Display device and wavelength conversion substrate

Abstract

To improve brightness of display in a display device.SOLUTION: A display device 100 includes: a first transparent board 110; a color filter 2 facing the first board 110 in a thickness direction; a first black matrix layer 1 in which plural pixel openings Or, Og, Ob going toward the color filter 2 while facing the first board 110 are formed; a light-reflective matrix layer 6 laminated on a lower layer 1b; a wavelength conversion layer 3 that is disposed so as to be overlapped with at least one of the plural pixel openings Or, Og, Ob in a plan view and converts a wavelength of light going toward the color filter 2; plural light-emitting elements 24 for radiating light toward each of the plural pixel openings Or, Og, Ob from an opposite side of the first board 110 while sandwiching the first black matrix layer 1; and a second board 120 disposed to face the first board 110 while the plural light-emitting elements 24 are disposed.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a display device and a wavelength conversion substrate. [Background technology]

[0002] A liquid crystal display device is a display device that uses a backlight with an LED (Light Emitting Diode) as a light source, and uses liquid crystal as a display functional layer that switches between transmitting and blocking light.

[0003] In recent years, a technology that uses direct-type backlights called mini-LEDs, which have multiple LED chips with sizes of approximately 50 μm to 200 μm arranged in a matrix, has been attracting attention in liquid crystal display devices. Mini-LEDs usually use direct-type backlight units in which multiple LED chips (hereinafter sometimes referred to as light-emitting elements) are arranged.

[0004] Also attracting attention is a technology that uses local dimming in which the luminance of an LED chip is partially adjusted or the light emission is partially stopped depending on the position of the display part on the display screen.

[0005] Micro LED is a display device that has a structure in which LED chips of about 2μm to 50μm in size are arranged in a matrix and displays by driving each of the multiple LED chips individually. Such micro LED can display without using liquid crystal.

[0006] Micro LEDs are broadly divided into a system that uses three types of LED elements that emit red, green, and blue light, and a system that uses only single-color LED elements such as LED chips that emit light in the blue to near-ultraviolet wavelength range. In micro LEDs, each LED element plays the role of a display function layer. The system that uses three types of LED elements that emit red, green, and blue light has the disadvantages that mounting is difficult because the LED elements with different emitting colors have different heights, and that it requires more LED mounting processes than using single-color LEDs, which increases costs, and that the driving voltages are different for each type, making it difficult to control.

[0007] In the method using monochromatic LED elements, color display is achieved by stacking a wavelength conversion layer (e.g., a dispersion of quantum dots or inorganic phosphors) on each of multiple monochromatic LED elements, which converts the emission wavelength to either red, green, or blue.

[0008] Patent Document 1 discloses a technique for providing light-scattering or light-reflective partitions as a phosphor substrate in order to effectively utilize light emitted from a light source such as an LED or an organic EL. The partition shape described in Patent Document 1 is a shape in which the cross-sectional area when cut along a plane parallel to one surface of the substrate is smaller on the side away from the substrate and larger in the direction toward the substrate, as described in claim 1. Patent Document 1 also describes that the partition may have light scattering or light reflecting properties for the purpose of reflecting fluorescence generated in the phosphor layer (see paragraph 0052).

[0009] In order to effectively utilize the light emitted from a light source such as an LED, Patent Document 2 discloses a technique in which a current injection limiting layer in the light source is formed of a metal reflective layer. Patent documents 1 and 2 disclose a technology in which the excitation light is blue light (a monochromatic blue light source) and a technology in which the excitation light is ultraviolet light (e.g., a monochromatic purple or UV region light source), and also disclose a color conversion layer or phosphor layer that converts this monochromatic light into red or green light. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] JP 2015-64391 A [Patent Document 2] JP 2019-87746 A Summary of the Invention [Problem to be solved by the invention]

[0011] In conventional liquid crystal display devices, micro LEDs, and organic EL display devices, the linearity of the light emitted from the display function layer toward the pixel aperture is not sufficient. Therefore, stray light (light in an oblique direction) occurs in adjacent pixels, reducing the display contrast. As pixel size becomes smaller, the reduction in display contrast caused by stray light becomes a problem. In addition, when a display device is used in a bright environment, the reduction in display contrast caused by incident light entering the display device from the outside also becomes a problem.

[0012] In addition, in liquid crystal display devices, micro LEDs, and organic EL display devices, the pixel aperture ratio tends to decrease with increasing resolution, resulting in a decrease in display brightness (luminance). In other words, the area ratio of the light-absorbing black matrix increases, resulting in a problem of ineffective use of the emitted light from the LED light source.

[0013] 11 shows a conventional example of a display device equipped with a direct type backlight unit 53 that uses blue LEDs as light emitting elements 54. In this conventional example, a liquid crystal panel 58 is shown as a display functional part above the direct type backlight unit 53. A color filter including a black matrix is ​​disposed on the liquid crystal panel 58. To indicate pixel positions, pixels a, b, c, d, e, and f are shown in the liquid crystal panel 58.

[0014] The direct type backlight unit 53 includes a plurality of light emitting elements 54, and above the arrangement of the light emitting elements 54, a diffusion plate 55, a wavelength conversion sheet 56, and a prism sheet 57. The light emitting elements 54 are often a plurality of LED chips individually packaged in a metal housing. The wavelength conversion sheet 56 is for converting blue light from some of the plurality of blue emitting elements 54 into red and green light, thereby obtaining three colors, red, green and blue, as a whole. Prism sheet 57 is formed by, for example, laminating two sheets whose prisms extend in directions perpendicular to each other.

[0015] The light-emitting part of these LED chips is generally filled with phosphors and light-scattering particles together with silicone resin. Since LED light is highly linear and emitted from the center of the LED chip, one of the roles of these phosphors and light-scattering particles is to scatter light in order to expand the field of view. However, in a configuration in which such packaged LED chips are arranged in a direct-type backlight unit 53, the emitted light from the LED chip is scattered. This is undesirable because the emitted light is diffused before it reaches the color filter provided in the pixel aperture, lowering the contrast. In other words, it becomes difficult to obtain a sufficient effect when applying local dimming.

[0016] Both the diffusion plate 55 and the wavelength conversion sheet 56 diffuse light. For example, the light emitted from a c-LED (blue LED) located directly below a c pixel is incident not only on the c pixel but also on the neighboring pixels a, b, d, e, f, etc., further reducing the effect of local dimming.

[0017] This is not limited to liquid crystal display devices, but also applies to LED displays known as micro LEDs, where the problem of reduced contrast due to light scattering or stray light into adjacent pixels has yet to be solved.

[0018] Unlike organic electroluminescence (EL), LEDs have high luminous efficiency and good heat resistance, so the amount of current applied to the LED element can be increased to obtain high luminance. Display devices that use LEDs as a light source can obtain brightness several to ten times greater than that of display devices that use organic electroluminescence (EL) as a light source. However, a new issue has arisen in that the components adjacent to the LED deteriorate due to heat generation near the LED element caused by the increase in the amount of current applied.

[0019] Patent Document 1 discloses a technique for providing a light-reflective partition wall in order to effectively utilize light emitted from a light source such as an LED or an organic EL. However, the partition disclosed in Patent Document 1 is configured to reflect the fluorescence generated in the phosphor layer by the inclined surface of the partition, so that the degree to which the light emitted from the light source can be effectively utilized is limited. For example, Patent Document 1 does not state anything about reflecting the light before entering the phosphor layer toward the light source at the end surface on the light source side.

[0020] Patent Document 2 discloses a technique for providing a metal reflective layer in order to effectively utilize light emitted from a light source such as an LED. However, the metal reflective layer in Patent Document 2 is disposed on the light source side of the color conversion layer surrounded by the black matrix, facing the color conversion layer, so that the metal reflective layer reflects the light emitted from the color conversion layer upward, improving light efficiency. However, for the blue light emitted from the active layer, the metal reflective layer is provided for the purpose of blocking the progression of the blue light. For example, paragraph 0124 discloses a configuration in which the metal reflective layer includes "a first metal layer and a second metal layer provided on the upper part of the first metal layer and having a higher reflectance than the first metal layer." The first metal layer is disposed for the purpose of increasing the optical loss of the blue light from the active layer.

[0021] Thus, Patent Documents 1 and 2 do not disclose a light-reflective matrix layer that has the same shape as the black matrix layer and is in contact with and overlaps the black matrix layer, nor do they disclose a technology for improving brightness by using re-reflection of light between the light-reflective matrix layer and, for example, a metal reflective layer (light-reflective electrode) on the light source side.

[0022] The present invention has been made in consideration of the above-mentioned background technology and problems, and provides a display device and a wavelength conversion substrate that can improve the brightness of displays such as micro LEDs (LED displays), mini LEDs, and liquid crystal display devices, which require even higher definition. [Means for solving the problem]

[0023] a first black matrix layer disposed opposite the first substrate across the color filter and having a plurality of pixel openings formed therein, the pixel openings opening toward the color filter; a light-reflective matrix layer laminated on a surface of the first black matrix layer opposite the first substrate in an area excluding the plurality of pixel openings; a wavelength conversion layer disposed between the color filter and the light-reflective matrix layer so as to overlap with at least one of the plurality of pixel openings in a plan view seen from a direction from the first substrate toward the first black matrix layer along a normal to one surface of the first substrate in the thickness direction, the wavelength conversion layer converting a wavelength of light passing through the at least one of the plurality of pixel openings toward the color filter; a surface of the first black matrix layer facing the color filter and an entire surface of the wavelength conversion layer facing the color filter are flush with each other. It is a display device.

[0024] The display device according to the present invention may be a display device in which the light reflective matrix includes a metal thin film of aluminum or an aluminum alloy.

[0025] The display device according to the present invention may be a display device in which the light reflective matrix contains a metal thin film of silver or a silver alloy.

[0026] The display device according to the present invention may be a display device in which the light-reflective matrix layer includes a thin film of titanium or titanium nitride laminated on the first black matrix layer, and a thin metal film of aluminum or an aluminum alloy laminated on the thin film.

[0027] The display device according to the present invention may be a display device in which the light-reflective matrix layer includes a first conductive oxide thin film containing indium oxide, a metal thin film of silver or a silver alloy laminated on the first conductive oxide thin film, and a second conductive oxide thin film containing indium oxide laminated on the metal thin film.

[0028] The display device of the present invention may be a display device in which each of the plurality of LEDs is a blue-emitting LED, and the wavelength conversion layer includes red conversion particles that convert blue light to red light, and green conversion particles that convert blue light to green light.

[0029] The display device of the present invention can be a display device in which each of the plurality of LEDs is a blue-emitting LED, and the wavelength conversion layer includes, from the plurality of LEDs toward the color filter, a red conversion layer in which light scattering particles and red conversion particles are dispersed in a transparent resin, and a green conversion layer in which light scattering particles and green conversion particles are dispersed in a transparent resin, in that order.

[0030] The display device of the present invention can be a display device in which each of the plurality of LEDs is a blue-emitting LED, the wavelength conversion layer is divided into a red conversion layer in which light scattering particles and red conversion particles are dispersed in a transparent resin, and a green conversion layer in which light scattering particles and green conversion particles are dispersed in a transparent resin, and any of the red conversion layer, the green conversion layer, and the light scattering layer in which light scattering particles are dispersed in a transparent resin are disposed inside the plurality of pixel openings.

[0031] The display device of the present invention can be a display device in which each of the plurality of LEDs is an LED that emits purple to near-ultraviolet light, and the wavelength conversion layer includes red conversion particles that convert the purple to near-ultraviolet light into red light, green conversion particles that convert the purple to near-ultraviolet light into green light, and blue conversion particles that convert the purple to near-ultraviolet light into blue light.

[0032] The display device according to the present invention may be a display device further comprising a second black matrix layer between the first black matrix layer and the first substrate, the second black matrix layer having a plurality of openings each overlapping with the plurality of pixel openings when viewed in a plan view.

[0033] The display device according to the present invention may be a display device in which a transmittance adjusting layer is inserted between the first substrate and the wavelength conversion layer to regulate the transmission of external light.

[0034] The display device according to the present invention may be a display device in which the transmittance adjusting layer contains carbon.

[0035] The display device of the present invention can be a display device in which the second substrate includes thin film transistors that drive each of the plurality of LEDs, and the thin film transistors include a conductive portion made of any of silver, silver alloy, copper, and copper alloy, and conductive wiring in which the conductive portion is sandwiched between a conductive oxide.

[0036] The display device according to the present invention may be a display device in which a heat dissipation film is formed on a surface of the second substrate opposite to the surface facing the first substrate.

