JP3737708B2 - Field emission device and image display device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention provides field emissionDevice and field emission deviceThe present invention relates to an image display device configured by using.
[0002]
[Prior art]
  A surface conduction type field emission device used in an image display device is described in detail in, for example, Japanese Patent Application Laid-Open No. 11-287862. For example,FIG.These are sectional drawings which show typically the example of 1 composition of the conventional plane type field emission element.FIG.2, a pair of electrodes (element electrodes) 2 and 3 are provided on the surface of the substrate 1, and a conductive film 4 is formed between the electrodes 2 and 3. A gap portion 5 is formed in the conductive film 4, and the vicinity of the gap portion 5 constitutes an electron emission portion 6.
[0003]
Electron emission from the electron emission portion 6 is caused by a strong electric field in the gap portion caused by voltage application to the opposing device electrodes 2 and 3, and electrons are emitted from one conductive film of the electron emission portion into the vacuum due to the tunnel effect. Is done.
[0004]
However, the emitted electrons proceed along the electric field in the vicinity of the electron emission portion, and most of the electrons are absorbed by the conductive film of the positive electrode facing the electron emission portion, and are provided above the electron emission portion 6. Only some of the electrons drawn by the electric field of the anode (not shown) are effective electron emission. Therefore, the effective electron emission efficiency is as low as about 0.1%, and it has been a big problem to increase it. In addition, an electron source including a plurality of such field emission elements and an image display apparatus including the electron source also have problems such as an increase in driving power and heat generation because the electron emission efficiency of the field emission elements is low. There is a need for improvement.
[0005]
[Problems to be solved by the invention]
  The present invention has been made under the above circumstances and is a field emission exhibiting high electron emission efficiency.Device and field emission device thereofAn image display device that can be operated with low driving power is provided.
[0006]
[Means for Solving the Problems]
  In order to solve the above-described problems, the present invention includes a pair of electrodes disposed on a substrate facing each other, a conductive film provided between the electrodes and having a gap, and formed in the vicinity of the gap. Electron emission partA field emission device comprising: a field emission device having an anode for attracting electrons emitted from the electron emission portion, the field emission device being disposed opposite to the field emission device; A magnetic film having a magnetic field direction as a direction in which the gap extends is disposed between the magnetic films, and the magnetic film generates a magnetic field that applies a force directed to the anode to electrons emitted from the gap. Field emission deviceI will provide a.
[0007]
In the field emission device of the present invention, the magnetic film can have a granular structure in which ferromagnetic particles magnetized in a nonmagnetic material are dispersed.
In this case, the magnetic film can be an insulating magnetic film formed by dispersing ferromagnetic particles magnetized in a nonmagnetic insulator, which is formed between the substrate and the electron emission portion.
[0008]
  The present invention also includes a pair of electrodes disposed on a substrate, a conductive film provided between the electrodes and having a gap, and an electron emission portion formed in the vicinity of the gap.A field emission device comprising: a field emission device having an anode for attracting electrons emitted from the electron emission portion, the field emission device being disposed to face the field emission device; A field emission device characterized in that a magnetic field is magnetized in a direction in which the portion extends and a force acting on the electrons emitted from the gap portion is directed to the anode.I will provide a.
[0009]
  Further, the present invention is characterized in that a plurality of the field emission devices described above are arranged and means for applying an input electric signal to a pair of electrodes of the field emission device.Field emission deviceI will provide a.
[0010]
In this case, a plurality of field emission devices are arranged in a matrix, one electrode of each field emission device is connected to a row wiring, and the other electrode of each field emission device is connected to a column wiring orthogonal to the row wiring. Can be connected to.
[0011]
  Furthermore, the present invention provides a method as described above.Field emission deviceAnd an image display means for displaying an image based on the emission of electrons from the electron emission portion of each field emission device by an input electric signal.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in more detail.
The present invention is characterized in that a magnetic member that generates a static magnetic field that causes a force directed toward the anode to act on the emitted electrons in the vicinity of the electron emitting portion is arranged.
