JP3839792B2 - Electron emission method of electron-emitting device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electron emission method for an electron emission element having a first electrode and a second electrode formed in an emitter section.
[0002]
[Prior art]
Recently, an electron-emitting device has a cathode electrode and an anode electrode, and is applied to various applications such as a field emission display (FED) and a backlight. When applied to the FED, a plurality of electron-emitting devices are two-dimensionally arranged, and a plurality of phosphors corresponding to these electron-emitting devices are respectively arranged at a predetermined interval.
[0003]
As conventional examples of this electron-emitting device, there are, for example, Patent Documents 1 to 5, but none of them uses a dielectric in the emitter portion, so that forming processing or fine processing is required between the opposing electrodes, or electron emission is performed. For this reason, a high voltage must be applied, and the panel manufacturing process is complicated and the manufacturing cost is high.
[0004]
Therefore, it is considered that the emitter portion is made of a dielectric, but various theories are described in the following Non-Patent Documents 1 to 3 as electron emission from the dielectric.
[0005]
[Patent Document 1]
JP-A-1-315333
[Patent Document 2]
JP 7-147131 A
[Patent Document 3]
JP 2000-285801 A
[Patent Document 4]
Japanese Patent Publication No.46-20944
[Patent Document 5]
Japanese Examined Patent Publication No. 44-26125
[Non-Patent Document 1]
Yasuoka, Ishii, "Pulsed electron source using a ferroelectric cathode" Applied Physics Vol.68, No.5, p546-550 (1999)
[Non-Patent Document 2]
V.F.Puchkarev, G.A.Mesyats, On the mechanism of emission from the ferroelectric ceramic cathode, J.Appl.Phys., Vol. 78, No. 9, 1 November, 1995, p. 5633-5637
[Non-Patent Document 3]
H.Riege, Electron emission ferroelectrics-a review, Nucl. Instr. And Meth. A340, p. 80-89 (1994)
[0006]
[Problems to be solved by the invention]
In the conventional electron-emitting device described above, electrons constrained by the surface of the dielectric, the interface between the dielectric and the upper electrode, and the defect level inside the dielectric are emitted by the polarization inversion of the dielectric. That is, as long as polarization reversal occurs in the dielectric, the amount of emitted electrons is almost constant regardless of the voltage level of the applied voltage pulse.
[0007]
However, there is a problem that the electron emission is not stable, the number of electron emission is up to about tens of thousands, and the practicality is poor. As described above, conventionally, an effect of an electron-emitting device having an emitter portion made of a dielectric material has not been found.
[0008]
Moreover, there has been no search for electron emission characteristics by material, such as when the emitter portion is made of a piezoelectric material, made of an antiferroelectric material, or made of an electrostrictive material.
[0009]
The present invention is capable of efficiently emitting electrons to an electron-emitting device having an emitter portion made of a piezoelectric material, and facilitating application to a display, a light source, and the like. An object of the present invention is to provide an electron emission method.
[0010]
Another object of the present invention is to allow an electron-emitting device having an emitter portion made of an antiferroelectric material to efficiently emit electrons, and can be applied to displays, light sources, and the like. An object of the present invention is to provide an electron emission method for an electron-emitting device that can be facilitated.
[0011]
Another object of the present invention is to make it possible to efficiently emit electrons to an electron-emitting device having an emitter portion made of an electrostrictive material, so that it can be easily applied to displays and light sources. It is an object of the present invention to provide an electron emission method for an electron emission device.
[0012]
[Means for Solving the Problems]
  An electron emission method for an electron-emitting device according to the present invention includes an emitter section made of an electrostrictive material, and a first electrode and a second electrode formed in contact with the emitter section.AndElectrons are emitted by applying an electric field to the emitter through the first and second electrodes to control the amount of polarization in the emitter.RudenElectron emission method for child-emitting deviceAnd, by applying the electric field between the first electrode and the second electrode, at least a part of the emitter section undergoes polarization inversion or polarization change, and the polarization inversion or polarization change causes the first inversion. Since the positive electrode side of the dipole moment is arranged around one electrode, primary electrons are extracted from the first electrode, and the primary electrons extracted from the first electrode collide with the emitter section. Secondary electrons are emitted from the emitter.It is characterized by that.
[0035]
In this case, since the polarization at the emitter portion occurs diffusely according to the change in the electric field, the amount of electron emission increases as the amount of polarization per unit time increases. That is, by controlling the amount of polarization in the emitter section, electrons can be efficiently emitted, so that application to a display, a light source, or the like can be facilitated.
[0036]
  In the present invention, in the first period, a first voltage in which the potential of the first electrode is higher than the potential of the second electrode is applied between the first electrode and the second electrode. The emitter is polarized in one direction in advance, and a second voltage lower than the potential of the second electrode is applied to the first electrode and the first electrode in the second period. The electrons may be emitted between the two electrodes by changing the polarization of the emitter section.Yes.
[0037]
  Also,In the first period, Between the first electrode and the second electrodeThe first voltage to be applied is set to 0 V, and the emitter section is previously unpolarized.In the second period, a second voltage in which the potential of the first electrode is lower than the potential of the second electrode is applied between the first electrode and the second electrode, Electrons are emitted by changing the polarization of the emitter.May be. Thereby, in the second period, it is possible to emit electrons by one-sided polarity driving. This leads to simplification of the drive circuit system, which is advantageous in terms of low power consumption, low cost, and downsizing of the structure.
[0038]
  Further, the amount of electron emission may be controlled by controlling the level of the second voltage to control the amount of polarization of the emitter that occurs within a certain time from the start of the second period.Yes.
[0039]
In this case, the level control of the second voltage is, for example, controlling the maximum amplitude and the deviation time of the second voltage if the second voltage is pulsed and the falling edge is ramped. If the second voltage is a rectangular pulse, only the maximum amplitude is controlled. The fixed time is preferably within 10 msec, more preferably within 10 μsec.
[0040]
  In addition, after the electron emission, the second voltage applied at the start time of the second period so that the sustained electron emission occurs due to the slight vibration of the voltage between the first electrode and the second electrode. You may want to control the voltage level ofYes.
[0041]
Since the polarization of the electrostrictive material occurs diffusely according to the change of the electric field, as described above, the amount of electron emission increases as the amount of polarization per unit time increases. Further, the potential difference between the voltage level at which electrons are emitted and the voltage level at which polarization is reset (threshold level) is small.
[0042]
Therefore, once electrons are emitted and the voltage between the first electrode and the second electrode drops, the polarization of the emitter portion is easily reset, and a state in which pseudo 0V is applied is obtained.
[0043]
However, in this second period, since the second voltage is applied between the first electrode and the second electrode, the voltage between the first electrode and the second electrode rapidly increases, Polarization is performed again. At this time, since the polarization changes rapidly, electrons are emitted at a voltage lower than the voltage at the time of the first electron emission.
[0044]
When the second electron emission is performed and the voltage between the first electrode and the second electrode drops, the polarization of the emitter portion is easily reset again, and then between the first electrode and the second electrode. When the second voltage is continuously applied, the voltage between the first electrode and the second electrode is increased again, and polarization is performed. Also in this case, since the change of polarization proceeds rapidly, the electron emission is performed at the same voltage as the voltage at the second electron emission.
[0045]
That is, by controlling the level of the second voltage applied during the second period, the voltage between the first electrode and the second electrode slightly fluctuates, and the electron emission is sustained by this slight vibration. Can be realized. That is, in the second period, it is possible to emit electrons by one-sided polarity driving. This leads to simplification of the drive circuit system, which is advantageous in terms of low power consumption, low cost, and downsizing of the structure.
[0046]
  In each of the above-described inventions, the first electrode is formed in contact with the emitter portion, the second electrode is formed in contact with the emitter portion, and a slit is formed together with the first electrode. You can do itYes.In this case, when the width of the slit is d and the voltage between the first electrode and the second electrode is Vak, an electric field E applied to the emitter section and expressed by E = Vak / d Will cause polarization reversal or polarization change.The
[0047]
  In each of the above-described inventions, the first electrode may be formed on the first surface of the emitter portion, and the second electrode may be formed on the second surface of the emitter portion.Yes.In this case, when the thickness of the emitter section sandwiched between the first electrode and the second electrode is h, and the voltage between the first electrode and the second electrode is Vak, the emitter section And polarization inversion or polarization change is performed by the electric field E expressed by E = Vak / h.The
[0048]
  The voltage Vak between the first electrode and the second electrode is preferably less than the dielectric breakdown voltage of the emitter section.Yes.
  The electron emission method of the electron-emitting device according to the present invention includes an emitter portion made of an electrostrictive material, and a first electrode and a second electrode formed in contact with the emitter portion, An electron emission method for an electron-emitting device that emits electrons by applying an electric field to the emitter section through the first and second electrodes to control a polarization amount in the emitter section, wherein And applying a first voltage between the first electrode and the second electrode so that the potential of the first electrode is higher than the potential of the second electrode, so that the emitter section is preliminarily set in one direction. Applying a second voltage between the first electrode and the second electrode, wherein the second voltage is lower than the potential of the second electrode in the second period; Electrons are emitted by changing the polarization of the emitter, and after the electron emission, Controlling the level of the second voltage applied at the start of the second period so that sustained electron emission occurs due to the slight vibration of the voltage between the first electrode and the second electrode. Features.
[0049]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of an electron emission method for an electron-emitting device according to the present invention will be described below with reference to FIGS.
[0050]
First, the electron-emitting device according to the present embodiment can be applied not only as a display, but also to an electron beam irradiation device, a light source, an alternative use of LED, and an electronic component manufacturing apparatus.
