JP3619205B2 - Electron emitting device, electron source, and image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electron-emitting device, an electron source using a plurality of the devices, and an image forming apparatus such as a display device or an exposure device using these devices.
[0002]
[Prior art]
Conventionally, two types of electron-emitting devices using a thermionic electron-emitting device source and a cold cathode electron-source electron-emitting device are known. Cold cathode electron emission element sources include field emission type (hereinafter referred to as “FE type”), metal / insulating layer / metal type (hereinafter referred to as “MIM type”), surface conduction type electron emission element, and the like. As an example of the FE type, W.W. P. Dyke & W. W. Dolan, “Field emission”, Advance in Electricon Physics, 8, 89 (1956) or C.I. A. Spindt, “PHYSICAL Properties of Thin-Film Field Emission Catalysts with Mollybdenum Cones”, J. et al. Appl. Phys. 47, 5248 (1976), etc. are known.
[0003]
Examples of the MIM type include C.I. A. Mead, “Operation of Tunnel-Emission Devices”, J. Am. Apply. Phys. , 32, 646 (1961), etc. are known.
[0004]
Examples of surface conduction electron-emitting devices include M.I. I. Elinson, Recio Eng. Electron Phys. , 10, 1290, (1965) and the like.
[0005]
The surface conduction electron-emitting device utilizes a phenomenon in which electron emission occurs when a current flows through a small-area thin film formed on a substrate in parallel to the film surface. As this surface conduction electron-emitting device, SnOl by Erinson et al.₂Thin film, Au thin film [G. Dittmer: “Thin Solid Films”, 9, 317 (1972), In₂O₃/ SnO₂By thin film [M. Hartwell and C.H. G. Fonstad: “IEEE Trans. ED Conf.” 519 (1975)], carbon thin film [Hisaki Araki et al .: Vacuum, Vol. 26, No. 1, page 22 (1983)] and the like have been reported.
[0006]
As typical examples of these surface conduction electron-emitting devices, the above-mentioned M.P. A device structure of Hartwell is schematically shown in FIG. In the figure, reference numeral 111 denotes a substrate. Reference numeral 114 denotes a conductive film, which is made of a metal oxide thin film or the like formed by sputtering in an H-shaped pattern, and an electron emission portion 115 is formed by energization treatment. In the figure, the element electrode interval L is set to 0.5 to 1 mm, and W ′ is set to 0.1 mm.
[0007]
Conventionally, in these surface conduction electron-emitting devices, it is common to form an electron-emitting portion 115 by applying an energization process called energization forming to the conductive film 114 in advance before electron emission. That is, a DC voltage or a pulse voltage is applied to both ends of the conductive film 114, and the conductive film 114 is locally destroyed, deformed, or altered to form an electron emitting portion 115 that is in an electrically high resistance state. It is. At this time, a crack occurs in a part of the conductive film 114, and a minute gap is formed.
[0008]
The surface conduction electron-emitting device in which the minute gap is formed emits electrons from the electron emission portion 115 (near the minute gap) by applying a voltage to the conductive film 114 and causing a current to flow through the device. is there.
[0009]
If an electron source substrate on which a plurality of electron-emitting devices as described above are formed is used, an image forming apparatus can be configured by combining with an image forming member made of a phosphor or the like.
[0010]
However, the above-mentioned M.I. Hartwell's electron-emitting devices do not always have satisfactory electron-emitting characteristics and electron-emitting efficiency, and image forming apparatuses with high brightness and excellent operational stability using these elements It was actually very difficult to provide.
[0011]
Therefore, for example, JP-A-08-264112, JP-A-08-162015, JP-A-09-027268, JP-A-09-027272, JP-A-10-003848, JP-A-10-003847, JP-A-10-003853, JP-A-10-003854. As disclosed in Japanese Patent Publication No. Gazette and the like, there is a case where a process called an activation process is performed. The activation treatment process is a process in which the device current I_f, Emission current I_eIs a process in which changes significantly.
[0012]
The activation step can be performed by repeatedly applying a pulse voltage to the element in the same manner as the forming process in an atmosphere containing an organic substance. By this treatment, a film made of carbon or a carbon compound is deposited at least on the electron emission portion of the element from an organic substance present in the atmosphere, and the element current I_f, Emission current I_eHowever, it changes significantly, and better electron emission characteristics can be obtained.
[0013]
An example of a conventional method for manufacturing an electron-emitting device will be described with reference to FIG.
[0014]
First, the first electrode 2 and the second electrode 3 are disposed on the substrate 1 (FIG. 19A).
[0015]
Next, the conductive film 4 connecting the first and second electrodes is disposed (FIG. 19B).
[0016]
Then, the forming process described above is performed. Specifically, the second gap 6 is formed in a part of the conductive film 4 by passing a current through the conductive film (FIG. 19C).
[0017]
Further, the activation process described above is performed. Specifically, the carbon film 10 is disposed on the substrate 1 in the second gap 6 and the conductive film 4 in the vicinity thereof by passing a current through the conductive film. By this activation process, the first gap 7 narrower than the second gap is formed, and the electron emission portion 5 is formed (FIG. 19D).
[0018]
[Problems to be solved by the invention]
In order for an image forming apparatus to which an electron-emitting device is applied to stably display a bright image, it is desirable to have a technique that can maintain a higher electron emission efficiency and stable electron emission characteristics for a longer time. ing.
[0019]
The electron emission efficiency referred to here is a current flowing between electrodes when a voltage is applied between a pair of opposing device electrodes of the electron-emitting device (hereinafter referred to as device current I)._fCurrent discharged into the vacuum against the current (hereinafter referred to as emission current I)_eIt is called the ratio.
[0020]
If high electron emission efficiency can be stably controlled over a long period of time, for example, in an image forming apparatus using a phosphor as an image forming member, it is possible to realize a high-quality image forming apparatus such as a flat TV with low power. Become.
[0021]
In order to use in such an application, a practical voltage (for example, 10V to 20V) is sufficient for the emission current I._eThe emission current I_eAnd element current I_fDoes not fluctuate significantly during driving, the emission current I over a long time_eAnd element current I_fIs required not to deteriorate.
[0022]
However, the conventional method for manufacturing a surface conduction electron-emitting device described above has the following problems.
[0023]
Device characteristics such as electron emission efficiency and lifetime of the device depend on the structure and stability of the carbon film 10 (see FIG. 19D) made of carbon or a carbon compound deposited by the activation process.
[0024]
Further, the shape of the second gap 6 formed by the forming process described above may be formed in a shape with a non-uniform width as schematically shown in FIG. FIG. 20 is a schematic plan view of an element (FIG. 19C) subjected to a forming process. Further, the second gap 6 formed by the forming process may meander significantly between the electrodes 2 and 3. Thus, if the shape of the second gap 6 formed by the forming process is non-uniform, the electric field generated in the gap 6 becomes non-uniform when a voltage is applied between the device electrodes 2 and 3.
[0025]
Even in the element having the non-uniform second gap 6, the carbon film 10 made of carbon or a carbon compound is made conductive on the substrate 1 in the gap 6 and in the vicinity thereof by performing the activation step described above. By depositing on the film 4, the gap 6 can be filled and the width of the gap can be substantially reduced.
[0026]
As a result, the variation in the width of the gap 6 formed by the forming process can be reduced, and the emission current I_eAnd element current I_fCan be increased.
[0027]
However, even if the activation step is performed, the non-uniformity of the distance from the device electrodes 2 and 3 to the gap 6 (meandering of the gap 6) is not basically reduced.
[0028]
Further, depending on the non-uniformity of the width of the gap 6 formed by the forming process, the deposition amount of the carbon film 10 formed by the activation process may be non-uniform.
[0029]
Due to these non-uniformities, when a voltage is applied between the device electrodes 2 and 3, the voltage effectively applied to the first gap 7 portion becomes non-uniform, and the emission current I depends on the region._eMay occur, or a region that is easily deteriorated due to a large electric field locally may occur.
[0030]
Then, the required electron emission efficiency cannot be obtained, or the emission current I_eMay vary from element to element, and characteristics may vary or deteriorate during driving.
[0031]
Therefore, in order to realize a high-quality image forming apparatus that can be applied to a flat TV or the like using an electron-emitting device, carbon having a more suitable structure and stability in the electron-emitting portion of the electron-emitting device or It is necessary to form a carbon film made of a carbon compound.
[0032]
In view of the above problems, the present invention achieves a method for manufacturing an electron-emitting device that achieves good electron emission characteristics uniformly and stably over a long period of time, and manufactures an electron source and an image forming apparatus using the manufacturing method. An electron-emitting device, an electron source, and an image forming apparatus excellent in high-luminance and uniform display characteristics using the electron source. Is to provide.
[0033]
[Means for Solving the Problems]
The present inventionA pair of conductive films arranged opposite each other with a gap, and a gap narrower than the gap is formed in the gap, which is arranged on the conductive film and in the gap.Carbon filmWhenAn electron-emitting device havingThe carbon film on the conductive film in the film thickness directionThe specific resistance is 0.001 Ωm or less.
[0034]
The electron-emitting device of the present invention can be preferably applied to an electron source having a plurality of electron-emitting devices.
[0035]
The electron-emitting device of the present invention can be preferably applied to an image forming apparatus having an electron source and an image forming member.
[0036]
The method for manufacturing an electron-emitting device according to the present invention includes a step of disposing a conductive member having a second gap on a substrate, and an electron-emitting means disposed away from the conductive member in an atmosphere containing a carbon compound. And irradiating at least the second gap with an electron beam, and applying a voltage to the conductive member in an atmosphere containing a carbon compound.
[0037]
The method of manufacturing an electron-emitting device according to the present invention includes a step of disposing a first conductive member and a second conductive member with a second gap on a substrate, and the conductive property in an atmosphere containing a carbon compound. A step of irradiating at least the second gap with an electron beam from an electron emitting means disposed away from the member; and a voltage between the first and second conductive members in an atmosphere containing a carbon compound. And an applying step.
[0038]
The method for manufacturing an electron-emitting device according to the present invention includes a step of disposing a conductive member having a second gap on a substrate, and an electron disposed apart from the conductive member in an atmosphere containing a carbon compound. Applying a voltage to the conductive member while irradiating at least the second gap with an electron beam from the emitting means.
[0039]
The method of manufacturing an electron-emitting device according to the present invention includes a step of disposing a first conductive member and a second conductive member with a second gap on a substrate, and the conductive property in an atmosphere containing a carbon compound. Applying a voltage between the first and second conductive members while irradiating an electron beam to at least the second gap from an electron emitting means arranged away from the member. And
[0040]
The method of manufacturing an electron-emitting device according to the present invention includes a step of disposing a conductive member having a second gap on a substrate, and applying a voltage to the conductive member in an atmosphere containing a carbon compound. And irradiating at least the second gap with an electron beam from an electron emitting means arranged away from the conductive member within a certain period.