[0037] A wavelength conversion substrate according to a second aspect of the present invention includes a transparent first substrate, a color filter facing the first substrate, a first black matrix layer disposed facing the first substrate and having a plurality of pixel openings formed therein, the pixel openings being opened toward the color filter, a light-reflecting matrix layer laminated on a surface of the first black matrix layer opposite the first substrate in an area excluding the pixel openings, and a wavelength conversion layer disposed between the light-reflecting matrix layer and the color filter so as to overlap with at least one of the pixel openings in a plan view of the light-reflecting matrix layer seen from the first substrate, the wavelength conversion layer converting a wavelength of light passing through the at least one of the pixel openings toward the color filter. a surface of the first black matrix layer facing the color filter and an entire surface of the wavelength conversion layer facing the color filter are flush with each other. This is a wavelength conversion substrate. Effect of the Invention

[0038] According to the display device and wavelength conversion substrate of the present invention, it is possible to provide a display device and a wavelength conversion substrate capable of improving the brightness of display in display devices such as micro LEDs (LED displays), mini LEDs, and liquid crystal display devices, which require even higher definition. [Brief description of the drawings]

[0039] [Figure 1] 1 is a partial cross-sectional view of a display device according to a first embodiment of the present invention. [Diagram 2] FIG. 11 is a partial cross-sectional view of a display device according to a second embodiment of the present invention. [Diagram 3] FIG. 3 is an enlarged view of part F3 in FIG. [Figure 4] 3 is a first modification of the light-reflective matrix layer shown in FIG. [Diagram 5] 3 is a second modification of the light-reflective matrix layer shown in FIG. [Figure 6] FIG. 3 is an enlarged view of part F6 in FIG. [Figure 7] 1 is an example of a circuit diagram for driving a light-emitting element using a thin film transistor or the like. [Figure 8]3 is a partial plan view showing the shapes of an auxiliary conductor, a light-reflective matrix layer, and a first black matrix layer in a plan view in FIG. 2. [Figure 9] FIG. 11 is a partial cross-sectional view of a display device according to a third embodiment of the present invention. [Figure 10] FIG. 11 is a partial cross-sectional view of a display device according to a fourth embodiment of the present invention. [Figure 11] FIG. 1 is a schematic cross-sectional view of a conventional display device equipped with a direct-type backlight unit that uses blue LEDs as light-emitting elements. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0040] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the following description, the same or substantially the same functions and components are given the same reference numerals, and their description is omitted or simplified, or is described only when necessary. In each drawing, the dimensions and ratios of each component are appropriately changed from the actual ones in order to make each component large enough to be recognized on the drawing. In addition, as necessary, elements that are difficult to illustrate, such as the configuration of a thin film transistor, the structure of multiple layers constituting a conductive layer, wiring connections to a circuit section, switching elements (transistors), etc., are omitted or partially illustrated.

[0041] In each embodiment described below, characteristic features will be described, and descriptions of components that are the same as those used in a typical display device and the display device according to this embodiment will be omitted.

[0042] Ordinal numbers such as "first" and "second" in the first black matrix layer, second black matrix layer, first substrate, second substrate, third substrate, etc. are used to avoid confusion of components and do not limit the quantity. The matrix arrangement of light-emitting elements refers to an arrangement in which light-emitting units including one or more light-emitting elements (LEDs) are arranged in a matrix shape with a constant pitch in a plan view. Here, "arranged in a matrix shape" means that they are arranged at positions corresponding to the intersections of various two-dimensional lattices. For example, examples of two-dimensional lattices include square lattices, rectangular lattices, parallelogram lattices, oblique lattices (diamond lattices), and triangular lattices. "Constant pitch" means that the pitch along one direction of the lattice is constant, and the pitches in two different directions may be different from each other. For example, a square lattice is an example of a lattice having equal pitches in two mutually perpendicular directions, and a rectangular lattice other than a square lattice is an example of a lattice having constant pitches that are different from each other in two mutually perpendicular directions. For example, a triangular lattice is not limited to a regular triangular lattice, and includes a scalene triangular lattice. In the following description, a substrate on which light-emitting elements are arranged in a matrix, or a substrate on which light-emitting units are arranged in a matrix at a fixed pitch, may be referred to as an optical module. Thin film transistors that drive the light-emitting elements or light-emitting units are preferably also arranged on the substrate. When the display function layer is a liquid crystal layer, this optical module is called a direct type backlight. The light emitting unit may be surrounded by a partition wall having a grid pattern in a plan view when the display device is assembled.

[0043] The term "planar view" in the specification means, unless otherwise specified, a "planar view" in which a first substrate is viewed from a first substrate toward a second substrate, which will be described later, along a normal line of one surface of the first substrate, which will be described later. This planar view direction also coincides with the direction in which a first black matrix layer, which will be described later, is viewed from the first substrate.

[0044] In an embodiment of the present invention, a plurality of light-emitting diode elements called LEDs (Light Emitting Diodes) can be used in the "display function layer" of the display device. The LED chip and light-emitting diode element refer to LEDs, and may be simply referred to as light-emitting elements in the following description.

[0045] LEDs use compounds such as aluminum gallium arsenide (AlGaAs), gallium arsenide phosphide (GaAsP), indium gallium nitride (InGaN) / gallium nitride (GaN) / aluminum gallium nitride (AlGaN), gallium phosphide (GaP), zinc selenide (ZnSe), and aluminum indium gallium phosphide (AlGaInP). Monochromatic LEDs such as blue LEDs and near-ultraviolet LEDs, which will be described later, mainly use gallium nitride (GaN).

[0046] In an embodiment of the present invention, blue refers to light having a wavelength in the range of 410 nm or more and less than 490 nm. A blue LED (a blue-emitting LED) is an LED having an emission peak in the wavelength range of 410 nm or more and less than 490 nm. In an embodiment of the present invention, near-ultraviolet light refers to light having a wavelength in the range of 300 nm or more and less than 410 nm (emission of purple to near-ultraviolet light). A near-ultraviolet LED is an LED having an emission peak in the wavelength range of 300 nm or more and less than 410 nm. In an embodiment of the present invention, the monochromatic light emitting LED is an LED having a half-width of 70 nm or less and one emission peak within the above wavelength range. The smaller the half-width, the more preferable.

[0047] Mini LEDs can use LED chips with sizes of, for example, 50 μm to 200 μm. Micro LEDs can use LED chips with sizes of, for example, 2 μm to 50 μm. The LED chip structure can be a horizontal LED in which the n-side electrode and the p-side electrode are on the same side, or a vertical LED in which the n-side electrode and the p-side electrode are on different surfaces (facing parallel surfaces) in the thickness direction of the LED. In the following description, the upper electrode and the lower electrode refer to either the n-side electrode or the p-side electrode of a vertical LED.

[0048] [First embodiment] A display device and a wavelength conversion substrate according to a first embodiment will be described. FIG. 1 is a partial cross-sectional view of a display device according to a first embodiment of the present invention. A display device 100 shown in FIG. 1 is an example of the display device according to this embodiment. The display device 100 includes a first substrate 110 and a second substrate 120. Between the first substrate 110 and the second substrate 120, a color filter 2, a first black matrix layer 1, a light reflective matrix layer 6, a wavelength conversion layer 3, and a plurality of light emitting elements 24 (LEDs) are arranged.

[0049] [First board] The first substrate 110 is a transparent substrate through which display light emitted from the display device 100 passes toward the viewer 59. The first substrate 110 is a flat plate having a surface 110a (one surface) and a surface 110b in the thickness direction. The surface 110a faces the viewer 59 and is the plane from which the display light is emitted from the first substrate 110. Surface 110a may form the outermost surface of display device 100, or may be covered with an appropriate light-transmitting layer or member. In the example shown in Fig. 1, a circular polarizer 11 is disposed on surface 110a. The surface 110b is the surface opposite to the surface 110a, and is a plane through which display light enters the first substrate 110.

[0050] Circular polarizer 11 is formed by combining a linear polarizer and a quarter-wave plate, and converts a certain linearly polarized component into circularly polarized light. Therefore, when circular polarizer 11 is disposed on surface 110a, it is possible to suppress the emission to the outside of a part of polarized light, such as external light, that is incident on display device 100 and internally reflected. However, if the reflected light of external light can be reduced to a necessary range by the transmittance adjusting layer 7 described later, the circular polarizer 11 can be omitted.

[0051] The material of the first substrate 110 may be, for example, a transparent substrate such as a glass substrate, a quartz substrate, a sapphire substrate, or a plastic substrate including a polyimide film. The higher the visible light transmittance of the first substrate 110, the more preferable it is. For example, the transmittance of the first substrate 110 may be 50% or more and 100% or less, and is more preferably 90% or more and 100% or less.

[0052] In the following, two axes that are perpendicular to each other on a plane parallel to the surface 110a are referred to as the x-axis and the y-axis. The positive direction of the x-axis (hereinafter, the positive x-axis direction) is the direction from left to right in Fig. 1. The positive direction of the y-axis (hereinafter, the positive y-axis direction) is the direction from the back to the front in Fig. 1. The axis perpendicular to the x-axis and y-axis is called the z-axis. The z-axis is a normal line to the surface 110a. The positive direction of the z-axis (hereinafter, the z-axis positive direction) is the direction from the surface 110a to the surface 110b, and coincides with the direction indicated by the arrow P in the plan view. In the following, based on the arrangement in Figure 1, a position relatively in the positive direction of the z axis from a specific position may be referred to as being below, positioned downward, etc., and a position relatively in the negative direction of the z axis may be referred to as being above, positioned upward, etc. The direction along the x-axis may be referred to as the x-axis direction, the direction along the y-axis as the y-axis direction, and the direction along the z-axis as the z-axis direction.

[0053] [Second board] The second substrate 120 is a flat plate disposed below the first substrate 110 (in the positive direction of the z-axis) and spaced apart from the first substrate 110. The second substrate 120 has an upper surface 120a facing the first substrate 110 and a lower surface 120b opposite to the upper surface 120a. The upper surface 120a and the lower surface 120b are parallel to the surface 110a of the first substrate 110. Above the second substrate 120 (in the negative direction of the z-axis), a plurality of light-emitting elements 24 are arranged in a matrix in plan view. The material of the second substrate 120 may be the same as or different from the material of the first substrate 110. In particular, the second substrate 120 does not need to be transparent and may be, for example, a substrate colored black, white, or another color. For example, the second substrate 120 may be a sifer substrate, or a silicon substrate on which CMOS elements (transistors, etc.) are arranged. The second substrate 120 may be a silicon substrate on which the light-emitting elements 24 are formed by crystal-grown LEDs via a buffer layer.

[0054] An LED is used as the light emitting element 24. It is more preferable that the LED used for the light emitting element 24 is a monochromatic LED. As the monochromatic LED, a blue LED or a near-ultraviolet LED is particularly preferable. There is no particular limitation on the method for mounting the light-emitting element 24. For example, the method for mounting the light-emitting element 24 may include flip-chip mounting using a low-melting-point alloy, mounting using an anisotropic conductive film, or wire bonding using a gold wire or the like.

[0055] A plurality of thin film transistors for driving the light emitting elements 24 may be disposed on the second substrate 120. When the display device 100 includes a liquid crystal layer, the plurality of thin film transistors may drive the liquid crystal layer.

[0056] 1, a third insulating layer 36, a second insulating layer 35, and a first insulating layer 34 are laminated in this order on an upper surface 120a of the second substrate 120. Thin film transistors that drive each light-emitting element 24 are formed in the third insulating layer 36, the second insulating layer 35, and the first insulating layer 34 by a semiconductor manufacturing process.

[0057] In the example shown in FIG. 1, the light emitting element 24 is an LED formed by laminating a second semiconductor layer 27, a light emitting layer 26, and a first semiconductor layer 25 in this order in the negative direction of the z axis. The light emitting element 24 is laminated on a reflective electrode 29 formed on the upper surface of the first insulating layer 34 with a lower electrode 28 interposed therebetween. The lower electrode 28 is an electrode that applies a driving voltage to the light-emitting layer 26 of each light-emitting element 24 . The reflective electrode 29 is an electrode made of a metal with high reflectivity, which is electrically connected to the lower electrode 28 and reflects light traveling in the positive direction of the z axis from the light emitting layer 26 in the negative direction of the z axis. Each light emitting element 24 is electrically connected to a thin film transistor (not shown) through, for example, a lower electrode 28, a reflective electrode 29, a contact hole 32, and the like.

