JP4978846B2 - Light emitting device - Google Patents

Description

  The present invention relates to a light emitting device that outputs white light by exciting and emitting phosphors with electrons emitted from a cold cathode electron emission source.

  In recent years, in comparison with conventional light-emitting devices such as incandescent bulbs and fluorescent lamps, electrons emitted from a cold cathode electron emission source in a vacuum are caused to collide with the phosphor (light-emitting body) at high speed, thereby exciting the phosphor. Cold cathode field emission type light emitting devices have been developed, and are expected to be used as field emission lamps (FEL) and field emission display devices (FED).

  Among these light emitting devices, in the FED manufacturing process, various microprocesses of micron order according to the pixel size are generally used. For example, in the FED manufacturing process, a cathode (cathode electrode) is formed on an insulating substrate such as glass or ceramics by a well-known microprocess used for semiconductor chips such as sputtering and CVD. Further, a columnar molten material was formed directly on the insulating substrate or connected to a wiring layer formed on the surface of the insulating substrate, and a plurality of openings having a diameter of 10 to 100 μm were formed in the columnar molten material. A gate electrode is formed by fixing a thin metal plate having a thickness of 30 to 60 μm.

  On the other hand, in FEL specialized for lamp light sources and the like, there is no need to perform micron-order microfabrication such as FED on the cathode electrode and the like, and the diameter of the opening portion opened in the gate electrode is also small. A relatively large diameter on the order of millimeters is sufficient (for example, see Patent Document 1).

  Therefore, in the manufacture of FEL, it is possible to eliminate the micro process that requires a large amount of equipment cost, and to manufacture each functional component by combining the components that can be mass-produced only by the process in the atmosphere. Can expect down. For example, the cathode electrode and the gate electrode have a thickness of 0. It is conceivable that the FEL is manufactured at low cost by constituting individual functional parts each having a metal plate of about several mm as a base material and assembling them in a vacuum vessel.

JP 2006-339012 A

  In the FEL, white light is obtained by mixing the blue light of the first phosphor excited by an electron beam with the yellow light of the second phosphor and the yellow light of the second phosphor excited and emitted by the blue light. Yes.

  However, the white light obtained by mixing the blue light and the yellow light has a poor color rendering because the red component in the 600 to 700 nm region is insufficient. For this reason, for example, when the FEL is used for indoor lighting, the reproducibility of the color of human skin is deteriorated, and the difference from the case of viewing under sunlight is greatly discomforted.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a cold cathode field emission type light emitting device capable of improving color rendering.

A light emitting device according to a first aspect of the present invention includes a cathode layer having a cold cathode electron emission source and a phosphor layer that is hybridized with a plurality of types of phosphors that emit light by being excited by electrons emitted from the cold cathode electron emission source. And an anode electrode having a vacuum container. Each type of phosphor has a relationship of generating white light by the mixture of light emission, and each is dispersed on the surface of the light emitter layer. The phosphor layer is composed of a first phosphor that emits light in cyan by an electron beam and a second phosphor that emits light in red. The first phosphor is at least one selected from a cyan phosphor formed by co-activating Ag and Zn in ZnS and a cyan phosphor formed by co-activating Zn, Cu and Al in ZnS. . As the second phosphor, a phosphor that emits red light when excited by the cyan light of the first phosphor may be used. The phosphor layer may be a mixture of a third phosphor that emits yellow light and the first and second phosphors. Further, as the third phosphor, the first phosphor A phosphor that emits yellow light when excited by cyan light may be used.

  In the light-emitting device, cyan light is emitted when electrons collide with the first phosphor, red light is emitted when electrons collide with the second phosphor, and cyan light and red light are mixed. Composite white output light.

  In addition, by adding a third phosphor that emits yellow light to the phosphor layer, cyan light, red light, and yellow light are mixed, and white output light with higher color rendering can be obtained. . In addition, when a phosphor that is excited by cyan light of the first phosphor and emits red light is used as the second phosphor, red can be emitted more efficiently, and the third fluorescence When a phosphor that emits yellow light when excited by the cyan light of the first phosphor is used as the body, yellow can be emitted more efficiently.

