JP2000200545A - Electron emitting element, electron source, and method of manufacturing image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the more even and stabilized electron emitting characteristic by applying the pulse-like voltage to a conductive film arranged on a substrate in the atmosphere including the reducing material, and forming the conductive film with an electron emitting part. SOLUTION: A flat surface transmission type electron emitting element is formed of a substrate 1, element electrodes 4, 5, a conductive film 3 and an electron emitting part 2. In a process for manufacturing this element, the board 1 provided with the element electrodes 4, 5 is coated with the organic metal solution so as to form an organic metal film, and thereafter, heating for burning is performed so as to form a conductive film 3 made of the metal oxide. Continuously, when the forming process for feeding the current from the predetermined power source is performed between the element electrodes 4, 5, the conductive film 3 is partially formed with a part, of which structure is changed by breakdown, deformation and deterioration. This part forms the electron emitting part 2. This electrical feeding forming process is performed in the atmosphere including the reducing material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an electron-emitting device, a method for manufacturing an electron source having a large number of electron-emitting devices, and a display device and an exposure device using the electron source. The present invention relates to a method for manufacturing an image forming apparatus.

[0002]

2. Description of the Related Art Conventionally, two types of electron-emitting devices are known, namely, a thermionic electron-emitting device and a cold cathode electron-emitting device. Field emission type (hereinafter, referred to as "FE")
Type ". ), Metal / insulating layer / metal type (hereinafter referred to as “MI
M type ". ) And surface conduction electron-emitting devices.

[0003] As an example of the FE type, W. P. Dyke
and W. W. Dolan, "Field Em
issue ", Advance in Elect
ron Physics, 8, 89 (1956) or C.I. A. Spindt, “Physical
Properties of thin-filmfi
eld emission cathodes wit
h molybdenum cones ", JA
ppl. Phys. , 47, 5248 (1976).
And the like are known.

As an example of the MIM type, C.I. A. Mea
d, “Operation of Tunnel-Em
issue Devices ", J. Appl.
Phys. , 32, 646 (1961).

As an example of the surface conduction electron-emitting device,
M. I. Elinson, Radio Eng.
Electron Phys. , 10, 1290 (1
965).

[0006] The surface conduction electron-emitting device utilizes a phenomenon in which electrons are emitted by passing a current through a small-area thin film formed on an insulating substrate in parallel with the film surface. Examples of the surface conduction electron-emitting device include a device using an SnO ₂ thin film by Elinson et al. And a device using an Au thin film [G. Dittmer: "Thin Solid
Films ", 9,317 (1972)] , In 3 O 2
/ SnO ₂ thin film [M. Hartwell a
nd C.I. G. FIG. Fonstad: “IEEE Tran
s. ED Conf. , 519 (1975)], and those based on carbon thin films [Hisashi Araki et al .: Vacuum, Vol. 26, No. 1, p. 22 (1983)] and the like have been reported.

As a typical example of these surface conduction electron-emitting devices, the above-mentioned M.P. Figure 1 shows the device configuration of Hartwell
FIG. In the figure, reference numeral 1201 denotes a substrate. Reference numeral 1203 denotes a conductive film made of a metal oxide thin film or the like formed in an H-shaped pattern, and the electron emission portion 1202 is formed by an energization process called energization forming described below. The interval L in the figure is 0.5 to 1 mm, W '
Is set at 0.1 mm.

In these surface conduction electron-emitting devices, the electron-emitting portion 12 is subjected to an energization process called energization forming before the electron emission.
02 is generally formed. That is, the energization forming means that a voltage is applied to both ends of the conductive film 1203 and energized to locally break, deform or alter the conductive film 1203 to change the structure, and to form an electron in an electrically high-resistance state. This is a process for forming the emission unit 1202. Note that a crack is generated in a part of the conductive film 1203 in the electron emitting portion 1202, and electrons are emitted from the vicinity of the crack.

The above-described M.P. Apart from the Hartwell device,
The present applicant has formed a pair of opposing element electrodes formed of a conductor on an insulating substrate, formed a conductive film connecting the two electrodes separately from these electrodes, and formed an electron by electric current forming. A device having a structure in which an emission portion is formed is reported. It is also reported that a method of applying a pulse voltage and gradually increasing the peak value of the pulse can be applied as a method of the energization forming. An example of such a configuration and method is described in, for example, the specification of Japanese Patent Application No. 6-141670.

The above-mentioned surface conduction electron-emitting device has an advantage that a large number of devices can be arrayed over a large area because of its simple structure. Therefore, various applications for utilizing this feature are being studied. For example, a charged beam source,
Application to an image forming apparatus such as a display device is exemplified.

Conventionally, as an example in which a large number of surface conduction electron-emitting devices are arrayed, surface conduction electron-emitting devices are arranged in parallel, and both ends (both device electrodes) of each surface conduction electron-emitting device are wired. (Also referred to as a common wiring). An electron source in which rows each connected by a common line (also referred to as a ladder-type arrangement) are provided (for example, JP-A-64-31332, JP-A-1-283737, 2-257552).

In particular, in the case of a display device, a flat panel display device similar to a display device using liquid crystal can be used, and a self-luminous display device that does not require a backlight is a surface-conduction type electron-emitting device. There has been proposed a display device in which an electron source in which a number of elements are arranged and a phosphor that emits visible light when irradiated with an electron beam from the electron source are combined (US Pat. No. 5,066,883).

[0013]

With respect to the electron-emitting device, furthermore, the image forming apparatus to which the electron-emitting device is applied is further improved so as to stably provide a uniform image with little variation in luminance between pixels constituting a display image. There is a need for improved uniformity and stability of release characteristics.

However, the above-mentioned M.P. In the Hartwell electron-emitting device, satisfactory electron emission uniformity and stability have not always been obtained. Specifically, since the shape of the electron-emitting portion formed by the above-described forming process is not uniform over the entire electron-emitting portion, a plurality of such elements are arranged on a substrate, and for example, a flat image forming device is formed. When an electron source used for a device or the like is formed, the shape of the electron emitting portion is not uniform among a plurality of elements, and it is considered that it is difficult to perform uniform electron emission even at the electron emission characteristic. Therefore, it must be said that it is extremely difficult to provide an image forming apparatus which is uniform and has excellent operation stability by using this.

On the other hand, according to the electron-emitting device and the manufacturing method thereof reported by the present applicant, the above problems can be considerably improved, and the electron source and the image forming apparatus using the same can also be improved. Examples are also reported in the application.

However, in order to use it for more advanced applications, it is required to further improve the uniformity and stability of the electron emission characteristics. In particular, in the process of manufacturing an electron source in which a large number of surface conduction electron-emitting devices are arranged, in the process of forming an electron-emitting portion by energization forming, relatively large power is required, and therefore, the current flowing through the wiring is also large. . For this reason, a voltage drop occurs due to the electric resistance of the wiring, and the effective voltage applied to the electron-emitting devices in the forming step differs for each device. For this reason, a non-negligible difference may occur in the electron emission characteristics of each element.

In addition, since a large amount of electric power is required to form the electron-emitting device, the electron-emitting portion is not necessarily formed in a preferable state, and sufficient electron-emitting characteristics such as electron-emitting efficiency may not be obtained. is there.

An object of the present invention is to solve the above-mentioned technical problems to be solved and to provide an electron-emitting device having more uniform and stable electron-emitting characteristics, and an electron source provided with many such electron-emitting devices. Another object of the present invention is to provide an image forming apparatus which is more uniform, has excellent operation stability, and can form a higher quality image.

[0019]

The configuration of the present invention made to achieve the above object is as follows.

That is, a first aspect of the present invention is a method for manufacturing an electron-emitting device, comprising the steps of: disposing a conductive film on a substrate;
In an atmosphere containing a reducing substance, by applying a pulsed voltage to the conductive film to form an electron emitting portion in the conductive film, It relates to a manufacturing method.

The method for manufacturing an electron-emitting device according to the present invention includes:
As a further feature, "the reducing substance is H ₂ , CO
Or a substance selected from organic substances. "
"The pulse voltage is applied a plurality of times at predetermined intervals.""When the pulse width of the pulse voltage is T ₁ and the interval period is T ₂ , T ₂ Satisfies ≧ 5 × T ₁ , “the peak value of the pulse voltage applied to the conductive film gradually increases”, “the wave of the pulse voltage applied to the conductive film The high value gradually increases to a predetermined value, and is thereafter maintained at a constant value. "," The peak value of the pulsed voltage applied to the conductive film is maintained at a predetermined value. "After the energizing step, the method further includes a step of arranging carbon or a carbon compound or a metal or a metal compound in the electron-emitting portion." Compound or metal or metallization Objects, placing the electron emission regions,
In an atmosphere containing an organic substance or in an atmosphere containing a metal compound, this is a step of applying a current to the conductive film, '' and `` the energization in the atmosphere containing the organic substance or in the atmosphere containing the metal compound is This is a step of repeatedly applying a pulse-like voltage. "

According to a second aspect of the present invention, there is provided a method of manufacturing an electron source having a plurality of electron-emitting devices, wherein the electron-emitting device is manufactured by the first method of the present invention. To a method for producing the source.

Further, a third aspect of the present invention is a method for manufacturing an image forming apparatus having an electron source and an image forming member,
The present invention relates to a method for manufacturing an image forming apparatus, wherein the electron source is manufactured by the second method of the present invention.

According to the method for manufacturing an electron-emitting device and the electron source of the present invention, an electron-emitting device and an electron source capable of emitting electrons more uniformly and stably over a plurality of devices can be obtained. Also,
According to the method of manufacturing an image forming apparatus of the present invention, it is possible to obtain an image forming apparatus capable of displaying a good image with little variation and excellent operation stability.

[0025]

Next, preferred embodiments of the present invention will be described.

The electron-emitting devices applicable to the present invention are classified into the cold cathode type electron-emitting devices described above, and among them, from the viewpoint of the electron-emitting characteristics and the like, particularly the surface conduction type electron-emitting devices. Is preferred. Therefore, a surface conduction electron-emitting device will be described below as an example.

The basic structure of the surface conduction electron-emitting device applicable to the present invention is roughly classified into two types: a plane type and a vertical type. First, a basic configuration of a planar surface conduction electron-emitting device will be described.

FIGS. 1A and 1B are schematic views showing a configuration example of a plane type surface conduction electron-emitting device applicable to the present invention. FIG. 1A is a plan view, and FIG. FIG. FIG.
In the figures, 1 is a substrate (base), 4 and 5 are electrodes (element electrodes), 3 is a conductive film, and 2 is an electron-emitting portion.

