JP2010272259A - Method of manufacturing electron emitting element, electron emitting element, electron emitting device, charging device, image forming device, electron beam curing device, self-luminous device, image display device, blower, and cooling device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing an electron emitting element easily manufacturable in the atmosphere, and capable of stably and satisfactorily emitting electrons. <P>SOLUTION: After applying conductive particulate dispersion liquid in which conductive particulates 6 are dispersed in a dispersion solvent, insulator particulate dispersion liquid in which insulator particulates 5 each having an average particle diameter larger than that of the conductive particulate 6 are dispersed is applied onto an electrode substrate 2 to form the electron accelerating layer 4 of this electron emitting element 1. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for manufacturing an electron-emitting device that emits electrons by applying a voltage, an electron-emitting device, and the like.

  As a conventional electron-emitting device, a Spindt type electrode, a carbon nanotube (CNT) type electrode, and the like are known. Such an electron-emitting device has been studied for application in the field of FED (Field Emission Display), for example. In such an electron-emitting device, a voltage is applied to the sharp portion to form a strong electric field of about 1 GV / m, and electrons are emitted by the tunnel effect.

  However, since these two types of electron-emitting devices have a strong electric field in the vicinity of the surface of the electron-emitting region, the emitted electrons easily obtain a large energy by the electric field and easily ionize gas molecules. There is a problem that cations generated by ionization of gas molecules are accelerated and collided in the direction of the surface of the device by a strong electric field, and device destruction occurs due to sputtering. Moreover, since oxygen in the atmosphere has lower dissociation energy than ionization energy, ozone is generated prior to the generation of ions. Since ozone is harmful to the human body and oxidizes various things with its strong oxidizing power, there is a problem of damaging members around the element. To avoid this, the surrounding members are ozone resistant. There is a restriction that high material must be used.

  On the other hand, MIM (Metal Insulator Metal) and MIS (Metal Insulator Semiconductor) type electron-emitting devices are known as other types of electron-emitting devices. These are surface emission type electron-emitting devices that use the quantum size effect and strong electric field inside the device to accelerate electrons and emit electrons from the planar device surface. Since these emit electrons accelerated by the electron acceleration layer inside the device, a strong electric field is not required outside the device. Therefore, the MIM type and MIS type electron-emitting devices have a problem that they are destroyed by sputtering due to ionization of gas molecules, and ozone is generated, like the Spindt-type, CNT-type, and BN-type electron-emitting devices. It can be overcome.

  For example, Patent Document 1 discloses an electron-emitting device in which a lower electrode, a conductive layer, an insulating layer, and an upper electrode are formed on a substrate, and a part or all of elements constituting the insulating layer in the insulating layer. An electron-emitting device containing a fine particle or a defect structure consisting of is disclosed. In this electron-emitting device, when a predetermined voltage is applied between the upper electrode and the lower electrode, electrons pass from the lower electrode through the conductive layer, are transmitted through the fine particles or defect structure in the insulating layer, and are accelerated into the vacuum from the upper electrode. Electrons are emitted. The electron-emitting device disclosed in Patent Document 1 has a stacked structure as described above, so that the electron-emitting trajectory is substantially perpendicular to the substrate surface, so that the straightness of electrons is good and suitable for an image display device. It has been reported.

JP 11-297190 A (published November 29, 1999)

  However, when the electron-emitting device of Patent Document 1 is manufactured according to the description of the embodiments, it is generally necessary to manufacture it in a vacuum system, and the manufacturing apparatus becomes large.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a method for manufacturing an electron-emitting device that can be easily manufactured in the air and can emit electrons stably and satisfactorily. It is.

  In order to solve the above-described problems, a method for manufacturing an electron-emitting device of the present invention includes an electrode substrate, a thin film electrode, and an electron acceleration layer between the electrode substrate and the thin film electrode. When the voltage is applied between the thin film electrode and the thin film electrode, the electron acceleration layer accelerates the electron to emit the electron from the thin film electrode. Then, after applying a conductive fine particle dispersion in which conductive fine particles are dispersed in a dispersion solvent, an insulating fine particle dispersion in which insulator fine particles having an average particle size larger than that of the conductive fine particles is dispersed in a dispersion solvent is applied. An electron acceleration layer forming step for forming the electron acceleration layer is included.

  According to the above method, the electron-emitting device having the electron acceleration layer including the insulating fine particles and the conductive fine particles between the electrode substrate and the thin film electrode is obtained by a simple manufacturing process in which both fine particles are applied on the electrode substrate. The device can be manufactured in the atmosphere. However, since the electron acceleration layer is made of fine particles, the contact between the electrode substrate and the fine particles serves as a conductive path between the electrode and the electron acceleration layer, so that the current path is limited. Therefore, after applying the conductive fine particle dispersion on the electrode substrate, the insulator fine particle dispersion is applied to form an electron acceleration layer, so that many conductive fine particles exist at the interface between the electrode substrate and the electron acceleration layer. Can do. As a result, a large number of conductive paths between the electrode substrate and the electron acceleration layer can be secured, so that an electron-emitting device capable of obtaining a stable and good electron emission amount can be manufactured.

  When the insulating fine particle dispersion is applied from above the conductive fine particle layer, most of the conductive fine particles remain formed on the electrode substrate, but some of the conductive fine particles drop the insulating fine particle dispersion. So that it is mixed in the insulator fine particle dispersion and remains in the insulator particle layer even after the dispersion solvent in the insulator fine particle volatilizes. It is thought that an electron acceleration layer with a little mixed is made.

  Therefore, according to the above method, it is possible to easily manufacture in the atmosphere, and it is possible to easily manufacture in the atmosphere an electron-emitting device capable of emitting electrons stably and satisfactorily. A dischargeable electron-emitting device can be manufactured.

  In the method for manufacturing an electron-emitting device of the present invention, in addition to the above method, the insulating fine particle dispersion and the conductive fine particle dispersion may contain different dispersion solvents.

  Here, the following problems occur when the insulating fine particles and the conductive fine particles have different dispersion solvents that are easy to disperse. In the case where the insulating fine particle dispersion and the conductive fine particle dispersion contain different dispersion solvents, agglomerates are likely to occur when both fine particles are mixed. Therefore, in order to prevent the formation of aggregates when both fine particles are mixed, if one of the insulating fine particles and the conductive fine particles is aligned with a dispersion solvent having good dispersibility, the dispersibility of the fine particles is reduced in the other dispersion. Aggregates are generated. Therefore, it does not solve the generation of aggregates after all.

  However, according to the above method according to the present invention, the insulating fine particle dispersion liquid is applied after the conductive fine particle dispersion is applied without mixing both, even if the dispersion fine particles of the insulating fine particles and the conductive fine particles are different. By applying, an electron acceleration layer can be formed while maintaining the dispersibility of both fine particles. That is, a uniform electron acceleration layer that does not contain aggregates of insulating fine particles or conductive fine particles can be formed even if the dispersion solvent having high dispersibility is different between the insulating fine particles and the conductive fine particles.

