JPH10269969A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent damage or deterioration caused by discharge generated along an atmospheric pressure supporting member. SOLUTION: This device has an electron source in which wiring arranged in one plane and a plurality of electron emission elements connected to the wiring are arranged within a vacuum container having a pair of the facing planes, an image forming member 12 arranged in the other plane, and an atmospheric pressure supporting member 5 arranged between a pair of the planes. The atmospheric pressure supporting member 5 is connected to a low resistant conductor 13 formed through an insulating layer 14 on the wiring and the image forming member 12, and the low resistant conductor 13 is connected to a current flow path 19 having low impedance on the outside through a connecting terminal 18 passing through a passing through hole of a vacuum container. The current flow path 19 is connected to the ground through a non-linear element 20, and the low resistant conductor 13 is connected to a synchronous power source device 22 which is synchronized with an electron source driving power source 21 so that the low resistant conductor 13 becomes the same potential as potential applied to the wiring arranged under the low resistant conductor 13 in normal driving.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus, and more particularly, to a highly reliable flat plate type image forming apparatus.

[0002]

2. Description of the Related Art CRTs have been widely used as image forming apparatuses for displaying images using electron beams.

On the other hand, in recent years, flat panel display devices using liquid crystal have been widely used in place of CRTs. However, since they are not self-luminous, they have problems such as having to have a backlight. Development of a light-emitting display device has been desired. As a self-luminous display device, a plasma display has recently begun to be commercialized.
At present, the principle of light emission is different from that of CRTs because of the contrast of images and good color development. If an electron source is formed by arranging a plurality of electron-emitting devices, and this is used in a flat plate type image forming apparatus, C
It is expected that light emission of the same quality as RT can be obtained, and much research and development has been performed. For example, JP-A-4-1638
No. 33 discloses a flat-plate electron beam image forming apparatus in which a linear hot cathode and a complicated electrode structure are enclosed in a vacuum vessel.

[0004] Since atmospheric pressure is applied to the inside and outside of the vacuum container, it is necessary to increase the thickness of the container wall or to provide an atmospheric pressure support member in the container in order to withstand the atmospheric pressure. In the case of a large-sized image forming apparatus, in order to support the atmospheric pressure by the thickness of the wall of the container, the thickness of the wall needs to be extremely large, and the weight of the apparatus increases. Therefore,
In order to realize a large flat plate type electron beam image forming apparatus,
It is required to provide an atmospheric pressure support member inside the vacuum vessel to support the atmospheric pressure.

In an image forming apparatus using an electron beam,
A high voltage is applied between the electron source and the image display member to accelerate electrons. The above-mentioned atmospheric pressure supporting member is installed mainly between the electron source and the image forming member, and the high voltage is applied to both ends thereof. When the atmospheric pressure supporting member has conductivity, a current flows due to the high voltage, thereby consuming power. From this point, it is desirable that the atmospheric pressure supporting member is insulative. However, the following problems may occur in the insulating atmospheric pressure support member. That is, the atmospheric pressure supporting member has a possibility that some of the electrons emitted from the electron source and irradiated on the image forming member are reflected and collide,
As a result, secondary electrons are emitted from the atmospheric pressure support member, which may be charged and the potential may rise. In this case, the electric field in the vicinity is distorted, the trajectory of the electron beam emitted from the electron source is bent, and the electron beam does not reach the original position of the image forming member, and the image quality such as color shift is degraded. A phenomenon occurs. Also, in some cases, discharge may occur along the side of the atmospheric pressure support structure,
When this current flows into the electron source, it damages the electron-emitting device,
Defects may occur in the image.

As a method of avoiding such charging and generation of discharge due to the charging, for example, a method of forming an atmospheric pressure supporting member from a high resistance conductive material through which a minute current flows is disclosed in Japanese Patent Publication No. 7-99679. There is.

Further, if there is a part where the contact between the atmospheric pressure supporting member and the image forming member is incomplete, the flow of the minute current becomes uneven, and the potential distribution is distorted and adversely affected. As disclosed in Japanese Patent Publication No. Hei 8-21346, a needle-like support and a metal cover connected to the support are provided on the upper part of the atmospheric pressure support member, and the potential of this part is all the same as that of the image forming member. It has also been reported how to do.

Japanese Patent Application Laid-Open No. 6-338269 discloses a method of preventing a discharge caused by a rise in the potential of a member outside a vacuum vessel in a CRT, by grounding the member via a surge absorber element. ing.

[0009]

In recent years, as portable information terminal equipment, for example, the same level as a liquid crystal display,
There is a demand for the development of an electron beam image forming apparatus having a smaller thickness.

The present applicant has already made many proposals regarding a surface conduction electron-emitting device and an image forming apparatus using the same. For example, it is described in JP-A-7-235255. Since this electron-emitting device has a simple structure and can be formed in large numbers over a large area,
Since the image display device can be formed without complicated components such as an electrode structure, it can be used for an extremely thin electron beam image forming device.

