JP2014165062A - Phosphor substrate and display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a phosphor substrate capable of efficiently extracting light emitted from a phosphor layer to the outside.SOLUTION: A phosphor substrate 100 includes: a light transmitting substrate 101; a light transmitting intermediate layer 107 formed on one side 101a of the substrate 101; a phosphor layer 102 formed on the intermediate layer 107; and a light-scattering partition wall 111 vertically arranged on the one surface 101a of the substrate 101 while surrounding the side face of the intermediate layer 107.

Description

  The present invention relates to a phosphor substrate and a display device including the phosphor substrate.

  A phosphor substrate is known in which a phosphor layer is formed on a substrate such as glass, and light incident from the outside is color-converted by the phosphor layer and emitted from the substrate. The phosphor substrate may be used as color conversion means for a liquid crystal display device. For example, a phosphor-excited color conversion type liquid crystal display device using a blue light-emitting diode (LED) or a near-ultraviolet light-emitting diode (LED) as a backlight and arranging a phosphor layer in a portion corresponding to a color filter is a color display. Compared with a normal liquid crystal display device using a filter, the light use efficiency is high and a bright display is possible (for example, see Patent Document 1).

JP 2008-10298 A

  In this type of phosphor substrate, the phosphor layer is usually formed so as to overlap the substrate on the light extraction side. In general, since the refractive index of the substrate material (glass substrate or the like) and the binder resin are close, the difference between the incident angle and the refractive angle is small at the interface between the phosphor layer and the substrate. On the other hand, since there is a large difference in refractive index at the interface between the substrate and air (outside air), light emitted at an angle larger than the total reflection angle determined by the difference in refractive index between the two is totally reflected and guided through the substrate. The emitted light cannot be efficiently emitted outside the substrate.

  An object of the present invention is to provide a phosphor substrate that can efficiently extract light emitted from a phosphor layer to the outside, a display device including the phosphor substrate, and the like.

  The phosphor substrate of the present invention includes a light transmissive substrate, a light transmissive intermediate layer formed on one surface of the substrate, a phosphor layer formed on the intermediate layer, and a side surface of the intermediate layer. And a light-scattering partition wall standing on one surface of the substrate.

  Here, “light-transmitting” refers to the property of transmitting at least light having the emission main wavelength of the phosphor layer. “Light scattering property” refers to a property of scattering at least light having a main emission wavelength of the phosphor layer.

  The surface of the intermediate layer facing the substrate is an interface between the substrate and the intermediate layer, and the phosphor layer at a position facing the center of the interface when viewed from the normal direction of the substrate is the center of the phosphor layer. At least part of the light having the emission main wavelength of the phosphor layer emitted from the central portion of the phosphor layer toward the outer edge of the interface is scattered by the barrier ribs. Without reaching the substrate and entering the interface between the substrate and the air layer at an angle smaller than the critical angle determined by the refractive index difference between the substrate and the air layer outside the substrate.

  Here, “the surface of the intermediate layer facing the substrate as the interface between the substrate and the intermediate layer” means that the surface of the intermediate layer on the substrate side is defined as the interface between the substrate and the intermediate layer. The intermediate layer is not necessarily in contact with the substrate, and the case where the intermediate layer and the substrate are separated via another member such as a color filter is also included in the technical scope of the present invention.

  The “outer edge part of the interface” means a position as close as possible to the outer edge part of the interface within a range where direct light from the phosphor layer toward the substrate passes through the interface and is not shielded by the partition walls. Direct light refers to light that is directly incident on the substrate from the phosphor layer without being scattered by the barrier ribs. In the case where a light shielding layer is formed at the interface between the barrier rib and the substrate, the interface is as far as possible within the range where the direct light from the phosphor layer toward the substrate passes through the interface and is not shielded by the barrier rib and the light shielding layer. The position near the outer edge of the interface is defined as the outer edge of the interface.

  The height of the intermediate layer is h, the shortest length from the center of the interface to the outer edge of the interface is w / 2, the aspect ratio h / w of the intermediate layer is A, and the total emission amount of the phosphor layer is P, the amount of light transmitted through the substrate and extracted outside the substrate, E, the extraction efficiency E / P is η, the total light reflectance of the partition wall is R, and the extraction efficiency η when R = r is When η <r>, the extraction efficiency η <r> when A = a is η <r / a>, and the maximum value of A that satisfies η <r / a> ≧ η <r / 0> is Amax <r > And R may satisfy the relationship of 100% ≧ R ≧ 70% and Amax <r >> A> 0.

  The intermediate layer may have an average transmittance in a light emission wavelength region of the phosphor layer higher than an average transmittance in a wavelength region other than the light emission wavelength region of the phosphor layer.

  The phosphor layer may include a light transmissive binder resin and a phosphor.

  The phosphor layer and the intermediate layer may have substantially the same refractive index.

  The binder resin and the intermediate layer may be made of the same material.

  The refractive index of the phosphor layer may be smaller than the refractive index of the intermediate layer.

  The difference in refractive index between the phosphor layer and the intermediate layer may be 0.3 or less, more preferably 0.1 or less.

  A wavelength selection layer that transmits excitation light that excites the phosphor layer and reflects fluorescence generated in the phosphor layer by the excitation light may be formed on the phosphor layer.

  The partition may partition the phosphor layer into a plurality of regions.

  The phosphor layer may include one or more types of phosphors, and the emission main wavelength of the first phosphor among the one or more types of phosphors may be 500 to 560 nm.

  Of the plurality of regions, only the first phosphor may be accommodated in the first region.

  In the first section, a plurality of types of phosphors having different emission main wavelengths within a range of 500 to 560 nm may be accommodated as the first phosphor.

  Between the said board | substrate and the said fluorescent substance layer in said 1st division, it has the maximum value of the transmittance | permeability in the wavelength range of 500-560 nm, and also the transmittance | permeability of the light of the wavelength range of 500-560 nm is 430- You may further provide the filter layer larger than the maximum transmittance | permeability of the light of each wavelength range of 490 nm and 600-650 nm.

  The phosphor layer may include a second phosphor made of a phosphor material different from the first phosphor, and the emission main wavelength of the second phosphor may be 600 to 650 nm. .

  Of the plurality of regions, only the second phosphor may be accommodated in the second region.

  In the second section, a plurality of types of phosphors having different emission main wavelengths within a range of 600 to 650 nm may be accommodated as the second phosphor.

  Between the said board | substrate and the said fluorescent substance layer in said 2nd division, it has the maximum value of the transmittance | permeability in the wavelength range of 600-650 nm, and also the transmittance | permeability of the light of the wavelength range of 600-650 nm is 430-300. You may further provide the filter layer larger than the maximum transmittance | permeability of the light of each wavelength range of 490 nm and 500-560 nm.

  The phosphor layer may include a third phosphor made of a phosphor material different from the first phosphor, and the emission main wavelength of the third phosphor may be 430 to 490 nm. .

  Of the plurality of regions, only the third phosphor may be accommodated in the third region.

  In the third section, a plurality of types of phosphors having different emission main wavelengths within a range of 430 to 490 nm may be accommodated as the third phosphor.

  Between the said board | substrate and the said fluorescent substance layer in said 3rd division, it has the maximum value of the transmittance | permeability in the wavelength range of 430-490 nm, and also the transmittance | permeability of the light of the wavelength range of 430-490 nm is 500- You may further provide the filter layer larger than the maximum transmittance | permeability of the light of each wavelength range of 560 nm and 600-650 nm.

  The phosphor layer may include light scattering particles.

  Of the compartments of the plurality of regions, the third compartment may contain only the light scattering particles.

  Between the said board | substrate and the said fluorescent substance layer in said 3rd division, it has the maximum value of the transmittance | permeability in the wavelength range of 430-490 nm, and also the transmittance | permeability of the light of the wavelength range of 430-490 nm is 500- You may further provide the filter layer larger than the maximum transmittance | permeability of the light of each wavelength range of 560 nm and 600-650 nm.

  The excitation light for exciting the phosphor layer may have a wavelength range of 400 nm to 1500 nm.

  The light emitting device of the present invention includes the phosphor substrate of the present invention and a light source that emits excitation light that excites the phosphor layer.

  The light source may be an LED element.

  The light source may be an organic EL element.

  A liquid crystal layer for controlling the incidence of the excitation light may be further disposed between the phosphor substrate and the light source.

  The display device of the present invention includes the light emitting device of the present invention.

  The illumination device of the present invention includes the light emitting device of the present invention.

  The solar cell module of the present invention includes the phosphor substrate of the present invention and a photoelectric conversion element.

  ADVANTAGE OF THE INVENTION According to this invention, the phosphor substrate which can take out the light emitted from the fluorescent substance layer efficiently outside, a display apparatus provided with this fluorescent substance substrate, etc. can be provided.

It is a cross-sectional schematic diagram of the phosphor substrate of the first embodiment. It is a cross-sectional schematic diagram for demonstrating the effect | action of the phosphor substrate of 1st Embodiment in the comparison with the phosphor substrate of a comparative example. It is a figure which shows the incident angle and outgoing angle of the light in each interface of an intermediate | middle layer, a board | substrate, and air. It is a figure which shows correlation with the refractive index of an intermediate | middle layer, and a critical angle. It is a cross-sectional schematic diagram which shows the propagation state of the light in the fluorescent substance board | substrate which is not provided with a partition. It is a cross-sectional schematic diagram which shows the propagation state of the light in the fluorescent substance board provided with the partition. It is the perspective view and cross-sectional schematic diagram of the fluorescent substance layer and intermediate | middle layer of the area | region for one division divided by the partition. It is a figure which shows correlation with the refractive index of an intermediate | middle layer, and the aspect-ratio of an intermediate | middle layer. 3 is a schematic cross-sectional view of phosphor substrates of Comparative Example 3, Comparative Example 4 and Example 1. FIG. It is a figure which shows the reason for the taking-out efficiency of the comparative example 4 not improving. It is a figure which shows the correlation of the reflectance of a partition, and extraction efficiency. FIG. 12 is a diagram in which the data in FIG. 11 is plotted with the horizontal axis as the aspect ratio of the intermediate layer and the vertical axis as the extraction efficiency. FIG. 12 is a diagram in which the data in FIG. 11 is plotted with the horizontal axis as the aspect ratio of the intermediate layer and the vertical axis as the extraction efficiency. It is the figure which plotted the optimal value of the aspect-ratio of the intermediate | middle layer, and the upper limit of the aspect-ratio of the intermediate | middle layer on the horizontal axis | shaft the reflectance of the partition. It is a cross-sectional schematic diagram of the display apparatus provided with the phosphor substrate of the second embodiment. It is a graph which shows an example of the emission spectrum of a green fluorescent substance, and the transmission spectrum of a green filter. It is a cross-sectional schematic diagram of the phosphor substrate of the third embodiment. It is a cross-sectional schematic diagram of the phosphor substrate of the fourth embodiment. It is a cross-sectional schematic diagram of the display apparatus provided with the phosphor substrate of the fifth embodiment. It is the cross-sectional schematic diagram and the plane schematic diagram of the fluorescent substance substrate of 6th Embodiment. It is the cross-sectional schematic diagram and planar schematic diagram of the fluorescent substance substrate of 7th Embodiment. It is a cross-sectional schematic diagram of the light-emitting device provided with the fluorescent substance substrate of 8th Embodiment. It is a cross-sectional schematic diagram which shows the light-emitting device provided with the fluorescent substance substrate of 9th Embodiment. It is a cross-sectional schematic diagram of the solar cell module provided with the fluorescent substance substrate of 10th Embodiment. It is a graph which shows the wavelength dispersion characteristic of the photoelectric conversion efficiency of a solar cell element. It is a graph which shows the effect which applied the fluorescent substance substrate to the solar cell. It is a graph which shows the component which a red fluorescent substance absorbs among the absorption spectrum of a red fluorescent substance, an emission spectrum, the spectrum of sunlight, and the spectrum of sunlight. It is a graph which shows the main transmissive wavelength range of a color filter. It is a plane schematic diagram which shows an example of the electronic device to which the fluorescent substance substrate or light-emitting device of this invention is applied. It is a perspective view which shows an example of the illuminating device to which the phosphor substrate or light-emitting device of this invention is applied. It is a figure which shows an example of the light emission spectrum of a fluorescent substance layer, and the transmittance | permeability of an intermediate | middle layer. It is a conceptual diagram of light reflection and transmission at the interface between the phosphor layer and the intermediate layer. It is a figure which shows the reflectance incident angle dependence in the interface of a fluorescent substance layer and an intermediate | middle layer in case the refractive index n1 = 1.5 of a fluorescent substance layer and the refractive index n2 = 1.6 of an intermediate | middle layer. The refractive index difference Δn of the reflectance at the interface between the phosphor layer and the intermediate layer when the refractive index of the phosphor layer is n1 = 1.5 and the incident angle θ = 10 ° (refractive index of phosphor layer n1− It is a figure which shows refractive index n2) dependence.

  Hereinafter, a phosphor substrate, a light emitting device, a display device, a lighting device, and a solar cell module according to the present invention will be described with reference to the drawings. The following embodiments are specifically described for better understanding of the gist of the invention, and do not limit the present invention unless otherwise specified. In addition, in the drawings used in the following description, in order to make the features of the present invention easier to understand, there is a case where a main part is shown in an enlarged manner for the sake of convenience. Not necessarily.

[First Embodiment]
The first embodiment of the present invention will be described below.
FIG. 1 is a schematic cross-sectional view of the phosphor substrate 100 of the first embodiment.