[0013]
As shown in FIG. 2, when a static magnetic field acts on the flow of electrons, Lorentz force acts on the electrons. Therefore, in the present invention, in the gap between the conductive members, the direction of the electron flow from one to the other is perpendicular to the direction of the electron flow, and the direction perpendicular to the direction in which the force is applied to the electron, that is, the direction in which the gap extends. A magnetic field is applied. That is, a magnetic member having such a direction as the magnetic field direction is disposed.
[0014]
In this way, due to the transverse magnetic field orthogonal to the electron flow, the electrons emitted from the electron emission portion act as a force that separates from the electron emission portion, and the anode is not attracted to the conductive film facing the gap portion. The effective electron emission efficiency is increased as the ratio of being attracted by is increased.
[0015]
For example, when the distance of the gap between the electron emitting portions is 10 nm and a voltage of 10 V is applied, electrons in a transverse magnetic field of 1 Tesla (T) are accelerated by a magnetic field equivalent to about 2 V / μm in addition to the electric field in the gap. Receive. Due to this acceleration, electrons are easily attracted to the anode, the number of electrons reaching the anode is increased, and the effective electron emission efficiency is greatly improved to about 1% from the conventional level of about 0.1%. .
[0016]
In order to improve effective electron emission efficiency, electrons move in a vacuum in the vicinity of the electron emission portion, and therefore it is necessary to apply a magnetic field in the vicinity of the electron emission portion.
Since the electron emission portion has a short size of about 100 nm or less, in order to apply a magnetic field to the electron emission portion, the magnetic material is small from about 1 nm to about 100 nm and dispersed in a non-magnetic material to leak the magnetic field, It is desirable to use a so-called granular structure magnetic film that is magnetized in the uniaxial direction. That is, it is desirable to cause such a leakage magnetic field to act on the emitted electrons.
[0017]
As an example of applying a magnetic field to the electron emission portion, the conductive film can be a magnetic film having a granular structure, and the magnetic field by the magnetic film can be applied. In this case, the magnetic film can be a conductive magnetic film in which minute ferromagnetic particles are dispersed in a nonmagnetic conductor made of a metal such as Al, Cu, Ti, Ta, or Nb.
[0018]
It is also possible to dispose an electron emission portion on an insulating magnetic film having a granular structure disposed on the substrate and to apply a magnetic field by the magnetic film. The insulating magnetic film having a granular structure can have a structure in which minute ferromagnetic particles are dispersed in an insulator such as silicon oxide, magnesium oxide, aluminum oxide, or silicon nitride.
[0019]
Examples of ferromagnetic materials used include Co-Fe, Cr-Fe, Fe-Ni, Fe-Mn, Fe-V, Fe-N, Fe-Nd-B, Sm-Co, Sm-Fe-Zr, Mn-Pt, Co-Pt, Co-Pd, Fe-Pd, Fe-Rh, Ni-Pd, Ni-Pt, Mn-, which are magnetic alloys of noble metals and transition metals, such as Sm-Fe-Zr-N Ir etc. can be mentioned.
[0020]
With the field emission device of the present invention configured as described above, the electron emission efficiency can be greatly improved. An electron source in which a large number of such field emission devices are arranged, and such an electron source are provided. According to the image forming apparatus configured to be used, driving with low driving power is possible.
[0021]
Embodiments of the present invention will be described below with reference to the drawings.
[0022]
FIG. 1 is a schematic diagram showing a configuration example of a field emission device according to the first embodiment of the present invention. In FIG. 1, an insulating magnetic film 11 having a granular structure is formed on the surface of a substrate 1, and a pair of electrodes (element electrodes) 2 and 3 are provided on the magnetic film 11. A conductive film 4 is formed between the electrodes 2 and 3. In the conductive film 4, a gap portion 5 extending in the vertical direction from the paper surface is formed, and the vicinity of the gap portion 5 constitutes an electron emission portion 6.