[0051]
The electron beam in the electron beam irradiation apparatus has high energy and excellent absorption performance as compared with the ultraviolet light in the currently widely used ultraviolet irradiation apparatus. As application examples, in semiconductor devices, there are uses for solidifying insulating films when stacking wafers, uses for curing printing inks uniformly when printing is dried, and uses for sterilizing medical devices in packages. .
[0052]
The use as a light source is for high luminance and high efficiency specifications, for example, a light source use of a projector in which an ultra-high pressure mercury lamp or the like is used. When the electron-emitting device according to this embodiment is applied to a light source, it has characteristics of downsizing, long life, high-speed lighting, and reduction of environmental load due to mercury-free.
[0053]
Alternative uses of LEDs include surface light source applications such as indoor lighting, automotive lamps, and traffic lights, and chip light sources, traffic lights, and backlights for small liquid crystal displays for mobile phones.
[0054]
Applications of the electronic component manufacturing apparatus include an electron beam source of a film forming apparatus such as an electron beam vapor deposition apparatus, an electron source for plasma generation (for activation of gas, etc.) in a plasma CVD apparatus, an electron source for gas decomposition application, etc. . There are also vacuum microdevice applications such as tera-Hz driven high-speed switching elements and large current output elements. In addition, it is also preferably used as a printer component, that is, a light emitting device for exposing a photosensitive drum or an electron source for charging a dielectric.
[0055]
As electronic circuit components, a large current output and a high amplification factor are possible, and therefore there are applications to digital elements such as switches, relays, and diodes, and analog elements such as operational amplifiers.
[0056]
As shown in FIG. 1, the electron-emitting device 10 </ b> A according to the first embodiment includes an emitter section 14 formed on the substrate 12 and a first surface formed on one surface of the emitter section 14. It has an electrode (cathode electrode) 16 and a second electrode (anode electrode) 20 that is also formed on one surface of the emitter section 14 and forms a slit 18 together with the cathode electrode 16. A drive voltage Va from the pulse generation source 22 is applied between the cathode electrode 16 and the anode electrode 20 via a resistor R1. In the example of FIG. 1, the anode electrode 20 is connected to GND (ground), and the potential of the anode electrode 20 is set to zero. Of course, a potential other than zero potential may be used. .
[0057]
When this electron-emitting device 10A is used as a display pixel, a third electrode (collector electrode) 24 is disposed above the emitter section 14 at a position facing the slit 18, and the collector electrode 24 Is coated with a phosphor 28. A bias voltage source 102 (bias voltage Vc) is connected to the collector electrode 24 via a resistor R3.
[0058]
In addition, the electron-emitting device 10A according to the first embodiment is naturally disposed in the vacuum space. As shown in FIG. 1, the electron-emitting device 10A has electric field concentration points A and B. The point A includes a triple point where the cathode electrode 16 / emitter portion 14 / vacuum exists at one point. The point B can also be defined as a point including a triple point where the anode electrode 20 / emitter 14 / vacuum exists at one point.
[0059]
And the degree of vacuum in the atmosphere is 10²-10^-6Pa is preferred, more preferably 10^-3-10^-FivePa.
[0060]
The reason for selecting such a range is that in low vacuum, (1): because there are a lot of gas molecules in the space, it is easy to generate plasma, and if too much plasma is generated, a large amount of positive ions are generated in the cathode electrode. There is a possibility of causing damage by colliding with 16 and (2): the emitted electrons collide with gas molecules before reaching the collector electrode 24, and the phosphor 28 is accelerated by electrons sufficiently accelerated at the collector potential (Vc). This is because excitation may not be sufficiently performed.
[0061]
On the other hand, in a high vacuum, electrons are likely to be emitted from the electric field concentration points A and B, but there is a problem in that the structure support and the vacuum seal portion become large, which is disadvantageous for miniaturization.
[0062]
Here, the emitter section 14 is made of a dielectric. As the dielectric, a dielectric having a relatively high relative dielectric constant, for example, 1000 or more can be adopted. In addition to barium titanate, such dielectrics include lead zirconate, lead magnesium niobate, lead nickel niobate, lead zinc niobate, lead manganese niobate, lead magnesium tantalate, lead nickel tantalate, Ceramics containing lead antimony stannate, lead titanate, lead magnesium tungstate, lead cobalt niobate, etc., or any combination thereof, those containing 50% by weight or more of these compounds as the main component, or the ceramics In addition to lanthanum, calcium, strontium, molybdenum, tungsten, barium, niobium, zinc, nickel, manganese and other oxides, or any combination thereof, or those appropriately added with other compounds Can do.
[0063]
For example, in a two-component system nPMN-mPT of lead magnesium niobate (PMN) and lead titanate (PT) (where n and m are mole ratios), increasing the PMN mole ratio decreases the Curie point. Thus, the relative dielectric constant at room temperature can be increased.
[0064]
In particular, when n = 0.85 to 1.0 and m = 1.0−n, the relative dielectric constant is preferably 3000 or more. For example, when n = 0.91 and m = 0.09, a room temperature relative permittivity of 15000 is obtained, and when n = 0.95 and m = 0.05, a room temperature relative permittivity of 20000 is obtained.
[0065]
Next, in the ternary system of lead magnesium niobate (PMN), lead titanate (PT), and lead zirconate (PZ), besides increasing the molar ratio of PMN, tetragonal and pseudocubic or tetragonal crystals And a composition in the vicinity of a morphotropic phase boundary (MPB) of rhombohedral crystals are preferable for increasing the relative dielectric constant. For example, the relative dielectric constant is 5500 when PMN: PT: PZ = 0.375: 0.375: 0.25, and the relative dielectric constant is 4500 when PMN: PT: PZ = 0.5: 0.375: 0.125. Is particularly preferred. Furthermore, it is preferable to improve the dielectric constant by mixing a metal such as platinum into these dielectrics within a range where insulation can be ensured. In this case, for example, 20% by weight of platinum may be mixed in the dielectric.
[0066]
Further, as described above, a piezoelectric / electrostrictive layer, an antiferroelectric layer, or the like can be used for the emitter section 14. When a piezoelectric / electrostrictive layer is used as the emitter section 14, the piezoelectric / electrostrictive layer is used. For example, lead zirconate, lead magnesium niobate, lead nickel niobate, lead zinc niobate, lead manganese niobate, lead magnesium tantalate, lead nickel tantalate, lead antimony stannate, lead titanate, titanate Examples include ceramics containing barium, lead magnesium tungstate, lead cobalt niobate, or the like, or any combination thereof.
[0067]
It goes without saying that the main component may contain 50% by weight or more of these compounds. Among the ceramics, a ceramic containing lead zirconate is most frequently used as a constituent material of the piezoelectric / electrostrictive layer constituting the emitter section 14.
[0068]
Further, when the piezoelectric / electrostrictive layer is composed of ceramics, the ceramics may further include oxides such as lanthanum, calcium, strontium, molybdenum, tungsten, barium, niobium, zinc, nickel, manganese, or any of these. A combination of these or other ceramics appropriately added may be used.
[0069]
For example, it is preferable to use a ceramic containing, as a main component, a component composed of lead magnesium niobate, lead zirconate and lead titanate, and further containing lanthanum or strontium.
[0070]
The piezoelectric / electrostrictive layer may be dense or porous, and in the case of being porous, the porosity is preferably 40% or less.
[0071]
When an antiferroelectric layer is used as the emitter section 14, the antiferroelectric layer is mainly composed of lead zirconate, a component composed of lead zirconate and lead stannate, Furthermore, what added lanthanum oxide to lead zirconate, and what added lead zirconate and lead niobate to the component which consists of lead zirconate and lead stannate are desirable.
[0072]
The antiferroelectric film may be porous. In the case of being porous, the porosity is preferably 30% or less.
[0073]
Further, when strontium bismuthate tantalate is used for the emitter section 14, the polarization inversion fatigue is small and preferable. Such a material with low polarization reversal fatigue is a layered ferroelectric compound, (BiO₂)²⁺(A_m-1B_mO_{3m + 1})^2-It is expressed by the general formula. Here, the ions of metal A are Ca²⁺, Sr²⁺, Ba²⁺, Pb²⁺, Bi³⁺, La³⁺And the ion of metal B is Ti⁴⁺, Ta⁵⁺, Nb⁵⁺Etc.
[0074]
In addition, the sintering temperature can be lowered by mixing the piezoelectric / electrostrictive / antiferroelectric ceramics with a glass component such as lead borosilicate glass and other low melting point compounds (such as bismuth oxide). This is advantageous when the emitter section 14 is formed on the substrate 12.
[0075]
In addition, by using a lead-free material for the emitter portion 14 to make the emitter portion 14 a material having a high melting point or transpiration temperature, it becomes difficult to be damaged by the collision of electrons or ions.
[0076]
As a method of forming the emitter section 14 on the substrate 12, various thick film forming methods such as a screen printing method, a dipping method, a coating method, an electrophoresis method, an ion beam method, a sputtering method, a vacuum evaporation method, Various thin film forming methods such as ion plating, chemical vapor deposition (CVD), and plating can be used.
[0077]
In this embodiment, when forming the emitter section 14 on the substrate 12, a thick film forming method such as a screen printing method, a dipping method, a coating method, or an electrophoresis method is preferably employed.
[0078]
These methods can be formed using pastes or slurries, or suspensions, emulsions, sols, or the like mainly composed of piezoelectric ceramic particles having an average particle diameter of 0.01 to 5 μm, preferably 0.05 to 3 μm. This is because good piezoelectric operation characteristics can be obtained.
