Black matrix substrate, and display device including the black matrix substrate

Abstract

To provide a black matrix substrate capable of improving a display contrast and a display brightness in such a display device as a liquid crystal display device, an LED display and an organic EL display device, and also to provide a display device having the black matrix substrate.SOLUTION: A black matrix substrate at least includes, on a transparent substrate: a transmittance adjustment layer; a first black matrix having a plurality of openings divided by a line width Ax in a first direction and a line width Ay in a second direction; a light scattering layer covering the openings and the first black matrix; a second black matrix having openings divided by a line width Bx in the first direction and a line width By in the second direction on the light scattering layer; and a light-reflective matrix having openings divided by a line width Cx in the first direction and a line width Cy in the second direction on the second black matrix. The line widths are in a relation shown in expressions (1) and (2) below: Ax>Bx≥Cx...(1), and Ay>By≥Cy...(2).SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a black matrix substrate used in a liquid crystal display device, a micro LED (LED display), an organic EL display device, etc., and further to a display device including the black matrix substrate.

Background Art

[0002] An information display device such as a liquid crystal display device, a micro LED (Light Emitting Diode) display, or an organic EL display device can be regarded as being composed of a black matrix substrate and a display function layer as shown in FIG. 1(a). The display function layer controls the amount of transmitted light for each pixel like liquid crystal by an electrical signal, or emits light with an intensity corresponding to the electrical signal like organic EL or micro LED, thereby displaying image information as a distribution of color and light intensity. The black matrix substrate has a function of suppressing the entry of light leakage from adjacent pixels through the gaps between pixels, the transmitted light in regions where the gaps are not controlled, and the reduction of contrast due to the reflection of external light. The present invention relates to the layer structure of the black matrix substrate shown in FIG. 1(b) described later and a display device using the same.

[0003] As described later, FIG. 5 shows a cross-section of a display device in the case where the display function layer is a micro LED. FIG. 6 shows a cross-section of a liquid crystal display device using a combination of a backlight using a mini LED light source as the display function layer and a liquid crystal that modulates the amount of light.

[0004] In recent years, a technique of using a direct-type backlight called a mini LED having a configuration in which a plurality of LED chips having a size of approximately 5 μm to 100 μm are arranged in a matrix in a liquid crystal display device has attracted attention. In a mini LED, usually, three types of LED chips (hereinafter, may be referred to as light-emitting elements) of red light emission, green light emission, and blue light emission are used.

[0005] In addition, a technique that combines local dimming to partially adjust the emission luminance of three types of LED chips or partially stop the emission according to the position of the display area on the display screen has attracted attention. In a liquid crystal display device using such local dimming, since the emission on the display screen can be partially turned off, the contrast of the display can be greatly improved. In a conventional liquid crystal display device, since the backlight is always lit, a slight light leakage occurs when the liquid crystal is in a black display state, and it has been difficult to obtain a contrast comparable to that of an organic EL.

[0006] Micro-LED is a display device having a structure in which LED chips with a size of approximately 2 μm to 100 μm are arranged in a matrix, and the display is performed by individually driving each of the plurality of LED chips. Such micro-LED can perform display without using liquid crystal.

[0007] Micro-LED is roughly classified into a method using three types of LED chips that emit red light, green light, and blue light, similar to the above-described mini-LED, and a method using only monochromatic light-emitting LED chips such as a light-emitting LED chip that emits light in a wavelength range from blue to near ultraviolet. In micro-LED, each individual LED chip serves as a display functional layer. In the method using monochromatic light-emitting LED chips, a wavelength conversion layer (for example, a dispersion of quantum dots or phosphors) that converts the emission wavelength to any one of red, green, and blue is laminated on each of the plurality of monochromatic light-emitting LED chips to realize color display. Organic EL is an abbreviation for Organic Electroluminescence. An organic EL display device is a display device that uses the light emission due to the recombination of electrons and holes injected into an organic compound as a display functional layer. An organic EL display device is roughly classified into a method using three types of light-emitting layers that emit red, green, and blue light, and a method that combines a color filter with a white light-emitting layer that emits white light. In liquid crystal display devices, micro-LEDs, and organic EL display devices, in all cases, the linearity of the light emitted from the display functional layer toward the pixel aperture was not sufficiently obtained. Therefore, stray light (oblique emitted light) occurred with respect to adjacent pixels, resulting in a decrease in display contrast.

[0008] In particular, as the pixel size becomes finer, a decrease in display contrast due to stray light becomes a problem. Also, when the display device is used in a bright environment, a decrease in display contrast due to incident light incident on the display device from the outside also becomes a problem. In organic EL display devices and micro-LEDs, a circular polarizing plate is used to avoid a decrease in contrast caused by incident light incident on the display device from the outside. In organic EL display devices and micro-LEDs, the circular polarizing plate is mounted on the upper surface of the display device for the purpose of eliminating the reflection of external light on the pixel electrode having light reflectivity and improving visibility. However, since the circular polarizing plate is expensive, there is a strong demand for omitting the circular polarizing plate in terms of the structure of the display device.

[0009] Patent Document 1 discloses a two-layer black matrix (see FIG. 1 of Patent Document 1). However, the technology of Patent Document 1 is a technology for displaying a stereoscopic image for a naked-eye observer. Patent Document 1 does not regard a decrease in contrast in a display device using various display functional layers as a problem. Patent Document 1 does not propose a configuration for omitting an expensive circular polarizing plate, and in addition, does not disclose a technology for suppressing surface reflection of the black matrix.

[0010] Patent Document 2 describes a color filter using a first light-shielding layer and a second light-shielding layer. However, Patent Document 2 does not propose a configuration that omits an expensive circular polarizing plate, and in addition, does not disclose a technique for suppressing surface reflection of the first light-shielding layer. Patent Document 2 does not consider a configuration without a color filter. In a micro LED including a red light-emitting element, a green light-emitting element, and a blue light-emitting element, or in a mini LED using a red light-emitting element, a green light-emitting element, a blue light-emitting element, and a liquid crystal layer, the color filter can be omitted. Similarly, an organic EL display device with improved color purity does not require a color filter. Also, in a liquid crystal display device, in a field sequential type that sequentially turns on the red light emission, green light emission, and blue light emission of an LED backlight for display, the color filter can be omitted.

[0011] However, in Patent Document 2, the feature that the second light-shielding layer covers the end portion of the colored layer and the feature regarding the width of the second light-shielding layer in claim 3 are substantially the same as the color filter shown in FIG. 16 of Patent Document 1. Patent Document 1 also describes the problem of alignment between the first light-shielding layer and the second light-shielding layer. The techniques from

[0034] to

[0036] regarding the second light-shielding layer of Patent Document 2 are also described in, for example, paragraph

[0105] of Patent Document 1. Neither Patent Document 1 nor Patent Document 2 discloses or suggests a technique for improving visibility by a light-scattering layer and reflecting the emitted light from a light source such as a backlight or an LED light-emitting element back to the light source side and reusing it at the black matrix portion.