By the way, a voltage for accelerating electrons is applied between the electron source and the image forming member as described above. When a normal phosphor is used as the image forming member, light emission of a preferable color is performed. In order to obtain this voltage, it is preferable to make this voltage as high as possible, for example, about several kV.

In this case, the distance between the image display member and the electron source is narrower than in the prior art, and thus the image display member and the electron source face each other with a short distance between the side surfaces of the atmospheric pressure support member. Even if a conductive atmospheric pressure supporting member is used, there is a case where the danger of generating a discharge along the atmospheric pressure supporting member cannot be completely avoided.

A path through which a current flows when such a discharge occurs will be described with reference to an equivalent circuit shown in FIG. Reference numeral 31 denotes a point corresponding to the image forming member, to which a potential Va is applied.
Reference numeral 32a denotes the electric resistance of the atmospheric pressure support member, which normally has a predetermined high resistance value, but the resistance value decreases when a discharge occurs. Reference numeral 33 assumes that the atmospheric pressure support member is connected to one of the wirings of the electron source at the point where the member contacts the electron source. This point is connected to a circuit for applying a predetermined element drive voltage _Vf- via a wiring resistor 36, and a plurality of electron-emitting devices 37 are connected to this wiring. In FIG. 4, only one element is shown for the sake of simplicity. 38 and 3
Reference numeral 9 indicates points corresponding to the electrodes connected to the wirings of the electron-emitting devices, respectively. The electrodes at point 39 are connected to a circuit for applying a predetermined element driving voltage _{Vf +} via a resistor 40 having a wiring different from the above. ing. When a discharge occurs along the atmospheric pressure support member, the resistance 32a shown in FIG. 4 becomes smaller than usual, and a large current flows. This current flows from the point 33 in FIG. 4 to the wiring, a part of the current flows through the resistor 36, another part flows into another wiring via the electron-emitting device 37, and flows out of the image forming apparatus via the resistor 40. I do. At this time, if a certain amount or more of current flows through the electron-emitting device 37, the device is damaged or the amount of emitted electrons is reduced. Further, when the discharge current is large and the current flowing out of the image forming apparatus via the resistors 36 and 40 is large, an adverse effect such as damaging an electric circuit for applying a drive voltage to the element may be caused.

Therefore, in order to realize a highly reliable and thinner flat plate type electron beam image forming apparatus, even when a discharge occurs along the atmospheric pressure supporting member, the electron emitting element and the external drive circuit are required. There has been a demand for the development of a technique for preventing damage and deterioration.

[0015]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has the following configuration.

That is, an electron source formed by arranging a plurality of wirings and electron-emitting devices connected to the wirings on one of the planes in a vacuum vessel having a pair of planes facing each other; An image forming member disposed on the other plane to form an image by irradiating the electron beam emitted from the electron source; and a conductive atmospheric pressure supporting member disposed between the pair of planes. In the image forming apparatus having a voltage for accelerating electrons between the electron source and the electrode, the atmospheric pressure supporting member includes at least a part of a wire constituting the electron source. A low-resistance conductor formed above via an insulating layer and the image forming member, wherein the low-resistance conductor is connected to a low-impedance current outside the vacuum vessel through a connection terminal passing through a through hole of the vacuum vessel. Connected to the flow path, Current flow path of low impedance,
A voltage is applied in synchronization with an electron source drive power supply so that the low resistance conductor is connected to the ground via a non-linear element, and has the same potential as the potential applied to the wiring provided thereunder during normal driving. The image forming apparatus is connected to a synchronous power supply apparatus.

The non-linear element has a low impedance when a voltage higher than a predetermined threshold voltage is applied. For example, a surge absorber such as a discharge tube or a varistor, or a Zener diode can be used.

With this configuration, when a discharge occurs along the side surface of the atmospheric pressure support member, the discharge current flows into the low resistance conductor and then out of the vacuum vessel along the low impedance flow path. Then, it reaches the ground through the nonlinear element. The impedance Z of this channel
However, if the impedance is sufficiently lower than the impedance Z ′ between the low-resistance conductor and the ground due to the other flow paths, most of the discharge current flows to the ground through the flow path passing through the nonlinear element, and There is less risk of damage. It is natural that the smaller the ratio (Z / Z ') of the two values, the better. However, in order to clarify the effect, it is preferable that (Z / Z') ≤0.1.

Further, the low-resistance conductor is connected to a synchronous power supply for applying a voltage so as to have the same potential as that of the wiring below the vacuum vessel outside the vacuum vessel through a low-impedance current flow path. If this is not the case, the response characteristics when applying a voltage for driving the element through the wiring deteriorated due to the capacitance component between the wiring and the low-resistance conductor, and the capacitor was connected to the wiring provided with the low-resistance conductor. This is to prevent the response of only the element row (or column) from being delayed as compared with other rows (or columns).

The internal resistance of the synchronous power supply should be large enough so that when a discharge occurs at the atmospheric pressure support, the current flows to ground via the nonlinear element.