[0041]
In the method of manufacturing an electron-emitting device according to the present invention, the first and second conductive members are disposed on the substrate with a second gap, and the first and second conductive members are disposed in an atmosphere containing a carbon compound. And irradiating at least the second gap with an electron beam from an electron emission means disposed away from the conductive member within a period in which a voltage is applied between the second conductive member and It is characterized by having.
[0042]
Moreover, the manufacturing method of the present invention can be preferably applied to a manufacturing method of an electron source having a plurality of electron-emitting devices.
[0043]
The manufacturing method of the present invention can be preferably applied to a manufacturing method of an image forming apparatus having an electron source and an image forming member.
[0044]
DETAILED DESCRIPTION OF THE INVENTION
Next, an example of the manufacturing method of this invention is demonstrated in detail using FIG.1, FIG.2, FIG.4.
[0045]
1A and 1B are schematic views showing a configuration of a surface conduction electron-emitting device to which the present invention is preferably applied. FIG. 1A is a plan view and FIG. 1B is a cross-sectional view. 2 and 4 are schematic views showing a part of the production method of the present invention.
[0046]
1, 2, and 4, 11 is a substrate, 12 and 13 are element electrodes, 14 is a conductive film, 15 is a carbon film containing carbon as a main component (conductive film), 100 is an electron emission portion, 16 Is the second gap, and 17 is the first gap.
[0047]
(Process A)
First, opposing electrodes 12 and 13 are formed. For this purpose, the substrate 11 is sufficiently cleaned using a detergent, pure water, an organic solvent, and the like, and electrode materials are deposited by a vacuum deposition method, a sputtering method, and the like, and then the electrodes 12, 13 are formed on the substrate 11 using a photolithography technique. Is formed (FIG. 2A). Alternatively, the electrode can be formed by a printing method such as an offset printing method. It is preferable to use a printing method, and in particular, an offset printing method, since it can be formed in a large area at a low cost.
[0048]
In the present invention, the substrate 11 is made of SiO, formed by sputtering or the like on glass, quartz glass, blue plate glass, blue plate glass with a reduced content of impurities such as Na.₂It is also possible to use a glass substrate, ceramics, Si substrate, and the like laminated.
[0049]
As a material for the electrodes 12 and 13, a general conductor material can be used. For example, metals or alloys such as Ni, Cr, Au, Mo, W, Pt, Ti, Al, Cu, Pd, and Pd, Ag, Au, RuO₂, Pd-Ag or other metals or metal oxides, or printed conductors composed of any of the above metals, alloys, metal oxides and glass, or In₂O₃-SnO₂It is appropriately selected from a transparent conductor such as a semiconductor conductor material such as polysilicon.
[0050]
The element electrode interval L, the element electrode length W, the shape of the conductive film 14 and the like are designed in consideration of the applied form and the like. The element electrode interval L is preferably in the range of several hundreds of nanometers to several hundreds of micrometers, and more preferably in the range of several micrometers to several tens of micrometers in consideration of the voltage applied between the element electrodes.
[0051]
The element electrode length W is preferably in the range of several μm to several hundred μm in consideration of the resistance value of the electrode and electron emission characteristics, and the film thickness d of the element electrodes 12 and 13 is preferably several tens of nm to several It is in the range of μm.
[0052]
Not only the configuration shown in FIG. 1 but also a configuration in which the conductive film 14 and the opposing element electrodes 12 and 13 are stacked in this order on the substrate 1 can be adopted.
[0053]
(Process B)
Next, the conductive film 14 is formed. For example, an organometallic solution is applied to the substrate 11 provided with the electrodes 12 and 13 to form an organometallic film. The organometallic solution is a solution of an organometallic compound containing the metal of the material of the conductive film 14 as a main element. This organometallic film is heated and baked and patterned by lift-off, etching, or the like to form a conductive film 14 (FIG. 2B). Here, the application method of the organic metal solution has been described, but the method of forming the conductive film 4 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, an ink jet method, or the like can be used.
[0054]
When the ink jet method is used, microdroplets of about 10 ng to several tens of ng can be generated with good reproducibility and applied to the substrate, and photolithography patterning and vacuum processes are not required. To preferred. As an apparatus for the ink jet method, a bubble jet (registered trademark) type using an electrothermal transducer as an energy generating element, a piezo jet type using a piezoelectric element, or the like can be used. As the droplet firing means, electromagnetic wave irradiation means, heated air irradiation means, and means for heating the entire substrate are used. As the electromagnetic wave irradiation means, for example, an infrared lamp, an argon ion laser, a semiconductor laser, or the like can be used.
[0055]
The material constituting the conductive film 14 is a metal such as Pd, Pt, Ru, Ag, Au, Ti, In, Cu, Cr, Fe, Zn, Sn, Ta, W, Pd, PdO, SnO.₂, In₂O₃, PbO, Sb₂O₃Oxides such as HfB₂, ZrB₂, LaB₆, CeB₆, YB₄, GdB₄Borides such as TiC, ZrC, HfC, carbides such as Ta, C, SiC, and WC, nitrides such as TiN, ZrN, and HfN, and semiconductors such as Si and Ge can be used.
[0056]
The film thickness of the conductive film 14 is appropriately set in consideration of the step coverage to the device electrodes 12 and 13, the resistance value between the device electrodes 12 and 13, etc., but is usually in the range of several to several hundred nm. And more preferably in the range of 1 nm to 50 nm. Its resistance value is 1 × 10 Rs²~ 1x10⁷It is the value of Ω / □. Rs is a value when a resistance R measured in the length direction of a thin film having a width w and a length l is R = Rs (l / w).
[0057]
(Process C)
Next, a forming process for forming the second gap 16 in the conductive film 14 is performed. Specifically, by applying a voltage (particularly a pulse voltage) between the pair of electrodes 12 and 13 and passing a current through the conductive film 14, a part of the conductive film 14 is formed. A micro gap 16 having a locally changed structure such as destruction, deformation, or alteration is formed (FIG. 2C). In the figure, the conductive film 14 is shown as being completely separated on the left and right sides with the gap 16 as a boundary. Therefore, the conductive film 14 in which the gap 16 is formed by performing the forming process can be referred to as a pair of conductive films (conductive members) 14 facing each other with the gap 16 interposed therebetween. It can also be said to be a conductive film (conductive member) 14.
[0058]
An example of a voltage waveform in the energization process is shown in FIG. In FIG. 3, the pulse width T₁Is 1 μsec to 10 msec, pulse interval T₂Is freely set in the range of 10 μsec to 10 msec. The peak value of the triangular wave is selected according to the material and thickness of the conductive film. Under the above conditions, a pulse voltage is applied for several seconds to several tens of minutes. Completion of the formation of the gap 16 may be determined by measuring a current value at the time of applying a voltage and when the current value is equal to or less than a set value. For example, a current flowing by applying a voltage of about 0.1 V is measured, a resistance value is obtained, and when a resistance of 1 MΩ or more is indicated, the energization forming is terminated.
[0059]
(Process D)
On the conductive film 14 having the second gap 16 formed as described above, an activation process is performed to form a carbon film (conductive film) 15 mainly composed of carbon (FIG. 2D). )). By this process, the device current I_f, Emission current I_eCan be significantly increased.
[0060]
In the present invention, in this activation step, as shown in FIG. 4, an electron emitting means 41 is separately provided outside the electron emitting device, and an electron beam emitted from the electron emitting means is placed near the gap 16. While irradiating one of the following areas (1) to (3), a voltage is applied between the electrodes 12 and 13 to form a conductive film (carbon film) 15 mainly composed of carbon. That is, a voltage is applied between the electrodes 12 and 13 simultaneously with the electron beam irradiation from the electron emitting means.
[0061]
As the irradiation region of the electron beam,
(1) the substrate 11 in the gap 16;
(2) The substrate 11 in the gap 16 and the conductive film 14 in the vicinity thereof,
Or
(3) The substrate 11 and the conductive film 14 in the gap 16 as well as the electrodes 12, 13,
One of them. Preferably, the region (3) is irradiated.
[0062]
In the activation step, the voltage application between the electrodes 12 and 13 is preferably performed by repeatedly applying a pulse voltage. Further, in the present invention, preferably, a bipolar pulse voltage is applied as shown in FIGS.
[0063]
The carbon film 15 is applied to the outside of the electron-emitting device in addition to repeating application of a pulse voltage to the conductive film 14 (between the pair of electrodes 12 and 13) in an atmosphere containing a carbon compound gas (organic substance gas). It can be formed by irradiating the vicinity of the gap 16 with an electron beam emitted from the electron emission means 41 provided on the surface.
[0064]
In FIG. 4, the element and the electron emission means 41 are installed in the same vacuum container. The electron emission means 41 may be a structure that uses a hot cathode as an electron beam source and accelerates by applying an acceleration voltage.
[0065]
The electron beam emitted from the electron emission means 41 does not need to be confined only in the gap 16, and the gap 16 is formed in consideration of the voltage applied between the electrodes 12 and 13, the partial pressure of the carbon compound gas at the time of activation, and the like. It is preferable to have a spread of several μm or more as the center.
[0066]
However, when an electron beam is irradiated to a very wide area, there is a possibility that the carbon compound is deposited even in an unnecessary area. Therefore, it is preferable that the electron beam emitted from the electron emission means 41 is shielded by the electron beam shielding means 42 to suppress the spread.
[0067]
The acceleration voltage is preferably set to about 1 kV to 20 kV. That is, it is preferable to irradiate an electron beam having an energy of 1 keV or more and 20 keV or less. The electron beam irradiation may be performed continuously (in a DC manner), or may be performed in synchronization with a pulse voltage applied between the electrodes 12 and 13. It is preferable that the voltage applied to the element electrode is pulsed while preferably irradiating continuously (in a DC manner).
[0068]
In the activation step of the present invention, it is preferable to apply a voltage between the device electrodes 12 and 13 while irradiating the electron beam from the electron emission means 41. That is, during the period in which the voltage is applied between the device electrodes 12 and 13, the electron beam from the electron emission means is irradiated to any one of the above-mentioned (1) to (3).
[0069]
The carbon film 15 formed by the activation process of the present invention is connected to each of the electrodes 12 and 13 via the conductive film 14 or directly.
[0070]
In addition, the conductive film (carbon film) 15 formed by the activation process is arranged to face each other with a first gap 17 as shown in FIG. In the drawing, the carbon film 15 is shown as being completely separated on the left and right sides with the first gap 17 as a boundary. Therefore, the carbon film 15 formed by performing the activation step can be referred to as a pair of carbon films (conductive members) 15 facing each other with a gap 17 therebetween, or a carbon film having a gap 17 (conductive). Sexual member) 15.
[0071]
Examples of carbon compounds (organic substances) used in the atmosphere for the activation step include alkanes, alkenes, alkyne aliphatic hydrocarbons, aromatic hydrocarbons, alcohols, aldehydes, ketones, amines, phenols, Examples thereof include organic acids such as carboxylic acid and sulfonic acid. Specifically, methane, ethane, propane and the like C_nH_{2n + 2}Saturated hydrocarbon, ethylene, propylene, etc. represented by C_nH_2nUnsaturated hydrocarbons represented by the composition formulas such as benzene, toluene, methanol, ethanol, formaldehyde, acetaldehyde, acetone, methyl ethyl ketone, methylamine, ethylamine, phenol, formic acid, acetic acid, propionic acid, or a mixture thereof can be used. .