Prior Art Documents

Patent Documents

[0012]

Patent Document 1

Patent Document 2

[0013] Fig. 10 shows a conventional example of a display device including a direct-lit backlight unit 55 having a blue LED as a light-emitting element 51. In this conventional example, a liquid crystal panel 50 is illustrated as a display function portion above the direct-lit backlight unit 55. The liquid crystal panel 50 is provided with a color filter including black matrix Pixels a, b, c, d, and e are schematically shown in the liquid crystal panel to indicate pixel positions.

[0014] The direct-lit backlight unit 55 includes a plurality of light-emitting elements, a diffusion plate 52, a wavelength conversion sheet 53, and, for example, two orthogonal prism sheets 54 on the arrangement of the light-emitting elements. The light-emitting elements are often arranged with a plurality of LED chips individually packaged in a metal housing. The wavelength conversion sheet is for converting a part of the blue light emission of the light-emitting element into red and green light to obtain three colors of red, green, and blue.

[0015] On the light-emitting portions of these LED chips, it is common to fill a phosphor or light-scattering particles together with a silicone resin. Since the light emission of the LED is highly linear and is the light emission near the center of the LED chip, one role of these phosphors and light-scattering particles is to scatter light for expanding the viewing angle. However, in the configuration in which such packaged LED chips are arranged in the backlight unit, the emitted light from the LED chips is scattered, and the contrast is reduced due to the diffusion before the emitted light reaches the color filter provided in the pixel aperture, which is not preferable. In other words, it is difficult to obtain a sufficient effect when applying local dimming.

[0016] Both the diffusion plate 52 and the wavelength conversion sheet scatter light. For example, the emitted light of the c-LED (blue LED) located directly below the c pixel not only enters the c pixel but also leaks into adjacent pixels such as a, b, d, and e in the vicinity, further reducing the effect of local dimming. Not only in liquid crystal display devices but also in LED displays called micro-LEDs, the problem of contrast reduction due to such light scattering or stray light to adjacent pixels has not been solved.

Summary of the Invention

Problems to be Solved by the Invention

[0017] The present invention has been made in view of the above-described background art and problems, and in display devices such as liquid crystal display devices, micro LEDs (LED displays), and organic EL display devices that are further required to have high definition, it improves display contrast and provides a black matrix substrate capable of improving the brightness of the display and a display device including the black matrix substrate.

Means for Solving the Problems

[0018] The black matrix substrate according to the first aspect of the present invention has, on one surface of a transparent substrate, A dispersion of carbon black, transparent fine particles, and a resin a transmittance adjustment layer, a first black matrix having a plurality of openings defined by a line width Ax in a first direction and a line width Ay in a second direction in a plan view, a light scattering layer covering the plurality of openings and the first black matrix, and on the light scattering layer, a second black matrix having a plurality of openings defined by a line width Bx in the first direction and a line width By in the second direction and partitioned so as to overlap at the centers of the line widths Ax and Ay of the first black matrix, and a light-reflective matrix having a plurality of openings defined by a line width Cx in the first direction and a line width Cy in the second direction and partitioned so as to overlap at the centers of the line widths Bx and By on the second black matrix and and includes at least a black matrix substrate in which the line widths Ax, Cx, Ay, and Cy satisfy the relationships of the following formulas (1) and (2). Ax > Bx ≧ Cx ··· (1) Ay > By ≧ Cy ··· (2) of the present invention The light scattering layer included in the configuration of the black matrix substrate can be a light scattering layer containing optically isotropic transparent particles.

[0019] The light scattering layer included in the configuration of the black matrix substrate of the present invention can be a light scattering layer containing zinc oxide particles. The light-scattering layer included in the configuration of the black matrix substrate of the present invention can be a light-scattering layer containing carbon black and a blue pigment. The light-scattering layer included in the configuration of the black matrix substrate of the present invention can be a light-scattering layer containing an ultraviolet absorber. The light-reflective matrix included in the configuration of the black matrix substrate of the present invention can be configured such that a two-layer structure of a thin film of titanium or titanium nitride and a thin film of an aluminum alloy added with neodymium is laminated on the second black matrix. The light-reflective matrix included in the configuration of the black matrix substrate of the present invention can be a black matrix substrate having a three-layer structure in which a thin film of a first conductive oxide, a thin film of silver or a silver alloy, and a thin film of a second conductive oxide are laminated on the second black matrix.

[0020] The black matrix substrate according to the first aspect of the present invention can be configured such that a first transparent resin layer is inserted between the light-scattering layer and the second black matrix. The black matrix substrate according to the first aspect of the present invention can have a second transparent resin layer laminated on the light-reflective matrix. The display device according to the second aspect of the present invention can be a display device including the black matrix substrate according to the first aspect and at least a display function layer. The display device according to the second aspect of the present invention can have the display function layers as a red light-emitting element, a green light-emitting element, and a blue light-emitting element each driven by a thin film transistor. The display device according to the second aspect of the present invention can have the display function layers as a red light-emitting diode, a blue light-emitting diode, and a green light-emitting diode each driven by a thin film transistor.

[0021] The display device according to the second aspect of the present invention can have the display function layer as a liquid crystal layer driven by a thin film transistor, and can include a plurality of optical modules each including a red light-emitting diode, a blue light-emitting diode, and a green light-emitting diode as a backlight unit.

[0022] The light-emitting element (or light-emitting diode) preferably employed in the present invention is a light-emitting element with directivity. For example, in a light-emitting element in which LED chips of red, green, and blue are respectively mounted in individual housings, a light-emitting element in which light-scattering particles or wavelength-converting phosphors are not laminated on the LED chips in the housings is preferable.

Advantages of the Invention

[0023] The present invention can provide a black matrix substrate with high display quality when used as a display device, and a display device including the same, while having a simple configuration.

Brief Description of the Drawings

[0024]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Embodiments for Carrying Out the Invention

[0025] Hereinafter, embodiments 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 denoted by the same reference numerals, and the description thereof is omitted, simplified, or described only when necessary. In each figure, the dimensions and ratios of the components are appropriately different from the actual ones in order to make the components recognizable on the drawing. Also, if necessary, elements that are difficult to illustrate, such as the configuration of a thin film transistor, etc., and the structure of a plurality of layers constituting a conductive layer, the illustration of wiring connections to a circuit portion, switching elements (transistors), etc., and some illustrations are omitted.

[0026] In each of the embodiments described below, characteristic parts will be described, and for example, the description will be omitted for parts where there is no difference between the components used in a normal display device and the display device according to the present embodiment.