Examples of the substrate 1 include quartz glass, glass having a reduced impurity content such as Na, blue plate glass, a laminate of blue plate glass with SiO ₂ laminated thereon by sputtering or the like, ceramics such as alumina, and a Si substrate. Can be used.

The material of the opposing device electrodes 4 and 5 is as follows.
General conductor materials can be used, for example, Ni, C
metals or alloys such as r, Au, Mo, W, Pt, Ti, Al, Cu, Pd and Pd, Ag, Au, RuO ₂ , Pd
Metal or metal oxide and printed conductor composed of glass or the like, such as -ag, is appropriately selected from a semiconductor conductive materials such as transparent conductor and polysilicon or the like In ₂ O ₃ -SnO _2.

The element electrode interval L, the element electrode length W ₁ , the width W ₂ and the thickness of the conductive film 3 are designed in consideration of the applied form and the like. The element electrode interval L can be preferably in the range of several hundred nm to several hundred μm, and more preferably several μm in consideration of the voltage applied between the element electrodes.
To several tens of μm.

The length W _{1 of the} device electrode can be in the range of several μm to several hundred μm in consideration of the resistance value of the electrode and the electron emission characteristics. The film thickness d of the device electrodes 4 and 5 can be in the range of several tens nm to several μm.

In addition to the configuration shown in FIG.
A configuration in which the conductive film 3 and the opposing element electrodes 4 and 5 are laminated on the above in this order can also be adopted.

The main materials constituting the conductive film 3 include:
For example, Pd, Pt, Ru, Ag, Au, Ti, In, C
u, Cr, Fe, Zn, Sn, Ta, W, and Pb, _{etc., PdO, SnO 2, In 2} O 3, PbO, oxides such as _{Sb 2 O 3, HfB 2,} ZrB 2, LaB 6, CeB ₆ , YB
_4, GdB boride such as _{4, TiC, ZrC, HfC,} Ta
Carbides such as C, SiC, WC, TiN, ZrN, Hf
Examples include nitrides such as N, semiconductors such as Si and Ge, and carbon.

As the conductive film 3, it is preferable to use a fine particle film composed of fine particles in order to obtain good electron emission characteristics. The film thickness is appropriately set in consideration of step coverage for the device electrodes 4 and 5, a resistance value between the device electrodes 4 and 5, a forming condition described later, and the like. The thickness of the conductive film 3 is preferably several to several hundreds of nm, and a film formed with a resistance value Rs of 10 ² to 10 ⁷ Ω / □ is preferably used. . Rs is a resistance R measured in the length direction of a thin film having a width of w and a length of l.
Is set as R = Rs (l / w). The film thickness showing the above-mentioned resistance value is in the range of about 5 nm to 50 nm, and in this film thickness range, the thin film of each material has the form of a fine particle film. The fine particle film described here is a film in which a plurality of fine particles are aggregated, and has a fine structure not only in a state in which the fine particles are individually dispersed and arranged, but also in a state in which the fine particles are adjacent to each other or overlap each other (some fine particles may To form an island-like structure as a whole). The particle size of the fine particles is in the range of several to several hundreds of nm, preferably in the range of 1 to 20 nm.

It should be noted that the term "fine particles" is frequently used in this specification, and its meaning will be described.

Small particles are called "fine particles", and smaller ones are called "ultra fine particles". Particles smaller than "ultrafine particles" and having a few hundred atoms or less are widely called "clusters".

However, each boundary is not strict and varies depending on what kind of property is focused on. Further, “fine particles” and “ultrafine particles” may be collectively referred to as “fine particles”, and the description in this specification is in line with this.

For example, in “Experimental Physics Course 14: Surfaces and Particles” (edited by Yoshio Kinoshita, published on September 1, 1986 by Kyoritsu Publishing Co., Ltd.) And especially when it is referred to as ultrafine particles, the particle size is about 10 nm to 2-3 n.
It means up to about m. It is not exactly strict because both are collectively written as fine particles, but it is a rough guide. When the number of atoms constituting a particle is two to several tens to several hundreds, it is called a cluster. (Page 195, lines 22 to 26).

In addition, the definition of “ultrafine particles” in the “Hayashi / Ultrafine Particle Project” of the New Technology Development Corporation was that the lower limit of the particle size was even smaller, as follows.

In the "Ultra Fine Particle Project" of the Creative Science and Technology Promotion System (1981 to 1986), a particle having a size (diameter) in the range of about 1 to 100 nm is called an "ultra fine particle". Then, one ultrafine particle is about 100-
It is an aggregate of about 10 ⁸ atoms. Ultra-fine particles are large to giant particles on an atomic scale. ("Ultra Fine Particles-Creative Science and Technology" Hayashi Tax, Ryoji Ueda, Akira Tazaki
(Edited by Mita Publishing, 1988, page 2, lines 1 to 4) /
"A particle even smaller than an ultrafine particle, that is, a single particle composed of several to several hundred atoms, is usually called a cluster" (ibid., Page 2, lines 12 to 13).

[0042] Based on the general notation as described above,
In the present specification, “fine particles” are an aggregate of a large number of atoms and molecules, and the lower limit of the particle size is several Å to 1 nm, and the upper limit is several μm.
It refers to the degree.

The electron-emitting portion 2 is constituted by a high-resistance crack formed in a part of the conductive film 3 and depends on the film thickness, film quality and material of the conductive film 3 and the energization forming method described later. However, the crack width is uniform and 50n
m or less. For the measurement of the crack width, the crack is observed over the entire length of the electron-emitting portion using an electron microscope, measurement points are determined at intervals of 1 μm along the electron-emitting portion, and the width of the crack is measured at each portion. In this specification, "the crack width is uniform" means that the measured values at 70% or more of all the measured points are within 20% of a certain central value. In addition, the term “crack width” for the entire electron emitting portion means the above-mentioned center value.

The inside of the electron emission section 2 has a size of several tens to several tens of n.
In some cases, conductive fine particles having a particle size in the range of m exist.
The conductive fine particles contain some or all of the elements of the material constituting the conductive film 3. When the electron-emitting portion 2 and the conductive film 3 in the vicinity of the electron-emitting portion 2 have undergone an activation step described later, a simple substance and a compound composed of some or all of the elements contained in the gas phase subjected to the activation step are used. May have. Specifically, it has carbon and / or a carbon compound or a metal and / or a metal compound. In addition, the position of the electron emission unit 2 is not limited to FIG.

Next, a vertical type surface conduction electron-emitting device will be described.

FIG. 2 is a schematic view showing an example of the configuration of a vertical surface conduction electron-emitting device applicable to the present invention. The same portions as those shown in FIG. The same reference numerals are used as in FIG. 21 is a step forming part. The substrate 1, the device electrodes 4 and 5, the conductive film 3, and the electron-emitting portion 2
It can be made of the same material as that of the above-mentioned flat surface conduction electron-emitting device. The step forming portion 21 can be made of an insulating material such as SiO ₂ formed by a vacuum deposition method, a printing method, a sputtering method, or the like. Step forming part 21
Has a thickness in the range of several hundred nm to several hundred μm corresponding to the element electrode interval L of the above-mentioned flat surface conduction electron-emitting device. This film thickness is set in consideration of the manufacturing method of the step forming portion and the voltage applied between the device electrodes, and is preferably in the range of several μm to several tens μm.

The conductive film 3 is stacked on the device electrodes 4 and 5 after the device electrodes 4 and 5 and the step forming portion 21 are formed. In FIG. 2, the electron emitting unit 2 includes a step forming unit 21.
However, the shape and position are not limited to the above depending on the forming conditions, forming conditions, and the like.

An example of the manufacturing method of the surface conduction electron-emitting device having the structure shown in FIG. 1 will be described below with reference to the manufacturing process diagram of FIG. In FIG. 3, the same parts as those shown in FIG. 1 are denoted by the same reference numerals as those shown in FIG.

1) After sufficiently cleaning the insulating substrate 1 using a detergent, pure water, an organic solvent or the like, depositing the element electrode material by vacuum evaporation, sputtering, or the like, the substrate is etched using, for example, a photolithography technique. Element electrodes 4 and 5 are formed on 1 (FIG. 3A).

2) On the substrate 1 provided with the device electrodes 4 and 5,
An organometallic solution is applied to form an organometallic film. As the organic metal solution, a solution of an organic compound containing the metal of the material of the conductive film 3 as a main element can be used. The organic metal film is heated and baked, and patterned by lift-off, etching, or the like to form a conductive film 3 made of a metal oxide (FIG. 3B). Here, the method of applying the organometallic solution has been described, but the method of forming the conductive film 3 is not limited to this, and a vacuum deposition method, a sputtering method, a chemical vapor deposition method, a dispersion coating method, A dipping method, a spinner method, or the like can also be used.

3) Subsequently, a forming step is performed. When electricity is supplied from a power source (not shown) between the device electrodes 4 and 5, a portion of the conductive film 3 where the structure is locally changed, such as destruction, deformation or alteration, is formed. The portion constitutes the electron emission section 2 (FIG. 3C).

A pulse voltage is used as a voltage applied to the element for the forming process. As a pulse shape, for example, a triangular wave pulse having a constant peak value as shown in FIG. 20A or a triangular wave pulse having a gradually increasing peak value as shown in FIG. 20B can be used.

In the case of the pulse having the shape shown in FIG. 20A, for example, the pulse width T ₁ is 1 μsec to 10 msec, and the pulse interval T ₂ is 1
About 0 μsec to 100 msec, and appropriately select the peak value,
Apply for a few seconds to tens of minutes. In the case of the pulse having the shape shown in FIG. 20B, T ₁ and T ₂ are the same as above, and are applied while gradually increasing the peak value.

The end of the energization forming process can be detected by applying a voltage pulse between the pulses that does not cause the destruction, deformation or alteration of the conductive film 3 and measuring the current flowing through the element. it can. For example, 0.
Measure the current flowing through the element by applying a voltage of about 1 V,
It is preferable to calculate the resistance value and terminate the energization forming when the resistance value exceeds 1 MΩ.

The energization forming process is performed in an atmosphere containing a reducing substance.

When the conductive film 3 is made of a metal oxide,
In addition to H ₂ , CO, etc., methane,
Ethane, ethylene, propylene, benzene, toluene,
Gases of organic substances such as methanol, ethanol and acetone are also effective. This is presumably because when the material constituting the conductive film changes from metal oxide to metal by reduction, aggregation occurs with the metal. On the other hand, when the conductive film 3 is made of a metal, CO or acetone or the like does not show the effect of promoting the aggregation because the aggregation due to reduction does not occur, but H ₂ promotes the aggregation even in this case. Show the effect.

