JP3382460B2 - Electron emitting device, electron source, image forming apparatus using the same, and characteristic recovery method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron-emitting device, an electron source using the electron-emitting device, an image forming apparatus using the electron source, and a method for restoring their characteristics.

[0002]

2. Description of the Related Art Heretofore, two types of electron-emitting devices have been known, which are roughly classified into a thermoelectron-emitting device and a cold cathode electron-emitting device. The cold cathode electron emission device includes a field emission type (hereinafter referred to as “FE type”), a metal / insulating layer / metal type (hereinafter referred to as “MIM type”), a surface conduction type electron emission device, and the like.

As an example of the FE type, W. P. Dyke
and W. W. Dolan, "Field Emis
“Sion”, Advance in Electron
Physics, 8, 89 (1956) or C.I.
A. Spindt, “Physical Proper
ties of thin-filmfield em
ision cathodes withmollyb
denum cones ", J. Appl. Phy
s. , 47, 5248 (1976) and the like are known.

An example of the MIM type is C.I. A. Mea
d, "Operation of Tunnel-Emi
session devices ”, J. Appl. Phy
s. , 32,646 (1961) and the like are known.

As an example of the surface conduction electron-emitting device,
M. I. Elinson, Radio Eng. Elec
tron Phys. , 10, 1290 (1965) and the like.

The surface conduction electron-emitting device utilizes a phenomenon in which electron emission occurs when a current is passed through a thin film having a small area formed on an insulating substrate in parallel with the film surface. As this surface conduction electron-emitting device, one using the SnO ₂ thin film by Erinson et al., One using the Au thin film [G. Dittmer: "ThinSolid
Films ", 9,317 (1972)] , In 2 O 3
/ SnO ₂ thin film [M. Hartwell a
nd C.I. G. Fonstad: “IEEE Tran
s. ED Conf. , 519 (1975)], carbon thin films [Hiraki Araki et al .: Vacuum, Vol. 26, No. 1, p. 22 (1983)] and the like.

As a typical example of the structure of the surface conduction electron-emitting device, an example of the structure reported by the present applicant is schematically shown in FIG. 2A is a plan view and FIG. 2B.
Is a sectional view. In FIG. 2, 1 is a substrate, 2 and 3 are device electrodes, 4 is a conductive thin film, and 5 is an electron emitting portion. After forming the device electrodes 2 and 3 and the conductive thin film 4 on the substrate 1, the electron-emitting portion 5 is formed by an energization process called energization forming. By applying a voltage between the element electrodes 2 and 3 and causing a current to flow through the conductive thin film, the conductive thin film 4 is locally destroyed, deformed or altered to have an electrically high resistance state. To form the electron emission portion 5,
A crack is formed in a part of the conductive thin film, and when a voltage is applied between the device electrodes to flow a current, electrons are emitted from the vicinity of the crack.

The above-mentioned method for forming the device electrode and the conductive thin film,
Regarding the energization forming for forming the electron emitting portion and other steps, for example, an application by the applicant of the present application, JP-A-7-2
It is described in detail in Japanese Patent No. 35255.

Further, the above surface conduction electron-emitting device is
Since the structure is simple and the manufacturing is easy, there is an advantage that it is suitable for arraying a large number of elements over a large area. Therefore, by utilizing this characteristic, application to, for example, a charged beam source and a display device has been studied. As an example in which a large number of surface-conduction type electron-emitting devices are formed in an array, as will be described later, surface-conduction type electron-emitting devices are arranged in parallel, and both ends of each element are respectively connected (also called common wiring).
An electron source in which a large number of element rows connected to each other are arranged (for example, JP-A-64-31332, JP-A-1-283749, JP-A-2-257552).

In particular, as an image forming apparatus such as a display device, a flat panel display device using a liquid crystal has become popular in recent years instead of a CRT, but since it is not a self-luminous type, it must be equipped with a backlight. Therefore, the development of a self-luminous display device has been desired. As a self-luminous display device, an image forming device that is a display device in which an electron source in which a large number of surface conduction electron-emitting devices are arranged and a phosphor that emits visible light by electrons emitted from the electron source are combined is used. (Eg, US Pat. No. 5,066,
883).

[0011]

When the electron-emitting device is put to practical use, it is necessary that its electron-emitting property be stably maintained for a long time.

In the case of the surface conduction electron-emitting device, the important factors for the electron emission characteristics are the magnitude of the current associated with electron emission (hereinafter referred to as "emission current" (Ie)) and the electron emission efficiency (η).

Here, the electron emission efficiency means the ratio of the emission current Ie to the current flowing between the device electrodes (hereinafter referred to as "device current" If). That is, η = Ie / If
Is.

In practical use of the surface conduction electron-emitting device, it is required that the intensity of the emission current and the electron emission efficiency be stably maintained for a long period of time, and the characteristic itself has a large emission current. High electron emission efficiency is desirable.

For example, when the surface conduction electron-emitting device is applied to an image forming apparatus, the large emission current Ie is
It is necessary to obtain a bright image, and if the electron emission efficiency η is high, the power consumption for obtaining the same brightness can be small and the load on the drive circuit can be reduced, thus lowering the overall cost. Can be expected.

However, in the conventional surface conduction electron-emitting device, a satisfactory one has not been obtained in this respect, and the emission current Ie and the electron emission efficiency η are improved,
In some cases, further improvement in stability of electron emission characteristics may be required.

The object of the present invention is to solve the above-mentioned problems,
An object of the present invention is to provide a surface-conduction electron-emitting device having further excellent stability of electron emission characteristics, and further to provide a surface-conduction electron-emitting device having a good emission current Ie and electron emission efficiency η.

[0018]

The present invention made to solve the above-mentioned problems has the following constitution.

That is, the first aspect of the present invention is that a pair of element electrodes facing each other, a conductive thin film in electrical contact with both of the pair of element electrodes, and a part of the conductive thin film are formed on the substrate. In the electron-emitting device having the formed electron-emitting portion, the conductive thin film is formed of fine particles and is deposited on the surface of the conductive metal and the first metal element which is a main constituent element to form a low work function material portion. one not forming a and a two or more second metallic elements, the most stable Yi of the first metal element
The ion radius of ON is the most stable of the above-mentioned second metal elements.
It is characterized in that the second metal element moves from the inside of the conductive thin film to at least a part of the surface of the conductive thin film by energizing between the pair of device electrodes , which is larger than the ionic radius of the ions. It is in an electron-emitting device.

The above-mentioned first electron-emitting device of the present invention is further characterized in that "the conductive thin film is composed of fine particles made of an alloy containing the first metal element and the second metal element". it, "the conductive thin film, and the fine particles consisting essentially of the first metal element, essentially comprising microparticles consisting of the second metal element" is intended to include the this, the.

According to a second aspect of the present invention, one or a plurality of element rows in which a plurality of the electron-emitting devices according to the first aspect of the present invention are arranged in one direction are provided on a substrate, and the electron-emitting devices are driven. An electron source is characterized in that it has a wiring for performing the operation.

The above-mentioned second electron source of the present invention is further characterized in that "the above-mentioned wiring is a ladder-type wiring".
"The above wiring is wired in a matrix",
Is also included.

Further, a third aspect of the present invention is to form an image by irradiating a desired pixel with the electron source of the second aspect of the present invention and an electron beam emitted from the electron source in a vacuum container to emit light. An image forming apparatus is characterized by including an image forming member to be formed.

In a fourth aspect of the present invention, an image is formed by irradiating a desired pixel with the electron source of the second aspect of the present invention and an electron beam emitted from the electron source to emit light in a vacuum container. According to another aspect of the present invention, there is provided an image forming apparatus including an image forming member to be formed and an electron beam modulating unit that modulates an electron beam applied to the image forming member based on an input signal.

Further, a fifth aspect of the present invention is the above-mentioned first to third aspects of the present invention.
A fourth method for recovering the characteristics of an electron-emitting device, an electron source, or an image forming apparatus, wherein the electron-emitting device has a threshold voltage higher than a device current of the electron-emitting device, and A characteristic recovery method is characterized in that a voltage lower than the applied voltage is applied.

The term "fine particles" is frequently used in this specification, and its meaning will be described.

Small particles are called "fine particles", and particles smaller than this are called "ultrafine particles". It is widely known that particles smaller than "ultrafine particles" and having a number of atoms of about several hundreds or less are called "clusters".

However, each boundary is not strict, and changes depending on what kind of property is focused on for classification. In addition, "fine particles" and "ultrafine particles" may be collectively referred to as "fine particles", and the description in this specification is in accordance with this.

For example, "Experimental physics course 14 Surfaces and fine particles" (edited by Yoshio Kinoshita, published by Kyoritsu Shuppan on Sep. 1, 1986) states that "fine particles in this paper have a diameter of about 2-3 μm to 10 nm. Up to about 10 nm, especially when referred to as ultrafine particles, the particle size is from about 10 nm to 2 to 3 n
It means up to about m. It is not a strict matter because both are collectively referred to as fine particles, but it is a rough guideline. When the number of atoms constituting a particle is from 2 to several tens to several hundreds, it is called a cluster. ("Page 195, lines 22-26").

In addition, the definition of "ultrafine particles" in the "Hayashi / ultrafine particle project" of the New Technology Development Corporation has the following lower limit of the particle size.

In the "Ultrafine particle project" (1981-1986) of the Creative Science and Technology Promotion System, particles having a size (diameter) in the range of about 1 to 100 nm are called "ultrafine particles". Then, one ultrafine particle is about 100-
It is a collection of about 10 ⁸ atoms. On an atomic scale, ultrafine particles are large to huge particles. ("Ultrafine Particles-Creative Science and Technology" Hayashi Tax, Ryoji Ueda, Akira Tasaki
Edited by Mita Shuppan 1988, page 2, lines 1 to 4) /
"One that is smaller than ultrafine particles, that is, one particle composed of several to several hundred atoms is usually called a cluster" (ibid., Page 12, lines 13 to 13).

Based on the above general term,
In the present specification, "fine particles" are aggregates of a large number of atoms and molecules, the lower limit of the particle size is several Å to 1 nm, and the upper limit thereof is several μm.
I will refer to something of a degree.

[0033]

BEST MODE FOR CARRYING OUT THE INVENTION The electron-emitting device according to the present invention is classified into the cold cathode electron-emitting device as described above.
From the viewpoint of the electron emission mechanism, it can be called a surface conduction electron-emitting device.