[0027] Ordinal numbers such as "first" and "second", like the first black matrix, the second black matrix, the first substrate, the second substrate, and the third substrate, are used to avoid confusion between components and do not limit the quantity. Also, the matrix arrangement of light-emitting elements refers to an arrangement in which light-emitting units each containing one or more light-emitting elements are arranged in a matrix at a certain pitch in a plan view. 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 certain pitch, may be referred to as an optical module. It is desirable to also dispose thin-film transistors for driving the light-emitting elements and light-emitting units on the substrate. When the display functional layer is a liquid crystal layer, this optical module is called a direct-type backlight. The light-emitting unit may be surrounded by partition walls in a grid pattern in a plan view when used as a display device. The light-emitting unit surrounded by partition walls in a grid pattern in a plan view contains one or more light-emitting elements that are light-emitting diodes. In the following drawings (cross-sectional views), when one light-emitting element is illustrated within the partition wall, it is assumed that a plurality of light-emitting elements are disposed within this partition wall. In a display device using the local dimming technology described later, the on / off driving and the light emission brightness can be adjusted, for example, in units of light-emitting units each containing one or more light-emitting elements, or in a plurality of light-emitting units. Note that in the local dimming technology, the number of light-emitting elements included in the light-emitting unit in a plan view and the number of pixels can have more pixels. In other words, the efficient driving of the display device due to the smaller number of light-emitting elements compared to the number of pixels can be an advantage of local dimming. Note that the partition walls in a matrix (grid) pattern in a plan view can reduce the adverse effect of stray light on adjacent pixels, for example, compared to stripe-shaped partition walls.

[0028] Note that in the description of the present invention, in a configuration where the black matrix substrate and the optical module are bonded to face each other, for example, an array substrate on which a liquid crystal layer and thin-film transistors for driving the liquid crystal are arranged is included in a configuration inserted between the black matrix substrate and the optical module. In this configuration including the liquid crystal layer, the optical module serves as a direct-type backlight unit.

[0029] The term "planar view" described in the specification may refer to the "planar view" seen from one side of the transparent substrate and the "planar view" seen in the normal direction from the second side of the transparent substrate (the side opposite to the first side). Alternatively, for the description of the light-reflective matrix and the partition structure described later, it may be the "planar view" seen from the film surface of the light-reflective matrix.

[0030] In an embodiment of the present invention, for the "display function layer" provided in the display device, any one of a plurality of light-emitting diode elements called LEDs (Light Emitting Diodes), a plurality of organic EL (organic electroluminescence) elements also called OLEDs (Organic Light Emitting Diodes), or a liquid crystal layer can be used. LEDs, LED chips, and light-emitting diode elements may simply be referred to as light-emitting elements in the following description.

[0031] Note that the openings of the first black matrix or the second black matrix related to the present invention, or some of the light-emitting elements (light-emitting diodes), overlap with the center lines at the center positions respectively.

[0032] An LED is a light-emitting diode (Light Emitting Diode), and 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 gallium indium phosphide (AlGaInP) are applied to the LED. The blue light-emitting diode described later as a single-color light-emitting LED mainly uses gallium nitride (GaN). The light-emitting diode element applied to the present invention is preferably a blue light-emitting diode having a light-emitting peak wavelength of 430 nm or more and 460 nm or less. The blue light-emitting diode may include light emission in the near-ultraviolet region such as 365 nm, 385 nm, and 395 nm.

[0033] In the case of mini-LEDs, for example, LED chips with a size of 40 μm to 200 μm can be used. In the case of micro-LEDs, for example, LED chips with a size of 2 μm to 60 μm can be used. As for the structure of the LED chip, a horizontal LED in which the n-side electrode and the p-side electrode are on the same side may be used, but a vertical LED in which the n-side electrode and the p-side electrode are on different surfaces (opposite parallel surfaces) in the thickness direction of the LED can also be used. In the following description, the upper electrode and the lower electrode refer to either the n-side electrode or the p-side electrode of the vertical LED. (First Embodiment) [Transparent Substrate] As the material of the transparent substrate (first transparent substrate) 100 applicable to the black matrix substrate 110 of the present invention, a transparent substrate such as a glass substrate, a quartz substrate, a sapphire substrate, or a plastic substrate including a polyimide film can be used. In addition, when the display function layer and the array substrate in which a plurality of thin film transistors for driving the display function layer are arranged in a matrix and the black matrix substrate 110 are bonded together to form a display device, it is preferable that the substrate materials of the array substrate and the black matrix substrate are the same.

[0034] In addition, the second substrates 200 and 300 in which a plurality of light emitting elements are arranged in a matrix, as shown in FIGS. 5 and 6, may be the same as the material of the transparent substrate 100, but may also be a substrate colored black or other colors. The second substrates 200 and 300 may be sapphire substrates, or may be silicon substrates on which CMOS elements (such as transistors) are arranged. It may also be a silicon substrate on which LED elements (light emitting elements) grown by crystal growth are arranged via a buffer layer. The mounting of the light emitting elements 24 (blue LED 21, green LED 22, red LED 23) may be 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. A plurality of thin film transistors for driving the LED elements or the liquid crystal layer may be arranged on the second substrate. [Transmittance Adjustment Layer] As will be described later, the transmittance adjustment layer is a layer formed on one surface of the transparent substrate, which has the role of adjusting the transmittance for improving visibility and reducing the reflectance accordingly. The transmittance adjustment layer 2 is at least a dispersion of carbon black, transparent fine particles, and a resin. The transmittance adjustment layer 2 is a resin dispersion containing carbon black as a main pigment, and it is preferable that the transmittance of the transmittance adjustment layer 2 for visible light is in the range of 70% or more and 99.7% or less. From the perspective of this transmittance, the addition amount of carbon black to the resin dispersion is adjusted.

[0035] In a micro-LED or an organic EL display device, it is often the case that a light-reflective electrode is provided below an LED or an organic EL layer which is a light-emitting element. In such a micro-LED or an organic EL display device having such a structure, the re-reflected light of external incident light by the light-reflective electrode enters the observer's eyes and reduces the visibility. In a micro-LED or an organic EL display device, usually, in order to eliminate the re-reflected light of external incident light, an expensive circular polarizing plate is used in combination with the display device. The visible light transmittance of the circular polarizing plate is about 50%.

[0036] The transmittance adjustment layer 2 according to the present invention has two roles. The first is to suppress the re-reflected light of external incident light by the above-described light-reflective electrode. By setting the transmittance of the transmittance adjustment layer 2 in the range of 70% or more and 99.7% or less, the re-reflected light of external incident light is suppressed. Such adjustment of the transmittance of the transmittance adjustment layer can be easily realized by setting the addition amount of carbon black, which is a black pigment, within the range of, for example, 0.2 wt% to 8 wt% with respect to the resin solid content. When the addition amount of carbon black exceeds 9 wt%, and further exceeds 10 wt%, the transmittance of the transmittance adjustment layer decreases too much.