The light emitting device according to the second aspect of the present invention includes a cathode electrode having a cold cathode electron emission source and an anode electrode having a light emitter layer in a vacuum vessel. The phosphor layer includes a first phosphor layer having a characteristic of emitting a cyan primary light in the first spectral region by exciting light emission from electrons emitted from a cold cathode electron emission source, and a first phosphor layer. A second phosphor layer having a characteristic of emitting red secondary light in the second spectral region by the emitted primary light, and a yellow tertiary light in the third spectral region by the primary light emitted from the first phosphor layer And a third phosphor layer having a characteristic of emitting light. The primary light, the secondary light, and the tertiary light are mixed according to the “additive color mixing principle” to emit white light.

  In the light emitting device, cyan light (primary light) is emitted when electrons collide with the first phosphor layer, and the primary light emitted from the first phosphor layer causes the second phosphor layer and the third phosphor layer to emit light. Red light (secondary light) and tertiary light are emitted, and cyan light, red light, and tertiary light (for example, yellow light) are mixed to obtain composite white output light.

  An advantage of the present invention is that the light emitting device can provide a composite white output light that is well-balanced with respect to color.

  That is, since the generated white light contains a red component, white light having a desired color temperature can be realized in applications where a good color balance is required. For example, since the reproducibility of human skin color is improved, it is suitable for indoor lighting.

  The present inventor has made sincere efforts to develop a cyan phosphor capable of obtaining a high illuminance particularly when used in an FED. As a result, ZnS (zinc sulfide) and Ag (silver) and Zn (zinc) are both used. Activate (ZnS as a base material and Ag and Zn as a coactivator) or ZnS to co-activate Cu (copper), Al (aluminum) and Zn (zinc) (ZnS as a base material, Al, Cu and Zn) To be a co-activator). Therefore, by causing electrons to collide with the blue (cyan) phosphor close to green, excitation light can be emitted with a higher illuminance than a general blue phosphor.

  Furthermore, when Ag and Zn are activated in ZnS, the concentration of Ag with respect to ZnS is 0.001 to 0.05 mol%, preferably the concentration of Ag is about 0.015 mol%, and the concentration of Zn is 0.0025 to 0. 0.05 mol%, preferably the Zn concentration is 0.03 mol%.

  Further, when Cu, Al and Zn are co-activated in ZnS, the concentration of Cu is 0.001 to 0.03 mol%, the concentration of Al is 0.001 to 0.03 mol%, and the concentration of Zn is 0.001 to 0.001. It was found that 0.05 mol% is preferable.

  These phosphors emit light in a slightly greenish blue color when excited and emitted by electrons. That is, it has been found that light is emitted in a slightly longer wavelength band (440 to 530 nm) than the pure blue wavelength band (410 to 465 nm), and the luminance is improved to about 160% compared to blue. FIG. 4 shows an example of the comparison results of the cathodoluminescence spectra of the blue phosphor (ZnS: Ag) and the cyan phosphor (ZnS: Cu, Al, Zn).

  Next, a first embodiment of a light emitting device including a cyan phosphor according to the present invention will be described with reference to the drawings.

  FIG. 1 is a basic configuration diagram of a light emitting device according to a first embodiment using a cyan phosphor according to the present invention, and FIG. 2 is a schematic diagram showing an enlarged luminescent layer. In FIG. 2, the cyan phosphor particles 17 are shown larger than the red phosphor particles 18 in order to distinguish between the cyan phosphor particles 17 and the red phosphor particles 18, but the magnitude relationship between them is shown in FIG. It is not limited to.

  As shown in FIG. 1, a light emitting device 1 in the present embodiment is a light emitting device used as, for example, a planar field emission type white illumination lamp, and a vacuum container in which glass substrates 2 and 3 are arranged to face each other at a predetermined interval. 4 has a basic configuration in which a cathode electrode 5, a gate electrode 10, and an anode electrode 15 are arranged in order from the base surface side to the light projecting surface side.

  The cathode electrode 5 is made of a conductive material formed on the glass substrate 2 serving as the base surface. For example, a metal such as aluminum or nickel is deposited by vapor deposition or sputtering, or a silver paste material is applied and dried. It is formed by firing. On the surface of the cathode electrode 5, an emitter material such as a carbon nanotube, a carbon nanowall, a spint type micro cone, a metal oxide whisker or the like is applied in a film shape to form a cold cathode electron emission source 6.