[0023]
As the substrate 1, a glass or Si substrate can be usually used. Examples of the glass include borosilicate glass and blue plate glass, and a glass substrate in which a silicon oxide film or a silicon nitride film is formed on the glass surface is suitable.
[0024]
The insulating magnetic film having a granular structure formed on the substrate 1 is formed by dispersing ferromagnetic particles in an insulating material. Examples of ferromagnetic materials include Co—Fe, Cr—Fe, and Fe. -Ni, Fe-Mn, Fe-V, Fe-N, Fe-Nd-B, Sm-Co, Sm-Fe-Zr, Sm-Fe-Zr-N, or a magnetic alloy of noble metal and transition metal Certain Mn—Pt, Co—Pt, Co—Pd, Fe—Pd, Fe—Rh, Ni—Pd, Ni—Pt, Mn—Ir, and the like can be used.
[0025]
The insulating magnetic film having a granular structure can be formed by, for example, sputtering. For example, an insulating magnetic film in which minute ferromagnetic particles are dispersed in a silicon oxide film can be obtained by using silicon oxide and a ferromagnetic material as a sputtering target and sputtering them simultaneously or alternately.
The film thickness of the insulating magnetic film is usually 1-1000 nm, preferably 10-100 nm. If the film thickness of the magnetic film is too thin, the magnetic field is insufficient to perform a desired action on the flow of electrons, and if it is too thick, the effect is not so much obtained. The size of the ferromagnetic particles is usually preferably 1/8 to 1/2 of the thickness of the magnetic film.
[0026]
The size of the ferromagnetic particles in the silicon oxide can be changed by adjusting the sputtering power, the substrate temperature, the substrate bias, and the like. For example, a soda-lime glass substrate with a silicon oxide film formed on the surface is used as the substrate 1 and SiO 2 is used as the sputtering target.₂, And CoPt, RF sputtering power 2 W / cm², Substrate temperature 150 ° C., substrate bias 0.2 W / cm²Then, by sputtering for 2 minutes, CoPt particles having a particle size of 10 nm are converted into SiO.₂20 nm thick granular structure CoPt-SiO dispersed in the film₂A magnetic film can be obtained.
[0027]
Thereafter, the insulating magnetic film is magnetized in the uniaxial direction. The magnetic flux density is, for example, about 1 Tesla. However, since the magnetic film is set as thin as about 20 nm, the magnetic field is so weak that it cannot be detected at a distance of several centimeters from the substrate even after magnetization. This magnetic film may be a multilayer film having a two-layer structure as necessary in consideration of adhesion, reliability, and the like.
[0028]
As a material constituting the element electrodes 2 and 3 arranged opposite to each other on the insulating magnetic film 11, a general conductive material can be used. For example, metals or alloys such as Cr, Cu, Ir, Mo, Pd, Pt, Ti, Ta, W, Zr, and PdO, SnO₂, RuO₂Etc. can be selected as appropriate.
[0029]
The distance L1 between the device electrodes 2 and 3 is normally set in the range of several hundred nm to several tens of μm in consideration of the voltage applied between the device electrodes 2 and 3. The length W of the device electrodes 2 and 3 (dimension in the direction perpendicular to the paper surface: not shown) is set in the range of several μm to several hundred μm in consideration of the resistance value of the electrodes and the electron emission characteristics. The The film thickness d of the device electrodes 2 and 3 is usually set in the range of several tens of nm to several μm.
[0030]
The conductive film 4 formed between the device electrodes 2 and 3 is formed by a droplet method, a vacuum deposition method, a printing method, or the like, and the film thickness is usually in a range of several tens to several hundreds of nm. A film is formed.
[0031]
The conductive film 4 may be a single layer or may have a multilayer structure such as a two-layer laminated structure made of two kinds of materials in consideration of reliability and the like. These materials are determined in consideration of good electron emission characteristics, sufficient durability, ease of device fabrication, and the like. Further, the film thickness of the conductive film 4 is appropriately set in consideration of the step coverage to the device electrodes 2 and 3, the resistance value between the device electrodes 2 and 3, and the like. It is preferable to be in the range.