[0072]
In the conventional activation process, the carbon compound (organic substance) present in the atmosphere is decomposed only by the current flowing through the second gap 16, and the carbon or the carbon compound is converted into the substrate in the second gap 16. Electrons deposited on and in the vicinity of the conductive film 14 and emitted from the vicinity of the gap 16 (the gap 17 in the middle of formation) are irradiated to the carbon or the carbon compound, so that a part of the electrons is crystallized. I think that it will become conductive.
[0073]
The crystal structure of the carbon film (conductive film) 15 obtained by the activation process includes a graphite structure and / or an amorphous structure. Further, in the process of forming the carbon film 15, there may be an intermediate structure between them. When the graphite structure is adopted, high conductivity can be obtained, but when it is an amorphous structure, the conductivity is lowered. The degree of crystallinity has a strong influence on the characteristics of the electron-emitting device, particularly on the electron emission efficiency described later.
[0074]
Here, the degree of crystallinity represents the degree of progress of a substance that can change from an amorphous state to a complete crystal structure through a state in which the periodic structure is relatively disordered.
[0075]
Further, in the conventional activation process, as the process proceeds, carbon and carbon compounds deposited in the gap 16 tend to deposit more particularly in the narrower intervals. As a result, “disturbance” occurs in the form of the formed carbon film 15.
[0076]
Therefore, in the conventional manufacturing method, “disturbance” occurs in the form of the carbon film 15 with the progress of the activation process, and there is a portion where electrons emitted from the vicinity of the gap 16 are not sufficiently irradiated to the deposited carbon or carbon compound. End up. In such a state, the carbon or carbon compound deposited in the vicinity of the gap 16 grows in a state including many regions with low crystallinity, and the resulting carbon film 15 has low conductivity. That is, this is considered to be a result brought about by insufficient electron beam irradiation in the growth process of the carbon film 15.
[0077]
When the carbon film including many regions with low crystallinity as described above is formed, collision of electrons emitted from the electron emission portion or device current I_fIt is conceivable that the crystal structure of the carbon film 15 gradually changes due to the heat generated by the above, and changes the degree of crystallization from the amorphous structure to the graphite structure. At the same time, it is considered that the resistance of the carbon film 15 changes and the electric conduction characteristics of the element gradually change.
[0078]
As a result, particularly when it is desired that the characteristics of a large number of elements such as an image forming apparatus are matched, the electron emission characteristics of the elements are changed, leading to variations in luminance.
[0079]
On the other hand, according to the method for manufacturing an electron-emitting device of the present invention, the carbon film being formed on the conductive film 14 and in the second gap 16 is irradiated to irradiate the electron beam from the outside of the device. Sufficient electron beams can be given. Therefore, a change in the physical properties of the carbon film can be promoted, and a conductive film mainly composed of a highly conductive carbon film whose crystallinity is sufficiently promoted can be efficiently formed. As a result, changes in the physical properties of the conductive film (carbon film) during driving can be suppressed. Therefore, the electron emission characteristics of the device are stabilized.
[0080]
Therefore, according to the manufacturing method of the present invention, the specific resistance of the conductive film (carbon film) 15 containing carbon as a main component can be 0.001 Ωm or less.
[0081]
In the method of manufacturing an electron source according to the present invention, an electron beam emitted from an electron emission portion of an adjacent electron emission element can be used as an electron beam irradiated to the vicinity of the gap 16. According to this method, as shown in FIG. 4, it is not necessary to separately provide electron emission means for electron beam irradiation.
[0082]
In addition, when the carbon film formation reaction occurs non-uniformly due to the “disturbance” of the form described above, the carbon 15 may be partially thickly formed, and there is a shadow region that is difficult to be irradiated with electrons. Although it may occur, it is possible to irradiate an electron beam from a different angle by receiving electrons from other adjacent elements in the same manner as the electron beam irradiation means provided outside the device. It becomes like this.
[0083]
A method using electron beams emitted from different electron-emitting devices will be described below.
[0084]
A configuration in which two elements are adjacent to each other by sharing one element electrode will be described as an example.
[0085]
In two adjacent electron-emitting devices, an electron beam emitted from one electron-emitting portion is irradiated to the vicinity of the other electron-emitting portion, so that the electron-emitting portion is irradiated with the electron beam, and carbon is a main component. A carbon film (conductive film) can be formed. At this time, electrons are emitted from the cathode side toward the anode side, so that the electrons can efficiently reach the mutual electron emission portions by aligning the directions of the electrons emitted from the respective elements. In particular, it is possible to irradiate an electron beam alternately by adopting a configuration in which the two adjacent electron-emitting devices share one device electrode or a configuration in which one device electrode is electrically connected. it can. In other words, electrons are completely emitted by applying a common device electrode or a device electrode connected to each other to the ground potential, and applying an alternating voltage with a phase shift to each electrode pair, for example, a voltage with a phase shift of π. Therefore, the irradiation of the electron beam from one electron emitting portion to the vicinity of the other electron emitting portion is alternately performed. As a result, a conductive film (carbon film) containing carbon as a main component can be efficiently formed on the two electron emission portions almost simultaneously.
[0086]
7A and 7B are schematic views showing the configuration of the electron source of the present embodiment. FIG. 7A is a plan view and FIG. 7B is a cross-sectional view. In FIG. 7, reference numeral 71 denotes a substrate, on which a common element electrode 72 and element electrodes 73 and 74 are formed. An electroconductive film 75, an electron emission portion 79, and a carbon film 76 are formed between an element electrode pair (referred to as an electrode pair A) composed of the common element electrode 72 and the element electrode 73, and the electron emission element A is configured. . Further, a conductive film 77, an electron emission portion 80, and a carbon film 78 are formed between an electrode pair (element electrode pair B) composed of the common element electrode 72 and the element electrode 74, and the electron emission element B is configured. ing.
[0087]
The basic configuration can be regarded as a single element configured by arranging elements similar to the electron-emitting elements described in FIG. 1 in series via the common element electrode 72.
[0088]
Regarding the electron-emitting device, the method for forming the electrodes 72 to 74 and the conductive films 75 and 77 is the same as the method for forming the electron-emitting device described above. Further, the electrode interval L1, the electrode length W, and the film thickness are determined in consideration of the resistance value of the electrode and the electron emission characteristics. Here, the distance L1 between the two electrode pairs is the same, and the three electrode lengths are the same. The width L2 of the common element electrode 72 is set in consideration of the distance that the electron beam emitted from one of the electron emitting portions can reach the adjacent electron emitting portion. Here, the overlap width between the element electrode and the conductive film is arbitrary as long as it is conductive.
[0089]
As a method of forming the electron emission portions 79 and 80, the common element electrode 72 is grounded, the element electrode 73 and the element electrode 74 are coupled to be equipotential, and voltage is simultaneously applied to the electrode pair A and the electrode pair B. What is necessary is just to form an electron emission part simultaneously.
[0090]
When the activation process according to the present invention is applied to two adjacent electron-emitting devices configured as shown in FIG. 7, electron beams can be irradiated from one to the other. The specific procedure will be described below.
[0091]
The common element electrode 72 is grounded, and a pulse voltage source (not shown) is connected to the element electrode 73 and the element electrode 74.
[0092]
FIG. 8 is an example of voltage waveforms (a) and (b) applied to the device electrode 73 and the device electrode 74, respectively, and a rectangular wave pulse is applied with a sign in an alternating manner. As can be seen from FIG. 8, a pulse voltage having a phase difference of π is applied to each electrode.
[0093]
By the way, electrons flow from the electrode side having a relatively low potential to the electrode side having a high potential through the electron emission portion, and a part of the electrons are emitted as an electron beam in the same direction. Therefore, when a voltage as shown in FIG. 8 is applied, the electron beam is emitted alternately in the direction of the electron emission portions 79 to 80 and in the direction of 80 to 79.
[0094]
This is schematically shown in FIG. Each time the polarity of the pulse voltage changes, the direction in which the electron beam is emitted changes as shown in FIGS. 9A and 9B. In the case of FIG. 9A, the electron beam emitted from the electron emission portion 79 is irradiated near the electron emission portion 80. In the case of FIG. 9B, the electron beam emitted from the electron emission portion 80 is irradiated near the electron emission portion 79.
[0095]
Alternatively, a voltage waveform as shown in FIG. 10 can be used as another pulse pattern. In this case, pulse voltages having phases different from each other by π / 2 are applied to the device electrode 73 and the device electrode 74. By using this waveform pattern, when an electron beam is emitted from one electron emitting portion, no electron beam is emitted from the other electron emitting portion, so that an electron beam from one direction can be received, Interference when the electron beam is irradiated from the direction can be eliminated.
[0096]
Furthermore, according to the present invention, variation in characteristics between elements due to meandering of the second gap 16 by the forming process described above can be reduced by the manufacturing method described below.
[0097]
That is, in another embodiment of the present invention, the above-described present invention is directly applied between a pair of element electrodes (conductive members) 12 and 13 having relatively excellent linearity without using the conductive film 14 described above. The activation step is performed. FIG. 21A is a schematic plan view of the electron-emitting device of this embodiment, and FIG. 21B is a schematic cross-sectional view thereof. 22 and 23 are schematic views showing a part of the process of the manufacturing method. In the schematic diagram shown in FIG. 21, the first gap 17 is shown as a perfect straight line, but this is shown for easier understanding of the present invention. In FIG. 21, the carbon film 15 is shown as being completely separated with the first gap 17 as a boundary, but may be connected at a part thereof. Therefore, the carbon film 15 formed by performing the activation step can be referred to as a pair of carbon films (conductive members) 15 facing each other with a gap 17 therebetween, or a carbon film having a gap 17 (conductive). Sexual member) 15.
[0098]
In another manufacturing method of the present invention, first, a pair of element electrodes (conductive members) 12 and 13 are arranged with a gap L on the substrate 11 (FIG. 22A). In this embodiment, the gap between the device electrodes 12 and 13 corresponds to the first gap 16 described above.
[0099]
Next, the activation process of the present invention is performed. In this activation step, an electron emission means is separately provided, and an electron beam emitted from the electron emission means is irradiated between the electrodes 12 and 13 while irradiating one of the following areas (1) and (2). A voltage is applied to form the carbon film 15 (FIGS. 22B and 23). That is, a voltage is applied between the electrodes 12 and 13 simultaneously with the electron beam irradiation from the electron emitting means.
[0100]
As the irradiation region of the electron beam,
(1) A substrate 11 between the device electrodes 12, 13;
(2) The base 11 between the element electrodes 12 and 13, and the electrodes 12 and 13,
One of them.