  The phosphor substrate 100 according to the present embodiment includes a light transmissive substrate 101, a light transmissive intermediate layer 107 formed on one surface 101 a of the substrate 101, and a phosphor layer 102 formed on the intermediate layer 107. And a light-scattering partition wall 111 standing on the one surface 101a of the substrate 101 so as to surround the side surface of the intermediate layer 107.

  In the present specification, “light-transmitting” refers to a property of transmitting at least light having a main emission wavelength of the phosphor layer. Further, “light scattering property” refers to a property of scattering at least light having a main emission wavelength of the phosphor layer.

  In the phosphor substrate 100, the side opposite to the surface facing the substrate 101 of the phosphor layer 102 is an excitation light incident surface Ef on which the excitation light FL that excites the phosphor layer 102 is incident. A band pass filter layer 105 is preferably formed on the excitation light incident surface Ef of the phosphor layer 102. The band pass filter layer 105 is a wavelength selection layer that transmits the excitation light FL and reflects the fluorescence generated in the phosphor layer 102 by the excitation light FL.

  The excitation light FL is emitted from an excitation light source (not shown) such as a blue LED. When the excitation light FL enters the phosphor layer 102 from the excitation light incident surface Ef, the phosphor layer 102 is excited and emits light. As the excitation light FL, for example, light of 400 nm or longer on the longer wavelength side than the near ultraviolet region is used. The phosphor layer 102 is excited by excitation light and emits fluorescence.

  The phosphor layer 102 includes one or more types of phosphors 103. The phosphor layer 102 may further include a light transmissive binder resin 104. The phosphor 103 may be either an organic phosphor or an inorganic phosphor. The phosphor 103 may be dissolved in a light transmissive binder resin 104 to form the phosphor layer 102 as a uniform film. In this case, the binder resin 104 and the phosphor 103 do not have an interface and cannot be distinguished. Therefore, interface reflection at the interface between the phosphor 103 and the binder resin 104 is suppressed, and light extraction efficiency is improved. The phosphor 103 may be formed into a spherical or indeterminate granular material regardless of the organic phosphor or the inorganic phosphor and dispersed in the binder resin 104. In this case, the respective phosphors 103 may have different shapes or the same shape. Further, the respective phosphors 103 may have different dimensions or the same dimensions.

  An intermediate layer 107 is formed between the phosphor layer 102 and the substrate 101. For example, the phosphor layer 102 is formed so as to overlap the intermediate layer 107. The intermediate layer 107 and the phosphor layer 102 are partitioned for each predetermined region by, for example, a partition wall 111 that rises from one surface 101a of the substrate 101 and surrounds the side surfaces along the thickness direction of each of the intermediate layer 107 and the phosphor layer 102. Yes. A region (side surface 111a) facing at least the intermediate layer 107 and the phosphor layer 102 of the partition wall 111 has light scattering properties.

  By separating the substrate 101 and the phosphor layer 102 by the intermediate layer 107, the incident angle range of the direct light directly incident on the substrate 101 from the phosphor layer 102 is limited. Since the light emitted from the phosphor layer 102 in the wide-angle direction does not directly enter the substrate 101, the light confined inside the substrate 101 by total reflection is reduced.

  The surface 107a of the intermediate layer 107 facing the substrate 101 is an interface between the substrate 101 and the intermediate layer 107, and the phosphor layer 102 at a position facing the center of the interface 107a when viewed from the normal direction of the substrate 101 is the phosphor layer 102. In the phosphor substrate 100 of the present embodiment, at least a part of the light having the emission main wavelength of the phosphor layer 102 emitted from the center portion of the phosphor layer 102 toward the outer edge portion of the interface 107a. Light reaches the substrate 101 without being scattered by the partition wall 111, and is an interface between the substrate 101 and the air layer at an angle smaller than the critical angle determined by the refractive index difference between the substrate 101 and the air layer outside the substrate 101. Is incident on.

  Here, “the surface 107a of the intermediate layer 107 facing the substrate 101 is the interface between the substrate 101 and the intermediate layer 107” means that the surface 107a of the intermediate layer 107 on the substrate 101 side is the interface between the substrate 101 and the intermediate layer 107. Is defined as The intermediate layer 107 is not necessarily in contact with the substrate 101, and the case where the intermediate layer 107 and the substrate 101 are separated via another member such as the color filter 113 is also included in the configuration of this embodiment.

  The “outer edge portion of the interface 107a” is a position where direct light from the phosphor layer 102 toward the substrate 101 passes through the interface 107a and is as close as possible to the outer edge portion of the interface 107a as long as it is not blocked by the partition wall 111. means. Direct light refers to light that is directly scattered on the substrate 101 from the phosphor layer 102 without being scattered by the barrier ribs 111. When the light shielding layer 112 is formed at the interface between the partition wall 111 and the substrate 101, the partition wall 111 and the light shielding layer 112 shield the direct light from the phosphor layer 102 toward the substrate 101 through the interface 107a. A position as close as possible to the outer edge of the interface 107a is defined as the outer edge of the interface 107a.

  A color filter 113 may be formed between the intermediate layer 107 and the substrate 101. For example, the intermediate layer 107 is formed so as to overlap the color filter 113. The color filter 113 is a filter layer that transmits light in the emission wavelength region of the phosphor layer 102. For example, the color filter 113 is formed between the intermediate layer 107 and the substrate 101, but may be formed between the phosphor layer 102 and the intermediate layer 107.

  A known color filter can be used as the color filter 113. By providing the color filter 113, the color purity of light emitted from the phosphor substrate 100 can be increased. Therefore, when the phosphor substrate 100 is applied to a display device, the display color reproduction range can be expanded.

  The color filter 113 is formed in an area partitioned by the light shielding layer 112, for example. The light blocking layer 112 has a function of blocking light transmission. The light shielding layer 112 is formed of, for example, a metal such as Cr (chromium) or a Cr / Cr oxide multilayer film, or a photoresist in which carbon particles are dispersed in a photosensitive resin.

  Hereinafter, although the constituent material examples of each element constituting the phosphor substrate 100 of the present embodiment are listed, the present invention is not limited to these.

  Since the substrate 101 needs to extract the fluorescence emitted from the phosphor layer 102 from the fluorescence emission surface Ff of the substrate 101, the substrate 101 needs to have light transmittance with respect to the fluorescence from the phosphor layer 102. For example, an inorganic material substrate made of glass, quartz or the like, a plastic substrate made of polyethylene terephthalate, polycarbazole, polyimide, or the like can be given. The total light transmittance of the substrate 101 is preferably 90% or more as defined in JIS K7361-1. When the total light transmittance is 90% or more, sufficient transparency can be obtained.

  The intermediate layer 107 is made of a light-transmitting material having a refractive index close to the refractive index of the substrate 101 and the phosphor layer 102 so that the fluorescence emitted from the phosphor layer 102 is efficiently incident on the substrate 101. It is preferable. This is because if there is a significant difference between the refractive indexes of the two, an interface reflection described by the Fresnel formula occurs at the interface between the phosphor layer 102 and the intermediate layer 107. The greater the difference in refractive index, the greater the amount of reflection, so it is desirable that the refractive indices of the two be as close as possible.

  Of the fluorescence emitted from the phosphor layer 102, the component reflected at the interface between the phosphor layer 102 and the intermediate layer 107 is reflected by the partition wall 111 and the band pass filter layer 105, and the phosphor layer 102 and the intermediate layer 107. It is incident again on the interface. The component reflected at the interface between the phosphor layer 102 and the intermediate layer 107 is somewhat attenuated when reflected by the partition wall 111 and the bandpass filter layer 105. In addition, when the phosphor layer 102 has absorption with respect to the fluorescence wavelength, the fluorescence is somewhat attenuated while being guided through the phosphor layer 102. Therefore, it is desirable that the amount of reflection at the interface between the phosphor layer 102 and the intermediate layer 107 is small.

  For example, the difference in the refractive index between the phosphor layer 102 and the intermediate layer 107 (the refractive index at the emission main wavelength of the phosphor layer 102) is preferably 0.3 or less. By providing the intermediate layer 107, an effect of improving the emission efficiency of the phosphor layer 102 by several percent or more is obtained. If the difference in refractive index between the intermediate layer 107 and the phosphor layer 102 is within 0.3, generally the reflectance at the interface between the two is equivalent to the improvement in extraction efficiency by providing the intermediate layer 107. The effect is not offset. More desirably, the difference in refractive index between the intermediate layer 107 and the phosphor layer 102 is 0.1 or less. When the difference in refractive index between the intermediate layer 107 and the phosphor layer 102 is 0.1 or less, the reflectance at the interface between them can be approximated to “almost zero”, and the interface reflection can be almost ignored.

  Most preferably, the phosphor layer 102 and the intermediate layer 107 are made of the same material and have the same refractive index. That is, the binder resin 104 and the intermediate layer 107 of the phosphor layer 102 are preferably made of the same material.

  FIG. 32 shows a conceptual diagram of light reflection / transmission at the interface between the phosphor layer 102 and the intermediate layer 107. Fluorescence generated in the phosphor layer 102 is reflected and transmitted at the interface when entering the phosphor layer 102-intermediate layer 107 interface.

  For example, FIG. 33 shows the reflectance incident angle dependency at the interface between the phosphor layer 102 and the intermediate layer 107 when the refractive index n1 of the phosphor layer 102 is 1.5 and the refractive index n2 of the intermediate layer 107 is 1.6. Shown in Although the reflectance at the interface between the phosphor layer 102 and the intermediate layer 107 has an incident angle dependency, the reflectance can be regarded as substantially constant until the incident angle = 60 °.

  FIG. 34 shows the refractive index difference Δn of the reflectance at the interface between the phosphor layer 102 and the intermediate layer 107 when the refractive index n1 of the phosphor layer 102 is 1.5 and the incident angle θ is 10 ° (of the phosphor layer 102). Refractive index n1—The refractive index n2) dependence of the intermediate layer 107 is shown. FIG. 34 shows that when the refractive index difference is within 0.3, the reflectance is 1% or less, and when the refractive index difference is within 0.1, the reflectance is almost zero.

  When there is a difference in the refractive index between the phosphor layer 102 and the intermediate layer 107, the refractive index of the phosphor layer 102 is preferably smaller than the refractive index of the intermediate layer 107. When the refractive index of the phosphor layer 102 is smaller than the refractive index of the intermediate layer 107, the penetration angle from the phosphor layer 102 to the intermediate layer 107 is increased by Snell's law. Therefore, light can be easily incident on the interface between the intermediate layer 107 and the substrate 101 at an angle smaller than the critical angle, and light can be easily extracted from the substrate 101 to the air side.

  As the material of the intermediate layer 107, either an organic material such as an acrylic resin or an inorganic material such as silicon oxide can be used. However, when an intermediate layer 107 having a high aspect ratio is used, an acrylic resin or the like is used. It is preferable to use an organic material and form it using a technique such as coating. The total light transmittance of the intermediate layer 107 is preferably 90% or more in accordance with JIS K7361-1. When the total light transmittance is 90% or more, sufficient transparency can be obtained.

  In the present embodiment, the intermediate layer 107 is made of a colorless and transparent resin, but the intermediate layer 107 does not necessarily need to be colorless and transparent. For example, the intermediate layer 107 may be made of a material in which the average transmittance in the emission wavelength region of the phosphor layer 102 is higher than the average transmittance in a wavelength region other than the emission wavelength region of the phosphor layer 102. As such a material, the same material as the color filter 113 can be used.

  The “average transmittance in the emission wavelength region of the phosphor layer” refers to the average transmittance in the wavelength region of the emission main wavelength (emission peak wavelength) ± 50 nm of the phosphor layer. The “average transmittance in a wavelength range other than the emission wavelength range of the phosphor layer” is the emission wavelength range of the phosphor layer (the emission main wavelength of the phosphor layer) in the visible wavelength range (a wavelength range of 380 nm to 780 nm). Mean transmittance in a wavelength range other than (± 50 nm wavelength range). The “average transmittance” is calculated as a value obtained by dividing the integral value of the transmittance in the target wavelength region by the size of the wavelength region.

  As an example, the “average transmittance in the emission wavelength region of the phosphor layer” will be specifically described using the actual emission spectrum of the phosphor layer and the transmittance of the intermediate layer. FIG. 31 shows the emission spectrum of the phosphor layer and the transmittance of the intermediate layer.

  The emission peak wavelength of ± 50 nm is defined as the “emission wavelength region of the phosphor layer”. The critical significance of ± 50 nm comes from the fact that the full width at half maximum is about ± 50 nm or less in the emission spectra of many phosphors. In the case of FIG. 31, 3- (2′-benzothiazolyl) -7-diethylaminocoumarin (coumarin 6) is used as the material of the phosphor layer. Since the emission peak wavelength is 515 nm, the “emission wavelength region of the phosphor layer” is 465 to 565 nm, and the average transmittance is 63%. The “wavelength region other than the emission wavelength region of the phosphor layer” is 380 to 465 nm and 565 to 780 nm, and the average transmittance is 8%. Therefore, the intermediate layer in FIG. 31 is made of a material whose average transmittance in the emission wavelength region of the phosphor layer is higher than the average transmittance in a wavelength region other than the emission wavelength region of the phosphor layer.