  In this embodiment, the cold cathode electron emission source 6 is patterned for each predetermined region, and a cathode mask 7 covering the cathode electrode 5 is arranged around the patterned region (electron emission region).

  The gate electrode 10 is composed of a flat plate member having an opening 11 through which electrons emitted from the cold cathode electron emission source 6 pass. Specifically, the gate electrode 10 has a simple mechanical structure in which a plurality of openings 11 corresponding to the pattern region of the cold cathode electron emission source 6 are formed on a conductive metal plate such as a nickel material, a stainless material, or an amber material. The main part is formed by processing or the like. The opening 11 of the gate electrode 10 is formed as a circular hole formed, for example, the same as or slightly larger than the pattern region of the cold cathode electron emission source 6 formed in a land shape. As a result, almost all electrons emitted from the cold cathode electron emission source 6 can be passed to be effective electrons contributing to light emission, reducing power loss at the gate electrode 10 and realizing a lossless gate. It is possible.

  The anode electrode 15 is made of a transparent conductive film (for example, ITO film) disposed on the back surface side of the glass substrate 3 serving as a light projecting surface, and cold cathode electron emission is performed on the surface facing the gate electrode 10 (cathode electrode 5). A phosphor layer 16 is formed that is excited and emitted by electrons emitted from the source 6.

  The light emitter layer 16 is composed of a plurality of types of phosphors having different wavelength bands of light that emits excitation light, and generates white light by mixing light of excitation light from these phosphors. The light emitting layer 16 is composed of a cyan phosphor that emits light by exciting cyan light and a red phosphor that emits light by exciting red light that is complementary to the cyan light. In the present embodiment, as the cyan phosphor, at least one of a phosphor obtained by co-activating Ag and Zn in ZnS or a phosphor obtained by co-activating Zn, Cu and Al in ZnS is used. As the red phosphor, a (Ca, Sr) S-based red phosphor containing calcium sulfide (CaS) is used, and this red phosphor is broad in a wavelength band of 580 to 720 nm due to excitation emission by electrons. Emits red light with high luminous efficiency. As the red phosphor, in addition to the sulfide phosphor, for example, sialon phosphors disclosed in JP-A-2002-36355 and JP-A-2003-336059, and JP-A-2003-96446 are disclosed. Other nitride phosphors such as the disclosed lanthanum silicon nitride phosphor activated cerium ions may be used.

  As shown in FIG. 2, specifically, the phosphor layer 16 includes cyan phosphor particles 17 formed by crystallizing cyan phosphors and red phosphor particles 18 formed by crystallizing red phosphors. It is formed by mixing with. The phosphor particles 17 and 18 are dispersed on the surface of the phosphor layer 16, and these phosphor particles 17 and 18 are electrons emitted from the cold cathode electron emission source 6 in the vacuum container 4. Are directly exposed to each.

  The light emitter layer 16 may further contain a dispersion material. In this case, it is preferable that the ratio of the dispersion material with respect to the light emitter layer 16 is 5 to 25% by weight.

  For such a phosphor layer 16, for example, a red phosphor solution and a cyan phosphor solution are sequentially applied onto the anode electrode 15 by screen printing or the like, and each phosphor is crystallized through a thermal process such as annealing. Is formed. At that time, the concentration and the coating amount of each phosphor solution, the conditions of the heat process, etc. are set to appropriate values, and the phosphor particles 17 and 18 are arranged on the anode electrode 15 with a predetermined roughness, whereby both fluorescences are obtained. The body particles 17 and 18 can be dispersed on the surface of the phosphor layer 16.

  Then, for example, the cyan phosphor particles 17 are excited by being directly exposed to the electrons emitted from the cold cathode electron emission source 6 to emit cyan light GB. Similarly, the red phosphor particles 18 are excited by being directly exposed to electrons emitted from the cold cathode electron emission source 6 and emit red light R. The cyan light GB and the red light R are mixed on the light-projecting surface side of the glass substrate 3, whereby the light-emitting device 1 efficiently generates high-intensity white light W.