[0079]
In particular, the electrophoretic method is capable of forming a film with high density and high shape accuracy, as well as “electrochemistry and industrial physical chemistry Vol. 53, No. 1 (1985), p 63-68 Kazuo Anzai. The authors have the characteristics described in the technical literature such as “Hirotsu” or “The 1st Electrophoresis Method for High-Order Forming of Ceramics Research Discussion (1998), p5-6, p23-24”. Further, a piezoelectric / electrostrictive / antiferroelectric material formed into a sheet shape, a laminate thereof, or a laminate or adhesion of these to another support substrate may be used. As described above, it is preferable to select and use a method as appropriate in consideration of required accuracy and reliability.
[0080]
Here, the size of the width d of the slit 18 between the cathode electrode 16 and the anode electrode 20 will be described. The voltage between the cathode electrode 16 and the anode electrode 20 (the drive voltage Va output from the pulse generation source 22 is the cathode electrode 16). When the voltage between the cathode electrode 16 and the anode electrode 20 is Vak), the polarization inversion is performed by the electric field E represented by E = Vak / d. The width d is preferably set. That is, as the width d of the slit 18 is smaller, polarization inversion can be performed at a lower voltage, and electrons can be emitted by driving at a lower voltage (for example, less than 100 V). Here, the dielectric breakdown voltage of the emitter section 14 is preferably at least 10 kV / mm or more. In this example, when the width d of the slit 18 is 70 μm, for example, even if a drive voltage of −100 V is applied between the cathode electrode 16 and the anode electrode 20, the portion exposed from the slit 18 in the emitter portion 14 is insulated. There is no destruction.
[0081]
The cathode electrode 16 is made of the following material. That is, a conductor having a low sputtering rate and a high evaporation temperature in a vacuum is preferable. For example, Ar⁺The sputtering rate at 600V is 2.0 or less and the vapor pressure is 1.3 × 10^-3A temperature at which Pa becomes 1800 K or more is preferable, and platinum, molybdenum, tungsten, or the like corresponds to this. Also, a conductor having resistance to a high-temperature oxidizing atmosphere, such as a simple metal, an alloy, a mixture of insulating ceramics and a simple metal, a mixture of insulating ceramics and an alloy, etc., preferably platinum, iridium, It is composed of a high melting point noble metal such as palladium, rhodium or molybdenum, an alloy containing silver-palladium, silver-platinum or platinum-palladium as a main component, or a cermet material of platinum and a ceramic material. More preferably, it is made of a material mainly composed of platinum or a platinum-based alloy. Further, carbon and graphite materials such as diamond thin film, diamond-like carbon, and carbon nanotube are also preferably used as the electrode. In addition, about 5-30 volume% is suitable for the ratio of the ceramic material added in electrode material.
[0082]
Furthermore, it is preferable to use a material such as an organometallic paste that can obtain a thin film after firing, such as a platinum resinate paste. Also, oxide electrodes that suppress polarization reversal fatigue, such as ruthenium oxide, iridium oxide, strontium ruthenate, La_1-xSr_xCoO_Three(For example, x = 0.3 or 0.5), La_1-xCa_xMnO_Three, La_1-xCa_xMn_1-yCo_yO_Three(For example, x = 0.2, y = 0.05), or a mixture of these with, for example, a platinum resinate paste is preferable.
[0083]
The cathode electrode 16 is made of the above-described materials using various thick film forming methods such as screen printing, spraying, coating, dipping, coating, and electrophoresis, sputtering, ion beam, vacuum deposition, and ion plating. The film can be formed according to an ordinary film forming method by various thin film forming methods such as chemical vapor deposition (CVD) and plating, and preferably the former thick film forming method. In addition, about the dimension of the cathode electrode 16, as shown in FIG. 2, width W1 was 2 mm and length L1 was 5 mm. The thickness of the cathode electrode 16 is preferably 20 μm or less, and preferably 5 μm or less.
[0084]
The anode electrode 20 is formed by the same material and method as the cathode electrode 16, but is preferably formed by the thick film forming method. The thickness of the anode electrode 20 is also preferably 20 μm or less, and preferably 5 μm or less. As for the dimensions of the anode electrode 20, as shown in FIG. 2, the width W2 was set to 2 mm and the length L2 was set to 5 mm similarly to the cathode electrode 16.
[0085]
The width d of the slit 18 between the cathode electrode 16 and the anode electrode 20 is 70 μm in the present embodiment.
[0086]
In order to electrically separate the wiring electrically connected to the cathode electrode 16 and the wiring electrically connected to the anode electrode 20, the substrate 12 is preferably made of an electrically insulating material.
[0087]
Therefore, the substrate 12 can be made of glass, a high heat-resistant metal, or a material such as enamel whose metal surface is coated with a ceramic material such as glass, but it is optimal to make it with ceramics. .
[0088]
As the ceramic constituting the substrate 12, for example, stabilized zirconium oxide, aluminum oxide, magnesium oxide, titanium oxide, spinel, mullite, aluminum nitride, silicon nitride, glass, a mixture thereof, or the like can be used. Among these, aluminum oxide and stabilized zirconium oxide are preferable from the viewpoint of strength and rigidity. Stabilized zirconium oxide is particularly suitable from the viewpoints of relatively high mechanical strength, relatively high toughness, and relatively small chemical reaction with the cathode electrode 16 and the anode electrode 20. The stabilized zirconium oxide includes stabilized zirconium oxide and partially stabilized zirconium oxide. Stabilized zirconium oxide has a cubic crystal structure or the like and therefore does not cause phase transition.
[0089]
On the other hand, zirconium oxide undergoes a phase transition between a monoclinic crystal and a tetragonal crystal at around 1000 ° C., and cracks may occur during such a phase transition. Stabilized zirconium oxide contains 1 to 30 mol% of a stabilizer such as calcium oxide, magnesium oxide, yttrium oxide, scandium oxide, ytterbium oxide, cerium oxide, and rare earth metal oxides. In order to improve the mechanical strength of the substrate 12, the stabilizer preferably contains yttrium oxide. In this case, yttrium oxide is preferably contained in an amount of 1.5 to 6 mol%, more preferably 2 to 4 mol%, and further preferably 0.1 to 5 mol% of aluminum oxide.
[0090]
The crystal phase can be a cubic + monoclinic mixed phase, a tetragonal + monoclinic mixed phase, a cubic + tetragonal + monoclinic mixed phase, and the like. A phase having a tetragonal crystal or a mixed phase of tetragonal crystal + cubic crystal is optimal from the viewpoint of strength, toughness and durability.
[0091]
When the substrate 12 is made of ceramics, a relatively large number of crystal grains constitute the substrate 12. In order to improve the mechanical strength of the substrate 12, the average grain size of the crystal grains is preferably 0.05. ˜2 μm, more preferably 0.1-1 μm.
[0092]
Each time the emitter part 14, the cathode electrode 16 and the anode electrode 20 are formed, a heat treatment (firing process) can be performed to form an integral structure with the substrate 12, and the emitter part 14, the cathode electrode 16 and the anode electrode 20 can be integrated. After the formation, they can be fired at the same time, and these can be integrally bonded to the substrate 12 at the same time. Depending on the method of forming the cathode electrode 16 and the anode electrode 20, heat treatment (firing treatment) for integration may not be required.
[0093]
The temperature related to the baking treatment for integrating the substrate 12, the emitter section 14, the cathode electrode 16, and the anode electrode 20 is in the range of 500 to 1400 ° C, preferably in the range of 1000 to 1400 ° C. . Further, when the film-shaped emitter portion 14 is heat-treated, it is preferable to perform a baking process while controlling the atmosphere together with the evaporation source of the emitter portion 14 so that the composition of the emitter portion 14 does not become unstable at high temperatures.
[0094]
Alternatively, a method may be employed in which the emitter portion 14 is covered with an appropriate member and fired so that the surface of the emitter portion 14 is not directly exposed to the firing atmosphere. In this case, it is preferable to use the same material as the substrate 12 as the covering member.
[0095]
Next, the principle of electron emission of the electron emitter 10A will be described with reference to FIGS. First, as shown in FIG. 3, the drive voltage Va output from the pulse generation source 22 includes a period during which the first voltage Va1 is output (preparation period T1) and a period during which the second voltage Va2 is output (electronic The release period T2) is one step and the one step is repeated. The first voltage Va1 is a voltage in which the potential of the cathode electrode 16 is higher than the potential of the anode electrode 20, and the second voltage Va2 is a voltage in which the potential of the cathode electrode 16 is lower than the potential of the anode electrode 20. The amplitude Vin of the drive voltage Va can be defined by a value obtained by subtracting the second voltage Va2 from the first voltage Va1 (= Va1-Va2). That is, the waveform of the drive voltage Va is a rectangular pulse of the first voltage Va1 during the preparation period T1 and the second voltage Va2 during the electron emission period T2.
[0096]
As shown in FIG. 4, the preparation period T <b> 1 is a period in which the emitter section 14 is polarized by applying the first voltage Va <b> 1 between the cathode electrode 16 and the anode electrode 20. As the first voltage Va1, a DC voltage may be used as shown in FIG. 3, but one pulse voltage or a pulse voltage may be continuously applied a plurality of times. Here, the preparation period T1 is preferably longer than the electron emission period T2 in order to sufficiently perform the polarization process. For example, the preparation period T1 is preferably 100 μsec or more. This is because the absolute value of the first voltage Va1 for polarization is calculated from the absolute value of the second voltage Va2 for the purpose of preventing power consumption during the application of the first voltage Va1 and damage to the cathode electrode 16. This is because it is set to be small.