[0037] In addition, by disposing the scattering film 2 having a light scattering function on the black matrix substrate 110, it is possible to eliminate the specular reflection component of the reflected light of the externally incident light (the specular reflection light does not enter the observer's eyes). The second role of the transmittance adjustment layer 2 according to the present invention is to reduce the reflectance of the first black matrix. The reduction of the reflectance of the first black matrix will be described below with reference to FIGS. 11 and 12. In addition, it will be described in more detail in the following embodiments. The reduction of the reflectance of the first black matrix can be easily realized by inserting a transmittance adjustment layer at the interface between a transparent substrate such as glass and the first black matrix using the coating liquid on the dilute side of the above carbon black addition (for example, 0.2 wt% to 2 wt%).

[0038] FIG. 11 shows the reflectance when the transmittance adjustment layer according to the present invention is disposed at the interface between a transparent substrate such as glass and a black matrix (first black matrix). FIG. 12 shows the reflectance at the interface between a transparent substrate and a black matrix having a conventional configuration. As shown by the reflectance BL1 in FIG. 11 and the reflectance BL2 in FIG. 12, a low reflectance can be obtained by disposing the transmittance adjustment layer. By further adding a small amount of blue pigment to the transmittance adjustment layer, the transmittance (on the red side) at wavelengths of 600 nm or more of light can be further reduced.

[0039] Assuming external light is incident on the display surface, the external light passes through the transmittance adjustment layer 2 once, is then reflected by the light-reflective electrode, and then passes through the transmittance adjustment layer 2 again and is emitted to the observer side. The external light reflection can be sharply reduced by this double passage of light. If the visible light transmittance of the transmittance adjustment layer 2 is 70% or more, and assuming the emission light intensity from a light-emitting element such as an LED is equivalent to that of a display device using a circular polarizing plate, the display device according to the present invention can provide a brighter display.

[0040] In addition, in many liquid crystal display devices, two polarizing plates with crossed Nicol (the polarization axes are orthogonal) are used. When using such a circular polarizing plate or polarizing plate, for the purpose of improving dispersibility or reducing the refractive index of the semi-transmissive film, optically isotropic fine particles that do not cause polarization deviation and are transparent in the visible region can be added to the transmittance adjustment layer.

[0041] For example, when 2 is a transparent inorganic film or a resin film with a visible light transmittance close to 100%, ripples due to interference may occur in the light reflection at the interface with the first black matrix 1, and the first black matrix 1 may be slightly colored and observed. Such slight coloring caused by the reflected light is likely to be observed during black display with the display device turned off. Also, in such cases, it may look iridescent when viewed from an oblique direction from the observer, and the visibility is likely to decrease.

[0042] On the other hand, by using silica fine particles and carbon black in combination to form the transmittance adjustment layer 2, an effect of reducing the size of such ripples can be obtained. From the above viewpoints, the transmittance adjustment layer 2 containing transparent fine particles in the visible region is useful. The same effect can be obtained even when low-concentration carbon black is included without including silica fine particles. The particle size of transparent particles such as silica fine particles is not specified, but for example, transparent particles with an average primary particle size of 3 nm to 100 nm can be applied. The film thickness of the transmittance adjustment layer is preferably in the range of 0.1 μm to 1 μm, for example, but a film thickness of 1 μm or more is also acceptable.

[0043] When the transmittance adjustment layer is formed using an organic pigment as the main pigment component, the reflected light of external light at the interface with the first black matrix may appear yellowish. In contrast, the transmittance adjustment layer 2 containing carbon black as the main pigment component has a substantially flat reflected light and hardly colors. That the reflected light is flat means that in the visible range of the light wavelength from 400 nm to 700 nm, for example, in a small range such as 50 nm, there are no irregularities (fluctuations) in the transmittance of 2% or more, and a transmittance curve close to a straight line can be obtained. In other words, when the visible range from 400 nm to 700 nm is divided in 50 nm units, the magnitude of the reflectance variation (ripple) within that 50 nm unit can be made 1.0% or less. Also, in the visible range of the light wavelength from 400 nm to 700 nm, the reflectance at the interface with the first black matrix can be within the range of 0.01% or more and 1.0% or less. Note that the reflectance variation (ripple) is the difference between the valleys of the reflectance spectral curve within the above-described 50 nm unit of the reflectance measured in the visible range of the light wavelength from 400 nm to 700 nm, but for a simple evaluation, the value of the reflectance peak within the 50 nm unit may be used. In the latter simple evaluation, the value of the apparent reflectance variation becomes a larger value.

[0044] The reflectance here is the reflectance measured through the transparent substrate and the transmittance adjustment layer with the reflectance of the aluminum film as the reference (100%). The measurement can be easily performed using, for example, a microscopic spectrophotometer. Here, optically isotropic transparent fine particles play an important role in suppressing reflectance variation. For the purpose of further suppressing the effect of reflectance variation and reducing the reflectance, a transmittance adjustment layer containing a small amount of carbon black and blue pigment together with the transparent particles in the resin may also be used.

[0045] The resin only needs to be able to impart necessary reliability such as heat resistance as the transmittance adjustment layer 2. An alkali-developable photosensitive resin may be used, or a thermosetting resin may be used. As the thermosetting resin, for example, it can be a resin containing an epoxy group or resin, or a resin having at least one group selected from a methylol group, an alkoxymethyl group, or an acyloxymethyl group. These resins are used as a coating solution dispersed with transparent particles and an organic solvent, applied onto a transparent substrate, and finally cured to form the transmittance adjustment layer 2. [Black Matrix] The first black matrix and the second black matrix according to the present invention (hereinafter sometimes simply referred to as the black matrix) can be used by dispersing a black pigment having a visible light absorption function such as carbon black in a resin.

[0046] In the black matrix substrate according to the present invention, a configuration is proposed in which a metal thin film such as aluminum is used as a light-reflective matrix described later. Metal thin films such as aluminum have high light-shielding properties. By setting the film thickness of the light-reflective matrix to, for example, a film thickness of 0.15 μm or more and 0.8 μm or less it is possible to eliminate light transmission in the film thickness direction. Therefore, a high light-shielding property is not required for the black matrix according to the present invention. In terms of optical density OD, for example, a range of 2 or more and 3 or less is sufficient. It may be 4 or more in optical density, but this will increase the process load such as exposure time. When the optical density is 1 or less, it is easy to visually recognize the reflection of external light from a metal thin film such as aluminum, which may lead to a decrease in the image quality of the display device. The concentration of black pigment such as carbon black and its film thickness can be set to a carbon black concentration that can be within the above range of optical density.