Needless to say, the provision of a non-linear element, whose impedance decreases and a current flows when a voltage equal to or higher than the threshold voltage is applied as described above, between the ground and the low-impedance flow path does not cause discharge, and This is because when the forming apparatus is operating normally, the low-resistance conductor and the wiring thereunder can have the same potential,
When a discharge occurs and the potential of the low-resistance conductor rises above a threshold value, the current is immediately led to the ground.
Therefore, the above threshold value is set slightly higher than the potential applied to the wiring in normal driving.

Further, when a discharge occurs along the atmospheric pressure supporting member, the potential of the low resistance conductor rises sharply, but does not exceed the potential Va (anode voltage) of the image forming member. Therefore, in order to prevent dielectric breakdown in the insulating layer between the wiring and the low-resistance conductor, Va / d ≦ Ep is satisfied when the dielectric breakdown electric field of the insulating layer is Ep and the thickness of the insulating layer is d. It is safe to set the insulating layer material and thickness as described above.

Here, d must be thicker as the breakdown electric field Ep is smaller, and if the insulating layer is too thick,
Since the shape of the electric field is significantly different from that of the portion without the low-resistance conductor, which affects the trajectory of the electrons emitted from the electron source, there is a disadvantage that only the electron beam near the atmospheric pressure support member is irradiated to the shifted position. May occur. Therefore, it is required to select an insulating layer material so that the dielectric breakdown electric field of the insulating layer can be increased and the thickness d can be reduced.
Specifically, glass or the like which is coated with a glass paste and heat-treated is preferably used, and a polymer resin such as a polyimide resin which is easy to form and process and has a large dielectric breakdown electric field is particularly preferable.

The connection between the low-resistance conductor and the low-impedance current flow path is made by a connection terminal penetrating through a through hole in the upper or lower surface of the vacuum vessel in order to avoid the following problems. That is, when the above-mentioned connection terminal is configured to pass through the joint between the lower surface and side members (rear plate and support frame) constituting the vacuum vessel and to be embedded in the frit glass used for the joint, electric discharge occurs, When a large current flows through the member, a part of the current leaks into the frit glass, whereby lead is precipitated in the frit glass. If this progresses, cracks may occur in the frit glass, and it may not be possible to maintain a vacuum. Therefore, a configuration that does not cause such a situation is required, and the configuration described above is adopted.

The present invention will be further described with reference to the drawings.

FIG. 1 is a plan view schematically showing an example of the configuration of the present invention, and shows the internal structure of the apparatus with a face plate removed. In FIG. 1, reference numeral 1 denotes a rear plate which also serves as a substrate for forming an electron source.
Various materials are used depending on the conditions, such as blue plate glass having a SiO ₂ film formed on the surface, glass having a low Na content, quartz glass, and ceramics. Note that a substrate for forming an electron source may be provided separately from the rear plate, and the two may be joined after forming the electron source. Reference numeral 2 denotes an electron source forming area in which a plurality of electron-emitting devices such as a field emission device and a surface conduction electron-emitting device are arranged, and wirings connected to the devices are formed so as to be driven according to the purpose. 3-1
Reference numeral 3-2 denotes a wiring for driving the electron source, which is taken out of the image forming apparatus and connected to a driving circuit (not shown) for the electron source. Reference numeral 4 denotes a support frame sandwiched between the rear plate 1 and a face plate (not shown), and is joined to the rear plate 1 by frit glass. Electron source drive wiring 3
-1 and 3-2 are buried in the frit glass at the joint between the support frame 4 and the rear plate 1 and are drawn out. Reference numeral 5 denotes an atmospheric pressure support member, which is made of ceramics, glass, an organic compound, or the like. The atmospheric pressure support member 5 is required to have appropriate conductivity. This conductivity can be obtained even if the material of the atmospheric pressure support member itself has conductivity or a material formed of an insulator. On the surface of the barometric pressure support member,
The conductive layer may or may not be coated.
The bottom surface of the atmospheric pressure support member is in contact with the low resistance conductor 13 formed on the corresponding line of the electron source driving wiring 3-1 via an insulating layer. An end of the low-resistance conductor 13 is a connection terminal contact portion 15. In the vacuum container, a getter 9, a getter shielding plate 10, and the like are additionally arranged as necessary.

FIG. 2 schematically shows the configuration of a cross section along the line AA in FIG. 11 is a face plate,
12 is an image forming member, and 14 is an insulating layer. The low-resistance conductor 13 is connected to a low-impedance wiring 19 outside the vacuum vessel via a connection terminal 18 (contacting the connection terminal contact portion 15) composed of a conductor rod 16 and an insulator 17. It is connected to ground via a non-linear element 20 such as a discharge tube. Further, as described above, it is also connected to the synchronous power supply device 22 for giving the same potential as the drive wiring 3-1 of the normal electron-emitting device. The wiring (3-1 and 3-2 not shown) is connected to the drive driver 21. The drive driver 21 and the synchronous power supply 22 are connected by a signal line 23 for achieving the above-mentioned synchronization.

FIG. 3 is a plan view schematically showing another example of the configuration of the present invention. In the case of this example, the atmospheric pressure support member 5
In this method, small members are arranged in a staggered manner, which has the effect of increasing the conductance during exhaust. FIG. 3 shows a case in which the wirings 3-1 and 3-3 in the row direction are extracted from both sides of the wiring for driving the electron source.