[0032]
Specific materials for forming the conductive film 4 include, for example, PdO and SnO.₂, In₂O_Three-Sb₂O_ThreeAnd the like, metals such as Pd, Pt, Cr, Ti, Cu, Ta, and W, semiconductors such as Si, carbon, and the like can be used, and they can be used in appropriate combinations. The conductive film 4 and the device electrodes 2 and 3 can be made of the same material.
[0033]
The gap 5 formed in the conductive film 4 is formed by a microfabrication technique such as forming by energization or a focused ion beam technique. It is desirable to process the gap L2 of the gap 5 so as to be 100 nm or less. When the distance L2 between the gaps 5 exceeds 100 nm, it is difficult to obtain highly efficient and uniform electron emission characteristics.
[0034]
In order to increase electron emission, the electron emission part 6 is normally subjected to an activation process described later. In addition, conductive fine particles having a particle diameter in the range of several tens to several tens of nanometers may be present inside the electron emission portion 6. The conductive fine particles contain part or all of the elements of the material constituting the conductive film 4.
[0035]
There are various methods for manufacturing a field emission device having the above-described configuration. One example will be described below with reference to FIG.
[0036]
First, after sufficiently cleaning the substrate 1, as shown in FIG. 3A, an insulating magnetic material 11 is deposited by sputtering or the like. The insulating magnetic body 11 is patterned using, for example, a photolithography technique depending on the application.
[0037]
Next, after depositing an element electrode material by a vacuum evaporation method or a sputtering method, the substrate is patterned using, for example, a photolithography technique, and a substrate on which an insulating magnetic body 11 is formed as shown in FIG. Element electrodes 2 and 3 are formed on 1.
[0038]
Next, a first metal, such as Cr, is applied to the substrate 1 provided with the insulating magnetic body 11 and the element electrodes 2 and 3 by a vacuum deposition method or the like so as to improve the adhesion and prevent the droplet from spreading. And deposited to a thickness of 0.5 nm. Then, the first conductive film 12 is formed by patterning the metal film by lift-off or etching, as shown in FIG.
[0039]
Thereafter, as shown in FIG. 3 (d), an organic palladium liquid 13 is deposited on the first conductive film 12 by a droplet method, dried and baked, and from PdO as shown in FIG. 3 (e). A second conductive film 14 is formed.
[0040]
Subsequently, by repeating the application of a pulse voltage between the device electrodes 2 and 3 according to the procedure shown below, as shown in FIG. 3F, a gap portion 5 for forming an electron emission portion is formed.
[0041]
Thereafter, a process called an activation process is performed. The activation step is a step of forming an electron emission portion in the gap portion 5 formed in the conductive films 12 and 14 and at least a part of the vicinity thereof in the following procedure.
[0042]
For example, as shown in FIG. 4, the activation step can be performed by arranging an anode above and repeating the application of a pulse between the device electrodes 2 and 3 under vacuum. That is, a pulse is applied between the device electrodes 2 and 3 by a predetermined program, and the device current If and the emission current Ie are remarkably increased to form an electron emission portion. The formation of the gap can be carried out basically in the same manner under an inert atmosphere or vacuum.
[0043]
The end of the activation process can be determined by measuring the device current If and the emission current Ie. The pulse width, pulse interval, pulse peak value, etc. are set as appropriate.
[0044]
The field emission device obtained through the above steps is preferably subjected to a stabilization step. This step is a step of exhausting the organic substance in the vacuum 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, vacuum exhaust apparatuses such as a sorption pump and an ion pump can be used.
[0045]
In the above-described activation process, when an oil diffusion pump or a rotary pump is used as an exhaust device 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 hardly newly deposited.^-8Torr or less is preferable, and more preferably 1 × 10^-TenTorr or less is particularly preferable.