When the energization forming process is performed in the above-described atmosphere, the required electric power can be reduced by several tens of% as compared with the case where the similar process is performed in a vacuum as in the related art. This is because in the conventional method, the temperature of the conductive film 3 rises due to Joule heat generated by the current flowing through the element, thereby causing local destruction, deformation or deterioration,
When the electron-forming process is performed in the above-described atmosphere while the electron-emitting portion 2 is formed, local destruction, deformation, or alteration of the conductive film is promoted by a substance that promotes aggregation of the conductive film, It is presumed that this is because the power required for processing can be reduced.

The preferable pressure of the reducing substance gas varies depending on conditions such as the type of gas, the material of the conductive film 3 and the waveform of the applied voltage pulse. If the pressure is relatively low,
When the forming process is performed by applying a voltage pulse whose pulse crest value gradually increases, the effect of reducing the power required for the process appears. On the other hand, when the pressure is high, by applying a voltage pulse having a constant pulse peak value, it is possible to obtain the effect of making the crack width uniform and preventing the generation of a leak current.

In the case where the material of the conductive film 3 is a metal oxide which is relatively easily reduced, when a plurality of elements are processed, even if the resistance values of the respective conductive films vary, this is not considered. The effect of suppressing the resulting variation in electron emission characteristics is expected. That is, when an electric current is applied to the conductive film made of a metal oxide in the above atmosphere, reduction occurs due to an increase in temperature due to heat generation, and the resistance value of the conductive film decreases. At this time, if the peak value of the voltage pulse applied to the element is kept constant, the current flowing through the conductive film increases,
The calorific value also increases. Even if the initial resistance value of the conductive film is different for each element, since the amount of heat generated when the electron emission portion is formed is considered to be substantially the same for all the elements, a pulse voltage under the same condition is applied. In this case, when the resistance value of the conductive film decreases to the same value, the formation of the electron emission portion occurs. For this reason, the electron-emitting portion is formed under almost the same conditions in any element, and the variation in the electron-emitting characteristics is suppressed.

As the pulse voltage for the energization forming, the waveform shown in FIG. 4A or 4B can be preferably used.

[0061] In such a energization forming is the peak value of the pulse voltage, for example 0.1V while step by step increasing voltage is applied, the conductive film 3 is pulse peak value to the voltage V _h to start the low-resistance or aggregation reaches after a certain period of time T _h, carried out by applying a pulse while maintaining tens minutes voltage V _h, for example, from a few seconds. Alternatively, when the value of V _h is calculated in advance sufficient accuracy, set from the beginning to the V _h the pulse height may be performed retention for a certain time.

[0062] In this way, by a predetermined time T _h held at a voltage V _h, is the conductive film material on a part of the conductive film 3 is gradually formed a region of the discontinuous film made of aggregated fine particles it can. During this time, the resistance value between the element electrodes 4 and 5 including the conductive film 3 goes toward high resistance, and the forming process ends when the resistance value has sufficiently reached high resistance. Further, when the resistance value during the retention time of T _h does not reach a sufficiently high resistance, further advances the high resistance by applying a pulse to increase the pulse width, a method of terminating the forming (FIG. 4
(A)) and a method of increasing the pulse peak value again to increase the resistance and ending the forming (FIG. 4 (b)).
There is a method (not shown) in which both of them are used together to increase the pulse width and further increase the pulse crest value. In this manner, the electron emitting portion 2 formed of a crack having a width of 50 nm or less can be formed in a part of the conductive film 3. This will be further described.

The method of gradually increasing the pulse peak value described in the specification of Japanese Patent Application No. 6-141670 is described as PdO.
When applied to a step of forming a device having a conductive film made of fine particles in a vacuum, the resistance value of the device is:
As the pulse crest value is increased, it changes as schematically shown in FIG. 21. When the pulse crest value reaches V _form , the forming process is completed. That is, by applying a pulse voltage between the element electrodes and flowing a current through the conductive film, heat is generated and the temperature of the conductive film increases. If the calorific value is large, a part of the conductive film is deformed and deteriorated at once, and the resistance value is increased. On the other hand, when the calorific value is not so large, the material of the conductive film gradually aggregates. When the material of the conductive film is a metal oxide that is relatively easily reduced like PdO, the reduction proceeds simultaneously.

In FIG. 21, after the pulse peak value exceeds V _s , the resistance value of the element once decreases and then starts to increase because the resistance decreases due to reduction and the current path is cut off due to aggregation. This may be due to competition with the effect of increasing resistance. When the conductive film is formed of a metal, the reduction in resistance is smaller than that of a metal oxide, but the same behavior is obtained. Although the cause of the decrease in resistance in this case is not clearly understood, it is speculated that the reason may be that the contact resistance between metal fine particles or metal crystal grains constituting the conductive film becomes small. In any case, it is considered that when the pulse crest value is _{equal to} or more than Vs, the material of the conductive film causes aggregation. The value of V _s itself depends on the pulse width and pulse interval of the applied pulse, the resistance and material of the conductive film, and the like.

That is, the voltage V _{h at} which the conductive film 3 starts lowering resistance or agglomeration is larger than V _s and V
_The voltage value is much smaller than _form .

In the pulse voltage waveform of the energization forming shown in FIG. 4, the pulse width T ₁ is, for example, 1 μsec to 10 m.
S, the pulse interval T ₂ are 100μ seconds to several seconds, the pulse width T ₁ of the pulse voltage after a predetermined time T _h is 10μ to 1 second,
V _h is appropriately set according to the material and form of the conductive film 3, T ₁ , T _2, etc., but the forming voltage V _form observed in the conventional forming process in which the voltage is applied while increasing the voltage monotonously is applied. That is, with respect to the voltage at which the element resistance rapidly increases, the resistance is set to 0. The voltage is set to be several% to several tens% lower. It is preferable pulse interval T ₂ are sufficiently long to pulse width _{T 1, T 2 / T 1} ≧ 5, preferably T ₂ / T ₁ ≧ ₁
0, more preferably T ₂ / T ₁ ≧ 100. The voltage waveform to be applied is not limited to the illustrated rectangular wave, and a desired waveform such as a triangular wave can be used. Suitable values for V _h is, T _1, the value of T ₂ are, of course, since the pulse waveform is also affected by such whether it is such as a rectangular wave, a triangular wave, it is set according to these conditions .

4) It is preferable to perform a process called an activation step on the device after the forming. The activation process is a process in which the device current _If and the emission current _Ie are significantly changed by this process.

The activation step can be performed, for example, by repeatedly applying a pulse to the element in an atmosphere containing a gas of an organic substance. This atmosphere can be formed by using an organic gas remaining in the atmosphere when the inside of the vacuum vessel is evacuated using, for example, an oil diffusion pump or a rotary pump, or is sufficiently evacuated once by an ion pump or the like. It can also be obtained by introducing a gas of an appropriate organic substance into a vacuum. The preferable gas pressure of the organic substance at this time varies depending on the above-described application form, the shape of the vacuum vessel, the type of the organic substance, and the like, and is accordingly set as appropriate. Suitable organic substances include alkanes, alkenes, aliphatic hydrocarbons of alkynes, aromatic hydrocarbons,
Examples thereof include organic acids such as alcohols, aldehydes, ketones, amines, phenol, carboxylic acid, and sulfonic acid. Specifically, methane, ethane, and propane are represented by C _n H _{2n + 2.} Saturated hydrocarbons, ethylene,
Unsaturated hydrocarbons represented by a composition formula such as C _n H _2n such as propylene, benzene, toluene, methanol, ethanol, formaldehyde, acetaldehyde, acetone,
Methyl ethyl ketone, methylamine, ethylamine, phenol, formic acid, acetic acid, propionic acid and the like can be used.
By this treatment, carbon or a carbon compound is deposited on the device from the organic substance existing in the atmosphere, and the device current _If and the emission current _Ie change remarkably.

The same effect can be obtained by performing the activation treatment in an atmosphere containing a metal compound having an appropriate vapor pressure to deposit the metal on the element. Metal compounds include fluoride, chloride, bromide,
Metal halides such as iodides, methylated compounds, ethylated compounds, alkyl metals such as benzylated compounds, acetylacetonates, dipivaloyl methanates, metal β-diketonates such as hexafluoroacetylacetonate, allyl complexes, cycloalkyl Examples thereof include metal enyl complexes such as pentadienyl complexes, arene complexes such as benzene complexes, metal carbonyls, metal alkoxides and the like, and composite compounds thereof. In the present invention, NbF ₅ , NbCl ₅ , Nb (C
_{5 H 5) (CO) 4} , Nb (C 5 H 5) 2 Cl 2, OsF 4, O
s (C ₃ H ₇ O ₂ ) ₃ , Os (CO) ₅ , Os ₃ (CO) ₁₂ ,
_{Os (C 5 H 5) 2} , ReF 5, ReCl 5, Re (CO)
_{10, ReCl (CO) 5,} Re (CH 3) (CO) 5, R
_{e (C 5 H 5) (} CO) 3, Ta (C 5 H 5) (CO) 4, T
a (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. In this case, depending on the conditions, a substance such as carbon may be contained in the film in addition to the metal.

The termination of the activation step can be appropriately determined while measuring the device current _If and the emission current _Ie .
The pulse width, pulse interval, pulse crest value, and the like are set as appropriate.

The carbon and carbon compound include, for example, graphite (so-called HOPG, PG, GC), and HOPG has an almost complete graphite crystal structure, PG
Are those with crystal grains of about 20 nm and a slightly disordered crystal structure,
GC refers to a crystal having a crystal grain of about 2 nm and further disorder in the crystal structure. ), Amorphous carbon (refers to amorphous carbon and a mixture of amorphous carbon and the above-mentioned graphite microcrystals), hydrocarbon (C
_m H _n compound represented by, or containing N, O, a compound having other elements such as Cl In addition to this. ), And the film thickness is preferably in the range of 50 nm or less,
More preferably, the range is not more than m.

5) The electron-emitting device obtained through the above steps is preferably subjected to a stabilization step. This step is a step of exhausting the organic substance in the vacuum container. The pressure inside the vacuum vessel needs to be as low as possible.
0 ^-5 Pa or less, and more preferably 1.3 × 10 ^-6 Pa
The following are particularly preferred. It is preferable to use a vacuum exhaust device that does not use oil so that the oil generated from the device does not affect the characteristics of the element. Specifically, a vacuum exhaust device such as a sorption pump or an ion pump can be used. Further, when evacuating the inside of the vacuum vessel, it is preferable to heat the entire vacuum vessel to facilitate evacuating the organic substance molecules adsorbed on the inner wall of the vacuum vessel and the electron-emitting device.