[0047] The features related to the above black matrix are common to the first black matrix and the second black matrix. The first black matrix and the second black matrix are each a lattice pattern in plan view, and overlap with the center of the line width in the first direction (X direction) and the second direction (Y direction) respectively. In other words, the center positions of the plurality of openings in plan view also overlap. By making the patterns of the first black matrix and the light-reflective matrix described later into lattice patterns that partition the openings, it is possible to reduce the stray light influence on adjacent pixels in the first direction (X direction) and the second direction (Y direction) and improve the display quality. When both of the matrix patterns are stripe patterns, stray light is likely to have an adverse effect on adjacent pixels in the extension direction of the stripe pattern. Color filters such as blue, green, and red may be disposed in the openings of the black matrix as necessary. [Diffusion film] In the present invention, as shown in FIG. 1, FIG. 4, etc., a light-scattering layer 10 can be disposed. The light scattering layer 10 is basically a dispersion of a transparent resin and transparent particles 8. As described above, for the transparent particles 8, for example, transparent particles with an average particle size of 1 μm or more and 3.0 μm or less can be applied. As the transparent particles 8, optically isotropic transparent particles can be used. "Optically isotropic" means that the transparent particles applied to the embodiments 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 without being affected by the crystal axis or crystal structure. The silica particles have an amorphous structure (amorphous). As particles of resins such as resin beads, particles having various properties including refractive index are known, and these particles can be used in combination. Particles of resins such as acrylic resin, polystyrene, polyurethane, nylon, melamine resin, and benzoguanamine resin may be used in combination. For the light scattering layer 10, for example, it is preferable to use light scattering particles having a size in the micron unit with an average particle size of 1.0 μm or more and 3.0 μm or less. That is, by using particles having a particle diameter larger than the wavelength of visible light, it is easy to obtain appropriate light scattering properties as the scattering film 10. Further, transparent fine particles with an average particle size of around 0.2 μm or 0.1 μm or less may be used in combination from the viewpoint of a dispersion aid. The above transparent particles 8 and transparent fine particles can be dispersed in a transparent resin or a resin containing an ultraviolet absorber to form the light scattering layer 10. Transparent particles and transparent fine particles of zinc oxide that are transparent in the visible region and can absorb ultraviolet rays of 390 nm or less can also be used. In the description of the present invention, particles with an average primary particle size of 1 μm or more are regarded as transparent particles, and particles with an average primary particle diameter of 0.2 μm or less are regarded as transparent fine particles.

[0048] Examples of the ultraviolet absorber include benzophenone-based compounds, benzotriazole-based compounds, and triazine-based compounds. The ultraviolet absorber preferably has a phenolic hydroxyl group. By providing a phenolic hydroxyl group, crosslinking with a compound having an alkoxymethyl group or a methylol group during heat treatment becomes possible. By crosslinking, bleeding out of the ultraviolet absorber during long-term storage after hard coating can be suppressed, and reliability can be improved. The addition amount of the ultraviolet absorber can be, for example, 0.05% by mass or more and 10% by mass or less based on the solid content of the transparent resin.

[0049] The thickness of the light-scattering layer 10 is a dispersion of transparent particles 8 larger than the wavelength of light, and in this relationship, it can be set to 1 μm or more and 50 μm or less. It can also be formed thicker than 50 μm, but the improvement in scattering properties by making it thicker than 50 μm is small. Rather, forming it thickly tends to waste the process load, such as the working time for coating and drying.

[0050] Light scattering does not necessarily have to be limited to only the dispersion of transparent particles in a transparent resin. For example, by using a dispersion liquid in which two types of resins with different refractive indices are dissolved in an organic solvent or the like, and applying and drying it, phase separation of the two types of resins can be performed to impart light scattering properties.

[0051] In a display device that does not use a circular polarizing plate or a polarizing plate, it is not necessary for the transparent particles 8 to be optically isotropic, and the selection range of the transparent particles 8 can be widened. For example, zinc oxide particles can be used as the transparent particles 8 that can be added to the scattering film 10. Zinc oxide has a high transmittance in the visible region from 400 nm to 700 nm and can absorb ultraviolet light of 390 nm or less. From this perspective, it is meaningful to use zinc oxide transparent particles or transparent fine particles in a display device that does not use a circular polarizing plate.

[0052] An ultraviolet absorber can be further added to the transmittance adjustment layer 2 and the light-scattering layer 10 described later. Many of the phosphors and quantum dots used in the wavelength conversion layer are likely to be excited to generate secondary light by light in the short wavelength region. This may cause light emission that is not intended on the screen of an LED display such as a micro LED due to strong external light incidence such as sunlight, resulting in a decrease in visibility. In order to suppress light emission that is not intended for the wavelength conversion layer by external light, an ultraviolet absorber can be added to the transmittance adjustment layer 2 and the light-scattering layer 10. In addition, the ultraviolet absorber added to the light-scattering layer 10 can absorb ultraviolet light when the light emitted from a light-emitting element such as a blue LED contains ultraviolet light, preventing it from entering the observer's eyes.

[0053] Furthermore, when using light-scattering particles (transparent particles) with an average particle size of 1.0 μm or more and 3.0 μm or less in micron units for light scattering, the surface unevenness of the light-scattering layer 10 becomes large, and it is necessary to flatten it. That is, the light-scattering layer 10 according to the present invention can have a laminated structure with the transmittance adjustment layer 2 as a flattening film in a resin layer containing an ultraviolet absorber. [Light-reflective matrix] The light-reflective matrix 5 has a structure in which a metal thin film having light reflectivity is superimposed on one surface of the black matrix and laminated in a lattice pattern similar to that of the black matrix. As described above, a metal thin film of aluminum or an aluminum alloy has high light-shielding properties when the film thickness exceeds 0.1 μm. Also, a metal thin film of aluminum or an aluminum alloy has a high light reflectance. The light-reflective matrix 5 according to the present invention utilizes this light reflection to return the light emitted from a light source such as a light-emitting diode back to the light source side for reuse.

[0054] With the increasing high definition of liquid crystal display devices and LED displays, the area ratio of the black matrix to the aperture area is increasing. With high definition of 600 ppi, 800 ppi, and further 1000 ppi or more, the black matrix area ratio exceeds 60% and in some cases exceeds 70% (the aperture area ratio decreases). The present invention proposes a configuration in which a light-reflective matrix is disposed on the back surface of the second black matrix facing the first black matrix (the surface opposite to the first black matrix). FIG. 4 is a cross-sectional view showing a state where light L6 emitted from a light source such as a direct-lit backlight unit or a light-emitting diode is reflected by the light-reflective matrix 5 and the reflected light L7 returns to the light source side. FIG. 7 is a cross-sectional view of a direct-lit backlight unit 510 in which light-emitting diodes 21, 22, and 23 are disposed.

[0055] The light reflected in this way (for example, L7) is the reflective electrode 18 and the partition wall 28 shown in FIG. 7. Alternatively, it reflects again when hitting various members such as light-emitting diodes. By utilizing the reflected light, it is possible to contribute to improving the brightness of the display device. As described above, blue light is easily absorbed by reflection or scattering, and by repeating the reflection, the display tends to have a yellowish tint. Adding a blue pigment to the resin layer on the black matrix substrate side, such as the light scattering layer 10, the transmittance adjustment layer, and the first transparent resin layer, for the purpose of weakening the yellowish tint is also useful from this perspective. In addition, a light-reflective metal thin film, a reflection-enhancing film, or a reflective sheet may be separately installed in the direct-lit backlight unit.