[0046]
Furthermore, when evacuating the inside of the vacuum vessel, it is preferable to heat the entire vacuum vessel so that the organic substance molecules adsorbed on the inner wall of the vacuum vessel and the field emission element can be easily evacuated. The heating condition at this time is 80 to 250 ° C., preferably 150 to 250 ° C., and it is desirable to perform the treatment for as long as possible. However, the heating condition is not particularly limited to this, and the size and shape of the vacuum vessel, This is performed under conditions appropriately selected according to various conditions such as the configuration. The pressure in the vacuum vessel is preferably as low as possible.^-7Torr or less is preferable, and more preferably 1 × 10^-8Torr or less is particularly preferable. Further, when the magnetic material is re-magnetized in the insulating magnetic film having a granular structure, the emission current becomes more stable.
[0047]
The atmosphere at the time of driving 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, the deposition of new carbon or carbon compound can be suppressed, and as a result, the device current If and the emission current Ie are stabilized.
[0048]
The field emission device according to the present embodiment described above has an electron emission efficiency of about 1%, which is a significantly improved electron emission efficiency as compared with the prior art.
[0049]
FIG. 5 is a schematic diagram showing a configuration example of a field emission device according to the second embodiment of the present invention. In this embodiment, a magnetic material is used for the conductive film. In FIG. 5, a pair of electrodes (element electrodes) 2 and 3 are provided on the surface of the substrate 1, and a conductive magnetic film 41 having a granular structure is formed between the element electrodes 2 and 3. . A gap 5 is formed in the conductive magnetic film 41, and the vicinity of the gap 5 constitutes an electron emission portion 6.
[0050]
The materials constituting the substrate 1 and the device electrodes 2 and 3 are the same as those in the first embodiment.
[0051]
The conductive magnetic film 41 is composed of a single layer or multiple layers, and its material is determined in consideration of good electron emission characteristics, sufficient durability, ease of device fabrication, and the like. The film thickness of the conductive magnetic film is appropriately set in consideration of the step coverage to the device electrodes 2 and 3, the resistance value between the device electrodes 2 and 3, etc., but usually several to several hundred nm It is preferable to be in the range.
[0052]
When the conductive magnetic film 4 is composed of two laminated films, the first layer is a conductive film such as Cr, Ti, Cu, Ta, Mo, W, etc., and the second layer is a granular structure. A magnetic film can be used. The conductive magnetic film having a granular structure has a structure in which minute ferromagnetic particles are dispersed in a metal such as Al, Cu, Ti, Nb, and Ta. Examples of the ferromagnetic material include Co-Fe, Cr-Fe, Fe-Ni, Fe-Mn, Fe-V, Fe-N, Fe-Nd-B, Sm-Co, Sm-Fe-Zr, and Sm-Fe. -Mr-Pt, Co-Pt, Co-Pd, Fe-Pd, Fe-Rh, Ni-Pd, Ni-Pt, Mn-Ir, etc., which are magnetic alloys of noble metals and transition metals, etc. Can be used.
[0053]
The conductive magnetic film having a granular structure can be formed by, for example, sputtering. For example, a conductive magnetic film in which minute ferromagnetic particles are dispersed in a metal film can be obtained by using the metal and the ferromagnetic material as a sputtering target and sputtering them simultaneously or alternately.
[0054]
The size of the ferromagnetic particles in the metal can be changed by adjusting the sputtering power, the substrate temperature, the substrate bias, and the like. For example, a soda-lime glass substrate with a silicon oxide film formed on the surface is used as the substrate 1, and a Cu target is used as the sputtering target And PdFe, RF sputtering power of 2 W / cm², Substrate temperature 150 ° C., substrate bias 0.2 W / cm²Then, by sputtering for 0.5 minutes, the granular structure PdFe-Cu with a thickness of 5 nm is obtained. A magnetic film can be obtained.
[0055]
Thereafter, the magnetic film is magnetized in the uniaxial direction. Since the magnetic film is set as thin as about 5 nm, the magnetic field is so weak that it cannot be detected at a distance of several centimeters from the substrate even after magnetization.