  In the method for manufacturing an electron-emitting device according to the present invention, in addition to the above method, the average particle diameter of the insulating fine particles is preferably 3 to 10 nm.

  By setting the average particle diameter of the conductive fine particles to 3 to 10 nm, a conductive path due to the conductive fine particles is not formed in the electron acceleration layer, and dielectric breakdown does not easily occur in the electron acceleration layer. Although there are many unclear points in principle, ballistic electrons are efficiently generated by using conductive fine particles having an average particle diameter within the above range.

  The average particle size of the insulating fine particles is preferably 10 to 500 nm. In this case, the dispersion state of the particle diameter may be broad with respect to the average particle diameter. For example, fine particles having an average particle diameter of 50 nm may have a particle diameter distribution in the region of 20 to 100 nm. Since the average particle size of the insulating fine particles is larger than the average particle size of the conductive fine particles, heat can be efficiently conducted from the inside to the outside of the conductive fine particles smaller than the average particle size of the insulating fine particles, and the current inside the device Joule heat generated when flowing can be efficiently released, and the electron-emitting device can be prevented from being destroyed by heat. Furthermore, the resistance value in the electron acceleration layer can be easily adjusted.

  Here, if the average particle diameter of the insulating fine particles is smaller than 10 nm, the number of conductive fine particles in contact with one insulating fine particle is small between the conductive fine particle layer and the electron accelerating layer, and from the electrode substrate to the electron accelerating layer. The effect as a conductive fine particle layer of forming a large number of conductive paths cannot be exhibited. On the other hand, when the average particle size of the insulating fine particles is larger than 500 nm, the number of conductive fine particles in contact with one insulating fine particle is large between the conductive fine particle layer and the electron acceleration layer, but the gap between the insulating fine particles. Therefore, there are few conductive paths in the entire element, and there is a disadvantage that the effect as the conductive fine particle layer cannot be exhibited. Therefore, when using conductive fine particles having an average particle diameter of 3 to 10 nm, the average particle diameter of the insulating fine particles is preferably 10 to 500 nm.

  In addition to the above method, in the method for manufacturing an electron-emitting device of the present invention, the nanoparticle colloid liquid of conductive particles may be used in a liquid state as the dispersion liquid of the conductive particles.

  According to the above method, a nano colloidal solution of conductive fine particles is applied to the insulator layer. Here, when the nanocolloid liquid is used in a liquid state, the conductive fine particles are dispersed, and it is difficult to form an aggregate. Therefore, dispersed conductive fine particles having no interparticle aggregation can be applied on the electrode substrate.

  In order to solve the above-mentioned problems, an electron-emitting device according to the present invention is manufactured by any one of the above-described methods for manufacturing an electron-emitting device.

  In the electron-emitting device manufactured by the method according to the present invention, the electron acceleration layer between the electrode substrate and the thin film electrode is a thin film layer in which insulator fine particles and conductive fine particles are dispersed and has semiconductivity. . When a voltage is applied to the semiconductive electron acceleration layer, a current flows in the electron acceleration layer, and a part thereof is emitted as ballistic electrons by the strong electric field formed by the applied voltage. Here, the electron acceleration layer of the electron-emitting device has many conductive fine particles at the interface between the electrode substrate and the electron acceleration layer. As a result, the conductivity between the electrode substrate and the electron acceleration layer is improved (since many conductive paths between the electrode substrate and the electron acceleration layer can be secured), and a stable and good electron emission amount can be obtained.

  The electron-emitting device of the present invention includes any one of the above-described electron-emitting devices and a power supply unit that applies a voltage between the electrode substrate and the thin-film electrode.

  According to the above configuration, it is possible to ensure electrical continuity and to allow a sufficient current to flow inside the electron-emitting device, so that ballistic electrons can be stably and satisfactorily emitted from the thin-film electrode.

  Further, by using the electron emission device of the present invention for a charging device and an image forming apparatus equipped with the charging device, electrons can be emitted with high efficiency, so that charging can be performed with high efficiency. Furthermore, the object to be charged can be stably charged for a long period of time without generating harmful substances such as ozone and NOx without discharging.

  Further, by using the electron emission device of the present invention in an electron beam curing device, it is possible to emit electrons stably and satisfactorily, so that an electron beam can be irradiated with high stability and goodness. In addition, the electron beam can be cured in terms of area, masklessness can be achieved, and low cost and high throughput can be realized.

  Further, by using the electron emitting device of the present invention for a self-luminous device and an image display device equipped with the self-luminous device, electrons can be emitted stably and satisfactorily, and light can be emitted with high efficiency. In addition, it is possible to provide a self-luminous device that realizes stable and good surface light emission.

  Further, by using the electron emission device of the present invention for a blower device or a cooling device, electrons can be emitted stably and satisfactorily, so that it can be cooled stably and satisfactorily. Further, no harmful substances such as ozone and NOx are generated without discharge, and cooling can be efficiently performed by utilizing the slip effect on the surface of the object to be cooled.

  As described above, the method for manufacturing an electron-emitting device according to the present invention includes applying a conductive fine particle dispersion in which conductive fine particles are dispersed in a dispersion solvent to the electrode substrate, and then having an average particle size of that of the conductive fine particles. It includes an electron acceleration layer forming step of forming the electron acceleration layer by applying an insulator fine particle dispersion in which large insulator fine particles are dispersed in a dispersion solvent.

  According to the above method, the electron-emitting device having the electron acceleration layer including the insulating fine particles and the conductive fine particles between the electrode substrate and the thin film electrode is obtained by a simple manufacturing process in which both fine particles are applied on the electrode substrate. The device can be manufactured in the atmosphere. However, since the electron acceleration layer is made of fine particles, the contact between the electrode substrate and the fine particles serves as a conductive path between the electrode and the electron acceleration layer, so that the current path is limited. Therefore, after applying the conductive fine particle dispersion on the electrode substrate, the insulator fine particle dispersion is applied to form an electron acceleration layer, so that many conductive fine particles exist at the interface between the electrode substrate and the electron acceleration layer. Can do. As a result, a large number of conductive paths between the electrode substrate and the electron acceleration layer can be secured, so that an electron-emitting device capable of obtaining a stable and good electron emission amount can be manufactured.

  When the insulating particle dispersion is applied from above the conductive fine particle layer, most of the conductive fine particles remain formed on the electrode substrate, but some of the conductive fine particles drop the insulating fine particle dispersion. So that it is mixed in the insulator fine particle dispersion and remains in the insulator particle layer even after the dispersion solvent in the insulator fine particle volatilizes. It is thought that an electron acceleration layer with a little mixed is made.

  Therefore, according to the above method, it is possible to easily manufacture in the atmosphere, and it is possible to easily manufacture in the atmosphere an electron-emitting device capable of emitting electrons stably and satisfactorily. A dischargeable electron-emitting device can be manufactured.