Also, the connection to the low impedance wiring
The structure which can be connected on both sides of the low resistance conductor wiring 13 is shown.

The situation where discharge occurs along the atmospheric pressure support member in the image forming apparatus of the present invention will be described with reference to the equivalent circuit diagram of FIG. The same components as those in the equivalent circuit diagram of FIG. 4 are denoted by the same reference numerals. 32a indicates the resistance of the atmospheric pressure supporting member 5. Point 41 corresponds to the low-resistance conductor 13 and 42 indicates the impedance of the low-impedance flow path 19. Reference numeral 20 denotes a non-linear element such as a discharge tube, a varistor, and a Zener diode. Since the main components of impedance are resistance and capacitance components,
FIG. 5 shows only the resistor and the capacitor.

When a discharge occurs on the side surface of the atmospheric pressure supporting member,
Point where the large current I corresponds to the low resistance conductor 13
41, most of which are low impedance
Path-flows out to ground through the nonlinear element (current
i₁). Resistance 32b of insulating layer, low resistance conductor sandwiching this
The current that has passed through the capacitor 32c between the
Through the line and the electron-emitting device, the current i_TwoAnd i_Threeage
Flowing. By making this current value small enough,
In order to eliminate the risk of damage to the
Large, the capacitance 32c is small, and the impedance is
Is, as described above, i ₁The impedance Z of the flow path is
Other flow paths (mainly i_Two, I_ThreeFlow path) impedance
If the current is sufficiently low compared to
Flows to the ground through the flow path through the nonlinear element,
The risk that the emitting element is damaged is reduced. Both
Naturally, the smaller the value ratio (Z / Z '), the better.
However, in order for the effect to become clear, (Z / Z ′) ≦ 0.
1, preferably (Z / Z ′) ≦ 0.01
More preferably,

The type of the electron-emitting device constituting the electron source used in the present invention is not particularly limited as long as the characteristics such as the electron emission characteristics and the size of the device are suitable for the target image forming apparatus. Absent. For example, a thermionic emission device, or a cold cathode device such as a field emission device, a semiconductor electron emission device, an MIM type electron emission device, and a surface conduction type electron emission device can be used.

The surface conduction electron-emitting device shown in the embodiments described below is preferably used in the present invention, and is the same as that described in Japanese Patent Application Laid-Open No. 7-235255 by the present applicant. There is a brief description below. FIG. 6 is a schematic diagram showing an example of the configuration of a single surface conduction electron-emitting device. FIG.
(B) is a sectional view.

In FIG. 6, reference numeral 51 denotes a substrate for forming an electron-emitting device; 52 and 53, a pair of device electrodes; 54, a conductive film connected to the device electrodes 52, 53; A part is formed. The electron-emitting portion is a high-resistance portion formed by partly destroying, deforming, and altering the conductive film by a forming process described later, and a crack is formed in a portion of the conductive film. Is to be released.

The forming step is performed by applying a voltage between the pair of element electrodes. The voltage to be applied is preferably a pulse voltage, and either the method of applying the pulse voltage having the same peak value shown in FIG. 7A or the method of applying the pulse voltage while gradually increasing the peak value shown in FIG. A method may be used.

After forming the electron-emitting portion by the forming process, a process called “activation” is performed. This is to repeatedly apply a pulse voltage to the element in an atmosphere in which an organic substance is present, thereby depositing a substance mainly composed of carbon or a carbon compound around the electron emitting portion. As a result, both the current flowing between the device electrodes (device current If) and the current accompanying the electron emission (emission current Ie) increase.

It is preferable that the electron-emitting device obtained through the above steps be subjected to a stabilization step. This step is a step of exhausting the organic substance in the vacuum container.
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 and an ion pump can be used.

The partial pressure of the organic substance in the vacuum vessel is a partial pressure at which the above-mentioned carbon and carbon compounds are not newly deposited.
× 10 ⁻⁶ Pa or less, more preferably 1.3 × 10 ⁻⁸ Pa
Pa or less is particularly preferred. Further, when evacuating the inside of the vacuum vessel, the entire vacuum vessel is heated, and the inner wall of the vacuum vessel,
It is preferable that the organic substance molecules adsorbed on the electron-emitting device be easily exhausted. The heating conditions at this time are 80 to 250
C., preferably 150 ° C. or higher, it is desirable to perform the treatment for as long as possible. Do. The pressure in the vacuum vessel needs to be as low as possible, and 1 × 10 ⁻⁵ Pa
Or less, more preferably 1.3 × 10 ⁻⁶ Pa or less.

It is preferable that the atmosphere at the time of driving after the stabilization step is performed is the same as that at the end of the stabilization treatment, but the present invention is not limited to this. Even if the degree of vacuum itself is slightly reduced, sufficiently stable characteristics can be maintained.

By employing such a vacuum atmosphere, the deposition of new carbon or carbon compound can be suppressed,
In addition, H ₂ O, O _{2 and the} like can be removed by being adsorbed on a vacuum vessel or a substrate, and as a result, the element current If and the emission current Ie are stabilized.