Embodiments of the surface conduction electron-emitting device of the present invention will be described below. The overall configuration can be the configuration shown in FIG. 2, similar to the conventional surface conduction electron-emitting device. FIG. 1 is a schematic diagram for explaining the structure in the vicinity of the electron emitting portion in the case of the above-described first specific configuration. (Therefore, FIG. 1 is not an enlargement of the shape near the electron emitting portion of the electron emitting device of the present invention.) The low potential side and the high potential are sandwiched by the electron emitting portion formed by the energization forming process. The conductive thin films on the sides face each other. The conductive thin film is an aggregate of fine particles containing the above alloy as a main component. As a result of intensive studies, the present inventors presume that the state of electron emission from the electron emission portion shown here is as follows.

The electrons emitted from the electron emitting portion are affected by both the high-potential-side conductive thin film and the anode electrode (not shown) in the upper part of the drawing, part of which flies toward the anode and the other of which Is incident on the high potential side conductive thin film. A part of the incident electrons is elastically scattered, has the same kinetic energy as that at the time of incidence, and jumps out of the conductive thin film, and the other part is absorbed by the conductive thin film.

The electrons finally reaching the anode are observed as the emission current Ie, and the electrons absorbed by the conductive thin film on the high potential side are observed as a part of the device current If.

Assuming such a mechanism of electron emission, the influence of the work function of the surface of the conductive thin film on the electron emission characteristic is considered as follows.

The work function of the electron emitting portion affects the amount of electrons emitted from the electron emitting portion. The smaller the work function of this portion is, the more the amount of emitted electrons is increased, and the effect of increasing the emission current Ie is expected.

The work function of the high potential side conductive thin film surface affects the probability that incident electrons are elastically scattered. The lower the work function of this portion is, the higher the probability that electrons are elastically scattered becomes, and it is expected that the ratio of the emission current Ie to the device current If, that is, the electron emission efficiency η is increased.

Therefore, it can be said that the work function of the surface of the conductive thin film is preferably low. As a method for realizing this situation, it is considered that a material having a low work function is formed on the surface of the conductive thin film. However, on the surface of the conductive thin film, especially on the part related to the electron emission as described above, the temperature is locally increased due to the generation of Joule heat due to the current and the energy of the incident electrons, so that the low work function material is In the case of evaporation at a relatively low temperature, the part of the low work function material will be lost within a short time due to evaporation or the like, and it will be difficult to maintain stable electron emission characteristics.

Therefore, the element constituting the above-mentioned low work function material portion is contained in the conductive thin film, and this is continuously supplied to the lost portion of the above low work function material portion, whereby the electron It has been desired to realize a method for maintaining stable release characteristics.

The present inventor has obtained preliminary results that can be expected to diffuse and precipitate a low work function material on the surface of a fine particle film of an alloy satisfying appropriate conditions.
It was found that the desired effect can be obtained by applying this to the conductive thin film of the surface conduction electron-emitting device.

An appropriate condition is that the ionic radius of the ion with the most stable valence of the metal element of the main component of the alloy formed by the alloy fine particles and the metal element of the low work function material portion is compared. The condition is that it is smaller than the former.

A preliminary examination is carried out by heating the fine particle film in a vacuum and observing the composition change of the surface. When the above conditions are satisfied, a low work function material portion is formed on the fine particle film surface. It has been found that the proportion of elements that do increase with time. Although the reason why such a phenomenon occurs is not well understood, it is considered that the element constituting the low work function is deposited on the surface of the fine particles by heating and then diffuses through the fine particle surface inside the fine particle film to the fine particle film surface. It is estimated that there is. The phenomenon in which the elements constituting the low work function material portion are precipitated from the alloy may not be expected from the equilibrium diagram of the alloy, but in the fine particle film, the surface area is very large, and this portion is special. There is a situation,
I'm guessing it's playing some role.

In addition, regarding the ion radius, although the values of the ion radius for various ions have been reported by a plurality of researchers, the results may vary depending on the environment in which the ions are present, the method of determining the ion radius from the measured data, and the like. different. Therefore, the value itself is not absolute. However, since the magnitude relations of the various ions are almost the same, the conditions as described above can be set.

Based on the results of the above preliminary examination, a surface conduction electron-emitting device using the same alloy fine particle film as a conductive thin film was prepared. In this case, it is considered that the energy for precipitation and diffusion of the metal element forming the low work function material portion can be given by energizing the element instead of the heat treatment in the preliminary study. The formation of the first low work function material portion is performed by activation treatment in an atmosphere containing a vapor of a metal compound containing the same element as the metal element forming the low work function material portion, as described later. You may form by this.

The same effect can be obtained by using a mixed fine particle film of metal fine particles made of a metal element as a main component and metal fine particles made of a metal element constituting the low work function material portion instead of the alloy fine particle film. . In this case, it is natural that the above-mentioned precipitation process does not exist, and the former metal fine particles on the surface,
The metal elements constituting the low work function material portion from the latter fine particles are likely to diffuse to the fine particle film surface.

In consideration of the above conditions, Table 1 lists possible combinations of the metallic element as the main component and the metallic element constituting the low work function material portion.

[0049]

[Table 1]

The above is a description of the supposed operation of the specific embodiment of the surface conduction electron-emitting device of the present invention described above.

As shown in Table 1, each of the first
In many cases, the number of the second element that can be used is not limited to one, but there are two or more. Therefore, it is possible to use two kinds of elements simultaneously as the second element.

A method of manufacturing the surface conduction electron-emitting device of the present invention will be described with reference to FIG.

(1) The substrate 1 is thoroughly washed with a detergent, pure water, an organic solvent, etc., and an element electrode material is deposited by a vacuum vapor deposition method, a sputtering method, etc., and patterned by, for example, a photolithography technique to produce an element. The electrodes 2 and 3 are formed (FIG. 3A).

(2) In order to connect the device electrodes 2 and 3,
A conductive thin film 4 composed of an alloy fine particle film or a mixed fine particle film of at least two kinds of metal fine particles is formed (FIG. 3).
(B)).

As this method, for example, an alloy film is deposited on the substrate by a sputtering method using an alloy target. At this time, if the pressure of the sputtering gas is set to an appropriate pressure higher than that in the case of normal film formation, a normal continuous film is not formed, and a fine particle film accumulates. Also in the case of using the vapor deposition method, a fine particle film can be obtained by introducing an inert gas such as argon into the vapor deposition apparatus so as to have an appropriate pressure to deposit a thin film.

[0056] Further, when the thin film deposition by the sputtering or evaporation, using two or more targets or evaporation sources, by performing sputtering or vapor deposition alternately open and close the shutter, be a mixed fine particle film it can.

Besides the thin film deposition method as described above, it is also possible to obtain a desired fine particle film by applying an organic metal complex solution and heating and baking.

(3) Subsequently, a forming process is performed.
As an example of the method of this forming step, a method by energization will be described. When electricity is applied between the device electrodes 2 and 3 by using a power source (not shown), an electron emitting portion 5 having a changed structure is formed at the site of the conductive thin film 4 (FIG. 3C).
According to the energization forming, a site having a structural change such as breakage, deformation or alteration is locally formed in the conductive thin film 4. The portion constitutes the electron emitting portion 5. An example of the voltage waveform of energization forming is shown in FIG.

The voltage waveform is preferably a pulse waveform. For this, the method shown in FIG. 4 (a) in which a pulse having a constant pulse peak value is continuously applied and the method shown in FIG. 4 (b) in which a voltage pulse is applied while increasing the pulse peak value There is.

In FIG. 4A, T1 and T2 are the pulse width and pulse interval of the voltage waveform. Usually T1 is lμse
c. -10 msec. , T2 is 10 μsec. -10
msec. It is set in the range of. The peak value of the triangular wave (peak voltage during energization forming) is appropriately selected according to the form of the surface conduction electron-emitting device. Under such conditions, for example, a voltage is applied for several seconds to several tens of minutes. The pulse waveform is not limited to the triangular wave, and a desired waveform such as a rectangular wave can be adopted.

T1 and T2 in FIG.
It can be similar to that shown in (a). The peak value of the triangular wave (peak voltage during energization forming) can be gradually increased in steps of, for example, about 0.1V.

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

(4) In some cases, the element which has undergone forming is subjected to a treatment called an activation step. The activation process means that the device current If and the emission current Ie are
This is a process that changes significantly.

The activation step can be carried out, for example, by repeating the application of pulses in the same manner as the energization forming in an atmosphere containing a vapor of a metal compound containing a metal element that constitutes the low work function material. . Examples of the compound used for forming the atmosphere described above include metal halides such as fluoride, chloride, bromide, and iodide of the metal, alkyl compounds such as methylated compounds, ethylated compounds, and benzylated compounds,
Metal b-diketonates such as acetylacetonate, dipivanoylmethanate and hexafluoroacetylacetonate, metal enyl complexes such as allyl complex and cyclopentadienyl complex, arene complexes such as benzene complex, metal carbonyls, Examples thereof include metal alkoxides and the like, and compounds obtained by combining these.

As the metal compounds containing the elements listed in Table 1 as the metal elements constituting the low work function material portion, for example, NbF ₅ , NbC ₁₅ and Nb (C ₅ H ₅ )
(CO) ₄ Nb (C ₅ H ₅ ) ₂ Cl ₂ , Ta (C ₅ H
₅ ) (CO) ₄ , Ta (OC ₂ H ₅ ) ₅ , Ta (C ₅ H ₅
) ₂ Cl ₂ , Ta (C ₅ H ₅ ) ₂ H ₃ , WF ₆ , W
(CO) ₆ , W (C ₅ H ₅ ) ₂ Cl ₂ , W (C ₅ H ₅ )
₂ H ₂ , W (CH ₃ ) _{6 and the} like can be mentioned. In this case, a substance such as carbon may be contained in the coating film in addition to the metal depending on the conditions.

(5) It is preferable that the electron-emitting device obtained through these steps is subjected to a stabilizing step. This step is a step of removing molecules of the organic substance in the vacuum container and the metal compound introduced in the activation step. It is preferable to use a vacuum evacuation device that evacuates the vacuum container without using oil so that the oil generated from the device does not affect the characteristics of the element. Specifically, a vacuum evacuation device such as a sorption pump or an ion pump can be used.

The partial pressure of the organic component in the vacuum container is 1.3 × 10 6 which is the partial pressure at which carbon or carbon compound derived from the organic substance, or metal deposited in the activation step or the compound thereof is not newly deposited. ^-6 Pa or less is preferable, and further 1.3
Particularly preferably, it is not more than × 10 ^-8 Pa. Further, when the inside of the vacuum container is evacuated, it is preferable to heat the entire vacuum container so that the organic substance molecules or metal compound molecules adsorbed on the inner wall of the vacuum container or the electron-emitting device can be easily evacuated. The heating conditions at this time are 80 to 250 ° C., preferably 150 ° C. or higher, and it is desirable to perform the treatment for as long as possible, but it is not particularly limited to this condition, and the size and shape of the vacuum container,
It is carried out under conditions appropriately selected according to various conditions such as the structure of the electron-emitting device. The pressure in the vacuum vessel must be as low as possible, preferably 1 × 10 ⁻⁵ Pa or less, and 1.3
Particularly preferably, it is not more than × 10 ^-6 Pa.