  That is, by dispersing the cyan phosphor particles 17 and the red phosphor particles 18 on the surface of the phosphor layer 16, the phosphor particles 17 and 18 can be directly exposed to electrons. Compared to the case where the phosphor layer 17 is formed by superimposing the phosphor particles 17 and the red phosphor particles 18 in separate layers, both the cyan light GB and the red light R can be efficiently emitted by electronic excitation. .

  According to the present embodiment, the red phosphor particles 18 are also excited by the cyan light GB emitted from the neighboring cyan phosphor particles 17 and can emit the red light R. In this case, since the red phosphor particles 18 are excited not only by the electron beam but also by the cyan light GB, when the part of the electron-excited cyan light GB passes through the phosphor layer 16, the red phosphor particles 18 Even in the case of being blocked by 18, the cyan light GB can be effectively used to improve the luminance of the red light R, and the white light W is obtained by the additive color mixture of the cyan light GB and the red light R. Yes. That is, since the cyan phosphor does not emit light to the cyan light GB by the red light R of the red phosphor that emits light by electron beam excitation, the arrangement of the phosphor particles 17 and 18 in consideration of that is not possible. It is indispensable in the phosphor layer 16.

  As described above, compared with the case where white light emission is realized due to the complementary color relationship between blue and yellow, the red component in the red region which is insufficient is added to the white light emission, so that the color rendering is improved and the desired color temperature is appropriately set. White light emission can be realized. Further, a light emitting layer may be formed by adding a yellow phosphor (for example, a yttrium, aluminum, garnet (YAG) yellow phosphor) to the above. This makes it possible to emit white light with a wide color temperature due to a mixture of cyan, red, and yellow, and to reproduce human skin color that is almost ideal for general indoor lighting. Can do.

  Next, a second embodiment of the light emitting device of the present invention will be described with reference to the drawings. FIG. 3 is an enlarged schematic view showing a light emitting layer of the light emitting device according to the second embodiment using the cyan phosphor according to the present invention. In addition, this embodiment and the said 1st Embodiment differ in the structure of the light-emitting body layer 16, and a detailed description is abbreviate | omitted about another common structure. In FIG. 3, the sizes of the phosphor particles 17, 18 and 19 are made different in order to distinguish the cyan phosphor particles 17, the red phosphor particles 18 and the yellow phosphor particles 19. The magnitude relationship is not limited to this. Moreover, although the thickness of the 1st fluorescent substance layer 20, the 2nd fluorescent substance layer 21, and the 3rd fluorescent substance layer 22 is shown substantially equal, the thickness of each layer is not limited to this.

  The phosphor layer 16 of the present embodiment includes a first phosphor layer 20, a second phosphor layer 21, and a third phosphor layer 22. Each phosphor layer 20, 21, 22 is a thin film containing a single kind of phosphor particle, the second phosphor layer 21 covers the anode electrode 15, and the third phosphor layer 22 is formed on the surface thereof. And the first phosphor layer 20 is further laminated on the surface thereof. That is, the first phosphor layer 20 is positioned closest to the cold cathode electron emission source side, the second phosphor layer 21 is positioned closest to the anti-cold cathode electron emission source side, and the third phosphor layer 22 is positioned as the first phosphor. Located between the layer 20 and the second phosphor layer 21. The order in which the second phosphor layer 21 and the third phosphor layer 22 are stacked is arbitrary, the third phosphor layer 22 is disposed closest to the anti-cold cathode electron emission source side, and the second phosphor layer 21 is You may arrange | position between the one fluorescent substance layer 20 and the 3rd fluorescent substance layer 22. FIG.