[0101]
As a result, the carbon film 15 can be formed on the device electrodes 12 and 13 and the insulating substrate 11 between the device electrodes, and at the same time, the first gap 17 can be formed between the device electrodes 12 and 13.
[0102]
FIG. 23 is a diagram schematically showing an apparatus for irradiating an electron beam from the outside. The configuration of the electron beam irradiation apparatus shown in FIG. 23 is basically the same as that shown in FIG. In FIG. 23, 61 is an electron emission means. The electron-emitting device and the electron-emitting means 61 may be installed in the same vacuum container, but if necessary, the electron-emitting device and the electron-emitting means 61 are installed in a different vacuum container from the vacuum container in which the substrate 11 is installed. May be.
[0103]
When differential pumping is performed, a pinhole for electron beam transmission (62 in FIG. 23) is applied, and since the conductance of the pinhole is low, the pressure inside the vacuum vessel in which the substrate 11 is installed and the electron emission means It becomes possible to isolate | separate the pressure in the vacuum vessel in which 61 was installed.
[0104]
The electron emission means 61 may be a structure that uses a hot cathode as an electron beam source and accelerates by applying an acceleration voltage. Further, in order to finely control the electron beam irradiation region, an electron beam blocking means 63 may be provided.
[0105]
In the electron beam irradiation, the device electrodes 12 and 13 and / or the substrate 11 between the device electrodes may be irradiated in a DC manner, or may be pulsed in synchronization with a pulse voltage applied to the electrodes.
[0106]
As described above, in the present embodiment, the conductive film 14 electrically connected to the element electrode and the second gap 16 are formed in the conductive film, which are necessary in the activation process. Energization forming becomes unnecessary.
[0107]
That is, by irradiating an electron beam from the outside, the carbon film 15 and the first gap 17 are arranged directly at an electrode interval L (several μm to several tens μm) that is much wider than the width of the second gap 16. can do. In the element having the configuration shown in FIG. 21, the second gap 16 described above corresponds to the distance between the electrodes 12 and 13. Therefore, in the element of this embodiment, the second gap can be formed with high linearity and high uniformity of the width (L).
[0108]
Therefore, in the element shown in FIG. 19 or FIG. 20, the above-described non-uniformity of the distance between the second gaps 16 and the non-uniformity of the distance from the end of the element electrodes 12, 13 to the second gap 16 (see FIG. ), Local variations in emission characteristics in the electron-emitting device are reduced. Furthermore, due to the above-described effects of electron beam irradiation, the electron emission efficiency of the device can be improved, and fluctuations and deterioration of characteristics during driving of the device can be greatly reduced.
[0109]
In addition, according to the present embodiment, the conductive film 14 electrically connected to the element electrode, which is required in the conventional activation process, and the second gap 16 for forming the second gap 16 in the conductive film are used. Since energization forming is not required, the element configuration is simplified and the number of processes can be reduced. That is, an electron-emitting device having stable and highly efficient electron-emitting characteristics can be manufactured efficiently and inexpensively. Further, in an electron source and an image forming apparatus in which a plurality of the electron-emitting devices are arranged on the same substrate, an electron source and an image forming apparatus having high uniformity, high efficiency and stable characteristics can be obtained.
[0110]
In the activation process of the present invention described above, it is particularly preferable to apply a voltage between the device electrodes 12 and 13 while irradiating the electron beam from the electron emission means 41 (61). That is, it is preferable to irradiate the electron beam from the electron emission means during the period in which the voltage is applied between the device electrodes 12 and 13. According to this method, the crystallinity of the initial deposition of carbon and / or carbon compound forming the first gap 17 can be made higher. That is, in comparison with the conventional activation method, high energy electrons irradiated from the electron emission means 41 (61) are separately irradiated, so that the current flowing between the device electrodes 12 and 13 (the second gap 16 or the formation). Carbon and / or carbon compounds deposited by electrons emitted from the vicinity of the first gap 17 on the way can be formed as a carbon film having a high degree of crystallinity from the beginning of the deposition. Therefore, for example, the width of the gap 17 can be formed narrower, and it can be expected to form an element having excellent characteristics.
[0111]
(Process E)
The electron-emitting device obtained through the activation process of the present invention is preferably subjected to a stabilization process. This step is a step of exhausting the organic substance in the vacuum vessel. As the vacuum exhaust device for exhausting the vacuum vessel, it is preferable to use a 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 apparatus such as a sorption pump or an ion pump can be used.
[0112]
When an oil diffusion pump or a rotary pump is used as an exhaust device in the activation step and an organic gas derived from an oil component to be generated is used, it is necessary to keep the partial pressure of this component as low as possible. The partial pressure of the organic component in the vacuum vessel is 1 × 10 with a partial pressure at which the carbon or the carbon compound is not newly deposited.^-6Pa or less is preferable, and further 1 × 10^-8Pa or less is particularly preferable. Furthermore, when evacuating the inside of the vacuum container, it is preferable to heat the entire vacuum container so that the organic substance molecules adsorbed on the inner wall of the vacuum container and the electron-emitting device can be easily exhausted. The heating condition at this time is 80 to 300 ° C., preferably 150 ° C. or higher, and it is desirable to perform the treatment for as long as possible. However, it is not particularly limited to this condition, and the size and shape of the vacuum vessel, the configuration of the electron-emitting device The conditions are appropriately selected according to various conditions such as the above. The pressure in the vacuum vessel needs to be as low as possible, 1 × 10^-5Pa or less is preferable, and further 1 × 10^-6Pa or less is particularly preferable.
[0113]
The driving atmosphere after the stabilization process is preferably maintained at the end of the stabilization process, but is not limited to this, and the pressure itself is sufficient if the organic substance is sufficiently removed. Can maintain sufficiently stable characteristics even if it rises somewhat. By adopting such a vacuum atmosphere, deposition of new carbon or carbon compounds can be suppressed, and as a result, the device current I_f, Emission current I_eIs stable.
[0114]
Next, basic characteristics of the electron-emitting device of the present invention will be described. FIG. 5 is a schematic diagram of the evaluation apparatus. This evaluation apparatus has a function as a vacuum apparatus and an element characteristic measuring apparatus. 5, the same parts as those shown in FIG. 1 are denoted by the same reference numerals as those shown in FIG. 1. That is, 11 is a substrate constituting the electron-emitting device, 12 and 13 are electrodes, 14 is a conductive film, and 100 is an electron-emitting portion. For convenience, the conductive coating 15 is omitted. Reference numeral 51 denotes an element voltage V applied to the electron-emitting device._f50 is a device current I flowing through the conductive film 14 between the electrodes 12 and 13._f54 is an emission current I emitted from the electron emission portion of the device._eIt is an anode electrode for capturing. Reference numeral 53 denotes a high voltage power source for applying a voltage to the anode electrode 54, and reference numeral 52 denotes an emission current I emitted from the electron emission portion 16 of the device._eIt is an ammeter for measuring. In the present invention, the measurement was performed by setting the voltage of the anode electrode to 1 kV and the distance H between the anode electrode and the electron-emitting device to 2 mm.
[0115]
In the measurement, first, in order to suppress the deposition of new carbon or carbon compound, the organic material in the vacuum vessel is exhausted, and the vacuum exhaust device 56 that exhausts the vacuum vessel 55 contains oil generated from the device. In order not to affect the characteristics, a vacuum exhaust device that does not use oil, such as a sorption pump, is used.
[0116]
The partial pressure of the organic component in the vacuum vessel 55 is 1 × 10 with a partial pressure at which the above carbon and carbon compounds are hardly deposited.^-8Pa or less. At this time, it is preferable to heat the entire vacuum vessel to 200 ° C. or higher so that the organic substance molecules adsorbed on the inner wall of the vacuum vessel and the electron-emitting device are easily exhausted.
[0117]
6 shows the emission current I of the electron-emitting device of the present invention measured using the evaluation apparatus of FIG._e, Element current I_fAnd element voltage V_fIt is the figure which showed this relationship typically. In FIG. 6, the emission current I_eIs the device current I_fSince it is remarkably small compared to, it is shown in arbitrary units. The vertical and horizontal axes are linear scales.
[0118]
As is clear from FIG. 6, the electron-emitting device of the present invention has an emission current I._eHas the following three characteristic properties.
[0119]
First, the device has a certain voltage (referred to as a threshold voltage; V in FIG._th) When the above device voltage is applied, the emission current I suddenly increases._eWhile the threshold voltage V_thIn the following, the emission current I_eIs hardly detected. That is, the emission current I_eClear threshold voltage V for_thIs a non-linear element.
[0120]
Second, the emission current I_eIs the element voltage V_fThe emission current I_eIs the element voltage V_fCan be controlled.
[0121]
Third, the emitted charge trapped by the anode electrode 54 (see FIG. 5) is the device voltage V_fDepends on the time to apply. That is, the amount of charge trapped by the anode electrode 54 is the element voltage V_fCan be controlled by applying time.
[0122]
As can be understood from the above description, the electron-emitting device of the present invention can easily control the electron-emitting 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 configured by arranging a plurality of electron-emitting devices.
[0123]
In FIG. 6, the element current I_fElement voltage V_fIn this example, the element current I increases monotonically (MI characteristic)._fIs the element voltage V_fMay exhibit voltage controlled negative resistance characteristics (VCNR characteristics) (not shown). These characteristics can be controlled by controlling the aforementioned steps.
[0124]
Due to the characteristic characteristics of the electron-emitting device of the present invention as described above, an electron source having a plurality of electron-emitting devices can easily control the amount of emitted electrons according to an input signal even in an image forming apparatus or the like. Therefore, it can be applied to various fields.
[0125]
An application example of the electron-emitting device of the present invention will be described below. By arranging a plurality of electron-emitting devices of the present invention on a substrate, for example, an electron source and further an image forming apparatus can be configured.
[0126]
Various arrangements of the electron-emitting devices can be employed. As an example, a large number of electron-emitting devices arranged in parallel are connected at both ends, a plurality of rows of electron-emitting devices are arranged (row direction), and the electron emission is performed in a direction perpendicular to the wiring (column direction). There is a ladder-type arrangement in which electrons from the electron-emitting device are controlled and driven by a control electrode (grid electrode) disposed above the device. Separately, a plurality of electron-emitting devices are arranged in a matrix in the X and Y directions, and one of the electrodes of the plurality of electron-emitting devices arranged in the same row is connected in common to the X-direction wiring. One that commonly connects the other electrode of the plurality of electron-emitting devices arranged in a row to the wiring in the Y-direction. Such an arrangement is a so-called simple matrix arrangement. First, the simple matrix arrangement will be described in detail below.
[0127]
As described above, the electron-emitting device of the present invention has three characteristics. In other words, the emitted electrons from the electron-emitting device can be controlled by the peak value and width of the pulse voltage applied between the device electrodes facing each other above the threshold voltage. On the other hand, almost no electrons are emitted below the threshold voltage. According to this characteristic, even when a large number of electron-emitting devices are arranged, the amount of electron emission can be controlled by selecting the electron-emitting device according to the input signal if a pulse voltage is appropriately applied to each device. .