  The comparison of average transmittance can be similarly defined by measuring and comparing relative transmittance, not absolute transmittance. That is, the relative transmission spectrum of the material may be measured. The relative transmission spectrum can be measured using a small piece cut out from the intermediate layer. The small piece of the intermediate layer is placed in the integrating sphere of the total luminous flux measurement system (integrated hemisphere QE-1100 manufactured by Otsuka Electronics Co., Ltd.), and the incident light intensity spectrum I0 when the small piece is not placed and the attenuated incident light intensity when the small piece is placed. The spectrum I1 is measured. This attenuation originates from the fact that light is absorbed by the intermediate layer when the incident light travels through the intermediate layer by the distance d1. Therefore, the transmittance T1 can be defined by Expression (1) and Expression (2) using I1 and I0. α is the absorption coefficient of the intermediate layer.

  Since d1 in the formula (2) is different from the film thickness d2 of the intermediate layer in the actual device, the transmittance T1 is different in absolute value from the transmittance T2 of the intermediate layer in the actual device (formula (3)). .

  However, since only the absorption coefficient α is dependent on the wavelength among the parameters in the equation (2), the normalized transmission spectra of the equations (2) and (3) are equivalent. Therefore, the relative transmission spectrum T1 of the material may be measured using the above method. In this embodiment, when comparing the “average transmittance in the emission wavelength region of the phosphor layer” with the “average transmittance in a wavelength region other than the emission wavelength region of the phosphor layer”, the equation (2) α is obtained, and the relative transmittance T2 is obtained by the equation (3) using the α. Then, the integral average of the relative transmittance within the target wavelength range is calculated as the average transmittance, and in the comparison of the average transmittance, the “average transmittance in the emission wavelength range of the phosphor layer” and “emission of the phosphor layer” Comparison with “average transmittance in a wavelength range other than the wavelength range” is performed.

  The partition 111 is made of, for example, a material containing resin and light scattering particles. For example, it is preferable that light scattering particles having a higher refractive index than the resin are dispersed in a resin having a low refractive index. Further, in order for blue light to be effectively scattered by the light-scattering partition walls, the particle size of the light-scattering particles needs to be in the Mie scattering region. About -500 nm is preferable.

  The resin material constituting the partition wall 111 is preferably a light transmissive resin. Specific examples of the resin material include acrylic resin (refractive index: 1.49), melamine resin (refractive index: 1.57), nylon (refractive index: 1.53), polystyrene (refractive index: 1.60), Melamine beads (refractive index: 1.57), polycarbonate (refractive index: 1.57), polyvinyl chloride (refractive index: 1.60), polyvinylidene chloride (refractive index: 1.61), polyvinyl acetate (refractive) Ratio: 1.46), polyethylene (refractive index: 1.53), polymethyl methacrylate (refractive index: 1.49), poly MBS (refractive index: 1.54), medium density polyethylene (refractive index: 1. 53), high density polyethylene (refractive index: 1.54), tetrafluoroethylene (refractive index: 1.35), poly (trifluoroethylene chloride) (refractive index: 1.42), polytetrafluoroethylene (refractive index: 1.3 ), And the like.

  When an inorganic material is used as the light-scattering particles constituting the partition wall 111, for example, oxidation of at least one metal selected from the group consisting of silicon, titanium, zirconium, aluminum, indium, zinc, tin, and antimony Examples thereof include particles mainly composed of an object.

When particles (inorganic particles) composed of an inorganic material are used for the partition wall 111, for example, silica beads (refractive index: 1.44), alumina beads (refractive index: 1.63), titanium oxide beads (refractive index). Anatase type: 2.50, rutile type: 2.70), zirconia oxide beads (refractive index: 2.05), zinc oxide beads (refractive index: 2.00), barium titanate (BaTiO ₃ ) (refractive index: 2.4).

  When particles (organic particles) made of an organic material are used for the partition 111, for example, polymethylmethacrylate beads (refractive index: 1.49), acrylic beads (refractive index: 1.50), acrylic-styrene Polymer beads (refractive index: 1.54), melamine beads (refractive index: 1.57), high refractive index melamine beads (refractive index: 1.65), polycarbonate beads (refractive index: 1.57), styrene beads (Refractive index: 1.60), crosslinked polystyrene beads (refractive index: 1.61), polyvinyl chloride beads (refractive index: 1.60), benzoguanamine-melamine formaldehyde beads (refractive index: 1.68), silicone beads (Refractive index: 1.50).

  By selecting an alkali-soluble resin as a constituent resin of the material of the partition 111 and adding a photopolymerizable monomer, a photopolymerization initiator, and a solvent, the partition material can be made into a photoresist, and patterned by photolithography. 111 can be formed.

  The vertical and horizontal sizes of the openings defined by the partition walls 111 are, for example, about 20 μm × 20 μm to about 500 μm × 500 μm. The opening of the partition 111 refers to a region of one partition of the partition 111 that surrounds one intermediate layer 107. In the case of the present embodiment, since the barrier ribs 111 are erected on the substrate 101 so as to surround the side surfaces of the intermediate layer 107 and the phosphor layer 102, the barrier ribs 111 surrounding the one intermediate layer 107 and the single phosphor layer 102. A region for one section is an opening of the partition wall 111. The partition 111 preferably has a reflectance of 80% or more in the CIE 1976 L * a * b display system.

  In the case where the phosphor substrate 100 is applied to a display device, for the purpose of improving the contrast, the light scattering barrier 111 has a lighter black color than the light scattering barrier 111 of about 0.01 μm to 3 μm on the light extraction direction side. A partition layer may be inserted. For example, the black partition layer is disposed between the bottom of each partition 111 and the substrate 101. When the light shielding layer 112 for partitioning the color filter 113 is formed at this position, the light shielding layer 112 can also be used as a black partition layer.

  Further, in order to prevent excitation light designed to enter a certain pixel from leaking to adjacent pixels and causing color mixing, a light-scattering partition wall 111 is formed for the purpose of absorbing light entering the adjacent pixels. A thin black barrier rib layer may be inserted on the side opposite to the light extraction direction in comparison with the light-scattering barrier rib 111 having a thickness of about 0.01 μm to 3 μm.

  In the case where the intermediate layer 107 and the phosphor layer 102 are patterned by a dispenser method, an ink jet method, or the like, in order to prevent the solution from overflowing from the partition wall 111 and mixing colors between adjacent pixels, the partition wall 111 is provided with liquid repellency. Is preferred. Examples of a method for imparting liquid repellency to the partition wall 111 include the following methods.

(1) Fluorine plasma treatment For example, as disclosed in Japanese Patent Application Laid-Open No. 2000-76979, a plasma treatment is performed on a substrate on which a partition wall is formed under a condition where the introduced gas is a fluorine-based gas, thereby repelling the partition wall. Liquidity can be imparted.

(2) Addition of fluorinated surface modifier A liquid repellency can be imparted to the partition walls by adding a fluorinated surface modifier to the light scattering partition material. As the fluorine-based surface modifier, for example, a UV curable surface modifier Defenser (manufactured by DIC Corporation), Mega Fuck, etc. can be used.

  The shape of the partition wall 111 is formed in a tapered shape such that the opening of the partition wall 111 is wider on the incident side than the exit side of the excitation light so that the excitation light does not enter the adjacent pixel of the pixel that should be incident. It may be. Further, in order to sufficiently improve the adhesion between the substrate 101 and the partition wall 111, the ratio of the height of the partition wall 111 to the lateral width of the partition wall 111 (aspect ratio) may be 1 or more.

  The band pass filter layer 105 preferably has a characteristic of transmitting only the wavelength of the excitation light. For example, when the wavelength of the excitation light is blue (wavelength 450 nm), the bandpass filter layer 105 transmits light in the blue region (light in the wavelength range of 435 to 480 nm) and light from green to the near infrared region. It has a function of reflecting (light outside the wavelength range of the blue region). The bandpass filter layer 105 is made of, for example, a thin film such as gold or silver, or a dielectric multilayer film.

  As the phosphor material constituting the phosphor 103, in the case of an organic phosphor material, as a blue fluorescent dye, for example, stilbenzene dye: 1,4-bis (2-methylstyryl) benzene, trans-4,4 '-Diphenylstilbenzene, coumarin dye: 7-hydroxy-4-methylcoumarin, 2,3,6,7-tetrahydro-11-oxo-1H, 5H, 11H- [1] benzopyrano [6,7,8- ij] ethyl quinolidine-10-carboxylate (coumarin 314), 10-acetyl-2,3,6,7-tetrahydro-1H, 5H, 11H- [1] benzopyrano [6,7,8-ij] quinolidine-11 -On (coumarin 334), anthracene dyes: 9,10 bis (phenylethynyl) anthracene, perylene and the like.

  In addition, as a green fluorescent dye of an organic phosphor material, for example, a coumarin dye: 2,3,5,6-1H, 4H-tetrahydro-8-trifluoromethylquinolidine (9,9a, 1-gh) coumarin (Coumarin 153), 3- (2'-benzothiazolyl) -7-diethylaminocoumarin (coumarin 6), 3- (2'-benzimidazolyl) -7-N, N-diethylaminocoumarin (coumarin 7), 10- (benzothiazole -2-yl) -2,3,6,7-tetrahydro-1H, 5H, 11H- [1] benzopyrano [6,7,8-ij] quinolizin-11-one (coumarin 545), coumarin 545T, coumarin 545P , Naphthalimide dyes: basic yellow 51, solvent yellow 11, solvent yellow 98, solvent yellow 116 Solvent Yellow 43, Solvent Yellow 44, Perylene dyes: Lumogen Yellow, Lumogen Green, Solvent Green 5, fluorescein dye, azo dye, phthalocyanine dye, anthraquinone dye, quinacridone dye, isoindolinone dye, Examples include thioindigo dyes and dioxazine dyes.

  Examples of red fluorescent dyes for organic phosphor materials include cyanine dyes: 4-dicyanomethylene-2-methyl-6- (p-dimethylaminostyryl) -4H-pyran (DCM), DCM-2. DCJTB, pyridine dye: 1-ethyl-2- [4- (p-dimethylaminophenyl) -1,3-butadienyl] -pyridinium-perchlorate (pyridine 1), and xanthene dye: rhodamine B, rhodamine 6G , Rhodamine 3B, rhodamine 101, rhodamine 110, basic violet 11, sulforhodamine 101, basic violet 11, basic red 2, perylene dye: lumogen orange, lumogen pink, rumogen red, solvent orange 55, oxazine dye, chrysene dye, Thiofurabi Dye, pyrene dye, anthracene dye, acridone dye, acridine dye, fluorene dye, terphenyl dye, ethene dye, butadiene dye, hexatriene dye, oxazole dye, coumarin dye, stilbene And dyes such as di- and triphenylmethane dyes, thiazole dyes, thiazine dyes, naphthalimide dyes and anthraquinone dyes.

  When an organic phosphor material is used as each color phosphor, it is desirable to use a dye that is not easily degraded by blue light, ultraviolet light, or external light of the backlight. In this respect, it is particularly preferable to use a perylene dye having excellent light resistance and a high quantum yield.

In the case of an inorganic phosphor material, as a blue phosphor, Sr ₂ P ₂ O ₇ : Sn ₄ +, Sr ₄ Al ₁₄ O ₂₅ : Eu ²⁺ , BaMgAl ₁₀ O ₁₇ : Eu ²⁺ , SrGa ₂ S ₄ : Ce ³⁺ , CaGa ₂ S ₄ : Ce ³⁺ , (Ba, Sr) (Mg, Mn) Al ₁₀ O ₁₇ : Eu ²⁺ , (Sr, Ca, Ba ₂ , 0 Mg) ₁₀ (PO ₄ ) _{6 Cl 2} : Eu ²⁺ , BaAl ₂ SiO ₈ : Eu ²⁺ , Sr ₂ P ₂ O ₇ : Eu ²⁺ , Sr ₅ (PO ₄ ) ₃ Cl: Eu ²⁺ , (Sr, Ca, Ba) ₅ (PO ₄ ) ₃ Cl: Eu ²⁺ , BaMg ₂ Al ^{_{16 O 27: Eu 2+, (}} Ba, Ca) 5 (PO 4) 3 Cl: Eu 2+, Ba 3 MgSi 2 O 8: Eu 2+, Sr 3 MgSi 2 O 8: Eu 2+ , etc. And the like

In addition, as the green phosphor of the inorganic phosphor material, (BaMg) Al ₁₆ O ₂₇ : Eu ²⁺ , Mn ²⁺ , Sr ₄ Al ₁₄ O ₂₅ : Eu ²⁺ , (SrBa) Al ₁₂ Si ₂ O ₈ : Eu ²⁺ , (BaMg) ₂ SiO ₄ : Eu ²⁺ , Y ₂ SiO ₅ : Ce ³⁺ , Tb ³⁺ , Sr ₂ P ₂ O ⁷ -Sr ₂ B ₂ O ₅ : Eu ²⁺ , (BaCaMg) ₅ (PO ₄ ) ₃ Cl: Eu ²⁺ , Sr ₂ Si ₃ O ₈ -2SrCl ₂ : Eu ²⁺ , Zr ₂ SiO ₄ , MgAl ₁₁ O ₁₉ : Ce ³⁺ , Tb ³⁺ , Ba ₂ SiO ₄ : Eu ²⁺ , Sr ₂ SiO ₄ : Eu ²⁺ , (BaS ^{_{) SiO 4: Eu 2+, (}} Si, Al) 6 (O, N) 8: Eu 2+, Ca 3 (Sc, Mg) 2 Si 3 O 12: Ce 3+, SrSi _{(O, Cl) 2 N 2} : Eu 2+ and the like.