FIG. 8 schematically shows the relationship between the voltage Vf applied to the device and the device current If and the emission current Ie of the thus obtained surface conduction electron-emitting device. In FIG. 8, the emission current Ie is the device current If
, It is shown in arbitrary units. The vertical and horizontal axes are linear scales.

As shown in FIG. 8, when an element voltage higher than a certain voltage (called a threshold voltage, Vth in FIG. 8) is applied to the present element, the emission current Ie sharply increases, while the threshold voltage is increased. Below Vth, 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. If you use this,
It is possible to apply matrix wiring to the two-dimensionally arranged electron emitting elements, selectively emit electrons from desired elements by simple matrix driving, and irradiate the electrons to the image forming member to form an image.

An example of the structure of the fluorescent film as an image forming member will be described. FIGS. 9A and 9B are schematic diagrams illustrating a fluorescent film. The fluorescent film 56 can be composed of only a phosphor in the case of monochrome. In the case of a color fluorescent film, black stripes (FIG.
(A)) or a black conductive material 57 called a black matrix (FIG. 9B) and a phosphor 58. The purpose of providing the black stripes and the black matrix is to make the color separation between the phosphors 58 of the necessary three primary color phosphors black in the case of color display so that color mixing and the like become inconspicuous, An object of the present invention is to suppress a decrease in contrast due to light reflection. As a material of the black stripe, in addition to a material mainly containing graphite which is generally used, there is conductivity,
A material with low light transmission and reflection can be used.

As a method of applying the phosphor on the face plate 11, a precipitation method, a printing method or the like can be adopted regardless of monochrome or color. Usually, a metal back is provided on the inner surface side of the fluorescent film 56. The purpose of providing a metal back is
The face plate 1 emits light toward the inner surface side of the phosphor emission.
Improve brightness by specular reflection to one side, act as electrode for applying electron beam acceleration voltage, protect phosphor from damage due to collision of negative ions generated in 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 formed by depositing Al using vacuum evaporation or the like.

The face plate 11 further includes a fluorescent film 5
A transparent electrode may be provided on the outer surface side of the fluorescent film 56 in order to enhance the conductivity of the phosphor film 6.

In the case of color, it is necessary to make each color phosphor correspond to an electron-emitting device, and sufficient alignment is required.

According to the present invention having the above configuration,
It has become possible to improve the reliability of a thin flat plate type electron beam image forming apparatus.

[0048]

The present invention will be further described below with reference to examples. [Example 1] A plurality of surface conduction electron-emitting devices were formed on a rear plate also serving as a substrate, wired in a matrix to form an electron source, and an image forming apparatus was prepared using the electron source. The configuration of the device is the same as that shown in FIGS. Hereinafter, the creation procedure will be described with reference to FIGS. 10 (A) to 10 (G). (Step-a) 0.5 μm on the surface of the washed blue plate glass
The SiO ₂ layer is formed by sputtering, and the rear plate 1.