[0056]
The method for forming the gap portion 5 in the conductive magnetic film 41, the interval L2 of the gap portion 5, the activation processing procedure for the electron emission portion 6, and the like are the same as in the first embodiment.
[0057]
There are various methods for manufacturing the above-described field emission device, and an example thereof will be described below with reference to FIG.
[0058]
First, after the substrate 1 is sufficiently cleaned, an element electrode material is deposited by a vacuum deposition method, a sputtering method, or the like, and then is formed on the substrate 1 by using, for example, a photolithography technique as shown in FIG. Element electrodes 2 and 3 are formed.
[0059]
Next, the first conductive film 51 and the granular structure magnetic film 52 are deposited on the substrate 1 provided with the device electrodes 2 and 3 by vacuum deposition or sputtering, and these are patterned using lift-off, etching, or the like, By magnetizing, a conductive magnetic film 41 is formed as shown in FIG.
[0060]
Next, the formation of the gap for forming the electron emission portion, the activation process, and the stabilization process are performed. These processes can be performed by the same procedure as in the first embodiment.
[0061]
As described above, a field emission device with improved electron emission efficiency can be obtained as in the first embodiment. That is, the field emission device according to this embodiment has an electron emission efficiency of about 1%, which is a significantly improved electron emission efficiency as compared with the related art.
[0062]
An electron source can be configured by arranging a plurality of the field emission devices described above. Hereinafter, an electron source in which a plurality of field emission devices are arranged will be described.
[0063]
Various formats can be adopted for the arrangement of the field emission elements. As an example, a plurality of field emission devices are arranged in a matrix in the X direction and the Y direction, and one of the electrodes of the plurality of field emission devices arranged in the same row is commonly connected to the X direction wiring, and the same column The other of the electrodes of the plurality of field emission elements arranged in the can be connected in common 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.
[0064]
The field emission device of the present invention has three characteristics as described above. That is, the emitted electrons from the field emission 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 field emission elements are arranged, if a pulse voltage is appropriately applied to each element, the field emission element is selected and the amount of electron emission is controlled according to the input signal. be able to.
[0065]
Based on this principle, an electron source substrate obtained by arranging a plurality of field emission devices of the present invention will be described below with reference to FIG. In FIG. 7, on the electron source substrate 61, a number of field emission elements 64 are arranged in a matrix pattern. Reference numeral 62 denotes an X direction wiring, 63 denotes a Y direction wiring, and 65 denotes a connection.
[0066]
The m X-direction wirings 62 are made of Dx1, Dx2,..., Dxm, and 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 material, film thickness, and width of the wiring can be selected as appropriate. The Y-direction wiring 63 includes n wirings Dy1, Dy2,..., Dyn, and is formed in the same manner as the X-direction wiring 62. An interlayer insulating layer (not shown) is provided between the m X-direction wirings 62 and the n Y-direction wirings 63, and both are electrically separated.
[0067]
The interlayer insulating layer is made of SiO formed by vacuum deposition, printing, sputtering, etc.₂Etc. can be configured. For example, the interlayer insulating layer is formed in a desired shape on the entire surface or a part of the substrate 61 on which the X-direction wiring 62 is formed, and in particular, can withstand the potential difference at the intersection of the X-direction wiring 62 and the Y-direction wiring 63. In addition, the film thickness, material, and manufacturing method are appropriately selected. The X direction wiring 62 and the Y direction wiring 63 are drawn out as external terminals, respectively.
[0068]
A pair of device electrodes (not shown) constituting the field emission device 64 are electrically connected to the m X-direction wirings 62 and the n Y-direction wirings 63, respectively, by a connection 65 made of a conductive metal or the like. ing.
[0069]
The material constituting the wiring 62 and the wiring 63, the material constituting the connection 65, and the material constituting the pair of element electrodes may be the same or partially different from each other in the constituent elements. These materials are appropriately selected from, for example, the above-described element electrode materials. When the material constituting the element electrode and the wiring material are the same, the wiring connected to the element electrode can also be called an element electrode.