[0097]
Further, the first voltage Va1 and the second voltage Va2 are preferably at a voltage level that reliably performs polarization processing with positive and negative polarities. For example, when the dielectric of the emitter section 14 has a coercive voltage, The absolute values of the voltage Va1 and the second voltage Va2 are preferably equal to or greater than the coercive voltage.
[0098]
The electron emission period T2 is a period during which the second voltage Va2 is applied between the cathode electrode 16 and the anode electrode 20. By applying the second voltage Va2 between the cathode electrode 16 and the anode electrode 20, as shown in FIG. 5A, at least a portion of the emitter portion 14 exposed from the slit 18 is inverted. At this time, when the width of the slit is d (see FIG. 1) and the voltage between the cathode electrode 16 and the anode electrode 20 is Vak, it is applied to the emitter section 14 and is expressed by E = Vak / d. Polarization inversion is performed by the electric field E.
[0099]
As a result of this polarization reversal, a local concentrated electric field is generated between the cathode electrode 16 and the positive pole side of the dipole moment in the vicinity thereof, whereby primary electrons are drawn from the cathode electrode 16, and as shown in FIG. Primary electrons extracted from the cathode electrode 16 collide with the emitter section 14, and secondary electrons are emitted from the emitter section 14.
[0100]
When the cathode electrode 16, the emitter section 14, and the vacuum triple point A are provided as in the first embodiment, primary electrons are extracted from the vicinity of the triple point A in the cathode electrode 16, The primary electrons extracted from the triple point A collide with the emitter section 14 and secondary electrons are emitted from the emitter section 14. When the thickness of the cathode electrode 16 is extremely thin (˜10 nm), electrons are emitted from the interface between the cathode electrode 16 and the emitter section 14.
[0101]
Since electrons are emitted according to such a principle, electron emission is stably performed, and the number of electron emission times can be realized over 2 billion times, which is highly practical. In addition, since the amount of emitted electrons increases substantially in proportion to the amplitude Vin of the drive voltage Va applied between the cathode electrode 16 and the anode electrode 20, there is an advantage that the amount of emitted electrons can be easily controlled.
[0102]
Of the emitted secondary electrons, some of the secondary electrons are guided to the collector electrode 24 to excite the phosphor 28 and are realized as phosphor emission outside. Some other secondary electrons and primary electrons are attracted to the anode electrode 20.
[0103]
Here, the emission distribution of secondary electrons will be described. As shown in FIG. 6, the majority of secondary electrons have an energy close to 0, and when emitted from the surface of the emitter section 14 in a vacuum, the secondary electrons move only according to the surrounding electric field distribution. . That is, secondary electrons are accelerated according to the surrounding electric field distribution from a state where the initial velocity is almost 0 (m / sec). For this reason, as shown in FIG. 5B, if an electric field Ea is generated between the emitter section 14 and the collector electrode 24, the emission trajectory of the secondary electrons is determined along the electric field Ea. That is, an electron source with high straightness can be realized. Such secondary electrons with a small initial velocity are electrons in the solid that have gained energy by Coulomb collision of the primary electrons and jumped out of the emitter section 14.
[0104]
Further, the electric field distribution between the emitter section 14 and the collector electrode 24 can be changed by appropriately changing the pattern shape and potential of the collector electrode 24 or by arranging a control electrode (not shown) between the emitter section 14 and the collector electrode 24. By arbitrarily setting, it becomes easy to control the emission trajectory of secondary electrons, and the convergence, expansion, and deformation of the electron beam diameter are also facilitated.
[0105]
The above-described realization of an electron source with high linearity and ease of control of the secondary electron emission trajectory are obtained when the electron-emitting device 10A according to the first embodiment is configured as a pixel of a display. This is advantageous for narrowing the pitch.
[0106]
By the way, as can be seen from FIG.₀Secondary electrons having energy corresponding to are emitted. The secondary electrons are those in which the primary electrons emitted from the cathode electrode 16 are scattered near the surface of the emitter section 14 (reflected electrons).
[0107]
When the cathode electrode 16 is thicker than 10 nm, most of the reflected electrons are directed to the anode electrode 20. The secondary electrons described in this specification are defined to include the reflected electrons and Auger electrons.
[0108]
On the other hand, when the thickness of the cathode electrode 16 is extremely thin (˜10 nm), the primary electrons emitted from the cathode electrode 16 are reflected at the interface between the cathode electrode 16 and the emitter section 14 and travel toward the collector electrode 24. Become.
[0109]
Next, three specific examples of the electron-emitting device 10A according to the first embodiment will be described.
[0110]
In the electron emitter 10Aa according to the first specific example, the constituent material of the emitter section 14 is a piezoelectric material. Other configurations are the same as those of the electron-emitting device 10A according to the first embodiment described above.
[0111]
Here, an electron emission method of the electron emitter 10Aa according to the first specific example will be described.
[0112]
First, as shown in FIG. 7, the polarization-electric field characteristic of the piezoelectric material that is the constituent material of the emitter section 14 draws a hysteresis curve with the electric field E = 0 (V / mm) as a reference.
[0113]
When attention is paid to the curves from the points p1 to p2 to p3 among the hysteresis curves, the piezoelectric material is mostly polarized in one direction at the point p1 to which the positive electric field is applied. Thereafter, when a negative electric field is applied, the polarization starts reversing around the point p2 of the coercive electric field (about −700 V / mm), and all the polarizations are reversed at the point p3.
[0114]
Therefore, in the first specific example, as shown in FIG. 8, first, in the preparation period T1, the first voltage Va1 is applied between the cathode electrode 16 and the anode electrode 20, and the positive electrode with respect to the emitter section 14 is applied. An electric field of about 1000 V / mm is applied. At this time, as can be seen from the polarization-electric field characteristics of FIG. 7, the emitter section 14 is polarized in one direction.
[0115]
Thereafter, in the electron emission period T2 of FIG. 8, the second voltage Va2 is applied between the cathode electrode 16 and the anode electrode 20, and the electric field exceeding the coercive electric field with respect to the emitter section 14 (for example, about −1000 V / mm). ) Is applied, electrons are emitted at a point p4 before reaching the point p3 shown in FIG. As shown in FIG. 8, this is a slight voltage drop at the peak time point P1 of the voltage Vak between the cathode electrode 16 and the anode electrode 20 during a certain time tc1 (here, within 10 μsec) from the start time of the electron emission period T2. It can be seen that electrons are emitted at the peak time P1. That is, current (collector current Ic) rapidly flows through the collector electrode 24 at the peak time point P 1, which indicates that emitted electrons are captured by the collector electrode 24.
[0116]
In this way, by supplying the second voltage Va2 to the cathode electrode 16, secondary electrons are emitted from the emitter section 14 or from the interface between the cathode electrode 16 and the emitter section 14 as described above. It will be.
[0117]
After the electron emission, the voltage Vak between the cathode electrode 16 and the anode electrode 20 is increased again by being pulled by the second voltage Va2 applied to the cathode electrode 16, but the voltage drop at the time of electron emission described above is slight. (Voltage drop level is about 20V), it does not reach the electron emission, and the process ends only with the first electron emission.
[0118]
As described above, in the electron emission method of the electron-emitting device 10Aa according to the first specific example, by efficiently applying an electric field exceeding the coercive electric field to the emitter section 14 polarized in one direction, the electrons can be efficiently generated. Will be released, and application to a display or a light source can be facilitated.
[0119]
The electric field in which electron emission is performed (the electric field at the point p4) is an electric field that exceeds the coercive electric field and almost completes the polarization inversion, and these electric fields are substantially constant. That is, it becomes a digital electron emission characteristic. In addition, since the electric field in which this electron emission is performed depends on the coercive electric field, the drive voltage system can be lowered as the coercive electric field is smaller.
[0120]
Further, in this electron emission method, by controlling the level of the second voltage Va2 applied between the cathode electrode 16 and the anode electrode 20, within a predetermined time tc1, for example, within 10 μsec from the start point of the electron emission period T2. An electric field exceeding the coercive electric field can be applied to the emitter section 14.
[0121]
In this case, the level control of the second voltage Va2 controls only the maximum amplitude (= Va2) if the second voltage Va2 is in the form of a pulse and is a rectangular pulse as shown in FIG. 9A. As shown in FIG. 9B, if the trailing edge is a ramp-like pulse, for example, the maximum amplitude of the second voltage Va2 and the shift time ta (time from the start of the electron emission period T2 until reaching the maximum amplitude) are controlled. To do.
[0122]
In the electron-emitting device 10Aa according to the first specific example, in order to realize continuous electron emission, it is easily realized by adopting a waveform having positive and negative alternating pulses as the waveform of the driving voltage Va. Can do.
[0123]
Next, an electron-emitting device 10Ab according to a second specific example will be described. The electron-emitting device 10Ab according to the second specific example is the same as the configuration of the electron-emitting device 10A according to the first embodiment described above except that the constituent material of the emitter section 14 is an antiferroelectric material. It is.
[0124]
Here, an electron emission method of the electron emitter 10Ab according to the second specific example will be described.
[0125]
First, as shown in FIG. 10, the polarization-electric field characteristics of the antiferroelectric material that is the constituent material of the emitter section 14 are observed only in the induced polarization proportional to the voltage under a low electric field, but exceed a certain electric field. And ferroelectric (electric field induced forced phase transition), and polarization hysteresis appears with respect to the upper and lower sides of the electric field. However, when the electric field is removed again, the original paraelectric material (the state in which the polarization is reset) is restored.