As red phosphors of inorganic phosphor materials, Y ₂ O ₂ S: Eu ³⁺ , YAlO ₃ : Eu ³⁺ , Ca ₂ Y ₂ (SiO ₄ ) ₆ : Eu ³⁺ , LiY ₉ (SiO ₄ ) ₆ O ₂ : Eu ³⁺ , YVO ₄ : Eu ³⁺ , CaS: Eu ³⁺ , Gd ₂ O ₃ : Eu ³⁺ , Gd ₂ O ₂ S: Eu ³⁺ , Y (P, V) O ₄ : Eu ³⁺ , Mg ₄ GeO ₅ . 5F: Mn ⁴⁺ , Mg ₄ GeO ₆ : Mn ⁴⁺ , K ₅ Eu _2.5 (WO ₄ ) _6.25 , Na ₅ Eu _2.5 (WO ₄ ) _6.25 , K ₅ Eu _2.5 (MoO _{4 6.25} , Na ₅ Eu _2.5 (MoO ₄ ) _6.25 , (Sr, Ca) AlSiN ₃ : Eu ²⁺ , CaAlSiN ₃ : Eu ²⁺ , SrSiN ₂ : Eu ²⁺ , SrAlSiN ₃ : Eu ²⁺ , Ca ₂ Si ₅ N ₈ : Eu ²⁺ , Sr ₂ Si ₅ N ₈ : Eu ²⁺ , Ba ₂ AlSi ₅ N ₈ : Eu ²⁺ , Sr ₂ Si ₃ O ₂ N ₄ : Eu ²⁺ , Sr ₂ Si ₃ Al ₂ O ₂ N ₆ : Eu ²⁺ , SrSc ₂ O ₄ : Eu ²⁺ , (Sr, Ba) ₃ SiO ₅ : Eu ²⁺ , Mg ₂ TiO ₄ : Mn ^{2+ and the} like.

  The inorganic phosphor material may be subjected to a surface modification treatment as necessary. The method may be a chemical treatment such as a silane coupling agent or a physical treatment by adding submicron order particles. And those using a combination thereof. In consideration of stability such as deterioration due to excitation light and deterioration due to light emission, it is generally preferable to use an inorganic material.

In the case of inorganic phosphors, these phosphors generally have a refractive index = 1.8 or higher. For example, the refractive index of YAG: Ce, TAG: Ce, Al ₂ O ₃ : Ce is about 1.8. In the case of organic phosphors, those having a high refractive index of about 1.7 or more are generally used. For example, the refractive index of C ₂₀ H ₁₈ N ₂ O ₂ S (coumarin 6) is about 1.69.

  The phosphor layer 102 can be patterned by a photolithography method using a photosensitive resin as a polymer resin. Here, as the photosensitive resin, a photosensitive resin (photocurable resist material) having a reactive vinyl group such as an acrylic acid resin, a methacrylic acid resin, a polyvinyl cinnamate resin, or a hard rubber resin is used. It is possible to use one kind or a mixture of several kinds.

  Also, wet process such as ink jet method, relief printing method, intaglio printing method, screen printing method, dispenser method, resistance heating vapor deposition method using shadow mask, electron beam (EB) vapor deposition method, molecular beam epitaxy (MBE) method, It is also possible to directly pattern the phosphor material by a known dry process such as a sputtering method or an organic vapor deposition (OVPD) method, or a laser transfer method.

  The binder resin material is preferably a light transmissive resin. Examples of the resin material include acrylic resin, melamine resin, polyester resin, polyurethane resin, alkyd resin, epoxy resin, butyral resin, polysilicone resin, polyamide resin, polyimide resin, melanin resin, phenol resin, polyvinyl alcohol, polyvinyl Hydrine, hydroxyethyl cellulose, carboxymethyl cellulose, aromatic sulfonamide resin, urea resin, benzoguanamine resin, triacetyl cellulose (TAC), polyethersulfone, polyetherketone, nylon, polystyrene, melamine beads, polycarbonate, polyvinyl chloride, Polyvinylidene chloride, polyvinyl acetate, polyethylene, polymethyl methacrylate, poly MBS, medium density polyethylene, high density polyethylene, tetrafluoroethylene Oroechiren, poly trifluorochloroethylene, polytetrafluoroethylene and the like.

  Hereinafter, the operation of the phosphor substrate of the present embodiment will be described with reference to FIG. 2 in comparison with the phosphor substrates of the comparative examples (Comparative Example 1 and Comparative Example 2).

FIG. 2A is a schematic cross-sectional view showing the operation of the phosphor substrate of Comparative Example 1.
FIG. 2B is a schematic cross-sectional view showing the operation of the phosphor substrate of Comparative Example 2.
FIG. 2C is a schematic cross-sectional view showing the operation of the phosphor substrate of the present embodiment.

  FIG. 2A: The phosphor substrate of Comparative Example 1 is obtained by forming a phosphor layer 202 on one surface of a light transmissive substrate 201. The phosphor layer 202 is obtained by dispersing an inorganic phosphor 203 in a binder resin 204. A wavelength selection layer 205 is formed on the phosphor layer 202 (on the opposite side of the substrate 201).

  FIG. 2B: The phosphor substrate of Comparative Example 2 is obtained by forming a phosphor layer 202 on one surface of a light transmissive substrate 201. The phosphor layer 202 is obtained by dissolving the organic phosphor 203 in the binder resin 204. A wavelength selection layer 205 is formed on the phosphor layer (on the opposite side of the substrate 201).

  FIG. 2C: The phosphor substrate of the present embodiment is obtained by forming the intermediate layer 107 on one surface of the light transmissive substrate 101 and forming the phosphor layer 102 on the intermediate layer 107. The phosphor layer 102 is obtained by dissolving the organic phosphor 103 in the binder resin 104. A wavelength selection layer 105 is formed on the phosphor layer 102 (on the opposite side of the substrate 101).

  In the phosphor substrate of Comparative Example 1 shown in FIG. 2A, the fluorescence 208a having an angle smaller than the critical angle determined by the difference in refractive index at the interface 201b between the substrate 201 and air (outside air) is extracted to the air side. It is. Even if the fluorescence has an angle larger than the critical angle, the one 208c scattered by the partition wall 211 changes the reflection angle, so that it enters the interface 201b again at an angle smaller than the critical angle and is taken out to the air side. . On the other hand, the light emission 209 having an angle larger than the critical angle determined by the refractive index difference is totally reflected and guided through the substrate 201, so that the light emission cannot be efficiently extracted outside the substrate 201.

  In the phosphor substrate of Comparative Example 2 shown in FIG. 2B, light emission 208a having an angle smaller than the critical angle determined by the difference in refractive index at the interface 201b between the substrate 201 and air (outside air) is extracted to the air side. It is. Even if the fluorescence has an angle larger than the critical angle, the one 208c scattered by the partition wall 211 changes the reflection angle, so that it enters the interface 201b again at an angle smaller than the critical angle and is taken out to the air side. . On the other hand, since the light emission 209 having an angle larger than the critical angle determined by the refractive index difference is totally reflected and guided through the substrate 201 and the phosphor layer 202, the light emission is efficiently performed in the same manner as in Comparative Example 1. Can not be taken out of the outside.

  In the phosphor substrate of this embodiment shown in FIG. 2C, light emitted from the phosphor 103 enters the substrate 101 through the intermediate layer 107. Since the phosphor layer 102 and the substrate 101 are separated from each other by the intermediate layer 107, the angle of the light 108a that directly enters the substrate 101 without entering the partition wall 111 from the phosphor layer 102 is limited to a narrow angle range. Therefore, the ratio of light confined inside the substrate 101 by total reflection is smaller than when the phosphor layer is provided in contact with or close to the substrate.

  A part of the light 108c emitted from the lower surface of the phosphor layer 102 toward the substrate 101 at an angle equal to or larger than the critical angle is scattered by the partition wall 111, and the reflection angle is changed. It enters the interface 101b with the layer (outside air) and is taken out to the air layer side. The light 109 incident on the substrate 101 at an angle greater than the critical angle even though scattered by the barrier ribs 111 is lost while being totally reflected from the inside of the substrate 101, but is greater than the critical angle from the lower surface of the phosphor layer. Compared with the configurations of Comparative Example 1 and Comparative Example 2 in which almost all light emitted to the substrate side at an angle is lost, the light loss is small.

  Note that when the thickness of the intermediate layer 107 is increased and the distance between the phosphor layer 102 and the substrate 101 is increased, the number of times of scattering by the barrier ribs 111 increases. Therefore, if the loss of light at the time of scattering is not zero, the light extraction efficiency is likely to be small. However, if the reflectance of the partition wall 111 is increased, such light loss can be sufficiently reduced, so that more light emission is generated in the phosphor layer 102 than in the configurations of Comparative Example 1 and Comparative Example 2. The light can be emitted toward the outside of 101. Therefore, it is possible to increase the fluorescence emission efficiency of the phosphor substrate.

  By the way, in the phosphor substrate 100 of the present embodiment, the light extraction efficiency varies depending on the aspect ratio of the intermediate layer 107 and the reflectance of the partition walls 111. This is because when the aspect ratio of the intermediate layer 107 is increased, the number of times of scattering by the partition 111 increases, and when the reflectance of the partition 111 is small, a light loss occurs according to the number of scattering.

  Therefore, in the present embodiment, a suitable range of the aspect ratio of the intermediate layer and the reflectance of the partition wall 111 is determined by the following method. Hereinafter, a method for determining a suitable range of the aspect ratio of the intermediate layer and the reflectance of the partition 111 will be described with reference to FIGS.

  FIG. 3 is a diagram showing the incident angle and the outgoing angle of light at each interface of the intermediate layer, the substrate, and the air.

As shown in FIG. 3, when Snell's law is used, the incident angle θ ₂ and the outgoing angle θ _{3 at} the interface between the intermediate layer and the substrate, and the incident angle θ ₃ and the outgoing angle θ _{4 at} the interface between the substrate and the air The following relational expression holds between:

Here, n ₂ is the refractive index of the intermediate layer, n ₃ is the refractive index of the substrate, and n ₄ is the refractive index of air. The measurement wavelength of the refractive index is the dominant wavelength of fluorescence emitted from the phosphor layer (for example, 550 nm).

When n ₄ = 1.0 in equation (5), the critical angle θ ₃ at which θ ₄ = 90 ° (total reflection condition) is obtained by the following equation (6).

  When formula (4) is inserted into formula (6), the following formula (7) is obtained.

Therefore, when the incident angle θ ₂ is larger than the angle calculated by the equation (7) (hereinafter sometimes referred to as the critical angle θ ₂ ), total reflection occurs at the interface between the substrate and air, and the light is air Not taken out to the side.

FIG. 4 is a diagram showing a correlation between the refractive index n ₂ and the critical angle θ ₂ of the intermediate layer obtained by the equation (7).

As shown in FIG. 4, the critical angle θ ₂ decreases as the refractive index n ₂ of the intermediate layer increases. In the case of this embodiment, the intermediate layer is made of a transparent resin or inorganic layer, and the refractive index of these materials is usually in the range of 1.3 to 1.7 (the range indicated by the arrow in FIG. 4). Therefore, the critical angle θ ₂ is in the range of 36 ° to 50 °. For example, when n ₂ = 1.5, the critical angle θ ₂ = 42 °, and when n ₂ = 1.56, the critical angle θ ₂ = 40 °.

FIG. 5 is a schematic cross-sectional view showing a light propagation state in a phosphor substrate that does not include a partition wall.
FIG. 6 is a schematic cross-sectional view showing a light propagation state in a phosphor substrate provided with a partition wall.

For example, when n ₂ = 1.56, as shown in FIG. 5, light having an angle larger than the critical angle θ ₂ = 40 ° is totally reflected. As shown in FIG. 6, when a light-scattering partition wall is installed so that light having an angle larger than the critical angle θ ₂ = 40 ° radiated from the center of the phosphor layer is reflected, the light is guided through the substrate in FIG. Some of the components that have been removed are taken out to the air side.

  Here, an optimum aspect ratio of the intermediate layer is considered from the viewpoint of light extraction efficiency from the phosphor substrate.

FIG. 7A is a perspective view showing a phosphor layer and an intermediate layer in a region (hereinafter, also referred to as an opening of the partition wall) for one partition partitioned by the partition wall.
FIG. 7B is a schematic cross-sectional view in the plane A of FIG. 7A (a plane parallel to the short side direction of the opening of the partition wall).
In FIG. 7, illustration of the color filter and the light shielding layer shown in FIG. 1 is omitted for the sake of convenience.

  In FIG. 7, as an example, the size of the opening of the partition is 100 μm × 300 μm, and the short side size (100 μm) of the opening of the partition is defined as the opening diameter. The reason for discussing the extraction efficiency in a cross section parallel to the short side direction is that the area of the side wall of the partition parallel to the long side direction is larger than the area of the side of the partition parallel to the short side direction, which also contributes to the extraction efficiency. Because it is big.

  The size of the opening of the partition wall is defined as the size of the interface between the intermediate layer and the substrate. In the following description, terms such as “interface between the intermediate layer and the substrate”, “outer edge of the interface”, and “central part of the phosphor layer” are used, and these definitions are as described above.

In the following description, the critical angle determined by the refractive index n ₂ of the intermediate layer is θ ₂ , the height of the intermediate layer is h, and the shortest length from the center of the interface between the intermediate layer and the substrate to the outer edge of the interface is w. / 2, A is the aspect ratio h / w of the intermediate layer, P is the total light emission amount of the phosphor layer, E is the amount of light transmitted through the substrate and extracted outside the substrate, and the extraction efficiency E / P is defined as η To do.