[0058] 1, partition walls 37 are provided around the light emitting elements 24 to prevent color mixing with adjacent light emitting elements 24 and to surround the light emitting elements 24 in order to extract light from the side surfaces to the upper part. That is, the partition walls 37 are arranged in a rectangular lattice shape that sandwiches the light emitting elements 24 arranged in a matrix shape in the x-axis direction and the y-axis direction in a plan view. The partition walls 37 are formed so as to be covered with a first black matrix layer 1 described later in a plan view. The partition 37 may be a light-reflecting partition in which the surface of a wall formed of a photoresist is covered with a thin metal film having a high reflectivity, such as aluminum or silver. The partition 37 may have a light-scattering property. When a metal thin film is used for the partition walls 37, the same metal thin film as that of the light-reflective matrix layer 6 described later may be used.

[0059] An upper electrode 23 is laminated on the upper side of the light emitting element 24 and the partition wall 37 as a common electrode in the display device 100. The upper electrode 23 has optical transparency that transmits light from the light emitting element 24. For example, the upper electrode 23 can be formed of a transparent conductive film such as ITO (indium tin oxide). The light emitting element 24 emits light based on a voltage applied between the lower electrode 28 and the upper electrode 23 .

[0060] An auxiliary conductor 31 is laminated on the upper electrode 23 at a position overlapping with the partition wall 37 in a plan view. The auxiliary conductor 31 is provided for the purpose of dissipating heat generated in the light emitting element 24 and conducted to the upper electrode 23. The configuration of the auxiliary conductor 31 is not particularly limited as long as it can efficiently conduct heat from the upper electrode 23. For example, the auxiliary conductor 31 may be formed in a three-layer structure in which a metal is sandwiched between conductive oxides. It is more preferable that the metal used for the auxiliary conductor 31 is a metal with high thermal conductivity. For example, examples of metals suitable for the auxiliary conductor 31 include silver, silver alloys, aluminum, and aluminum alloys. The thicker the metal used for the auxiliary conductor 31 is in the z-axis direction, the more efficiently heat can be dissipated from the light emitting element 24 .

[0061] The lower surface 120b of the lower side of the second substrate 120 may form the outermost surface of the display device 100, or may be covered with an appropriate layer film or member. In the example shown in FIG. 1, a heat dissipation film 10 for promoting heat dissipation from the display device 100 is laminated on the lower surface 120b. There are no particular limitations on the material of the heat dissipation film 10 as long as it has good heat dissipation properties. For example, the heat dissipation film 10 may be a thin film made of aluminum or copper formed on the lower surface 120b by vapor deposition or sputtering.

[0062] Since the auxiliary conductor 31 and the heat dissipation film 10 are provided for dissipating heat from the light emitting element 24, at least one of the auxiliary conductor 31 and the heat dissipation film 10 can be omitted depending on the amount of heat generated by the light emitting element 24. For example, when the luminance of the light-emitting element 24 is 300 cd / m 2 In the above cases, it is more preferable that at least one of the auxiliary conductor 31 and the heat dissipation film 10 is provided.

[0063] A transparent resin adhesive layer 9 is laminated on the upper surfaces of the upper electrode 23 and the auxiliary conductor 31 . The transparent resin adhesive layer 9 is a layer portion that bonds the upper electrode 23 and the auxiliary conductor 31 to the light-reflective matrix layer 6 described below. The transparent resin adhesive layer 9 is formed from a cured product of a transparent resin adhesive. For example, the material for forming the transparent resin adhesive layer 9 may be a silicone-based adhesive resin, an epoxy-based adhesive resin, a urethane-based adhesive resin, or the like.

[0064] On the upper surface of the transparent resin adhesive layer 9, a light reflective matrix layer 6 and a first black matrix layer 1 are laminated in this order.

[0065] [First black matrix layer] The first black matrix layer 1 is made of a light absorbing material to prevent color mixture of display light, and has a plurality of pixel openings Or, Og, and Ob penetrating therethrough in the layer thickness direction. The pixel openings Or, Og, Ob are all rectangular in plan view, and the center of each of the pixel openings Or, Og, Ob in plan view overlaps with the light emitting center of each light emitting element 24 in plan view. The pixel opening Or faces the light emitting element 24 that emits light corresponding to red display light. The pixel opening Og faces the light emitting element 24 that emits light corresponding to green display light. The pixel opening Ob faces the light emitting element 24 that emits light corresponding to blue display light. Furthermore, the pixel openings Or, Og, and Ob open toward a red filter R, a green filter G, and a blue filter B, respectively, which will be described later.

[0066] In Fig. 1, the pixel openings Or, Og, and Ob are repeatedly arranged in this order in the positive direction of the x-axis. In the y-axis direction, other pixel openings Or, Og, and Ob are arranged in correspondence with the pixel openings Or, Og, and Ob shown in Fig. 1, respectively. Therefore, the multiple pixel openings Or, Og, and Ob are arranged in a striped pattern with spaces between each other in the y-axis direction. However, the arrangement of the pixel openings Or, Og, Ob is not limited to this, and an appropriate arrangement can be selected from well-known arrangements of red pixels, green pixels, and blue pixels in a display device. 1 shows an example in which the inner peripheral surfaces of the pixel openings Or, Og, and Ob extend in the z-axis direction, but the inner peripheral surfaces of the pixel openings Or, Og, and Ob may be inclined with respect to the z-axis. The inclination direction of each inner peripheral surface is not particularly limited. For example, from the viewpoint of the light utilization efficiency of the light emitting element 24, when each inner peripheral surface is inclined, it is more preferable that the inclination be such that the opening area increases as it progresses in the negative direction of the z-axis.

[0067] The first black matrix layer 1 can be formed by dispersing a black pigment having a visible light absorbing function, such as carbon, in a resin. In this embodiment, since the light-reflective matrix layer 6 described later is laminated on the surface of the first black matrix layer 1 in the negative z-axis direction, a very high light-shielding property is not required. The light blocking ability of the first black matrix layer 1 is sufficient when its optical density OD is in the range of 2 or more and less than 4, for example. There is no particular limitation on the thickness of the first black matrix layer 1 as long as the necessary light-shielding properties are obtained. For example, the thickness of the first black matrix layer 1 may be 1 μm or more and 50 μm or less. By setting the concentration of the black color material to a low level, the thickness of the first black matrix layer 1 can be set to, for example, 10 μm or more. The first black matrix layer 1 having a thickness of 10 μm or more is more preferable because it can be formed to match the thickness required for the wavelength conversion layer 3 described later. The optical density of the first black matrix layer 1 may be 4 or more, but this increases the process load such as exposure time. If the optical density is 1 or less, external light is reflected by a metal thin film or the like inside the display device 100 and is easily visible to the observer 59, which may lead to a deterioration in image quality of the display device 100. The concentration of the black color material in the first black matrix layer 1 and the layer thickness of the first black matrix layer 1 can be set appropriately so as to obtain the above-mentioned range of optical density.

[0068] As the black color material, in addition to carbon, carbon fiber, carbon nanotube, carbon nanohorn, carbon nanobrush, etc. can be used. As long as the necessary light-shielding properties are obtained, the color material used in the first black matrix layer 1 is not limited to a black color material. For example, in addition to the black color material, an organic pigment such as a blue pigment may be added. For example, the first black matrix layer 1 may contain a metal oxide such as titanium black.

[0069] [Light-reflective matrix layer] The light-reflective matrix layer 6 is formed of a light-reflective thin film, and is laminated from below on the lower surface 1b, which is the surface of the first black matrix layer 1 opposite to the first substrate 110 (positive direction of the z-axis). The planar shape of the light-reflective matrix layer 6 may be such that it covers at least a part of the lower surface 1b. That is, the light-reflective matrix layer 6 may be laminated on the lower surface 1b in an area excluding the pixel openings Or, Og, and Ob. It is more preferable that the light-reflective matrix layer 6 has the same shape as the lower surface 1b and covers the entire lower surface 1b. 1, the light-reflective matrix layer 6 is laminated in the same shape as the lower surface 1b of the first black matrix layer 1 over the entire lower surface 1b of the first black matrix layer 1. Therefore, the light-reflective matrix layer 6 has a rectangular lattice pattern in a plan view similar to that of the first black matrix layer 1.

[0070] The material of the light-reflective matrix layer 6 is not particularly limited as long as it can efficiently reflect the light emitted from the light-emitting element 24. For example, the light-reflective matrix layer 6 may be formed of a metal thin film of any one of aluminum, an aluminum alloy, silver, and a silver alloy. The film thickness of the light-reflective matrix layer 6 may be, for example, 0.1 μm or more and 0.8 μm or less. When the thickness of the light-reflective matrix layer 6 is 0.1 μm or more, high light blocking properties and high reflectance can be obtained, and therefore the light emitted from the light-emitting element 24 can be reflected downward and efficiently reused. The upper limit of the film thickness of the light-reflective matrix layer 6 is not particularly limited, but may be 0.8 μm or less, for example, when there is concern that an increase in the film thickness of the metal thin film may cause warping of the substrate.

[0071] The aluminum alloy used for the light-reflective matrix layer 6 may be an aluminum alloy containing a small amount of a high melting point metal such as Mo or Ti, Si, or a rare earth such as Nd (neodymium). From the viewpoint of reflectance, an aluminum alloy containing 0.2% by mass or more and 3% by mass or less of Nd is more preferable. If the Nd content is less than 0.2% by mass, the aluminum crystals tend to become coarse and hillocks tend to form, which tends to reduce the reflectance. If the Nd content exceeds 3% by mass, the reflectance tends to decrease. If the Nd content is in the range of 0.2% by mass or more and 3% by mass or less, a high reflectance is easily reproduced stably.

[0072] In order to improve the adhesion of the light-reflective matrix layer 6 to the first black matrix layer 1, an intermediate layer may be provided between the light-reflective thin film and the first black matrix layer 1. For example, when the light-reflective thin film is a metal thin film of aluminum or an aluminum alloy, the intermediate layer is particularly preferably made of titanium, molybdenum, or nitrides of these high-melting point metals.

[0073] When a metal thin film of silver or a silver alloy is used as the light-reflective matrix layer 6, it is particularly preferable to use a configuration in which the metal thin film is sandwiched between conductive oxides containing indium oxide, zinc oxide, or the like, because silver and silver alloys have low adhesion to the first black matrix layer 1. Since silver atoms are easily diffused, when silver or a silver alloy is used, it is more preferable to add a different metal such as copper, gold, palladium, or zinc in the range of 0.1% by mass to 1.5% by mass.

[0074] The light-reflective matrix layer 6 has a role of preventing the light emitted from the light-emitting element 24 from being absorbed by the first black matrix layer 1, and returning the emitted light to the light-emitting element 24 side. The returned emitted light is reflected by a light-reflective member located closer to the second substrate 120 than the light-reflective matrix layer 6. This allows at least a part of the returned emitted light to be reused, improving the brightness of the display light of the display device 100. Specifically, the emitted light reflected by the light-reflective matrix layer 6 toward the outside of the pixel opening is reflected by the lower part of the light-emitting element 24, the light-reflective electrode around the light-emitting element 24, the partition wall 37, and the light-reflective matrix layer 6, and re-enters the pixel opening, improving the brightness. 1 shows a schematic diagram of optical paths L1, L2, L2, L3, and L4 of light emitted from a side surface of the light-emitting element 24 facing the pixel opening Ob. Light (L1) from the side surface of the light-emitting element 24 is reflected by the partition wall 37 surrounding the light-emitting element 24, emitted upward (L2), reflected again by the light-reflective matrix layer 6 (L3), reflected again by the reflective electrode 29 below the light-emitting element 24 (L4), and enters the pixel opening Ob. The reflected light that enters the pixel opening Ob is utilized as display light for the display device 100, together with the emitted light that directly enters the pixel opening Ob from the light-emitting element 24. In contrast, if the light-reflective matrix layer 6 is not formed adjacent to the pixel opening Ob, the light traveling along the optical path L1 enters the first black matrix layer 1 and is absorbed by the first black matrix layer 1.

[0075] When the light-reflective matrix layer 6 has a metal thin film, the heat conductivity of the light-reflective matrix layer 6 is higher than that of the first black matrix layer 1. This promotes heat dissipation around the light-emitting element 24 through the light-reflective matrix layer 6.

[0076] [Wavelength conversion layer] The wavelength conversion layer 3 is a layer portion that converts the wavelength of the light emitted from the light emitting element 24 . Here, wavelength conversion refers to the process of receiving primary light emitted from a light-emitting element such as an LED or organic EL, and converting the primary light into secondary light having a different wavelength in the visible light range. The most common wavelength conversion method is down-conversion, which converts short wavelengths such as blue or near-ultraviolet light into long wavelengths such as blue, green, or red.