The atmosphere during driving after the stabilization step is preferably the same as the atmosphere at the end of the stabilization treatment, but is not limited to this, and organic substances or metal compounds are sufficiently removed. Therefore, even if the pressure itself increases somewhat, it is possible to maintain sufficiently stable characteristics.

By employing such a vacuum atmosphere, the deposition of new carbon, carbon compound or metal can be suppressed, and as a result, the device current _If and the emission current _Ie are stabilized.

The basic characteristics of the electron-emitting device obtained through the above-described steps will be described with reference to FIGS.

FIG. 5 is a schematic diagram showing an example of a vacuum processing apparatus. This vacuum processing apparatus also has a function as a measurement and evaluation apparatus. Also in FIG. 5, the same parts as those shown in FIG. 1 are denoted by the same reference numerals as those shown in FIG.

In FIG. 5, reference numeral 55 denotes a vacuum vessel;
Reference numeral 6 denotes an exhaust pump. Electron emitting element in the vacuum vessel 55
The child is arranged. Reference numeral 51 denotes a device electrode for the electron-emitting device.
Pressure V _fA power supply for applying a voltage between the device electrodes 4 and 5
Current I flowing through the conductive film 3_fFor measuring
A flow meter 54 indicates an emission current emitted from the electron emission portion 2 of the device.
Style I_eAnode electrode for trapping, 53 is an anode
A high-voltage power supply for applying a voltage to the electrode 54;
Emission current I emitted from the emission section 2_eFor measuring
It is an ammeter. As an example, the voltage of the anode electrode 54 is
The anode electrode 54 is connected to the electron
The measurement was performed with the distance H to the emitting element in the range of 2 to 8 mm.
I can.

The vacuum vessel 55 is provided with equipment necessary for measurement in a vacuum atmosphere, such as a vacuum gauge (not shown).
The measurement and evaluation can be performed in a desired vacuum atmosphere.

The exhaust pump 56 is composed of a normal high vacuum system such as a turbo pump and a rotary pump and an ultra high vacuum system such as an ion pump.
Switch and use as appropriate. The entire vacuum processing apparatus provided with the electron-emitting device substrate shown here can be heated by a heater (not shown). Therefore, by using this vacuum processing apparatus, the steps after the energization forming described above can also be performed.

FIG. 6 is a diagram schematically showing the relationship between the emission current I _e and the device current _If measured using the vacuum processing apparatus shown in FIG. 5, and the device voltage _Vf . In FIG. 6, since the emission current _Ie is significantly smaller than the device current _If , it is shown in arbitrary units. The vertical and horizontal axes are linear scales.

As is clear from FIG. 6, the surface conduction electron-emitting device applicable to the present invention has the following three characteristic characteristics with respect to the emission current _Ie .

That is, first, the present element operates at a certain voltage (threshold voltage).
Called pressure; V in FIG._th) When the above element voltage is applied
Sudden emission current I_eIncreases while the threshold voltage V_thBelow
Is the emission current I_eIs hardly detected. That is, the emission current
I_eThreshold voltage V for _thIs a nonlinear element with
is there.

Second, since the emission current _Ie depends monotonically on the device voltage _Vf , the emission current _Ie can be controlled by the device voltage _Vf .

Third, the anode electrode 54 (see FIG. 5)
The trapped emission charge is the device voltage V _fTime to apply
Dependent. That is, the electric charge captured by the anode electrode 54
The quantity is the element voltage V_fCan be controlled by the application time.

As understood from the above description, the surface conduction electron-emitting device applicable to the present invention can easily control the electron emission characteristics according to the input signal. By utilizing this property, it is possible to apply to various fields such as an electron source and an image forming apparatus having a plurality of electron-emitting devices.

[0086] In Figure 6, the device current I _f is monotonously increased with respect to the device voltage V _f (hereinafter referred to as "MI characteristic".) Has shown an example, device current I _f is to the device voltage V _f In some cases, the voltage control type negative resistance characteristic (hereinafter, referred to as “VCNR characteristic”) may be exhibited (not shown). These properties can be controlled by controlling the steps described above.

By arranging a plurality of the above-mentioned surface conduction electron-emitting devices on a substrate, an electron source according to the present invention can be constructed, and an image forming apparatus according to the present invention can be constructed using such an electron source. Hereinafter, an electron source and an image forming apparatus according to the present invention will be described in detail.

Various arrangements of the electron-emitting devices can be adopted. As an example, each of a large number of electron-emitting devices arranged in parallel is connected at both ends, a large number of rows of electron-emitting devices are arranged (referred to as a row direction), and a direction perpendicular to the wiring (referred to as a column direction). There is a ladder-type arrangement in which electrons from the electron-emitting devices are controlled and driven by control electrodes (also referred to as grids) disposed above the electron-emitting devices. Separately, a plurality of electron-emitting devices are arranged in a matrix in the X and Y directions, and one of the electrodes of the plurality of electron-emitting devices arranged in the same row is commonly connected to a wiring in the X direction. One example is one in which the other of the electrodes of a plurality of electron-emitting devices arranged in the same column is commonly connected to a wiring in the Y direction. 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 applicable to the present invention has three characteristics as described above. That is,
When the electron emission from the surface conduction electron-emitting device is equal to or higher than the threshold voltage, it can be controlled by the peak value and the width of the pulse voltage applied between the opposing device electrodes. On the other hand, below the threshold voltage, almost no emission occurs. According to this characteristic, even when a large number of electron-emitting devices are arranged, if a pulse-like voltage is appropriately applied to each of the devices, a surface conduction electron-emitting device is selected according to an input signal, and the amount of electron emission is determined. Can be controlled.

Hereinafter, an electron source substrate obtained by arranging a plurality of electron-emitting devices based on this principle will be described with reference to FIG. In FIG. 7, reference numeral 71 denotes an electron source substrate, 72 denotes an X-direction wiring, and 73 denotes a Y-direction wiring. 74 is a surface conduction electron-emitting device, and 75 is a connection. Incidentally, the surface conduction electron-emitting device 74 may be either the above-mentioned flat type or vertical type.

The m X-direction wirings 72 are Dx1, Dx
2,..., Dxm, and can be formed of a conductive metal or the like formed using a vacuum deposition method, a printing method, a sputtering method, or the like. The material, thickness and width of the wiring are appropriately designed.
The Y-direction wiring 73 is formed of n of Dy1, Dy2,.
It is formed in the same manner as the X-direction wiring 72. These m X-direction wires 72 and n Y-direction wires 7
3, an interlayer insulating layer (not shown) is provided.
Both are electrically separated (m and n are both positive integers).

The interlayer insulating layer (not shown) is made of SiO ₂ or the like formed by using a vacuum 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 71 on which the X-directional wiring 72 is formed. The material and the production method are appropriately set. The X-direction wiring 72 and the Y-direction wiring 73 are respectively drawn out as external terminals.

A pair of device electrodes (not shown) constituting the surface conduction electron-emitting device 74 are connected to m X-direction wires 72 and n Y-direction wires 73 by a connection 75 made of a conductive metal or the like. It is electrically connected.

The material forming the wiring 72 and the wiring 73, the material forming the connection 75, and the material forming the pair of device 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-described materials for the device electrodes. When the material forming the element electrode is the same as the wiring material, the wiring connected to the element electrode can also be called an element electrode.

The X-direction wiring 72 is connected to a scanning signal applying means (not shown) for applying a scanning signal for selecting a row of the surface conduction electron-emitting devices 74 arranged in the X direction.
On the other hand, a modulation signal generating means (not shown) for modulating each column of the surface conduction electron-emitting devices 74 arranged in the Y direction according to an input signal is connected to the Y-direction wiring 73. The driving voltage applied to each electron-emitting device is supplied as a difference voltage between a scanning signal and a modulation signal applied to the device.

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

An image forming apparatus constructed using such an electron source having a simple matrix arrangement will be described with reference to FIGS. 8, 9 and 10. FIG. FIG. 8 is a schematic view showing an example of a display panel of the image forming apparatus, and FIG. 9 is a schematic view of a fluorescent film used in the image forming apparatus of FIG. FIG.
FIG. 2 is a block diagram showing an example of a drive circuit for performing display according to an NTSC television signal.

In FIG. 8, reference numeral 71 denotes an electron source substrate on which a plurality of electron-emitting devices are arranged; 81, a rear plate on which the electron source substrate 71 is fixed; 86, a fluorescent film 84 on the inner surface of a glass substrate 83;
And a face plate on which a metal back 85 and the like are formed. Reference numeral 82 denotes a support frame. For the support frame 82, the rear plate 81 and the face plate 86 are made of frit glass or the like.
The envelope 88 is formed by baking for 10 minutes or more in a temperature range of 0 ° C. and sealing.

Reference numeral 74 denotes an electron-emitting device as shown in FIG. Reference numerals 72 and 73 denote an X-direction wiring and a Y-direction wiring connected to a pair of device electrodes of the surface conduction electron-emitting device.

The envelope 88 is composed of the face plate 86, the support frame 82, and the rear plate 81 as described above. Since the rear plate 81 is provided mainly for the purpose of reinforcing the strength of the substrate 71, if the substrate 71 itself has sufficient strength, the separate rear plate 81 can be unnecessary. That is, the support frame 82 is directly sealed to the substrate 71, and the envelope 8 is formed by the face plate 86, the support frame 82 and the substrate 71.
8 may be configured. On the other hand, by installing a support (not shown) called a spacer between the face plate 86 and the rear plate 81, the envelope 88 having sufficient strength against atmospheric pressure can be configured.

FIG. 9 is a schematic diagram showing a fluorescent film. The fluorescent film 84 can be composed of only a phosphor in the case of monochrome. In the case of a color fluorescent film, a black conductive material 91 called a black stripe (FIG. 9A) or a black matrix (FIG. 9B) or the like and a fluorescent material 92 may be used depending on the arrangement of the fluorescent materials. it can. The purpose of providing a black stripe and black matrix is
In the case of color display, the color separation between the phosphors 92 of the necessary three primary color phosphors is made black so that color mixing and the like become inconspicuous, and the reduction in contrast due to reflection of external light on the phosphor film 84 is suppressed. It is in. Black conductive material 91
As the material of, other than a commonly used material containing graphite as a main component, a material having conductivity and low light transmission and reflection can be used.

The method of applying the phosphor on the glass substrate 83 can employ a precipitation method or a printing method irrespective of monochrome or color. Usually, a metal back 85 is provided on the inner surface side of the fluorescent film 84. The purpose of providing a metal back is
The light emitted from the phosphor toward the inner surface is converted into a face plate 8.
Improving the brightness by specular reflection on the 6 side,
The purpose is to function as an electrode for applying an electron beam acceleration voltage, and to protect the phosphor from damage due to collision of negative ions generated in the envelope. The metal back can be manufactured by performing a smoothing process (usually called “filming”) on the inner surface of the fluorescent film after manufacturing the fluorescent film, and then depositing Al using vacuum evaporation or the like.