  The “total emission amount of the phosphor layer” is the total amount of light in all directions of the phosphor layer that emits fluorescence by excitation light having an arbitrary excitation wavelength (all wavelengths, light from portions other than the central portion of the phosphor layer). Luminescence is also included). “The amount of light transmitted through the substrate and extracted outside the substrate” is the total amount of light emitted from the side of the substrate facing the phosphor layer and the interface of the substrate (of the total emission amount of the phosphor layer) ( All wavelength range).

  The “total light emission amount of the phosphor layer” is measured by placing the phosphor substrate in an integrating sphere of a total luminous flux measurement system (integrated hemisphere QE-1100 manufactured by Otsuka Electronics Co., Ltd.) and measuring the total light emission amount. “The amount of light transmitted through the substrate and extracted outside the substrate” refers to the direction in which the light emitted through the substrate enters the integrating sphere through the same size window as the phosphor substrate provided in the integrating sphere QE-1100. Thus, the measurement is performed by attaching a phosphor substrate and measuring the amount of light emitted through the substrate.

  In order for the light emitted from the central portion of the phosphor layer to reach the substrate directly without being scattered by the barrier ribs and to be extracted outside the substrate without being confined inside the substrate by total reflection, The aspect ratio A needs to be set to a value equal to or larger than the value calculated by the following formula (8).

Between tanθ ₂ and sinθ ₂ , there is a relationship represented by the following formula (9) derived from Pythagorean theorem. Therefore, when using the equations (7) to (9), the following equation (10) is established between the aspect ratio A of the intermediate layer calculated by the equation (8) and the refractive index n ₂ of the intermediate layer. There is a serious relationship.

FIG. 8 is a diagram showing a correlation between the refractive index n ₂ of the intermediate layer and the aspect ratio A (= h / w) of the intermediate layer obtained by Expression (10).

When the aspect ratio A of the intermediate layer is equal to or greater than the value calculated by the equation (10), the light emitted from the central portion of the phosphor layer at an angle smaller than the critical angle θ ₂ is It reaches the substrate directly without being scattered by the partition walls. Therefore, almost all of this light is extracted outside the substrate without being confined in the substrate.

Light emitted from the central portion of the phosphor layer at an angle larger than the critical angle θ ₂ is incident on the side surface of the partition wall and scattered, and a part of the light enters the substrate at an angle smaller than the critical angle θ ₂ . When the partition is not formed, all such light is confined inside the substrate by total reflection. However, when the partition is formed, a part of such light is scattered by the partition. To be taken out of the substrate.

  Hereinafter, the effect when the aspect ratio A of the intermediate layer is optimized will be described with reference to FIG.

FIG. 9A is a schematic cross-sectional view of the phosphor substrate of Comparative Example 3.
FIG. 9B is a schematic cross-sectional view of the phosphor substrate of Comparative Example 4.
FIG. 9C is a schematic cross-sectional view of the phosphor substrate of Example 1.

FIG. 9A: The phosphor substrate of Comparative Example 3 has a phosphor layer formed on one surface of a glass substrate. The side surface of the partition wall facing the intermediate layer is a scattering reflection surface that scatters light.
FIG. 9B: The phosphor substrate of Comparative Example 4 is obtained by forming an intermediate layer on one surface of a glass substrate and forming a phosphor layer on the intermediate layer. The side surface of the partition wall facing the intermediate layer is a mirror reflection surface that regularly reflects light.
FIG. 9C: The phosphor substrate of Example 1 is obtained by forming an intermediate layer on one surface of a glass substrate and forming a phosphor layer on the intermediate layer. The side surface of the partition wall facing the intermediate layer is a scattering reflection surface that scatters light.

  Table 1 shows the size of the partition opening, the height of the intermediate layer, the aspect ratio of the intermediate layer, the refractive index of the intermediate layer, the refractive index of the phosphor layer, and the partition in each of Comparative Example 3, Comparative Example 4 and Example 1. This is a summary of the reflectance, the reflection characteristics of the partition walls, and the extraction efficiency.

  As shown in Table 1, the extraction efficiency of Example 1 was improved as compared with Comparative Examples 3 and 4. The reason why the extraction efficiency was improved in Example 1 compared with Comparative Example 3 is considered that a part of the light emitted from the phosphor layer at a large angle was scattered by the partition walls and extracted outside the glass substrate. It is done.

  In Comparative Example 4, as in Example 1, an intermediate layer is provided between the phosphor layer and the glass substrate, and the periphery of the intermediate layer and the phosphor layer is surrounded by partition walls. Comparative Example 4 is a comparative example. Compared with Example 3, the removal efficiency deteriorated. The reason is considered that the partition walls do not have light scattering properties, and light incident on the partition walls is reflected to the glass substrate side at the same angle.

  That is, as shown in FIG. 10, when the reflection characteristic of the partition has regular reflection characteristics, the incident angle θ to the partition and the incident angle θ to the glass substrate are equal. Therefore, the light reflected by the partition wall and incident on the glass substrate repeats total reflection inside the glass substrate and is confined inside the glass substrate. In Comparative Example 4, compared with Comparative Example 3, light emitted from the phosphor layer in the wide-angle direction is multiple-scattered by the barrier ribs. Therefore, it is considered that light loss due to reflection occurs and the extraction efficiency slightly decreases.

  From the above, it is important that the partition walls have light scattering properties in order to improve the extraction efficiency.

  FIG. 11 is a diagram showing a correlation between the reflectance R of the partition wall and the extraction efficiency η.

  Part of the light incident on the partition walls is scattered by the partition walls and extracted outside the substrate. However, the remaining part is reflected toward the partition wall and repeats scattering. If the partition wall reflectance R is sufficiently large, the light loss during scattering is small, but if the partition wall reflectance R is small, the light loss due to multiple scattering cannot be ignored. The probability that multiple scattering occurs increases as the aspect ratio A of the intermediate layer increases. Therefore, the extraction efficiency varies greatly depending on the reflectance R of the partition walls and the aspect ratio A of the intermediate layer.

  For example, as shown in FIG. 11, when the aspect ratio A is 0, since the phosphor layer and the substrate are in contact, all the light emitted from the phosphor layer is the substrate except for the light emitted in the horizontal direction. Is incident on. Of the light incident on the substrate, the light extracted outside the substrate is only the light incident on the interface between the substrate and the air layer at an angle less than the critical angle. Therefore, the extraction efficiency is uniquely determined by the fluorescence radiation angle distribution and the critical angle. The reason why the extraction efficiency η slightly changes depending on the reflectance R of the barrier ribs is that light emitted in the horizontal direction from the side surface of the phosphor layer is scattered by the barrier ribs and extracted outside the substrate.

  As the aspect ratio A increases, the possibility of multiple scattering increases. Therefore, the extraction efficiency η also varies greatly depending on the reflectance R of the partition wall. In the region where the reflectance R of the partition wall is small, the extraction efficiency η decreases as the aspect ratio A increases. In FIG. 11, “◯” indicates the configuration of Comparative Example 3, and “□” indicates the configuration of Example 1.

  12 and 13 plot the data of FIG. 11 with the horizontal axis representing the aspect ratio A of the intermediate layer and the vertical axis representing the extraction efficiency η. In FIG. 12, “◯” indicates the configuration of Comparative Example 3, and “□” indicates the configuration of Example 1.

  As shown in FIG. 12, the extraction efficiency η draws a mountain-shaped curve as the aspect ratio A increases. In a region where the aspect ratio A is small, the extraction efficiency η increases as the aspect ratio A increases. On the other hand, in the region where the aspect ratio A is large, the extraction efficiency η decreases as the aspect ratio A increases. The extraction efficiency η takes a maximum value at a predetermined aspect ratio A. The aspect ratio A that maximizes the extraction efficiency η is determined for each reflectance R of the partition wall. However, if the reflectance R of the partition wall is too small, the extraction efficiency η only decreases monotonously even when the aspect ratio A increases, and the extraction efficiency η becomes larger than when the aspect ratio A is 0. There is no.

  In FIG. 13, “□” indicates the maximum value of the extraction efficiency η determined for each reflectance R of the partition wall, and “◯” indicates a range in which the extraction efficiency η does not fall below the value when the aspect ratio A = 0. Shows the maximum aspect ratio that can be taken.

  The total light reflectance of the partition wall is R, the extraction efficiency η when R = r is η <r>, the extraction efficiency η <r> when A = a is η <r / a>, η <r / If Amax <r> is the maximum value of A where a> ≧ η <r / 0> and Aopt <r> is Aopt <r> where η <r> is the maximum value, then Aopt <r> determined for each reflectance R. And Amax <r> are indicated by “□” and “◯”, respectively.

  The “total light reflectance of the partition wall” is a component excluding the light amount transmitted through the partition wall and the light amount absorbed by the partition wall from the light amount irradiated on the partition wall. The measurement method is not limited as long as it is a system capable of measuring the light quantity defined above, but is measured using, for example, a spectrocolorimeter CM-2600d (manufactured by Konica Minolta).

  When the reflectance R is 60% or less, the increase in the extraction efficiency η is negligible even when the aspect ratio A is increased. A significant increase in the extraction efficiency η is recognized in a region where the reflectance R is larger than 60%, and preferably in a region where the reflectance R is 70% or more. When the reflectance R is 99%, the maximum value (Aopt <r>) and Amax <r> of η <r> exist in a region where the aspect ratio A is larger than 2.

  FIG. 14 is a plot of the optimum value of the aspect ratio A of the intermediate layer and the upper limit value of the aspect ratio A of the intermediate layer, with the reflectance R of the partition walls as the horizontal axis.

  In FIG. 14, the optimum value of the aspect ratio A is the aspect ratio A (Aopt <r>) when η <r> indicated by “□” in FIG. 13 takes the maximum value, and the upper limit value of the aspect ratio A Is Amax <r> indicated by “◯” in FIG. FIG. 14 shows a fitting curve and a fitting function obtained from the data “□” and “◯”.

  As described above, a significant increase in the extraction efficiency η is recognized in the region where the reflectance R is larger than 60%, and preferably in the region where the reflectance R is 70% or more. When the aspect ratio A exceeds Amax <r>, the extraction efficiency η becomes smaller than when the aspect ratio A = 0. Therefore, in order to increase the extraction efficiency, the reflectance R and the aspect ratio A are in a range satisfying the relationship of 100% ≧ R ≧ 70% and Amax <r >> A> 0 (hatching is performed in FIG. 14). Range) is preferable.

  The aspect ratio A is measured with an optical microscope or a scanning electron microscope (SEM) by preparing a cross-sectional sample shown in FIG. For example, VHX-2000 manufactured by Keyence can be used as the optical microscope, but it is not limited as long as it is an optical microscope having equivalent performance. As the scanning electron microscope, for example, Hitachi High-Tech Model No. SU8020 can be used, but any scanning electron microscope having equivalent performance may be used, and is not limited. The cross sections of the phosphor layer, the intermediate layer, and the barrier ribs can be obtained by cleaving the phosphor substrate perpendicular to the thickness direction of the phosphor layer.

  As described above, according to the phosphor substrate 100 of the present embodiment, the intermediate layer 107 is formed between the substrate 101 and the phosphor layer 102, and light emitted from the phosphor layer 102 passes through the intermediate layer 107. Incident on the substrate 101. Since the phosphor layer 102 and the substrate 101 are separated from each other by the intermediate layer 107, the angle of the light 108a that directly enters the substrate 101 without entering the partition wall 111 from the phosphor layer 102 is limited to a narrow angle range.

  Since the light emitted from the phosphor layer 102 in the wide-angle direction does not directly enter the substrate 101, the light confined inside the substrate 101 by total reflection is reduced. Further, a part of the light emitted from the lower surface of the phosphor layer 102 toward the substrate 101 at an angle equal to or larger than the critical angle is scattered by the partition wall 111, and after the reflection angle is changed, again at an angle smaller than the critical angle. It enters the interface 101b with the air layer and is taken out to the air layer side. Therefore, light emitted at a large angle in the horizontal direction can also be efficiently extracted outside the substrate 101.

  As described above, light emitted from the phosphor layer 102 can be efficiently extracted outside the substrate 101.

[Second Embodiment]
FIG. 15 is a schematic cross-sectional view of a display device 500 including the phosphor substrate 520 of the second embodiment.

  A display device 500 according to this embodiment includes a phosphor substrate 520, an excitation light source 514, and a liquid crystal layer 515. The excitation light source 514 is a light source device that emits excitation light FL having a wavelength of 405 nm, for example. The liquid crystal layer 515 is a known liquid crystal layer that controls the incidence of the excitation light FL on the phosphor substrate 520.

  The phosphor substrate 520 includes a light-transmitting substrate 501, a light-transmitting intermediate layer 507 formed on one surface 501a of the substrate 501, a phosphor layer 502 formed on the intermediate layer 507, and an intermediate layer 507. And a light-scattering partition wall 511 provided on one surface 501a of the substrate 501 so as to surround the side surface of the substrate 501.

  In the phosphor substrate 520, the side opposite to the surface facing the substrate 501 of the phosphor layer 502 is an excitation light incident surface Ef on which the excitation light FL that excites the phosphor layer 502 is incident. A band pass filter layer 505 is preferably formed on the excitation light incident surface Ef of the phosphor layer 502. The band-pass filter layer 505 is a wavelength selection layer that transmits the excitation light FL and reflects light emitted from the phosphor layer 502 by the excitation light FL.

