JP2012195112A - Field emission light-emitting device, manufacturing method of field emission light-emitting device, and light-emitting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a field emission light-emitting device in which the loss of radiation light emitted from a phosphor can be reduced with a simple structure.SOLUTION: A field emission light-emitting device 10 comprises an anode substrate 1 having a substrate surface on which an anode electrode 2 is arranged, and a cathode substrate 6 having a substrate surface on which a cathode electrode 3 is arranged. The anode substrate 1 and the cathode substrate 6 are arranged so that the substrate surfaces face each other, and the anode substrate 1 further includes a plurality of phosphor layers 4. The plurality of phosphor layers 4 are arranged at a distance from each other at least one of between the anode substrate 1 and the anode electrode 2 and on the anode electrode 2. The cathode substrate 6 further includes an emitter 5 arranged on the cathode electrode 3. The cathode electrode 3 has light reflectivity and the emitter 5 has optical transparency.

Description

  The present invention relates to a field emission light-emitting device, a method for manufacturing a field emission light-emitting device, and a light-emitting device.

  As a next-generation illumination that can replace incandescent bulbs, fluorescent lamps, etc., electron beam excitation illumination has attracted attention and has been actively developed. In the electron beam excitation type illumination (field emission light emitting device), electrons are emitted from an electron emission source in a vacuum, and phosphors are excited by the electrons, thereby extracting light. As the material of the electron emission source, for example, a carbon nanotube (CNT) or the like having a high aspect ratio and high electrical conductivity and mechanically strong is used (see, for example, Patent Documents 1 and 2).

  A field emission light-emitting device generally has a structure in which an anode provided with a phosphor and a cathode provided with an electron emission source are arranged facing each other. The light generated by the excitation of the phosphor is transmitted through the glass substrate of the anode and emitted to the outside. However, the electron beam excitation illumination of this general structure has a problem that the light emitted from the phosphor is radiated to the cathode side, resulting in a loss of light emission efficiency. .

  In order to solve this problem, various field emission light emitting devices have been proposed (for example, Patent Documents 3 to 5).

  In Patent Document 3, a gate electrode for controlling an electric field applied to the electron emission source is formed between the cathode electron emission source and the anode phosphor, and a reflection surface is provided on the phosphor side of the gate electrode. A field emission light emitting device is disclosed.

  Patent Document 4 discloses a field emission light-emitting device in which a light reflection film is formed on a portion where an electron-emitting device is not formed on a surface where an electron emission source of a cathode is formed.

  Patent Document 5 discloses a field emission light emitting device in which an emitter having a film thickness of 10 μm or less and a light transmittance of 50% or more and a reflecting mirror on a surface opposite to a side where a cathode emitter is provided are provided. Is disclosed. According to this apparatus, out of the light generated from the phosphor, the light transmitted through the emitter is reflected by the reflecting mirror and taken out to the anode side.

Japanese Patent No. 3595233 Japanese Patent No. 4354432 Japanese Patent No. 4347343 JP 2006-278319 A JP 2006-278226 A

  However, the field emission light-emitting device described in Patent Document 3 has a complicated structure and manufacturing process because the gate electrode is provided between the cathode and the anode, and the reflective surface is provided on the phosphor side of the gate electrode. Cost. In addition, of the light emitted from the phosphor, the light that reaches the electron emission source is absorbed by the electron emission source, and thus it is difficult to reduce the loss of the emitted light.

  In addition, the field emission light emitting device described in Patent Document 4 has a simple structure because a light reflection film is only formed on a portion where no electron-emitting device is formed. However, of the light emitted from the phosphor, the light that reaches the electron-emitting device is absorbed by the electron-emitting device, so that it is difficult to reduce the loss of emitted light.

  The field emission light-emitting device described in Patent Document 5 is provided with a reflecting mirror on the side opposite to the side where the cathode emitter is provided, so that the structure and the manufacturing process are only complicated. Therefore, the thickness of the entire apparatus becomes large, which is not practical.

  Therefore, an object of the present invention is to provide a field emission light-emitting device, a method for manufacturing the field emission light-emitting device, and a light-emitting device that have a simple structure and can reduce loss of emitted light emitted from a phosphor.

In order to achieve the above object, the field emission light emitting device of the present invention comprises:
An anode substrate having an anode electrode disposed on the substrate surface;
A cathode substrate having a cathode electrode disposed on the substrate surface;
The anode substrate and the cathode substrate are arranged such that the substrate surfaces face each other,
The anode substrate further includes a plurality of phosphor layers,
The plurality of phosphor layers are disposed between the anode substrate and the anode electrode and at least one on the anode electrode, spaced apart from each other,
The cathode substrate further includes an emitter,
The emitter is disposed on the cathode electrode;
The cathode electrode has light reflectivity;
The emitter is light transmissive.

Further, according to the present invention, a method for manufacturing the field emission light-emitting device of the present invention includes
An anode substrate providing step of providing an anode substrate having an anode electrode formed on the substrate surface;
A cathode substrate providing step of providing a cathode substrate in which a cathode electrode having light reflectivity is formed on the substrate surface;
A phosphor layer forming step of forming a plurality of phosphor layers at intervals between at least one of the anode substrate and the anode electrode and on the anode electrode;
Forming an emitter having optical transparency on the cathode electrode; and
A substrate disposing step of disposing the anode substrate and the cathode substrate so that the substrate surfaces face each other.

  The light emitting device of the present invention includes the field emission light emitting device of the present invention.