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

When performing the above-described sealing, in the case of color, it is necessary to make the phosphors of each color correspond to the electron-emitting devices, and sufficient alignment is indispensable.

After the sealing of the envelope 88, the energization forming of the electron-emitting device is performed. After the inside of the envelope is sufficiently evacuated by the exhaust device, a desired gas is introduced into the envelope as necessary, and one of the element rows of the electron source is selected, and the electron-emitting device belonging to this is selected. At the same time. The pulse width T ₁ , pulse interval T ₂ , and peak value of the pulse voltage are the same as those used in the forming process of a single element.

In the method of manufacturing an electron source according to the present invention, when a pulse voltage is sequentially applied to each element row to perform a forming process, an element row selecting means is provided between the pulse generating means and the electron source to provide one to one. It is preferable to perform the forming process on a plurality of element rows simultaneously by changing the element row to be selected every several pulses. At this time, it is preferable that the pulse interval T ₂ is set to be considerably longer than the pulse width T ₁ so as to satisfy T ₂ ≧ 5 × T _1. Can be greatly reduced.

In the manufacturing method of the present invention, the entire electron source may be divided into several blocks each including a plurality of element rows, and forming processing may be performed for each block.
The selection is appropriately made according to conditions such as the size of the electron source and the shape of the pulse used for processing.

When the forming process is performed in an atmosphere containing a gas that promotes coagulation such as H ₂ , the material of the conductive film is a metal oxide that is relatively easily reduced, The method shows a more pronounced effect. That is, in such an atmosphere, the reduction of the metal oxide constituting the conductive film may proceed gradually without generating heat by passing a current. At this time,
If the procedure of performing the processing of the next element row after finishing the forming processing of one element row is taken, the resistance value of the conductive film of the electron-emitting device belonging to the element row to be processed later becomes equal to that of the previous element row. , And as a result, the electron emission characteristics may differ depending on the element row. However, according to the method of switching and processing the element row to be selected every one to several pulses as described above, all the element rows are processed almost simultaneously, so that such a problem can be avoided.

[0109] Within the envelope 88, similar to the aforementioned stabilization step, while being heated appropriately, ion pump, by an exhaust device not using oil, such as a sorption pump evacuated through an exhaust pipe (not shown), 10 ^- After the atmosphere of a vacuum degree of about ⁵ Pa is sufficiently low for the organic substance, sealing is performed. In order to maintain a vacuum degree after the envelope 88 is sealed, a getter process may be performed. This is because a getter (not shown) disposed at a predetermined position in the envelope 88 is heated by heating using resistance heating, high-frequency heating, or the like immediately before or after the envelope 88 is sealed. This is a process for forming a deposited film. The getter is usually composed mainly of Ba or the like, and for example, 1.3 × 10 ⁻³ due to the adsorption action of the deposited film.
The pressure is maintained at Pa or 1.3 × 10 ⁻⁵ Pa. Here, steps after the forming process of the surface conduction electron-emitting device can be appropriately set.

Next, an example of the configuration of a drive circuit for performing television display based on NTSC television signals on a display panel configured using electron sources in a simple matrix arrangement will be described with reference to FIG. . In FIG.
101 is an image display panel, 102 is a scanning circuit, 103 is a control circuit, 104 is a shift register, 105 is a line memory, 106 is a synchronization signal separation circuit, 107 is a modulation signal generator, and Vx and Va are DC voltage sources.

The display panel 101 has terminals Dx1 to Dx
m, terminals Dy1 to Dyn, and a high voltage terminal 87 are connected to an external electric circuit. Terminals Dx1 to Dxm sequentially drive electron sources provided in the display panel 101, that is, a group of surface conduction electron-emitting devices arranged in a matrix of m rows and n columns in a matrix (row by row). A scanning signal for performing the scanning is applied. The terminals Dy1 to Dyn include
A modulation signal for controlling an output electron beam of each element of one row of surface conduction electron-emitting devices selected by the scanning signal is applied. The high-voltage terminal 87 is supplied with a DC voltage of, for example, 10 kV from a DC voltage source Va. The DC voltage is applied to the electron beam emitted from the surface conduction electron-emitting device.
It is an accelerating voltage for applying sufficient energy to excite the phosphor.

Next, the scanning circuit 102 will be described. The circuit includes m switching elements (S1 to S
m is schematically shown). Each switching element is connected to the output voltage of the DC voltage source Vx or 0
[V] (ground level) is selected, and is electrically connected to the terminals Dx1 to Dxm of the display panel 101. Each of the switching elements S1 to Sm operates based on a control signal Tscan output from the control circuit 103, and can be configured by combining switching elements such as FETs, for example.

In the case of the present embodiment, the DC voltage source Vx determines that the driving voltage applied to the non-scanned element is equal to or lower than the electron emission threshold voltage based on the characteristics (electron emission threshold voltage) of the surface conduction electron-emitting element. It is set to output such a constant voltage.

The control circuit 103 has a function of matching the operation of each unit so that appropriate display is performed based on an image signal input from the outside. The control circuit 103 controls the synchronization signal Tsync sent from the synchronization signal separation circuit 106.
, Tscan, Tsft and T
mry control signals are generated.

The synchronizing signal separating circuit 106 is a circuit for separating a synchronizing signal component and a luminance signal component from an NTSC television signal input from the outside, and uses a general frequency separating (filter) circuit or the like. Can be configured. The synchronizing signal separated by the synchronizing signal separating circuit 106 includes a vertical synchronizing signal and a horizontal synchronizing signal, but is shown here as a Tsync signal for convenience of explanation. The luminance signal component of the image separated from the television signal is represented as a DATA signal for convenience. This DATA signal is output to the shift register 10
4 is input.

The shift register 104 is for serially / parallel converting the DATA signal input serially in time series for each line of an image, and is based on a control signal Tsft sent from the control circuit 103. (In other words, the control signal Tsft may be rephrased as a shift clock of the shift register 104). Data for one line of serial / parallel converted image (equivalent to drive data for n electron-emitting devices)
Are output from the shift register 104 as n parallel signals Id1 to Idn.

The line memory 105 is a storage device for storing data for one line of an image for a necessary time only, and stores the contents of Id1 to Idn as appropriate according to a control signal Tmry sent from the control circuit 103. The stored contents are output as Id′1 to Id′n and input to the modulation signal generator 107.

Modulation signal generator 107 outputs image data I
a signal source for appropriately driving and modulating each of the surface conduction electron-emitting devices according to each of d′ 1 to Id′n;
The output signal is applied to the surface conduction electron-emitting device in the display panel 101 through the terminals Dy1 to Dyn.

As described above, the electrons applicable to the present invention
The emission element has an emission current I_eHas the following basic characteristics
ing. That is, a clear threshold voltage V is required for electron emission._thThere
And V _thElectron emission occurs only when the above voltage is applied
You. For voltages above the electron emission threshold, apply to the device
The emission current changes according to the change in the voltage. This thing
When applying a pulsed voltage to this element,
Electron emission occurs even when a voltage below the electron emission threshold voltage is applied.
However, if a voltage higher than the electron emission threshold voltage is applied,
Outputs an electron beam. At this time, the pulse peak value V
m, the intensity of the output electron beam is controlled.
It is possible to control. Also changes the pulse width Pw
The total amount of charge of the output electron beam
Can be controlled.

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 implementing the voltage modulation method, the modulation signal generator 107 generates a voltage pulse of a fixed length, and a voltage modulation circuit capable of appropriately modulating the peak value of the voltage pulse according to input data. Can be used. When implementing the pulse width modulation method, the modulation signal generator 107 generates a voltage pulse having a constant peak value and modulates the width of the voltage pulse appropriately according to input data. A circuit can be used.

The shift register 104 and the line memory 10
5 can be a digital signal type or 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 synchronization signal separation circuit 106 into a digital signal. For this purpose, an A / D converter is provided at the output of the synchronization signal separation circuit 106. Just do it. In this connection, the circuit used for the modulation signal generator 107 is slightly different depending on whether the output signal of the line memory 105 is a digital signal or an analog signal. That is, in the case of the voltage modulation method using a digital signal, the modulation signal generator 107 includes:
For example, a D / A conversion circuit is used, and an amplification circuit and the like are added as necessary. In the case of the pulse width modulation method, the modulation signal generator 107 includes, for example, a high-speed oscillator, 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. (Comparator) is used. If necessary, an amplifier for voltage-amplifying the pulse width modulated signal output from the comparator to the drive voltage of the surface conduction electron-emitting device can be added.

In the case of the voltage modulation method using an analog signal, an amplification circuit using, for example, an operational amplifier or the like can be used as the modulation signal generator 107, and a level shift circuit or the like can be added as necessary. In the case of the pulse width modulation method, for example, a voltage-controlled oscillation circuit (VCO) can be employed, and an amplifier for amplifying the voltage up to the driving voltage of the surface conduction electron-emitting device can be added as necessary.

In the image forming apparatus to which the present invention can be applied, which has such a configuration, by applying a voltage to each of the electron-emitting devices via the terminals Dx1 to Dxm and Dy1 to Dyn outside the container, the electron-emitting devices can emit electrons. Occurs. A high voltage is applied to the metal back 85 or a transparent electrode (not shown) via the high voltage terminal 87 to accelerate the electron beam. The accelerated electrons collide with the fluorescent film 84 and emit light to form an image.

The configuration of the image forming apparatus described here is an example of an image forming apparatus to which the present invention can be applied, and various modifications can be made based on the technical idea of the present invention. The input signal has been described in the NTSC system. However, the input signal is not limited to this. In addition to the PAL and SECAM systems,
A TV signal composed of more scanning lines than these (for example,
A high-definition TV system such as the MUSE system can also be adopted.

Next, the electron source and the image forming apparatus having the above-mentioned ladder-type arrangement will be described with reference to FIGS.

FIG. 11 is a schematic view showing an example of a ladder-type electron source. In FIG. 11, reference numeral 110 denotes an electron source substrate, and 111 denotes an electron-emitting device. Reference numeral 112 denotes common wirings D1 to D10 for connecting the electron-emitting devices 111, and these are drawn out as external terminals. A plurality of electron-emitting devices 111 are arranged on the substrate 110 in parallel in the X direction (this is called an element row). A plurality of the element rows are arranged to constitute an electron source. By applying a drive voltage between the common wires of each element row, each element row can be driven independently. That is, a voltage equal to or higher than the electron emission threshold is applied to an element row in which an electron beam is to be emitted, and a voltage equal to or lower than the electron emission threshold is applied to an element row in which an electron beam is not desired to be emitted. Common wirings D2 to D9 located between the element rows are, for example, D2 and D3, D4 and D5,
D6 and D7 and D8 and D9 may be formed as one and the same wiring.