  The phosphor layer 502 includes a plurality of types (three types in this embodiment) of phosphors 503B, 503G, and 503R. The phosphors 503B, 503G, and 503R are formed into spherical or indeterminate granular materials regardless of whether they are organic phosphors or inorganic phosphors. The phosphors 503B, 503G, and 503R have different shapes. Or the same shape. Further, the phosphors 503B, 503G, and 503R may have different dimensions or the same dimensions.

  A light-transmitting intermediate layer 507 is formed between the phosphor layer 502 and the substrate 501. The phosphor layer 502 is formed so as to overlap the intermediate layer 507. The phosphor layer 502 and the intermediate layer 507 rise from one surface 501a of the substrate 501, and are divided into predetermined regions (first to third) by partition walls 511 surrounding the side surfaces along the thickness direction of the phosphor layer 502 and the intermediate layer 507. ). A region (side surface 511a) facing at least the phosphors 503B, 503G, and 503R and the intermediate layer 507 of the partition wall 511 has light scattering properties. A light shielding layer 512 is preferably formed between the bottom of each partition wall 511 and the substrate 501. The material, thickness, shape, manufacturing method, and the like of the partition walls 511 and the intermediate layer 507 are the same as those in the first embodiment. The aspect ratio of the intermediate layer 507 is determined by the same design concept as in the first embodiment.

  For each region partitioned by the partition 511, a green phosphor 503G disposed in the first partition, a red phosphor 503R disposed in the second partition, and a blue phosphor 503B disposed in the third partition are provided. Each is filled. The emission main wavelength (peak wavelength range) of the green phosphor 503G (first phosphor) is 500 to 560 nm. The emission main wavelength (peak wavelength range) of the red phosphor 503R (second phosphor) is 600 to 650 nm. The emission main wavelength (peak wavelength range) of the blue phosphor 503B (third phosphor) is 430 to 490 nm.

  Between the red phosphor 503R, the green phosphor 503G, the blue phosphor 503B, and the substrate 501, a red filter 513R, a green filter 513G, and a blue filter 513B, which are color filters partitioned by a light shielding layer 512, are formed. Yes. The intermediate layer 507 is formed so as to overlap the red filter 513R, the green filter 513G, and the blue filter 513B.

  The green filter 513G arranged in the first section has a maximum transmittance in a wavelength range of 500 to 560 nm (green light), and has a light transmittance in a wavelength range of 500 to 560 nm (green light). , 430 to 490 nm (blue light) and 600 to 650 nm (red light).

  The red filter 513R arranged in the second section has a maximum transmittance in the wavelength region of 600 to 650 nm (red light), and has a light transmittance in the wavelength region of 600 to 650 nm (red light). , 430 to 490 nm (blue light) and 500 to 560 nm (green light).

  The blue filter 513B arranged in the third section has a maximum transmittance in the wavelength region of 430 to 490 nm (blue light), and has a light transmittance in the wavelength region of 430 to 490 nm (blue light). , 500 to 560 nm (green light) and 600 to 650 nm (red light).

  FIG. 28 shows a graph in which the transmission wavelength regions of the red filter 513R, the green filter 513G, and the blue filter 513B are measured. In this graph, for example, the red filter 513R is 600 to 650 nm, the green filter, with the wavelength range having the maximum transmittance centered on light in the wavelength range where the transmittance is 50% or more as the main transmission wavelength region of each filter. 513G transmits light in the wavelength range of 500 to 560 nm, and the blue filter 513B transmits light in the wavelength range of 430 to 490 nm.

  Table 2 shows the maximum transmittance (%) and the minimum transmittance (%) of red light, green light, and blue light in each filter.

  As the red filter 513R, the green filter 513G, and the blue filter 513B, known color filters can be used. Here, by providing the color filter, the color purity of the red pixel, the green pixel, and the blue pixel partitioned by the partition wall 511 can be increased, and the color reproduction range of the display device 500 can be expanded.

FIG. 16 shows an example of the emission spectrum of the green phosphor 503G (SrSi ₂ (O, Cl) ₂ N ₂ : Eu ²⁺ ) arranged in the first section and the transmission spectrum of the green filter 513G arranged in the first section. Indicates. Although the emission spectrum of the green phosphor 503G has an emission peak at about 540 nm, it has a tail to a wavelength of about 650 nm and has a significant red component. However, since the emission spectrum of the green phosphor 503G that has passed through the green filter 513G is obtained by multiplying the emission spectrum of the green phosphor 503G by the transmission spectrum of the green filter 513G, it becomes a sharper spectrum and increases the color purity. Can do.

  Further, the blue filter 513B facing the blue phosphor 503B, the green filter 513G facing the green phosphor 503G, and the red filter 513R facing the red phosphor 503R are not absorbed by the phosphors 503R, 503G, and 503B. Therefore, it is possible to prevent a decrease in color purity of light emission due to a mixture of light emitted from the phosphors 503R, 503G, and 503B and excitation light.

  Further, external light (light incident from the outside of the substrate) is absorbed by the blue filter 513B facing the blue phosphor 503B, the green filter 513G facing the green phosphor 503G, and the red filter 513R facing the red phosphor 503R. Therefore, it is possible to reduce / prevent emission of the phosphors 513R, 513G, and 513B in the unintended pixel due to external light, and to reduce / prevent a decrease in contrast.

  The vertical and horizontal size of the opening section (one section of the phosphor layer) partitioned by the partition walls 511 is preferably about 20 μm × 20 μm to about 500 μm × 500 μm. The opening portion of the partition wall 511 refers to a region for one partition of the partition wall 511 surrounding the one intermediate layer 507. In the case of this embodiment, since the partition wall 511 is erected on the substrate 501 so as to surround the side surfaces of the intermediate layer 507 and the phosphor layer 502, one intermediate layer 507 and one phosphor layer 502 (red, green, A region corresponding to one section of the partition wall 511 surrounding a portion emitting light of a specific color selected from blue is an opening of the partition wall 511. The partition 511 preferably has a reflectance of 80% or more in the CIE 1976 L * a * b display system.

  Also in the phosphor substrate 520 of the present embodiment, since the substrate 501 and the phosphor layer 502 are separated from each other by the intermediate layer 507, the incident angle range of direct light directly incident on the substrate 501 from the phosphor layer 502 is limited. The Since light emitted from the phosphor layer 502 in the wide-angle direction does not directly enter the substrate 501, less light is confined inside the substrate 501 due to total reflection. Further, part of light emitted from the lower surface of the phosphor layer 502 toward the substrate 501 at an angle equal to or greater than the critical angle is scattered by the partition 511, and after the reflection angle is changed, the angle is again smaller than the critical angle. It enters the interface with the air layer and is taken out to the air layer side. Therefore, light emitted at a large angle in the horizontal direction can also be efficiently extracted outside the substrate 501. As described above, light emitted from the phosphor layer 502 can be efficiently extracted outside the substrate 501.

[Third Embodiment]
FIG. 17 is a schematic cross-sectional view showing the phosphor substrate 521 of the third embodiment.

  In the display device 500 shown in FIG. 15, the color filters 513B, 513G, and 513R, the intermediate layer 507, and the phosphor layer 502 are sequentially stacked in each section partitioned by the partition 511. In this configuration, the intermediate layer 507 is configured as a colorless and transparent resin, but the color filters 513B, 513G, and 513R may be omitted, and the function of the color filter may be imparted to the intermediate layer. For example, in the phosphor substrate 521 of the present embodiment, the red intermediate layer 517R, the green intermediate layer 517G, and the blue intermediate layer 517B are respectively disposed between the red phosphor 503R, the green phosphor 503G, the blue phosphor 503B, and the substrate 501. Is formed.

  The green intermediate layer 517G disposed in the first section has a maximum transmittance in the wavelength range of 500 to 560 nm (green light), and also has a light transmittance in the wavelength range of 500 to 560 nm (green light). Is a filter larger than the maximum transmittance of light in each wavelength region of 430 to 490 nm (blue light) and 600 to 650 nm (red light).

  The red intermediate layer 517R disposed in the second section has a maximum transmittance in the wavelength region of 600 to 650 nm (red light), and also has a light transmittance in the wavelength region of 600 to 650 nm (red light). Is a filter larger than the maximum transmittance of light in each wavelength region of 430 to 490 nm (blue light) and 500 to 560 nm (green light).

  The blue intermediate layer 517B arranged in the third section has a maximum transmittance in the wavelength region of 430 to 490 nm (blue light), and also has a light transmittance in the wavelength region of 430 to 490 nm (blue light). Is a filter larger than the maximum transmittance of light in each wavelength region of 500 to 560 nm (green light) and 600 to 650 nm (red light).

  The transmission wavelength regions of the red intermediate layer 517R, the green intermediate layer 517G, and the blue intermediate layer 517B are the same as those shown in FIG. For example, the wavelength range in which the transmittance centering on the light in the wavelength region where the transmittance is 50% or more is the main transmission wavelength region of each filter, the red intermediate layer 517R is 600 to 650 nm, and the green intermediate layer 517G is 500 to 560 nm, and the blue intermediate layer 517B transmits light in the wavelength range of 430 to 490 nm.

  The aspect ratios of the red intermediate layer 517R, the green intermediate layer 517G, and the blue intermediate layer 517B arranged in each of the first section, the second section, and the third section are based on the same design concept as in the first embodiment. Determined. Therefore, also in this embodiment, a phosphor substrate 521 that can efficiently extract the light emitted from the phosphor layer 502 to the outside of the substrate 501 is provided.

[Fourth Embodiment]
FIG. 18 is a schematic cross-sectional view of the phosphor substrate 522 of the fourth embodiment.

  In the display device 500 shown in FIG. 15, one type of phosphor is arranged in each section partitioned by the partition 511, but two or more types of phosphors may be arranged in one section. . For example, in the phosphor substrate 522 of the present embodiment, two types of green phosphors 503G1 and 503G2 are arranged in the first section of the phosphor layer 502. The two types of green phosphors 503G1 and 503G2 have emission main wavelengths different from each other in the emission main wavelength (peak wavelength region) range of 500 to 560 nm. The phosphors arranged in one section may be a plurality of types of phosphors having different average particle diameters.

[Fifth Embodiment]
FIG. 19 is a schematic cross-sectional view of a display device 600 including the phosphor substrate 650 of the fifth embodiment.

  A display device 600 according to this embodiment includes a phosphor substrate 650, an excitation light source 614, and a liquid crystal layer 615. The excitation light source 614 is a light source device that emits excitation light FL having a wavelength of 450 nm, for example. The liquid crystal layer 615 is a known liquid crystal layer that controls the incidence of the excitation light FL on the phosphor substrate 650.

  The phosphor substrate 650 includes a light transmissive substrate 601, a light transmissive intermediate layer 607 formed on one surface 601 a of the substrate 601, a phosphor layer 602 formed on the intermediate layer 607, and an intermediate layer 607. And a light-scattering partition wall 611 standing on the one surface 601a of the substrate 601.

  The phosphor substrate 650 has an excitation light incident surface Ef on which the excitation light FL for exciting the phosphor layer 602 is incident on the opposite side of the phosphor layer 602 from the surface facing the substrate 601. A band pass filter layer 605 is preferably formed on the excitation light incident surface Ef of the phosphor layer 602. The bandpass filter layer 605 is a wavelength selection layer that transmits the excitation light FL and reflects the light emitted from the phosphor layer 602 by the excitation light FL.

  This embodiment is greatly different from the second embodiment in that light scattering particles 603S are arranged on the phosphor layer 602 of the blue pixel instead of the phosphor.

  The phosphor layer 602 includes a plurality of types (two types in this embodiment) of phosphors 603G and 603R and light scattering particles 603S. The light scattering particles 603S perform blue display by scattering the blue excitation light FL. As the phosphors 603G and 603R, the same phosphors 503G and 503R as those of the second embodiment are used.

  Other materials such as the substrate 601 of the phosphor substrate 650, the intermediate layer 607, the phosphor layer 602, the partition 611, the light shielding layer 612, the red filter 613R, the green filter 613G, the blue filter 613B, and the bandpass filter 605, The manufacturing method and the like are the same as those in the second embodiment. The aspect ratio of the intermediate layer 607 is determined by the same design concept as in the first embodiment.

  The light scattering particles 603S may be made of an organic material or may be made of an inorganic material, but is preferably made of an inorganic material. This makes it possible to diffuse or scatter light having directivity from the outside (for example, a light emitting element) more isotropically and effectively. Further, by using an inorganic material, it is possible to provide a light scattering layer that is stable to light and heat. The light scattering particles 603S are preferably highly transparent. Further, it is preferable that particles having a higher refractive index than the base material are dispersed in the low refractive index base material. In addition, in order for blue light to be effectively scattered by the light-scattering particles 603S, the particle size of the light-scattering particles 603S needs to be in the Mie scattering region. Is preferably about 100 nm to 500 nm.

  When an inorganic material is used as the light scattering particle 603S, for example, an oxide of at least one metal selected from the group consisting of silicon, titanium, zirconium, aluminum, indium, zinc, tin, and antimony is used as a main component. And the like.

Further, when using particles (inorganic particles) made of an inorganic material as the light scattering particles 603S, for example, silica beads (refractive index: 1.44), alumina beads (refractive index: 1.63), Titanium oxide beads (refractive index anatase type: 2.50, rutile type: 2.70), zirconia oxide beads (refractive index: 2.05), zinc oxide beads (refractive index: 2.00), barium titanate (BaTiO) ₃ ) (refractive index: 2.4) and the like.