[0128]
Hereinafter, based on this principle, an electron source substrate obtained by arranging a plurality of surface conduction electron-emitting devices as an embodiment of the electron-emitting device of the present invention will be described with reference to FIG. In FIG. 12, 121 is an electron source substrate, 122 is an X direction wiring, and 123 is a Y direction wiring. 124 is a surface conduction electron-emitting device, and 125 is a connection.
[0129]
The m X-direction wirings 122 are D_x1, D_x2... D_xmAnd can be made of a conductive metal or the like formed using a vacuum deposition method, a printing method, a sputtering method, or the like. The wiring material, film thickness, and width are appropriately designed. Y direction wiring 123 is D_y1, D_y2... D_ynThe n wirings are formed in the same manner as the X direction wiring 122. An interlayer insulating layer (not shown) is provided between the m X-direction wirings 122 and the n Y-direction wirings 123 to electrically isolate them (m and n are both positive and negative). Integer).
[0130]
The interlayer insulating layer (not shown) is formed of SiO formed by vacuum deposition, printing, sputtering, or the like.₂Etc. For example, it is formed in a desired shape on the entire surface or a part of the substrate 121 on which the X-direction wiring 122 is formed. The manufacturing method is appropriately set. The X-direction wiring 122 and the Y-direction wiring 123 are drawn out as external terminals, respectively.
[0131]
A pair of device electrodes (not shown) constituting the electron-emitting device 124 are electrically connected to the m X-direction wirings 122 and the n Y-direction wirings 123 by connection lines 125 made of conductive metal or the like. Yes.
[0132]
The material constituting the X-direction wiring 122 and the Y-direction wiring 123, the material constituting the connection 125, and the material constituting the pair of element electrodes may be the same even if some or all of the constituent elements are the same. It may be different. These materials are appropriately selected from, for example, the above-described element electrode materials. When the material constituting the element electrode is the same as the wiring material, it can be said that the wiring connected to the element electrode is the element electrode.
[0133]
The X direction wiring 122 is connected to scanning signal applying means (not shown) for applying a scanning signal for selecting a row of the electron-emitting devices 124 arranged in the X direction. On the other hand, the Y direction wiring 123 is connected to a modulation signal generating means (not shown) for modulating each column of the electron-emitting devices 124 arranged in the Y direction according to an input signal. The drive voltage applied to each electron-emitting device is supplied as a difference voltage between the scanning signal and the modulation signal applied to the device.
[0134]
In the above configuration, individual elements can be selected and driven independently using a simple matrix wiring.
[0135]
An image forming apparatus configured using an electron source having such a simple matrix arrangement will be described with reference to FIGS. 13, 14, and 15. FIG. 13 is a schematic view showing an example of a display panel of the image forming apparatus, and FIG. 14 is a schematic view of a fluorescent film used in the image forming apparatus of FIG. FIG. 15 is a block diagram showing an example of a drive circuit for performing display in accordance with NTSC television signals. In addition, the same code | symbol is attached | subjected to the site | part same as the site | part shown in FIG. 12, and description is abbreviate | omitted. For convenience, the conductive film 14 and the conductive film 15 are omitted.
[0136]
In FIG. 13, 131 is a rear plate to which the electron source substrate 121 is fixed, and 136 is a face plate in which a fluorescent film 134, a metal back 135 and the like are formed on the inner surface of a glass substrate 133. Reference numeral 132 denotes a support frame, and a rear plate 131 and a face plate 136 are connected to the support frame 132 using frit glass or the like. Reference numeral 138 denotes an envelope, which is configured to be sealed by baking for 10 minutes or more in a temperature range of 400 to 500 ° C., for example.
[0137]
As described above, the envelope 138 includes the face plate 136, the support frame 132, and the rear plate 131. Since the rear plate 131 is provided mainly for the purpose of reinforcing the strength of the electron source substrate 121, the separate rear plate 131 is not necessary when the substrate 121 itself has sufficient strength. That is, the support frame 132 may be directly sealed on the substrate 121, and the envelope 138 may be configured by the face plate 136, the support frame 132, and the substrate 121. On the other hand, by installing a support member (not shown) called a spacer between the face plate 136 and the rear plate 131, the envelope 138 having sufficient strength against atmospheric pressure can be configured.
[0138]
FIG. 14 is a schematic diagram showing a fluorescent film. In the case of monochrome, the fluorescent film 134 can be composed of only a phosphor. In the case of a color fluorescent film, it is composed of a black conductive material 141 called a black stripe (FIG. 14 (b)) or a black matrix (FIG. 14 (b)) and a phosphor 142 depending on the arrangement of the phosphors. Can do. The purpose of providing the black stripe and the black matrix is to make the mixed colors and the like inconspicuous by blackening the required color separation portion between the three primary color phosphors 142 in the case of color display, and contrast by reflection of external light on the fluorescent film 134 It is in suppressing the fall of the. As a material of the black conductive material 141, a material having conductivity and low light transmission and reflection can be used in addition to a commonly used material mainly composed of graphite.
[0139]
As a method of applying the phosphor on the glass substrate 133, a precipitation method, a printing method, or the like can be adopted regardless of monochrome or color. A metal back 135 is usually provided on the inner surface side of the fluorescent film 134. The purpose of providing the metal back is to improve the brightness by specularly reflecting the light emitted from the phosphor to the inner surface side to the glass substrate 133 side, to act as an electrode for applying an electron beam acceleration voltage, For example, the phosphor is protected from damage caused by the collision of negative ions generated in the envelope. The metal back can be produced by performing a smoothing process (usually called “filming”) on the inner surface of the phosphor film after the phosphor film is produced, and then depositing Al using vacuum evaporation or the like.
[0140]
Further, the face plate 136 may be provided with a transparent electrode (not shown) on the outer surface side of the fluorescent film 134 in order to further increase the conductivity of the fluorescent film 134.
[0141]
When performing the above-described sealing, in the case of a color, it is necessary to associate each color phosphor with the electron-emitting device, and sufficient alignment is essential.
[0142]
The image forming apparatus shown in FIG. 13 is manufactured, for example, as follows.
[0143]
The inside of the envelope 138 is exhausted through an exhaust pipe (not shown) by an exhaust device that does not use oil, such as an ion pump or a sorption pump, while being appropriately heated, as in the above-described stabilization step.^-5Sealing is performed after the atmosphere is sufficiently low in an organic material having a degree of vacuum of about Pa. In order to maintain the degree of vacuum after the envelope 138 is sealed, a getter process may be performed. This is because a getter (not shown) arranged at a predetermined position in the envelope 138 is heated by heating using resistance heating or high-frequency heating immediately before or after sealing the envelope 138. And a process for forming a deposited film. The getter is usually composed mainly of Ba or the like, and, for example, 1 × 10 6 by the adsorption action of the deposited film^-5A degree of vacuum of Pa or higher is maintained.
[0144]
Next, a configuration example of a driving circuit for performing television display based on an NTSC television signal on a display panel configured using an electron source having a simple matrix arrangement will be described with reference to FIG. In FIG. 15, 151 is a display panel, 152 is a scanning circuit, 153 is a control circuit, 154 is a shift register, 155 is a line memory, 156 is a synchronizing signal separation circuit, 157 is a modulation signal generator, and Vx and Va are DC voltage sources. It is.
[0145]
The display panel 151 has a terminal D_x1~ D_xm, Terminal D_y1~ D_ynAnd an external electric circuit through a high voltage terminal 137. Terminal D_x1~ D_xmA scanning signal for sequentially driving one row (n elements) of an electron source provided in the display panel 151, that is, a group of electron emitting elements arranged in a matrix of m rows and n columns, is applied. Terminal D_y1~ D_ynIs applied with a modulation signal for controlling the output electron beam of each element of one row of electron-emitting elements selected by the scanning signal. The high-voltage terminal 137 is supplied with a DC voltage of, for example, 10 kV from the DC voltage source Va, and this imparts sufficient energy to excite the phosphor to the electron beam emitted from the electron-emitting device. Accelerating voltage.
[0146]
Next, the scanning circuit 152 will be described. The circuit includes m switching elements (in FIG. 15, S₁~ S_m(Schematically). Each switching element selects either the output voltage of the DC voltage source Vx or 0 [V] (ground level), and the terminal D of the display panel 151 is selected._x1~ D_xmAnd electrically connected. Each switching element S₁~ S_mIs a control signal T output from the control circuit 153._scanFor example, it can be configured by combining switching elements such as FETs.
[0147]
The DC voltage source Vx outputs a constant voltage based on the characteristics (electron emission threshold voltage) of the electron-emitting device so that the drive voltage applied to the non-scanned device is equal to or lower than the electron-emitting threshold voltage. Is set to
[0148]
The control circuit 153 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 153 receives the synchronization signal T sent from the synchronization signal separation circuit 156._syncT for each part based on_scan, T_sftAnd T_mryEach control signal is generated.
[0149]
The synchronization signal separation circuit 156 is a circuit for separating a synchronization signal component and a luminance signal component from an NTSC television signal input from the outside, and can be configured using a general frequency separation (filter) circuit or the like. . The synchronization signal separated by the synchronization signal separation circuit 156 includes a vertical synchronization signal and a horizontal synchronization signal._syncIllustrated as a signal. The luminance signal component of the image separated from the television signal is expressed as a DATA signal for convenience. This DATA signal is input to the shift register 154.
[0150]
The shift register 154 is for serial / parallel conversion of the DATA signal serially input in time series for each line of the image, and a control signal T sent from the control circuit 153._sft(Ie, the control signal T_sftCan be paraphrased as a shift clock of the shift register 154). Data for one line of the serial / parallel converted image (corresponding to drive data for n electron-emitting devices) is I_d1~ I_dnAre output from the shift register 154 as n parallel signals.
[0151]
The line memory 155 is a storage device for storing data for one line of an image for a necessary time, and a control signal T sent from the control circuit 153._mryAccording to I_d1~ I_dnMemorize the contents of The stored content is I_{d ' 1}~ I_{d ' n}And is input to the modulation signal generator 157.
[0152]
The modulation signal generator 157 receives the image data I_{d ' 1}~ I_{d ' n}The signal source for appropriately driving and modulating each of the electron-emitting devices according to each of the output signals of the terminal D_y1~ D_ynAnd applied to the electron-emitting devices in the display panel 151.
[0153]
As described above, the electron-emitting device of the present invention has the emission current I._eHas the following basic characteristics. That is, there is a clear threshold voltage V for electron emission._thThere is V_thElectron emission occurs only when the above voltage is applied. For voltages above the electron emission threshold, the emission current also changes with changes in the voltage applied to the device. Therefore, when a pulse voltage is applied to the device, for example, even if a voltage lower than the electron emission threshold voltage is applied, no electron emission occurs, but a voltage higher than the electron emission threshold voltage is applied. In some cases, an electron beam is output. At that time, the intensity of the output electron beam can be controlled by changing the peak value Vm of the pulse. Further, it is possible to control the total amount of charges of the output electron beam by changing the pulse width Pw.