[0126]
When attention is paid to the curves from points p11 to p12 to p13 among the hysteresis curves, most of the antiferroelectric material is polarized in one direction at the point p11 to which the positive electric field is applied. After that, when the electric field strength is reduced, the amount of polarization starts to rapidly decrease from around the point p12, and becomes a paraelectric material at the point p13 where the electric field strength is 0, and the polarization is reset. It has become. Thereafter, when a negative electric field is applied, the emitter section 14 undergoes a phase transition to a ferroelectric material, and polarization inversion begins to occur around the point p14 of the electric field (about −2300 V / mm). Polarization will be performed in the direction.
[0127]
Therefore, in the second specific example, as shown in FIG. 11, first, in the preparation period T1, the first voltage Va1 is applied between the cathode electrode 16 and the anode electrode 20, and the positive electrode is applied to the emitter section 14. An electric field (approximately 3000 V / mm) is applied. At this time, as can be seen from the polarization-electric field characteristics of FIG. 10, the emitter section 14 is polarized in one direction. Note that the first voltage Va1 may be set to the reference voltage (0V) so that no electric field is applied to the emitter section 14 during the preparation period T1. In this case, as can be seen from the polarization-electric field characteristics, the emitter section 14 is in an unpolarized state in advance.
[0128]
Thereafter, in the electron emission period T2, the second voltage Va2 is applied between the cathode electrode 16 and the anode electrode 20, and an electric field (for example, about −3000 V / mm) is applied to the emitter section 14 at high speed. When the portion 14 is changed in polarization, electrons are emitted at a point p16 before reaching the point p15 in FIG.
[0129]
As shown in FIG. 11, the voltage drop is observed at the peak time point P1 of the voltage Vak between the cathode electrode 16 and the anode electrode 20 within a certain time tc2 (in this case, 10 μsec) from the start time of the electron emission period T2. It can be seen that electron emission is performed at the peak time P1. That is, current (collector current Ic) rapidly flows through the collector electrode 24 at the peak time point P 1, which indicates that emitted electrons are captured by the collector electrode 24.
[0130]
By the way, when the antiferroelectric material becomes a ferroelectric material by phase transition, the difference between the electric field from which electrons are emitted (the electric field at the point p16) and the electric field at which the polarization is almost reset (the electric field at the point p17) is small. Therefore, once electrons are emitted and the voltage between the cathode electrode 16 and the anode electrode 20 drops, the polarization of the emitter section 14 is easily reset, and a pseudo reference voltage of 0 V is applied.
[0131]
However, in this electron emission period T2, since the second voltage Va2 is applied between the cathode electrode 16 and the anode electrode 20, the voltage Vak between the cathode electrode 16 and the anode electrode 20 is rapidly required for electron emission. The level is reached and electrons are emitted again.
[0132]
Accordingly, by continuing to apply the second voltage Va2 during the electron emission period T2, the above-described series of operations can be continuously performed, and by controlling the level of the second voltage Va2, the number of consecutive times can be increased. Can also be controlled. In the example of FIG. 10, the case where electron emission was performed 4 times continuously is shown.
[0133]
As described above, in the electron emission method of the electron-emitting device 10Ab according to the second specific example, an electric field is applied to the emitter section 14 at a high speed, and the emitter section 14 is phase-shifted to a ferroelectric material. By changing the polarization, electrons are efficiently emitted, and application to a display or a light source can be facilitated.
[0134]
In addition, the electric field in which electron emission is performed (the electric field at the point p16) is an electric field in which the polarization inversion is almost completed, and these electric fields are almost constant. That is, it becomes a digital electron emission characteristic. In addition, since the electric field in which this electron emission is performed depends on the electric field (forced phase transition electric field) at which the emitter section 14 undergoes phase transition to the ferroelectric material, the lower the forced phase transition electric field, the lower the drive voltage system voltage becomes. It becomes possible.
[0135]
Further, in this electron emission method, the polarization can be almost reset without applying the applied electric field to the positive polarity. Therefore, in the electron emission period T2, electrons can be emitted only by one-sided polarity driving (drive to negative polarity). This leads to simplification of the drive circuit system, which is advantageous in terms of low power consumption, low cost, and downsizing of the structure.
[0136]
In addition, by controlling the level of the second voltage Va2 applied between the cathode electrode 16 and the anode electrode 20 (controlling the maximum amplitude and the shift time ta), it is within a certain time tc2 from the start of the electron emission period T2. For example, within 10 μsec, it is possible to apply an electric field that causes the emitter section 14 to undergo phase transition to the ferroelectric material and polarize the emitter section 14.
[0137]
Next, an electron-emitting device 10Ac according to a third specific example will be described. The electron-emitting device 10Ac according to the third specific example is the same as the configuration of the electron-emitting device 10A according to the first embodiment described above except that the constituent material of the emitter section 14 is an electrostrictive material. .
[0138]
Here, an electron emission method of the electron emitter 10Ac according to the third specific example will be described. First, as shown in FIG. 12, the polarization-electric field characteristics of the electrostrictive material, which is a constituent material of the emitter section 14, are polarized in an amount substantially proportional to the electric field, and in particular, the rate of change of polarization at a low electric field. It is larger than the change in polarization at a high electric field. In any case, it can be seen that the polarization in the emitter section 14 occurs diffusely according to the change in the electric field. When the electric field is removed, the polarization is reset.
[0139]
When attention is paid to the curves from the points p21 to p23 among these characteristic curves, the electrostrictive material is mostly polarized in one direction at the point p21 to which the positive electric field is applied. After that, when the electric field strength is reduced, the amount of polarization in one direction is reduced according to the strength of the positive electric field, and at the point p22 where the electric field strength is 0, it becomes a paraelectric, and the polarization is reset. It has become a state. Thereafter, when a negative electric field is applied, polarization inversion begins to occur, and as the negative electric field strength increases, the amount of polarization in the other direction increases, and most of the polarization is polarized in the other direction at point p23. Will be. That is, the emitter section 14 is polarized by an amount corresponding to the applied electric field.
[0140]
Therefore, in the third specific example, as shown in FIG. 13, first, in the preparation period T1, the first voltage Va1 is applied between the cathode electrode 16 and the anode electrode 20, and the positive electrode with respect to the emitter section 14 is applied. An electric field (approximately 2000 V / mm) is applied. At this time, as can be seen from the polarization-electric field characteristics of FIG. 12, the emitter section 14 is polarized in one direction. Note that the first voltage Va1 may be set to the reference voltage (0V) so that no electric field is applied to the emitter section 14 during the preparation period T1. In this case, as can be seen from the polarization-electric field characteristics, the emitter section 14 is in an unpolarized state in advance.
[0141]
After that, in the electron emission period T2, the second voltage Va2 is applied between the cathode electrode 16 and the anode electrode 20, and an electric field (for example, about −2000 V / mm) is applied to the emitter section 14, thereby causing the emitter section 14 to operate. Is changed in polarization, electrons are emitted at the point p23. As shown in FIG. 13, this is because a voltage drop is observed at the peak time point P1 of the voltage Vak between the cathode electrode 16 and the anode electrode 20 within a certain time tc3 (here, within 10 μsec) from the start time of the electron emission period T2. It can be seen that electron emission is performed at the peak time P1. That is, current (collector current Ic) rapidly flows through the collector electrode 24 at the peak time point P 1, which indicates that emitted electrons are captured by the collector electrode 24.
[0142]
As described above, in the electron-emitting device 10Ac according to the third specific example, the polarization in the emitter section 14 occurs diffusely according to the change in the electric field. Therefore, as the amount of polarization per unit time increases, the amount of electron emission increases. Become more. That is, it becomes an analog electron emission characteristic.
[0143]
Further, the potential difference between the electric field in the electric field from which electrons are emitted (point p23) and the electric field in which the polarization is reset (electric field at point p22) is small. Therefore, once electrons are emitted and the voltage Vak between the cathode electrode 16 and the anode electrode 20 drops, the polarization of the emitter section 14 is easily reset, and a pseudo reference voltage of 0 V is applied.
[0144]
However, in this electron emission period T2, since the second voltage Va2 is applied between the cathode electrode 16 and the anode electrode 20, the voltage Vak between the cathode electrode 16 and the anode electrode 20 rapidly increases and is again polarized. Will be done. At this time, since the polarization changes rapidly, electrons are emitted at a voltage lower than the voltage at the time of the first electron emission.
[0145]
When the second electron emission is performed and the voltage Vak between the cathode electrode 16 and the anode electrode 20 drops, the polarization of the emitter section 14 is easily reset again, and then the second voltage between the cathode electrode 16 and the anode electrode 20 is reset. By the continuous application of the voltage Va2 of 2, the voltage Vak between the cathode electrode 16 and the anode electrode 20 is increased again, and polarization is performed. Also in this case, since the change of polarization proceeds rapidly, the electron emission is performed at the same voltage as the voltage at the second electron emission.
[0146]
That is, after the first electron emission, the voltage Vak between the cathode electrode 16 and the anode electrode 20 slightly vibrates, and the electron emission is sustained by this minute vibration. It is also possible to control the duration of electron emission by controlling the level of the second voltage Va2.
[0147]
As described above, in the electron emission method of the electron emitter 10Ac according to the third specific example, electrons can be efficiently emitted by controlling the amount of polarization in the emitter section 14, so that a display, a light source, etc. Application to can be facilitated.
[0148]
Further, as described above, the greater the amount of polarization per unit time, the lower the strength of the electric field, so that the drive voltage system can be lowered.
[0149]
Further, in this electron emission method, the polarization can be almost reset without applying the applied electric field to the positive polarity. Therefore, in the electron emission period T2, electrons can be emitted only by one-sided polarity driving (drive to negative polarity). This leads to simplification of the drive circuit system, which is advantageous in terms of low power consumption, low cost, and downsizing of the structure.