A device electrode 61 and a device electrode 62 of a surface conduction electron-emitting device are formed on the rear plate 1 by using a sputtering film forming method and a fetolithography method. Material is 5n
It is obtained by laminating m Ti and 100 nm Ni. The element electrode spacing was 2 μm (FIG. 10A). Element electrodes were formed along the X-direction wiring at a pitch of 290 μm for 720 elements. (Step-b) Subsequently, the Y-direction wiring 63 was formed by printing an Ag paste into a predetermined shape and firing it.
The wiring is extended to the outside of the electron source forming region, and becomes the electron source driving wiring 3-2 in FIG. The width of the wiring is 10
The thickness is 0 μm and the thickness is about 10 μm (FIG. 10B). (Step-c) Next, using a paste containing PbO as a main component and a glass binder, an insulating layer 64 is formed by the same printing method. This is to insulate the Y-directional wiring 63 from an X-directional wiring described later, and is formed to have a thickness of about 20 μm. A notch 65 is provided at the element electrode 62 to connect the X-directional wiring to the element electrode (FIG. 10C). (Step-d) Subsequently, the X-direction wiring 66 is connected to the insulating layer 6.
4 (FIG. 10D). The method is the same as that for the Y-direction wiring. The width of the wiring is 300 μm and the thickness is about 10 μm.
m. (Step-e) X-direction wiring 66 in contact with the atmospheric pressure support member
An interlayer insulating layer 67 is formed thereon. As in step c, Pb
Using a paste containing O as a main component and a glass binder, the interlayer insulating layer 67 was formed by repeating printing and firing 10 times to a thickness of about 200 μm by the same printing method. (Step-f) Subsequently, a low-resistance conductor layer 68 is formed on the interlayer insulating layer 67 (FIG. 10F). The method is the same as that for the Y-direction wiring, and the width is set to 100 μm and the thickness is set to 100 μm by printing five times. (Step-g) Further, a conductive film 69 made of PdO fine particles
To form A solution of the organic Pd compound is placed at a predetermined position,
Using a bubble jet type ink jet device, the liquid is applied as droplets and dried, and then dried at 300 ° C.
This was formed by performing a heat treatment for 10 minutes to form a PdO fine particle film (FIG. 10G). (Step-h) The same paste as used for forming the above-mentioned interlayer insulating layer 67 is printed and baked on the X-direction wiring at the position where the low-resistance conductor is to be formed, and the insulating layer 14 is provided.
The low resistance conductor 13 and the connection terminal contact portion 15 are formed by a printing method using a paste. (Step-i) The support frame 4 and the rear plate 1 are connected using frit glass. Getter 9 and getter shielding plate 10
Is simultaneously performed using frit glass. A dispersion of carbon fine particles is spray-coated on the inner surface of the container and dried to form an antistatic film. The forming conditions are such that the sheet resistance value of the antistatic film is about 10 ⁸ Ω / □. (Step-j) A ceramic atmospheric pressure support member is prepared. After forming a green sheet for forming a ceramic plate by a doctor blade method and forming the sheet into a desired shape, a carbon fine particle dispersion is spray-coated and dried by the same method as that used in Step-i. To form an antistatic film. (Step-k) Fix the atmospheric pressure support member at a predetermined position on the low resistance conductor. The fixing is performed using frit glass having some conductivity. (Step-l) Subsequently, a face plate is prepared. As in the case of the rear plate, a blue sheet glass provided with a SiO ₂ layer is used as a base. An opening for exhaust pipe connection, a connection terminal introduction port to a low resistance conductor, and a high voltage introduction terminal introduction port for connecting a high voltage Va to a high voltage power supply are formed in the image forming member by ultrasonic processing. Subsequently, a high-voltage introduction terminal connection portion is formed of Au by printing, a black stripe of a fluorescent film is formed, a stripe-shaped phosphor is formed, and a filming process is performed.
1 film was deposited by a vacuum evaporation method to form a metal back. Further, a carbon fine particle dispersion is sprayed on the surface of the face plate which is to be inside the container in the same manner as described above to form an antistatic film. Of the film thus formed, the portion formed on the metal back has an effect of reducing the reflection of the incident electron beam.

The support frame joined to the rear plate is joined to the face plate using frit glass. The connection terminal to the low-resistance conductor, the high-voltage introduction terminal, and the exhaust pipe are simultaneously joined. The connection terminal and the high-voltage introduction terminal are obtained by inserting a Cu rod coated with Au into an insulator mainly composed of alumina.

It should be noted that each electron-emitting device of the electron source is carefully aligned with the position of the fluorescent film on the face plate. (Step-m) The image forming apparatus is connected to a vacuum exhaust device via an exhaust pipe (not shown), and the inside of the container is exhausted. When the pressure in the container becomes 10 ⁻⁴ Pa or less, a forming process is performed.

The forming was performed by applying a pulse voltage having a gradually increasing peak value as schematically shown in FIG. 7B to the X-direction wiring for each row in the X-direction. The pulse interval T ₁ is 1
0 sec. , The pulse width T ₂ is 1 msec. And Although not shown in the figure, a rectangular wave pulse having a peak value of 0.1 V was inserted between the forming pulses, the current value was measured, and the resistance value of the electron-emitting device was simultaneously measured.
When the resistance value per element exceeds 1 MΩ, the forming process of that row is ended, and the process moves to the next row. By repeating this, the forming process is completed for all the rows. (Step-n) Next, an activation process is performed. Prior to this processing, the image forming apparatus is evacuated by an ion pump while maintaining the image forming apparatus at 200 ° C., and the pressure is reduced to 10 ⁻⁵ Pa or less. Subsequently, acetone is introduced into the vacuum vessel. The introduction amount was adjusted so that the pressure was 1.3 × 10 ⁻² Pa. Subsequently, a pulse voltage is applied to the X-direction wiring. The pulse waveform is a rectangular pulse having a peak value of 16 V, and the pulse width is 100 μsec. 125 μsec per pulse
Switch the X-direction wiring that applies pulses at intervals to the next row,
Applying a pulse to each wiring in the sequential direction is repeated.
As a result, 10 msec. Pulses will be applied at intervals. As a result of this processing, a deposited film containing carbon as a main component is formed near the electron emission of each electron-emitting device,
The element current If increases. (Step-o) Subsequently, the inside of the vacuum vessel is evacuated again. The evacuation was continued for 10 hours using an ion pump while maintaining the image forming apparatus at 200 ° C. This step is for removing organic substance molecules remaining in the vacuum vessel, preventing further deposition of the deposited film containing carbon as a main component, and stabilizing electron emission characteristics. (Step-p) After returning the image forming apparatus to room temperature, Step-n
A pulse voltage is applied to the X-direction wiring in the same manner as described above. Further, when a voltage of 4 kV is applied to the image forming member through the high voltage introducing terminal, the fluorescent film emits light. At this time, the ground connection terminal is connected to the ground. Visually, it is confirmed that there is no portion that does not emit light or a very dark portion, the application of voltage to the X-direction wiring and the image forming member is stopped, and the exhaust pipe is heated and sealed by sealing. Subsequently, getter processing is performed by high-frequency heating to complete the image forming apparatus.