  The first phosphor layer 20 includes cyan phosphor particles 17 and is excited to emit light by electrons emitted from the cold cathode electron emission source 6 to emit cyan in the first spectral region (wavelength band: 420 to 630 nm). The primary light is emitted. The second phosphor layer 21 includes red phosphor particles 18, and the red phosphor particles 18 are excited by the primary light emitted from the first phosphor layer 20, and the second spectral region (wavelength band: 580 to 720 nm). Of red secondary light. The third phosphor layer 22 includes yellow phosphor particles (for example, yttrium-aluminum-garnet (YAG) -based yellow phosphor particles) 19, and the yellow phosphor is generated by the primary light emitted from the first phosphor layer 20. The particles 19 are excited to emit yellow tertiary light in the third spectral region (wavelength band: 500 to 650 nm). The primary light, the secondary light, and the tertiary light are mixed according to the “additive color mixing principle” to emit white light. Note that the light emitter layer 16 is preferably configured so that the average color rendering index of the composite output light resulting from the combination of the primary light, the secondary light, and the tertiary light is greater than 80.

  According to the above configuration, cyan light (primary light) is emitted when electrons collide with the first phosphor layer 20, and the second phosphor layer 21 and the third phosphor light are emitted by the primary light emitted from the first phosphor layer 20. Red light (secondary light) and yellow light (tertiary light) are emitted from the phosphor layer 22, and cyan white light, red light, and yellow light are mixed to obtain a composite white output light. Similarly, the red component in the red region is added to the white light emission, so that the color rendering is improved and the white light emission with a desired color temperature can be realized as appropriate.

  In each of the above embodiments, an example in which the phosphor layer is formed using cyan phosphor and red phosphor, or cyan, red and yellow is described, but the present invention is not limited to this. Judging from the chromaticity diagram, white may be realized by mixing three colors of blue, green, and red emitted by electron beam excitation. However, the excitation of the phosphor is not effective by itself, and since the luminance of the light emission as white is insufficient, the second and third phosphors are further generated depending on the colors emitted by the electron beam excitation, Or the white illumination of the optimal illumination use which can select color temperature is implement | achieved by the combination with the spectrum (photoluminescence) which 2nd and 3rd fluorescent substance excites light emission.

  As an example, the method for synthesizing the cyan phosphor and the red phosphor of this patent is shown below, but the method for synthesizing these phosphors is not particularly limited.

[Example 1]
About raw materials After filling zinc sulfide powder as a raw material into a quartz boat, the mixture was allowed to stand in the center of the silicon carbide furnace body, and after adjusting the furnace atmosphere, heat treatment was performed at a predetermined temperature and time. As the zinc sulfide, high and low crystallinity particles having a secondary particle size of 2 to 3 μm were handled. Further, in order to prevent oxidation of zinc sulfide, the inside of the furnace was set to a nitrogen atmosphere (flow rate: 100 ml / min), and heat treatment was performed at 580 ° C. to 1080 ° C. for 2.5 hours.

  The crystal phase of zinc sulfide as a raw material partially contained high-temperature stable hexagonal crystals, but it was confirmed by powder X-ray diffraction that it was mainly low-temperature stable cubic crystals. I left it. However, regardless of the difference in crystallinity, at a temperature exceeding 580 ° C., the powder X-ray diffraction peak became sharp, and at 980 ° C., the ratio of the hexagonal system gradually increased. It was also found that only hexagonal crystals were obtained at a phase transition temperature of 1020 ° C. or higher.

  Table 1 shows the difference in specific surface area due to the difference in raw materials.

[Table 1]
Heat treatment temperature Specific surface area (m ² / g)
High crystalline sample Low crystalline sample
Before treatment 13.1 32.2
580 ° C 2.8 7.9
680 ° C 1.3 5.6
780 ° C 0.9 1.7
880 ° C 0.7 0.8
980 ° C 0.6 0.7
1080 ° C 0.2 0.2

Beyond 1020 ° C., the particle size suddenly increased and reached about 10 μm. In general, it has been pointed out that the presence of a hexagonal phase in the cubic phase has problems such as poor color purity, a large variation in particle size distribution, and a decrease in luminance of the phosphor.
About activation Using copper sulfate (CuSO ₄ .5H ₂ O), weighed zinc sulfide (ZnS) so as to have a predetermined ratio of Cu, and wet mixed with ethanol. In addition, the inside of the furnace was made into a sulfur gas atmosphere accompanying the decomposition of carbon disulfide in consideration of the oxidation prevention and the reduction of sulfur components accompanying the temperature rise. As the firing temperature, heat treatment was performed for 2.5 hours at 880 ° C. to 980 ° C. (below the transition temperature from cubic to hexagonal).