  According to the present invention, it is possible to provide a field emission light-emitting device, a method for manufacturing a field emission light-emitting device, and a light-emitting device that can reduce the loss of radiation emitted from a phosphor with a simple structure.

FIG. 1 is a cross-sectional view schematically showing a part of the configuration of an example (Embodiment 1) of a field emission light-emitting device of the present invention. FIG. 2 is a plan view schematically showing each constituent member in the first embodiment. FIG. 3 is a graph showing the relationship between the number of peelings and the thickness of the emitter in the example of the present invention. FIG. 4 is a photograph showing an emitter after peeling in an example of the present invention. FIG. 5 is a graph showing the relationship between the thickness of the emitter and the light emission characteristics in the example of the present invention. FIG. 6 is a photograph showing the light emission state of the phosphor layer in the example of the present invention. FIG. 7 is a cross-sectional view schematically showing a part of the configuration of another example in the first embodiment.

  In the present invention, the “to the substrate surface” is not limited to a state in which it is in direct contact with the substrate surface unless otherwise specified, and there may be other components and the like that are not in direct contact with each other. Including. In the present invention, the “substrate surface” of the anode substrate is a surface of the anode substrate facing the cathode substrate, and the “substrate surface” of the cathode substrate is the surface of the cathode substrate. It is a surface on the side facing the anode substrate.

  In the present invention, the term “on” is not limited to the state of being in direct contact with the upper surface unless otherwise specified, and includes a state in which other components are present and not in direct contact with each other. Further, in the present invention, the “on the anode electrode” is a side of the anode electrode facing the cathode substrate, and the “on the cathode electrode” is a side of the cathode electrode facing the anode substrate. Above.

  In the present invention, the “size” of the phosphor layer and the emitter means, for example, a planar area of the phosphor layer and the emitter, or a side length in the planar shape. The length of the side is, for example, the length of one side when the planar shape is a square, the length of the long side or the short side when it is a rectangle other than a square, and the diameter when it is a circle. Or the length of a radius, in the case of an ellipse, the length of a major axis or a minor axis.

  In the present invention, the cathode substrate, the cathode electrode, and the emitter may be collectively referred to as “cathode”, and the anode substrate, the anode electrode, and the phosphor layer may be collectively referred to as “anode”.

  Next, embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited by the following description.

[Embodiment 1]
The field emission light-emitting device of this embodiment is an example of a planar field emission lamp. 1 and 2 show the configuration of the field emission light-emitting device of this embodiment. FIG. 1 is a cross-sectional view schematically showing a part of the field emission light-emitting device of the present embodiment. FIG. 2 is a plan view schematically showing each component of the field emission light-emitting device of the present embodiment. 1 and 2, the same parts are denoted by the same reference numerals.

(1) Overall Configuration As shown in FIGS. 1 and 2, the field emission light-emitting device 10 of this embodiment includes an anode substrate 1 and a cathode substrate 6. An anode electrode 2 is formed on the substrate surface of the anode substrate 1. A cathode electrode 3 is formed on the substrate surface of the cathode substrate 6. The anode substrate 1 and the cathode substrate 6 are disposed so that the substrate surfaces face each other. The anode substrate 1 further has a plurality of phosphor layers 4, and a dot pattern is formed on the anode electrode 2 by the plurality of phosphor layers 4. The cathode substrate 6 further includes a plurality of emitters 5, and a dot pattern is formed on the cathode electrode 3 by the plurality of emitters 5. In the field emission light emitting device 10 of the present embodiment, each dot of the phosphor layer 4 is formed so as to correspond to each dot of the emitter 5 on a one-to-one basis, and further, in a direction perpendicular to the substrate surface of the anode substrate 1. When viewed from (in the vertical direction in FIG. 1), each dot of the emitter 5 is formed inside each dot of the phosphor layer 4, and each dot of the phosphor layer 4 is larger than each dot of the emitter 5. Is set. In the field emission light emitting device 10 of the present embodiment, a structure for vacuum sealing is provided inside the device in order to keep, for example, a vacuum between the anode substrate 1 and the cathode substrate 6 during operation (light emission). It has been. However, the present invention is not limited by the structure. In FIGS. 1 and 2, the structure is not shown for convenience of explanation (hereinafter the same applies to FIG. 7).

(2) Cathode (2-1) Cathode Substrate The cathode substrate 6 is not particularly limited, and for example, an electrically insulating substrate such as a glass substrate, a quartz substrate, an undoped silicon substrate, or the like can be used.

(2-2) Cathode electrode The cathode electrode 3 is an electrode having light reflectivity. Examples of the material for forming such an electrode include a conductive material such as a metal having light reflectivity. The metal may be, for example, a single metal or an alloy composed of two or more kinds of the metals. Examples of the metal include Au, Ag, Al, Cu, Fe, Ni, Co, Pd, Pt, Mo, and W. The light reflectance of the cathode electrode 3 is preferably as high as possible. For example, it is 50% or more, preferably 60% or more, more preferably 80% or more, and ideally 100%. The shape of the cathode electrode 3 is not particularly limited as long as it has light reflectivity, and examples thereof include a layer shape (film shape), a stripe shape, and a mesh shape. The layered (film-like) cathode electrode 3 can be referred to as a cathode conductive layer (cathode conductive film). For the formation of the cathode electrode 3, a conventionally known method can be used. For example, when the cathode electrode 3 is a conductive film, it can be selected from, for example, screen printing, vapor deposition, sputtering, etc. according to the selected forming material. .