It is preferable that the atmosphere at the time of driving after the stabilization step is maintained at the atmosphere at the end of the above-mentioned stabilization process, but the present invention is not limited to this, and the remaining organic substances and the activation step may be used. If the introduced metal compound is sufficiently removed, it is possible to maintain sufficiently stable characteristics even if the pressure itself is slightly increased.

By adopting such a vacuum atmosphere, the deposition of new metal or its compound or carbon or carbon compound can be suppressed, and the electron emission characteristics such as H ₂ O and O ₂ adsorbed on the vacuum container or the substrate can be suppressed. The gas that has a bad effect on can be removed, and as a result, the device current If and the emission current Ie are stabilized.

[0070]

[0071]

[0072]

[0073]

[0074]

[0075]

The basic characteristics of the electron-emitting device to which the present invention is applicable obtained through the above steps will be described with reference to FIGS. 6 and 7.

FIG. 6 is a schematic diagram showing an example of a vacuum processing apparatus, and this vacuum processing apparatus also has a function as a measurement / evaluation apparatus.

In FIG. 6, 11 is a vacuum container, and 1
2 is an exhaust pump. An electron emitting element is arranged in the vacuum container 11. 13 is a device voltage V applied to the electron-emitting device.
f is a power supply for applying f, 14 is an ammeter for measuring a device current If flowing through the conductive thin film 4 between the device electrodes 2 and 3, and 15 is an emission current Ie emitted from the electron emission portion 5 of the device. It is an anode electrode for capturing. Reference numeral 16 is a high voltage power supply for applying a voltage to the anode electrode 15, and 17 is an ammeter for measuring the emission current Ie emitted from the electron emission portion 5 of the device. As an example, the voltage of the anode electrode can be set in the range of 1 KV to 10 KV, and the distance H between the anode electrode and the electron-emitting device can be set in the range of 2 mm to 8 mm.

The vacuum container 11 is provided with equipment (not shown) necessary for measurement in a vacuum atmosphere such as a vacuum gauge (not shown) so that measurement and evaluation can be performed in a desired vacuum atmosphere. Has become. The exhaust pump 12 is composed of a normal high vacuum device system including a turbo pump and a rotary pump, and an ultra high vacuum device system including an ion pump. The entire vacuum processing apparatus provided with the electron source substrate shown here can be heated by a heater (not shown). Therefore, by using this vacuum processing apparatus, the steps after the above-described energization forming can be performed.

FIG. 7 shows the emission current Ie, the device current If, and the device voltage V measured by using the vacuum processing apparatus shown in FIG.
It is the figure which showed the relationship of f typically. In FIG. 7,
Since the emission current Ie is extremely smaller than the device current If, it is shown in arbitrary units. Incidentally. Both the vertical and horizontal axes are linear scales.

As is apparent from FIG. 7, the surface conduction electron-emitting device of the present invention has three characteristic properties with respect to the emission current Ie. (I) In this device, the emission current Ie rapidly increases when a device voltage higher than a certain voltage (called a threshold voltage, Vth in FIG. 7) is applied. On the other hand, when the device voltage is lower than the threshold voltage Vth, the emission current Ie increases. Almost no Ie is detected. That is, the emission current Ie
Is a non-linear element having a clear threshold voltage Vth with respect to. (Ii) Since the emission current Ie is monotonically increasing dependent on the element voltage Vf, the emission current Ie can be controlled by the element voltage Vf. (Iii) The emission charge captured by the anode electrode 15 is
It depends on the time for which the device voltage Vf is applied. That is, the amount of charges captured by the anode electrode 15 can be controlled by the time for which the device voltage Vf is applied.

As can be understood from the above description, the surface conduction electron-emitting device of the present invention can easily control the electron emission characteristics according to the input signal. If this property is utilized, an electron source composed by arranging a plurality of electron-emitting devices,
It can be applied to various fields such as an image forming apparatus.

In the surface conduction electron-emitting device of the present invention, it is possible to recover the once deteriorated electron emission characteristics by the following method.

That is, usually, a voltage lower than the voltage applied when the device is driven to emit electrons is applied to the device. By this operation, the characteristics can be recovered even when the characteristics are slightly deteriorated when the element is continuously driven for a long time.

The reason why there is such an effect is considered as follows. In the device of the present invention, even if the low work function material portion on the surface of the conductive thin film is gradually lost due to driving, necessary elements are gradually replenished from the inside of the conductive thin film, so that the function is maintained. be able to. However, in a place where the conditions are severe and the low work function material portion is heavily consumed, for example, at the end of the high-potential-side conductive thin film of the electron-emitting portion, the supply of the above-mentioned elements cannot be completed in time, so that some deterioration occurs. It seems to indicate. At this time, if a voltage lower than that during normal driving is applied, the consumption of the low work function material portion is reduced, and it is considered that the characteristics are restored when the supply of the above elements from the inside proceeds to some extent.
However, the voltage applied at this time needs to be higher than the threshold voltage of the If-Vf characteristic. This is considered to be because when the applied voltage is lower than the threshold voltage, no current flows through the element, and energy for diffusing / moving the element is not applied.

Although FIG. 7 shows an example in which the element current If monotonously increases with respect to the element voltage Vf (hereinafter referred to as “MI characteristic”), the element current If is a voltage control type with respect to the element voltage Vf. Negative resistance characteristics (hereinafter referred to as "VCNR characteristics"
Say. ) May be shown (not shown). These characteristics can be controlled by controlling the above process.

Next, an electron source constructed by arranging a plurality of the above surface conduction electron-emitting devices on a substrate and an image forming apparatus constructed by using the electron source will be described.

Various arrangements of electron-emitting devices can be adopted.

As an example, a large number of electron-emitting devices arranged in parallel are individually connected at both ends, a large number of rows of electron-emitting devices are arranged (referred to as a row direction), and a direction (column direction) orthogonal to this wiring is formed. There is a ladder-shaped arrangement in which the control electrode (also referred to as a grid) arranged above the electron-emitting device controls and drives the electrons from the electron-emitting device. Separately, a plurality of electron-emitting devices are arranged in a matrix in the X and Y directions, and one of electrodes of the plurality of electron-emitting devices arranged in the same row is commonly connected to a wiring in the X direction. For example, the other of the electrodes of the plurality of electron-emitting devices arranged in the same column is commonly connected to the wiring in the Y direction. This is a so-called simple matrix arrangement. First, the simple matrix arrangement will be described in detail below.

The surface conduction electron-emitting device to which the present invention can be applied has the characteristics (i) to (iii) as described above. That is, the emitted electrons from the surface conduction electron-emitting device can be controlled by the peak value and width of the pulse voltage applied between the opposing device electrodes at the threshold voltage or higher. On the other hand, below the threshold voltage, it is hardly emitted. According to this characteristic, even when a large number of electron-emitting devices are arranged, if a pulsed voltage is appropriately applied to each device, the surface conduction electron-emitting device is selected according to the input signal and the electron emission device is selected. The amount of release can be controlled.

Based on this principle, an electron source substrate obtained by arranging a plurality of electron-emitting devices to which the present invention can be applied will be described below with reference to FIG. In FIG. 8, 21 is an electron source substrate, 22 is an X-direction wiring, and 23 is a Y-direction wiring.
Reference numeral 24 is a surface conduction electron-emitting device, and 25 is a wire connection.

The m X-direction wirings 22 are Dx1 and Dx.
2, ... Dxm, and can be made of a conductive metal or the like formed by a vacuum deposition method, a printing method, a sputtering method, or the like. The wiring material, film thickness, and width are appropriately designed. Y
The directional wiring 23 is composed of n wirings Dy1, Dy2, ..., Dyn, and is formed similarly to the X-directional wiring 22. An interlayer insulating layer (not shown) is provided between the m number of X-direction wirings 22 and the n number of Y-direction wirings 23 to electrically separate the two (m and n are both Positive integer).

The interlayer insulating layer (not shown) is made of SiO ₂ or the like formed by a vacuum vapor deposition method, a printing method, a sputtering method or the like. For example, it is formed in a desired shape on the entire surface or a part of the substrate 21 on which the X-direction wiring 22 is formed, and in particular, in order to withstand the potential difference at the intersection of the X-direction wiring 22 and the Y-direction wiring 23, the film thickness, The material and manufacturing method are appropriately set. The X-direction wiring 22 and the Y-direction wiring 23 are drawn out as external terminals.

A pair of electrodes (not shown) forming the surface conduction electron-emitting device 24 are electrically connected by m X-direction wirings 22, n Y-direction wirings 23 and a connection 25 made of a conductive metal or the like. Has been done.

The material forming the wirings 22 and 23, the material forming the connection 25, and the material forming the pair of element electrodes may be the same or different in some or all of the constituent elements. Good. These materials are appropriately selected, for example, from the above-mentioned material of the device electrode. When the material forming the element electrode and the wiring material are the same, the wiring connected to the element electrode can also be referred to as an element electrode.

A scanning signal applying means (not shown) for applying a scanning signal for selecting a row of the surface conduction electron-emitting devices 24 arranged in the X direction is connected to the X-direction wiring 22. On the other hand, the Y-direction wiring 23 is connected to a modulation signal generating means (not shown) for modulating each row of the surface conduction electron-emitting devices 24 arranged in the Y-direction according to a human power signal. The driving voltage applied to each electron-emitting device is supplied as a difference voltage between the scanning signal and the modulation signal applied to the device.

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

An image forming apparatus constructed by using an electron source having such a simple matrix arrangement will be described with reference to FIGS. 9, 10 and 11. 9 is a schematic view showing an example of the image display device of the image forming apparatus, and FIG.
FIG. 3 is a schematic view of a fluorescent film used in the image forming apparatus of FIG. FIG. 11 is a block diagram showing an example of a drive circuit for displaying according to an NTSC television signal.

In FIG. 9, 21 is an electron source substrate on which a plurality of electron-emitting devices are arranged, 31 is a rear plate to which the electron source substrate 21 is fixed, and 36 is a fluorescent film 34 on the inner surface of a glass substrate 33.
And a metal back 35 and the like. Reference numeral 32 denotes a support frame, and the rear plate 31 and the face plate 36 are joined to the support frame 32 by using frit glass having a low melting point.