[0056] FIG. 4 shows a situation where light L1 incident on the scattering film 10 from an oblique direction repeatedly reflects and has an adverse effect as light L5 (stray light) on the adjacent pixel P2. Such illustration, the lateral diffusion of light is improved by dispersing carbon black and a blue pigment together in the light scattering layer 10 of the scattering functional portion or the transmittance adjustment layer 2 that also serves as an ultraviolet absorption functional portion. The light absorption by the two layers of the first black matrix 1 and the second black matrix 4 also improves the adverse effect of stray light.

[0057] FIGS. 1 and 4 are cross-sectional views of a black matrix substrate including illustrations of the first black matrix 1, the second black matrix 4, and the light-reflective matrix 5. FIG. 3 is a plan view of FIG. 1 as viewed from the B direction (the direction from the light-reflective matrix 5). The illustration of the scattering film 10 is omitted. It is preferable to form the first black matrix 1 and the second black matrix 4, or the line width of the first black matrix, wider than the line width of the light-reflective matrix 5. When the second black matrix 4 is not provided, the light-reflective matrix 5 may be visually recognized obliquely from the direction of the observer 20 (the direction indicated by Z). When the light-reflective matrix 5 is visually recognized by the observer 20, the display quality of the display device is deteriorated. In order to improve the visibility from an oblique direction, the second black matrix 4 is provided, but when the line width Ax of the first black matrix 1 is sufficiently wider than the line width Cx of the light-reflective matrix 5, the formation of the second black matrix 4 may be omitted. When the line width Ax of the first black matrix 1 is wider than the line width Cx of the light-reflective matrix 5, the line width Bx of the second black matrix 4 and the light-reflective matrix line width Cx may be made equal. Summarizing the above-described relationship of the line widths, the following relationship holds. Ax > Bx ≧ Cx ····· (1) Ay > By ≧ Cy ····· (2) As the aluminum alloy, an aluminum alloy to which a small amount of a high melting point metal such as Mo or Ti, Si, or a rare earth such as Nd (neodymium) is added can be adopted. From the viewpoint of reflectance, an aluminum alloy containing 0.2 mass% or more and 3 mass% or less of Nd (the balance being inevitable impurities) is preferable. When Nd is less than 0.2 mass%, the crystals of aluminum tend to coarsen or hillocks are formed, resulting in a decrease in reflectance. Also, when Nd exceeds 3 mass%, the reflectance tends to decrease. In the range of 0.2 mass% or more and 3 mass% or less of Nd, a high reflectance can be stably reproduced easily.

[0058] Note that silver or a silver alloy may be used as the metal thin film of the light-reflective matrix 5. Since silver and silver alloys have low adhesion, a configuration in which they are sandwiched between conductive oxides containing indium oxide, zinc oxide, or the like can be applied. Note that a light-scattering element such as a second light-scattering layer may be laminated on the light-reflective matrix.

Example

[0059] <Example 1> Using FIGS. 1 and 3, Example 1, which is a black matrix substrate, will be described. FIG. 1(a) is a cross-sectional view of the black matrix substrate 110 of Example 1. The black matrix substrate 110 has a structure in which a transmittance adjustment layer 2, a first black matrix layer 1, a light scattering layer 10, a second black matrix layer 4, and a light reflective matrix 5 are laminated in this order on a transparent substrate 100. The light scattering layer 10 has a light scattering function of dispersing transparent particles 8. The light scattering layer 10 can be a two-layer structure of a first transparent resin layer 3 in which an ultraviolet absorber is dispersed in a resin. An ultraviolet absorber may be added or dispersed also in the light scattering function portion.

[0060] A transparent resin layer can be laminated on the black matrix substrate 110 so as to cover the light reflective matrix 5. The thickness of the transparent resin layer may be important when the black matrix substrate according to the present invention is applied to a liquid crystal display device.

[0061] The direction indicated by the arrow C in FIG. 1 indicates the irradiation direction of light from a light source which is a light emitting element such as an LED. FIG. 1(d) is an enlarged view and a cross-sectional view of the light reflective matrix 5. On the second black matrix layer 4, a two-layer structure of a metal thin film 6 of titanium or titanium nitride and a thin film 7 of aluminum or an aluminum alloy is laminated. The film thicknesses of these metal thin films 6 and thin film 7 are not limited. For example, the metal thin film 6 can be formed with a film thickness of 100 nm to 300 nm, and the thin film 7 can be formed with a film thickness of 10 nm to 40 nm.

[0062] FIG. 1(c) is an enlarged view of the first black matrix layer 1 formed on the transmittance adjustment layer 2. FIG. 3 is a plan view of FIG. 1(b) as viewed from the C direction (the direction from the light reflective matrix 5). The illustration of the scattering film 10 is omitted.

[0063] <Example 2> FIG. 2(a) is a cross-sectional view of the black matrix substrate 120 of Example 2. Similar to Example 1, the black matrix substrate 120 has a structure in which a transmittance adjustment layer 2, a first black matrix layer 1, a light scattering layer 10, a second black matrix layer 4, and a light reflective matrix 39 are laminated in this order on a transparent substrate 100. The light scattering layer 10 has a light scattering function in which transparent particles 8 are dispersed in a transparent resin. The light scattering layer 10 can be a two-layer structure of a first transparent resin layer 3 in which an ultraviolet absorber is dispersed in the resin. An ultraviolet absorber may also be added or dispersed in the light scattering function portion.

[0064] The light reflective matrix 39 shown in the partial enlarged view of Fig. 2(b) has a three-layer structure of a thin film 36 of a first conductive oxide, a thin film 37 of silver or a silver alloy, and a thin film 38 of a second conductive oxide on the second black matrix layer 4. The first conductive oxide and the second conductive oxide are conductive oxides containing 50 wt% or more of indium oxide. The film thicknesses of the first conductive oxide and the second conductive oxide can each be in the range of 10 nm to 60 nm, but may be more than 60 nm. The first conductive oxide and the second conductive oxide may each have a different film thickness. The film thickness of 37 can be in the range of 100 nm to 300 nm, but may be more than 300 nm. The thin film of silver or a silver alloy has a higher reflectance than the thin film of aluminum and can be preferably used. In addition to indium oxide, the first conductive oxide and the second conductive oxide can be composite oxides added with metal oxides such as zinc oxide, tin oxide, antimony oxide, and titanium oxide. (Second Embodiment) The second embodiment is an application of the black matrix substrate of the present invention to a display device such as an LED display or a liquid crystal display device. Hereinafter, Examples 3 and 4 of the second embodiment will be described in detail.