In step e, the thickness of the insulating layer was determined from the above-mentioned dielectric strength and impedance.

The withstand voltage of the printed glass was 20 kV / mm, and the thickness of the insulating layer between the X-directional wiring and the low-resistance conductor was set to 200 μm in consideration of applying an electron accelerating voltage to the image forming member up to 4 kV. . Dielectric constant is about 6 × 10 ^-11 F /
m, and the area of the low resistance conductor formed in step f is 100
μm × 250 mm, the capacitance during this period is 30 pF
It is. The current pulse observed during discharge is nse
c. Since it may be of a short order, it is considered that the frequency component of the voltage applied between the low-resistance conductor and the wiring at the time of the occurrence of discharge needs to take into account up to about 1 GHz. The impedance due to capacitance for this component is about 22Ω. The resistance of the low-resistance conductor, the connection terminal, the low-impedance flow path, and the current flow path connected to the ground through the discharge tube was about 2Ω, assuming that the resistance of the discharge tube was practically negligible. I was satisfied. Comparative Example An image forming apparatus was prepared in the same manner as in Example 1, except that the low-resistance conductor was not provided, and there was no terminal, wiring, or the like connected thereto.

A voltage was applied to each of the image display devices of Example 1 and Comparative Example in the same manner as in the above-described Step-n.
The image forming member emits light.

As shown schematically in FIG. 11A, the measurement was carried out between a high-voltage power supply 71 and a high-voltage introduction terminal 72.
3 was placed, and the occurrence of discharge was detected by detecting the current value. 7
4 is a recorder and 75 is an image display device. The wiring 19 connected from the low-resistance conductor via the connection terminal 18 is connected to the ground via the discharge tube 20 and is also connected to the synchronous power supply 22 at the same time. The operating voltage of the discharge tube was 18V. The current flowing through the ammeter 73 is usually small,
This is thought to be mostly due to the current flowing through the inner surface of the vacuum vessel of the image forming apparatus 75 and the antistatic film of the atmospheric pressure support member, but as occasionally indicated by arrows as schematically shown in FIG. Peak appears. This indicates that a discharge has occurred in the vacuum vessel. By recording the current value in this manner, the number of times of occurrence of discharge can be known.

Observation of the above-mentioned image forming apparatus was continued for 10 hours. As a result, both of the image forming apparatuses of Example 1 and Comparative Example generated four discharges. In the device of the comparative example, a defect occurred at various parts of the screen, and the discharge current flowed into the wiring, and it was considered that the device was destroyed. However, in the device of the first embodiment, such a defect did not occur. Was. [Example 2] An electron source was formed according to the structure schematically shown in FIG. The atmospheric pressure support member was made in the same manner as in Example 1. The length (in the X direction) of one atmospheric pressure support member is 15
mm and the distance between the support members was also 15 mm.

The X-direction wiring is drawn to both sides of 3-1 and 3-3 to reduce the influence of wiring resistance. Similarly, the low resistance conductor 13 was taken out from both sides. For this reason, the resistance connected to the ground through the low impedance flow path and the discharge tube at the time of discharge was about 1Ω.

Except for these points, the other steps were the same as those in Example 1.

When the present embodiment was evaluated by the above-described method, almost the same effects as those of the first embodiment were obtained. Example 3 The same configuration as in Example 1 was adopted except that the insulating layer material formed between the low-resistance conductor and the wiring 3-1 was formed of polyimide. However, the thickness of the insulating layer is 100
μm.

The formation and printing were repeated five times by printing.

The dielectric strength of the polyimide resin is 100 kV /
In consideration of applying an electron acceleration voltage to the image forming member up to 10 kV, the thickness was set to 100 μm. The dielectric constant is about 3 × 10 ⁻¹¹ F / m, the impedance for a component having a frequency of about 1 GHz from the area of the low-resistance conductor of 100 μm × 250 mm is about 21 Ω, and the current flowing to the ground through the low-resistance conductor layer and the discharge tube. Since the resistance of the road was 2Ω, the above condition was satisfied.

The evaluation was performed in the same manner as described above.
As in Example 1, generation of defects due to discharge did not occur.

Further, the effect of the electron trajectory emitted from the electron source on the potential of the low-resistance conductor layer was reduced.

In the above embodiment, the case where the surface conduction electron-emitting device is used as the electron-emitting device constituting the electron source has been described. However, it goes without saying that the structure of the present invention is not limited to this. The same applies to the case where an electron source using a field emission type electron emitting device, a semiconductor electron emitting device or other various electron emitting devices is used.

In the embodiment, the rear plate of the image forming apparatus also serves as the substrate of the electron source. However, the rear plate is separated from the substrate, and after the electron source is formed, the substrate is fixed to the rear plate. Is also good.

In addition, within the scope of the technical idea of the present invention,
Various members shown in the embodiments may be appropriately changed.