FIG. 12 is a schematic diagram showing an example of a panel structure in an image forming apparatus having a ladder-type electron source. Reference numeral 120 denotes a grid electrode, 121 denotes an opening through which electrons pass, D1 to Dm denote external terminals, and G1 to Gn denote external terminals connected to the grid electrode 120. 1
Reference numeral 10 denotes an electron source substrate in which the common wiring between the element rows is the same wiring. In FIG. 12, the same portions as those shown in FIGS. 8 and 11 are denoted by the same reference numerals as those shown in these drawings. A major difference between the image forming apparatus shown here and the image forming apparatus having the simple matrix arrangement shown in FIG. 8 is whether or not the grid electrode 120 is provided between the electron source substrate 110 and the face plate 86.

In FIG. 12, a grid electrode 120 is provided between the substrate 110 and the face plate 86. The grid electrode 120 is for modulating the electron beam emitted from the surface conduction electron-emitting device 111, and allows the electron beam to pass through a stripe-shaped electrode provided orthogonal to the ladder-type element row. Therefore, one circular opening 121 is provided for each element. The shapes and arrangement positions of the grid electrodes are not limited to those shown in FIG. For example, a large number of passage openings may be provided in a mesh shape as openings, and a grid electrode may be provided around or near the surface conduction electron-emitting device.

The external terminals D1 to Dm and the external terminals G1 to Gn are electrically connected to a control circuit (not shown).

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

The image forming apparatus to which the present invention described above can be applied is not only a display device for a television broadcast, a display device such as a video conference system or a computer, but also an optical printer including a photosensitive drum. It can also be used as an image forming apparatus or the like.

[0133]

The present invention will be described below with reference to examples. It should be noted that the present invention is not limited to these embodiments, but includes those in which the replacement of each element or the design change is made within a range in which the object of the present invention is achieved.

[Embodiment 1] The present embodiment relates to a method of manufacturing an electron source in which a large number of surface conduction electron-emitting devices are arranged on a substrate, and these electron-emitting devices are arranged in a matrix.

FIG. 13 is a plan view showing a part of the electron source of this embodiment.
Shown in FIG. 14 is a sectional view taken along the line AA ′ in the figure.
13 and 14 indicate the same members. Here, 71 is a substrate, 72 is an X-direction wiring (also referred to as a lower wiring), 73 is a Y-direction wiring (also referred to as an upper wiring), 3 is a conductive film, 4 and 5 are element electrodes, 131 is an interlayer insulating layer, 132 Is a contact hole for electrical connection between the element electrode 4 and the lower wiring 72.

First, a method of manufacturing an electron source according to this embodiment will be specifically described with reference to FIGS. Steps -a to h described below correspond to FIG.
5 (a) to 5 (d) and FIGS. 16 (e) to 16 (h).

Step-a A 5 nm-thick Cr film and a 600 nm-thick Au film were formed by vacuum evaporation on a substrate 71 having a 0.5 μm-thick silicon oxide film formed on a cleaned blue plate glass by a sputtering method. After sequentially laminating, a photoresist (AZ1370; manufactured by Hoechst) was spin-coated with a spinner and baked.
The photomask image was exposed and developed to form a resist pattern for the lower wiring 72, and the Au / Cr deposited film was wet-etched to form the lower wiring 72 having a desired shape.

Step-b Next, an interlayer insulating layer 131 made of a silicon oxide film having a thickness of 1.0 μm was deposited by RF sputtering.

Step-c The contact hole 1 was formed in the silicon oxide film deposited in the step b.
Making a photoresist pattern to form 32;
Using this as a mask, the interlayer insulating layer 131 was etched to form a contact hole 132. Etching is CF
(Reactive Ion) using methane ₄ and H ₂ gas
Etching) method.

Step-d After that, a pattern to be the element electrodes 4 and 5 and the gap L between the element electrodes was formed by photoresist, and 5 nm thick Ti and 50 nm thick Ni were sequentially deposited by vacuum evaporation. Thereafter, the photoresist pattern was dissolved with an organic solvent, and the Ni / Ti deposited film was lifted off to form device electrodes 4 and 5 having a device electrode interval L of 10 μm and a device electrode width W1 of 300 μm.

Step-e After forming a photoresist pattern of the upper wiring 73 on the device electrodes 4 and 5, Ti having a thickness of 5 nm and a thickness of 500 nm
Were sequentially deposited by vacuum evaporation, and unnecessary portions were removed by lift-off to form an upper wiring 73 having a desired shape.

Step-f A 100 nm-thick Cr film 133 is deposited and patterned by vacuum evaporation using a mask having an opening L in the vicinity of the gap L between the device electrodes and an organic Pd solution (ccp-4230; Okuno). (Manufactured by Pharmaceutical Co., Ltd.) was applied by a spinner and heated and baked at 300 ° C. for 12 minutes in the air to form a conductive film 134 composed of fine particles of PdO.

Step-g The Cr film 133 is etched with an acid etchant,
Unnecessary portions of the conductive film 134 were removed by lift-off to form the conductive film 3 having a desired pattern shape. The thickness of the conductive film 3 is 7 nm, and the resistance value Rs is 2.
It was 1 × 10 ⁴ Ω / □.

Step-h A resist was applied to the entire surface, developed after exposure using a mask, and the resist was removed only in the contact hole 132 portion. Thereafter, Ti with a thickness of 5 nm and Au with a thickness of 500 nm are sequentially deposited by vacuum evaporation, and unnecessary portions are removed by lift-off, whereby contact holes 132 are formed.
Embedded.

Through the above steps, the insulating substrate 71 is
The lower wiring 72, the interlayer insulating layer 131, the upper wiring 73, the element electrodes 4 and 5, the conductive film 3, and the like are formed.
An unformed electron source substrate matrix-wired with the lower wiring 72 and the upper wiring 73 was obtained.

Next, an image forming apparatus was manufactured by using the unformed electron source substrate manufactured as described above.
The manufacturing procedure will be described below with reference to FIGS.

First, the unformed electron source substrate 7
1 is fixed on the rear plate 81, and 5 m
A face plate 86 (formed by forming a fluorescent film 84 as an image forming member and a metal back 85 on the inner surface of a glass substrate 83) is disposed above the glass substrate 83 via a support frame 82. Then, frit glass was applied to the joint between the support frame 82 and the rear plate 81, and baked at 400 ° C. for 10 minutes in the air to seal. The fixing of the substrate 71 to the rear plate 81 was also performed with frit glass.

The fluorescent film 84 serving as an image forming member
Is a stripe shape (FIG. 9) to realize color.
(A)) and the black stripe 9
1 was formed, and the phosphor 92 of each color was applied to the gap by a slurry method to form a phosphor film 84. As a material of the black stripe 91, a commonly used material mainly composed of graphite was used.

Further, a metal back 85 was provided on the inner surface side of the fluorescent film 84. The metal back 85 is manufactured by performing a smoothing process (usually called filming) on the inner surface of the fluorescent film 84 after the fluorescent film 84 is manufactured, and then performing vacuum deposition of Al.

At the time of performing the above-mentioned sealing, in the case of color, sufficient alignment was performed because each color phosphor 92 and each surface conduction electron-emitting device 74 had to correspond.

The inside of the vacuum container (enclosure 88) formed as described above is evacuated by an exhaust device through an exhaust pipe (not shown), and the pressure in the vacuum container is set to 1.3 × 10 ⁻³ Pa. After the following, a mixed gas of N ₂ 98% -H ₂ 2 was introduced into the vacuum vessel, and the pressure was adjusted to 5 × 10 ⁻² Pa.

FIG. 19 schematically shows wiring for applying a pulse voltage to each electron-emitting device for the forming process. The Y-direction wiring 73 is connected in common by connecting the external terminals Dy1 to Dyn to the common electrode 1401,
It is connected to the ground side terminal of pulse generator 1402. The X-direction wiring 72 is connected to the control switching circuit 1403 via the external terminals Dx1 to Dxm (the case where m = 20 and n = 60 is shown in the figure). The control switching circuit 1403 connects each terminal to either the pulse generator 1402 or the ground.
The figure schematically shows the function.

The forming process is performed by the switching circuit 1
By 403, one element row in the X direction is selected, and every time one pulse is applied, the selected element row is switched, and all element rows are processed simultaneously.

The waveform of the applied pulse voltage is shown in FIG.
This is a triangular wave pulse whose peak value gradually increases as shown in FIG. The pulse width T ₁ was 1 ms, and the pulse interval T ₂ was 10 ms. Further, a rectangular wave pulse having a peak value of 0.1 V was inserted between the above-mentioned pulses, and the resistance value of the element was measured.

Subsequently, an activation process was performed. At this time, the pressure in the vacuum vessel was 2.7 × 10 ⁻³ Pa. The applied pulse was a triangular wave pulse having a peak value of 14 V and a pulse width of 30 μs, and was applied to each row in the X direction as in the above-described forming.

After the activation, the vacuum vessel was evacuated while being heated. When the pressure in the vacuum vessel became 1.3 × 10 ⁻⁴ Pa or less, an exhaust pipe (not shown) was heated with a gas burner. The vacuum vessel was sealed by welding, and a getter process was performed by high-frequency heating to keep the pressure inside the vacuum vessel low.

In the image forming apparatus manufactured as described above, each electron-emitting device sequentially emits electrons by simple matrix driving, and the value of _Ie is measured for each device.
When the variation of the value of _Ie for each element was determined, the variation width was 5%.

[Comparative Example 1] In Example 1, when performing the forming process, the inside of the vacuum vessel (envelope 88) was evacuated by an exhaust device through an exhaust pipe (not shown). While the pressure was below _{^{1.3 × 10 -3 Pa, N 2}} 9
An image forming apparatus was manufactured in the same manner as in Example 1, except that a mixed gas of 8% -H2 ₂ % was not introduced into the vacuum vessel.

In the image forming apparatus manufactured as described above, each electron-emitting device sequentially emits electrons by simple matrix driving, and the value of _Ie is measured for each device.
When the variation of the value of _Ie for each element was determined, the variation width was 15%, which was larger than that in Example 1.