It is a schematic diagram which shows the structure of the electron-emitting element of this invention. It is a schematic diagram which shows the structure of the electron emission apparatus of this invention. It is a figure which shows the measurement system of an electron emission experiment. It is a figure which shows an example of the charging device using the electron emission apparatus of this invention. It is a figure which shows an example of the electron beam hardening apparatus using the electron emission apparatus of this invention. It is a figure which shows an example of the self-light-emitting device using the electron emission apparatus of this invention. It is a figure which shows another example of the self-light-emitting device using the electron emission apparatus of this invention. It is a figure which shows another example of the self-light-emitting device using the electron emission apparatus of this invention. It is a figure which shows another example of the image display apparatus which comprises the self-light-emitting device using the electron emission apparatus of this invention. It is a figure which shows an example of the air blower using the electron emission apparatus of this invention, and a cooling device provided with the same. It is a figure which shows another example of the air blower using the electron-emitting apparatus of this invention, and a cooling device provided with the same.

  Hereinafter, embodiments and examples of the electron-emitting device of the present invention will be specifically described with reference to FIGS. Note that the embodiments and examples described below are merely specific examples of the present invention, and the present invention is not limited thereto.

[Embodiment 1]
(Configuration of electron-emitting device)
FIG. 1 is a schematic diagram showing a part of the configuration of an electron-emitting device according to an embodiment of the present invention. As shown in FIG. 1, an electron-emitting device 1 according to this embodiment includes an electrode substrate 2 serving as a lower electrode, a thin film electrode 3 serving as an upper electrode, an electron acceleration layer 4 existing therebetween, an electrode substrate 2 and an electron. It consists of a conductive fine particle layer 16 between the acceleration layer 4. FIG. 2 is a view showing an electron emission apparatus according to an embodiment of the present invention having the electron emission element 1. As shown in FIG. 2, the electrode substrate 2 and the thin film electrode 3 are connected to a power source 7, and a voltage can be applied between the electrode substrate 2 and the thin film electrode 3 arranged to face each other. . The electron-emitting device 1 applies a voltage between the electrode substrate 2 and the thin film electrode 3, thereby passing a current between the electrode substrate 2 and the thin film electrode 3, that is, the electron acceleration layer 4. The thin film electrode 3 is transmitted and / or emitted from the gap between the thin film electrodes 3 as ballistic electrons by the strong electric field formed by the applied voltage. The electron emission device 10 is composed of the electron emission element 1 and the power source 7.

  The electrode substrate 2 serving as the lower electrode serves as a support for the electron-emitting device. Therefore, any material can be used without particular limitation as long as it has a certain degree of strength, has good adhesion to a directly contacting substance, and has appropriate conductivity. Examples thereof include metal substrates such as SUS, Ti, and Cu, semiconductor substrates such as Si, Ge, and GaAs, insulator substrates such as glass substrates, and plastic substrates. For example, if an insulator substrate such as a glass substrate is used, it can be used as the electrode substrate 2 to be the lower electrode by attaching a conductive material such as a metal as an electrode to the interface with the electron acceleration layer 4. . The conductive material is not particularly limited as long as a material having excellent conductivity can be formed into a thin film using magnetron sputtering or the like. However, if a stable operation in the air is desired, it is preferable to use a conductor with high antioxidation power, and it is more preferable to use a noble metal. An ITO thin film widely used for transparent electrodes is also useful as an oxide conductive material. In addition, for example, a metal thin film in which a Ti film is formed to 200 nm on a glass substrate surface and a Cu film is further formed to a 1000 nm thickness may be used in that a tough thin film can be formed. Never happen.

  The thin film electrode 3 applies a voltage in the electron acceleration layer 4. Therefore, any material that can be applied with voltage can be used without particular limitation. However, from the standpoint that electrons accelerated and become high energy in the electron acceleration layer 4 are transmitted with as little energy loss as possible and emitted, a material having a low work function and capable of forming a thin film is higher. The effect can be expected. Examples of such a material include gold, silver, carbon, tungsten, titanium, aluminum, palladium, and the like whose work function corresponds to 4 to 5 eV. In particular, assuming operation at atmospheric pressure, gold without oxide and sulfide formation reaction is the best material. In addition, silver, palladium, tungsten, and the like, which have a relatively small oxide formation reaction, are materials that can withstand actual use without problems. The film thickness of the thin-film electrode 3 is important as a condition for efficiently emitting electrons from the electron-emitting device 1 to the outside, and is preferably in the range of 10 to 55 nm. The minimum film thickness for causing the thin film electrode 3 to function as a planar electrode is 10 nm. If the film thickness is less than this, electrical conduction cannot be ensured. On the other hand, the maximum film thickness for emitting electrons from the electron-emitting device 1 to the outside is 55 nm. If the film thickness exceeds this, no ballistic electrons are transmitted, and the thin-film electrode 3 accelerates electrons by absorbing or reflecting ballistic electrons. Recapture into layer 4 will occur.

  As shown in FIG. 1, in the electron acceleration layer 4, insulator fine particles 5 and conductive fine particles 6 are dispersed, and the conductive fine particles 6 are unevenly distributed on the electrode substrate 2 side. That is, a part of the conductive fine particles 6 constituting the conductive fine particle layer 16 exists in the electron acceleration layer 4. Alternatively, the electron acceleration layer 4 is divided into a fine particle layer containing the insulating fine particles 5 and no conductive fine particles 6 and a conductive fine particle layer 16.

The insulating fine particles 5 can be used without particular limitation as long as the material has insulating properties. As the material of the insulating fine particles 5, for example, a material such as SiO ₂ , Al ₂ O ₃ , or TiO ₂ becomes practical. However, using small-sized silica particles with surface treatment increases the surface area of the silica particles in the solvent and increases the solution viscosity compared to using spherical silica particles with a larger particle diameter. Therefore, the film thickness of the electron acceleration layer 4 tends to increase slightly. The material of the insulating fine particles 5 may be fine particles made of an organic polymer. For example, highly crosslinked fine particles (SX8743) made of styrene / divinylbenzene manufactured and sold by JSR Corporation, or manufactured by Nippon Paint Corporation. The fine sphere series of styrene / acrylic fine particles to be sold is available. Here, the insulating fine particles 5 may use two or more kinds of different particles, may use particles having different particle size peaks, or have a single particle and a broad distribution of particle sizes. May be used.

  The average particle diameter of the insulating fine particles 5 is preferably larger than the average particle diameter of the conductive fine particles 6 in order to obtain a heat radiation effect superior to that of the conductive fine particles 6. In this case, the dispersion state of the particle diameter may be broad with respect to the average particle diameter. For example, fine particles having an average particle diameter of 50 nm may have a particle diameter distribution in the region of 20 to 100 nm. If the insulating fine particles 5 are larger than the average particle size of the conductive fine particles 6, the conductive fine particles 6 smaller than the average particle size of the insulating fine particles 5 are efficiently conducted from the inside to the outside, and a current flows in the element. Joule heat generated at the time can be efficiently released, and the electron-emitting device can be prevented from being destroyed by heat. Furthermore, the resistance value in the electron acceleration layer 4 can be easily adjusted.