(2-3) Emitter The emitter 5 has optical transparency. The shape of the emitter 5 is not particularly limited as long as it has optical transparency. For example, the emitter 5 is preferably layered. The thickness of the emitter 5 is preferably as thin as possible from the viewpoint of light transmittance. The thickness is, for example, in the range of 0.1 to 1.5 μm. By setting the thickness to 0.1 μm or more, it is possible to prevent deterioration of light emission characteristics. Here, “emission characteristic” means, for example, the relationship (current density-electric field curve) between the electric field (E) applied between the cathode electrode and the anode electrode and the current density (J). "" Means, for example, that the current density per applied electric field decreases in the above relationship. In addition, by setting the thickness to 1.5 μm or less, for example, it is possible to ensure transparency, and it is easy to control the thickness. The upper limit of the thickness is more preferably 1.5 μm or less, and still more preferably 1.1, 1.04, 1.0, 0.9, 0.8, 0.7, 0.4, 0.3. Or 0.2 μm or less. The lower limit of the thickness is more preferably 0.19 μm or more.

  The light transmittance (total light transmittance) of the emitter 5 is preferably as high as possible. For example, it is 50% or more, preferably 60% or more, more preferably 80% or more, and ideally 100%. is there. The light transmittance of the emitter 5 is, for example, in the range of 50 to 60%.

  The emitter 5 contains an electron emission material. The electron-emitting material is not particularly limited, and for example, it is preferable to use a material having electric conductivity that easily causes electric field concentration due to a high aspect ratio, and more preferably a carbon nanomaterial. The carbon nanomaterial is not particularly limited, and examples thereof include carbon nanotubes (CNT), carbon nanohorns, carbon nanocoils, graphene sheets, carbon fibers, carbon sticks, and composites thereof. One type of the carbon nanomaterial may be used alone, or a mixture of two or more types may be used. Among these, CNT is particularly preferable because of its high aspect ratio and high current density resistance. Carbon nanotubes are carbon tubular structures having a diameter of, for example, about 0.4 nanometers to several tens of nanometers, and have advantages such as a high aspect ratio and a high current resistance density. Examples of the electron emission material include metal nanowires and metal nanotubes in addition to the carbon nanomaterial. The material for forming the metal nanowire is not particularly limited, and examples thereof include Ni, Co, Fe, and Au. The material for forming the metal nanotube is not particularly limited, and examples thereof include Au, Ag, Pt, Rh, and Ir.

  A method of manufacturing the light-transmitting emitter 5 will be described by taking as an example the case where carbon nanotubes (CNT) are used as the electron emission material. However, the present invention is not limited to this example.

  First, a CNT-containing paste is prepared. That is, first, the CNT is added to a solvent, and this is subjected to, for example, ultrasonic treatment to prepare a dispersion. Furthermore, a glass frit, a binder, etc. are added to this dispersion liquid, for example, it ultrasonically processes and a dispersion liquid is prepared. A CNT-containing paste is prepared by mechanically kneading the dispersion with, for example, a three-roll mill. Next, a coating film of the paste is formed on the cathode electrode formed on the surface of the cathode substrate. The coating film can be formed by, for example, a spray method, an ink jet method, screen printing, hand coating printing, precipitation method, or the like. The thickness in particular of the said coating film is not restrict | limited, For example, it is the range of 1-100 micrometers. And the said coating film is baked and the emitter containing CNT is formed. The firing conditions of the coating film are not particularly limited, and the atmospheric conditions are, for example, vacuum, inert atmosphere, air (air), etc., and the firing temperature is, for example, in the range of 300 to 600 ° C.

  The solvent is not particularly limited, and examples thereof include organic solvents. The organic solvent is preferably a low vapor pressure solvent, for example. Examples of the low vapor pressure solvent include butyl cellosolve acetate, butyl carbitol, butyl carbitol acetate, α-terpineol, and γ-butyrolactone. Moreover, the said organic solvent may use a low boiling-point solvent from a viewpoint of a drying rate, for example. Examples of the low boiling point solvent include ethyl acetate, methyl ethyl ketone, toluene, benzyl alcohol and the like. The said solvent may be used individually by 1 type, and may use 2 or more types together.

The glass frit is, for example, SnO—P ₂ O ₅ glass, SnO—B ₂ O ₃ glass, SnO—B ₂ O ₃ —P ₂ O ₅ glass, Bi ₂ O ₃ —B ₂ O ₃ glass. Etc. can be used. In particular, SnO—P ₂ O ₅ glass is preferable because it has an effect of suppressing combustion of a carbon material such as a carbon nanotube. The combustion temperature of the electron emission material is approximately 500 ° C. or higher, but from the viewpoint of preventing thermal degradation of the electron emission material, the lower the firing temperature, the better. Therefore, the firing temperature of the CNT-containing paste is preferably 500 ° C. or less. For this reason, it is preferable that the glass frit (glass powder) has a softening point of 500 ° C. or less.

  The binder is not particularly limited, and for example, a general organic binder resin can be used. Examples of the organic binder resin include celluloses such as ethyl cellulose, nitrocellulose, cellulose acetate, and hydroxymethyl cellulose; acrylic acid esters, methacrylic acid esters, cyanoacrylic acid esters, or copolymers of these acrylic monomers. Acrylic resin type; vinyl acetate type; polyvinyl alcohol type; polyvinyl acetal type; polyester type resin.