Reference numeral 24 corresponds to the electron emitting portion in FIG. Reference numerals 22 and 23 denote an X-direction wiring and a Y-direction wiring connected to the pair of device electrodes of the surface conduction electron-emitting device.

The envelope 37 is composed of the face plate 36, the support frame 32, and the rear plate 31, as described above. Since the rear plate 31 is provided mainly for the purpose of reinforcing the strength of the substrate 21, if the substrate 21 itself has sufficient strength, the separate rear plate 31 can be omitted. That is, the support frame 32 is directly attached to the substrate 21, and the face plate 36, the support frame 32, and the substrate 21 are used to seal the enclosure 3.
7 may be configured. On the other hand, by installing a support body (not shown) called a spacer between the face plate 36 and the rear plate 31, it is possible to configure the envelope 37 having sufficient strength against atmospheric pressure.

FIG. 10 is a schematic diagram showing a fluorescent film. In the case of monochrome, the fluorescent film 34 can be composed of only a fluorescent material. In the case of a color phosphor film, it can be composed of a black conductive material 38 called a black stripe or a black matrix depending on the arrangement of the phosphors and a phosphor 39. In the case of color display, the purpose of providing the black stripes and the black matrix is to make the mixed portions between the respective phosphors 39 of the three primary color phosphors black so as to make the color mixture inconspicuous, and the phosphor film 34.
It is to suppress the decrease in contrast due to the reflection of external light. As the material of the black stripe, in addition to a commonly used material containing graphite as a main component, a material having conductivity and having little light transmission and reflection can be used.

As a method for applying the phosphor to the glass substrate 33, a precipitation method, a printing method or the like can be adopted regardless of monochrome or color. A metal back 35 is usually provided on the inner surface side of the fluorescent film 34. The purpose of providing a metal back is
Of the light emitted from the phosphor, the light emitted to the inner surface side is applied to the face plate 3
Improve the brightness by mirror-reflecting to the 6 side, act as an electrode for applying an electron beam accelerating voltage, protect the phosphor from damage due to collision of negative ions generated in the envelope, etc. Is. In the metal back, after the phosphor film is produced, the inner surface of the phosphor film is smoothed (usually called “filming”),
After that, Al can be produced by depositing Al using vacuum deposition or the like.

The face plate 36 is further provided with the fluorescent film 3
In order to enhance the conductivity of No. 4, a transparent electrode (not shown) may be provided on the outer surface side of the fluorescent film 34.

When performing the above-mentioned sealing, in the case of color, it is necessary to associate each color phosphor with the electron-emitting device.
Sufficient alignment is essential.

An example of a method of manufacturing the image forming apparatus shown in FIG. 9 will be described below.

FIG. 12 is a schematic diagram showing the outline of the apparatus used in this step. The image forming apparatus 41 is connected to the vacuum chamber 43 via an exhaust pipe 42, and is further connected to an exhaust apparatus 45 via a gate valve 44. In the vacuum chamber 43, a pressure gauge 46, a quadrupole mass analyzer 47, etc. are attached in order to measure the internal pressure and the partial pressure of each component in the atmosphere. Since it is difficult to directly measure the pressure inside the envelope 37 of the image display device 41, the pressure inside the vacuum chamber 43 is measured to control the processing conditions.

A gas introduction line 48 is connected to the vacuum chamber 43 in order to introduce a necessary gas into the vacuum chamber to control the atmosphere. An introduction substance source 50 is connected to the other end of the gas introduction line 48, and the introduction substance is stored in an ampoule, a cylinder or the like. In the middle of the gas introduction line, an introduction control means 49 for controlling the rate of introducing the introduction substance is provided. As the introduction amount control means, specifically, a valve capable of controlling a flow rate to escape such as a slow leak valve, a mass flow controller, or the like can be used depending on the type of introduction substance.

The inside of the envelope 37 is evacuated by the apparatus shown in FIG. 12 to perform forming. At this time, for example, as shown in FIG. 13, the Y-direction wiring 23 is connected to the common electrode 51, and X
The power supply 5 is supplied to all of the elements 24 connected to one X-direction wiring selected by the row selection means 53 in the directional wiring 22.
2, it is possible to apply voltage pulses at the same time to perform forming. The conditions such as the shape of the pulse and the determination of the end of processing may be selected according to the method described above regarding the forming of the individual element. Further, by sequentially switching the rows selected by the row selecting means 53 to the plurality of X-direction wirings, the pulses connected with the plurality of X-direction wirings are collectively applied by sequentially applying (scrolling) the pulses whose phases are shifted. It is also possible to form.

After the forming is completed, an activation process is performed.
After sufficiently exhausting the inside of the envelope 37, the metal compound is introduced from the gas guide line 48.

By applying a voltage to each electron-emitting device in the atmosphere thus formed containing a metal compound,
Similar to the case of the individual element, the metal is deposited in the vicinity of the electron emitting portion and the amount of electron emission increases. The voltage application method at this time is to connect the element connected to one selected X-direction wiring by the same connection as in the case of forming,
A voltage pulse may be applied. Moreover, you may perform activation collectively by scrolling.

After the activation step, it is preferable to carry out the stabilization step as in the case of the individual element.

An exhaust pipe 42 by an exhaust device 45 that does not use oil such as an ion pump and a sorption pump while heating the envelope 37 and maintaining it at 80 to 250 ° C.
After exhausting through an atmosphere to create an atmosphere in which the organic substance and the metal compound introduced during the activation treatment are sufficiently small, the exhaust pipe is heated by a burner to be melted and sealed. A getter process can be performed to maintain the pressure after the envelope 37 is sealed. This is because the getter placed at a predetermined position (not shown) in the envelope 37 is heated by resistance heating or high-frequency heating immediately before or after the envelope 37 is sealed. Then, it is a process of forming a vapor deposition film. The getter usually has Ba or the like as a main component, and maintains the atmosphere in the envelope 37 by the adsorption action of the vapor deposition film.

Next, a configuration example of a drive circuit for performing television display based on a television signal of the NTSC system on an image display device constructed by using an electron source having a simple matrix arrangement will be described with reference to FIG. To do. In FIG. 11, 61 is an image display device, 62 is a scanning circuit, 63 is a control circuit, and 64 is a shift register. 65 is a line memory, 66 is a sync signal separation circuit, 67 is a modulation signal generator,
Vx and Va are DC voltage sources.

The image display device 61 includes terminals Dox1 to Dox1.
oxm, terminals Doy1 to Doyn, and high-voltage terminal Hv
It is connected to an external electric circuit via. Terminal Dox1
To Doxm, an electron source provided in the image display device, that is, a group of surface conduction electron-emitting devices that are matrix-wired in a matrix of M rows and N columns is sequentially driven row by row (N elements). A scanning signal is applied.

A modulation signal for controlling the output electron beam of each element of the surface conduction electron-emitting devices of one row selected by the scanning signal is applied to the terminals Doy1 to Doyn. The high-voltage terminal Hv is supplied with a direct-current voltage of, for example, 10 KV from the direct-current voltage source Va, which imparts sufficient energy to excite the phosphor to the electron beam emitted from the surface conduction electron-emitting device. This is the acceleration voltage for

The scanning circuit 62 will be described. The circuit is provided with M switching elements inside (schematically shown by S1 to Sm in the figure). Each switching element selects either the output voltage of the DC voltage source Vx or OV (ground level) and is electrically connected to the terminals Dox1 to Doxm of the surface image display device 61. Each of the switching elements S1 to Sm operates based on the control signal Tscan output from the control circuit 63, and can be configured by combining switching elements such as FETs.

In the case of the present example, the DC voltage source Vx is a driving voltage applied to an unscanned element based on the characteristics (electron emission threshold voltage) of the surface conduction electron-emitting device, and the electron emission threshold value is applied. It is set to output a constant voltage that is less than or equal to the voltage.

The control circuit 63 has a function of matching the operation of each part so that an appropriate display is performed based on an image signal input from the outside. The control circuit 63, based on the synchronization signal Tsync sent from the synchronization signal separation circuit 66, outputs Tscan, Tsft, and Tm to each unit.
Each ry control signal is generated.

The sync signal separation circuit 66 is a circuit for separating the sync signal component and the luminance signal component from the NTSC system television signal input from the outside, and uses a general frequency separation (filter) circuit or the like. Can be configured. The sync signal separated by the sync signal separation circuit 66 is composed of a vertical sync signal and a horizontal sync signal.
It is shown as a sync signal. The luminance signal component of the image separated from the television signal is represented as a DATA signal for convenience. The DATA signal is input to the shift register 64.

The shift register 64 is for converting the DATA signals serially input in time series into serial / parallel conversion for each line of the image, and based on the control signal Tsft sent from the control circuit 63. (I.e., the control signal Tsft is applied to the shift register 64
It can be said that it is the shift clock. ). The serial / parallel converted image data for one line (corresponding to driving data for n electron-emitting devices) is converted into N parallel signals Id1 to Idn as the shift register 6
It is output from 4. The line memory 65 is a storage device for storing data for one line of an image only for a required time, and appropriately stores the contents of Id1 to Idm according to the control signal Tmry sent from the control circuit 63. The stored contents are output as Id'1 to Id'n and input to the modulation signal generator 67.

The modulation signal generator 67 outputs the image data Id '.
1 to Id'n is a signal source for appropriately driving and modulating each of the surface conduction electron-emitting devices, and the output signal is a surface conduction type inside the image display device 61 through terminals Doyl to Doyn. It is applied to the electron-emitting device.

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, the electron emission has a clear threshold voltage Vth, and the 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. Therefore, when a pulsed voltage is applied to this element, for example, electron emission does not occur even if a voltage below the electron emission threshold is applied, but when a voltage above the electron emission threshold is applied, an electron beam is emitted. Is output. At that time, the intensity of the output electron beam can be controlled by changing the peak value Vm of the pulse. Further, it is possible to control the total amount of charges of the electron beam output 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. When carrying out the voltage modulation method, as the modulation signal generator 67, a circuit of the voltage modulation method is used which generates a voltage pulse of a fixed length and appropriately modulates the peak value of the pulse according to the human-powered data. be able to.

In carrying out the pulse width modulation method,
As the modulation signal generator 67, it is possible to use a circuit of a pulse width modulation system that generates a voltage pulse having a constant peak value and appropriately modulates the width of the voltage pulse according to input data.