  When using particles (organic particles) made of an organic material as the light scattering particles 603S, for example, polymethyl methacrylate beads (refractive index: 1.49), acrylic beads (refractive index: 1.50), Acrylic-styrene copolymer beads (refractive index: 1.54), melamine beads (refractive index: 1.57), high refractive index melamine beads (refractive index: 1.65), polycarbonate beads (refractive index: 1.57) ), Styrene beads (refractive index: 1.60), crosslinked polystyrene beads (refractive index: 1.61), polyvinyl chloride beads (refractive index: 1.60), benzoguanamine-melamine formaldehyde beads (refractive index: 1.68). ), Silicone beads (refractive index: 1.50), and the like.

  The resin material used by mixing with the light-scattering particles 603S is preferably a resin that has optical transparency to excitation light. Examples of the resin material include acrylic resin (refractive index: 1.49), melamine resin (refractive index: 1.57), nylon (refractive index: 1.53), polystyrene (refractive index: 1.60). , Melamine beads (refractive index: 1.57), polycarbonate (refractive index: 1.57), polyvinyl chloride (refractive index: 1.60), polyvinylidene chloride (refractive index: 1.61), polyvinyl acetate ( Refractive index: 1.46), polyethylene (refractive index: 1.53), polymethyl methacrylate (refractive index: 1.49), poly MBS (refractive index: 1.54), medium density polyethylene (refractive index: 1) .53), high density polyethylene (refractive index: 1.54), tetrafluoroethylene (refractive index: 1.35), poly (trifluoroethylene chloride) (refractive index: 1.42), polytetrafluoroethylene (refractive index) : .35), and the like.

  In the phosphor substrate 650 of the present embodiment, the same effect as that of the second embodiment can be obtained. In the present embodiment, since the blue phosphor is replaced with the light scattering particles 603S, there is an advantage that the phosphor substrate 650 can be manufactured at low cost.

[Sixth Embodiment]
FIG. 20A is a schematic cross-sectional view of the phosphor substrate 700 of the sixth embodiment.
FIG. 20B is a schematic plan view of the phosphor substrate 700 shown in FIG.

  The phosphor substrate 700 according to the present embodiment includes a light transmissive substrate 701, a light transmissive intermediate layer 707 formed on one surface 701a of the substrate 701, and a phosphor layer 702 formed on the intermediate layer 707. And a light-scattering partition wall 711 erected on one surface 701a of the substrate 701 so as to surround the side surface of the intermediate layer 707.

  In the phosphor substrate 700, the side opposite to the surface facing the substrate 701 of the phosphor layer 702 becomes an excitation light incident surface on which excitation light for exciting the phosphor layer 702 is incident. A band pass filter layer 705 is preferably formed on the excitation light incident surface of the phosphor layer 702. The band pass filter layer 705 is a wavelength selection layer that transmits excitation light and reflects fluorescence generated in the phosphor layer 702 by the excitation light.

  This embodiment is greatly different from the second embodiment in that a region for one section of the phosphor layer 702 partitioned by the partition 711 is further partitioned into a plurality of regions by the partition 718. In this embodiment, as an example, the size of one section partitioned by the partition 711 is 100 μm × 300 μm, and the size of one section partitioned by the partition 711 and the partition 718 is 100 μm × 50 μm. The width of the partition 718 in the short direction is 33 μm, and the height of the partition 718 is 30 μm.

  For example, the intermediate layer 707 rises from one surface 701 a of the substrate 701, and is divided into predetermined regions by partition walls 711 and partition walls 718 surrounding the side surfaces of the intermediate layer 707 along the thickness direction. Regions (side surface 711a and side surface 718a) facing at least the intermediate layer 707 and the phosphor layer 702 of the partition wall 711 and the partition wall 718 have light scattering properties. A light shielding layer 712 is preferably formed between the bottom of each of the partition walls 711 and 718 and the substrate 701.

  The first compartment, the second compartment, and the third compartment defined by the partition 711 are filled with a green phosphor 703G, a red phosphor 703R, and a blue phosphor 703B, respectively. As the phosphors 703R, 703G, and 703B, the same phosphors as the phosphors 503R, 503G, and 503B of the second embodiment are used. Between the red phosphor 703R, the green phosphor 703G, the blue phosphor 703B, and the substrate 701, a color filter partitioned by a light shielding layer 712 may be formed.

  Other materials, thicknesses, shapes, manufacturing methods, and the like of the substrate 701, the intermediate layer 707, the phosphor layer 702, the partition 711, the partition 718, the light shielding layer 712, and the bandpass filter 705 of the phosphor substrate 700 are the second embodiment. Is the same. The aspect ratio of the intermediate layer 707 is determined by the same design concept as in the first embodiment.

  Also in the phosphor substrate 700 of the present embodiment, the same effects as in the second embodiment can be obtained. In the present embodiment, the first partition, the second partition, and the third partition partitioned by the partition 711 are further partitioned by the partition 718. Therefore, even if the size per partition by the partition 711 increases, the extraction efficiency is unlikely to decrease.

[Seventh Embodiment]
FIG. 21A is a schematic cross-sectional view of the phosphor substrate 750 of the seventh embodiment.
FIG. 21B is a schematic plan view of the phosphor substrate 750 shown in FIG.

  The phosphor substrate 750 according to this embodiment includes a light transmissive substrate 751, a light transmissive intermediate layer 757 formed on one surface of the substrate 751, and a phosphor layer 752 formed on the intermediate layer 757. And a light-scattering partition wall 761 erected on one surface of the substrate 751 so as to surround the side surface of the intermediate layer 757.

  In the phosphor substrate 750, the side opposite to the surface facing the substrate 751 of the phosphor layer 752 is an excitation light incident surface on which excitation light for exciting the phosphor layer 752 is incident. A band pass filter layer 755 is preferably formed on the excitation light incident surface of the phosphor layer 752. The bandpass filter layer 755 is a wavelength selection layer that transmits excitation light and reflects fluorescence generated in the phosphor layer 752 by the excitation light.

  The phosphor substrate 750 is formed by bonding a first substrate 765 and a second substrate 766. The first substrate 765 is erected on one surface of the substrate 751 so as to surround the side surface of the light-transmissive substrate 751, the light-transmissive intermediate layer 757 formed on one surface of the substrate 751, and the intermediate layer 757. A light-scattering partition wall 761. The second substrate 766 is erected on one surface of the bandpass filter 755, the phosphor layer 752 formed on one surface of the bandpass filter 755, and the side surface of the phosphor layer 752. A light-scattering partition wall 756.

  The first substrate 765 and the second substrate 766 are bonded to each other with the surfaces on which the intermediate layer 757 and the phosphor layer 752 are formed facing each other. Note that a light-blocking layer 762 is preferably formed between the bottom of the partition wall 761 and the substrate 751.

  In this embodiment, as an example, the size of one section partitioned by the partition wall 761 is 50 μm × 50 μm, and the size of one section partitioned by the partition wall 756 is 200 μm × 1000 μm. The first compartment, the second compartment, and the third compartment defined by the partition 756 are filled with a green phosphor 753G, a red phosphor 753R, and a blue phosphor 753B, respectively. As the phosphors 753R, 753G, and 753B, those similar to the phosphors 503R, 503G, and 503B of the second embodiment are used.

  In the phosphor substrate 700 according to the sixth embodiment shown in FIG. 20, a region corresponding to one partition of the phosphor layer 702 is equally partitioned into a plurality of regions by the partition 718. In each section, an intermediate layer 707 is formed, and a phosphor layer 702 is formed on the intermediate layer 707 so as to overlap therewith. On the other hand, in the phosphor substrate 750 of the present embodiment, the partition 756 that partitions the phosphor layer 752 and the partition 761 that partitions the intermediate layer 757 are formed on different base materials. Then, the phosphor substrate 750 is manufactured by bonding the two together.

  In the phosphor substrate 750 of the present embodiment, the area (pixels) for one section partitioned by the partition 756 is not necessarily partitioned equally by the partition 761, but this does not significantly affect the light extraction efficiency. . In the case of the present embodiment, since the phosphor layer 752 and the intermediate layer 757 are formed on different base materials, the intermediate layer and the phosphor layer are sequentially formed on the same substrate using two types of partition walls. Manufacturing becomes easier.

  Also in the present embodiment, the first partition, the second partition, and the third partition partitioned by the partition 756 are further finely partitioned by the partition 761. Then, an intermediate layer 757 is formed in each finely partitioned region. Therefore, even if the size per partition by the partition 7561 increases, the extraction efficiency is unlikely to decrease.

[Eighth Embodiment]
FIG. 22 is a schematic sectional view of a light emitting device 800 including the phosphor substrate 810 of the eighth embodiment.

  The light emitting device 800 of this embodiment includes a phosphor substrate 810 and a light source 818. The phosphor substrate 810 includes a light transmissive substrate 801, a light transmissive intermediate layer 807 formed on one surface 801 a of the substrate 801, a phosphor layer 802 formed on the intermediate layer 807, and an intermediate layer 807. And a light-scattering partition wall 811 erected on one surface 801a of the substrate 801.

  In the phosphor substrate 810, the side opposite to the surface facing the substrate 801 of the phosphor layer 802 is an excitation light incident surface on which excitation light that excites the phosphor layer 802 is incident. A band pass filter layer 805 is preferably formed on the excitation light incident surface of the phosphor layer 802. The band pass filter layer 805 is a wavelength selection layer that transmits excitation light and reflects fluorescence generated in the phosphor layer 802 by the excitation light.

  The material, thickness, shape, manufacturing method, and the like of the substrate 801, intermediate layer 807, phosphor layer 802, partition wall 811, and bandpass filter 805 of the phosphor substrate 810 are the same as those in the first embodiment. The aspect ratio of the intermediate layer 807 is determined by the same design concept as in the first embodiment. In the present embodiment, for example, a mixture of a red phosphor 803R that emits red light by excitation light emitted from a light source 818 and a green phosphor 803G that emits green light is used. Reference numeral 808 denotes light generated by color conversion by the phosphor substrate 810.

  The light source 818 includes a base material 813 provided with an LED chip 812, a transparent sealing resin 814 that seals the LED chip 812 to the base material 813, and a reflector formed so as to surround the LED chip 812 and the sealing resin 814. 815, a lead wire 816 of the LED chip 812 formed along the peripheral surface of the base material 813, a wire 817 for connecting the LED chip 812 and the lead wire 816, and the like.

  The wire 817 is, for example, a conductive metal alloy, but gold, gold alloy, aluminum, copper, silver, or the like is mainly used from the viewpoint of easy alloying with the LED chip 812 or the electrode material. Although FIG. 22 shows wire-bonded ones, LED chips 812 may be flip-chip mounted. Further, for the purpose of improving electrostatic characteristics, an electrostatic protection element (for example, a Zener diode or a resistance element) may be connected in parallel with the LED chip 812.

The LED chip 812 is, for example, an LED chip containing GaN that emits blue light (excitation light). The reflector 815 uses nylon-based polyphthalamide (PPA) or silicone-based resin as a molding resin, and a filler for expressing light scattering in the molding resin, for example, TiO ₂ , SiO ₂ , alumina, Consists of dispersed aluminum nitride, mullite, etc.

The sealing resin 814 is made of an epoxy resin, a urea resin, a silicone resin, a modified epoxy resin, a modified silicone resin, polyamide, glass, or the like.
As the phosphor, in addition to mixing the red phosphor 803R and the green phosphor 803G, it is also preferable to use, for example, a yellow phosphor that emits yellow light.

  Like the light emitting device 800 of this embodiment, the phosphor substrate 810 is used for the LED chip 812, thereby improving the light emission luminance and suppressing the variation in manufacturing quality due to the combination of the LED chip 812 and the phosphor substrate 810. The LED chip 812 that emits heat and the phosphors 803R and 803G can be separated from each other to obtain effects such as suppression of deterioration of the phosphors 803R and 803G.

[Ninth Embodiment]
FIG. 23 is a schematic cross-sectional view of a light emitting device 820 including the phosphor substrate 810 of the ninth embodiment.

  The phosphor substrate 810 used in the present embodiment is the same as that in the eighth embodiment. In the light emitting device 800 illustrated in FIG. 22, the light source 818 having a configuration in which one LED chip 812 is disposed on one surface of the base material 813 is used. In the ninth embodiment illustrated in FIG. Are provided with a plurality of LED chips 812, 812. These LED chips 812, 812,... Can be used as a surface light source that is connected in series to illuminate a wide range. The LED chip 812 may be connected in series or in parallel.

[Tenth embodiment]
FIG. 24 is a schematic cross-sectional view of a solar cell module 900 including the phosphor substrate 910 of the tenth embodiment.

  In the solar cell module 900 of this embodiment, a phosphor substrate 910 and a photoelectric conversion element 917 are formed so as to overlap each other.

  The phosphor substrate 910 includes a light transmissive substrate 901, a light transmissive intermediate layer 907 formed on one surface 901 a of the substrate 901, a phosphor layer 902 formed on the intermediate layer 907, and an intermediate layer 907. A light-scattering partition wall 911 standing on a surface 901a of the substrate 901.

  In the phosphor substrate 910, the side opposite to the surface facing the substrate 901 of the phosphor layer 902 becomes an excitation light incident surface on which excitation light that excites the phosphor layer 902 is incident. A band pass filter layer 905 is preferably formed on the excitation light incident surface of the phosphor layer 902. The band pass filter layer 905 is a wavelength selection layer that transmits excitation light and reflects fluorescence generated in the phosphor layer 902 by the excitation light.