  The emitter formed by the firing can be surface-treated to adjust the light transmittance. Examples of the surface treatment include a treatment (peeling treatment) of raising the emitter once or a plurality of times. By controlling the thickness of the emitter by this process, for example, the light transmittance of the emitter can be adjusted. The number of peeling treatments is not particularly limited, and is, for example, in the range of 1 to 10 times. Examples of the peeling treatment include a tape peeling method, a laser method, a plasma method, and a sand blast method. Among these, the tape peeling method is particularly preferable because the operation is simple. The tape used in the tape peeling method is not particularly limited, and examples thereof include kapton tape and dicing tape.

  Moreover, for example, the light transmittance of the emitter can be adjusted by adjusting the content of the CNT in the CNT-containing paste. The content of the CNT is, for example, in the range of 1 to 30 wt%, preferably in the range of 1 to 10 wt%, with respect to the total amount of the paste.

  As described above, the emitter 5 forms a dot pattern on the cathode electrode 3. The size of each dot is not particularly limited, and the side length of each dot is, for example, in the range of 0.1 to 100 mm, preferably in the range of 1 to 10 mm, or 0.1 to 1 mm. It is a range. The interval between the dots is not particularly limited, and is, for example, in the range of 0.01 to 10 mm, preferably in the range of 1 to 10 mm, or in the range of 0.1 to 1 mm. The planar shape of the dot is not particularly limited, and examples thereof include a square, a rectangle other than a square, a circle, and an ellipse. The size, interval, planar shape, etc. of the dots are preferably set in correspondence with the size, interval, planar shape, etc. of each dot of the phosphor layer 4 described later.

(3) Anode (3-1) Anode Substrate The anode substrate 1 is not particularly limited, and for example, a transparent substrate such as a glass substrate or a quartz substrate is preferably used.

(3-2) Anode Electrode The anode electrode 2 is not particularly limited, and is preferably an electrode having optical transparency, for example. Examples of the material for forming such an electrode include ITO, ZnO, SnO ₂ , carbon nanotube, carbon nanohorn, graphene sheet, and the like. The anode electrode 2 can be formed on the substrate surface of the anode substrate 1 by a conventionally known method using the forming material, for example.

(3-3) Phosphor layer The phosphor layer 4 is, for example, an electron beam that is excited and emits fluorescence when irradiated with an electron beam, similar to that used in CRT (Cathode Ray Tube). It is a layer containing an excitation phosphor. The electron beam-excited phosphor is not particularly limited, and a conventionally known one can be used. For example, a sulfide phosphor, an oxide phosphor, a nitride phosphor or the like can be used.

  The production method of the phosphor layer 4 is not particularly limited. The phosphor layer 4 can be produced, for example, by preparing a paste containing the electron beam excited phosphor, forming a coating film of the paste on the anode electrode 2, and firing the coating film. The coating film can be formed by, for example, a spray method, an ink jet method, screen printing, hand coating printing, precipitation method, or the like. The thickness in particular of the said coating film is not restrict | limited, For example, it is the range of 0.1-100 micrometers. The firing conditions of the coating film are not particularly limited, and the atmospheric conditions are, for example, air (air), nitrogen atmosphere, vacuum, etc., the firing temperature is, for example, in the range of 300 to 600 ° C., and the firing time is 30. A range of minutes to 2 hours is suitable.

  As described above, the phosphor layer 4 has a dot pattern formed on the anode electrode 2. The size of each dot is not particularly limited, and the side length of each dot is, for example, in the range of 0.01 to 100 mm, preferably in the range of 1 to 10 mm, or 0.1 to 1 mm. It is a range. The interval between the dots is not particularly limited, and is, for example, in the range of 0.01 to 10 mm, preferably in the range of 1 to 10 mm, or in the range of 0.1 to 1 mm. The planar shape of the dot is not particularly limited, and examples thereof include a square, a rectangle other than a square, a circle, and an ellipse. The size, interval, planar shape, etc. of the dots are preferably set in correspondence with the size, interval, planar shape, etc. of the dots of the emitter 5, as in the field emission light emitting device 10 of this embodiment. It is more preferable that the dot size of the phosphor layer 4 is set to be larger than the dot size of the emitter 5 in that the electrons from the emitter 5 can be used efficiently. Details will be described later.

(4) Manufacturing method of field emission light-emitting device The field emission light-emitting device 10 of this embodiment can be manufactured as follows, for example. That is, first, as described above, the anode electrode 2 is formed on the substrate surface of the anode substrate 1 and the phosphor layer 4 is formed on the anode electrode 2 to prepare the anode. On the other hand, the cathode electrode 3 is formed on the substrate surface of the cathode substrate 6 and the emitter 5 is formed on the cathode electrode 3 to prepare the cathode. The anode and the cathode can be manufactured by arranging the anode substrate 1 and the cathode substrate 6 so that the substrate surfaces face each other. As described above, in the field emission light emitting device 10 of this embodiment, since the cathode electrode 3 has light reflectivity, for example, like the field emission light emission device of Patent Document 3 or 5, a separate reflecting surface or reflecting mirror is used. The field emission light-emitting device can be manufactured easily and at low cost. In addition, the manufacturing method of this invention is not limited to this example.

(5) Operation of field emission light emitting device (light emission)
The operation (light emission) of the field emission light-emitting device 10 of the present embodiment will be described with reference to FIG.

In the field emission light-emitting device 10 of the present embodiment, for example, a vacuum is maintained between the cathode substrate 6 and the anode substrate 1 during light emission. The vacuum is preferably a vacuum degree of 1 × 10 ⁻³ Pa or less, and more preferably a vacuum degree of 1 × 10 ⁻⁵ Pa or less. The lower limit value of the degree of vacuum is not particularly limited, and is, for example, a value of 0 Pa or more or exceeding 0 Pa.