[0065] <Example 3> The present embodiment will be described with reference to FIGS. 5, 7, and 9. FIG. 5 is a cross-sectional view of an LED display formed by bonding a black matrix substrate 110 of Embodiment 1 and an array substrate 210 on which red LEDs 21, green LEDs 22, and blue LEDs 23 are mounted so as to face each other. The black matrix substrate 110 and the array substrate 210 are bonded via, for example, a silicone-based resin.

[0066] The array substrate 210 having a matrix arrangement of light-emitting units may be referred to as an optical module in the following description. Each light-emitting unit includes a plurality of light-emitting elements, namely, red LEDs 21, green LEDs 22, and blue LEDs 23.

[0067] In Embodiment 2, the total number of light-emitting elements is arranged in accordance with the pixel pitch at a number that is 1 / 3 of the total number of pixels for each. At least two thin-film transistors are respectively arranged in one pixel. The light-emitting elements (red LED 21, green LED 22, blue LED 23) can be separated by a partition wall 28 or the like. The light from the light-emitting elements corresponding to the light-reflective matrix 5 is reflected on the light source (light-emitting element) side and reused.

[0068] Each light-emitting element can have a structure as shown in FIG. 7. For example, the blue LED 23 is mounted on a reflective electrode 18 via a lower electrode 17. The upper electrode 16 of the blue LED 23 is linked to an LED common electrode via a contact hole 15. Note that such mounting of the light-emitting elements may use other mounting techniques such as wire bonding using a gold wire or an aluminum wire instead of taking the configuration of FIG. 7. The array substrate on which the light-emitting elements (red LED 21, green LED 22, blue LED 23) are arranged is called an optical module. For example, the technology proposed in the present invention has the flexibility to provide various display devices by combining a black matrix substrate and optical modules with different specifications.

[0069] In FIG. 7, the thin film transistors are respectively disposed on the fourth insulating layer 41, but the illustration of the thin film transistors is omitted in FIG. 7. FIG. 9 is an equivalent circuit diagram for driving a light emitting element 40 (corresponding to any one of a red LED 21, a green LED 22, and a blue LED 23) with two thin film transistors. Among the two thin film transistors, the selection transistor 45 receives a selection signal from the gate line G9 and a video signal from the source line S9, and drives the drive transistor 46. The drive transistor 46 supplies current from the power supply line VD7 to the light emitting element 40 to cause light emission. In Example 4 described later, instead of driving each light emitting element, it may be driven to change the brightness for each light emitting unit or for each light emitting color within the light emitting unit.

[0070] In the thickness direction of the scattering film 10, the first black matrix 1 and the light-reflective matrix 5 (and the second black matrix 4) are positioned to face each other, so that the influence of stray light on adjacent pixels can be suppressed. In other words, the oblique light incident on adjacent pixels can be reduced. For example, the light Gc emitted in the opening direction shown in FIG. 5 is the light from the green LED 22 emitted as it is. However, the lights GL and GR directed toward adjacent pixels are cut by the light-reflective matrix 5, and the influence on adjacent pixels can be eliminated. The thickness of the scattering film 10, the line width of the black matrix 1 (or pixel aperture ratio), the thickness of the scattering film 10, and the scattering particle density are appropriately adjusted according to the overall size and application of the LED display. A cover glass, a touch panel, and further an antenna for charging or communication may be mounted on the LED display.

[0071] <Example 4> Example 4 will be described with reference to FIGS. 6, 7, and 8. FIG. 6 shows a liquid crystal display device 700 formed by bonding a black matrix substrate 110 described in Example 1 and an array substrate 310 via a liquid crystal layer 30, and disposing a light module 510, which is a backlight unit, below the liquid crystal panel 710. Here, the liquid crystal panel 710 refers to a configuration that does not include the light module 510. In the array substrate 310, at least one thin film transistor for driving liquid crystal is connected to each pixel electrode 26. The liquid crystal layer 30 is of a fringe field switching (FFS) type driven by a fringe electric field between the pixel electrode 26 and the common electrode 17. Note that the liquid crystal is not limited to FFS and may be other liquid crystals such as vertical alignment (VA). FIG. 7 is a partially enlarged view of the light module 510 including a plurality of light emitting units 24.

[0072] The light emitting unit 24 includes a plurality of red LEDs 21, green LEDs 22, and blue LEDs 23 in the light emitting unit 24 partitioned by a partition wall 28. The plurality of red LEDs 21, green LEDs 22, and blue LEDs 23 in the light emitting unit 24 emit light with adjusted intensities of red, green, and blue according to the color and brightness to be displayed in the light emitting unit. For individual driving of the light emitting units, it is desirable that each of the light emitting units be driven by a thin film transistor. The plurality of red LEDs 21, green LEDs 22, and blue LEDs 23 in each light emitting unit can be driven together for each color.

[0073] Although Fig. 7 is simplified for explanation, the number of red LEDs 21, green LEDs 22, and blue LEDs 23 (or the number of blue LEDs 25) in the light-emitting unit 24 is not limited to a total of three. The light-emitting unit 24 is driven by local dimming on a per-unit basis, and the number of pixels to be locally dimmed at this time is also not limited to several hundred to several thousand. The larger the number of target pixels, the lower the cost for forming the light-emitting unit can be. The number (or the number of blue LEDs 25), the arrangement position, and the size of the red LEDs 21, green LEDs 22, and blue LEDs 23 are adjusted so that the pixels to be locally dimmed have a uniform display within the section. The mounting means of the light-emitting elements is also not limited, and flip-chip bonding, wire bonding, or anisotropic conductive film means may be used for mounting. The illustration shows a method of connecting the LED common electrode 14 to the upper electrode via the contact hole 15 as shown in Fig. 7. When the thicknesses of the red LED 21, green LED 22, and blue LED 23 are different, it can be adjusted by the depth of the contact hole and the thickness of the lower electrode, etc.

[0074] Generally, an LED light-emitting element includes an active layer 47 serving as a light-emitting layer between an n-type semiconductor layer and a p-type semiconductor layer of each of the red LED 21, green LED 22, and blue LED 23 in Fig. 7. Most of the light emitted by the active layer 47 is emitted upward through the upper electrode. At this time, a part of the light is emitted laterally from the active layer 47 as shown in the figure. In order to effectively use the lateral light 48, it is preferable to arrange the transparent particles 8 near the active layer 47. The light scattered by the transparent particles 8 is reflected and utilized by the reflective electrode 18 and the partition wall 28.

[0075] In Fig. 6, the illustration of the thin-film transistor is omitted, but the thin-film transistor is disposed on the first insulating layer. FIG. 8 is an equivalent circuit diagram of liquid crystal driving using the array substrate 310 in the liquid crystal panel 710 portion. In the equivalent circuit diagram of FIG. 8, one pixel electrode 26 is electrically associated with one thin film transistor 44, and the liquid crystal layer 30 shown in the liquid crystal display device 710 of FIG. 6 is driven by the thin film transistors provided on the array substrate 310. Receiving the video signal from the source line S and the selection signal from the gate line G8, a liquid crystal driving voltage is applied to the pixel electrode 26, and the liquid crystal layer 30 is driven. Note that the formation of the auxiliary capacitor CS8 and the auxiliary capacitor line CS may be omitted. The third embodiment can provide a simple liquid crystal display device capable of omitting the color filter and the wavelength conversion layer.