[0154]
Accordingly, a voltage modulation method, a pulse width modulation method, or the like can be adopted as a method for modulating the electron-emitting device according to the input signal. When implementing the voltage modulation method, the modulation signal generator 157 generates a voltage pulse of a certain length and can appropriately modulate the peak value of the voltage pulse according to the input data. Can be used. When implementing the pulse width modulation method, the modulation signal generator 157 generates a voltage pulse having a constant peak value and appropriately modulates the width of the voltage pulse according to the input data. A circuit can be used.
[0155]
The shift register 154 and the line memory 155 can be either 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.
[0156]
When the digital signal system is used, it is necessary to convert the output signal DATA of the synchronization signal separation circuit 156 into a digital signal. For this purpose, an A / D converter may be provided at the output portion of the synchronization signal separation circuit 156. . In this connection, the circuit used for the modulation signal generator 157 is slightly different depending on whether the output signal of the line memory 155 is a digital signal or an analog signal. That is, in the case of a voltage modulation method using a digital signal, for example, a D / A conversion circuit is used as the modulation signal generator 157, and an amplifier circuit or the like is added as necessary. In the case of the pulse width modulation method, the modulation signal generator 157 includes, for example, a high-speed oscillator and a counter that counts the wave number output from the oscillator, and a comparator that compares the output value of the counter with the output value of the memory. A circuit combining (comparators) is used. If necessary, an amplifier for amplifying the pulse width-modulated modulation signal output from the comparator to the driving voltage of the electron-emitting device can be added.
[0157]
In the case of a voltage modulation method using an analog signal, for example, an amplifier circuit using an operational amplifier or the like can be adopted as the modulation signal generator 157, and a level shift circuit or the like can be added if necessary. In the case of the pulse width modulation method, for example, a voltage controlled oscillation circuit (VCO) can be adopted, and an amplifier for amplifying the voltage up to the driving voltage of the electron-emitting device can be added if necessary.
[0158]
In the image forming apparatus of the present invention that can take such a configuration, each electron-emitting device has a container external terminal D._x1~ D_xm, D_y1~ D_ynWhen a voltage is applied via, electron emission occurs. At the same time, a high voltage is applied to the metal back 135 or the transparent electrode (not shown) via the high voltage terminal 137 to accelerate the electron beam. The accelerated electrons collide with the fluorescent film 134 and light emission is generated to form an image.
[0159]
The configuration of the image forming apparatus described here is an example of the image forming apparatus of the present invention, and various modifications can be made based on the technical idea of the present invention. Although the NTSC system has been mentioned as the input signal, the input signal is not limited to this, and in addition to the PAL, SECAM system, etc., television signals (for example, the MUSE system, etc.) including a larger number of scanning lines than these. High-definition TV) system can also be adopted.
[0160]
Next, the ladder-arranged electron source and the image forming apparatus will be described with reference to FIGS.
[0161]
FIG. 16 is a schematic diagram showing an example of an electron source arranged in a ladder shape. In FIG. 16, 160 is an electron source substrate, and 161 is an electron-emitting device. 162 is a common wiring D for connecting the electron-emitting device 161.₁~ D₁₀These are drawn out as external terminals. A plurality of electron-emitting devices 161 are arranged in parallel in the X direction on the substrate 160 (this is called an element row). A plurality of element rows are arranged to constitute an electron source. By applying a driving voltage between the common lines of each element row, each element row can be driven independently. That is, a voltage equal to or higher than the electron emission threshold is applied to the element row where the electron beam is to be emitted, and a voltage equal to or lower than the electron emission threshold is applied to the element row where the electron beam is not desired to be emitted. Common wiring D located between each element row₂~ D₉For example, D₂And D₃Can be integrated into the same wiring.
[0162]
FIG. 17 is a schematic diagram illustrating an example of a panel structure in an image forming apparatus including an electron source arranged in a ladder shape. 170 is a grid electrode, 171 is an opening through which electrons pass, D₁~ D_mIs the container outer terminal, G₁~ G_nIs a container external terminal connected to the grid electrode 170. Reference numeral 160 denotes an electron source substrate in which common wiring between element rows is the same wiring. In FIG. 17, the same parts as those shown in FIGS. 13 and 16 are denoted by the same reference numerals. For convenience, the conductive film 14 and the conductive film 15 are omitted. A major difference between the image forming apparatus shown here and the image forming apparatus having the simple matrix arrangement shown in FIG. 13 is whether or not the grid electrode 170 is provided between the electron source substrate 160 and the face plate 136.
[0163]
In FIG. 17, a grid electrode 170 is provided between the substrate 160 and the face plate 136. The grid electrode 170 is for modulating the electron beam emitted from the electron-emitting device 161, and passes the electron beam through stripe-shaped electrodes provided perpendicular to the element rows of the ladder-like arrangement. One circular opening 171 is provided for each element. The shape and arrangement of the grid electrodes are not limited to those shown in FIG. For example, a large number of passage openings can be provided as mesh openings, and grid electrodes can be provided around or in the vicinity of the electron-emitting devices.
[0164]
Container outer terminal D₁~ D_mAnd G₁~ G_nAre connected to a control circuit (not shown). Then, a modulation signal for one line of the image is simultaneously applied to the grid electrode columns in synchronization with the sequential driving (scanning) of the element rows one by one. Thereby, irradiation of each electron beam to the phosphor can be controlled, and an image can be displayed line by line.
[0165]
The image forming apparatus of the present invention described above can be used as an image forming apparatus as an optical printer configured using a photosensitive drum or the like, in addition to a display apparatus for television broadcasting, a display apparatus such as a video conference system or a computer. Can be used.
[0166]
FIG. 18 is a diagram showing an example of the image forming apparatus of the present invention configured to display image information provided from various image information sources such as television broadcast.
[0167]
In the figure, 1700 is a display panel, 1701 is a display panel drive circuit, 1702 is a display controller, 1703 is a multiplexer, 1704 is a decoder, 1705 is an input / output interface circuit, 1706 is a CPU, 1707 is an image generation circuit, and 1708 to 1710 are An image memory interface circuit, 1711 is an image input interface circuit, 1712 and 1713 are TV signal receiving circuits, and 1714 is an input unit.
[0168]
Note that this image forming apparatus, when receiving a signal including both video information and audio information, such as a television signal, naturally reproduces the audio simultaneously with the display of the video. A description of circuits, speakers, and the like related to reception, separation, reproduction, processing, storage, and the like of audio information not directly related to features will be omitted.
[0169]
Hereinafter, the function of each unit will be described along the flow of the image signal.
[0170]
First, the TV signal receiving circuit 1713 is a circuit for receiving a TV signal transmitted using a wireless transmission system such as a radio wave or space optical communication. The system of the TV signal to be received is not particularly limited, and any system such as an NTSC system, a PAL system, or a SECAM system may be used. Further, TV signals composed of a larger number of scanning lines, for example, so-called high-definition TV signals including the MUSE system, are suitable for taking advantage of the display panel suitable for increasing the area and the number of pixels. It is a signal source.
[0171]
The TV signal received by the TV signal receiving circuit 1713 is output to the decoder 1704.
[0172]
The TV signal receiving circuit 1712 is a circuit for receiving a TV signal transmitted using a wired transmission system such as a coaxial cable or an optical fiber. Similar to the TV signal receiving circuit 1713, the method 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 1704.
[0173]
The image input interface circuit 1711 is a circuit for capturing an image signal supplied from an image input device such as a TV camera or an image reading scanner, and the captured image signal is output to the decoder 1704.
[0174]
The image memory interface circuit 1710 is a circuit for capturing an image signal stored in a video tape recorder (hereinafter referred to as “VTR”), and the captured image signal is output to the decoder 1704.
[0175]
The image memory interface circuit 1709 is a circuit for capturing an image signal stored in the video disk, and the captured image signal is output to the decoder 1704.
[0176]
The image memory interface circuit 1708 is a circuit for capturing an image signal from a device storing still image data, such as a still image disc. The captured still image data is input to the decoder 1704.
[0177]
The input / output interface circuit 1705 is a circuit for connecting the image display apparatus and an output apparatus such as an external computer, a computer network, or a printer. It is also possible to input / output image data, character / graphic information, and in some cases, input / output control signals and numerical data between the CPU 1706 of the image forming apparatus and the outside.
[0178]
The image generation circuit 1707 generates display image data based on image data or character / graphic information input from the outside via the input / output interface circuit 1705 or image data or character / graphic information output from the CPU 1706. It is a circuit for generating. Inside this circuit, for example, a rewritable memory for storing image data, character / graphic information, a read-only memory in which an image pattern corresponding to a character code is stored, a processor for performing image processing, etc. And other circuits necessary for image generation are incorporated.
[0179]
Display image data generated by this circuit is output to the decoder 1704, but in some cases, it can also be output to an external computer network or printer via the input / output interface circuit 1705.
[0180]
The CPU 1706 mainly performs operations related to operation control of the image display apparatus, generation, selection, and editing of display images.
[0181]
For example, a control signal is output to the multiplexer 1703, and image signals to be displayed on the display panel are appropriately selected or combined. In this case, a control signal is generated for the display panel controller 1702 in accordance with the image signal to be displayed, and the display device such as the screen display frequency, the scanning method (for example, interlaced or non-interlaced), the number of scanning lines in one screen, etc. The operation is appropriately controlled. In addition, image data, character / graphic information is directly output to the image generation circuit 1707, or an external computer or memory is accessed via the input / output interface circuit 1705 to obtain image data, character / graphic information. input.
[0182]
Note that the CPU 1706 may be involved in work for other purposes. For example, it may be directly related to a function for generating or processing information, such as a personal computer or a word processor. Alternatively, as described above, it may be connected to an external computer network via the input / output interface circuit 1705, and for example, operations such as numerical calculation may be performed jointly as an external device.
[0183]
The input unit 1714 is used by a user to input commands, programs, data, and the like to the CPU 1706. For example, in addition to a keyboard and a mouse, various input devices such as a joystick, a barcode reader, and a voice recognition device can be used. It is possible to use.
[0184]
The decoder 1704 is a circuit for inversely converting the various image signals input from 1707 to 1713 into three primary color signals, or luminance signals, I signals, and Q signals. As indicated by the dotted line in the figure, the decoder 1704 preferably includes an image memory therein. This is because, for example, a MUSE system and other television signals that require an image memory for reverse conversion are handled. In addition, the provision of the image memory facilitates the display of still images. Alternatively, in cooperation with the image generation circuit 1707 and the CPU 1706, there is an advantage that image processing and editing including image thinning, complementing, enlargement, reduction, and composition are facilitated.
[0185]
The multiplexer 1703 appropriately selects a display image based on a control signal input from the CPU 1706. That is, the multiplexer 1703 selects a desired image signal from the inversely converted image signals input from the decoder 1704 and outputs the selected image signal to the drive circuit 1701. In that case, by switching and selecting an image signal within one screen display time, it is possible to divide one screen into a plurality of regions and display different images depending on the region, as in a so-called multi-screen television. .