[0150]
Further, by controlling the level of the second voltage Va2 applied between the cathode electrode 16 and the anode electrode 20 (controlling the maximum amplitude and the shift time ta), a predetermined time tc3 from the start time of the electron emission period T2. Among them, the amount of electron emission can be controlled by controlling the amount of polarization of the emitter section 14 occurring within 10 μsec, for example.
[0151]
Next, an electron-emitting device 10B according to a second embodiment will be described with reference to FIGS. 14 to 23B.
[0152]
As shown in FIG. 14, the electron-emitting device 10B according to the second embodiment has substantially the same configuration as the electron-emitting device 10A according to the first embodiment described above, but the cathode electrode 16 is a plate. It differs in that it is formed on the surface of the emitter portion 14 and the anode electrode 20 is formed on the back surface of the emitter portion 14.
[0153]
Note that the drive voltage Va is applied between the cathode electrode 16 and the anode electrode 20 through a lead electrode 17 extending to the cathode electrode 16 and a lead electrode 21 extending to the anode electrode 20, as shown in FIG.
[0154]
When the electron-emitting device 10B is used as a display pixel, a collector electrode 24 is disposed above the cathode electrode 16, and a phosphor 28 is applied to the collector electrode 24.
[0155]
The thickness h (FIG. 14) of the emitter portion 14 between the cathode electrode 16 and the anode electrode 20 is reversed in polarity by an electric field E expressed by E = Vak / h, where Vak is the voltage between the electrodes 16 and 20. It is preferable to set the thickness h so that is performed. That is, as the thickness h is smaller, polarization inversion or polarization change is possible at a lower voltage, and electrons can be emitted by driving at a lower voltage (for example, less than 100 V). The dielectric breakdown voltage of the emitter section 14 is preferably at least 10 kV / mm or more. Here, the dielectric breakdown voltage of the emitter section 14 is preferably at least 10 kV / mm or more. In this example, when the thickness h of the emitter section 14 is set to 20 μm, for example, even if a drive voltage of −100 V is applied between the cathode electrode 16 and the anode electrode 20, the emitter section 14 does not cause dielectric breakdown.
[0156]
The planar shape of the cathode electrode 16 may be an elliptical shape as shown in FIG. 15, or may be a ring shape like the electron-emitting device 10Ba according to the first modification shown in FIG. Or you may make it comb-tooth shape like electron emission element 10Bb which concerns on the 2nd modification shown in FIG.
[0157]
By making the planar shape of the cathode electrode 16 into a ring shape or a comb-like shape, the triple point of the cathode electrode 16 / emitter portion 14 / vacuum which is also the electric field concentration point A is increased, and the electron emission efficiency can be improved.
[0158]
The thickness tc (see FIG. 14) of the cathode electrode 16 is preferably 20 μm or less, and preferably 5 μm or less. Therefore, the thickness tc of the cathode electrode 16 may be 100 nm or less. In particular, when the thickness tc of the cathode electrode 16 is extremely thin (10 nm or less) as in the electron-emitting device 10Bc according to the third modification shown in FIG. Electrons are emitted from the interface, and the electron emission efficiency can be further improved.
[0159]
On the other hand, the anode electrode 20 is formed by the same material and method as the cathode electrode 16, but is preferably formed by the thick film forming method. The thickness of the anode electrode 20 is also preferably 20 μm or less, and preferably 5 μm or less.
[0160]
Next, the principle of electron emission of the electron emitter 10B will be described with reference to FIGS. 14 and 19 to 23B. Also in the second embodiment, as shown in FIG. 19, as in the first embodiment described above, the period during which the first voltage Va1 is output (preparation period T1) and the second voltage Va2 are output. Is a step (electron emission period T2), and the one step is repeated.
[0161]
First, in the preparation period T1, as shown in FIG. 20, when the first voltage Va1 is applied between the cathode electrode 16 and the anode electrode 20, the emitter section 14 is polarized in one direction. Also in this case, the first voltage Va1 may be a DC voltage as shown in FIG. 19, but one pulse voltage or a pulse voltage may be continuously applied a plurality of times. The preparation period T1 is preferably longer than the electron emission period T2 in order to sufficiently perform the polarization process. For example, the preparation period T1 is preferably 100 μsec or more.
[0162]
After that, in the electron emission period T2, by applying the second voltage Va2 between the cathode electrode 16 and the anode electrode 20, at least a part of the emitter section 14 is polarized or inverted or changed in polarization as shown in FIG. The Here, the portion where the polarization is reversed or changed is not only the portion directly below the cathode electrode 16 but also the portion where the cathode electrode 16 is not directly above and the surface is exposed, in the vicinity of the cathode electrode 16. Then, similarly, polarization inversion or polarization change is performed. That is, in the vicinity of the cathode electrode 16, the portion where the surface of the emitter portion 14 is exposed has the appearance of polarization. Due to this polarization reversal or polarization change, a local concentrated electric field is generated between the cathode electrode 16 and the positive side of the dipole moment in the vicinity thereof, whereby primary electrons are extracted from the cathode electrode 16 and extracted from the cathode electrode 16. The primary electrons thus collided with the emitter section 14 and secondary electrons are emitted from the emitter section 14.
[0163]
When the cathode electrode 16, the emitter section 14, and the vacuum triple point A are provided as in the second embodiment, primary electrons are extracted from the vicinity of the triple point A in the cathode electrode 16, The primary electrons extracted from the triple point A collide with the emitter section 14 and secondary electrons are emitted from the emitter section 14. When the thickness of the cathode electrode 16 is extremely thin (˜10 nm), electrons are emitted from the interface between the cathode electrode 16 and the emitter section 14.
[0164]
Here, the operation by applying the second voltage Va2 will be described in more detail. First, when the second voltage Va2 is applied between the cathode electrode 16 and the anode electrode 20, secondary electrons are emitted from the emitter section 14 as described above. That is, the dipole moment charged in the vicinity of the cathode electrode 16 in the emitter portion 14 whose polarization has been reversed or changed in polarization leads to extracting emitted electrons.
[0165]
That is, a local cathode is formed in the vicinity of the interface with the emitter portion 14 in the cathode electrode 16, and the + pole of the dipole moment charged in the portion in the vicinity of the cathode electrode 16 in the emitter portion 14 is local. Electrons are extracted from the cathode electrode 16 as a typical anode, and some of the extracted electrons are guided to the collector electrode 24 (see FIG. 14) to excite the phosphor 28, and fluorescent to the outside. It will be embodied as body light emission. Among the extracted electrons, some of the electrons collide with the emitter section 14, secondary electrons are emitted from the emitter section 14, and the secondary electrons are guided to the collector electrode 24, thereby causing the phosphor 28 to pass through. Will be excited. Note that the secondary electron emission distribution in the electron-emitting device 10B according to the second embodiment also has the same characteristics as in FIG. Therefore, the majority of secondary electrons have almost energy close to 0. When the secondary electrons are emitted from the surface of the emitter section 14 into the vacuum, they move only according to the surrounding electric field distribution. That is, secondary electrons are accelerated according to the surrounding electric field distribution from a state where the initial velocity is almost 0 (m / sec). Therefore, as shown in FIG. 14, if an electric field Ea is generated between the emitter section 14 and the collector electrode 24, the emission trajectory of the secondary electrons is determined along the electric field Ea. That is, an electron source with high straightness can be realized. Such secondary electrons with a small initial velocity are electrons in the solid that have gained energy by Coulomb collision of the primary electrons and jumped out of the emitter section 14.
[0166]
In addition, primary electron energy E₀The secondary electrons having energy equivalent to are those in which the primary electrons emitted from the cathode electrode 16 are scattered near the surface of the emitter section 14 (reflected electrons). Here, the secondary electrons emitted from the emitter section 14 to the phosphor are secondary electrons having a small initial velocity, that is, electrons in the solid that have jumped out of the emitter section 14 by obtaining energy by Coulomb collision of the primary electrons. And all of Auger electrons and reflected electrons. When the thickness of the cathode electrode 16 is extremely thin (˜10 nm), the primary electrons emitted from the cathode electrode 16 are reflected at the interface between the cathode electrode 16 and the emitter section 14 and travel toward the collector electrode 24.
[0167]
Here, as shown in FIG. 21, the electric field strength E at the electric field concentration point A is shown._AIs the potential difference between the local anode and the local cathode, V (la, lk), and the distance between the local anode and the local cathode, d_AWhen E_A= V (la, lk) / d_AThere is a relationship. In this case, the distance d between the local anode and the local cathode_AIs very small, the electric field strength required for electron emission E_ACan be easily obtained (electric field strength E_A(Indicated by a solid arrow in FIG. 21). This leads to lowering of the voltage Vak.
[0168]
If the electron emission from the cathode electrode 16 proceeds as it is, the constituent atoms of the emitter section 14 which are evaporated and floated by Joule heat are ionized into positive ions and electrons by the emitted electrons, and the electrons generated by the ionization are generated. Further ionizes the constituent atoms and the like of the emitter section 14, so that the number of electrons increases exponentially, and when this proceeds and the electrons and positive ions are neutral, local plasma is formed. It is conceivable that secondary electrons also promote the ionization. It is conceivable that the positive electrode generated by the ionization collides with, for example, the cathode electrode 16 to damage the cathode electrode 16.