In the first embodiment, the forming process is performed in an atmosphere containing a substance having a coagulation promoting action, so that the current required for the forming process can be reduced, and the voltage drop due to the resistance of the wiring can be reduced. It is speculated that the variation in the effective voltage applied to each element during forming is reduced, and that the formation of the electron-emitting portion is performed under relatively uniform conditions.

[Embodiment 2 and Comparative Examples 2 to 4] This embodiment relates to an electron source and an image forming apparatus in which a large number of surface conduction electron-emitting devices are arranged on a substrate and arranged in a matrix, similarly to Embodiment 1. . The number of arranged elements is 20 rows and 60 columns including the three primary colors.

First, the manufacturing process of the electron source of this embodiment will be described.

In this example, the same steps were performed up to the steps -a to h and sealing in Example 1. However, the element electrode interval L is 3 μm, the element electrode width W ₁ is 200 μm, the conductive film 3 is a Pt thin film formed by a sputtering method, the thickness is 1.5 nm, and the resistance is Rs = 5 × 10 ⁴ Ω. / □. The C used for patterning the conductive film 3
The thickness of the r mask was 50 nm.

[0164] Eight image forming apparatuses, which have been completed up to the sealing step, are subjected to the following four methods (Example 2 and Comparative Example 2).
According to 4), two forming processes were performed. In addition, one of the forming processes performed by each method was used for observing the electron-emitting portion after the forming process by an electron microscope. During the forming process,
As shown in FIG. 19, the Y-direction wiring 73 is connected to an external terminal Dy1.
To Dy60 are connected in common by connecting them to a common electrode 1401 and are connected to a ground terminal of the pulse generator 1402. The X-direction wiring 72 has external terminals Dx1 to Dx1.
It is connected to the control switching circuit 1403 via Dx20. The switching circuit connects each terminal to one of the pulse generator 1402 and the ground.

(Example 2): An exhaust pipe (not
Exhausted by the exhaust device through the
0^-FourAfter lowering to Pa or less, H_TwoPressure by introducing gas
At 1.3 Pa, a pulse voltage was applied to the device. pulse
When the peak value gradually rises from 0V and reaches 6V
Then, the ascent was stopped and fixed. The pulse width is T₁= 100μ
Seconds, pulse interval is T_Two= 833 μs, ie frequency
F = 1200 Hz. At the same time,
A certain switching control circuit 1403 includes Dx1 to Dx2
0 of the external terminal is a pulse generator 1402
And the other is connected to ground, _TwoSynchronized with the pulse
The terminals connected to the generator are sequentially from Dx1 to Dx20,
Operate to switch cyclically. Therefore, individual
The pulse width is T₁= 100 μs, pulse
The interval is T_Two= 16.7 μsec, that is, f =
This means that a 60 Hz pulse is applied. Soshi
The pulse crest value was kept at 6V and held for 10 minutes
At this time, the pulse peak value and the device current were calculated for each X-direction wiring.
Resistance (electron discharge connected to the same X-direction wiring)
16.7 kΩ (parallel resistance of 60 output elements)
Stop applying pulse because the resistance value exceeded 1MΩ)
Then, the inside of the envelope was evacuated again.

(Comparative Example 2): Enclosure 8 as in Example 2
Evacuating the inside 8 was lowered below 1.3 × 10 ^-4 Pa but, H ₂
No gas was introduced. Thereafter, the same pulse as in Example 2 was applied, the peak value was fixed at 6 V, and the pulse was held for 10 minutes.
During this time, the device current gradually decreased. Thereafter, when the pulse width was changed to T _{1 ′} = 500 μsec, the resistance obtained from the pulse peak value and the device current was 1 for each X-direction wiring.
Since it exceeded 6.7 kΩ, pulse application was stopped.

(Comparative Example 3): Enclosure 8 as in Example 2
Evacuating the inside 8 was lowered below 1.3 × 10 ^-4 Pa but, H ₂
No gas was introduced. Thereafter, of the X-direction wirings, Dx
1 is connected to the pulse generator 1402 and the pulse width is T
₁ = 100 μsec, and a pulse having a pulse interval of T ₂ = 16.7 msec, that is, a pulse having a frequency of f = 60 Hz was applied. The pulse peak value was changed in the same manner as in Example 2. After holding at 6 V for 10 minutes, T ₁ was changed to 500 μs, and the resistance value was 1
The pulse application was stopped after confirming that it exceeded 6.7 kΩ. Thereafter, the switching circuit is switched, and the forming process of the next element row is similarly performed.
All 0 rows were subjected to forming processing.

(Comparative Example 4): Enclosure 8 as in Example 2
Evacuating the inside 8 was lowered below 1.3 × 10 ^-4 Pa but, H ₂
No gas was introduced. Thereafter, the pulse width T ₁ = 100
A pulse having a pulse interval of μsec and a pulse interval T ₂ = 833 μsec was applied. The operation of the switching circuit 1403 was the same as that of the second embodiment. Therefore, as in the second embodiment, the individual electron-emitting devices have a pulse width of T ₁ = 100 μsec and a pulse interval of T _2.
= 16.7 μsec, that is, a pulse having a frequency of f = 60 Hz is applied. The pulse peak value was gradually increased in steps of 0.1 V. When the pulse peak value reached 12 V, the resistance value of each element row was successively 16.7 kΩ.
, The application of the pulse was stopped.

The electron emitting portion 2 thus formed has a width of 10 nm (Example 2) and a width of 15 nm (Comparative Example 2,
The cracks of Comparative Example 3) were formed uniformly. In Comparative Example 4, an uneven crack having a width of 100 to 200 nm was formed.

Next, an activation process was performed by driving a device by applying a pulse voltage. As the pulse voltage, a rectangular wave pulse is used, and the pulse width, the pulse interval, and the operation of the switching circuit are set to the peak value of the pulse voltage of 15 V, the acetone is introduced into the envelope 88, and the pressure is increased. Was set to 1.3 × 10 ⁻² Pa, and the measurement was performed while measuring the device current _If .

Thereafter, a stabilizing step was performed. Envelope 88
Was exhausted while heating to 160 ° C., and the internal pressure was set to 1.3.
After the pressure was set at ^10-5 Pa, an exhaust pipe (not shown) was welded by heating with a gas burner, and the envelope 88 was sealed.
Finally, gettering was performed by a high-frequency heating method to maintain the degree of vacuum after sealing.

In the image forming apparatus completed as described above, the external terminals Dx1 to Dx20 and Dy1 to Dy6
0, a scanning signal and a modulation signal are applied from a signal generating means (not shown) to emit electrons, and a high voltage of 7 kV is applied to the metal back 85 through a high voltage terminal 87 to accelerate the electron beam, thereby causing the fluorescent film 84 to emit light. Then, the image was displayed by exciting and emitting light. As a result, a uniform and good image was displayed.

At the same time, the current flowing into the high voltage terminal 87 was measured, and the emission current _Ie was measured. For each device,
Average I _e and row-by-row variation △ I _e per row (60 devices) are shown in Table 1.

[0174]

[Table 1]

_Ie of the electron source according to Example 2 is the same as Comparative Example 2
４4 are larger than those of the electron sources. Further, ΔI _e of the electron sources according to Example 2 and Comparative Examples 2 and 3 is much smaller than that of the electron source according to Comparative Example 4, and the uniformity is high. This is because the electron emission portions of the electron emission elements constituting the electron sources of Example 2 and Comparative Examples 2 and 3 hold the pulse peak value at V _h (6 V) in the energization forming process. In contrast, in Comparative Example 4, while the pulse peak value gradually increased to 12 V, electron emission was performed at various voltages corresponding to variations in resistance values (before forming processing) of each element. The formation of the electron-emitting portion is sufficiently uniform because the pulse voltage itself is higher than that of Example 2 and Comparative Examples 2 and 3 and the input power for forming the electron-emitting portion is large. Probably because it was not done.

Embodiment 3 FIG. 17 shows an image forming apparatus 201 (display panel) according to Embodiment 2 of the present invention.
FIG. 2 is a diagram illustrating an example of a display device configured to be able to display image information provided from various image information sources such as a television broadcast.

In the figure, reference numeral 201 denotes a display panel;
1 is a display panel driving circuit, 1002 is a display controller, 1003 is a multiplexer, 10
04 is a decoder, 1005 is an input / output interface circuit, 1006 is a CPU, 1007 is an image generation circuit, 10
08, 1009 and 1010 are image memory interface circuits, 1011 is an image input interface circuit, 1012 and 1013 are TV signal receiving circuits, 101
Reference numeral 4 denotes an input unit.

When the present image forming apparatus receives a signal including both video information and audio information, such as a television signal, it naturally reproduces the audio simultaneously with the display of the video. Descriptions of circuits, speakers, and the like related to reception, separation, reproduction, processing, storage, and the like of audio information that are not directly related to the features of the present invention are omitted.

Hereinafter, the function of each section will be described along 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 format of the received TV signal is not particularly limited. For example, NTSC, PAL, SEC
Any method such as the AM method may be used. Further, a TV signal comprising a larger number of scanning lines than these, for example, a so-called high-definition TV including the MUSE system is a signal suitable for taking advantage of the display panel suitable for a large area and a large number of pixels. Source.

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

[0183] The TV signal receiving circuit 1012 is a circuit for receiving a TV signal transmitted using a wired transmission system such as a coaxial cable or an optical fiber. Similarly 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. The captured image signal is output to the decoder 1004.

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

Image memory interface circuit 100
Reference numeral 9 denotes a circuit for capturing an image signal stored in the video disk.
004 is output.

Image memory interface circuit 100
Reference numeral 8 denotes a circuit for taking in an image signal from a device storing still image data, such as a still image disk. The taken still image data is input to the decoder 1004.

The input / output interface circuit 1005
A circuit for connecting the display device to an external computer, a computer network, or an output device such as a printer. In addition to inputting and outputting image data and character / graphic information, control signals and numerical data can be input and output between the CPU 1006 of the image forming apparatus and the outside in some cases. .

The image generating circuit 1007 is provided with image data, character / graphic information input from outside via the input / output interface circuit 1005, or the CPU 100.
6 is a circuit for generating display image data based on the image data and character / graphic information output from 6. Inside this circuit, for example, a rewritable memory for storing image data and character / graphic information, a read-only memory storing an image pattern corresponding to a character code, a processor for performing image processing, etc. And other circuits necessary for generating an image.

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

The CPU 1006 mainly performs operations related 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, and image signals to be displayed on the display panel are appropriately selected or combined. In that case, the display panel controller 1
A control signal is generated for 002 to appropriately control the operation of the display device such as the screen display frequency, the scanning method (for example, interlaced or non-interlaced), and the number of scanning lines on one screen. In addition, image data and character / graphic information are directly output to the image generation circuit 1007, or an external computer or memory is accessed via the input / output interface circuit 1005 to convert the image data or character / graphic information. input.