From the result of the diffuse reflection spectrum, an absorption edge was found around 340 nm in the phosphor obtained by baking at 980 ° C. This was confirmed to correspond to a band gap of a cubic phase of 3.7 eV. From the measurement of the fluorescence spectrum, it was found that these phosphors can observe green light emission at around 530 nm by excitation at 370 nm. As a result of changing the Cu ²⁺ concentration from 0.005 mol% to 0.05 mol%, the luminance showed a maximum value in the vicinity of 0.015 mol%. From this, it is considered that “concentration quenching” occurs at> 0.015 mol%. The emission center in ZnS emitting green light is considered to be formed by Cu ⁺ substituted for Zn ²⁺ and vacancy of S ²⁻ .

Therefore, co-activation of Al ³⁺ ions in the cyan phosphor contributes to the stability of Cu ⁺ . As a result, it was found that about 0.02 mol% of Al ³⁺ is the optimum concentration. Beyond this, it was confirmed that concentration quenching was caused by the Auger effect.

[Example 2]
A flux (flux) was used for the purpose of improving crystallinity of zinc sulfide and suppressing grain growth and further growth of the hexagonal phase. As a flux, halide, carbonate, sulfate, etc. were added to the zinc sulfide raw material or the phosphor obtained in Example 2, for example, by several to 10% (optimum value is about 1 mol%). This was weighed at a predetermined ratio, then wet-mixed with ethanol and dried. The inside of the furnace was in a nitrogen atmosphere to prevent oxidation, and heat treatment was performed at 680 to 1080 ° C. for 2.5 hours. The following compounds were used as the flux.

_{NaCl, NaBr, KCl, KBr,} KI, LiCl, MgCl 2, CaCl 2, SrCl 2, BaCl 2, Na 2 CO 3, K 2 CO 3, Na 2 SO 4, ZnCl 2, AlCl 3, CuCl 2, CuSO 4 , Cu (CH ₃ CO ₂ ) ₂ , AgCl.

As a result, phosphor grain growth was remarkable in BaCl ₂ , SrCl _{2, and the} like containing an alkaline earth metal that produces a sulfide having a melting point higher than the heat treatment temperature. Further, when NaCl, NaBr, KCl, KBr, KI, LiCl containing an alkali metal is compared with Na ₂ CO ₃ , K ₂ CO ₃ , or Na ₂ SO ₄ , phosphor grain growth is recognized regardless of which is used. However, compared to chloride, other salts showed poor dispersibility and some particles tended to sinter and aggregate easily. The above-mentioned flux has no problem in terms of grain growth, which is a function of the flux, but none of the effects of suppressing the growth of the hexagonal phase has been confirmed.

On the other hand, for CuCl ₂ , CuSO ₄ , Cu (CH ₃ CO ₂ ) ₂ , no hexagonal phase was generated even when the processing temperature was increased to 1080 ° C. Similarly, the same effect was obtained with AgCl. Therefore, it was found that these are most suitable as an issuance-centered activation method rather than flux (although the effect of flux can be expected to some extent).

  Therefore, activation of the phosphor produced in the present invention is performed by a combination of a salt containing an activation element and a flux containing an alkaline earth metal, and precise control of activation conditions (firing temperature, time, amount, etc.) is performed. completed.

Example 3
As for the red phosphor CaS: Eu ²⁺ or (Ca, Sr) S: Eu ²⁺ , as in Example 1 or Example 2, CaS or (Ca, Sr) S, which becomes a mother crystal in advance, is replaced with alkaline earth. It was prepared by a method by sulfurization of a metal oxide or carbonate, or a method by reduction of sulfate.

Next, 0.1 to 0.4 mol% of a compound containing divalent Eu ions, for example, EuS, is added to the mother crystal raw material, and this is filled in an alumina boat. Next, this boat was placed in an alumina reaction tube, and argon + H ₂ (4%) gas was introduced, and heat treatment was performed at 850 to 1150 ° C. for 2.0 hours. Further, a salt containing an alkali such as KCl was added as a flux, and grain growth was performed to produce phosphor particles of 3 to 10 μm. The result of this cathodoluminescence spectrum is shown in FIG. 5 together with that of the blue phosphor.