[0076] The display device including the black matrix substrate according to the above-described embodiment can be applied in various ways. Examples of electronic devices to which the display device according to the above-described embodiment can be applied include 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 copiers, vending machines, automated teller machines (ATMs), personal authentication devices, optical communication devices, electronic devices such as IC cards, and the like. The above-described embodiments can be freely combined and used. It is desirable that an electronic device equipped with the display device according to the embodiment of the present invention further includes an antenna for performing communication and non-contact power reception and power supply.

[0077] The preferred embodiments of the present invention have been described above, but it should be understood that these are exemplary of the present invention and should not be considered as limiting. Additions, omissions, substitutions, and other changes can be made without departing from the scope of the present invention. Therefore, the present invention should not be regarded as limited by the foregoing description, but is defined by the claims.

Explanation of Reference Numerals

[0078] 1 ··· The first black matrix layer 2 ··· Transmittance adjustment layer 3 ··· The first transparent resin layer 4 ··· The second black matrix layer 5, 39 ··· Light-reflective matrix (metal thin film) 6 ··· Metal thin film of titanium or titanium nitride 7 ··· Thin film of aluminum or aluminum alloy 8 ··· Transparent particles 9 ··· The second transparent resin layer 10 ··· Light-scattering layer 14 ··· LED common electrode 15 ··· Contact hole 16 ··· Upper electrode 17 ··· Lower electrode 18 ··· Reflective electrode 19 ··· Pixel opening 20 ··· Observer 21 ··· Blue LED 22 ··· Green LED 23 ··· Red LED 24 ··· Light-emitting unit 26 ··· Pixel electrode 27 ··· Common electrode 28 ··· Partition wall 29 ··· Prism sheet 30 ··· Liquid crystal layer 31 ··· The first polarizing plate 32 ··· The second polarizing plate 33 ··· The first insulating layer 34 ··· The second insulating layer 35 ··· The third insulating layer 36 ··· Thin film of the first conductive oxide 37 ··· Thin film of silver or silver alloy 38 ··· Thin film of the second conductive oxide 40 ··· Diode (LED) 41 ··· The fourth insulating layer 42 ··· The fifth insulating layer 43 ··· The sixth insulating layer 44 ··· Thin film transistor 45 ··· Selection transistor (thin film transistor) 46 ··· Driving transistor (thin film transistor) 47 ··· Active layer 48 ··· Lateral light 50 ··· Liquid crystal panel 51 ··· Blue LED 52 ··· Diffusion plate 53 ··· Wavelength conversion sheet 54 ··· Prism sheet 100 ··· Transparent substrate 110, 120 ··· Black matrix substrate 200 ··· Second substrate 210 ··· Array substrate 300 ··· Third substrate 310, 320, 330 ··· Array substrate 400 ··· Fourth substrate 410, 510 ··· Optical module 500 ··· Fifth substrate 600, 610 ··· LED display 700 ··· Liquid crystal display device 710 ··· Liquid crystal panel 800 ··· Conventional liquid crystal display device 900 ··· Display functional layer Ax, Ay ··· Line width of the first black matrix Bx, By ··· Line width of the light reflection matrix Cx, Cy ··· Line width of the second black matrix c-LED ··· Light emitting element directly below the c pixel B ··· Irradiation direction of light from the light source L1, L2, L3, L4, L5, L6, L7 ··· Light (incident light, reflected light, stray light, etc.) LB1 ··· Reflectivity in the configuration of the transparent substrate, transmittance adjustment layer, and first black matrix LB2 ··· Reflectivity in the configuration of the transparent substrate and first black matrix CS ··· Auxiliary capacitance line CS8 ··· Auxiliary capacitance VD7 ··· Power supply line G8, G9... gate lines S8, S9... source lines P1... P1 pixels P2... P2 pixels (adjacent pixels)

Claims

1. On one surface of the transparent substrate 1, a transmittance adjustment layer which is a dispersion of carbon black, transparent fine particles, and a resin, a first black matrix having a plurality of openings defined by a line width Ax in a first direction and a line width Ay in a second direction in plan view, a light scattering layer covering the plurality of openings and the first black matrix, on the light scattering layer, a second black matrix having a plurality of openings defined so as to overlap at the centers of the line width Ax and the line width Ay of the first black matrix, and defined by a line width Bx in the first direction and a line width By in the second direction, and on the second black matrix, at least a light reflective matrix having a plurality of openings defined so as to overlap at the centers of the line width Bx and the line width By, and defined by a line width Cx in the first direction and a line width Cy in the second direction, wherein the line widths Ax, Cx, Ay, and Cy satisfy the relationships of the following formulas (1) and (2), A black matrix substrate. Ax > Bx ≥ Cx ····· (1) Ay > By ≥ Cy ····· (2)

2. The light scattering layer is a light scattering layer containing transparent particles, The black matrix substrate according to Claim 1.

3. The light scattering layer is a light scattering layer containing zinc oxide particles, The black matrix substrate according to Claim 1.

4. The light scattering layer is a light scattering layer containing carbon black and a blue pigment, The black matrix substrate according to Claim 1.

5. The light scattering layer is a light scattering layer containing an ultraviolet absorber, The black matrix substrate according to Claim 1.

6. The light reflective matrix is configured to be laminated on the second black matrix in a two-layer structure of a thin film of titanium or titanium nitride and a thin film of an aluminum alloy added with neodymium, The black matrix substrate according to Claim 1.

7. The light reflective matrix is configured to be laminated on the second black matrix in a three-layer structure of a thin film of a first conductive oxide, a thin film of silver or a silver alloy, and a thin film of a second conductive oxide, The black matrix substrate according to Claim 1.

8. A first transparent resin layer is inserted between the light scattering layer and the second black matrix, The black matrix substrate according to Claim 1.

9. A second transparent resin layer is laminated on the light reflective matrix, The black matrix substrate according to Claim 1.

10. The black matrix substrate according to claims 1 to 8, and at least a display functional layer, A display device comprising the same.

11. The display functional layer is a red light-emitting element, a green light-emitting element, and a blue light-emitting element each driven by a thin-film transistor, The display device according to claim 10.

12. The display functional layer is a red light-emitting diode, a blue light-emitting diode, and a green light-emitting diode each driven by a thin-film transistor, The display device according to claim 10.

13. The display functional layer is a liquid crystal layer each driven by a thin-film transistor, and the display device according to claim 10, comprising a plurality of optical modules each including a red light-emitting diode, a blue light-emitting diode, and a green light-emitting diode as a backlight unit.

Images