The shift register 64 and the line memory 65
Can adopt both a digital signal type and an analog signal type. 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 sync signal separation circuit 66 into a digital signal, which may be provided with an A / D converter at the output portion of 66. In connection with this, the circuit used for the modulation signal generator 67 is slightly different depending on whether the output signal of the line memory 65 is a digital signal or an analog signal. That is, in the case of the voltage modulation method using a digital signal,
For the modulation signal generator 67, for example, a D / A conversion circuit is used, and an amplification circuit or the like is added if necessary. In the case of the pulse width modulation method, the modulation signal generator 67 includes, for example, a high-speed oscillator and a counter for counting the number of waves output from the oscillator, and a comparator for comparing the output value of the counter with the output value of the memory. A circuit that combines (comparators) is used. If necessary, an amplifier for voltage-amplifying the pulse-width-modulated modulation 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, the modulation signal generator 67 may be an amplifier circuit using, for example, an operational amplifier, and a level shift circuit or the like may be added if necessary. In the case of the pulse width modulation method, for example, a voltage control type oscillation circuit (VOC) can be adopted, and an amplifier for amplifying the voltage up to the drive voltage of the surface conduction type electron-emitting device can be added if necessary.

In the image display device of the present invention having such a configuration, each electron-emitting device has a terminal Do outside the container.
Electrons are emitted by applying a voltage via x1 to Doxm and Doy1 to Doyn. High voltage terminal H
A high voltage is applied to the metal back 35 or the transparent electrode (not shown) via v to accelerate the electron beam. The accelerated electrons collide with the fluorescent film 34 to generate light emission and form both images.

This configuration 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 is mentioned, but the input signal is not limited to this, and P
In addition to the AL and SECAM systems, a TV signal system (for example, a high-definition TV such as the MUSE system) including a large number of scanning lines can be adopted.

Next, a ladder type electron source and an image forming apparatus will be described with reference to FIGS. 14 and 15.

FIG. 14 is a schematic diagram showing an example of a ladder-type electron source. In FIG. 14, 21 is an electron source substrate and 24 is an electron-emitting device. 26, Dx1 to Dx1
Reference numeral 0 is a common wire for connecting the electron-emitting device 24. A plurality of electron-emitting devices 24 are arranged in parallel in the X direction on the substrate 21 (this is called a device row). A plurality of such element rows are arranged to form an electron source. By applying a drive voltage between the common lines 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 the element row from which the electron beam is desired to be emitted.
A voltage equal to or lower than the electron emission threshold value is applied to the element row that does not emit the electron beam. Common wiring Dx2 to Dx between each element row
9 is, for example, Dx2 and Dx3, Dx4 and Dx5, Dx6
, And Dx7, and Dx8 and Dx9 can also have the same wiring.

FIG. 15 is a schematic view showing an example of a panel structure in an image forming apparatus provided with a ladder-type electron source. 71 is a grid electrode, 72 is a hole for passing electrons, and 73 is a terminal outside the container made of Dox1, Dox2, ..., Doxm. 74 is an external terminal of the container made of G1, G2, ..., Gn connected to the grid electrode 71. In FIG. 15, the same parts as those shown in FIGS. 9 and 14 are designated by the same reference numerals as those shown in these figures. A major difference between the image forming apparatus shown here and the image forming apparatus having the simple matrix arrangement shown in FIG. 9 is whether or not the grid electrode 71 is provided between the electron source substrate 21 and the face plate 36.

In FIG. 15, a grid electrode 71 is provided between the substrate 21 and the face plate 36. The grid electrode 71 is for modulating the electron beam emitted from the surface conduction electron-emitting device, and is for passing the electron beam through the stripe-shaped electrodes provided orthogonal to the device rows in the ladder type arrangement. , One circular opening 72 is provided for each element. The shape and installation position of the grid are not limited to those shown in FIG. For example, it is possible to provide a large number of passage openings in a mesh shape as openings, and it is also possible to provide a grid around or near the surface conduction electron-emitting device.

The external terminal 73 and the grid external terminal 74 are electrically connected to a control circuit (not shown).

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

The image forming apparatus of the present invention is used as a display apparatus for television broadcasting, a display apparatus such as a video conference system, a computer, and the like, as an image forming apparatus as an optical printer constituted by using a photosensitive drum and the like. Can also be used.

[0138]

EXAMPLES The present invention will be described below based on examples. Incidentally, the embodiment of the present invention is not limited to the following examples, within the scope of not changing the gist of the present invention,
Each element may be replaced or the design may be changed.

[Embodiment 1] This embodiment is a surface conduction electron-emitting device which belongs to one mode of the present invention as shown in FIG. The conductive thin film constituting the present example is composed of fine particles of an alloy containing Pd as the main metal element and Zr as the metal element constituting the low work function material portion.

The electron-emitting device of this example has the structure shown in FIG. The manufacturing method of this embodiment will be described below with reference to FIG.

Step-a Quartz glass is used as the substrate 1. This is washed with a detergent, pure water and an organic solvent, and the photoresist (RD-2
00ON: Hitachi Chemical Co., Ltd.) applied with a spinner,
Re-prebaking was performed by heating at ℃ for 20 minutes. Continuing,
After exposing using an exposure mask corresponding to an electrode interval L = 2 μm and an electrode length W = 300 μm and developing with a developing solution to form an opening corresponding to the electrode shape, prebaking treatment at 120 ° C. for 20 minutes was performed. Then, a resist pattern was formed.

Step-b: Then, a film having a thickness of 100 nm is formed on the substrate by a vacuum evaporation method.
Ni was deposited, the resist pattern was dissolved with an organic solvent, and the device electrodes 2 and 3 were formed by lift-off (FIG. 3).
(A)).

Step-c Cr having a thickness of 50 nm was deposited by a vacuum deposition method. Photoresist (AZ1370: Hoechst)
Was applied and a resist mask having an opening corresponding to the shape of a conductive thin film described later was formed by a photolithography technique.

Then, the Cr film in the opening was removed by wet etching, and then the resist mask was removed with an organic solvent to form a Cr mask.

Step-d An alloy fine particle film having an average film thickness of 30 nm was formed by using the sputtering method. The target is Pd-5 at. % Zr
Using an alloy, the argon gas pressure was 130 Pa and the sputtering voltage was 2 KV.

Then, by wet etching, Cr
The alloy fine particle film was patterned by removing the mask and lifting off to form the conductive thin film 4 having a desired shape (FIG. 3B).

Step-e The above device was placed in the vacuum processing apparatus shown in FIG. 6 and subjected to a forming process to form an electron emitting portion. The inside of the vacuum container 11 was decompressed to about 1 × 10 ⁻³ Pa by an exhaust device 12 including a sorption pump and an ion pump, and a triangular wave pulse having a gradually increasing pulse peak value shown in FIG. 4B was applied. Then, the electron-emitting portion 5 was formed by the energization forming process.

At this time, the pulse width T1 = 1 msec. , The pulse interval T2 = 10 msec, a rectangular wave pulse having a peak value of 0.1 V was inserted during the rest period of the forming pulse, and the resistance value of the element was measured. When the resistance value was 1 MΩ or more, the forming treatment was performed. Ended (Fig. 3
(C)).

Step-f Subsequently, activation processing is performed. Introduce ZrCl ₄ into the vacuum vessel. At this time, the introduction amount is adjusted so that the pressure is about 5 × 10 ⁻¹ Pa. A pulse voltage was applied to the device for 30 minutes in this atmosphere. The applied pulse has a pulse width of 100 μsec. , Pulse interval T2 = 10 msec. The rectangular wave pulse of, and the pulse peak value was set to 15V.

By this treatment, both the device current If and the emission current Ie were found to increase.

With the above device installed, the device and the vacuum vessel were heated to about 150 ° C. and evacuated. With the vacuum container and the device returned to room temperature, the pressure is 1.3 × 10 ^-4 Pa
It was.

[Comparative Example 1] In the step of forming the conductive thin film in the step-d of Example 1 described above, a Pd target was used as the sputtering target and the thickness was 30 n.
A surface conduction electron-emitting device was produced by the same steps as in Example 1 except that a Pd fine particle film of m was formed.

For the devices of Example 1 and Comparative Example 1 described above, their electron emission characteristics and their changes with time were examined. The voltage applied to the element has a pulse width T1 = 100 μse
c. , Pulse interval 10 msec. With a rectangular wave pulse having a peak value of 15V. The distance between the electron-emitting device and the anode electrode was H = 15 mm, and the potential difference between the device and the anode was 1 KV.

Table 2 shows the values of the emission current Ie, the device current If, and the electron emission efficiency at the start of measurement and after continuous driving for a certain period for both devices.

[0155]

[Table 2]

After continuously driving the device of Example 1, an attempt was made to recover the characteristics by the following process.

The peak value of the voltage pulse applied to the device was set to 9 V without applying voltage to the anode, and the pulse was applied for 5 minutes. After this treatment, the electron emission characteristics were measured again. The emission current Ie was 3.7 μA, the device current If was 1.9 mA, and the electron emission efficiency was η = 0.19%. Was given.

Such a phenomenon is exhibited in a normal driving state, where the current density is large and the conditions are severe, and the low work function material portion on the surface cannot be recovered due to diffusion from the inside. It is presumed that this is because the application of a lower applied voltage causes recovery of the low work function material portion.

[Embodiment 2] The conductive thin film forming step of the step-d of the above-mentioned Embodiment 1 was performed by Pt-5at. % Ti alloy target and step of Example 1-f
The structure was the same as that of Example 1 except that TiCl ₄ was used as the introduction gas in the activation step.

[Comparative Example 2] The same procedure as in Example 2 was carried out except that the conductive thin film forming step of step-d of Example 2 was changed to the formation of a Pt fine particle film using a Pt target.

Under the same conditions as in Example 1 and Comparative Example 1, the electron emission characteristics of both devices and their changes with time were measured.
The results are shown in Table 3.

[0162]

[Table 3]

[Embodiment 3] The conductive thin film forming step of step-d of Example 1 is an alloy fine particle film forming step using an alloy target of Ni-7% Ti-4% Ir, and the step- A device was prepared under the same conditions as in Example 1 except that the gas introduced in the activation step of f was a mixed gas of TiCl ₄ and IrCl ₄ .

[Comparative Example 3] An element was manufactured under the same conditions as in Example 3 except that the conductive thin film forming step of step-d of Example 3 was a Ni fine particle film forming step using a Ni target. did.

The electron emission characteristics of the devices of Example 3 and Comparative Example 3 were measured under the same conditions as in Example 1. The electron emission characteristics of both devices and their changes with time were measured, and the results are shown in Table 4.

