
The electron passage hole was circular and had a diameter of 150 μm, and the center of the hole was shifted by 80 μm from immediately above the electron emission portion. The thickness a of the metal plate having electron passing holes is about 0.2 m
m. One electron passage hole was provided for each electron-emitting device of the electron source.

As shown in FIG. 3c), a metal plate having electron passing holes according to the third embodiment is made of a metal base material made of Ni and Zr-Al (for example, ST121 manufactured by Saes Getters) as a getter material on the surface on the electron source side. The coating was applied on the order of 100 μm. Further, a graphite coating of about 5
μm.

Further, as Comparative Example 2, a metal plate having electron passing holes was made of Fe alone.

A Ba deposition type getter (not shown) was arranged outside the image display area similarly to the image forming apparatus of FIG.

The manufacturing method of the image forming apparatus of this embodiment is the same as that of the first embodiment.
According to the manufacturing method.

However, after the baking step, a voltage is applied to both ends of the metal plate having the electron passing holes, a current is applied, and heating is performed at about 600 ° C. to activate the getter material of the metal plate having the electron passing holes. The getter material was activated.

In the image forming apparatus of this embodiment, a modulation signal for one line of an image is simultaneously applied to the grid electrode rows in synchronization with sequentially driving (scanning) the ladder-type electron source element rows one by one. This makes it possible to control the irradiation of each electron beam to the phosphor and display an image one line at a time.

* Evaluation FIG. 17 is a diagram showing a change in luminance when the image forming apparatuses of Example 4 and Comparative Example were operated for a long time.

As can be seen from the figure, the image forming apparatus according to the third embodiment was able to suppress a decrease in luminance when operated for a long time as a result as compared with the comparative example 2. Further, in the third embodiment, the surface of the metal plate having the electron passage holes on the image forming member side is made of carbon, which is a material having a small amount of secondary electrons and reflected electrons, so that the discharge frequency is low and the display image quality is low. Excellent.

[0141]

According to the present invention, a metal plate having an electron passage hole through which electrons pass and having a getter material is disposed between an electron source and the image forming member, thereby enabling a local device in the apparatus to be provided. Image-forming members in the vicinity of the electron-emitting device, which is a gas-emitting portion, and to which electrons emitted from the electron-emitting device are irradiated. Can be suppressed, and as a result, a decrease in luminance when the device is operated for a long time can be suppressed.

In addition, since the surface of the metal plate having the electron passing holes on the image forming member side is made of carbon, graphite or the like, which is a material having a small amount of secondary electrons and reflected electrons, the discharge is small and the display image quality is reduced. An excellent image forming apparatus was obtained.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating an example of a display panel of an image forming apparatus to which the present invention can be applied.

FIG. 2 is a schematic diagram illustrating an example of a display panel of an image forming apparatus to which the present invention can be applied.

FIGS. 3A to 3C are schematic diagrams showing a metal plate having an electron passage hole having a getter material of the present invention.

FIG. 4 is a schematic cross-sectional view of a display panel of the image forming apparatus of the present invention.

FIG. 5 is a diagram illustrating a configuration in which a getter material is disposed immediately above an electron emission unit.

FIG. 6 is a diagram illustrating secondary electrons generated from a surface of the metal plate having an electron passage hole on the image forming member side.

FIG. 7 is a schematic diagram showing an example of an electron source arranged in a simple matrix.

FIG. 8 is a schematic diagram illustrating an example of an electron source having a ladder arrangement.

FIGS. 9A and 9B are schematic diagrams illustrating an example of a fluorescent film.

FIG. 10 is a flowchart illustrating an example of a manufacturing process of the image forming apparatus of the present invention.

FIG. 11 is a schematic diagram illustrating a display panel of the image forming apparatus according to the first and second embodiments.

FIG. 12 is a schematic diagram illustrating a display panel of an image forming apparatus according to a third embodiment.

FIG. 13 is a schematic diagram of a vacuum exhaust device for performing an exhaust, forming, activating, and baking process of the image display device of the present invention.

FIG. 14 is a schematic diagram illustrating a connection method for forming and activating steps of the image forming apparatus of the present invention.

FIG. 15 is a block diagram illustrating an example of a driving circuit for performing display in the image forming apparatus according to an NTSC television signal.

FIG. 16 is a graph illustrating a change in luminance of the image forming apparatuses according to the first and second embodiments.