[0077] Materials used for wavelength conversion can be divided into two categories: quantum dots, which are nanometer-sized semiconductor particles with a quantum confinement effect (hereafter referred to as quantum dots), and inorganic phosphors (hereafter referred to as phosphors), which are represented by complex oxides and nitrides to which activators such as rare earth elements such as EU (europium), Ce (cerium), and Y (yttrium) have been added.

[0078] Compared to quantum dots, phosphors have a larger average particle size of 0.5 to 30 μm, but they are highly reliable in terms of heat resistance, light resistance, etc., as they are manufactured under high temperature and pressure.

[0079] Examples of quantum dots include II-VI group semiconductor compounds such as MgS, MgSe, MgTe, CaS, CaSe, CaTe, SrS, SrSe, SrTe, BaS, BaSe, BaTe, ZnS, ZnSe, ZnTe, CdS, CdSe, CdTe, HgS, HgSe, and HgTe, IIIV group semiconductor compounds such as AlN, AlP, AlAs, AlSb, GaAs, GaP, GaN, GaSb, InN, InAs, InP, InSb, TiN, TiP, TiAs, and TiSb, and semiconductor crystals containing IV group semiconductors such as Si, Ge, and Pb, as well as semiconductor compounds containing three or more elements such as InGaP. The size of the quantum dots is, for example, within the range of 0.5 nm to 30 nm, and the converted light shifts to the long wavelength side by increasing the particle size.

[0080] The wavelength conversion layer 3 may contain red conversion particles, green conversion particles, and blue conversion particles to obtain red, green, and blue secondary lights. The red conversion particles, green conversion particles, and blue conversion particles applicable to the wavelength conversion layer 3 may be appropriately selected from quantum dots or phosphors. Hereinafter, any or all of the red conversion particles, green conversion particles, and blue conversion particles may be referred to as conversion particles. The red conversion particles refer to phosphor or quantum dot particles that can receive blue light, violet light, or near-ultraviolet light and convert it to red wavelengths. The green conversion particles and blue conversion particles refer to phosphor or quantum dot particles that can receive blue light or near-ultraviolet light and convert it to green light and blue light, respectively.

[0081] The wavelength conversion layer 3 may be configured such that a plurality of types of layers containing different conversion particles are arranged apart from each other or adjacent to each other in plan view. The wavelength conversion layer 3 may have a configuration in which multiple types of layers each containing multiple types of conversion particles are stacked. In this case, it is more preferable to arrange the long wavelength conversion particles, for example, red conversion particles, closer to the light emitting element 24. It is more preferable to arrange the conversion particles that convert light into light with a shorter wavelength than red, such as green conversion particles and blue conversion particles, farther from the light emitting element 24 than the red conversion particles.

[0082] When the light emitting element 24 emits blue light, the wavelength conversion layer 3 for converting blue light to blue may be omitted. In this case, a light scattering layer for scattering light may be provided instead of the wavelength conversion layer 3. When the light emitting element 24 emits near-ultraviolet light, the wavelength conversion layer 3 is more preferably provided with a red conversion layer, a green conversion layer and a blue conversion layer containing red conversion particles, green conversion particles and blue conversion particles, respectively.

[0083] The wavelength conversion layer 3 may be formed as a dispersion in which conversion particles are dispersed in a resin 15 having excellent heat resistance and light resistance. Examples of the resin 15 used in the dispersion include silicone resin, epoxy resin, phenol resin, polycarbonate resin, acrylic resin, polynorbornene resin, modified resins thereof, hybrid resins, etc. With these resins, a liquid dispersion is formed as a liquid resin using a monomer or an organic solvent, and then the dispersion is applied and cured by an apparatus such as a spin coater, a slit coater, a curtain coater, or an inkjet to form the wavelength conversion layer 3. When a phosphor is used as the conversion particles, for example, the conversion particles can be formed by applying a dispersion liquid (dispersion) in which the phosphor is dispersed in an alkali-soluble photosensitive polymer resist, and patterning the dispersion liquid by a photolithography technique as necessary. The wavelength conversion layer 3 may be formed by directly forming a dispersion on the surface of the first substrate 110 or the second substrate 120 using a printing technique.

[0084] As in the example shown in FIG. 1, the wavelength conversion layer 3 may contain, for example, transparent light scattering particles 17 mixed in addition to the wavelength conversion material such as the quantum dots and phosphors described above. For example, transparent particles having an average particle size of 1.0 μm or more and 3.0 μm or less can be used as the light scattering particles 17. By using particles having a particle size larger than the wavelength of visible light as the light scattering particles 17, appropriate light scattering properties can be easily obtained. Furthermore, the wavelength conversion layer 3 may contain transparent fine particles having an average particle size of 0.05 μm or more and 0.3 μm or less as a dispersion aid for promoting dispersion of the light scattering particles 17.

[0085] Optically isotropic transparent particles can be used for the light scattering particles 17. "Optically isotropic" means that the transparent particles applied to the embodiment of the present invention have a crystal structure in which the a-axis, b-axis, and c-axis are equal to each other, or are amorphous, and the propagation of light is isotropic and not affected by the crystal axis or crystal structure. For example, silica particles have a non-crystalline structure (amorphous). Resin particles such as resin beads are known to have various properties including refractive index. Optically isotropic resin particles such as resin beads can be used in combination with silica particles as light scattering particles 17. For example, resin particles such as acrylic, styrene, urethane, nylon, melamine, and benzoguanamine can be used in combination with silica particles.

[0086] If the light scattering particles 17 are optically isotropic transparent particles, then when the display device 100 includes a circular polarizer or a polarizing plate, unevenness in light loss is less likely to occur. In a display device that does not require the use of a circular polarizer or a polarizing plate, since there is no unevenness in the amount of light due to polarization, the transparent particles do not need to be optically isotropic. This allows a wider range of transparent particles to be selected. For example, zinc oxide particles can be used as transparent particles that can be added to the wavelength conversion layer 3. Zinc oxide has high transmittance in the visible range of wavelengths from 400 nm to 700 nm and can absorb ultraviolet rays of 390 nm or less. From this perspective, in a display device that does not use a circular polarizer, it is more preferable to use, for example, transparent particles or transparent fine particles of zinc oxide as the light scattering particles 17.

[0087] The thickness of the wavelength conversion layer 3 can be from 1 μm to 50 μm. It can be made thicker than 50 μm, but making it thicker increases the process load, for example, the time required for coating and drying is likely to be wasted. If the thickness of the wavelength conversion layer 3 is from 1 μm to 50 μm, the film thickness of the first black matrix layer 1 can be adjusted to the thickness of the wavelength conversion layer 3.

[0088] In the example shown in FIG. 1, the wavelength conversion layer 3 includes a red conversion layer 3R and a green conversion layer 3G formed in the pixel openings Or and Og, respectively. The red color conversion layer 3R has red color conversion particles 12 and light scattering particles 17, which are optically isotropic transparent particles, dispersed in a resin 15. The green color conversion layer 3G has green color conversion particles 13 and light scattering particles 17, which are optically isotropic transparent particles, dispersed in a resin 15. In the example shown in FIG. 1, the light-emitting element 24 facing the pixel opening Ob is a blue LED, and therefore a light-scattering layer 3B that scatters the light emitted from the blue LED without converting the wavelength of the light is formed in the pixel opening Ob. The red conversion layer 3R, the green conversion layer 3G, and the light scattering layer 3B are formed inside the pixel openings Or, Og, and Ob, respectively, to the same layer thickness as the total thickness of the first black matrix layer 1 and the light reflective matrix layer 6. Therefore, the upper surfaces of the red conversion layer 3R, the green conversion layer 3G, and the light scattering layer 3B are flush with the upper surface 1a, which is the surface of the first black matrix layer 1 on the first substrate 110 side (z-axis negative direction). The red conversion layer 3R and the green conversion layer 3G shown in FIG. 1 are examples of wavelength conversion layers 3 that are arranged apart from each other in a plan view.

[0089] [Light scattering layer] Here, the light scattering layer 3B will be described. The light scattering layer 3B is formed in the same manner as the red conversion layer 3R and the green conversion layer 3G, except that the light scattering layer 3B does not contain conversion particles. That is, the light scattering layer 3B is formed by dispersing light scattering particles 17 in a transparent resin similar to that of the red conversion layer 3R and the green conversion layer 3G. The light scattering layer 3B may contain a dispersion aid similar to that of the red conversion layer 3R and the green conversion layer 3G. In the example shown in FIG. 1, the light scattering particles 17 contained in the light scattering layer 3B are optically isotropic transparent particles.

[0090] [Color Filter] The color filter 2 is disposed between the wavelength conversion layer 3 and the first substrate 110, and faces the first substrate 110. The color filter 2 restricts the wavelength range of light emitted from the wavelength conversion layer 3 toward the first substrate 110. For example, the color filter 2 includes a red filter R that restricts the transmitted light to a red wavelength range, a green filter G that restricts the transmitted light to a green wavelength range, and a blue filter B that restricts the transmitted light to a blue wavelength range. The red filter R is disposed between the pixel opening Or and the first substrate 110. The green filter G is disposed between the pixel opening Og and the first substrate 110. The blue filter B is disposed between the pixel opening Ob and the first substrate 110. The red filter R, the green filter G, and the blue filter B may be separate from each other or adjacent to each other.

[0091] 1, the color filters 2 are adjacent to each other on the upper surface 1a of the first black matrix layer 1. Therefore, the color filters 2 are formed in a layer shape covering the first black matrix layer 1, the wavelength conversion layer 3, and the light scattering layer 3B as a whole. In the example shown in FIG. 1, the upper surface of the color filter 2 is laminated on the first substrate 110 with a transmittance adjustment layer 7, which will be described later, sandwiched therebetween. The color filter 2 may be formed by being laminated on a laminate including the first substrate 110 and the transmittance adjustment layer 7, or may be formed by being laminated on the first black matrix layer 1, the wavelength conversion layer 3, and the light scattering layer 3B which are laminated on the first substrate 110.

[0092] The color filter 2 can be formed by dispersing an organic pigment in a transparent resin such as acrylic. Examples of red organic pigments that can be used for the red filter R include CI Pigment Red 7, 14, 41, 48:2, 48:3, 48:4, 81:1, 81:2, 81:3, 81:4, 146, 168, 177, 178, 179, 184, 185, 187, 200, 202, 208, 210, 246, 254, 255, 264, 270, 272, and 279. In addition to the red pigment, the red filter R can also contain a yellow pigment or an orange pigment.

[0093] For example, examples of yellow organic pigments that can be applied to the color filter 2 include CI Pigment Yellow 1, 2, 3, 4, 5, 6, 10, 12, 13, 14, 15, 16, 17, 18, 24, 31, 32, 34, 35, 35:1, 36, 36:1, 37, 37:1, 40, 42, 43, 53, 55, 60, 61, 62, 63, 65, 73, 74, 77, 81, 83, 93, 94, 95, 97, 98, 100, 101, 104, 106, 108, 109, 110, 113, 114, 115, 116, 1 17, 118, 119, 120, 123, 126, 127, 128, 129, 147, 151, 152, 153, 154, 155, 156, 161, 162, 164, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176, 177, 179, 180, 181, 182, 187, 188, 193, 194, 199, 198, 213, 214, etc.

[0094] Examples of green organic pigments that can be used for the green filter G include green pigments such as CI Pigment Green 7, 10, 36, and 37. Furthermore, for the green filter G, a halogenated zinc phthalocyanine green pigment or a halogenated aluminum phthalocyanine green pigment can also be suitably used. The green filter G may contain the above-mentioned yellow pigment in addition to the green pigment.

[0095] Examples of blue organic pigments that can be used for the blue filter B include blue pigments such as CI Pigment Blue 15, 15:1, 15:2, 15:3, 15:4, 15:6, 16, 22, 60, and 64. In addition to the blue pigment, a violet pigment can also be used in combination with the blue filter B. Examples of the violet pigment include CI Pigment Violet 1, 19, 23, 27, 29, 30, 32, 37, 40, 42, and 50.

[0096] These organic pigments are used by dispersing them in a transparent resin together with an organic solvent and a dispersant. The transparent resin is preferably a transparent resin having a visible transmittance of 90% or more, and more preferably an alkali-soluble photosensitive resin containing a resin precursor. When producing the color filter 2, the organic pigment can be contained in the transparent resin in a range of 15% by mass to 60% by mass.

[0097] Examples of photosensitive resins suitable for the color filter 2 include resins in which a linear polymer having a reactive substituent such as a hydroxyl group, a carboxyl group, or an amino group is reacted with a (meth)acrylic compound or cinnamic acid having a reactive substituent such as an isocyanate group, an aldehyde group, or an epoxy group to introduce a photocrosslinkable group such as a (meth)acryloyl group or a styryl group into the linear polymer.