  Further, when the electron acceleration layer 4 is formed by applying the conductive fine particles 6 on the fine particle layer including the insulating fine particles 5 as described later, the degree of penetration of the conductive fine particles 6 into the fine particle layer is determined by the insulating fine particles 5. It depends on the type and / or average particle size, the type and / or average particle size of the conductive fine particles 6, the combination of the insulating fine particles 5 and the conductive fine particles 6, and the like. That is, when the average particle diameter of the insulating fine particles 5 is small, most of the applied conductive fine particles 6 do not penetrate into the fine particle layer and deposit on the upper part. On the other hand, when the average particle diameter of the insulating fine particles 5 is large, the gaps between the particles of the fine particle layer become too large, and the conductive fine particles 6 staying in the fine particle layer are reduced. Therefore, in order to control the degree of penetration of the conductive fine particles into the fine particle layer when using the conductive fine particles 6 having an average particle diameter of 3 to 10 nm, the average particle diameter of the insulating fine particles 5 is 10 to 500 nm. preferable.

  As the material of the conductive fine particles 6, any conductor can be used on the principle of operation of generating ballistic electrons. However, if the conductor has a high anti-oxidation power, oxidative deterioration when operating at atmospheric pressure can be avoided. Here, the high antioxidant power means that the oxide forming reaction is low. In general, the larger the negative value ΔG [kJ / mol] value of the oxide formation free energy obtained by thermodynamic calculation, the easier the oxide formation reaction occurs. In the present invention, a metal element corresponding to ΔG> −450 [kJ / mol] or more corresponds to conductive fine particles having a high antioxidant power. In addition, the conductive fine particles in a state in which an oxide generation reaction is more difficult to occur by attaching or coating an insulating material smaller than the size of the conductive fine particles around the corresponding conductive fine particles have anti-oxidation power. Included in high conductive particles. The conductive fine particles having high anti-oxidation power can prevent device deterioration such as oxidation of the conductive fine particles by oxygen in the atmosphere. Therefore, the lifetime of the electron-emitting device can be extended.

  Examples of the conductive fine particles having high anti-oxidation power include materials such as noble metals such as gold, silver, platinum, palladium, and nickel. Such conductive fine particles 6 can be prepared using a known fine particle production technique such as sputtering or spray heating, and also use commercially available metal fine particle powders such as silver nanoparticles produced and sold by Applied Nano Laboratory. Is possible. The principle of ballistic electron generation will be described later.

  Here, the average particle diameter of the conductive fine particles 6 is more preferably 3 to 10 nm. Thus, by setting the average particle diameter of the conductive fine particles 6 to preferably 3 to 10 nm, a conductive path by the conductive fine particles 6 is not formed in the electron acceleration layer 4, and dielectric breakdown in the electron acceleration layer 4 is achieved. Is less likely to occur. Although there are many unclear points in principle, ballistic electrons are efficiently generated by using the conductive fine particles 6 having an average particle diameter within the above range.

  The proportion of the conductive fine particles 6 in the entire electron acceleration layer 4 is preferably 0.5 to 30% by weight. When the amount is less than 0.5% by weight, the effect of increasing the current in the device as conductive fine particles is not exhibited, and when the amount is more than 30% by weight, aggregation of the conductive fine particles occurs. Especially, it is more preferable that it is 1 to 10 weight%.

  Note that a small insulator material, which is an insulator material smaller than the size of the conductive fine particles 6, may exist around the conductive fine particles 6, and the small insulator material adheres to the surface of the conductive fine particles 6. The substance may be a substance, and the attached substance may be an insulating film that coats the surface of the conductive fine particles 6 as an aggregate having a shape smaller than the average particle diameter of the conductive fine particles 6. As the small insulator material, any insulator material can be used on the principle of operation of generating ballistic electrons. However, when the insulating material smaller than the size of the conductive fine particle 6 is an insulating film that coats the conductive fine particle 6, and the insulating film is covered by the oxide film of the conductive fine particle 6, the thickness of the oxide film due to oxidative degradation in the atmosphere. In order to avoid oxidative degradation when operated at atmospheric pressure, an insulating film made of an organic material is preferable. For example, materials such as alcoholate, fatty acid, and alkanethiol are listed. It is done. It can be said that the thinner the insulating coating, the more advantageous.

  In addition, the conductive fine particles 6 are preferably subjected to a surface treatment in order to improve dispersibility when preparing a dispersion of conductive fine particles in the production method described later, and the surface treatment is performed on the above insulating coating substance. It may be to coat.

  In addition, the conductive fine particles 6 partially or entirely of the conductive fine particles 6 included in the electron acceleration layer 4 are present as the conductive fine particle layer 16. By forming the conductive fine particle layer 16, many current paths flowing from the electrode substrate 2 to the electron acceleration layer 4 can be secured.

  In addition, the thinner the electron acceleration layer 4 is, the stronger the electric field is applied, so that electrons can be accelerated by applying a low voltage, but the layer thickness can be made uniform and the resistance of the electron acceleration layer in the layer thickness direction can be adjusted. Therefore, the layer thickness of the electron acceleration layer 4 is preferably 12 to 6000 nm, and more preferably 300 to 6000 nm.

(Electron emission principle)
Next, the principle of electron emission of the electron-emitting device 1 when a part of the conductive fine particles 6 is present in the electron acceleration layer 4 is considered as follows. As shown in FIG. 1, most of the electron acceleration layer 4 is composed of insulating fine particles 5, and conductive fine particles 6 are scattered in the gaps. The ratio between the insulating fine particles 5 and the conductive fine particles 6 is such that the weight ratio of the insulating fine particles 5 to the total weight of the insulating fine particles 5 and the conductive fine particles 6 corresponds to, for example, 80%. As described above, the electron acceleration layer 4 is composed of the insulating fine particles 5 and the small number of conductive fine particles 6, and thus has semiconductivity. Therefore, when a voltage is applied to the electron acceleration layer 4, a very weak current flows. At this time, since a part of the conductive fine particles 6 is the conductive fine particle layer 16, many current paths flowing from the electrode substrate 2 to the electron acceleration layer 4 can be secured. The voltage-current characteristic of the electron acceleration layer 4 shows a so-called varistor characteristic, and the current value is rapidly increased as the applied voltage increases. Part of this current becomes ballistic electrons due to a strong electric field in the electron acceleration layer 4 formed by the applied voltage, and is transmitted through the thin film electrode 3 or passed through the gap and emitted to the outside of the electron-emitting device 1. The formation process of ballistic electrons is thought to be due to electrons tunneling while being accelerated in the direction of the electric field, but it has not been determined.