[0166]

[Table 4]

Although Ir does not have a low work function as compared with Ni, it has a high melting point and a small ionic radius, so that it diffuses and precipitates with Ti toward the electron emission portion and contributes to the improvement of stability. It is considered that

[Embodiment 4] A device electrode is formed on a quartz substrate in the same procedure as in Steps a to c of Example 1,
Further, a Cr mask having an opening corresponding to the shape of the conductive thin film was formed. Subsequently, step-d, a compound solution of organic Zr (zirconium 2,4 pentadione ethanol solution) is applied, and the temperature is 400 ° C. in the atmosphere.
Heat treatment was performed for 15 minutes. Subsequently, an organic Pd compound solution (ccp4230: manufactured by Okuno Chemical Industries Co., Ltd.) was applied, and heat treatment was performed at 300 ° C. for 12 minutes in the atmosphere.

Step-e The Cr mask is removed by wet etching, and a conductive thin film is formed by lift-off. Then, the conductive thin film is reduced by heat treatment at 150 ° C. in an H ₂ stream.
At this point, the conductive thin film is a mixed fine particle film of Pd fine particles and Zr fine particles.

Thereafter, the forming treatment and the activation treatment were carried out in the same manner as in step-e and step-f of Example 1.

When the electron emission characteristics of this element and its change with time were measured, almost the same results as in Example 1 were obtained.

[Examples 5 to 9 and Comparative Examples 5 and 6] The outline of the device of this example is the same as that shown in FIG. The device electrodes 2 and 3 are formed on the quartz substrate 1. Electrode spacing L is 3
μm, the electrode length W is 500 μm, and the thickness d is 1
It was set to 00 nm.

An Au—Cs electron emitting portion forming thin film is formed on this by an EB vapor deposition apparatus. At this time, a metal mask was used to form the thin film for forming the electron emitting portion over the electrodes 2 and 3 as shown in FIG. The thickness of the electron emission portion forming thin film was adjusted to 10 nm. The composition of the thin film for forming the electron emission portion was adjusted by the charged amount of the vapor deposition source, and the composition was determined by Auger electron spectroscopy.

The element thus prepared was set in the measuring device installed in the vacuum chamber. During the transfer from the vapor deposition apparatus to the measurement apparatus, the atmosphere of the element was vacuum or an inert gas, and care was taken to avoid contact with oxygen, water vapor, carbon dioxide, and the like.

The pressure in the vacuum chamber is about 1.3 × 10 ^-4 Pa. Prior to the measurement, the electron emitting portion 5 is formed.

A voltage is applied between the electrodes 2 and 3 to energize the thin film for forming the electron emitting portion to form the electron emitting portion 5.

Elements were prepared by changing the Cs content of the Au--Cs alloy, and the value of η was measured. When the Cs content was 8 atom% or more, the deterioration of the electron emission efficiency with time became large. Therefore, the effect of improving the electron emission efficiency was examined for the samples having the Cs content of 7 atom% or less. The results are shown in Table 5.

[0178]

[Table 5]

When the electron-emitting portions of the devices of the above Comparative Examples and Examples were observed, it was found that they were composed of fine particles having a particle size of about 10 nm. When these fine particles were observed with a high resolution transmission electron microscope, a contrast image that was considered to be an Au single crystal was seen in the comparative example, but in the case of the device of the example, a portion with different contrast was seen inside.

Considering the composition, it shows that the Au ₅ Cs phase having a hexagonal structure is precipitated in the Au phase forming the face-centered cubic lattice. Therefore, by including Au ₅ Cs in highly stable Au, this phase is kept stable, and due to thermal diffusion, Cs gradually moves to the surface of the fine particles to lower the work function of the fine particles. It is considered that this has brought about the effect of improving the electron emission efficiency.

When the content of Cs increases, the Au ₅ Cs phase appears directly on the surface of the fine particles and reacts with a small amount of H ₂ 0, CO _{2 and the} like remaining in the measuring device. It is thought that deterioration will occur.

[Examples 10 to 14 and Comparative Example 7] Using the Au-Ba alloy as the material for the electron emitting portion, devices were prepared in the same manner as above, and the electron emitting efficiency η was determined. When the Ba content exceeds 9 atom%, the electron emission efficiency deteriorates with time. Therefore, the effect of improving the electron emission efficiency was examined for the samples having the Ba content of 8 atom% or less. The results are shown in Table 6.

[0183]

[Table 6]

When the elements of the above Examples were observed with a transmission electron microscope in the same manner as above, it was found that the fine particles in the electron-emitting portion had a structure in which Au ₅ Ba phase was included in Au. all right.

[Examples 15 to 20 and Comparative Example 8] Using Au-Sr alloy as the material for the electron emitting portion, devices were prepared in the same manner as above, and the electron emitting efficiency η was determined. When the Sr content exceeds 9 atom%, the electron emission efficiency deteriorates with time. Therefore, the improvement effect of the electron emission efficiency was examined for the device having the Sr content of 8 atom% or less. The results are shown in Table 7.

[0186]

[Table 7]

[Examples 21 to 26, Comparative Examples 9 and 10] A Pt-Sr alloy was used as the material of the electron emission portion forming thin film. The structure of the element is almost the same as that of the above embodiment. Pt
The -Sr film was formed as a fine particle film by the gas evaporation method. The outline of the apparatus used for film formation is shown in FIG. This apparatus comprises a fine particle generation chamber 81, a fine particle deposition chamber 82, and a nozzle 83 connecting the two chambers. The element is set at the 84 position. The inside of the apparatus was once decompressed to 6.7 × 10 ⁻⁵ Pa by the exhaust apparatus 85, and then Ar gas was introduced into the fine particle generation chamber 81 through the gas inlet 86. At this time, the amount of Ar gas introduced was adjusted so that the pressure in the fine particle generation chamber 81 was 6.7 Pa. At this time, the pressure of the fine particle deposition chamber 82 was 1.3 × 10 ^-2 Pa. The diameter of the nozzle 83 is φ5m
m, and the nozzle-sample distance was set to 150 mm. The material of the electron emitting portion is contained in a crucible 87 made of alumina. A heater 88 made of tungsten is arranged around the crucible 87. As a result, the thin film material for forming the electron emitting portion which is resistance-heated and evaporated becomes fine particles,
It is blown out from the nozzle and deposited on the element. At this time, the film thickness of the fine particles is adjusted by opening and closing the shutter 89. If the Sr content exceeds 9 atom%, the electron emission efficiency deteriorates with time. Therefore, the effect of improving the electron emission efficiency was examined for the device having the Sr content of 8 atom% or less. The method of forming the electron emitting portion and the method of measuring the same are the same as those in the above-described embodiment. The results are shown in Table 8.

[0188]

[Table 8]

It was found by observation with a transmission electron microscope that the fine particles in the electron emitting portion had a structure in which Pt ₅ Sr was included in Pt.

[Examples 27 to 32, Comparative Example 11] A Pt-Ba alloy was used as the material of the thin film for forming the electron emitting portion, and the same method as in Comparative Examples 9 and 10 and Examples 21 to 26 was used.
It was formed as a fine particle film. For the same reason as above, B
The effect of improving the electron emission efficiency was examined for devices having an a content of 8 atomic% or less. The results are shown in Table 9.

[0191]

[Table 9]

It was found by observation with a transmission electron microscope that the fine particles in the electron emitting portion had a structure in which the Pt ₅ Ba phase was included in Pt.

[Examples 33 to 38, Comparative Examples 12 and 13]
Similar to the above Examples and Comparative Examples, after forming the device electrodes 2 and 3 on the quartz substrate 1, the conductive thin film 4 made of fine particles of palladium oxide was formed between the electrodes. The forming method is as follows.

Organopalladium compound (Okuno Pharmaceutical Co., Ltd.)
Co., Ltd., ccp-4230) was diluted with an organic solvent and applied with a spinner, followed by heat treatment at 300 ° C. for 10 minutes to obtain fine particles of palladium oxide (PdO) (average particle size: 7n).
m) was formed. The sheet resistance of this fine particle film was 5 × 10 ⁴ Ω / □.

Then, a suspension of dimethoxybarium (Ba (OCH ₃ ) ₂ ) dispersed in ethanol is spinner coated on the fine particle film, and then dried. This spinner coating and drying are repeated several times.

For comparison, a sample not coated with dimethoxybarium was also prepared at the same time.

Next, the above element was set in a measuring device in a vacuum chamber, the vacuum chamber was evacuated to about 1.3 × 10 ⁻⁴ Pa, and a voltage was applied between the electrodes 2 and 3. Conductive thin film 4
Then, the electron-emitting portion 5 was created by conducting an energization process (forming process). Figure 4 shows the voltage waveform of the forming process.
It shows in (a).

In FIG. 4, Tl and T2 are the pulse width and pulse interval of the voltage waveform, and in this embodiment, T1 is 1 mse.
c. , T2 for 10 msec. The peak value of the triangular wave (peak voltage during forming) was 5 V, and the forming treatment was performed for 60 seconds in a vacuum atmosphere of about 1.3 × 10 ⁻⁴ Pa. In the electron emitting portion 5 thus produced, fine particles containing palladium as a main component were dispersed and arranged, and the average particle diameter of the fine particles was 3 nm.

After that, the sample was transferred to an electric furnace and Ar-2 was used.
Heated to 300 ° C. in a flow of% H ₂ . By this treatment, palladium oxide is reduced to metal. The composition of this film was analyzed in the same manner as described above. The Ba content was adjusted by the number of spinner coats of the dimethoxybarium suspension. Table 10 shows the measurement results of the electron emission characteristics.

[0200]

[Table 10]

The fine particles in the electron emitting portion were found to have a structure in which the Pd ₅ Ba phase was included in Pd by observation with a transmission electron microscope.

[Embodiment 39] The following is an example of an electron source in which a plurality of the surface conduction electron-emitting devices of the above embodiments are arranged on a substrate and an image forming apparatus using the electron source. In addition, in this embodiment, the surface conduction electron-emitting device corresponding to the first embodiment is arranged, but the electron source and the image forming apparatus of the present invention are not limited to this. Not only those corresponding to the above-described embodiments but also any element as long as it is the surface conduction electron-emitting device of the present invention can be used as an electron source and an image forming apparatus similar to this embodiment. Is.

In the present embodiment, an electron as shown in FIG. 8 in which a large number of the surface conduction electron-emitting devices of the present invention shown in FIG. 2 are arranged in a simple matrix (20 rows and 60 columns including three colors). An example in which an image forming apparatus as shown in FIG. 9 is manufactured using a source will be described.

A plan view of a part of the electron source is shown in FIG. 18 is a sectional view taken along the line AA 'in FIG. However, in FIG.
7, FIG. 18, and FIG. 19, the same reference numerals indicate the same members.

Here, 21 is a substrate, 22 is an X-direction wiring (also called lower wiring), 23 is a Y-direction wiring (also called upper wiring), 4 is a conductive thin film, 2 and 3 are element electrodes, and 91 is an interlayer. The insulating layer 92 is a contact hole for electrically connecting the device electrode 2 and the lower wiring 22.