[0070]
Connected to the X direction wiring 62 is an X direction scanning signal applying means 66 for applying a scanning signal for selecting a row of the field emission elements 64 arranged in the X direction. On the other hand, the Y-direction wiring 63 is connected to a modulation signal generating means 67 and a Y-direction scanning means 68 for modulating each column of the field emission elements 64 arranged in the Y direction according to an input signal. The driving voltage applied to each field emission device is supplied as a difference voltage between the scanning signal and the modulation signal applied to the device.
[0071]
Using the simple matrix wiring configured as described above, individual elements can be selected and driven independently.
[0072]
Next, an image forming apparatus configured using such an electron source having a simple matrix arrangement will be described with reference to FIG. FIG. 8 is a schematic diagram illustrating an example of a display panel of the image forming apparatus.
[0073]
In FIG. 8, an insulating magnetic film 72 is formed on an electron source substrate 71 that also serves as a rear plate, and a plurality of field emission elements 73 are arranged on the insulating magnetic film 72. Since the field emission element 73 is formed on the insulating magnetic body 72, the electrons emitted into the vacuum are effectively attracted to the fluorescent film 75 as the anode by the action of the electric field and the magnetic field.
[0074]
Reference numeral 74 denotes a face plate in which a fluorescent film 75, a metal pack 76, and the like are formed on the inner surface of a glass substrate. The face plate 74 includes a fluorescent film 75 that generates light in response to an electron beam to form an image, and a high-voltage terminal 77 that applies a voltage for attracting the electron beam. Reference numeral 78 indicates a support frame, and a rear plate 71 and a face plate 74 are connected to the support frame 78 using frit glass or the like. For example, the rear plate 71 and the face plate 74 are sealed and connected to the support frame 78 by baking for 10 minutes or more in the temperature range of 400 to 500 ° C. in the air or nitrogen, and the display panel is configured.
[0075]
Reference numerals 79 and 80 denote an X-direction wiring and a Y-direction wiring connected to a pair of device electrodes of the surface conduction type field emission device, respectively.
[0076]
The face plate 74, the support frame 78, the rear plate 71, and the like constitute an envelope. It is to be noted that an envelope having sufficient strength against atmospheric pressure can be configured by installing a support body 81 called a spacer between the face plate 74 and the rear plate 71.
[0077]
In the case of monochrome, the fluorescent film 75 can be composed of only a phosphor. In the case of color display, the phosphor film 75 can be composed of a black conductor called a black stripe or a black matrix and a phosphor depending on the arrangement of the phosphors. The purpose of providing a black stripe and a black matrix is to make the mixed colors and the like inconspicuous by making the coating portion between the fluorescent films 75 of the three primary color phosphors necessary in the case of color display black. The purpose is to suppress a decrease in contrast due to external light reflection.
[0078]
A metal pack 76 is usually provided on the inner surface side of the fluorescent film 75. The purpose of providing the metal pack 76 is to improve the luminance by specularly reflecting the light emitted from the phosphor toward the inner surface to the face plate 74 side, and the high voltage terminal 77 as an electrode for applying an electron beam acceleration voltage. And protecting the phosphor from damage caused by collision of negative ions generated in the envelope. In the metal pack 76, after the phosphor film 75 is produced, the inner surface of the phosphor film is smoothed (usually called “filming”), and then Al is deposited by vacuum evaporation or the like. Can be produced.
[0079]
When performing the sealing by firing described above, in the case of color display, it is necessary to correspond each color phosphor to the field emission device, and therefore, sufficient alignment is performed so as not to cause displacement even at high temperatures. Is desirable.
[0080]
According to the image display device configured as described above, since an electron-emitting device having good electron emission efficiency is used, it is possible to display an image with low driving power and without generating much heat. It is.