[0068]

As described above, by adopting the structure of the present invention, even if a discharge is generated in the vacuum vessel of the image forming apparatus, it is possible to prevent the electron-emitting device from being deteriorated or destroyed. This makes it possible to realize a thin and flat type image forming apparatus with high reliability.

[Brief description of the drawings]

FIG. 1 is a plan view schematically illustrating an example of the configuration of an image forming apparatus according to the present invention.

FIG. 2 is a cross-sectional view schematically showing a configuration of a cross-section along AA in FIG.

FIG. 3 is a plan view schematically showing another example of the configuration of the image forming apparatus of the present invention.

FIG. 4 is an equivalent circuit diagram for explaining a state of discharge in a conventional image forming apparatus.

FIG. 5 is an equivalent circuit diagram for explaining a state of discharge in the image forming apparatus of the present invention.

FIGS. 6A and 6B are a plan view and a cross-sectional view schematically showing a configuration of a surface conduction electron-emitting device.

FIGS. 7A and 7B are diagrams showing waveforms of pulse voltages used for forming when manufacturing a surface conduction electron-emitting device. FIGS.

FIG. 8 is a diagram for explaining electrical characteristics of the surface conduction electron-emitting device.

FIGS. 9A and 9B are schematic diagrams illustrating the structure of a fluorescent film serving as an image display member.

FIGS. 10A to 10G are diagrams for explaining a part of the manufacturing process of the first embodiment.

11A is a block diagram of a device used in the evaluation of the present invention, and FIG. 11B is a diagram schematically showing a state in which the occurrence of discharge is detected by the device of FIG. 11A. It is.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rear plate 2 Electron source formation area 3-1 and 3-3 X direction wiring 3-2 Y direction wiring 4 Support frame 5 Atmospheric pressure support member 9 Getter 10 Getter shielding plate 11 Face plate 12 Image forming member 13 Low resistance conductor 14 Insulation layer 15 Connection terminal contact portion 16 Rod 17 Insulator 18 Connection terminal 19 Low impedance current flow path 20 Nonlinear element 21 Electron source drive circuit 22 Synchronous power supply 23 Signal line 31 Point corresponding to image forming member 32a Atmospheric pressure support member 32b Resistance of insulating layer 32c Capacitance of insulating layer 33 Contact part between atmospheric pressure support member and wiring 35 Contact part between insulating layer and wiring 36 Wiring resistance 37 Electron emitting element 38, 39 Element electrode 40 Wiring resistance 41 Low resistance conductor Corresponding point 42 Resistance of low impedance current flow path 51 Substrate 52, 53 Device electrode 54 Conductive film 5 Electron emission part 56 Fluorescent film 57 Black conductive material 58 Phosphor 61, 62 Device electrode 63 Y direction wiring 64 Interlayer insulating layer 65 Notch 66 X direction wiring 67 Insulating layer 68 Low resistance conductor 69 Conductive film 71 High voltage power supply 72 High voltage Introductory terminal 73 Ammeter 74 Recorder 75 Image forming device

Claims (6)

[Claims] 1. An electron source formed by arranging a plurality of wirings and electron-emitting devices connected to the wiring on one of the planes in a vacuum vessel having a pair of planes facing each other. An image forming member disposed on the other plane to form an image by irradiating the electron beam emitted from the electron source; and a conductive atmospheric pressure supporting member disposed between the pair of planes. An image forming apparatus comprising: a voltage for accelerating electrons between the electron source and the electrode, wherein the atmospheric pressure support member includes at least a part of a wire constituting the electron source. A low-resistance conductor formed above via an insulating layer and the image forming member, wherein the low-resistance conductor has a low-impedance current outside the vacuum vessel through a connection terminal that passes through a through hole of the vacuum vessel. Connected to the flow path, The current flow path of the impedance is connected to the ground via a non-linear element, and the low-resistance conductor has an electron source driving power source so as to have the same potential as the potential applied to the wiring provided thereunder in normal driving. An image forming apparatus connected to a synchronous power supply that applies a voltage in synchronization with the image forming apparatus. 2. A threshold voltage of the non-linear element is set to a voltage higher than a voltage applied by a normal drive to a wiring disposed under the low-resistance conductor via the insulating layer. The image forming apparatus according to claim 1, wherein: 3. An impedance Z between the low resistance conductor and ground via the low impedance current flow path when a voltage applied to the nonlinear element exceeds a threshold value;
The image forming apparatus according to claim 1, wherein an impedance Z ′ via a current flow path other than the low impedance current flow path satisfies Z / Z ′ ≦ 0.1. 4. 4. A voltage Va for accelerating the electrons, where d is the thickness of the insulating layer between the wiring and the low-resistance conductor, and Ep is the dielectric breakdown electric field of the material of the insulating layer.
2. The image forming apparatus according to claim 1, wherein the relationship with Va satisfies Va / d <Ep. 5. The image forming apparatus according to claim 1, wherein said insulating layer is formed of a polyimide resin. 6. The vacuum vessel according to claim 1, wherein a passage hole of the vacuum vessel is provided on an upper surface or a lower surface of the vacuum container.
The image forming apparatus according to any one of claims 1 to 5, wherein