  The principle of electron emission of the electron-emitting device 1 when the electron acceleration layer 4 is divided into a fine particle layer not including the conductive fine particles 6 but including the insulating fine particles 5 and a conductive fine particle layer 16 is as follows. Conceivable. The electron emission mechanism of the electron emission element 1 is considered to be similar to the operation mechanism in a so-called MIM type electron emission element in which an insulator layer is inserted between two conductor films. In the MIM type electron-emitting device, when an electric field is applied to the insulator layer, a general mechanism for forming a current path is as follows: a) diffusion of electrode material into the insulator layer, b) insulator material C) formation of a conductive path called a filament, d) stoichiometric deviation of the insulator material, e) trapping of electrons due to defects in the insulator material, and local formation of the trapped electrons Various theories such as a strong electric field region have been considered, but are not clear. For any reason, according to the configuration of the electron-emitting device 1 of the present invention, such an electric current path is applied when an electric field is applied to the electron acceleration layer 4 composed of the fine particle layer including the insulating fine particles 5 corresponding to the insulating layer. And a part of the current is accelerated by the electric field, resulting in ballistic electrons, passing through the thin film electrode 3 which is one of the electrode substrate 2 and the thin film electrode 3 corresponding to two conductor films, It is considered that electrons are emitted out of the device. Also in this case, the conductive fine particle layer 16 can secure a large number of current paths that flow from the electrode substrate 2 to the electron acceleration layer 4 that does not include the conductive fine particles 6.

  Here, for example, using the interpretation of e), it can be explained as follows. When a voltage is applied between the electrode substrate 2 and the thin film electrode 3, electrons move from the electrode substrate 2 to the surface of the insulating fine particles 5. Since the inside of the insulating fine particles 5 has a high resistance, electrons are conducted through the surface of the insulating fine particles 5. At this time, electrons are trapped in impurities on the surface of the insulating fine particles 5, oxygen defects that may occur when the insulating fine particles 5 are oxides, or contacts between the insulating fine particles 5. The trapped electrons work as fixed charges. As a result, in the vicinity of the thin film electrode 3 of the electron acceleration layer 4, the applied voltage and the electric field generated by the trapped electrons are combined to locally form a high electric field region, and the high electric field accelerates the electrons from the thin film electrode 3. Electrons are emitted.

(Production method)
Next, an embodiment of a method for manufacturing the electron-emitting device 1 of the present invention will be described.

First, an insulating fine particle dispersion in which the insulating fine particles 5 are dispersed in a dispersion solvent is obtained. For example, it can be obtained by dispersing the insulating fine particles 5 in a dispersion solvent. The dispersion method is not particularly limited, and for example, it may be dispersed by applying an ultrasonic disperser at room temperature. The dispersion solvent used here can be used without particular limitation as long as the insulating fine particles 5 can be dispersed and dried after coating. For example, toluene, benzene, hexane, methanol, ethanol and the like can be mentioned. Here, the dispersion solvent suitable for dispersion varies depending on the type of the insulating fine particles 5. For example, when the insulating fine particles 5 are SiO ₂ , methanol or ethanol is preferable. Moreover, a dispersion | distribution solvent can be used individually or in combination of 2 or more types, respectively.

  On the other hand, a conductive fine particle dispersion in which the conductive fine particles 6 are dispersed in a dispersion solvent is obtained. For example, the conductive fine particles 6 may be dispersed in a dispersion solvent, or a commercially available product may be used. The dispersion method is not particularly limited, and for example, it may be dispersed using an ultrasonic disperser at room temperature. Any dispersion solvent can be used without particular limitation as long as the conductive fine particles 6 can be dispersed and dried after coating. Here, in order to improve the dispersibility, when the conductive fine particles 6 are subjected to a surface treatment, it is preferable to use a dispersion solvent suitable for dispersion depending on the surface treatment method. For example, toluene or hexane is preferable for the conductive fine particles 6 whose surface is treated with alcoholate.

  Further, as the conductive fine particle dispersion, a nano colloid liquid of conductive fine particles 6 may be used in a liquid state. When the nanocolloid liquid of the conductive fine particles 6 is used in a liquid state, the electron acceleration layer 4 in which the conductive fine particles 6 are uniformly dispersed can be formed. The conductive fine particles 6 preferably have an average particle size in a colloidal state of 0.35 μm or less. By using conductive fine particles having an average particle size in the colloidal state of 0.35 μm or less, the dispersibility in the electron acceleration layer 4 can be enhanced as described in Examples described later. Examples of the nano colloid liquid of the conductive fine particles 6 include gold nano particle colloid liquid manufactured and sold by Harima Kasei Co., Ltd., silver nano particles manufactured and sold by Applied Nano Laboratory, and platinum nano manufactured and sold by Tokuru Chemical Laboratory Co., Ltd. Examples thereof include a particle colloid solution and a palladium nanoparticle colloid solution, and a nickel nanoparticle paste manufactured and sold by IOX Co., Ltd. In addition, as the solvent of the nano colloid liquid of the conductive fine particles 6, the insulating fine particles 5 can be used without particular limitation as long as the fine particles can be colloidally dispersed and dried after coating. For example, toluene, benzene, xylene, hexane, tetradecane, etc. Can be used.

  Then, the conductive fine particle dispersion is applied on the electrode substrate 2 by using a spin coating method to form a conductive fine particle layer. As a coating method, for example, a dropping method may be used in addition to the spin coating method. After the dispersion solvent is volatilized and dried, the insulating fine particle dispersion or the insulating fine particle-containing binder component dispersion is applied onto the conductive fine particle layer to obtain a fine particle layer containing the insulating fine particles 5. As a coating method, for example, a dropping method may be used in addition to the spin coating method. In the electron acceleration layer 4 formed by the above method, since part or all of the conductive fine particles 6 are present on the electrode substrate side, it is assumed that the electron acceleration layer 4 is not conductive. However, when the insulating fine particle dispersion is applied from above the conductive fine particle layer, most of the conductive fine particles still form the layer 16 on the substrate. However, even after some of the conductive fine particles 6 are swollen by an impact when the insulating fine particle dispersion is dropped, and mixed with the insulating fine particle dispersion, and the dispersion solvent in the insulating fine particle dispersion volatilizes, the insulating fine particles By remaining in the layer, the electron acceleration layer 4 in which the conductive fine particles are mixed a little in the insulator fine particle layer can be formed. Therefore, it is considered that conductivity is imparted to the electron acceleration layer.

  Thus, the electron acceleration layer 4 is formed. After the formation of the electron acceleration layer 4, the thin film electrode 3 is formed on the electron acceleration layer 4. For forming the thin film electrode 3, for example, a magnetron sputtering method may be used. The thin film electrode 3 may be formed by using, for example, an ink jet method, a spin coat method, a vapor deposition method, or the like.

  According to the above manufacturing method, the device can be manufactured in the atmosphere by a simple manufacturing process. Furthermore, after applying the conductive fine particle dispersion onto the electrode substrate 2, the insulating fine particle dispersion is applied to form the electron acceleration layer 4, whereby the conductive fine particles 6 are formed at the interface between the electrode substrate 2 and the electron acceleration layer 4. There can be many. As a result, a large number of conductive paths between the electrode substrate 2 and the electron acceleration layer 4 can be secured, so that an electron-emitting device capable of obtaining a stable and good electron emission amount can be manufactured.