[0186]
The display panel controller 1702 is a circuit for controlling the operation of the drive circuit 1701 based on a control signal input from the CPU 1706.
[0187]
As for the basic operation of the display panel, for example, a signal for controlling an operation sequence of a driving power source (not shown) for the display panel is output to the driving circuit 1701. For example, a signal for controlling a screen display frequency and a scanning method (for example, interlace or non-interlace) is output to the drive circuit 1701 as a display panel drive method. In some cases, a control signal related to image quality adjustment such as brightness, contrast, color tone, and sharpness of a display image may be output to the drive circuit 1701.
[0188]
The drive circuit 1701 is a circuit for generating a drive signal to be applied to the display panel 1700, and operates based on an image signal input from the multiplexer 1703 and a control signal input from the display panel controller 1702. It is.
[0189]
The function of each unit has been described above. With the configuration illustrated in FIG. 18, the image forming apparatus can display image information input from various image information sources on the display panel 1700. That is, various image signals including television broadcasts are inversely converted by the decoder 1704, then appropriately selected by the multiplexer 1703, and input to the drive circuit 1701. On the other hand, the display controller 1702 generates a control signal for controlling the operation of the drive circuit 1701 in accordance with the image signal to be displayed. The drive circuit 1701 applies a drive signal to the display panel 1700 based on the image signal and the control signal. As a result, an image is displayed on the display panel 1700. A series of these operations is centrally controlled by the CPU 1706.
[0190]
In the present image forming apparatus, not only the image memory incorporated in the decoder 1704, the image generation circuit 1707 and the information selected from the information are displayed, but also the displayed image information is enlarged, reduced, rotated, for example. Image processing such as movement, edge enhancement, thinning, interpolation, color conversion, image aspect ratio conversion, etc., and image editing such as composition, deletion, connection, replacement, and fitting are also possible. . Similarly to the image processing and image editing described above, a dedicated circuit for processing and editing audio information may be provided.
[0191]
Therefore, the image forming apparatus includes a television broadcast display device, a video conference terminal device, an image editing device that handles still images and moving images, a computer terminal device, an office terminal device such as a word processor, a game machine, and the like. These functions can be combined in a single unit, and the range of applications is extremely wide for industrial use or consumer use.
[0192]
FIG. 18 only shows an example of the configuration in the case of an image forming apparatus using a display panel using an electron-emitting device as an electron beam source, and the image forming apparatus of the present invention is limited to this. It goes without saying that it is not a thing.
[0193]
For example, among the components shown in FIG. 18, circuits relating to functions that are not necessary for the purpose of use may be omitted. On the contrary, depending on the purpose of use, further components may be added. For example, when the present image display device is applied as a video phone, it is preferable to add a transmission / reception circuit including a TV camera, an audio microphone, an illuminator, and a modem to the constituent elements.
[0194]
In this image forming apparatus, since the electron-emitting device is used as an electron source, it is easy to make the display panel thin, so that the depth of the image forming apparatus can be reduced. In addition, a display panel that uses an electron-emitting device as an electron beam source can easily make a large screen, has high brightness, and has excellent viewing angle characteristics. It is possible to display with high visibility.
[0195]
【Example】
Example 1
As Example 1 of the present invention, an electron-emitting device having the configuration shown in FIG. 1 was produced. A present Example is described using FIG. 1, FIG. Quartz glass was used as the substrate 11, and Pt was used as the material of the device electrode in consideration of temperature resistance stability and oxidation resistance stability. The film thickness of the conductive film 14 is set to 30 nm here in consideration of the resistance value between the device electrodes 12 and 13 and the like. In this example, L is 20 μm, W is 100 μm, and film thickness d is 10 nm.
[0196]
The conductive film 14 is formed by applying an organic Pd solution (“ccp-4230” manufactured by Okuno Pharmaceutical Co., Ltd.) to the substrate 11 provided with the electrodes 12 and 13, forming an organometallic film, and subjecting it to a heat baking treatment. It was formed by patterning (FIGS. 2A and 2B).
[0197]
Next, the triangular wave pulse shown in FIG. 3 was continuously applied with a constant peak value. In FIG. 3, the pulse width T₁Is 100 μsec, pulse interval T₂Was set to 1 msec, and the peak value of the triangular wave was set to 10V. Under the above conditions, a pulse voltage was applied for 600 seconds to form the second gap 16 (FIG. 2C).
[0198]
Next, activation treatment was performed on the device. Specifically, the substrate on which the element is formed is placed in the apparatus of FIG. 4, and acetone is introduced as an organic substance gas into a vacuum that has been sufficiently evacuated once by an ion pump or the like.^-5At the same time, the same triangular wave pulse as that at the time of forming the second gap 16 was applied, and at the same time, the electron beam was irradiated with an acceleration voltage of 20 kV. However, the pulse width of the triangular wave pulse was 1 msec, the pulse interval was 10 msec, and the pulse peak value was 15V.
[0199]
The activation process, that is, the formation process of the carbon film 15 is performed by a predetermined element current I._fWent until it reached. As a result of observing the cross section of the obtained element with a transmission electron microscope, the film thickness was 50 nm in the vicinity of the gap 17. Further, the carbon film 15 is arranged to face each other with the first gap 17 as shown in FIG. Further, the first gap 17 is narrower than the second gap 16, and the first gap 17 is arranged in the second gap 16. As a result of observation such as Raman spectroscopy, the carbon film 15 contained a graphite structure and had high crystallinity.
[0200]
Further, as a result of observing the element with an atomic force / tunneling microscope in which the atomic force microscope probe is made conductive and the probe is brought into contact with the sample so that the conductivity distribution of the sample can be measured, the carbon film 15 is observed. It was found that there is no high resistance region. In this measurement, the probe was brought into contact with the carbon film 15 disposed on the conductive film 14 to perform the measurement. As a result of estimating the specific resistance in the film thickness direction, it was 0.001 Ωm or less. This value showed a change of one digit or more when compared with the value measured when the carbon film 15 was formed without electron irradiation.
[0201]
The element substrate was placed in the evaluation apparatus of FIG. 5, and the electron emission characteristics were measured with the voltage of the anode electrode set to 1 kV and the distance H between the anode electrode and the electron emission element set to 2 mm.
[0202]
First, in order to suppress the deposition of new carbon or carbon compounds, organic substances were exhausted from the vacuum vessel. The evacuation device 56 that evacuates the vacuum vessel 55 uses a sorption pump as a vacuum evacuation device that does not use oil so that oil generated from the device does not affect the characteristics of the element. The partial pressure of the organic component in the vacuum vessel 55 is 1 × 10 with a partial pressure at which the above carbon and carbon compounds are hardly deposited.^-8Pa or less. At this time, the entire vacuum vessel was heated at 200 ° C. or more to facilitate exhaust of organic substance molecules adsorbed on the inner wall of the vacuum vessel and the electron-emitting device.
[0203]
As a result, the device current I shown in FIG._fAnd emission current I_eThe relationship was obtained. Also, V_fIs fixed at 15 V and Va is fixed at 1 kV, and the electron emission is performed._fAgainst I_eThe electron emission efficiency η as a ratio of η was defined, and the time change of η was measured.
[0204]
As a result, first, the initial electron emission efficiency was improved by 0.05% or more. Furthermore, the time change of η was significantly suppressed as compared with the electron-emitting device manufactured by the conventional manufacturing method. In the conventional device, when the initial η is 0.1%, η is increased at a rate of 0.01% / 1000 h (h is time), whereas in the manufacturing method of the present invention, the change in η is observed. The ratio of was suppressed to 1/5 or less.
[0205]
(Example 2)
As a second embodiment of the present invention, an electron source having the configuration shown in FIG. 7 was produced through the activation treatment shown in FIG.
[0206]
The basic configuration, material, and manufacturing method were the same as in Example 1, but L1 was 5 μm, W was 100 μm, and the film thickness of the electrode was 10 nm. Further, the width L2 of the common element electrode was 5 μm.
[0207]
A device was formed in the same manner as in Example 1 until the electron emission portion was formed. Next, the common element electrode was set to the ground potential, and the activation voltage was applied to the element electrodes 73 and 74 by applying the pulse voltage shown in FIG. In this example, acetone is introduced as an organic substance and 1 × 10 6 is introduced.^-5Held at Pa. The condition of the applied pulse voltage is the pulse width t₁1msec, pulse voltage 15V, pulse interval t₂Was set to 20 msec. The conductive films 76 and 78 are formed by a predetermined element current I._fWent until it reached.
[0208]
As a result of observing a cross section of the obtained element with a transmission electron microscope, the film thickness of the carbon films 76 and 78 was 50 nm in the vicinity of the first gap 17 constituting the electron emission portion. Further, as a result of observing the obtained electron-emitting device with a transmission electron microscope, Raman spectroscopy, and the like, the carbon films 76 and 78 had a graphite structure and had high crystallinity.
[0209]
Furthermore, as a result of observing the element with an atomic force / tunnel microscope in which the probe of the atomic force microscope is made conductive as in Example 1 and the conductivity distribution of the sample can be measured, the carbon film 76, It was found that no high resistance region exists in 78. Moreover, as a result of estimating the specific resistance in the film thickness direction, it was 0.0001 Ωm or less. This value showed a change of two orders of magnitude or more compared with the value measured when the carbon film was formed without electron irradiation.
[0210]
The characteristics of the electron-emitting device prepared as described above were installed in the evaluation apparatus shown in FIG. 5, and the electron-emitting characteristics were examined. However, driving was performed only for one electron emission portion. The common element electrode side was set to a high potential so that electrons were always emitted to the common element electrode side. Also, V_fIs fixed at 15 V and Va is fixed at 1 kV._fAgainst I_eThe electron emission efficiency η as a ratio of η was defined, and the time change of η was measured.
[0211]
As a result, first, the initial electron emission efficiency was improved by 0.1% or more. Furthermore, the time change of η was significantly suppressed as compared with the electron-emitting device manufactured by the conventional manufacturing method. In the conventional device, when the initial η is 0.1%, η is increased at a rate of 0.01% / 1000 h (h is time), whereas in the manufacturing method of the present invention, the change in η is observed. The ratio of was suppressed to 1/10 or less.
[0212]
(Example 3)
In this example, an electron-emitting device having the configuration shown in FIG. 21 was produced. A present Example is described using FIG.21, FIG.22, FIG.23. Quartz glass was used as the substrate 11, and Pt was used as the material of the device electrodes 12 and 13 in consideration of temperature resistance stability and oxidation resistance stability.
[0213]
Next, the device was subjected to an activation process.