First, the method for manufacturing the electron source of this embodiment will be specifically described in the order of steps with reference to FIGS. The following steps a to h are (a) to (d) of FIG.
And (e) to (h) of FIG.

Step a: A substrate 21 having a 0.5 μm-thick silicon oxide film formed on the cleaned blue plate glass by a sputtering method is sequentially vacuum-deposited with a 5 nm-thick Cr film and a 600 nm-thick Au film. After stacking, photoresist (A
(Z1370; manufactured by Hoechst Co.) is spin-coated by a spinner and baked, and then a photomask image is exposed and developed to form a resist pattern of the lower wiring 22, and the Au / Cr deposited film is wet-etched to have a desired shape. Lower wiring 22
Was formed.

Step b: Next, an interlayer insulating layer 91 made of a silicon oxide film having a thickness of 1.0 μm was deposited by the RF sputtering method.

Step c: A photoresist pattern for forming the contact hole 92 is formed in the silicon oxide film deposited in the step b, and the interlayer insulating layer 91 is etched by using this as a mask to form the contact hole 92. The etching is performed by RIE (React) using CF ₄ and H ₂ gas.
iv Ion Eching) method.

Step d: After that, a pattern to be the device electrodes 2 and 3 and the gap L between the device electrodes is formed by a photoresist (RD-2000N-41: manufactured by Hitachi Chemical Co., Ltd.), and a film having a thickness of 5 nm is formed by a vacuum deposition method. Ti, thickness 100
nm of Ni was sequentially deposited. After that, the photoresist was dissolved in an organic solvent and the Ni / Ti deposited film was lifted off.
The device electrode interval L was 3.0 μm, and the device electrode length W was 300 μm.

Process e: Upper wiring 23 on the device electrodes 2 and 3
After forming the photoresist pattern of
i and Au having a thickness of 500 nm were sequentially deposited by vacuum evaporation, and unnecessary portions were removed by lift-off to form the upper wiring 23 having a desired shape.

Step f: A Cr film 93 having a film thickness of 10 nm is deposited and patterned by vacuum evaporation, and the step-d of Example 1 is performed.
Under the same conditions as for Pd-5 at. % Zr alloy fine particle film was deposited.

Step g: The Cr film 93 was re-etched with an acid etchant and lifted off to form the conductive thin film 4 having a desired pattern shape. This conductive thin film 4
Had a thickness of 30 nm.

Step h: A resist was applied to the entire surface, exposed using a mask and developed to remove the resist only from the contact hole 92 portion. After that, Ti having a thickness of 5 nm and Au having a thickness of 500 nm were sequentially deposited by vacuum deposition, and unnecessary portions were removed by lift-off to fill the re-contact hole 92.

Through the above steps, the lower wiring 2 is formed on the substrate 1.
2, the interlayer insulating layer 91, the upper wiring 23, the device electrodes 2 and 3, the conductive thin film 4 and the like were formed to obtain an unformed electron source.

A surface image forming apparatus was manufactured using the unformed electron source manufactured as described above. The manufacturing procedure will be described below with reference to FIGS. 9 and 10.

First, after fixing the substrate 21 of the unformed electron source on the rear plate 31, the substrate 21
A face plate 36 (configured by forming a fluorescent film 34, which is an image forming member, and a metal back 35 on the inner surface of the glass substrate 33) is arranged over the support frame 32, and the face plate 36, Frit glass was applied to the joint portion of the support frame 32 and the rear plate 31, and baked at 400 ° C. for 10 minutes in the atmosphere to seal the frit glass. The frit glass was also used to fix the substrate 21 to the rear plate 31.

Fluorescent film 34 which is an image forming member
In order to realize color, the stripe shape (see FIG.
(See (a)), black stripes are first formed, and the phosphors 39 of the respective colors are formed in the gaps by the slurry method.
Was applied to produce a fluorescent film 34. As a material for the black stripe, a material containing graphite as a main component, which is often used, was used.

A metal back 35 is provided on the inner surface side of the fluorescent film 34. The metal back 35 was produced by performing a smoothing process (usually called filming) on the inner surface of the fluorescent film 34 after producing the fluorescent film 34, and then vacuum-depositing A1. In order to further increase the conductivity of the face plate 36, a transparent electrode may be provided on the outer surface side of the fluorescent film 34, but in this embodiment, the metal back 35 is used.
Since sufficient conductivity was obtained only by itself, it was omitted.

At the time of performing the above-mentioned sealing, in the case of a color, each color phosphor 39 and the surface-conduction-type dragonfly-emitting device 24 have to correspond to each other, so that sufficient alignment is performed.

After the inside of the envelope 37 completed as described above is sufficiently evacuated, a pulse voltage is applied between the device electrodes 2 and 3 through the external terminals Dox1 to Doxm and Doyl to Doyn to form a conductive thin film. The electron emitting portion 5 was formed by performing the forming process.

Thereafter, as in the first embodiment, Z is placed in the envelope.
The activation treatment was carried out by introducing rCl ₄ .

Subsequently, a stabilization process was performed. Envelope 37
Exhaust while heating to 120 ℃, internal pressure 4.2 ×
After the pressure was set to 10 ⁻⁴ Pa, an exhaust pipe (not shown) was welded by heating with a gas burner to seal the envelope 37. Finally, in order to maintain the degree of vacuum after sealing, a getter process was performed by a high frequency heating method. In the image display device of the present invention completed as described above, each of the electron-emitting devices is connected to the external terminals Dox1 to Doxm, Doy1 to Doyn,
Electrons are emitted by applying a scanning signal and a modulation signal to the electron-emitting devices 24 from signal generating means (not shown), and a high voltage of several KV is applied to the metal back 35 through the high-voltage terminal Hv to accelerate the electron beam. , Fluorescent film 3
Image display was performed by colliding with No. 4 and exciting and emitting light.

[Embodiment 40] FIG. 5 is a block diagram of an image forming apparatus according to an embodiment 39 of the present invention so that it can display image information provided by various image information sources such as television broadcasting. It is a figure for showing an example of a display.

In the figure, 201 is an image display device, 1001 is a drive circuit for the image display device, 1002 is a display controller, 1003 is a multiplexer, 1004 is a decoder, 1005 is an input / output interface circuit, and 1006.
Is a CPU, 1007 is an image generation circuit, 1008 and 10
09 and 1010 are image memory interface circuits, 1011 are image input interface circuits, 101
2 and 1013 are TV signal receiving circuits and 1014 is an input unit.

When receiving a signal including both video information and audio information, such as a television signal, the present image forming apparatus naturally reproduces audio at the same time as displaying video. Descriptions of circuits, speakers, and the like relating to reception, separation, reproduction, processing, storage, etc. of audio information that are not directly related to the features of the present invention will be omitted.

The functions of the respective parts will be described below in accordance with the flow of the image signal.

First, the TV signal receiving circuit 1013 is a circuit for receiving a TV signal transmitted using a wireless transmission system such as radio waves or spatial optical communication.

The TV signal system to be received is not particularly limited. For example, NTSC system, PAL system, SEC.
Any method such as AM method may be used. Further, a TV signal including a larger number of scanning lines than these, for example, a so-called high-definition TV such as the MUSE system is suitable for taking advantage of the image display device suitable for a large area and a large number of pixels. It is a signal source.

[0230] T received by the TV signal receiving circuit 1013
The V signal is output to the decoder 1004.

The TV signal receiving circuit 1012 is a circuit for receiving a TV signal transmitted using a wire transmission system such as a coaxial cable or an optical fiber. Similar to the TV signal receiving circuit 1013, the system of the TV signal to be received is not particularly limited, and the TV signal received by this circuit is also output to the decoder 1004.

Image input interface circuit 1011
Is a circuit for capturing an image signal supplied from an image input device such as a TV camera or an image reading scanner, and the captured image signal is output to the decoder 1004.

Image memory interface circuit 101
Reference numeral 0 is a circuit for capturing an image signal stored in a video tape recorder (hereinafter abbreviated as VTR), and the captured image signal is output to the decoder 1004.

Image memory interface circuit 100
Reference numeral 9 is a circuit for fetching the image signal stored in the video disc, and the fetched image signal is the decoder 1
It is output to 004.

Image memory interface circuit 100
Reference numeral 8 denotes a circuit for capturing an image signal from a device that stores still image data, such as a still image disk, and the captured still image data is input to the decoder 1004.

The input / output interface circuit 1005 is
It is a circuit for connecting the display device to an external computer, a computer network, or an output device such as a printer. It is of course possible to input / output image data and character / graphic information, and in some cases, input / output control signals and numerical data between the CPU 1006 of the image forming apparatus and the outside. .

The image generation circuit 1007 receives image data, character / graphic information, or the CPU 100 which is externally input via the input / output interface circuit 1005.
6 is a circuit for generating display image data on the basis of the image data and character / graphic information output from FIG. Inside this circuit, for example, a rewritable memory for storing image data and character / graphic information, a read-only memory that stores image patterns corresponding to character codes, a processor for image processing, etc. , And the circuits necessary for image generation are incorporated.

The display image data generated by this circuit is output to the decoder 1004, but in some cases, it can be output to an external computer network or printer via the input / output interface circuit 1005.

The CPU 1006 mainly carries out operations relating to operation control of the display device and generation, selection and editing of a display image.

For example, a control signal is output to the multiplexer 1003 to appropriately select or combine image signals to be displayed on the image display device. In that case, a control signal is generated to the image display device controller 1002 according to the image signal to be displayed, and the display device such as the screen display frequency, the scanning method (for example, interlaced or non-interlaced), the number of scanning lines in one screen, etc. The operation of is controlled appropriately. Also,
For the image generation circuit 1007, image data, characters,
The graphic information is directly output, or an external computer or memory is accessed through the input / output interface circuit 1005 to input image data or character / graphic information.

It should be noted that the CPU 1006 may be involved in work for other purposes. For example, it may be directly related to a function of generating and processing information, such as a personal computer or a word processor. Alternatively, as described above, the input / output interface circuit 1005
It is also possible to connect to an external computer network via the, and perform work such as numerical calculation in cooperation with an external device.

The input unit 1014 is used by the user to input commands, programs, data, etc. to the CPU 1006. For example, various input devices such as a keyboard, a mouse, a joystick, a bar code reader, and a voice recognition device can be used. An input device can be used.