When the voltage is applied between the two electrodes by a voltage source (not shown in FIG. 1) connected to the cathode electrode 3 and the anode electrode 2 in the vacuum state, the electrons contained in the emitter 5 An electric field is applied to the emitting material, and electrons (e ⁻ ) are emitted. The electrons (e ⁻ ) are accelerated by an electric field applied between the electrodes, and excite the electron beam excited phosphor contained in the phosphor layer 4. Thereby, light is emitted to the anode substrate 1 side of the phosphor layer 4, that is, to the outside of the device, and to the cathode substrate 6 (emitter 5) side of the phosphor layer 4, that is, to the inside of the device. The light emitted to the emitter 5 side is transmitted through the emitter 5 and reflected by the cathode electrode 3, and is emitted to the anode substrate 1 side. The light radiated to the emitter 5 side is reflected by the cathode electrode 3 and radiated to the anode substrate 1 side in a portion where the emitter 5 of the cathode electrode 3 does not exist. Here, in the field emission light emitting device 10 of the present embodiment, since the phosphor layer 4 forms a dot pattern, the anode electrode 2 has a portion where the phosphor layer 4 is not formed. For this reason, the light reflected by the cathode electrode 3 passes through the portion on the anode electrode 2 where the phosphor layer 4 is not formed and the anode substrate 1 and is emitted to the outside of the apparatus. As described above, according to the field emission light emitting device 10 of the present embodiment, the light emission efficiency can be improved by effectively using the emitted light emitted from the phosphor. Further, since the field emission light emitting device 10 of the present embodiment uses the cathode electrode 3 having light reflectivity to reflect the light emitted to the emitter 5 side, the light emitted to the emitter side is used. There is no need to separately provide a reflecting structure, and the structure is simple.

  As shown in FIG. 1, the electrons from the emitter 5 are emitted so as to spread. Here, in the field emission light emitting device 10 of this embodiment, as described above, the size of each dot of the phosphor layer 4 is formed larger than the size of each dot of the emitter 5. For this reason, the electrons spread and emitted from each emitter 5 are effectively used for exciting the phosphor without being lost outside the apparatus. Thereby, for example, the luminous efficiency is further improved. In Patent Documents 3 to 5, since it is not considered that electrons from the electron emission material are accelerated while spreading, an apparatus having a configuration in which the size of the light emitting layer is larger than the size of the emitter is not disclosed. . Therefore, such an effect can be said to be an advantageous effect that is difficult to predict from the prior art.

  Further, in the field emission light emitting device 10 of this embodiment, as described above, since the cathode electrode 3 has light reflectivity, it is not necessary to separately provide a light reflection layer. For this reason, for example, the field emission light-emitting device described in Patent Document 5 (Japanese Patent Laid-Open No. 2006-278226), in which a reflecting mirror is provided on a surface opposite to the side on which the emitter of the cathode substrate is provided. The device can be made thinner than the above.

(6) Other Embodiments In the field emission light emitting device 10 of the present embodiment, as described above, the phosphor layer 4 forms a dot pattern. However, the present invention is not limited to this, and each of the fluorescent layers The body layers should just be arrange | positioned at intervals. In addition to the dot pattern, for example, the arrangement may be a stripe or a lattice. Further, in the field emission light emitting device 10 of the present embodiment, the phosphor layer 4 is formed on the anode electrode 2 as described above, but the present invention is not limited to this. The phosphor layer may be disposed, for example, between the anode electrode and the anode substrate. In other words, for example, when an anode electrode having a thickness that allows an electron beam to pass therethrough is formed on the cathode substrate side surface of the phosphor layer (sometimes referred to as a metal back) and used as the anode electrode, The anode electrode is not necessarily required on the anode substrate side of the phosphor layer. The phosphor layer may be disposed on both the cathode substrate side surface and the anode substrate side surface of the anode electrode.

  In the field emission light emitting device 10 of the present embodiment, as described above, the emitter 5 forms a dot pattern, and the dots are arranged corresponding to the dot pattern of the phosphor layer 4. The invention is not limited to this. The arrangement mode of the emitter is preferably set according to the arrangement mode of the phosphor layer. Further, the emitter may be an emitter 25 formed on the entire surface of the cathode electrode 3 as in the field emission light emitting device 20 shown in FIG. Even in such a form, the effect of the present invention can be obtained that the loss of the emitted light emitted from the phosphor can be reduced with a simple structure.

  In the field emission light emitting device 10 of the present embodiment, the cathode electrode 3 is formed so as to cover almost the entire surface of the cathode substrate 6. For example, the cathode electrode is a portion where the emitter is formed. In the case where the cathode electrode is formed only on the substrate surface, a light reflecting layer having light reflectivity may be disposed on the substrate surface of the cathode substrate at a position where the cathode electrode is not disposed. The material for forming such a light reflection layer is not particularly limited, and examples thereof include a metal having light reflectivity and a white scatterer. Examples of the metal having light reflectivity include the material for forming the cathode electrode described above. A conventionally well-known thing can be used for the said white scatterer, for example.

(7) Applications As described above, the field emission light-emitting device of the present invention has a simple structure and can reduce the loss of radiated light emitted from the phosphor. As a result, the light emission efficiency can be improved. Therefore, the field emission light-emitting device of the present invention can be used for light-emitting devices, electron-emitting devices, and the like. Examples of the optical device include applications such as illumination, display, and backlight. Examples of the electron-emitting device include an emitter used in an electron microscope. However, its use is not limited and can be applied to a wide range of fields.