  The material, thickness, shape, manufacturing method, and the like of the substrate 901, the intermediate layer 907, the phosphor layer 902, the partition wall 911, and the bandpass filter 905 of the phosphor substrate 910 are the same as those in the first embodiment. The aspect ratio of the intermediate layer 907 is determined by the same design concept as in the first embodiment.

Examples of the photoelectric conversion element 917 include a silicon solar cell, a GaAs solar cell, and a CuInGaSe mixed crystal solar cell (ClGS solar cell). The photoelectric conversion element 917, in addition to those described above, for _{example, InGaP, InGaAs, AlGaAs, Cu} (In, Ga) Se 2, Cu (In, Ga) (Se, S) 2, CuInS 2, CdTe, CdS Etc. can also be used. Furthermore, it is also preferable to use a solar cell having another structure such as a quantum dot solar cell as the photoelectric conversion element.

  As shown in FIG. 25, in any of the crystalline silicon solar cell, the GaAs solar cell, and the ClGS solar cell, the optical power conversion efficiency φ has the maximum conversion efficiency φ at a wavelength determined by the band gap of the material of each solar cell element. Then, the longer wavelength side is steeply lowered, and the conversion efficiency is slowly lowered on the shorter wavelength side.

  On the other hand, as shown in FIG. 26, the spectrum of sunlight (air mass 1.5) rises steeply from a wavelength of about 300 nm, becomes maximum at a wavelength of about 460 nm, and the intensity gradually decreases on the longer wavelength side.

Therefore, if the light on the short wavelength side of sunlight is converted by the phosphor substrate 910 into light having a higher photovoltaic power conversion efficiency φ of the solar cell element, the photoelectric conversion efficiency of the entire solar cell module can be improved. It becomes possible.
On the other hand, when the wavelength of the light converted by the phosphor substrate 910 is longer than the maximum value of the photoelectric conversion efficiency φ of the solar cell element, the photoelectric conversion efficiency of the entire solar cell module is lowered.

FIG. 26 is a graph showing the effect of combining the phosphor substrate 910 with the photoelectric conversion element 917. “A component absorbed by phosphor 903 in the spectrum of sunlight (see FIG. 26)” when red phosphor CaAlSiN ₃ : Eu ²⁺ is used as phosphor 903 constituting phosphor substrate 910 (hereinafter, spectrum I , “Emission spectrum of phosphor substrate 910 (see FIG. 26)” (hereinafter referred to as spectrum II), “sunlight spectrum (air mass 1.5)” (hereinafter referred to as spectrum III), “fluorescence "Spectrum of sunlight passing through body 903" (hereinafter referred to as spectrum IV) and "photopower conversion efficiency φ spectrum of crystalline silicon solar cell (see Fig. 26)" (hereinafter referred to as spectrum V) are shown in an overlapping manner. . According to FIG. 26, with respect to the crystalline silicon solar cell having the characteristic that the photoelectric conversion efficiency increases uniformly toward the long wavelength side, sunlight having a peak on the short wavelength side is caused to be emitted by the phosphor substrate 910. This indicates that the light can be converted to the long wavelength side, whereby the photoelectric conversion efficiency of the photoelectric conversion element 917 by sunlight can be improved.

  More specifically, when the phosphor substrate 910 is irradiated with sunlight from the wavelength selection layer side, the phosphor substrate 910 absorbs the spectrum I, converts the wavelength to the spectrum II, and the light is incident on the photoelectric conversion element 817 side. It is taken out. In addition, the spectrum IV transmitted through the phosphor substrate 910 is also irradiated to the electric conversion element 917.

  When the numerical values are read from FIG. 26, the optical power conversion efficiency φ of the photoelectric conversion element 917 in the wavelength region of the spectrum I, more specifically, about 300 nm to about 600 nm, is 7% to 19%. The optical power conversion efficiency φ of the photoelectric conversion element 917 having a wavelength region of the spectrum II, more specifically, about 600 nm to about 750 nm is 19% to 25%. Comparing both, it can be seen that the photoelectric power conversion efficiency φ of the photoelectric conversion element 917 is higher in the wavelength region of the spectrum II.

Further here
(Left side) [Spectrum I × Photoelectric power conversion efficiency of solar cell φ (Spectrum V)]
Λ
(Right side) [Spectrum II × Quantum efficiency of phosphor × Extraction efficiency × Photoelectric power conversion efficiency of solar cell φ (Spectrum V)]
In this case, the photoelectric conversion efficiency of the entire solar cell module can be improved. The above (left side) does not apply the phosphor substrate 910, and the amount of power generated when sunlight directly enters the photoelectric conversion element 917. It is. The spectrum I and the spectrum V in FIG. 26 are proportional to the overlapping area.

  On the other hand, the above (right side) is the amount of power generated when sunlight is incident on the solar cell module 900 of this embodiment in which the phosphor substrate 910 is directly applied to the photoelectric conversion element 917. When the phosphor substrate 910 absorbs the spectrum I and emits the spectrum II to the photoelectric conversion element 917, the light intensity is reduced by multiplying the quantum efficiency of the phosphor 903 and the extraction efficiency of the phosphor substrate 910. Therefore, the amount obtained by multiplying the spectrum obtained by multiplying the spectrum II by the quantum efficiency and the extraction efficiency of the phosphor by the spectrum V is the power generation amount of the solar cell module 900 of this embodiment. The power generation amount of the solar cell module 900 of this embodiment is proportional to the amount obtained by multiplying the area where the spectrum II and the spectrum V in FIG. 26 overlap with the quantum efficiency and the extraction efficiency of the phosphor.

Therefore, in order to improve the power generation amount of the entire solar cell module, it is necessary that the light extraction efficiency of the phosphor substrate 910 is sufficiently high. By applying the phosphor substrate 910 having the configuration of the present invention, which can be expected to have high extraction efficiency, to the photoelectric conversion element 917, it becomes easy to satisfy the above formula (left side) (right side).
In addition, the phosphor substrate 910 converts the wavelength into a wavelength region where the optical power conversion efficiency φ is high and makes light incident on the photoelectric conversion element 917, so that the temperature increase of the photoelectric conversion element 917 can be suppressed, and the light of the photoelectric conversion element 917 can be suppressed. Degradation of power conversion characteristics can be prevented.
Above (left side)

In FIG. 27, the absorption spectrum (absorption rate) and emission spectrum (light intensity) of the red phosphor (CaAlSiN ₃ : Eu ²⁺ ) constituting the phosphor substrate 910 and the spectrum of sunlight (air mass 1.5), The component which a red fluorescent substance absorbs in the spectrum of sunlight is shown.

  The phosphor substrate and the light emitting device according to the above embodiment can be applied to a mobile phone 1000 as an electronic device, for example, as shown in FIG. A cellular phone 1000 illustrated in FIG. 29A includes a voice input portion 1003, a voice output portion 1004, an antenna 1005, an operation switch 1006, a display portion 1002, a housing 1001, and the like. The phosphor substrate and the light emitting device of the above embodiment can be suitably applied as the display unit 1002. By applying the phosphor substrate and the light emitting device according to the above embodiment to the display portion 1002 of the mobile phone 1000, a high contrast image can be displayed with low power consumption.

  The phosphor substrate and the light emitting device according to the above embodiment can be applied to a thin television 1100 as an electronic apparatus, for example, as shown in FIG. A thin television 1100 illustrated in FIG. 29B includes a display portion 1102, a speaker 1103, a cabinet 1101, a stand 1104, and the like. The phosphor substrate and the light emitting device of the above embodiment can be suitably applied as the display unit 1102. By applying the phosphor substrate and the light-emitting device according to the above embodiment to the display portion 1102 of the thin television 1100, a high-contrast image can be displayed with low power consumption.

  The phosphor substrate and the light emitting device according to the above embodiment can be applied to a ceiling light 1400 as a lighting device, for example, as shown in FIG. A ceiling light 1400 illustrated in FIG. 30A includes a light-emitting portion 1401, a suspended line 1402, a power cord 1403, and the like. The phosphor substrate and light emitting device of the above embodiment can be suitably applied as the light emitting unit 1401. By applying the phosphor substrate and the light-emitting device according to the above embodiment to the light-emitting portion 1401 of the ceiling light 1400, it is possible to obtain illumination light of a free color tone with low power consumption, and realize a lighting device with high light performance. can do. In addition, it is possible to realize a lighting fixture capable of emitting surface light with high color purity with uniform illuminance.

  The phosphor substrate and the light emitting device according to the above embodiment can be applied to a lighting stand 1500 as a lighting device, for example, as shown in FIG. A lighting stand 1500 illustrated in FIG. 30B includes a light-emitting portion 1501, a stand 1502, a main switch 1503, a power cord 1504, and the like. The phosphor substrate and light emitting device of the above embodiment can be suitably applied as the light emitting unit 1501. By applying the phosphor substrate and the light-emitting device according to the above embodiment to the light-emitting portion 1501 of the lighting stand 1500, it is possible to obtain illumination light of a free color tone with low power consumption, and realize a lighting device with high light performance. can do. In addition, it is possible to realize a lighting fixture capable of emitting surface light with high color purity with uniform illuminance.

  The present invention can be used for a phosphor substrate and a display device including the phosphor substrate.

DESCRIPTION OF SYMBOLS 100 ... Phosphor substrate, 101 ... Substrate, 102 ... Phosphor layer, 103 ... Phosphor, 104 ... Binder resin, 105 ... Band pass filter (wavelength selection layer), 107 ... Intermediate layer, 111 ... Partition, 111a ... Side surface, DESCRIPTION OF SYMBOLS 113 ... Filter layer, 500 ... Display apparatus, 501 ... Substrate, 502 ... Phosphor layer, 503R, 503G, 503G1, 503G2, 503B ... Phosphor, 504 ... Binder resin, 505 ... Band pass filter (wavelength selection layer), 507 ... Intermediate layer, 511 ... partition wall, 511a ... side surface, 513R, 513G, 513B ... filter layer, 517R, 517G, 517B ... intermediate layer, 520 ... phosphor substrate, 521 ... phosphor substrate, 522 ... phosphor substrate, 600 ... Display device, 601 ... substrate, 602 ... phosphor layer, 603R, 603G, 603B ... phosphor, 604 Binder resin, 605 ... band pass filter (wavelength selection layer), 607 ... intermediate layer, 611 ... partition wall, 611a ... side face, 613R, 613G, 613B ... filter layer, 650 ... phosphor substrate, 700 ... phosphor substrate, 701 ... Substrate, 702 ... phosphor layer, 703R, 703G, 703B ... phosphor, 704 ... binder resin, 705 ... bandpass filter (wavelength selection layer), 707 ... intermediate layer, 711 ... partition, 711a ... side, 718 ... partition, 750 ... phosphor substrate, 751 ... substrate, 752 ... phosphor layer, 753R, 753G, 753B ... phosphor, 755 ... bandpass filter (wavelength selection layer), 756 ... partition, 757 ... intermediate layer, 761 ... partition, 800 ... Light emitting device, 810 ... Phosphor substrate, 801 ... Substrate, 802 ... Phosphor layer, 803G, 803B ... Fluorescence 804 ... Binder resin, 805 ... Band pass filter (wavelength selection layer), 807 ... Intermediate layer, 811 ... Partition wall, 811a ... Side, 818 ... Light source, 820 ... Light emitting device, 900 ... Solar cell module, 910 ... Phosphor substrate 901 ... Substrate, 902 ... Phosphor layer, 903 ... Phosphor, 904 ... Binder resin, 905 ... Bandpass filter (wavelength selection layer), 907 ... Intermediate layer, 911 ... Partition wall, 911a ... Side, 917 ... Photoelectric conversion element , 1000, 1100 ... electronic equipment, 1400, 1500 ... illumination device, FL ... excitation light

Claims (5)

A light transmissive substrate;
A light transmissive intermediate layer formed on one surface of the substrate;
A phosphor layer formed on the intermediate layer;
A light-scattering partition wall standing on one surface of the substrate surrounding a side surface of the intermediate layer;
A phosphor substrate comprising:   The surface of the intermediate layer facing the substrate is an interface between the substrate and the intermediate layer, and the phosphor layer at a position facing the center of the interface when viewed from the normal direction of the substrate is the center of the phosphor layer. At least part of the light having the emission main wavelength of the phosphor layer emitted from the central portion of the phosphor layer toward the outer edge of the interface is scattered by the barrier ribs. 2, and reaches the substrate without incident, and enters the interface between the substrate and the air layer at an angle smaller than a critical angle determined by a refractive index difference between the substrate and an air layer outside the substrate. Phosphor substrate.   The height of the intermediate layer is h, the shortest length from the center of the interface to the outer edge of the interface is w / 2, the aspect ratio h / w of the intermediate layer is A, and the total emission amount of the phosphor layer is P, the amount of light transmitted through the substrate and extracted outside the substrate, E, the extraction efficiency E / P is η, the total light reflectance of the partition wall is R, and the extraction efficiency η when R = r is When η <r>, the extraction efficiency η <r> when A = a is η <r / a>, and the maximum value of A that satisfies η <r / a> ≧ η <r / 0> is Amax <r 3. The phosphor substrate according to claim 2, wherein when R is greater than 100, the R and the A satisfy a relationship of 100% ≧ R ≧ 70% and Amax <r >> A> 0.   The wavelength selection layer which transmits the excitation light which excites the said phosphor layer, and reflects the fluorescence produced in the said phosphor layer by the said excitation light is formed on the said phosphor layer. The phosphor substrate according to any one of the above.   A display device comprising a light emitting device comprising: the phosphor substrate according to claim 1; and a light source that emits excitation light that excites the phosphor layer.

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