[0169]
However, in the electron-emitting device 10B according to the second embodiment, as shown in FIG. 22, the electrons extracted from the cathode electrode 16 become the positive pole of the dipole moment of the emitter section 14 existing as a local anode. As a result, the charging of the surface of the emitter section 14 in the vicinity of the cathode electrode 16 to the negative polarity proceeds. As a result, the electron acceleration factor (local potential difference) is relaxed, the potential leading to secondary electron emission does not exist, and the negative charging on the surface of the emitter portion 14 further proceeds.
[0170]
Therefore, the positive polarity of the local anode at the dipole moment is weakened, and the electric field strength E between the local anode and the local cathode is reduced._A(Electric field strength E_AIs indicated by a dashed arrow in FIG. 22), the electron emission is stopped.
[0171]
That is, as shown in FIG. 23A, when the drive voltage Va applied between the cathode electrode 16 and the anode electrode 20 is set to, for example, + 50V for the first voltage Va1 and -100V for the second voltage Va2, for example, electron emission The voltage change ΔVak between the cathode electrode 16 and the anode electrode 20 at the peak time point P1 at which is performed is within 20V (about 10V in the example of FIG. 23B) and hardly changes. Therefore, there is almost no generation of positive ions, damage to the cathode electrode 16 due to positive ions can be prevented, which is advantageous in extending the life of the electron-emitting device 10B.
[0172]
By the way, electrons emitted from the emitter section 14 collide with the emitter section 14 again, ionization in the vicinity of the surface of the emitter section 14, etc., the emitter section 14 is damaged, crystal defects are induced, and structurally May become brittle.
[0173]
Therefore, it is preferable that the emitter section 14 is made of a dielectric material having a high evaporation temperature in vacuum, for example, BaTiO not containing Pb._ThreeYou may make it comprise by these. Thereby, the constituent atoms of the emitter section 14 are not easily evaporated by Joule heat, and the promotion of ionization by electrons can be prevented. This is effective in protecting the surface of the emitter section 14.
[0174]
Next, an electron-emitting device 10C according to a third embodiment will be described with reference to FIG.
[0175]
The electron-emitting device 10C according to the third embodiment has substantially the same configuration as the electron-emitting device 10A according to the first embodiment described above, as shown in FIG. The anode electrode 20 is formed on the substrate 12, the emitter section 14 is formed on the substrate 12 and covers the anode electrode 20, and the cathode electrode 16 is formed on the emitter section 14. Is different.
[0176]
Also in this case, similarly to the electron-emitting device 10B according to the second embodiment described above, damage to the cathode electrode 16 due to positive ions can be prevented, which is advantageous in extending the life of the electron-emitting device 10C.
[0177]
In the electron-emitting devices 10B and 10C according to the above-described second and third embodiments, the above-described piezoelectric material, antiferroelectric material, and electrostrictive material can be used as the constituent material of the emitter section 14.
[0178]
In the electron-emitting devices 10B and 10C according to the second and third embodiments described above, the dipole moment that appears on the cathode electrode 16 side is only positive or negative. A large local electric field can be obtained. In addition, in the second and third embodiments, only the positive pole of the dipole moment is disposed in the vicinity of the negative polarity cathode electrode 16 at the time of polarization reversal or polarization change of the emitter section 14. Therefore, it is preferable for extracting primary electrons from the cathode electrode 16.
[0179]
Further, in the electron emitters 10B and 10C according to the second and third embodiments described above, one cathode electrode 16 and one anode electrode 20 are formed on one emitter section 14 respectively, thereby emitting one electron. Although an example in which the element 10B (10C) is configured has been shown, a plurality of electron-emitting elements 10 (1), 10 (2), and 10 (3) are provided in one emitter section 14 as shown in FIG. It is also possible to form.
[0180]
That is, in the first configuration example 100A shown in FIG. 25, a plurality of cathode electrodes 16a, 16b, and 16c are independently formed on the surface of one emitter section 14, and a plurality of anode electrodes 20a, 20b are formed on the back surface of the emitter section. 20c are formed to form a plurality of electron-emitting devices 10 (1), 10 (2), and 10 (3). Each of the anode electrodes 20a, 20b, and 20c is formed below the corresponding cathode electrode 16a, 16b, and 16c with the emitter portion 14 interposed therebetween.
[0181]
In the second configuration example 100B shown in FIG. 26, a plurality of cathode electrodes 16a, 16b, and 16c are independently formed on the surface of one emitter section 14, and one anode electrode 20 (a common electrode is formed on the back surface of the emitter section 14). A case where a plurality of electron-emitting devices 10 (1), 10 (2), and 10 (3) are formed by forming an anode electrode) is shown.
[0182]
In the third configuration example 100C shown in FIG. 27, one ultrathin (˜10 nm) cathode electrode 16 (common cathode electrode) is formed on the surface of one emitter section 14, and independent on the back surface of the emitter section 14. 5 shows a case where a plurality of anode electrodes 20a, 20b, and 20c are formed to form a plurality of electron-emitting devices 10 (1), 10 (2), and 10 (3).
[0183]
In the fourth configuration example 100D shown in FIG. 28, a plurality of anode electrodes 20a, 20b, and 20c are independently formed on the substrate 12, and one emitter section 14 is formed so as to cover these anode electrodes 20a, 20b, and 20c. In addition, a plurality of cathode electrodes 16a, 16b, and 16c are independently formed on the emitter section 14 to form a plurality of electron-emitting devices 10 (1), 10 (2), and 10 (3). Indicates. Each cathode electrode 16a, 16b, 16c is formed on the corresponding anode electrode 20a, 20b, 20c, respectively, with the emitter portion 14 interposed therebetween.
[0184]
In the fifth configuration example 100E shown in FIG. 29, one anode electrode 20 is formed on the substrate 12, one emitter section 14 is formed so as to cover the anode electrode 20, and a plurality of emitter sections 14 are formed on the emitter section 14. The cathode electrodes 16a, 16b, and 16c are formed independently to form a plurality of electron-emitting devices 10 (1), 10 (2), and 10 (3).
[0185]
In the sixth configuration example 100F shown in FIG. 30, a plurality of anode electrodes 20a, 20b, and 20c are independently formed on the substrate 12, and one emitter section is formed so as to cover the plurality of anode electrodes 20a, 20b, and 20c. 14 is formed, and further, one ultrathin cathode electrode 16 is formed on the emitter section 14 to form a plurality of electron-emitting devices 10 (1), 10 (2), and 10 (3).
[0186]
In the first to sixth configuration examples 100A to 100F, a plurality of electron-emitting devices 10 (1), 10 (2), and 10 (3) can be configured by one emitter section 14, and will be described later, for example. Thus, it is suitable when each electron-emitting device 10 (1), 10 (2), 10 (3) is configured as a display pixel.
[0187]
In the electron-emitting devices 10A to 10C according to the first to third embodiments described above, when the phosphor 28 is applied to the collector electrode 24 as shown in FIG. Such effects can be achieved.
[0188]
(1) It can be made ultra-thin (panel thickness = several mm) as compared with CRT.
[0189]
(2) Due to spontaneous light emission by the phosphor 28, a wide viewing angle of approximately 180 ° can be obtained as compared with LCD (Liquid Crystal Display) and LED (Light Emitting Diode).
[0190]
(3) Since a surface electron source is used, there is no image distortion as compared with a CRT.
[0191]
(4) High-speed response is possible as compared with LCD, and moving image display without afterimage is possible with a high-speed response on the order of μsec.
[0192]
(5) It is about 100 W in terms of 40 inches, and consumes less power than CRT, PDP (plasma display), LCD and LED.
[0193]
(6) Wide operating temperature range (-40 to + 85 ° C) compared to PDP and LCD. Incidentally, the response speed of the LCD decreases at low temperatures.
[0194]
(7) Since the phosphor can be excited by a large current output, the brightness can be increased as compared with a conventional FED display.
[0195]
(8) Since the drive voltage can be controlled by the polarization reversal characteristics (or polarization change characteristics) and the film thickness of the piezoelectric material, it can be driven at a lower voltage than a conventional FED display.
[0196]
From such various effects, various display applications can be realized as described below.
[0197]
(1) It is most suitable for 30-60 inch display home use (television, home theater) and public use (waiting room, karaoke, etc.) in terms of realizing high brightness and low power consumption.
[0198]
(2) From the aspect that high brightness, large screen, full color, and high definition can be realized, it has a great effect on customer attraction (in this case, visual attention). Ideal for use in exhibitions, message boards for information guides.
[0199]
(3) It is most suitable for in-vehicle displays from the viewpoint that high brightness, a wide viewing angle accompanying phosphor excitation, and a wide operating temperature range associated with vacuum modularization can be realized. The specifications for the in-vehicle display are: 8 inches wide (pixel pitch: 0.14 mm) such as 15: 9, operating temperature of -30 to + 85 ° C., 500 to 600 cd / m in the perspective direction.²is required.
[0200]
In addition, from the various effects described above, various light source applications can be realized as described below.
[0201]
(1) From the standpoint that high luminance and low power consumption can be realized, it is most suitable for a light source for a projector that requires 2000 lumens as a luminance specification.
[0202]
(2) A high-brightness two-dimensional array light source can be easily realized, the operating temperature range is wide, and the luminous efficiency does not change even in an outdoor environment. For example, it is optimal as an alternative to a two-dimensional array LED module such as a traffic light. Note that the LED has a lower allowable current at a temperature of 25 ° C. or higher and low luminance.
[0203]
It should be noted that the electron emission method of the electron-emitting device according to the present invention is not limited to the above-described embodiment, and it goes without saying that various configurations can be adopted without departing from the gist of the present invention.
[0204]
【The invention's effect】
As described above, according to the electron emission method of the electron-emitting device according to the present invention, the electron-emitting device having an emitter portion made of a piezoelectric material can be efficiently made to emit electrons, Application to a display or a light source can be facilitated.