The decoder 1004 converts various image signals input from the above 1007 to 1013 into three primary color signals,
Alternatively, it is a circuit for inverse conversion into a luminance signal, an I signal, and a Q signal. In addition, as shown by a dotted line in the figure, the decoder 100
4 is preferably equipped with an image memory inside. This is for handling a television signal which requires an image memory for reverse conversion, for example, including the MUSE system.

The provision of the image memory makes it easy to display a still image. Alternatively, the image generation circuit 1007
And the CPU 1006 in cooperation with the image thinning, interpolation,
This has the advantage that image processing and editing including enlargement, reduction, and composition are facilitated. Multiplexer 1003
Is for appropriately selecting a display image based on a control signal input from the CPU 1006. That is, the multiplexer 1003 selects a desired image signal from the inversely converted image signals input from the decoder 1004 and outputs it to the drive circuit 1001. In that case, by switching and selecting image signals within one screen display time,
It is also possible to divide one screen into a plurality of areas and display different images depending on the areas, as in a so-called multi-screen television.

The image display device controller 1002 is a circuit for controlling the operation of the drive circuit 1001 based on the control signal input from the CPU 1006.

As one related to the basic operation of the image display device, for example, a power source for driving the image display device (not shown)
The drive circuit 10 supplies signals for controlling the operation sequence of
Output to 01. As a signal relating to the driving method of the image display device, for example, a signal for controlling a screen display frequency and a scanning method (for example, interlace or non-interlace) is output to the drive circuit 1001. In some cases, a control signal relating to image quality adjustment such as brightness, contrast, color tone, and sharpness of a display image may be output to the drive circuit 1001.

The drive circuit 1001 is used in the image display device 201.
Is a circuit for generating a drive signal to be applied to the image display device and operates based on an image signal input from the multiplexer 1003 and a control signal input from the image display device controller 1002.

The functions of the respective parts have been described above . With the configuration illustrated in FIG. 5 , the image information input from various image information sources in the image forming apparatus is used in the image display apparatus 201.
It is possible to display. That is, various image signals such as television broadcast are inversely converted by the decoder 1004, appropriately selected by the multiplexer 1003, and input to the drive circuit 1001. On the other hand, the display controller 1002 generates a control signal for controlling the operation of the drive circuit 1001 according to the image signal to be displayed. The drive circuit 1001 applies a drive signal to the image display device 201 based on the image signal and the control signal. As a result, the image is displayed on the image display device 201. These series of operations are performed by the CPU 1006.
Is controlled comprehensively by.

In this image forming apparatus, the image memory built in the decoder 1004 and the image generating circuit 100 are included.
7 and information not only selected but also displayed image information such as enlargement, reduction, rotation, movement, edge enhancement, thinning, interpolation, color conversion, image aspect ratio conversion, etc. It is also possible to perform initial image processing and image editing including synthesizing, erasing, connecting, replacing, and fitting. Although not particularly mentioned in the description of this embodiment, a dedicated circuit for processing and editing audio information may be provided as in the above-mentioned image processing and image editing.

Therefore, the present image forming apparatus is applicable to a display device for television broadcasting, a terminal device for a video conference, an image editing device for handling still images and moving images, a terminal device for a computer,
It is possible to combine the functions of office terminals such as word processors, game machines, etc., with a very wide range of applications for industrial or consumer use.

The display device shown in FIG . 5 can be modified in various ways based on the technical idea of the present invention. For example, among the components shown in FIG. 5 , circuits relating to functions that are unnecessary for the purpose of use may be omitted. On the contrary, the constituent elements may be added depending on the purpose of use. For example,
When this display device is applied as a videophone, it is preferable to add a television camera, a voice microphone, an illuminator, a transmission / reception circuit including a modem, and the like to the components.

In the present display device, the depth of the display device can be reduced because the image display device using the surface conduction electron-emitting device as an electron beam source can be easily thinned. In addition, since it is easy to increase the area, has high brightness, and has excellent viewing angle characteristics, this display device can display a highly realistic image with high visibility with good visibility.

Further, by using the electron beam source of the present invention having a uniform and stable electron emission characteristic, a high-quality color flat television excellent in color reproducibility without variation was realized.

[0254]

As described above, according to the present invention, an electron-emitting device, an electron source, which stably exhibits preferable electron-emitting characteristics,
An image display device capable of stable and excellent image display can be realized.

[Brief description of drawings]

FIG. 1 is a schematic diagram for explaining a structure in the vicinity of an electron emitting portion of an element according to an embodiment of the electron emitting element of the present invention.

FIG. 2 is a schematic diagram for explaining the overall configuration of a conventional surface conduction electron-emitting device that the present invention covers.

FIG. 3 is a schematic diagram for explaining a manufacturing process of the surface conduction electron-emitting device of the present invention.

FIG. 4 is a diagram for explaining the waveform of the pulse voltage applied between the element electrodes during the energization forming process in the manufacturing process of the present invention.

FIG. 5 shows various types of image forming apparatuses using the image forming apparatus of the present invention .
The structure of a system that processes image input signals and displays images.
It is a block diagram showing an example of composition.

FIG. 6 is a schematic diagram showing a configuration of a vacuum processing apparatus used for manufacturing the surface conduction electron-emitting device of the present invention and measuring electron emission characteristics.

FIG. 7 is a diagram for explaining electron emission characteristics of the surface conduction electron-emitting device of the present invention.

FIG. 8 is a schematic diagram for explaining matrix wiring of the electron source of the present invention.

FIG. 9 is a schematic diagram showing a configuration of an image forming apparatus of the present invention using an electron source having matrix wiring.

FIG. 10 is a schematic diagram showing an example of a pattern of a fluorescent film used in the image forming apparatus of the present invention.

FIG. 11 is a diagram showing an example of a circuit block for displaying an image by an NTSC image signal using the image forming apparatus of the present invention.

FIG. 12 is a schematic view showing a configuration of a vacuum processing apparatus used for manufacturing the image forming apparatus of the present invention.

FIG. 13 is a schematic diagram showing a configuration of a circuit used in forming processing and activation processing in manufacturing the electron source and the image forming apparatus of the present invention.

FIG. 14 is a schematic diagram for explaining a ladder-type wiring of the electron source of the present invention.

FIG. 15 is a schematic diagram showing a configuration of an image forming apparatus of the present invention using an electron source having a ladder type wiring.

FIG. 16 is a schematic view showing a configuration of an apparatus for depositing a fine particle film, which is used for manufacturing the surface conduction electron-emitting device of the present invention.

FIG. 17 is a partial plan view schematically showing the configuration of an electron source having matrix wiring.

18 is a diagram schematically showing a configuration of a cross section taken along line AA in FIG.

FIG. 19 is a schematic view for explaining the manufacturing process of the electron source having the matrix wiring.

FIG. 20 is a schematic diagram for explaining a manufacturing process of an electron source having matrix wiring.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Substrate 2 and 3 Element electrode 4 Conductive thin film 5 Electron emission part 11 Vacuum container 12 Exhaust pump 13 Power supply 14 for applying element voltage Vf to an electron emission element 14 For measuring the element current If flowing through the electroconductive thin film 4 Ammeter 15 Anode electrode 16 High-voltage power supply 17 for applying voltage to the anode electrode Ammeter 21 for measuring the emission current Ie emitted from the electron emission unit 5 Electron source substrate 22 X-direction wiring 23 Y-direction wiring 24 Surface Conductive electron-emitting device 25 Connection 26 Common wiring 31 Rear plate 32 Support frame 33 Glass substrate 34 Fluorescent film 35 Metal back 36 Face plate 37 Enclosure 38 Black conductive material 39 Fluorescent substance 51 Common electrode 52 Power source 53 Row selection means 61 Image Display device 62 Scanning circuit 63 Control circuit 64 Shift register 65 Line memory 66 Synchronous signal separation circuit 6 Modulation signal generator Vx, Va DC voltage source 71 Grid electrode 72 Electron passage opening 81 Particle generation chamber 82 Particle deposition chamber 83 Nozzle 84 Element substrate 85 Exhaust device 86 Gas inlet 87 Crucible 88 Heater 89 Shutter 91 Interlayer insulation Layer 92 Contact hole 93 Cr film

Front page continuation (72) Inventor Takeo Tsukamoto 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Shigeki Yoshida 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Takao Kusaka 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (56) Reference JP-A-6-203741 (JP, A) JP-A-6-203742 (JP, A) ) JP-A-7-65699 (JP, A) JP-A-1-93024 (JP, A) JP-A-9-265903 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H01J 1/316 H01J 9/02

Claims (10)

(57) [Claims] 1. A pair of device electrodes facing each other on a substrate,
In an electron-emitting device having a conductive thin film in electrical contact with both of the pair of device electrodes and an electron-emitting portion formed in a part of the conductive thin film, the conductive thin film is formed of fine particles, A first metal element which is a main constituent element,
A conductive thin film, which contains one or more second metal elements that form a low work function material portion on the surface of the conductive thin film ;
The ionic radius of the most stable ion of the first metal element is
The ion radius of the most stable ion of the second metal element
Ri is large, by a current between the pair of device electrodes, said second metal element, the internal conductive film, an electron emission device characterized by moving at least a portion of the conductive thin film surface. 2. The electron-emitting device according to claim 1, wherein the conductive thin film is composed of fine particles made of an alloy containing the first metal element and the second metal element. Electron emitting device. 3. The electron-emitting device according to claim 1, wherein the conductive thin film contains fine particles substantially made of the first metal element and fine particles substantially made of the second metal element. An electron-emitting device characterized by the above. 4. A device row in which a plurality of electron-emitting devices according to any one of claims 1 to 3 are arranged in one direction on a substrate,
An electron source having one row or a plurality of rows and having a wiring for driving the electron-emitting device. 5. The electron source according to claim 4 , wherein the wiring is a ladder wiring. 6. The electron source according to claim 4 , wherein the wirings are arranged in a matrix. 7. An image is formed by irradiating a desired pixel with the electron source according to any one of claims 4 to 6 and irradiating a desired pixel with the electron beam emitted from the electron source in a vacuum container. An image forming apparatus including an image forming member. 8. An image is formed by irradiating a desired pixel with the electron source according to any one of claims 4 to 6 and irradiating a desired pixel with the electron beam emitted from the electron source in a vacuum container. An image forming apparatus comprising an image forming member and an electron beam modulating means for modulating an electron beam applied to the image forming member based on an input signal. 9. The image forming apparatus according to claim 7, wherein the image forming member is a phosphor film containing a phosphor. 10. A method of restoring the characteristics of the electron-emitting device or an electron source or an image forming apparatus according to any one of claims 1 to 9 in the electron-emitting device, for the device current of the electron-emitting devices A characteristic recovery method characterized by applying a voltage higher than a threshold voltage and lower than an applied voltage during normal electron emission driving.