  Next, examples of the present invention will be shown, and the present invention will be described in detail. In addition, this invention is not limited and restrict | limited at all by the following Example.

[Example 1]
(1) Production of field emission light emitting device (1-1. Production of cathode)
A multiwall carbon nanotube (CNT) was used as an electron emission material to prepare a CNT-containing paste. First, 100 mg of multi-walled CNTs was added to 15 mL of α-terpineol and dispersed by sonication for 30 minutes. To this dispersion, 200 mg of a cellulose organic binder and 400 mg of glass frit were mixed and dispersed by sonication for 5 minutes. This dispersion was made into a paste by a three-roll mill. In this way, a CNT-containing paste was prepared.

  Next, the paste was screen-printed on a glass substrate on which an Al film was deposited so as to have a thickness slightly larger than 1 μm. This was baked at 500 ° C. for 1 hour in nitrogen to remove the organic binder. In this way, a cathode having an emitter formed on the cathode electrode was produced.

  Next, the emitter was peeled (peeling treatment). The peeling was performed by raising carbon nanotubes by attaching a peeling tape on the emitter and then peeling the tape. By repeating the peeling, the surface of the emitter is peeled off and the thickness of the emitter is reduced. Techni tape (trade name, manufactured by Technisco) was used as the peeling tape, and the thickness of the emitter was controlled by performing the peeling 0 to 8 times.

  The graph of FIG. 3 shows the relationship between the number of peelings (0 to 5 times) and the thickness of the emitter. In FIG. 3, the horizontal axis represents the length (mm) of the cathode electrode on which the emitter is formed, and the vertical axis represents the thickness (μm). In FIG. 3, (0), (1), (2), (3), (4), and (5) respectively indicate the emitters 0 times (no peeling), 1 time, 2 times, 3 times. It shows that it peeled 4 times and 5 times. In FIG. 3, the position where the thickness is suddenly increased is 5 to 25 mm, which is the position where the emitter is formed. The thickness of the emitter was measured with a laser step meter. The thickness of 0 μm or more is the thickness of the emitter. As shown in FIG. 3, the average thickness of the emitter is 1.245 μm when the number of peeling is 0 times, 1.039 μm when the number is once, 0.85 μm when the number is twice, 0.693 μm when the number is 3 times, and 0.33 μm when the number is 4 times. It was 0.195 μm at 342 μm and 5 times. Thus, the emitter was peeled off by about 0.2 μm per peeling.

FIG. 4 shows a photograph of the emitter after the peeling. In FIG. 4, 1 ^st , 2 ^nd , 3 ^rd , 4 ^th , 5 ^th , 6 ^th , 7 ^th , 8 ^th respectively represent the emitter once, twice, three times, four times, five times, It shows that it peeled 6 times, 7 times, and 8 times. As shown in FIG. 4, the amount of peeling of the emitter gradually increased according to the number of peeling, and the emitter gradually became thinner. The thickness of the emitter was about 0.19 μm or more after 5 times of peeling and smaller than 0.19 μm after 6 times. Specifically, the number of peeling was 6 to 8, and was about 0.05 μm or more and less than about 0.19 μm. All of the emitters having 1 to 8 peelings showed optical transparency. Specifically, the light transmittance in the case of six peelings was about 50 to 60%. The light transmittance (light transmittance) at 0 peeling (no peeling) was almost the same as that at 1 peeling.

(1-2. Production of anode)
Next, on a glass substrate on which an ITO film is formed by sputtering, a paste containing a phosphor is screen-printed with a dot pattern (dot (square) size: 1 mm, interval between each dot: 100 μm), and this is 450. Baked at ℃. In this manner, an anode having a phosphor layer formed on the anode electrode was produced.

(1-3. Production of field emission light-emitting device)
The cathode and the anode are arranged such that the anode substrate and the cathode substrate face each other, that is, the emitter side surface of the cathode and the phosphor layer side surface of the anode face each other. A field emission light-emitting device of Example 1 was produced. On the other hand, a field emission light-emitting device of a comparative example was produced in the same manner as in Example 1 except that an emitter (thickness: exceeding 1.5 μm) that did not exhibit optical transparency was used.

(2) Luminous efficiency The field emission light-emitting devices of Example 1 and Comparative Example were made to emit light by applying a voltage between the anode electrode and the cathode electrode at a vacuum degree of 4 × 10 ⁻⁶ Pa inside the device. It was. As a result, the light emission efficiency of the field emission light emitting device of Example 1 was improved as compared with the field emission light emission device of the comparative example. Specifically, in the case of a field emission light emitting device using the emitter with six peelings (light transmittance: 50 to 60%), the amount of extracted light is larger than that of the field emission light emitting device of the comparative example. Increased by 20%.

(3) Luminescent characteristics The luminous characteristics of the field emission light-emitting device of Example 1 were evaluated. The graph of FIG. 5 shows a current density (J) -electric field (E) curve in the field emission light-emitting device using the emitters having the respective thicknesses. In FIG. 5, the horizontal axis represents the electric field (kV / mm), and the vertical axis represents the current density (mA / cm ² ). In FIG. 5, 1 ^st , 2 ^nd , 3 ^rd , 4 ^th , 5 ^th , 6 ^th , 7 ^th , and 8 ^th indicate the number of peelings as in FIG. 4. As shown in FIG. 5, in the case of 7 or 8 peelings, the light emission characteristics were significantly deteriorated compared to the case of 6 peelings. Such a light emission characteristic is a finding that the present inventors have found for the first time. As described above, according to the present embodiment, when the thickness of the emitter having light transmittance is adjusted, the thickness of the emitter is set in consideration of the balance between the light emission efficiency and the light transmittance. It was confirmed that it was important to do.