FIG. 17 is a graph illustrating a change in luminance of the image forming apparatus according to the fourth embodiment.

FIGS. 18A and 18B are schematic diagrams illustrating a surface conduction electron-emitting device. FIGS.

FIG. 19 is a schematic view showing a Spindt-type electron-emitting device.

FIG. 20 is a schematic view showing a MIM type electron-emitting device.

FIG. 21 shows emission current I for a surface conduction electron-emitting device.
e is a graph showing an example of the relationship between element current If and element voltage Vf.

FIG. 22 is a diagram illustrating an arrangement of a conventional image forming apparatus, particularly an evaporative Ba getter.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Substrate 2, 3 Element electrode 4 Conductive thin film 5 Electron emission part 74 Surface conduction type electron emission element 81 Rear plate 82 Support frame 83 Glass substrate 84 Fluorescent film 85 Metal back 86 Face plate 87 Image forming member 91 Black conductive material 92 Fluorescence Body 101 Metal plate having electron passage hole 102 Electron passage hole 109 Spacer 110 Electron source substrate 111 Electron emitting element 112 Outer container terminal made of Dox1, Dox2,... Doxm 113 Outer container terminal made of Doy1, Doy2,. Metal plate having holes 121 Electron passage holes 122 Outer container terminals formed of Dox1, Dox2,... Doxm 123 G1, G2 connected to grid electrode 131 Getter material 132 Metal base material 133 Coating made of getter material 134 Carbon as a main component Conductive coating 171 Electron source substrate 172 X direction wiring 173 Y direction wiring 174 Electron emitting element 180 Electron source substrate 182 Electron emitting element 182 Common wiring

Claims (13)

[Claims] 1. An electron source substrate in an envelope, an image forming member disposed to face the electron source substrate, and the electron source substrate disposed between the electron source substrate and the image forming member. An image forming apparatus comprising: a metal plate having an electron passage hole through which electrons emitted from an electron passage pass, wherein the metal plate having the electron passage hole has a getter material. 2. An electron source substrate in an envelope, an image forming member disposed to face the electron source substrate, and the electron source substrate interposed between the electron source substrate and the image forming member. In an image forming apparatus having a metal plate having an electron passage hole through which electrons emitted from pass through, the metal plate having the electron passage hole has a surface facing the image forming material mainly composed of a low secondary electron emission material. An image forming apparatus having a coating. 3. A metal plate having an electron passage hole, wherein a surface facing the electron source substrate has a getter material, and a surface facing the image forming member is a coating mainly composed of a low secondary electron emission material. The image forming apparatus according to claim 1 configured. 4. The metal plate having an electron passage hole has a metal base material and a coating of a surface of the metal base material facing the electron source substrate having a getter material. The image forming apparatus according to claim 1, wherein the opposing surfaces are formed of a coating mainly composed of a low secondary electron emission material. 5. The image forming apparatus according to claim 1, wherein the getter material is Ti, Zr, or an alloy mainly containing at least one of them. 6. The image forming apparatus according to claim 1, wherein the getter material is V, Fe, Al, or an alloy containing at least one of them as a main component. 7. The image forming apparatus according to claim 1, wherein a center of the electron passage hole is arranged at a position other than immediately above an electron emission portion of the electron source substrate. 8. The image forming apparatus according to claim 1, wherein said electron source substrate comprises a plurality of electron-emitting devices. 9. The electron source substrate, wherein a plurality of electron-emitting devices are connected to an X-direction wiring and a Y-direction wiring which are electrically insulated from each other, and the image forming member is at a distance from the electron source substrate. D, the electron accelerating voltage Va is applied, the metal plate having the electron passing holes is located at a distance d from the electron source substrate, and the potential regulating plate is applied with a constant voltage Vc = <Vaxd / D. The image forming apparatus according to claim 1, wherein: 10. The electron source substrate has a plurality of rows of electron-emitting devices in which both ends of each of the plurality of electron-emitting devices are connected by wiring, and the metal plate having the electron passage holes includes The image forming apparatus according to claim 1, wherein the image forming apparatus is used as a modulation unit. 11. The image forming apparatus according to claim 1, wherein said electron-emitting device is a cold cathode electron-emitting device. 12. The image forming apparatus according to claim 1, wherein said cold cathode electron-emitting device is a surface conduction electron-emitting device. 13. The image forming apparatus according to claim 1, wherein the low secondary electron emission material is carbon.