1 is a basic configuration diagram of a light emitting device according to a first embodiment. It is a schematic diagram which expands and shows the light-emitting body layer of 1st Embodiment. It is a schematic diagram which expands and shows the light-emitting body layer of 2nd Embodiment. It is a figure which shows the comparison of the cathodoluminescence spectrum of blue fluorescent substance (ZnS: Ag) and cyan fluorescent substance (ZnS: Cu, Al, Zn). It is a figure which shows the result of the cathode luminescence of a blue fluorescent substance and a red fluorescent substance (CaS: Eu).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Light-emitting device 2, 3 ... Glass substrate 4 ... Vacuum container 5 ... Cathode electrode 6 ... Cold-cathode electron emission source 7 ... Cathode mask 10 ... Gate electrode 11 ... Opening part 15 ... Anode electrode 16 ... Phosphor layer 17 ... Cyan color Phosphor particles 18 ... red phosphor particles 19 ... yellow phosphor particles 20 ... first phosphor layer 21 ... second phosphor layer 23 ... third phosphor layer

Claims (8)

A cathode electrode having a cold cathode electron emission source;
An anode electrode having a phosphor layer mixed with a plurality of types of phosphors excited and emitted by electrons emitted from the cold cathode electron emission source, and provided in a vacuum vessel,
Each type of phosphor has a relationship of generating white light by mixing light of each excitation light, and each is dispersed on the surface of the phosphor layer,
The phosphor layer is composed of a first phosphor that emits light in cyan and a second phosphor that emits light in red .
The first phosphor is at least one selected from a cyan phosphor formed by co-activating Ag and Zn in ZnS and a cyan phosphor formed by co-activating Zn, Cu, and Al in ZnS. There is a light emitting device. The light-emitting device according to claim 1,
The second phosphor is a red phosphor and (Ca, Sr) light emitting device which is characterized in that at least one selected from a red phosphor including Eu ²⁺ in S containing Eu ²⁺ to CaS. A cathode electrode having a cold cathode electron emission source;
An anode electrode having a phosphor layer mixed with a plurality of types of phosphors excited and emitted by electrons emitted from the cold cathode electron emission source, and provided in a vacuum vessel,
Each type of phosphor has a relationship of generating white light by mixing light of each excitation light, and each is dispersed on the surface of the phosphor layer,
The phosphor layer includes a first phosphor that emits and emits light in cyan, a second phosphor that emits and emits red light, and Ce ³⁺ activated yttrium aluminum garnet (YAG) that emits and emits yellow light . A light-emitting device characterized by being hybridized with three phosphors . The light-emitting device according to claim 3,
The first phosphor is one selected from a cyan phosphor formed by co-activating Ag and Zn in ZnS and a cyan phosphor formed by co-activating Zn, Cu and Al in ZnS. A light emitting device characterized by that. The light-emitting device according to claim 3 or 4 ,
The second phosphor is a red phosphor and (Ca, Sr) light emitting device which is characterized in that at least one selected from a red phosphor including ^{Eu 2+} in S containing ^{Eu 2+} to CaS. The light-emitting device according to any one of claims 1 to 5,
At least one of the phosphors has a characteristic of being excited to emit light even by excitation light from other types of the phosphors . A cathode electrode having a cold cathode electron emission source;
An anode electrode having a phosphor layer, and a vacuum vessel,
The phosphor layer includes a first phosphor layer having a characteristic that emits cyan primary light in a first spectral region by exciting light emission by electrons emitted from the cold cathode electron emission source, and the first fluorescence. A second phosphor layer having a characteristic of emitting red secondary light in the second spectral region by the primary light emitted from the body layer; and a third phosphor region in the third spectral region by the primary light emitted from the first phosphor layer. A third phosphor layer having a characteristic of emitting yellow tertiary light,
A light-emitting device that emits white light by mixing the primary light, the secondary light, and the tertiary light in accordance with the principle of additive color mixing . The light-emitting device according to claim 7 ,
The light emitting device according to claim 1, wherein the composite output light resulting from the combination of the primary light, the secondary light, and the tertiary light has an average color rendering index greater than 80 .

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