  Therefore, according to the above method, it is possible to easily manufacture in the atmosphere, and it is possible to easily manufacture in the atmosphere an electron-emitting device capable of emitting electrons stably and satisfactorily. A dischargeable electron-emitting device can be manufactured.

  Further, in the above method, since the conductive fine particle dispersion solution and the insulating fine particle dispersion solution are respectively prepared and separately applied onto the electrode substrate 2, the aggregates at the time of mixing the insulating fine particle dispersion solution and the conductive fine particle dispersion solution are reduced. Generation | occurrence | production and the malfunction that an aggregate generate | occur | produces when electrically conductive fine particles are added to the insulator fine particle dispersion can be prevented. Therefore, by applying the insulating fine particle dispersion after applying the conductive fine particle dispersion on the electrode substrate 2, the electron acceleration layer 4 in which the fine particles are uniformly dispersed and the fine particles are uniformly dispersed can be formed.

(Example)
In the following examples, an experiment in which current is measured using an electron-emitting device manufactured using the manufacturing method according to the present invention will be described. In addition, this experiment is an example of implementation and does not limit the content of the present invention.

  First, the electron-emitting device of Example 1 and the electron-emitting device of Comparative Example 1 were produced as follows. And about the produced electron emission element, the measurement experiment of the electron emission current per unit area was conducted using the experimental system shown in FIG. In the experimental system of FIG. 3, the counter electrode 8 is disposed on the thin film electrode 3 side of the electron-emitting device 1 with the insulator spacer 9 interposed therebetween. The electron-emitting device 1 and the counter electrode 8 are each connected to a power source 7, and a voltage V1 is applied to the electron-emitting device 1 and a voltage V2 is applied to the counter electrode 8. Such an experimental system was placed in a vacuum, and V1 was raised stepwise to conduct an electron emission experiment. In each experiment, the distance between the electron-emitting device and the counter electrode was 5 mm across the insulator spacer 9. Moreover, it measured by the applied voltage V2 = 50V to a counter electrode.

Example 1
3 mL of ethanol solvent as a dispersion solvent is put in a reagent bottle, and 0.5 g of spherical silica particles (average particle size 110 nm) are charged as insulator fine particles 5 in the reagent bottle. Was made.

  In addition, as a conductive fine particle dispersion in which conductive fine particles 6 are dispersed in a dispersion solvent, a silver nanoparticle colloid liquid manufactured by Applied Nanoparticles Laboratory (a hexane dispersion having an average particle diameter of silver fine particles of 4.5 nm and a fine particle solid concentration of 10% Solution) was prepared.

  Next, on the 30 mm square SUS substrate to be the electrode substrate 2, the conductive fine particle layer is formed by repeating the application of the conductive fine particle dispersion by rotating at 500 rpm for 10 seconds using a spin coating method. Deposited. This was naturally dried.

  Next, the electron acceleration layer 4 was formed by repeating applying the silica particle dispersion on the conductive fine particle layer by rotating it at 3000 rpm for 10 seconds twice. Then, it was dried until the solvent was completely volatilized at room temperature.

An electron-emitting device of Example 1 was obtained by forming the thin film electrode 3 on the surface of the electron acceleration layer 4 thus formed by using a magnetron sputtering apparatus. Gold was used as a film forming material for the thin film electrode 3, the layer thickness of the thin film electrode 3 was 40 nm, and the area was 0.014 cm ² .

When the electron emission current of the electron-emitting device of this example was measured, the electron emission current was 0.2 mA / cm ² at a voltage of V1 = 15 V applied to the thin film electrode 3 in a vacuum of 1 × 10 ⁻⁸ ATM. Met.

  Further, the electron acceleration layer of the electron-emitting device of this example was embedded in an epoxy resin, and the thin film electrode and the electron acceleration layer were peeled off from the SUS substrate, which was an electrode substrate. The resin in which the thin film electrode and the electron acceleration layer were embedded was made into a thin slice by a microtome, and the cross section of the electron acceleration layer was observed by TEM. As a result, it was confirmed that the conductive fine particles were unevenly distributed on the electrode substrate side. .

(Comparative Example 1)
3 mL of hexane was added to the reagent bottle as a dispersion solvent, and 0.5 g of spherical silica particles (average particle size: 110 nm) were charged therein as insulator fine particles. . Next, 0.125 g (solid content weight) of silver nanoparticle colloid liquid (hexane fine particle average particle diameter 4.5 nm, fine particle solid content concentration 7%) manufactured by Applied Nanoparticles Lab. ) Was added, and ultrasonic dispersion treatment was performed in the same manner to obtain a fine particle mixed dispersion.

  On a 30 mm square SUS substrate to be an electrode substrate, using a spin coat method, after applying for 5 sec at 500 rpm and twice at 3000 rpm for 10 sec, and applying the above fine particle mixed dispersion, An electron acceleration layer was formed.

On the surface of the electron acceleration layer of this comparative example, a thin film electrode was formed using a magnetron sputtering apparatus, whereby the electron-emitting device of comparative example 1 was obtained. Gold was used as the film forming material for the thin film electrode, the layer thickness of the upper electrode was 40 nm, and the area was 0.014 cm ² .

The electron emission current of this comparative example was measured. The electron emission current was 0.02 mA / cm ² at a voltage of 15 V applied to the thin film electrode in a vacuum of 1 × 10 ⁻⁸ ATM. .

  Further, the electron acceleration layer of the electron-emitting device of this comparative example was embedded in an epoxy resin, and the thin film electrode and the electron acceleration layer were peeled off from the substrate. Then, the resin in which the thin film electrode and the electron acceleration layer were embedded was made into a thin slice by a microtome, and the cross section of the electron acceleration layer was observed by TEM. As a result, it was confirmed that the conductive fine particles were dispersed in the electron acceleration layer. It was.

  From the above, the conductive fine particle dispersion is applied, and then the insulating fine particle dispersion is applied to form the electron acceleration layer, whereby the conductive fine particles are unevenly distributed on the electrode substrate side to obtain a larger amount of electron emission. You can see that

[Embodiment 2]
FIG. 4 shows an example of a charging device 90 according to the present invention using the electron emission device 10 according to the present invention described in the first embodiment. The charging device 90 includes an electron-emitting device 10 having the electron-emitting device 1 and a power source 7 that applies a voltage to the electron-emitting device 1, and charges the photoconductor 11. The image forming apparatus according to the present invention includes the charging device 90. In the image forming apparatus according to the present invention, the electron-emitting device 1 constituting the charging device 90 is installed facing the photosensitive member 11 that is a member to be charged, and emits electrons by applying a voltage to the photosensitive member 11. Is charged. In the image forming apparatus according to the present invention, conventionally known members may be used other than the charging device 90. Here, it is preferable that the electron-emitting device 1 used as the charging device 90 is disposed 3 to 5 mm away from the photoreceptor 11, for example. The applied voltage to the electron-emitting device 1 is preferably about 25V, and the electron acceleration layer of the electron-emitting device 1 is configured such that, for example, 1 μA / cm ² of electrons is emitted per unit time when a voltage of 25V is applied. It only has to be.