[0098] Examples of monomers and oligomers that are precursors of transparent resins suitable for the color filter 2 include various acrylic acid esters and methacrylic acid esters such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, cyclohexyl (meth)acrylate, polyethylene glycol di(meth)acrylate, pentaerythritol tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, tricyclodecanyl (meth)acrylate, melamine (meth)acrylate, and epoxy (meth)acrylate, (meth)acrylic acid, styrene, vinyl acetate, (meth)acrylamide, N-hydroxymethyl (meth)acrylamide, and acrylonitrile. These can be used alone or in combination of two or more. When the transparent resin having the organic pigment dispersed therein is cured by irradiation with ultraviolet light having a wavelength of, for example, 365 nm, a photopolymerization initiator and the like are further added.

[0099] [Transmittance adjustment layer] The transmittance adjusting layer 7 is a layer portion that adjusts the transmittance of reflected light from the display device 100 of external light incident on the display device 100 in order to improve visibility. The transmittance adjusting layer 7 has a role of reducing the combined reflectance of the surface layer portion and the inside of the display device 100 by reducing the transmittance of reflected light from the surface layer portion and the inside of the display device 100 to the outside. The transmittance adjusting layer 7 is disposed between the first substrate 110 and the wavelength conversion layer 3. However, it is more preferable that the transmittance adjusting layer 7 be disposed close to the first substrate 110 so as to suppress various reflected lights from inside the display device 100. By providing the transmittance adjusting layer 7, external light reflection at the light reflective member on the z-axis positive side of the transmittance adjusting layer 7 can be suppressed, and the visibility of the display screen of the display device 100 for the observer 59 can be improved. In the example shown in FIG. 1, the transmittance adjusting layer 7 is laminated on the surface 110b of the first substrate 110. In this case, examples of light reflective members on the positive side of the z-axis from the transmittance adjusting layer 7 include the wavelength conversion layer 3, the reflective electrode 29, and the light emitting element 24 when not lit. In addition, since the transmittance adjusting layer 7 is disposed closer to the first substrate 110 than the first black matrix layer 1, it is possible to reduce reflected light from the reflective surface of the first black matrix layer 1. Therefore, even when a reflective surface is formed on the surface of the first black matrix layer 1 facing the first substrate 110, it is possible to suppress reflection of external light in the first black matrix layer 1.

[0100] The configuration of the transmittance adjusting layer 7 is not particularly limited as long as it can regulate the transmittance of the visible light component contained in the external light. For example, the transmittance adjusting layer 7 may be a resin dispersion in which at least carbon is dispersed in a resin.

[0101] The resin used for the transmittance adjusting layer 7 is not particularly limited as long as it can provide necessary reliability such as heat resistance. For example, an alkali-developable photosensitive resin or a thermosetting resin may be used. Examples of the thermosetting resin include a resin having at least one functional group selected from an epoxy group, a methylol group, an alkoxymethyl group, and an acyloxymethyl group. The transmittance adjusting layer 7 can be formed by adding a particulate additive containing at least carbon and an organic solvent to the above-mentioned resin to form a coating liquid in which the additive is dispersed, applying the coating liquid to the deposition surface, and curing the coating liquid.

[0102] The transmittance adjusting layer 7 may be a resin dispersion containing carbon as a main pigment. The transmittance of the transmittance adjusting layer 7 for visible light is not particularly limited as long as it is possible to provide the necessary display light brightness and suppress external light reflection as the first substrate 110. For example, it is more preferable that the transmittance of the transmittance adjusting layer 7 for visible light is in the range of 70% or more and 99.7% or less. The amount of carbon added to the resin in the transmittance adjusting layer 7 is appropriately set according to the required transmittance. For example, a transmittance in the range of 70% to 99.7% can be easily achieved by adding carbon, which is a black pigment, in the range of, for example, 0.2 wt% to 8 wt% relative to the resin solid content. If the amount of carbon added exceeds 9 wt%, or even 10 wt%, the transmittance of the transmittance adjusting layer will be too low. The transmittance adjusting layer 7 may contain transparent fine particles and organic pigments such as blue pigments in addition to carbon. As long as the necessary transmittance can be obtained, there is no particular limitation on the thickness of the transmittance adjusting layer 7. For example, the thickness of the transmittance adjusting layer 7 is preferably in the range of 0.1 μm to 1 μm, but may be more than 1 μm.

[0103] Micro LEDs and organic EL displays often have a light-reflective electrode underneath the LED or organic EL layer, which is the light-emitting element. In micro LEDs and organic EL displays with this structure, the re-reflected light of external incident light by the light-reflective electrode enters the observer's eyes, reducing visibility. In micro LEDs and organic EL displays, an expensive circular polarizer is usually used in combination with the display to eliminate the re-reflected light of external incident light. The visible light transmittance of a circular polarizer is about 50%.

[0104] The display device 100 of this embodiment is provided with a transmittance adjusting layer 7, which can suppress re-reflection of external incident light (external light) by light-reflective members inside the display device 100, such as light-reflective electrodes. When external light enters the display device 100 from the first substrate 110 side, the external light passes through the transmittance adjustment layer 7 once, is reflected by a light reflective member inside the display device 100, and then passes through the transmittance adjustment layer 7 again to be emitted to the viewer 59 side. In this way, the external light passes through the transmittance adjustment layer 7 twice to be emitted from the display device 100, and the amount of reflected external light that can be emitted to the outside is the amount of incident light multiplied by the square of the transmittance of the transmittance adjustment layer 7, so the amount of reflected external light that is emitted is significantly attenuated compared to when the transmittance adjustment layer 7 is not provided. For example, if the visible light transmittance of the transmittance adjustment layer 7 is 70%, this corresponds to the reflectance of the internal light reflective member being substantially 49%, and therefore has a higher effect of suppressing external light reflection than a display device having a circular polarizer with a transmittance of 50% instead of the transmittance adjustment layer 7. A circular polarizer also transmits only 50% of the display light from the light-emitting elements, whereas the display device 100 having the transmittance adjustment layer 7 instead of the circular polarizer 11 transmits 70% of the display light emitted from the light-emitting elements 24, enabling a brighter display. The display device 100 does not have a circular polarizer 11 and has a transmittance adjustment layer 7 with a visible light transmittance of approximately 70%, so that it can be manufactured inexpensively since it does not have an expensive circular polarizer 11, and enables bright display while suppressing external light reflection.

[0105] According to the transmittance adjusting layer 7, the transmittance of the display light is always greater than the substantial reflectance of the external light, so that the brightness of the reflected external light can be suppressed compared to the brightness of the display light. For example, even if the transmittance of the transmittance adjusting layer 7 is less than 70%, if it is 50% or more, the brightness of the display light is equal to or greater than that of a display device having a circular polarizer with a transmittance of 50%, and the amount of reflected external light is significantly suppressed, improving the display contrast and enabling an inexpensive configuration. When the display device 100 includes the circular polarizer 11, the circular polarizer 11 also suppresses external light reflection, so the transmittance of the transmittance adjustment layer 7 is more preferably higher than 70% within a range in which the necessary external light reflection suppression effect can be obtained. In this case, the contrast of the display light, which makes it easier to create a relative difference between the external light reflection and the brightness of the display light, is improved according to the transmittance of the transmittance adjustment layer 7.

[0106] Furthermore, many liquid crystal display devices use two polarizing plates in a crossed Nicol arrangement (with polarization axes perpendicular to each other). When using such a circular polarizing plate or polarizing plate, fine particles that do not cause polarization distortion, are optically isotropic, and are transparent in the visible range can be added to the transmittance adjusting layer 7 in order to improve dispersion or reduce the refractive index of the semi-transmitting film.

[0107] For example, when the transmittance adjusting layer 7 is a transparent inorganic film or a resin film with a visible light transmittance close to 100%, ripples due to interference in light reflection at the interface with the first black matrix layer 1 may occur. In this case, the first black matrix layer 1 may be observed to be slightly colored. Such slight coloring caused by reflected light is easily observed when the display device 100 is turned off and black display is displayed. In such a case, it may appear rainbow-colored when viewed from an oblique direction by an observer, which may reduce visibility.

[0108] In contrast, by using silica fine particles and carbon in combination to form the transmittance adjusting layer 7, it is possible to obtain the effect of reducing the size of such ripples. From the above viewpoint, the transmittance adjusting layer 7 containing fine particles that are transparent in the visible range is also useful. The same effect can be obtained by not containing silica fine particles but containing a low concentration of carbon.

[0109] The particle size of the transparent particles such as silica fine particles used in combination with carbon is not particularly limited, but for example, transparent particles having an average primary particle size of 3 nm to 100 nm can be used.

[0110] When the transmittance adjusting layer 7 is formed with an organic pigment as the main pigment component, external light reflected at the interface with the first black matrix layer 1 may appear colored yellow. In contrast, the transmittance adjusting layer 7 containing carbon as the main pigment component has a nearly flat reflected light and is hardly colored. Flat reflected light means that within the visible range of light wavelengths from 400 nm to 700 nm, for example, in a small range of 50 nm, there is no unevenness (fluctuation) of 2% or more in transmittance, and a transmittance curve that is close to a straight line is obtained. For example, when the visible range of 400 nm to 700 nm is divided into 50 nm units, the transmittance adjusting layer 7 containing carbon as a main pigment component can have a reflectance fluctuation (ripple) of 1.0% or less within the 50 nm unit. In the visible range of light wavelengths of 400 nm to 700 nm, the reflectance at the interface with the first black matrix layer 1 can be set within a range of 0.01% to 1.0%. The reflectance fluctuation (ripple) is the difference between the peaks and valleys of the reflectance spectral curve within the above-mentioned 50 nm unit of the reflectance measured within the visible range of light wavelengths of 400 nm to 700 nm, but the reflectance peak value within the 50 nm unit may be used as a simplified evaluation. In the latter simplified evaluation, the reflectance fluctuation value appears to be a large value. However, the reflectance here is the reflectance measured through the first substrate 110 and the transmittance adjusting layer 7, with the reflectance of an aluminum film taken as the reference (100%). The measurement can be easily performed using, for example, a microspectrophotometer. In addition, the transmittance spectrum of carbon has a slightly higher transmittance for red. In order to make the transmittance spectrum of the transmittance adjustment layer 7 flatter, the transmittance adjustment layer 7 may contain a blue pigment that has a high absorptance for red together with carbon.

[0111] In the display device 100 of this embodiment, a laminate including a first substrate 110, a color filter 2, a wavelength conversion layer 3, a first black matrix layer 1, and a light-reflective matrix layer 6 and forming an upper layer of the display device 100 constitutes a wavelength conversion substrate 130 of this embodiment used in the display device 100 of this embodiment. The wavelength conversion substrate 130 may further include at least one of a circular polarizer 11, a transmittance adjusting layer 7, and a transparent resin adhesive layer 9.

[0112] The method for manufacturing the display device 100 of this embodiment is not particularly limited as long as it is possible to form the above-mentioned layered structure. For example, the display device 100 can be manufactured by forming an upper laminate 100A on the negative side of the z-axis relative to the transparent resin adhesive layer 9, and a lower laminate 100B on the positive side of the z-axis relative to the transparent resin adhesive layer 9, and bonding the upper laminate 100A and the lower laminate 100B together with an adhesive that forms the transparent resin adhesive layer 9. The upper laminate 100A can be formed as follows. First, the color filter 2, the first black matrix layer 1, and the light-reflecting matrix layer 6 are formed in this order on the surface 110b side of the first substrate 110 on which at least one of the circular polarizer 11 and the transmittance adjustment layer 7 is laminated as necessary, and pixel openings Or, Og, and Ob penetrating the first black matrix layer 1 and the light-reflecting matrix layer 6 are formed. After this, the red conversion layer 3R, the green conversion layer 3G, and the light scattering layer 3B are laminated in each of the pixel openings Or, Og, and Ob. In this way, the upper laminate 100A is formed. The lower laminate 100B can be formed as follows. First, the third insulating layer 36, the second insulating layer 35, and the first insulating layer 34 are laminated in this order on the upper surface 120a of the second substrate 120, on which the heat dissipation film 10 is laminated as necessary on the lower surface 120b, to form a thin film transistor (not shown), and the light emitting element 24 is formed or arranged on the first insulating layer 34, and the partition wall 37 is formed. After that, the upper electrode 23 that covers the light emitting element 24 and the partition wall 37 is laminated, and the auxiliary conductor 31 is arranged as necessary. In this way, the lower laminate 100B is formed. Thereafter, an adhesive that will form a transparent resin adhesive layer 9 after curing is applied to the lower surface of the upper laminate 100A or the upper surface of the lower laminate 100B, the upper laminate 100A and the lower laminate 100B are bonded together, and the adhesive is cured. In this manner, the display device 100 can be manufactured.