It should be noted that the CPU 1006 may be involved in operations for other purposes. For example, it may directly relate 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
The computer may be connected to an external computer network via a computer, and work such as numerical calculation may be performed in cooperation with an external device.

The input unit 1014 is used by a user to input commands, programs, data, and the like to the CPU 1006. For example, in addition to a keyboard and a mouse, various inputs such as a joystick, a barcode reader, and a voice recognition device. Input devices 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 inversely converting a luminance signal into an I signal and a Q signal. As shown by the dotted line in FIG.
4 preferably has an image memory inside. This is for handling a television signal that requires an image memory when performing inverse conversion, such as the MUSE method.

The provision of the image memory facilitates the display of a still image. Alternatively, the image generation circuit 1007
And cooperate with the CPU 1006 to perform image thinning, interpolation,
There is an advantage that image processing and editing including enlargement, reduction, and composition become easy.

The multiplexer 1003 is connected to the CPU 1
A display image is appropriately selected based on a control signal input from 006. That is, the multiplexer 1003
Selects a desired image signal from the inversely converted image signals input from the decoder 1004 and selects a driving circuit 1001
Output to In that case, by switching and selecting an image signal 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. .

Display panel controller 1002
Is a circuit for controlling the operation of the drive circuit 1001 based on a control signal input from the CPU 1006.

As a signal related to the basic operation of the display panel, for example, a signal for controlling an operation sequence of a power supply (not shown) for driving the display panel is output to the drive circuit 1001. For example, a signal for controlling a screen display frequency and a scanning method (for example, interlaced or non-interlaced) is output to the driving circuit 1001 as a signal related to the display panel driving method. In some cases, a control signal relating to image quality adjustment such as luminance, contrast, color tone, and sharpness of a display image may be output to the driving circuit 1001.

A drive circuit 1001 is a circuit for generating a drive signal to be applied to the display panel 201, and is based on an image signal input from the multiplexer 1003 and a control signal input from the display panel controller 1002. It works.

The function of each section has been described above. With the configuration illustrated in FIG. 17, in the present image forming apparatus, image information input from various image information sources can be displayed on the display panel 201. . That is, various image signals including television broadcasting are transmitted to the decoder 10.
After the inverse conversion at 04, the multiplexer 1003
Is appropriately selected and input to the driving 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 an image signal to be displayed. The drive circuit 1001 controls the display panel 2 based on the image signal and the control signal.
01 is applied with a drive signal. Thus, an image is displayed on the display panel 201. These series of operations are totally controlled by the CPU 1006.

In the present image forming apparatus, the image memory built in the decoder 1004 and the image generating circuit 100
7 and information selected from the information, as well as, for example, enlargement, reduction, rotation, movement, edge enhancement, thinning, interpolation, color conversion, image aspect ratio conversion, etc., for the image information to be displayed. It is also possible to perform image processing such as initial image processing and image editing such as combining, erasing, connecting, exchanging, and fitting. Although not specifically mentioned in the description of the present embodiment, a dedicated circuit for processing and editing audio information may be provided as in the above-described image processing and image editing.

Therefore, the present image forming apparatus can be used for a television broadcast display device, a video conference terminal device, an image editing device for handling still images and moving images, a computer terminal device,
It can be equipped with the functions of a word processor and other office terminal equipment, game machines, and the like, and has a very wide range of applications for industrial or consumer use.

FIG. 17 shows only an example of the configuration of an image forming apparatus using a display panel using a surface conduction electron-emitting device as an electron beam source, and an image to which the present invention can be applied. It goes without saying that the forming apparatus is not limited to this.

For example, of the components shown in FIG. 17, circuits relating to functions not required for the intended use may be omitted.
Conversely, additional components may be added depending on the purpose of use. For example, when this display device is applied as a video phone, a TV camera, a voice microphone,
It is preferable to add an illuminator, a transmitting / receiving circuit including a modem, and the like to the components.

In the present image forming apparatus, in particular, since the display panel 201 according to the present invention can be easily made thin, the depth of the display device can be reduced. In addition, since it is easy to enlarge the screen, the brightness is high, and the viewing angle characteristics are excellent, it is possible to display an image full of a sense of reality and full of power with good visibility.

In addition, by using an electron source having uniform and stable electron emission characteristics, a high-quality color flat television having excellent color reproducibility without variation has been realized.

[0208]

As described above, according to the present invention, a uniform and stable electron-emitting device can be obtained, and a large number of electron-emitting devices are arrayed to emit electrons according to an input signal. In the electron source, uniform and stable electron emission can be performed from each electron-emitting device. Further, in an image forming apparatus using such an electron source, a high-quality image with little variation in luminance and excellent operation stability is provided. Can be displayed.

As described above, according to the present invention, a large-area flat display which can deal with a color image, has a small variation in luminance, is excellent in operation stability, and has high display quality is realized.

[Brief description of the drawings]

FIG. 1 is a schematic view of a planar surface conduction electron-emitting device which is an example of an electron-emitting device applicable to the present invention.

FIG. 2 is a schematic view of a vertical surface conduction electron-emitting device as an example of an electron-emitting device applicable to the present invention.

FIG. 3 is a diagram for explaining an example of a method of manufacturing the surface conduction electron-emitting device of FIG.

FIG. 4 is an example of a voltage waveform that can be used for forming processing according to the present invention.

FIG. 5 is a schematic configuration diagram illustrating an example of a vacuum processing apparatus (measurement and evaluation apparatus) that can be used for manufacturing an electron-emitting device applicable to the present invention.

FIG. 6 is a diagram showing electron emission characteristics of an electron-emitting device applicable to the present invention.

FIG. 7 is a schematic configuration diagram of an electron source having a simple matrix arrangement to which the present invention can be applied.

FIG. 8 is a schematic configuration diagram of a display panel used in an image forming apparatus using an electron source having a simple matrix arrangement.

FIG. 9 is a diagram showing a fluorescent film in the display panel of FIG.

FIG. 10 is a diagram illustrating an example of a drive circuit that drives the display panel of FIG. 8;

FIG. 11 is a schematic plan view of a ladder type electron source to which the present invention can be applied.

FIG. 12 is a schematic configuration diagram of a display panel used in an image forming apparatus using a ladder-type electron source.

FIG. 13 is a partial plan view of an electron source having a simple matrix arrangement according to an embodiment of the present invention.

14 is a partial cross-sectional view of the electron source of FIG.

FIG. 15 is a view illustrating a method of manufacturing the electron source in FIG.

FIG. 16 is a diagram for explaining a method of manufacturing the electron source of FIG.

FIG. 17 is a block diagram illustrating an image forming apparatus according to a fourth embodiment.

FIG. 18 is a plan view of a conventional surface conduction electron-emitting device.

FIG. 19 is a diagram showing a wiring diagram of a forming process in the embodiment.

FIG. 20 is an example of a voltage waveform that can be used for forming processing according to the present invention.

FIG. 21 is a schematic diagram illustrating a relationship between a pulse peak value and an element resistance according to a method of an energization forming process.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 Electron emission part 3 Conductive film 4,5 Element electrode 21 Step formation part 50 Ammeter 51 Power supply 52 Ammeter 53 High voltage power supply 54 Anode electrode 55 Vacuum container 56 Exhaust pump 71 Electron source board 72 X direction wiring 73 Y direction Wiring 74 Surface conduction electron-emitting device 75 Connection 81 Rear plate 82 Support frame 83 Glass substrate 84 Phosphor film 85 Metal back 86 Face plate 87 High voltage terminal 88 Enclosure 91 Black conductive material 92 Phosphor 101 Display panel 102 Scanning circuit 103 Control Circuit 104 Shift register 105 Line memory 106 Synchronous signal separation circuit 107 Modulation signal generator 110 Electron source substrate 111 Electron emitting element 112 Common wiring 120 Grid electrode 121 Opening 131 Interlayer insulating layer 132 Contact hole 133 Cr film 134 Pt film 01 display panel 1201 substrate 1202 electron-emitting portion 1203 conductive film 1401 common electrode 1402 pulse generator 1403 controls switching circuit

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yasuhiro Hamamoto 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Masato Yamanobe 3-30-2 Shimomaruko, Ota-ku, Tokyo Kia Within Non Corporation (72) Inventor Masanori Sandome 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Corporation

Claims (12)

[Claims] 1. A method for manufacturing an electron-emitting device, comprising: arranging a conductive film on a substrate; and applying a pulsed voltage to the conductive film in an atmosphere containing a reducing substance. And an energizing step of forming an electron-emitting portion in the conductive film. 2. The method according to claim 1, wherein the reducing substance is a substance selected from H ₂ , CO, and an organic substance. 3. The method according to claim 1, wherein the pulse-like voltage is applied a plurality of times at predetermined intervals. 4. When the pulse width of the pulse voltage is T ₁ and the interval period is T ₂ , T ₂ ≧ 5 ×
Satisfy T _1, the manufacturing method of the electron-emitting device according to claim 3, characterized in that. 5. The method according to claim 1, wherein a peak value of the pulse voltage applied to the conductive film gradually increases. 6. The method according to claim 5, wherein the peak value of the pulse-like voltage applied to the conductive film gradually increases to a predetermined value, and is thereafter maintained at a constant value. A method for manufacturing the electron-emitting device according to the above. 7. The electron-emitting device according to claim 5, wherein the peak value of the pulse voltage applied to the conductive film is maintained at a predetermined value, and thereafter gradually increases. Manufacturing method. 8. The method according to claim 1, further comprising, after the energizing step, a step of disposing carbon, a carbon compound, a metal, or a metal compound in the electron-emitting portion. The manufacturing method of the electron-emitting device of the above. 9. The step of arranging carbon or a carbon compound or a metal or a metal compound in an electron-emitting portion includes the step of energizing the conductive film in an atmosphere containing an organic substance or an atmosphere containing a metal compound. The method for manufacturing an electron-emitting device according to claim 8, wherein: 10. The electron-emitting device according to claim 9, wherein the energization in the atmosphere containing an organic substance or the atmosphere containing a metal compound is a step of repeatedly applying a pulsed voltage. Production method. 11. A method of manufacturing an electron source having a plurality of electron-emitting devices, wherein the electron-emitting devices are arranged in the same manner.
0. A method for producing an electron source, wherein the method is produced by the method according to any one of the above items. 12. A method for manufacturing an image forming apparatus having an electron source and an image forming member, wherein the electron source is provided.
2. A method for manufacturing an image forming apparatus, wherein the method is performed by the method according to 1.