  The electron emission device 10 used as the charging device 90 is not accompanied by discharge, and therefore no ozone is generated from the charging device 90. Ozone is harmful to the human body and regulated by various environmental standards, and even if it is not released outside the machine, it oxidizes and degrades organic materials such as the photoreceptor 11 and the belt. Such a problem can be solved by using the electron emission device 10 according to the present invention for the charging device 90 and having the charging device 90 in the image forming apparatus. Further, since the electron-emitting device 1 can emit electrons stably and satisfactorily, the charging device 90 can be charged efficiently.

  Further, since the electron emission device 10 used as the charging device 90 is configured as a surface electron source, it can be charged with a width in the rotation direction of the photoconductor 11 and there are many opportunities for charging to a certain place of the photoconductor 11. You can earn. Therefore, the charging device 90 can be uniformly charged as compared with a wire charger that charges in a linear manner. Further, the charging device 90 has an advantage that the applied voltage can be remarkably reduced to about 10 V as compared with a corona discharger that requires voltage application of several kV.

[Embodiment 3]
FIG. 5 shows an example of an electron beam curing apparatus 100 according to the present invention using the electron emission apparatus 10 according to the present invention described in the first embodiment. The electron beam curing device 100 includes an electron emission device 10 having an electron emission element 1 and a power source 7 that applies a voltage to the electron emission device 1, and an acceleration electrode 21 that accelerates electrons. In the electron beam curing apparatus 100, the electron-emitting device 1 is used as an electron source, and the emitted electrons are accelerated by the acceleration electrode 21 and collide with the resist (cured object) 22. Since the energy required for curing the general resist 22 is 10 eV or less, the acceleration electrode is not necessary if attention is paid only to the energy. However, since the penetration depth of the electron beam is a function of electron energy, for example, an acceleration voltage of about 5 kV is required to cure all the resist 22 having a thickness of 1 μm.

  A conventional general electron beam curing apparatus seals an electron source in a vacuum, emits electrons by applying a high voltage (50 to 100 kV), takes out electrons through an electron window, and irradiates them. With this electron emission method, a large energy loss occurs when transmitting through the electron window. Further, since electrons reaching the resist also have high energy, they pass through the thickness of the resist, resulting in low energy utilization efficiency. Further, since the range that can be irradiated at one time is narrow and drawing is performed in a dot shape, the throughput is also low.

  On the other hand, since the electron-emitting device 1 can emit electrons stably and satisfactorily, the electron beam curing apparatus according to the present invention can irradiate the electron beam efficiently. Further, since the electron transmission window is not passed, there is no energy loss and the applied voltage can be lowered. Further, since it is a surface electron source, the throughput is remarkably increased. Further, if electrons are emitted according to the pattern, maskless exposure can be performed.

[Embodiment 4]
FIGS. 6 to 8 show examples of the self-luminous device according to the present invention using the electron-emitting device 10 according to the present invention described in the first embodiment.

  A self-light-emitting device 31 shown in FIG. 6 includes an electron-emitting device having the electron-emitting device 1 and a power source 7 for applying a voltage to the electron-emitting device 1, and a glass serving as a base material at a position facing away from and The substrate 34, the ITO film 33, and the phosphor 32 include a light emitting unit 36 having a laminated structure.

As the phosphor 32, an electron excitation type material corresponding to red, green, and blue light emission is suitable, for example, Y ₂ O ₃ : Eu for red, (Y, Gd) BO ₃ : Eu, and Zn ₂ SiO for green. ₄ : Mn, BaAl ₁₂ O ₁₉ : Mn, blue, BaMgAl ₁₀ O ₁₇ : Eu ^{2+ and the} like can be used. A phosphor 32 is formed on the surface of the glass substrate 34 on which the ITO film 33 is formed. The thickness of the phosphor 32 is preferably about 1 μm. In addition, the thickness of the ITO film 33 is 150 nm in the present embodiment, as long as the film thickness can ensure conductivity.

  In forming the phosphor 32, it is preferable to prepare a kneaded product of an epoxy resin serving as a binder and finely divided phosphor particles and form the film by a known method such as a bar coater method or a dropping method.

  Here, in order to increase the light emission luminance of the phosphor 32, it is necessary to accelerate the electrons emitted from the electron-emitting device 1 toward the phosphor. In this case, the electrode substrate 2 and the light-emitting portion 36 of the electron-emitting device 1 are used. In order to apply a voltage for forming an electric field for accelerating electrons between the ITO films 33, a power source 35 is preferably provided. At this time, the distance between the phosphor 32 and the electron-emitting device 1 is preferably 0.3 to 1 mm, the applied voltage from the power source 7 is preferably 18 V, and the applied voltage from the power source 35 is preferably 500 to 2000 V.

  A self-luminous device 31 ′ shown in FIG. 7 includes an electron-emitting device 1, a power source 7 that applies a voltage to the electron-emitting device 1, and a phosphor 32. In the self-luminous device 31 ′, the phosphor 32 has a planar shape, and the phosphor 32 is disposed on the surface of the electron-emitting device 1. Here, the phosphor 32 layer formed on the surface of the electron-emitting device 1 is prepared as a coating liquid composed of a kneaded material with the phosphor particles finely divided as described above, and is formed on the surface of the electron-emitting device 1. To do. However, since the electron-emitting device 1 itself has a structure that is weak against external force, there is a risk that the device may be damaged if film forming means by the bar coater method is used. Therefore, a method such as a dropping method or a spin coating method may be used.

  A self-luminous device 31 ″ shown in FIG. 8 includes an electron-emitting device 10 having an electron-emitting device 1 and a power source 7 for applying a voltage to the electron-emitting device 1, and further, as a phosphor 32 ′ on the electron acceleration layer 4 of the electron-emitting device 1. In this case, the fine particles of the phosphor 32 'may be used also as the insulator fine particles 5. However, the above-mentioned phosphor fine particles generally have a low electric resistance, and the insulator fine particles 5 are mixed. Therefore, when the phosphor fine particles are mixed with the insulator fine particles 5 and mixed, the amount of the phosphor fine particles must be kept small, for example, the insulator fine particles 5. When using spherical silica particles (average particle size 110 nm) as the phosphor fine particles and ZnS: Mg (average particle size 500 nm) as the phosphor fine particles, a weight mixing ratio of about 3: 1 is appropriate.

  In the self-emitting devices 31, 31 ′, 31 ″, the electrons emitted from the electron-emitting device 1 collide with the phosphors 32, 32 to emit light. The electron-emitting device 1 can emit electrons stably and satisfactorily. The light emitting devices 31, 31 ′, 31 ″ can emit light efficiently. Note that the self-light emitting devices 31, 31 ', 31' 'can emit light more efficiently if they are vacuum-sealed to increase the electron emission current.