  FIG. 6 shows a light emission photograph of a field emission light-emitting device using the emitters with the respective thicknesses. As shown in FIG. 6, the field emission light-emitting device of Example 1 had innumerable bright spots, and the number of bright spots was larger than that of the field emission light-emitting device of the comparative example. This result also shows that the light emission efficiency of the field emission light emitting device of Example 1 is improved as compared with the field emission light emission device of the comparative example. In addition, the number of bright spots was almost the same up to the number of peeling times of 6, but the number of bright spots was decreased at the number of peeling times of 7 or more compared to the number of peeling times of 6.

[Example 2]
In order to confirm the difference in luminous efficiency when the electrode structure is changed, the emitter is formed in a dot pattern, and the size of each dot in the dot pattern of the phosphor layer is determined from the dot size of the dot pattern of the emitter. A field emission light-emitting device of Example 2 was fabricated in the same manner as in Example 1 except that the size was increased. Specifically, in the production of the cathode, the dot pattern of the emitter is screen-printed with a dot (square) size: 2 mm and the interval between the dots: 1 mm, and in the production of the anode, the dot pattern of the phosphor layer Was screen-printed with a dot (square) size of 2.1 mm and an interval of each dot of 1 mm. This field emission light-emitting device was made to emit light in the same manner as in Example 1. This field emission light-emitting device was higher in luminous efficiency than the field emission light-emitting device of Example 1. As a result, it was confirmed that the electrons emitted from the emitter spread and the entire phosphor layer having a size larger than the emitter emitted light.

[Reference example]
A field emission light-emitting device of a reference example was fabricated in the same manner as in Example 1 except that the emitter thickness was changed and an emitter that did not exhibit optical transparency was used. Specifically, in the production of the cathode, the paste was applied a plurality of times on the glass substrate to increase the thickness of the coating, and the coating was baked. When the thickness of the emitter exceeds 1.5 μm, the emitter may not exhibit light transmittance. From this result, for example, as shown in Patent Document 5 (Japanese Patent Application Laid-Open No. 2006-278226), it is clear that even when the thickness of the emitter is 10 μm or less, the emitter may not exhibit optical transparency. It became. Further, as a result of measuring the thickness of the emitter after firing, the central portion tended to be slightly recessed as the emitter thickness was increased. For this reason, when the field emission light-emitting device of the reference example was made to emit light, when the thickness of the emitter exceeded 1.5 μm, the emission was uneven.

  A part or all of the above embodiment can be described as in the following supplementary notes, but is not limited to the following.

(Appendix 1)
An anode substrate having an anode electrode disposed on the substrate surface;
A cathode substrate having a cathode electrode disposed on the substrate surface;
The anode substrate and the cathode substrate are arranged such that the substrate surfaces face each other,
The anode substrate further includes a plurality of phosphor layers,
The plurality of phosphor layers are disposed between the anode substrate and the anode electrode and at least one on the anode electrode, spaced apart from each other,
The cathode substrate further includes an emitter,
The emitter is disposed on the cathode electrode;
The cathode electrode has light reflectivity;
A field emission light-emitting device, wherein the emitter is light transmissive.

(Appendix 2)
The field emission light-emitting device according to appendix 1, wherein a light reflecting layer having light reflectivity is disposed at a position where the cathode electrode is not disposed on the surface of the cathode substrate.

(Appendix 3)
The field emission light-emitting device according to appendix 1 or 2, wherein the emitter has a thickness in the range of 0.1 to 1.5 µm.

(Appendix 4)
4. The field emission light-emitting device according to any one of appendices 1 to 3, wherein a thickness of the emitter is in a range of 0.19 to 1 μm.

(Appendix 5)
The emitter is disposed inside the phosphor layer when viewed from a direction perpendicular to the substrate surface of the anode substrate, and the size of the phosphor layer is larger than the size of the emitter. The field emission light-emitting device according to any one of appendices 1 to 4.

(Appendix 6)
The plurality of phosphor layers are arranged to form a dot pattern;
6. The field emission light-emitting device according to any one of appendices 1 to 5, wherein a plurality of the emitters are arranged so as to form a dot pattern.

(Appendix 7)
The field emission light-emitting device according to appendix 6, wherein the plurality of emitters are arranged so as to have a one-to-one correspondence with the plurality of phosphor layers.

(Appendix 8)
The field emission according to any one of appendices 1 to 7, wherein the emitter includes at least one selected from the group consisting of carbon nanotubes, carbon nanohorns, carbon nanocoils, graphene sheets, and composites thereof. Light emitting device.

(Appendix 9)
An anode substrate providing step of providing an anode substrate having an anode electrode formed on the substrate surface;
A cathode substrate providing step of providing a cathode substrate in which a cathode electrode having light reflectivity is formed on the substrate surface;
A phosphor layer forming step of forming a plurality of phosphor layers at intervals between at least one of the anode substrate and the anode electrode and on the anode electrode;
Forming an emitter having optical transparency on the cathode electrode; and
2. The method of manufacturing a field emission light-emitting device according to claim 1, further comprising a substrate arranging step of arranging the anode substrate and the cathode substrate so that the substrate surfaces face each other.