[0113] In this manner, with a configuration in which the upper laminate 100A and the lower laminate 100B are laminated, for example, repair (replacement) of a defective chip of the light emitting element 24 mounted on the second substrate 120 is easy.

[0114] However, the manufacturing method of the display device 100 is not limited to this. For example, each layer of the display device 100 may be formed on the second substrate 120 in sequence, or may be formed on the first substrate 110 in sequence. The color filter 2 is preferably formed in a laminate including the first substrate 110, but may also be laminated in an on-array form on a laminate including the second substrate 120.

[0115] Next, the operation of the display device 100 will be described. The light emission of the plurality of light-emitting elements 24 is controlled in response to a video signal input from the outside. For example, the light-emitting element 24 facing the red conversion layer 3R is driven by a video signal corresponding to a red component. The light-emitting element 24 facing the green conversion layer 3G is driven by a video signal corresponding to a green component. The light-emitting element 24 facing the light scattering layer 3B is driven by a video signal corresponding to a blue component. When driven, each of the light emitting elements 24 emits blue light or near-ultraviolet monochromatic light. In the following, an example in which the light emitting element 24 emits blue light will be described.

[0116] For example, blue light emitted from the light-emitting element 24 facing the red conversion layer 3R passes through the upper electrode 23 and the transparent resin adhesive layer 9, and is diffused around the negative z-axis direction. Light incident on the pixel opening Or interacts with the red conversion particles 12 while being scattered by the light scattering particles 17, and is wavelength-converted into red secondary light by the red conversion particles 12. The secondary light passes through the red filter R toward the first substrate 110. The red filter R transmits the red wavelength light with almost no loss. On the other hand, the wavelength components that are not wavelength-converted by the red conversion particles 12 are blocked by the red filter R. When the display device 100 has a transmittance adjusting layer , the red light transmitted through the red filter R is attenuated according to the transmittance of the transmittance adjusting layer . When the display device 100 has a circular polarizer 11 , the polarized light component of the circular polarizer 11 that is perpendicular to the absorption axis of the linear polarizer passes through the circular polarizer 11 .

[0117] In this way, blue light driven by a video signal corresponding to a red component is wavelength-converted to red light in the red conversion layer 3R and passes through the first substrate 110 to be emitted to the outside. In contrast, blue light that cannot directly enter the pixel opening Or, for example, by being emitted from a side surface of the light-emitting element 24 or emitted in an oblique direction, or blue light that enters the pixel opening Or but is scattered downward, is reflected downward by the light-reflective matrix layer 6. This blue light is reflected upward by a light-reflective member inside the display device 100 below the light-reflective matrix layer 6, and at least a portion of the blue light enters the pixel opening Or. For this reason, in this embodiment, the optical loss of the blue light entering the pixel opening Or is reduced. 1, the light-reflective matrix layer 6 is laminated on the entire lower surface of the first black matrix layer 1 surrounding the pixel opening Or. Therefore, light is not absorbed by the first black matrix layer 1, and blue light can be reflected more efficiently.

[0118] The blue light emitted from the light-emitting element 24 facing the green conversion layer 3G enters the pixel opening Og or the light-reflective matrix layer 6 around the pixel opening Og, and is emitted as green light from the first substrate 110 in the same manner as the blue light emitted from the light-emitting element 24 facing the red conversion layer 3R, except that the blue light is wavelength-converted into green secondary light as it passes through the pixel opening Og. The blue light emitted from the light-emitting element 24 facing the light-scattering layer 3B enters the pixel opening Ob or the light-reflective matrix layer 6 around the pixel opening Ob, and is scattered by the light-scattering particles 17 without being wavelength-converted as it passes through the pixel opening Ob, and is emitted as blue light from the first substrate 110 in the same manner as the blue light emitted from the light-emitting element 24 facing the red conversion layer 3R.

[0119] In this embodiment, each light-emitting element 24 is surrounded by partition walls 37 that narrow in the negative direction of the z-axis, so that light components emitted from the sides are more likely to travel toward the pixel openings Or, Og, and Ob that the light-emitting element 24 faces. Furthermore, the pixel openings Or, Og, and Ob are separated from each other in a plan view by the first black matrix layer 1. This prevents color mixing caused by light emitted from adjacent light-emitting elements 24 driven by different video signals.

[0120] In the case of a display device 100 having at least one of a transmittance adjusting layer 7 and a circular polarizer 11, as described above, the reflected light of external light entering the inside of the display device 100 from the outside is attenuated, thereby suppressing a decrease in the contrast of the display light due to the influence of external light reflection.

[0121] As described above, the display device 100 of this embodiment includes a transparent first substrate 110, a color filter 2 facing the first substrate 110 in the thickness direction of the first substrate 110, a first black matrix layer 1 disposed facing the first substrate 110 and having a plurality of pixel openings Or, Og, and Ob formed therein, the first black matrix layer 1 being formed with a plurality of pixel openings Or, Og, and Ob opening toward the color filter 2, a light-reflecting matrix layer 6 laminated on a lower surface 1b, which is the surface of the first black matrix layer 1 opposite to the first substrate, in an area excluding the plurality of pixel openings Or, Og, and Ob, and ... of the first black matrix layer 1 opposite to the first substrate, the light-reflecting matrix layer 6 being laminated on a range excluding the plurality of pixel openings Or, Og, and Ob in a plan view. The pixel electrode 110 includes a wavelength conversion layer 3 that is disposed between the color filter 2 and the light-reflective matrix layer 6 so as to overlap with at least one of the openings Or, Og, Ob, and that converts the wavelength of light that passes through at least one of the pixel openings Or, Og, Ob toward the color filter 2; a plurality of light-emitting elements 24 that radiate light toward each of the pixel openings Or, Og, Ob from the side opposite the first substrate 110 across the first black matrix layer 1; and a second substrate 120 on which the plurality of light-emitting elements 24 are disposed, facing the first substrate 110. That is, the display device 100 of this embodiment includes a wavelength conversion substrate 130, a plurality of light emitting elements 24, and a second substrate 120. With this configuration, the display device 100 of this embodiment and the wavelength conversion substrate 130 used therein both have the light-reflecting matrix layer 6, and therefore the brightness of the display can be improved compared to a case in which the light-reflecting matrix layer 6 is not included. In particular, in this embodiment, the blue light can be wavelength-converted to red and blue independently by the red conversion layer 3R and the green conversion layer 3G, so that the luminance of the light emitting element 24 can be reduced compared to the case where white light is produced from blue light. As a result, heat generation from the light emitting element 24 can be suppressed.

[0122] [Second embodiment] A display device and a wavelength conversion substrate according to a second embodiment will be described. Fig. 2 is a partial cross-sectional view of the display device according to the first embodiment of the present invention, Fig. 3 is an enlarged view of a portion F3 in Fig. 2.

[0123] A display device 200 shown in Fig. 2 is an example of a display device according to this embodiment. The x-axis, y-axis, and z-axis shown in Fig. 2 are defined in the same way as in Fig. 1. The x-axis, y-axis, and z-axis in the other drawings below are also defined in the same way. The display device 200 has the same configuration as the display device 100, except that a second black matrix layer 8 is further disposed between the color filter 2 and the first substrate 110 in the display device 100 according to the first embodiment. Therefore, the display device 200 has a wavelength conversion substrate 230 of this embodiment in which a second black matrix layer 8 is added to the wavelength conversion substrate 130 of the first embodiment. The following description will focus on the differences from the first embodiment.

[0124] [Second black matrix layer] The position of the second black matrix layer 8 in the z-axis direction is not particularly limited as long as it is closer to the first substrate 110 than the upper surface 1a of the first black matrix layer 1. However, it is more preferable that the position of the second black matrix layer 8 is closer to the first substrate 110. In the example shown in FIG. 2, the second black matrix layer 8 is disposed at a position separated from the upper surface 1a with the color filter 2 interposed therebetween, and the upper surface of the second black matrix layer 8 is in contact with the lower surface of the transmittance adjusting layer . By positioning the second black matrix layer 8 below the transmittance adjusting layer 7, reflection of external light on the surface of the second black matrix layer 8 can be reduced. When the transmittance adjusting layer 7 is not provided, the second black matrix layer 8 may be in contact with the surface 110b of the first substrate 110.

[0125] The second black matrix layer 8 has a planar shape similar to that of the first black matrix layer 1. The second black matrix layer 8 may have a planar shape that overlaps with the first black matrix layer 1, or may have a shape that overlaps the inside of the first black matrix layer 1. When the second black matrix layer 8 has a shape that overlaps with the inside of the first black matrix layer 1, it is more preferable that the line width of the second black matrix layer 8 is close to the line width of the first black matrix layer 1. However, when at least one of the line width and the arrangement position varies due to manufacturing errors, or when there is a margin in the light output of the light-emitting element 24, a part of the first black matrix layer 1 may protrude to some extent from the second black matrix layer 8 in a planar view.

[0126] In the example shown in FIG. 2, the shape of the second black matrix layer 8 in a plan view is the same as the shape of the first black matrix layer 1, and they overlap each other in a plan view. That is, the second black matrix layer 8 has a rectangular lattice pattern in plan view, and the line width center in each of the first direction (X direction) and the second direction (Y direction) is the same as the line width center of the first black matrix layer 1. The second black matrix layer 8 has openings or, og, and ob having the same shapes as the pixel openings Or, Og, and Ob of the first black matrix layer 1 penetrating therethrough in the thickness direction. The centers of the openings or, og, and ob coincide with the centers of the corresponding pixel openings Or, Og, and Ob in plan view.

[0127] The second black matrix layer 8 is formed in the same manner as the first black matrix layer 1, except for the layer thickness and the position in the z-axis direction. In particular, in the example shown in FIG. 2, the line width of the second black matrix layer 8 is also the same as that of the first black matrix layer 1.

[0128] According to the display device 200 of the present embodiment, the second black matrix layer 8 is disposed above the upper surface 1a of the first black matrix layer 1. Therefore, of the light emitted from the pixel openings Or, Og, Ob, the light that travels obliquely toward the outside of the pixel openings Or, Og, Ob as it travels in the negative direction of the z-axis is blocked by the back surface of the second black matrix layer 8 outside the openings or, og, ob of the second black matrix layer 8. As a result, of the light traveling from the openings or, og, and ob toward the first substrate 110, stray light traveling in an oblique direction toward adjacent pixels is blocked, thereby reducing color mixture between adjacent pixels and improving display quality. The display quality can be improved more as the sizes of the openings or, og, and ob approach the sizes of the pixel openings Or, Og, and Ob.

[0129] For example, even if the line width of the second black matrix layer 8 is the same as that of the first black matrix layer 1, if the second black matrix layer 8 is not in a matrix shape but in a stripe shape extending in the x-axis or y-axis direction, the emitted light spreading in the extension direction from adjacent pixels in the extension direction of the second black matrix layer 8 cannot be regulated, and color mixing in the extension direction is likely to occur. The second black matrix layer 8 has a matrix shape similar to that of the first black matrix layer 1, and therefore can suppress color mixing with adjacent pixels in both the x-axis and y-axis directions.

[0130] Here, the configuration briefly described in the first embodiment will be described in more detail. In the following description, unless otherwise specified, the same reference numerals as in the first embodiment may also be used for the same configuration. FIG. 3 is an enlarged view of part B in FIG. 3 is an example of a light-reflective matrix layer 6 made of a metal thin film 22 of aluminum or an aluminum alloy. More preferable conditions for the aluminum or aluminum alloy used for the metal thin film 22 are as described for the light-reflective matrix layer 6 of the first embodiment.

[0131] The light-reflective matrix layer 6 shown in FIG. 3 may be replaced with Modification 1 shown in FIG. FIG. 4 shows a first modification of the light-reflective matrix layer shown in FIG. Variation 1 of the light-reflective matrix layer 6 shown in FIG. 4 has a three-layer structure in which a first conductive oxide thin film 18, a metal thin film 19, and a second conductive oxide thin film 20 are laminated in this order on the lower surface 1b of the first black matrix layer 1.

[0132] Silver or a silver alloy is used as the material of the metal thin film 19. As described in relation to the light-reflective matrix layer 6 of the first embodiment, a different metal may be added to the silver or silver alloy for the purpose of suppressing the diffusion of silver. Therefore, the metal thin film 19 only needs to contain silver or a silver alloy. The thickness of the metal thin film 19 can be, for example, 100 nm or more and 300 nm or less. However, the thickness of the metal thin film 19 may be thicker than 300 nm. In this case, heat generated in the light emitting element 24 is easily diffused by thermal conduction through the metal thin film 19, so that the temperature rise in the vicinity of the light emitting element 24 due to heat generation from the light emitting element 24 can be reduced.