[0214]
Specifically, the substrate on which the device electrodes 12 and 13 are formed is placed in the apparatus shown in FIG. 23, and acetone is introduced as an organic substance gas into a vacuum that has been sufficiently exhausted by an ion pump or the like to obtain 1 × 10^-5The pulse shown in FIG. 8A was applied between the electrodes 12 and 13 while being held at Pa. T in FIG.₁Is 1msec, t₂Was 10 msec. At the same time, the electron beam was irradiated with an acceleration voltage of 2 kV.
[0215]
The carbon film 15 is formed by a predetermined element current I_fWent until it reached. As a result of observing the cross section of the obtained element with a transmission electron microscope, a first gap 17 is formed between the electrodes 12 and 13 as shown in FIG. It was formed continuously. The gap 17 was located approximately at the center of the electrodes 12 and 13. Further, as a result of observation such as Raman spectroscopy, the carbon film 15 has a graphite-like layer structure and has high crystallinity.
[0216]
The element substrate was placed in the evaluation apparatus of FIG. 5, and the electron emission characteristics were measured with the voltage of the anode electrode set to 1 kV and the distance H between the anode electrode and the electron emission element set to 2 mm.
[0217]
First, in order to suppress the deposition of new carbon or carbon compounds, organic substances were exhausted from the vacuum vessel. The evacuation device 66 that evacuates the vacuum vessel 65 uses a sorption pump as a vacuum evacuation device that does not use oil so that oil generated from the device does not affect the characteristics of the element. The partial pressure of the organic component in the vacuum vessel 65 is 1 × 10, which is a partial pressure at which the above carbon and carbon compounds are hardly deposited.^-8Pa or less. At this time, the entire vacuum vessel was heated at 200 ° C. or more to facilitate exhaust of organic substance molecules adsorbed on the inner wall of the vacuum vessel and the electron-emitting device.
[0218]
As a result, the device current I shown in FIG._fAnd emission current I_eThe relationship was obtained. Also, V_fIs fixed at 15 V and Va is fixed at 1 kV, and the electron emission is performed._fAgainst I_eDefine the electron emission efficiency η as a percentage of I_f, I_eThe initial value of η, its variation, and the change with time were measured.
[0219]
Example 4
In the present embodiment, the image forming apparatus 138 shown in FIG. 13 was created using the manufacturing method of the third embodiment. In this embodiment, the substrate 121 also serves as the rear plate 131.
[0220]
First, 500 sets of device electrodes 12 and 13 were formed on the glass substrate 121 by using an offset printing method in the X direction and 1000 sets in the Y direction (FIG. 24A). Subsequently, 500 X-direction wirings 122 connected to the electrode 12 were formed by a screen printing method (FIG. 24B). One thousand insulating layers 126 were formed by a screen printing method in a direction substantially perpendicular to the X-direction wiring (FIG. 24C). 1000 Y-direction wirings 123 were formed on the insulating layer 126 so as to be connected to the electrode 13 (FIG. 25D). As in the third embodiment, as shown in FIG. 23, the electron emission means 61 irradiates the electron beam between the element electrodes 12 and 13 in a DC manner while the element electrodes 12 and 13 are irradiated with each other. A voltage was applied to form a carbon film 15 (FIGS. 25E and 23). The electron source was formed by the above process.
[0221]
Subsequently, the electron source and the phosphor 142 which is an image forming member are aligned with the face plate 136 arranged as shown in FIG. 14A, and bonded between the electron source and the face plate. Sealing was performed by placing an outer frame 132 in which members were previously placed and heating and pressing in a vacuum atmosphere.
[0222]
The image forming apparatus 138 was formed through the above steps.
[0223]
When this image forming apparatus was connected to the drive circuit shown in FIG. 15 and driven, an image with high brightness and high uniformity could be stably displayed over a long period of time.
[0224]
(Example 5)
In the present embodiment, the image forming apparatus 138 shown in FIG. 13 was created using the manufacturing method of the first embodiment. In this embodiment, the substrate 121 also serves as the rear plate 131.
[0225]
First, 500 sets of device electrodes 12 and 13 were formed on the glass substrate 121 by using an offset printing method in the X direction and 1000 sets in the Y direction (FIG. 24A). Subsequently, 500 X-direction wirings 122 connected to the electrode 12 were formed by a screen printing method (FIG. 24B). One thousand insulating layers 126 were formed by a screen printing method in a direction substantially perpendicular to the X-direction wiring (FIG. 24C). On the insulating layer 126, 1000 Y-direction wirings 123 were formed so as to be connected to the electrode 13 (FIG. 26D). A conductive film 14 was formed between the device electrodes 12 and 13 by using an ink jet method (FIG. 26E). In the same manner as in Example 1, a voltage was applied between the element electrodes 12 and 13 to perform a forming process, thereby forming a second gap 16 (FIG. 26 (f)). As shown in FIGS. 2 and 4, a voltage is applied between the device electrodes 12 and 13 while irradiating the electron beam between the device electrodes 12 and 13 from the electron emission means 41 in a DC manner. A carbon film 15 was formed. The electron source was formed by the above process.
[0226]
Subsequently, the electron source and the phosphor 142 which is an image forming member are aligned with the face plate 136 arranged as shown in FIG. 14A, and bonded between the electron source and the face plate. Sealing was performed by placing an outer frame 132 in which members were previously placed and heating and pressing in a vacuum atmosphere.
[0227]
The image forming apparatus 138 was formed through the above steps.
[0228]
When this image forming apparatus was connected to the drive circuit shown in FIG. 15 and driven, an image with high brightness and high uniformity could be stably displayed over a long period of time.
[0229]
【The invention's effect】
According to the method for manufacturing an electron-emitting device of the present invention, a carbon film containing carbon as a main component can be formed while irradiating with sufficient electrons. A carbon film can be formed. Therefore, the initial electron emission efficiency is improved, and even if the carbon film is irradiated with electrons emitted from the electron emission portion during driving, the physical properties of the carbon film are hardly changed, and the electron emission efficiency does not change. Devices can be manufactured.
[0230]
Therefore, according to the present invention, an electron source capable of stably and uniformly obtaining high electron emission characteristics is provided, and an image forming apparatus having high luminance and high reliability is realized using the electron source.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing a configuration of a preferred embodiment of an electron-emitting device of the present invention.
FIG. 2 is a schematic diagram illustrating a manufacturing process of the electron-emitting device of FIG.
FIG. 3 is a diagram showing a voltage waveform used for forming an electron emission portion of the electron emission device of the present invention.
FIG. 4 is a schematic view showing an electron irradiation means used in an activation process of the method for manufacturing an electron-emitting device according to the present invention.
FIG. 5 is a schematic view of an evaluation apparatus for evaluating the electron emission characteristics of the electron-emitting device of the present invention.
FIG. 6 shows emission current I in the electron-emitting device of the present invention._e, Element current I_fAnd element voltage V_fIt is a figure which shows the relationship.
FIG. 7 is a diagram showing a configuration of a preferred embodiment of an electron source of the present invention.
8 is a diagram showing voltage waveforms used in the activation process of the electron source of FIG. 7;
9 is a schematic diagram showing an electron beam trajectory in the electron source activation step of FIG. 7; FIG.
FIG. 10 is a diagram showing another example of a voltage waveform used in the activation process of the electron source of the present invention.
FIG. 11 is a schematic view showing a conventional electron-emitting device.
FIG. 12 is a schematic configuration diagram showing an electron source having a simple matrix arrangement according to an embodiment of the electron source of the present invention.
FIG. 13 is a schematic configuration diagram of a display panel used in an embodiment of an image forming apparatus of the present invention using an electron source in a simple matrix arrangement.
14 is a view showing a phosphor film in the display panel shown in FIG.
15 is a diagram showing an example of a drive circuit for driving the display panel shown in FIG. 8. FIG.
FIG. 16 is a schematic configuration diagram showing an electron source in a ladder arrangement according to an embodiment of the electron source of the present invention.
FIG. 17 is a schematic configuration diagram of a display panel used in an embodiment of an image forming apparatus of the present invention using a ladder-shaped electron source.
FIG. 18 is a block diagram illustrating an example of an image forming apparatus of the present invention.
FIG. 19 is a schematic view showing an example of a method for manufacturing an electron-emitting device according to the present invention.
FIG. 20 is a schematic diagram showing one of the problems of the present invention.
FIG. 21 is a schematic view showing an example of an electron-emitting device of the present invention.
FIG. 22 is a schematic view showing an example of a method for manufacturing an electron-emitting device according to the present invention.
FIG. 23 is a schematic view showing an example of a method for manufacturing an electron-emitting device according to the present invention.
FIG. 24 is a schematic view showing an example of the production method of the present invention.
FIG. 25 is a schematic view showing an example of the production method of the present invention.
FIG. 26 is a schematic view showing an example of the production method of the present invention.
[Explanation of symbols]
11 Substrate
12, 13 Device electrode
l4 conductive film
15 Carbon film
16 Second gap
17 First gap
41 Electron beam irradiation means
42 Electron beam shielding means
50 Ammeter
51 power supply
52 Ammeter
53 High voltage power supply
54 Anode electrode
55 Vacuum container
56 Vacuum exhaust system
61 Electron emission means
62 pinhole
63 Electron beam blocking means
71 substrate
72 Common element electrode
73, 74 Device electrodes
75, 77 conductive film
76, 78 Conductive coating
79, 80, 100 Electron emission part
111 substrates
114 Conductive film
115 Electron emission part
121 Electron source substrate
122 X direction wiring
123 Y-direction wiring
124 surface conduction electron-emitting device
125 connection
126 Insulating layer
131 Rear plate
132 Support frame
133 Glass substrate
134 Fluorescent membrane
135 metal back
136 Face plate
137 High voltage terminal
138 Envelope
141 Black conductive material
142 phosphor
151 Display panel
152 Scanning Circuit
153 Control circuit
154 Shift register
155 line memory
156 Sync signal separation circuit
157 Modulation signal generator
160 Electron source substrate
161 Electron emitting device
162 Common wiring
170 Grid electrode
171 opening

Claims (7)

A pair of conductive films which are located opposite each other with a gap, the conductive film and disposed in said gap, the electron-emitting device having a carbon film to form a narrow gap than the gap in the gap The specific resistance in the film thickness direction of the carbon film on the conductive film is 0.001 Ωm or less. An electron source having a plurality of electron-emitting devices, wherein the electron-emitting device is the electron-emitting device according to claim 1. An image forming apparatus having an electron source and an image forming member, wherein the electron source is the electron source according to claim 2. 4. The image forming apparatus according to claim 3, further comprising a TV signal receiving circuit and a drive circuit for displaying an image based on the TV signal. 4. The image forming apparatus according to claim 3, further comprising: an image input interface circuit for connecting to the image input device; and a drive circuit for displaying an image based on a signal input from the circuit. . 4. The image forming apparatus according to claim 3, further comprising an image memory interface circuit for connecting to the image memory device, and a drive circuit for displaying an image based on a signal input from the circuit. . 4. An input / output interface circuit for connecting to an external computer, a computer network, or a printer, and a drive circuit for displaying an image based on a signal input from the circuit. The image forming apparatus described in 1.

Images