(Appendix 10)
The field emission light-emitting device is the field emission light-emitting device according to appendix 2,
The electric field according to claim 9, further comprising a light reflecting layer forming step of forming a light reflecting layer having light reflectivity at a position where the cathode electrode is not disposed on the substrate surface of the cathode substrate. Manufacturing method of emission light emitting device.

(Appendix 11)
The field emission light-emitting device is the field emission light-emitting device according to appendix 3,
11. The method of manufacturing a field emission light-emitting device according to appendix 9 or 10, wherein, in the emitter forming step, the emitter is formed so that a thickness of the emitter is in a range of 0.1 to 1.5 μm.

(Appendix 12)
The field emission light-emitting device is the field emission light-emitting device according to appendix 4,
12. The field emission light-emitting device according to any one of appendices 9 to 11, wherein, in the emitter forming step, the emitter is formed so that the thickness of the emitter is in a range of 0.19 to 1 μm. Method.

(Appendix 13)
13. The method of manufacturing a field emission light-emitting device according to any one of appendices 9 to 12, wherein the emitter forming step includes a step of forming the light-transmitting emitter by peeling.

(Appendix 14)
The field emission light-emitting device is the field emission light-emitting device according to appendix 5,
In the emitter formation step, the emitter is formed inside the phosphor layer as viewed from a direction perpendicular to the substrate surface of the anode substrate,
14. The field emission according to any one of appendices 9 to 13, wherein in the phosphor layer forming step, the phosphor layer is formed so that a size of the phosphor layer is larger than a size of the emitter. Manufacturing method of light-emitting device.

(Appendix 15)
The field emission light-emitting device is the field emission light-emitting device according to appendix 6,
In the phosphor layer forming step, the phosphor layer is formed so as to form a dot pattern,
The method of manufacturing a field emission light-emitting device according to any one of appendices 9 to 14, wherein, in the emitter forming step, a plurality of the emitters are formed so as to form a dot pattern.

(Appendix 16)
The field emission light-emitting device is the field emission light-emitting device according to appendix 7,
16. The method of manufacturing a field emission light-emitting device according to appendix 15, wherein in the emitter formation step, the emitter is formed so as to correspond one-to-one with the plurality of phosphor layers.

(Appendix 17)
The field emission light-emitting device is the field emission light-emitting device according to appendix 8,
The emitter forming step includes a printing step of printing on the cathode electrode a paste containing at least one selected from the group consisting of carbon nanotubes, carbon nanohorns, carbon nanocoils, graphene sheets, and composites thereof. 17. A method for manufacturing a field emission light-emitting device according to any one of appendices 9 to 16,

(Appendix 18)
A light-emitting device comprising the field emission light-emitting device according to any one of appendices 1 to 8.

DESCRIPTION OF SYMBOLS 1 Anode substrate 2 Anode electrode 3 Cathode electrode 4 Phosphor layer 5, 25 Emitter 6 Cathode substrate 10, 20 Field emission light emitting device

Claims (10)

An anode substrate having an anode electrode disposed on the substrate surface;
A cathode substrate having a cathode electrode disposed on the substrate surface;
The anode substrate and the cathode substrate are arranged such that the substrate surfaces face each other,
The anode substrate further includes a plurality of phosphor layers,
The plurality of phosphor layers are disposed between the anode substrate and the anode electrode and at least one on the anode electrode, spaced apart from each other,
The cathode substrate further includes an emitter,
The emitter is disposed on the cathode electrode;
The cathode electrode has light reflectivity;
A field emission light-emitting device, wherein the emitter is light transmissive. 2. The field emission light-emitting device according to claim 1, wherein a light reflecting layer having light reflectivity is disposed at a position where the cathode electrode is not disposed on the surface of the cathode substrate. 3. The field emission light-emitting device according to claim 1, wherein the emitter has a thickness in a range of 0.1 to 1.5 [mu] m. The field emission light-emitting device according to claim 1, wherein the emitter has a thickness in a range of 0.19 to 1 μm. The emitter is disposed inside the phosphor layer when viewed from a direction perpendicular to the substrate surface of the anode substrate, and the size of the phosphor layer is larger than the size of the emitter. The field emission light-emitting device according to claim 1. The plurality of phosphor layers are arranged to form a dot pattern;
6. The field emission light-emitting device according to claim 1, wherein a plurality of the emitters are arranged to form a dot pattern. The field emission light-emitting device according to claim 6, wherein the plurality of emitters are arranged so as to correspond to the plurality of phosphor layers on a one-to-one basis. 8. The emitter according to claim 1, wherein the emitter includes at least one selected from the group consisting of carbon nanotubes, carbon nanohorns, carbon nanocoils, graphene sheets, and composites thereof. Field emission light-emitting device. An anode substrate providing step of providing an anode substrate having an anode electrode formed on the substrate surface;
A cathode substrate providing step of providing a cathode substrate in which a cathode electrode having light reflectivity is formed on the substrate surface;
A phosphor layer forming step of forming a plurality of phosphor layers at intervals between at least one of the anode substrate and the anode electrode and on the anode electrode;
Forming an emitter having optical transparency on the cathode electrode; and
2. The method of manufacturing a field emission light-emitting device according to claim 1, further comprising a substrate arranging step of arranging the anode substrate and the cathode substrate so that the substrate surfaces face each other.
A light emitting device comprising the field emission light emitting device according to claim 1.