[0133] The first conductive oxide thin film 18 and the second conductive oxide thin film 20 are thin films containing indium oxide and having electrical conductivity. The first conductive oxide thin film 18 and the second conductive oxide thin film 20 may contain, in addition to indium oxide, metal oxides such as zinc oxide, tin oxide, and titanium oxide. The film thickness of the first conductive oxide thin film 18 and the second conductive oxide thin film 20 may be, for example, 10 nm or more and 50 nm or less, however, the film thickness of the first conductive oxide thin film 18 and the film thickness of the second conductive oxide thin film 20 may be the same as or different from each other. Since the first conductive oxide thin film 18 and the second conductive oxide thin film 20 sandwich the metal thin film 19 containing silver or a silver alloy, diffusion of silver atoms in the metal thin film 19 can be prevented. Since the second conductive oxide thin film 20 has good transmittance, the light-reflective matrix layer 6 in the first modification has light reflectivity resulting from the light reflectivity of the metal thin film 19 .

[0134] The light-reflective matrix layer 6 shown in FIG. 3 may be replaced by Modification 2 shown in FIG. FIG. 5 shows a second modification of the light-reflective matrix layer shown in FIG. Modification 2 of the light-reflective matrix 6 shown in FIG. 3 has a configuration in which a thin film 21 and a metal thin film 22 are laminated in this order on the lower surface 1b of the first black matrix layer 1. That is, the modified example 2 of the light-reflective matrix layer 6 differs from the light-reflective matrix layer 6 shown in FIG. 6 in that the thin film 21 is disposed between the metal thin film 22 and the lower surface 1b.

[0135] The thin film 21 is provided for the purpose of improving the adhesion between the thin metal film 22 and the first black matrix layer 1. Since the thin metal film 22 contains aluminum or an aluminum alloy, titanium or titanium nitride is suitable as the material of the thin film 21. Since the lower surface of the thin film 21 is covered with the thin metal film 22, the thin film 21 does not need to have optical transparency. The thickness of the thin film 21 is not particularly limited as long as the thin film 21 can be adhered to the thin metal film 22 .

[0136] Since the thin film 21 has good adhesion to the first black matrix layer 1 and to the metal thin film 22, the metal thin film 22 adheres firmly to the first black matrix layer 1. This makes it possible to prevent the metal thin film 22 from peeling off during cleaning or transportation of the substrate in the manufacturing process, for example. For example, when a metal thin film made of a metal other than aluminum or an aluminum alloy is used instead of the metal thin film 22, the material of the thin film 21 may be changed according to the material of the metal thin film. For example, molybdenum, molybdenum nitride, etc. may be used as the metal thin film.

[0137] Next, an example of the detailed configuration of the periphery of the light emitting element 24 and the thin film transistor will be described. FIG. 6 is an enlarged view of a portion F6 in FIG. As shown in FIG. 6, the light emitting element 24 is electrically connected to a thin film transistor 49 that drives the light emitting element 24 via a lower electrode 28, a reflective electrode 29, and a connection layer 30 embedded in a contact hole 32. The thin film transistor 49 is formed inside the third insulating layer 36 and the second insulating layer 35. The number and thicknesses of the insulating layers such as the first insulating layer 34, the second insulating layer 35, and the third insulating layer 36 are not limited to those shown in the figure. The thin film transistor 49 is composed of a semiconductor layer 38, a gate electrode 39, a gate insulating film 33, a drain electrode 40, a source electrode 41, a light-shielding film 42, and the like. The drain electrode 40 is electrically connected to the connection layer 30 . Conductive parts such as the gate electrode 39, the drain electrode 40, the source electrode 41, and the connection layer 30 may be formed of three-layer conductive wiring of silver or a silver alloy sandwiched between conductive oxides. The configuration and material of these conductive wiring may be the same as those of the first modification of the light-reflective matrix layer 6 shown in FIG.

[0138] FIG. 7 is an example of a circuit diagram for driving a light-emitting element using a thin film transistor or the like. Each pixel PX includes one or more (one in the figure) light-emitting elements 24 and two or more (two in the figure) thin-film transistors 49, and a plurality of pixels PX are arranged in a matrix. Each thin-film transistor 49 in the pixel PX receives a gate signal from the scanning signal circuit 43 via a gate line 48, which is a conductive wiring, and a video signal from the video signal circuit via a source line 46, which is a conductive wiring, to drive the light-emitting element 24. Power to the light-emitting element 24 is supplied from a power line 47, which is a conductive wiring. The light-emitting element 24 emits light in accordance with the amount of current from the power line 47. 7, reference numeral 50 denotes a first thin film transistor, reference numeral 51 denotes a second thin film transistor, and reference numeral 52 denotes a capacitance element. The first thin film transistor 50 receives a video signal from the source line 46 and a scanning signal from the gate line 48, and sends a selection signal to the second thin film transistor 51 to drive the second thin film transistor 51. The second thin film transistor 51 receives the selection signal and passes a current from the power line 47 to the light emitting element 24 (LED), causing the LED to emit light. The capacitance element 52 stabilizes the voltage applied to the light emitting element 24.

[0139] FIG. 8 is a partial plan view showing the shapes of the auxiliary conductors and the light-reflective matrix layer in plan view. 8, the auxiliary conductor 31 has a matrix shape in plan view similar to that of the first black matrix layer 1 and the light-reflective matrix layer 6. However, the line width Cx of the auxiliary conductor 31 in the x-axis direction is narrower than the line width Bx of the first black matrix layer 1 in the x-axis direction. The line width Cy of the auxiliary conductor 31 in the y-axis direction is narrower than the line width Bx of the first black matrix layer 1 in the y-axis direction. Since the centers of the pixel openings Or, Og, and Ob coincide with the centers of the openings or, og, and ob, the inner edges of the openings or, og, and ob are located outside the pixel openings Or, Og, and Ob, and are covered by the first black matrix layer 1 in plan view. Therefore, as shown in FIG. 2, even if an observer 59 looks from outside the display device 200 in the direction of arrow P, the auxiliary conductors 31 are hidden by the second black matrix layer 8 and the first black matrix layer 1 and cannot be seen. Since the auxiliary conductor 31 contains metal, it has light reflectivity; however, since it is invisible from the outside when viewed in a plan view, there is little possibility that external light directly enters the auxiliary conductor 31, is reflected by it, and is emitted to the outside through each pixel opening Or, Og, Ob. On the other hand, the auxiliary conductors 31 reflect upward the light that has been reflected downward by the light-reflective matrix layer 6, thereby improving the efficiency of using the light emitted from the light-emitting elements 24. The wider the line widths Cx and Cy of the auxiliary conductor 31 are within a range that cannot be seen from the outside, the more improved the heat dissipation effect described in the first embodiment.

[0140] The display device 200 of this embodiment can be manufactured in the same manner as the display device 100 of the first embodiment, except that the second black matrix layer 8 is disposed between the first substrate 110 and the color filter 2.

[0141] The display device 200 of this embodiment includes the same configuration as the display device 100, and therefore can improve the brightness of the display, similarly to the display device 100 of the first embodiment. In particular, in this embodiment, the display device 200 further includes a second black matrix layer 8 between the first black matrix layer 1 and the first substrate 110, and the second black matrix layer 8 includes a plurality of openings or, og, ob that overlap with a plurality of pixel openings Or, Og, Ob, respectively, in a planar view, thereby suppressing color mixing of the display light and further improving the display quality.

[0142] [Third embodiment] A display device and a wavelength conversion substrate according to a third embodiment will be described. FIG. 9 is a partial cross-sectional view of a display device according to a third embodiment of the present invention.

[0143] A display device 300 shown in FIG. 9 is an example of the display device according to this embodiment. The display device 300 has a similar configuration to the display device 200, except that it has a wavelength conversion layer 4 instead of the wavelength conversion layer 3 and light scattering layer 3B in the display device 200 of the second embodiment, and that a transmittance adjustment layer 7 is disposed between the color filter 2 and the wavelength conversion layer 4. However, the transmittance adjusting layer 7 in this embodiment may be disposed between the first substrate 110 and the second black matrix layer 8 and the color filter 2, similar to the display device 200. Furthermore, the transmittance adjusting layer 7 in this embodiment may be omitted, similar to the second embodiment. In the display device 300 of this embodiment, a laminate including the first substrate 110, the second black matrix layer 8, the color filter 2, the wavelength conversion layer 4, the first black matrix layer 1, and the light-reflective matrix layer 6 and forming the upper layer of the display device 300 constitutes a wavelength conversion substrate 330 of this embodiment used in the display device 100 of this embodiment. The following description will focus on the differences from the second embodiment.

[0144] The wavelength conversion layer 4 is a layer portion disposed between the first black matrix layer 1 and the transmittance adjusting layer 7, and covers the entire pixel openings Or, Og, and Ob from the negative z-axis direction side. The wavelength conversion layer 4 is formed by laminating a red conversion layer 3R and a green conversion layer 3G in this order in the negative z-axis direction. The red conversion layer 3R and the green conversion layer 3G in this embodiment are similar to the red conversion layer 3R and the green conversion layer 3G in the second embodiment, except that they are layers covering the negative z-axis side of the first black matrix layer 1 in which multiple pixel openings Or, Og, and Ob are formed.

[0145] In the second embodiment, the first black matrix layer 1 has a red conversion layer 3R and a green conversion layer 3G formed inside multiple pixel openings Or, Og, and Ob, so the thickness of the first black matrix layer 1 needs to be a thickness required for wavelength conversion in the red conversion layer 3R and the green conversion layer 3G. However, in this embodiment, the red conversion layer 3R and the green conversion layer 3G are not formed inside the pixel openings Or, Og, and Ob of the first black matrix layer 1, so the thickness of the first black matrix layer 1 can be set independently of the thicknesses of the red conversion layer 3R and the green conversion layer 3G based on the required light blocking property. In particular, the light blocking property of the first black matrix layer 1 is improved by the light reflective matrix layer 6, so the thickness of the first black matrix layer 1 can be made thinner than the thicknesses of the red conversion layer 3R and the green conversion layer 3G. The thickness of the red conversion layer 3R and the thickness of the green conversion layer 3G can be set based on the required wavelength conversion performance and the content of the red conversion particles 12 and the green conversion particles 13. Therefore, the thickness of the red conversion layer 3R and the thickness of the green conversion layer 3G may be the same as or different from each other. Here, the required wavelength conversion performance may include, for example, converting approximately ⅓ of the blue light transmitted in the thickness direction into red and green light, respectively.

[0146] In this embodiment, a two-layer wavelength conversion layer 4 is sandwiched between the first black matrix layer 1 and the second black matrix layer 8. Therefore, the distance between the first black matrix layer 1 and the second black matrix layer 8 is greater than in the second embodiment, and the display light is likely to be scattered inside the wavelength conversion layer 4 and spread outside the range of the pixel openings Or, Og, Ob in a planar view. As a result, the size and shape of the openings or, og, ob are likely to determine the actual size and shape of the pixel, and it is particularly preferable to match the shape and size of the openings or, og, ob to the pixel openings Or, Og, Ob.

[0147] The display device 300 of this embodiment can be manufactured in the same manner as the display device 200 of the second embodiment, except that the wavelength conversion layer 4 is disposed between the first substrate 110 and the color filter 2.

[0148] In the display device 300, the blue light emitted from each light-emitting element 24 passes through the pixel openings Or, Og, and Ob, respectively, and then passes through the red conversion layer 3R, which is a long-wavelength conversion layer, and the green conversion layer 3G, which is a shorter-wavelength conversion layer, in that order. In the red conversion layer 3R, for example, about ⅓ of the blue light is wavelength-converted into red light. In the green conversion layer 3G, for example, about 1 / 3 of the incident blue light is wavelength-converted to green light. At this time, the red light does not contain a short-wavelength component that can be wavelength-converted in the green conversion layer 3G, so it passes through the green conversion layer 3G as red light. As a result, red light and green light formed by wavelength conversion and blue light that has not been wavelength converted reach color filter 2. As a result, red light is emitted from red filter R, green light is emitted from green filter G, and blue light is emitted from blue filter B. Therefore, the display device 300 can perform color display similar to that of the display device 200.

[0149] The display device 300 of this embodiment includes a configuration similar to that of the display device 200, and therefore can improve the brightness of the display, similar to that of the display device 200 of the second embodiment. In particular, in this embodiment, the red conversion layer 3R and the green conversion layer 3G do not need to be patterned, making the manufacture easier than the display device 200 in which the red conversion layer 3R and the green conversion layer 3G need to be patterned. In addition, the thickness of the first black matrix layer 1 can be reduced, which makes the manufacturing process easier.