[0205]
In addition, according to the electron emission method of the electron emission device according to the present invention, the electron emission device having the emitter portion made of the antiferroelectric material can be efficiently made to emit electrons, and the display And can be easily applied to a light source or the like.
[0206]
In addition, according to the electron emission method of the electron emission device according to the present invention, the electron emission device having an emitter portion made of an electrostrictive material can efficiently emit electrons, and a display or a light source Etc. can be easily applied.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing an electron-emitting device according to a first embodiment (electron-emitting devices according to first to third specific examples).
FIG. 2 is a plan view showing an electrode portion of the electron-emitting device according to the first embodiment.
FIG. 3 is a waveform diagram showing a drive voltage output from a pulse generation source.
FIG. 4 is an explanatory diagram showing an operation when a first voltage is applied between a cathode electrode and an anode electrode.
FIG. 5A is an explanatory view showing an action (emission of primary electrons) when a second voltage is applied between the cathode electrode and the anode electrode, and FIG. 5B shows the emitted primary electrons; It is explanatory drawing which shows the principle in which a secondary electron is discharge | released based on.
FIG. 6 is a characteristic diagram showing the relationship between the energy of emitted secondary electrons and the amount of emitted secondary electrons.
FIG. 7 is a diagram showing polarization-electric field characteristics of a piezoelectric material.
FIG. 8 shows changes in the drive voltage applied between the cathode electrode and the anode electrode, the collector current flowing in the collector electrode, and the voltage between the cathode electrode and the anode electrode in the electron-emitting device according to the first specific example. It is a waveform diagram.
FIG. 9A is a waveform diagram showing an example of a drive voltage (rectangular pulse), and FIG. 9B is a waveform diagram showing another example of a drive voltage (pulse having a ramp-like falling edge).
FIG. 10 is a diagram showing polarization-electric field characteristics of an antiferroelectric material.
FIG. 11 shows changes in the driving voltage applied between the cathode electrode and the anode electrode, the collector current flowing in the collector electrode, and the voltage between the cathode electrode and the anode electrode in the electron-emitting device according to the second specific example. It is a waveform diagram.
FIG. 12 is a diagram showing polarization-electric field characteristics of an electrostrictive material.
FIG. 13 shows changes in the driving voltage applied between the cathode electrode and the anode electrode, the collector current flowing in the collector electrode, and the voltage between the cathode electrode and the anode electrode in the electron-emitting device according to the third specific example. It is a waveform diagram.
FIG. 14 is a configuration diagram showing an electron-emitting device according to a second embodiment.
FIG. 15 is a plan view showing an electrode portion of an electron-emitting device according to a second embodiment.
FIG. 16 is a plan view showing electrode portions in a first modification of the electron-emitting device according to the second embodiment.
FIG. 17 is a plan view showing an electrode portion in a second modification of the electron-emitting device according to the second embodiment.
FIG. 18 is a configuration diagram showing a third modification of the electron-emitting device according to the second embodiment.
FIG. 19 is a waveform diagram showing a drive voltage output from a pulse generation source.
FIG. 20 is an explanatory diagram showing an operation when a first voltage is applied between a cathode electrode and an anode electrode.
FIG. 21 is an explanatory diagram showing an electron emission action when a second voltage is applied between the cathode electrode and the anode electrode.
FIG. 22 is an explanatory diagram showing the action of self-stopping of electron emission accompanying negative charging on the surface of the emitter section.
FIG. 23A is a waveform diagram showing an example of a drive voltage, and FIG. 23B is a waveform diagram showing a change in voltage between the anode electrode and the cathode electrode in the electron-emitting device according to the second embodiment. is there.
FIG. 24 is a configuration diagram showing an electron-emitting device according to a third embodiment.
FIG. 25 is an explanatory diagram showing a first configuration example in which a plurality of electron-emitting devices are combined.
FIG. 26 is an explanatory diagram showing a second configuration example in which a plurality of electron-emitting devices are combined.
FIG. 27 is an explanatory diagram showing a third configuration example in which a plurality of electron-emitting devices are combined.
FIG. 28 is an explanatory diagram showing a fourth configuration example in which a plurality of electron-emitting devices are combined.
FIG. 29 is an explanatory diagram showing a fifth configuration example in which a plurality of electron-emitting devices are combined.
FIG. 30 is an explanatory diagram showing a sixth configuration example in which a plurality of electron-emitting devices are combined.
[Explanation of symbols]
10A, 10Aa to 10Ac, 10B, 10Ba to 10Bc, 10C...
12 ... Substrate 14 ... Emitter
16 ... Cathode electrode 18 ... Slit
20 ... Anode electrode 22 ... Pulse generation source
24 ... Collector electrode 28 ... Phosphor

Claims (13)

An emitter composed of an electrostrictive material;
Have a first electrode and a second electrode formed in contact with the emitter,
An electron emission method of the first and the electron emission is allowed Ru electron-emitting device by via the second electrode by applying an electric field to the emitter to control the amount of polarization in the emitter section,
By applying the electric field between the first electrode and the second electrode, at least a part of the emitter section undergoes polarization inversion or polarization change, and by this polarization inversion or polarization change, By arranging the positive electrode side of the dipole moment in the periphery, primary electrons are extracted from the first electrode,
An electron emission method for an electron-emitting device, wherein primary electrons extracted from the first electrode collide with the emitter portion, and secondary electrons are emitted from the emitter portion. In the electron emission method of the electron-emitting device according to claim 1,
In the first period, a first voltage whose potential of the first electrode is higher than that of the second electrode is applied between the first electrode and the second electrode, and the emitter section is Pre-polarized in one direction,
In the second period, a second voltage whose potential of the first electrode is lower than the potential of the second electrode is applied between the first electrode and the second electrode, and the emitter section is An electron emission method for an electron-emitting device, wherein electrons are emitted by changing polarization. In the electron emission method of the electron-emitting device according to claim 1 ,
The first period, the first voltage you applied between said first electrode and the second electrode as 0V, aft in the previously non-polarized state said emitter portion,
In the second period, a second voltage whose potential of the first electrode is lower than the potential of the second electrode is applied between the first electrode and the second electrode, and the emitter section is An electron emission method for an electron-emitting device, wherein electrons are emitted by changing polarization . In the electron emission method of the electron-emitting device according to claim 2 or 3,
By controlling the level of the second voltage, the amount of polarization of the emitter generated within a certain time from the start of the second period is controlled to control the amount of electron emission. Device electron emission method. In the electron emission method of the electron-emitting device according to any one of claims 2 to 4,
After the electron emission, the second voltage applied at the start of the second period so that the electron emission continues due to the slight oscillation of the voltage between the first electrode and the second electrode. An electron emission method for an electron-emitting device, characterized by controlling the level of the electron emission. In the electron emission method of the electron-emitting device according to any one of claims 1 to 5,
The first electrode is formed in contact with the emitter portion,
The electron emission method of an electron-emitting device, wherein the second electrode is formed in contact with the emitter portion and forms a slit together with the first electrode. In the electron emission method of the electron-emitting device according to claim 6,
When the slit width is d and the voltage between the first electrode and the second electrode is Vak, the polarization is inverted by the electric field E applied to the emitter and expressed by E = Vak / d. Alternatively, an electron emission method for an electron-emitting device, wherein polarization change is performed. In the electron emission method of the electron-emitting device according to any one of claims 1 to 5,
The first electrode is formed on a first surface of the emitter;
The electron emission method for an electron-emitting device, wherein the second electrode is formed on a second surface of the emitter section. The electron emission method for an electron-emitting device according to claim 8,
When the thickness of the emitter section sandwiched between the first electrode and the second electrode is h and the voltage between the first electrode and the second electrode is Vak, the voltage is applied to the emitter section. An electron emission method for an electron-emitting device, wherein polarization inversion or polarization change is performed by an electric field E represented by E = Vak / h. In the electron emission method of the electron-emitting device according to claim 7 or 9,
The electron emission method for an electron-emitting device, wherein the voltage Vak is less than a breakdown voltage of the emitter section. In the electron emission method of the electron-emitting device according to any one of claims 1 to 10,
By applying the electric field between the first electrode and the second electrode, at least a part of the emitter section undergoes polarization inversion or polarization change, and the potential is lower than that of the second electrode. An electron emission method for an electron-emitting device, wherein electrons are emitted from the vicinity of an electrode. In the electron emission method of the electron-emitting device according to any one of claims 1 to 11 ,
The electron-emitting device has a triple point of the first electrode, the emitter, and a vacuum atmosphere,
Primary electrons are extracted from the portion near the triple point of the first electrode,
An electron emission method for an electron-emitting device, wherein the extracted primary electrons collide with the emitter portion and secondary electrons are emitted from the emitter portion. An emitter composed of an electrostrictive material;
A first electrode and a second electrode formed in contact with the emitter portion;
An electron emission method for an electron-emitting device that emits electrons by applying an electric field to the emitter through the first and second electrodes to control the amount of polarization in the emitter,
In the first period, a first voltage whose potential of the first electrode is higher than that of the second electrode is applied between the first electrode and the second electrode, and the emitter section is Pre-polarized in one direction,
In the second period, a second voltage whose potential of the first electrode is lower than the potential of the second electrode is applied between the first electrode and the second electrode, and the emitter section is Electrons are emitted by changing the polarization,
After the electron emission, the second voltage applied at the start of the second period so that the electron emission continues due to the slight oscillation of the voltage between the first electrode and the second electrode. An electron emission method for an electron-emitting device, wherein the level of the electron emission device is controlled.

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