[0081]
【The invention's effect】
  As described in detail above, the field emission of the present inventionAccording to the device, field emission elementsSince a magnetic member that applies a static magnetic field to the emitted electrons is disposed in the vicinity of the electron emitting portion, the electron emission efficiency can be greatly improved. Also such field emissionWith equipmentAccording to the constructed image display device, driving with low driving power is possible.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view schematically showing a field emission device according to an embodiment of the present invention.
FIG. 2 is a schematic diagram illustrating a force acting on emitted electrons.
FIG. 3 is a cross-sectional view illustrating a method for manufacturing a field emission device according to an embodiment of the present invention in the order of steps.
FIG. 4 is a schematic diagram illustrating a gap portion of a field emission device and an activation process.
FIG. 5 is a cross-sectional view schematically showing a field emission device according to another embodiment of the present invention.
FIG. 6 is a cross-sectional view showing a method of manufacturing a field emission device according to another embodiment of the present invention in the order of steps.
FIG. 7 is a diagram for explaining an example of an electron source and an outline of a driving method according to the present invention.
FIG. 8 is a schematic diagram showing an example of an image display device according to the present invention.
FIG. 9 is a cross-sectional view schematically showing an example of a conventional field emission device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Substrate, 2, 3 ... Electrode, 4 ... Conductive film, 5 ... Gap part, 6 ... Electron emission part, 11 ... Insulating magnetic film, 12 ... First conductive film, 13 ... Organometallic, 14 ... Second conductive film, 41 ... conductive magnetic film, 51 ... first conductive film, 52 ... conductive magnetic film, 61 ... electron source substrate, 62 ... x-direction wiring, 63 ... y-direction wiring, 64 ... Field emission element, 65 ... connection, 66 ... x-direction scanning signal applying means, 67 ... modulation signal generating means, 68 ... y-direction scanning signal applying means, 71 ... electron source substrate, 72 ... insulating magnetic film, 73 ... electron emission Element 74 74 Face plate 75 Phosphor film 76 Metal pack 77 High voltage terminal 78 Support frame 79 X-direction wiring 80 Y-direction wiring 81 Support

Claims (7)

A pair of electrodes arranged opposite to each other on the substrate, a conductive film provided between the electrodes and having a gap portion, a field emission device having an electron emission portion formed in the vicinity of the gap portion , and
An anode that is disposed to face the field emission device and that attracts electrons emitted from the electron emission portion.
A field emission device comprising:
A magnetic film having a magnetic field direction as a direction in which the gap extends extends between the substrate and the conductive film, and the magnetic film acts on electrons emitted from the gap toward the anode. A field emission device characterized by generating a magnetic field. 2. The electric field according to claim 1, wherein the magnetic film is formed between the substrate and the electron-emitting portion, and ferromagnetic particles magnetized in a nonmagnetic insulator are dispersed. Ejection device . A pair of electrodes arranged opposite to each other on the substrate, a conductive film provided between the electrodes and having a gap portion, a field emission device having an electron emission portion formed in the vicinity of the gap portion , and
An anode that is disposed to face the field emission device and that attracts electrons emitted from the electron emission portion.
A field emission device comprising:
The field emission device according to claim 1, wherein the conductive film is magnetized in a direction in which the gap portion extends, and generates a magnetic field that applies a force directed to the anode to electrons emitted from the gap portion. 2. The field emission device according to claim 1, wherein the magnetic film has a granular structure in which ferromagnetic particles magnetized in a nonmagnetic material are dispersed. The field emission device are plural arranged, field emission device according to claim 1 or 3, characterized in that it comprises means for applying an input electrical signal to the pair of electrodes of the field emission device. The plurality of field emission devices are arranged in a matrix, one electrode of each field emission device is connected to a row wiring, and the other electrode of each field emission device is connected to a column wiring orthogonal to the row wiring. The field emission device according to claim 5, wherein the field emission device is connected . The field emission device according to claim 5, and image display means for displaying an image based on the emission of electrons from the electron emission portion of each field emission device by the input electric signal. An image display device.

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