[0150] In this embodiment, the amount of light emitted by the light-emitting element 24 needs to be increased compared to the display device 200, but heat dissipation can be promoted by providing, for example, a heat dissipation film 10, an auxiliary conductor 31, a thin metal film in the light-reflective matrix layer 6, etc.

[0151] [Fourth embodiment] A display device and a wavelength conversion substrate according to a fourth embodiment will be described. FIG. 10 is a partial cross-sectional view of a display device according to a fourth embodiment of the present invention.

[0152] A display device 400 shown in FIG. 10 is an example of the display device according to this embodiment. The display device 400 has a similar configuration to the display device 300, except that it has a wavelength conversion layer 4 instead of the wavelength conversion layer 4 in the display device 300 of the third embodiment, and that a second black matrix layer 8 is disposed between the transmittance adjusting layer 7 and the color filter 2. 10 is merely an example, and their positions in the z-axis direction may be appropriately interchanged. For example, the positional relationship may be the same as that of the display devices 200 and 300. In the display device 400 of this embodiment, a laminate including the first substrate 110, the second black matrix layer 8, the color filter 2, the wavelength conversion layer 5, the first black matrix layer 1, and the light-reflective matrix layer 6 and forming the upper layer of the display device 400 constitutes a wavelength conversion substrate 430 of this embodiment used in the display device 100 of this embodiment. The following description will focus on the differences from the third embodiment.

[0153] The wavelength conversion layer 5 is composed of one layer in which red conversion particles 12 and green conversion particles 13 are dispersed in a resin 15 . The content of the red conversion particles 12 and the green conversion particles 13 may be set so that approximately 1 / 3 of the blue light passing through the wavelength conversion layer 5 in the thickness direction is converted to red and green, respectively, and the remaining blue light passes through without being wavelength converted.

[0154] The display device 400 can be manufactured in the same manner as the display device 300, except that a wavelength conversion layer 5 is formed instead of the wavelength conversion layer 4, and the color filter 2, the transmittance adjusting layer 7, and the second black matrix layer 8 are formed in a different order. The display device 400 according to this embodiment has a single wavelength conversion layer 5, which reduces the number of coating steps for forming the wavelength conversion layer 5, and therefore can be manufactured more quickly and easily.

[0155] In the display device 400, the blue light emitted from each light-emitting element 24 passes through the pixel openings Or, Og, and Ob, respectively, and then passes through the wavelength conversion layer 5 in which red conversion particles 12 and green conversion particles 13 are mixed. Therefore, about 2 / 3 of the blue light is wavelength-converted into red light and green light while passing through the wavelength conversion layer 5. The remaining approximately 1 / 3 of the blue light is not wavelength-converted. Therefore, red light, green light, and blue light that have passed through the wavelength conversion layer 5 are emitted from the red filter R, green filter G, and blue filter B, respectively. Therefore, the display device 400 can perform color display similar to that of the display device 300.

[0156] In the present embodiment, the wavelength conversion layer 5 has a single-layer structure, and therefore the thickness of the wavelength conversion layer 5 is thinner than that of the wavelength conversion layer 4 of the display device 300. This reduces the degree of scattering of light transmitted through the wavelength conversion layer 5, thereby suppressing the occurrence of stray light.

[0157] According to the display device 300 of this embodiment, since it includes a configuration similar to that of the display device 300, it is possible to improve the brightness of the display, similarly to the display device 300 of the third embodiment. In particular, in this embodiment, the generation of stray light is suppressed, so that the loss of light blocked by the second black matrix layer 8 can be reduced, enabling a brighter display.

[0158] In the above-described first and second embodiments, an example has been described in which the color filter 2 is disposed between the upper surface 1a of the first black matrix layer 1 and the first substrate 110. However, the color filter 2 may have red filters R, green filters G, and blue filters B disposed inside the multiple openings Or, Og, and Og, respectively, as long as they are closer to the first substrate 110 than the wavelength conversion layer 3 and the light scattering layer 3B.

[0159] In the above-described embodiments, the light-emitting element 24 is mainly described as a blue LED. However, in each embodiment, the light-emitting element 24 may be a near-ultraviolet LED. In this case, the red conversion particles 12 and the green conversion particles 13 in each wavelength conversion layer are conversion particles that convert the wavelength of near-ultraviolet light to red and green, respectively. Furthermore, in the first and second embodiments, a blue color conversion layer containing blue color conversion particles is used in place of the light scattering layer 3B. In the third embodiment, a blue conversion layer containing blue conversion particles is laminated between a green conversion layer 3G and a transmittance adjusting layer . In the fourth embodiment, blue conversion particles are further laminated onto the resin 15 . However, when a near-ultraviolet LED is used, it is more preferable to use the above-described configuration which is a modification of the first or second embodiment.

[0160] In each of the above-described embodiments, the wavelength conversion layer includes the light scattering particles 17. However, if the radiation angle of the display light is distributed within a range of viewing angles required for the display device when the display light is emitted to the outside of the display device, the light scattering particles 17 in the wavelength conversion layer may be omitted.

[0161] In the above-mentioned first and second embodiments, the light-reflective matrix layer 6 has been described as having a single-layer, two-layer, or three-layer structure including at least a metal thin film. However, the layer structure of the light-reflective matrix layer 6 is not limited to this. Thin films such as other metal thin films and conductive oxide thin films may be further added to the layer structures exemplified. The same applies to the conductive wiring, which can have a layer structure similar to that of the light-reflective matrix layer 6.

[0162] In the above-described embodiments, the display device performs full-color display using a combination of red, green, and blue display lights. However, the types and number of colors of the display light are not limited to this depending on the application of the display device. For example, the wavelength conversion characteristics of the conversion element and the wavelength characteristics of the color filter can be appropriately changed according to the type of color of the display light.

[0163] The display device having the wavelength conversion substrate according to each of the above-mentioned embodiments can be used in various applications. Examples of electronic devices to which the display device according to each of the above-mentioned embodiments can be used include electronic devices such as mobile phones, portable game devices, portable information terminals, personal computers, electronic books, video cameras, digital still cameras, head-mounted displays, navigation systems, audio playback devices (car audio, digital audio players, etc.), copiers, facsimiles, printers, printer-combination devices, vending machines, automated teller machines (ATMs), personal authentication devices, optical communication devices, and IC cards. The above-described embodiments may be freely combined and used. It is preferable that an antenna is further mounted on an electronic device equipped with a display device according to an embodiment of the present invention to perform communication and contactless power supply and reception.

[0164] Although preferred embodiments of the present invention have been described and illustrated above, it should be understood that these are illustrative of the present invention and should not be considered as limiting. Additions, omissions, substitutions, and other modifications can be made without departing from the scope of the present invention. Thus, the present invention should not be considered as limited by the foregoing description, but is defined by the claims. [Explanation of symbols]

[0165] 1 First black matrix layer 2. Color Filter 3, 4, 5 Wavelength conversion layer 3B Light scattering layer 3G green conversion layer 3R Red conversion layer 6. Light-reflecting matrix layer 7 Transmittance adjustment layer 8 Second black matrix layer 10 Heat dissipation film 11 Circular polarizing plate 12 Red transformation particles 13 Green conversion particles 17 Light scattering particles 18 First conductive oxide thin film 19, 22 Metal thin film 20 Second conductive oxide thin film 21 Thin Film 23 Upper electrode 24 Light emitting element (LED) 28 Lower electrode 29 Reflecting electrode 31 Auxiliary conductor 37 Bulkhead 49 Thin-film transistor 50 First thin film transistor 51 Second thin film transistor 52 Capacitive element 59 Observer 100, 200, 300, 400 display devices 100A Top Stack 100B Lower laminate 110 First board 120 Second board 130 Wavelength conversion board B Blue filter G Green filter or, og, ob opening Or, Og, Ob pixel aperture R Red filter

Claims

1. A transparent first substrate; a color filter facing the first substrate in a thickness direction of the first substrate; a first black matrix layer disposed opposite the first substrate and having a plurality of pixel openings formed therein, the pixel openings opening toward the color filter; a light-reflective matrix layer laminated on a surface of the first black matrix layer opposite to the first substrate, except for the pixel openings; a wavelength conversion layer that is disposed between the color filter and the light-reflective matrix layer so as to overlap with at least one of the plurality of pixel openings in a plan view seen from a direction from the first substrate toward the first black matrix layer along a normal line to one surface of the first substrate in the thickness direction, and that converts a wavelength of light that passes through the at least one of the plurality of pixel openings toward the color filter; a plurality of LEDs that radiate light toward each of the plurality of pixel openings from a side opposite to the first substrate across the first black matrix layer; a second substrate on which the LEDs are arranged and which faces the first substrate; Equipped with a surface of the first black matrix layer facing the color filter and an entire surface of the wavelength conversion layer facing the color filter are flush with each other; Display device.

2. The light-reflective matrix layer includes a metal thin film of aluminum or an aluminum alloy. The display device according to claim 1 .

3. The light-reflective matrix layer includes a metal thin film of silver or a silver alloy. The display device according to claim 1 .

4. the light-reflective matrix layer includes a thin film of titanium or titanium nitride laminated on the first black matrix layer, and a thin metal film of aluminum or an aluminum alloy laminated on the thin film; The display device according to claim 1 .

5. the light-reflective matrix layer includes a first conductive oxide thin film containing indium oxide, a metal thin film of silver or a silver alloy laminated on the first conductive oxide thin film, and a second conductive oxide thin film containing indium oxide laminated on the metal thin film; The display device according to claim 1 .

6. Each of the plurality of LEDs is a blue light emitting LED, the wavelength conversion layer includes red conversion particles that convert blue light into red light and green conversion particles that convert blue light into green light; The display device according to claim 1 .

7. Each of the plurality of LEDs is a blue light emitting LED, the wavelength conversion layer includes, in order from the plurality of LEDs toward the color filter, a red conversion layer in which light scattering particles and red conversion particles are dispersed in a transparent resin, and a green conversion layer in which light scattering particles and green conversion particles are dispersed in a transparent resin; The display device according to claim 1 .

8. Each of the plurality of LEDs is a blue light emitting LED, the wavelength conversion layer is divided into a red conversion layer in which light scattering particles and red conversion particles are dispersed in a transparent resin, and a green conversion layer in which light scattering particles and green conversion particles are dispersed in a transparent resin; Any one of the red conversion layer, the green conversion layer, and a light scattering layer having light scattering particles dispersed in a transparent resin is disposed inside the plurality of pixel openings. The display device according to claim 1 .

9. Each of the plurality of LEDs is an LED that emits violet to near ultraviolet light, the wavelength conversion layer includes red conversion particles that convert violet to near-ultraviolet light into red light, green conversion particles that convert violet to near-ultraviolet light into green light, and blue conversion particles that convert violet to near-ultraviolet light into blue light; The display device according to claim 1 .

10. a second black matrix layer between the first black matrix layer and the first substrate; the second black matrix layer includes a plurality of openings each overlapping with the pixel openings in the plan view; The display device according to claim 1 .

11. a transmittance adjusting layer disposed between the first substrate and the wavelength conversion layer and configured to regulate transmission of external light; The display device according to claim 1 .

12. The transmittance adjusting layer contains carbon. The display device according to claim 11.

13. the second substrate includes thin film transistors that drive the plurality of LEDs, The thin film transistor includes a conductive portion made of any one of silver, a silver alloy, copper, and a copper alloy, and a conductive wiring in which the conductive portion is sandwiched between a conductive oxide. The display device according to claim 1 .

14. A heat dissipation film is formed on a surface of the second substrate opposite to a surface facing the first substrate. The display device according to claim 1 .

15. A transparent first substrate; a color filter facing the first substrate in a thickness direction of the first substrate; a first black matrix layer disposed opposite the first substrate and having a plurality of pixel openings formed therein, the pixel openings opening toward the color filter; a light-reflective matrix layer laminated on a surface of the first black matrix layer opposite to the first substrate, except for the pixel openings; a wavelength conversion layer that is disposed between the color filter and the light-reflective matrix layer so as to overlap with at least one of the plurality of pixel openings in a plan view seen from a direction from the first substrate toward the first black matrix layer along a normal line to one surface of the first substrate in the thickness direction, and that converts a wavelength of light that passes through the at least one of the plurality of pixel openings toward the color filter; Equipped with a surface of the first black matrix layer facing the color filter and an entire surface of the wavelength conversion layer facing the color filter are flush with each other; Wavelength conversion substrate.

Images