Furthermore, FIG. 9 shows an example of an image display device according to the present invention provided with the self-luminous device according to the present invention. An image display device 140 shown in FIG. 9 includes the self-light emitting device 31 ″ shown in FIG. 8 and a liquid crystal panel 330. In the image display device 140, the self-light emitting device 31 ″ is installed behind the liquid crystal panel 330. And used as a backlight. When used in the image display device 140, the applied voltage to the self-luminous device 31 ″ is preferably 20 to 35 V, and for example, 10 μA / cm ² of electrons are emitted per unit time at this voltage. The distance between the self-light emitting device 31 ″ and the liquid crystal panel 330 is preferably about 0.1 mm.

Further, when the self-luminous device 31 shown in FIG. 6 is used as the image display device according to the present invention, the self-luminous devices 31 are arranged in a matrix, and an image is formed and displayed as an FED by the self-luminous device 31 itself. It can also be a shape. In this case, the applied voltage to the self-luminous device 31 is preferably 20 to 35 V, and it is sufficient that, for example, 10 μA / cm ² of electrons are emitted per unit time at this voltage.

[Embodiment 5]
10 and 11 show examples of the blower device according to the present invention using the electron emission device 10 according to the present invention described in the first embodiment. Below, the case where the air blower concerning this invention is used as a cooling device is demonstrated. However, the use of the blower is not limited to the cooling device.

A blower 150 shown in FIG. 10 includes an electron emission device 10 having an electron emission element 1 and a power source 7 that applies a voltage to the electron emission element 1. In the blower 150, the electron-emitting device 1 emits electrons toward the object 41 to be cooled, which is electrically grounded, thereby generating ion wind to cool the object 41 to be cooled. In the case of cooling, the voltage applied to the electron-emitting device 1 is preferably about 18 V, and it is preferable to emit, for example, 1 μA / cm ² of electrons per unit time at this voltage in the atmosphere.

The blower 160 shown in FIG. 11 is further combined with the blower 150 shown in FIG. The blower 160 shown in FIG. 11 emits electrons toward the cooled object 41 in which the electron-emitting device 1 is electrically grounded, and the blower fan 42 blows air toward the cooled object 41 to generate electrons. Electrons emitted from the emitting element are sent toward the cooled object 41 to generate an ion wind to cool the cooled object 41. In this case, the air volume by the blower fan 42 is preferably 0.9 to ² L / min / cm ² .

  Here, when the object to be cooled 41 is cooled by air blowing, the flow velocity on the surface of the object to be cooled 41 becomes 0 only by air blowing by a fan or the like as in the conventional air blowing device or cooling device, and the most heat is released. The air in the desired part is not replaced and the cooling efficiency is poor. However, when charged particles such as electrons and ions are contained in the air to be blown, when the vicinity of the object to be cooled 41 is approached, it is attracted to the surface of the object to be cooled 41 by electric force. The atmosphere can be changed. Here, in the air blowers 150 and 160 according to the present invention, since the air to be blown contains charged particles such as electrons and ions, the cooling efficiency is remarkably increased. Furthermore, since the electron-emitting device 1 can emit electrons stably and satisfactorily, the air blowers 150 and 160 can be cooled more efficiently.

  The present invention is not limited to the above-described embodiments and examples, and various modifications are possible within the scope of the claims. That is, embodiments obtained by combining technical means appropriately modified within the scope of the claims are also included in the technical scope of the present invention.

  In the method for manufacturing an electron-emitting device according to the present invention, an electron-emitting device that can be easily manufactured in the atmosphere and can emit electrons stably and satisfactorily can be manufactured. Thus, for example, a self-luminous device, an image display device, or emitted electrons are generated by combining with a charging device, an electron beam curing device, or a light emitter of an image forming apparatus such as an electrophotographic copying machine, a printer, or a facsimile. By using the ion wind to be applied, it can be suitably applied to a cooling device or the like.

DESCRIPTION OF SYMBOLS 1 Electron emission element 2 Electrode substrate 3 Thin film electrode 4 Electron acceleration layer 5 Insulator fine particle 6 Conductive fine particle 7 Power supply (power supply part)
8 Counter electrode 9 Insulator spacer 10 Electron emission device 11 Photoreceptor 21 Accelerating electrode 22 Resist (cured object)
31, 31 ', 31 "Self-luminous device 32, 32' Phosphor (light emitter)
33 ITO film 34 Glass substrate 35 Power source 36 Light emitting unit 41 Cooled object 42 Blower fan 90 Charging device 100 Electron beam curing device 140 Image display device 150 Blower device 160 Blower device 330 Liquid crystal panel

Claims (14)

An electrode substrate, a thin film electrode, and an electron acceleration layer between the electrode substrate and the thin film electrode, and when a voltage is applied between the electrode substrate and the thin film electrode, the electron acceleration layer A method of manufacturing an electron-emitting device that accelerates electrons to emit the electrons from the thin-film electrode,
After applying a conductive fine particle dispersion in which conductive fine particles are dispersed in a dispersion solvent on the electrode substrate, an insulating fine particle dispersion in which insulator fine particles having an average particle size larger than that of the conductive fine particles are dispersed in a dispersion solvent A method for manufacturing an electron-emitting device, comprising: an electron acceleration layer forming step of forming the electron acceleration layer by applying a coating.   The method of manufacturing an electron-emitting device according to claim 1, wherein the insulating fine particle dispersion and the conductive fine particle dispersion contain different dispersion solvents.   The method of manufacturing an electron-emitting device according to claim 1 or 2, wherein the conductive fine particles have an average particle size of 3 to 10 nm.   4. The method for manufacturing an electron-emitting device according to claim 1, wherein the insulating fine particles have an average particle size of 10 to 500 nm. 5.   5. The method of manufacturing an electron-emitting device according to claim 1, wherein the conductive fine particle dispersion is a nanocolloid liquid of the conductive fine particles.   An electron-emitting device manufactured by the method for manufacturing an electron-emitting device according to claim 1.   An electron-emitting device, comprising: the electron-emitting device according to claim 6; and a power supply unit that applies a voltage between the electrode substrate and the thin-film electrode included in the electron-emitting device.   A charging device comprising the electron-emitting device according to claim 7, wherein the photosensitive member is charged by emitting electrons from the electron-emitting device.   An image forming apparatus comprising the charging device according to claim 8.   An electron beam curing device comprising the electron emission device according to claim 7, wherein the material to be cured is cured by emitting electrons from the electron emission device.   A self-luminous device comprising the electron-emitting device according to claim 7 and a light emitter, and emitting light from the electron-emitting device to cause the light emitter to emit light.   An image display device comprising the self-luminous device according to claim 11. A blower comprising the electron emission device according to claim 7, wherein electrons are emitted from the electron emission device and blown.   A cooling device comprising the electron-emitting device according to claim 7, wherein electrons are emitted from the electron-emitting device to cool an object to be cooled.

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