TW202422512A - Spliced display device, unit panel group, manufacturing method of spliced display device, and maintenance method of spliced display device - Google Patents

Abstract

The present invention relates to a spliced display device, which is formed by arranging a plurality of unit panels having a transparent substrate with an anti-reflection film on the display side, and the transparent substrate with the anti-reflection film has a transparent substrate, a diffusion layer and an anti-reflection film in sequence facing the display side, and two adjacent unit panels meet the specified condition 1.

Description

Spliced display device, unit panel group, manufacturing method of spliced display device, and maintenance method of spliced display device

The present invention relates to a spliced display device, a unit panel group, a manufacturing method of the spliced display device and a maintenance method of the spliced display device.

In recent years, from the perspective of aesthetics, the industry has adopted a method of providing a transparent substrate such as a cover glass on the front surface of an image display device such as a liquid crystal display (LCD). In addition, in order to prevent external light from being reflected into the transparent substrate, a transparent substrate with an anti-reflection film (hereinafter also referred to as a transparent substrate with an anti-reflection film) is known. For example, Patent Document 1 discloses a transparent substrate with an anti-reflection film that has light absorption capability and is insulating.

In order to prevent the reflection of external light, it is also known to set a diffusion layer on a transparent substrate. The diffusion layer suppresses the reflection of external light by diffusing the incident light. As an example of a method of setting a diffusion layer, a method of laminating a film (anti-glare film) having a diffusion layer to the main surface of a transparent substrate or a panel of an image display device can be cited.

In addition, when the transparent substrate has a diffusion layer, when used in an image display device, the screen when turned off may appear white due to the diffused light. Therefore, it is also considered to further provide the above-mentioned anti-reflection film on the diffusion layer. Thereby, the reflection of the incident light can be suppressed, and the white color can be suppressed, so that the reflection can be well suppressed, and the black texture of the screen when turned off can be improved.

In recent years, the demand for display devices to have larger screens has increased. If a single display panel is used to realize a large-screen display device, problems may arise from the perspective of mechanical strength or uneven display caused by increased electrode resistance. In contrast, the industry has studied forming display elements into panels, arranging multiple panels in a tile-like manner (joining) as unit panels, and thereby realizing a large screen.

For example, Patent Document 2 describes a spliced display device, which is characterized in that: it is composed of a plurality of unit panels having non-display areas on the periphery arranged in a tile-like manner, and a display sheet using an organic LED (Light Emitting Diode) as a surface light source is arranged in a manner covering the non-display area between the adjacent unit panels. Prior Art Documents Patent Documents

Patent document 1: Japanese Patent Gazette No. 2018-115105 Patent document 2: Japanese Patent Gazette No. 2007-192977

[The problem the invention is trying to solve]

However, when the unit panels constituting the spliced display device have a transparent substrate with an anti-reflection film or an anti-glare film, there is a situation in which the object color (diffuse reflection color) of the transparent substrate with an anti-reflection film or the anti-glare film of each unit panel appears different depending on the angle at which the spliced display device is observed. In this case, the color deviation between the unit panels becomes obvious, and there is a risk that the quality of the spliced display device will be greatly reduced, for example, the appearance when turned off will become various colors. Therefore, the purpose of the present invention is to provide a spliced display device in which the color deviation is not easy to be obvious, a unit panel group used therefor, a method for manufacturing a spliced display device, and a method for maintaining a spliced display device. [Technical means for solving the problem]

The inventors of the present invention have discovered that, when the unit panels constituting a spliced display device have a transparent substrate with an anti-reflection film, they focus on the color tones (a ^* and b ^* ) of diffusely reflected light when light is incident on the main surface of the display surface side of the unit panel at a specified angle. By making a ^* and b ^* of diffusely reflected light at multiple angles meet specified conditions between adjacent unit panels, a spliced display device in which color deviation is not easily noticeable can be obtained, thereby completing the present invention.

Furthermore, the inventors of the present invention have discovered that, when the unit panels constituting the spliced display device have an anti-glare film, by focusing on the directionality of the anti-glare property in the anti-glare film and making the anti-glare index of the main surface on the display surface side of the unit panel meet specified conditions between adjacent unit panels, a spliced display device in which color deviation is not easily apparent can be obtained, thereby completing the present invention.

That is, the present invention relates to the following 1 to 10. 1. A spliced display device, which is formed by arranging a plurality of unit panels having a transparent substrate with an anti-reflection film on the display side, and the transparent substrate with an anti-reflection film has a transparent substrate, a diffusion layer and an anti-reflection film in sequence facing the display side, and the two adjacent unit panels meet the following condition 1. 2. The spliced display device as described in 1 above, wherein the haze value of the transparent substrate with an anti-reflection film is greater than 30%.

3. A unit panel group, which is used for a spliced display device formed by arranging a plurality of unit panels having a transparent substrate with an anti-reflection film on the display side, and the transparent substrate with an anti-reflection film has a transparent substrate, a diffusion layer and an anti-reflection film in sequence facing the display side, and 2 unit panels selected arbitrarily from the unit panel group meet the following condition 1. 4. The unit panel group as described in 3 above, wherein the haze value of the transparent substrate with an anti-reflection film is 30% or more.

5. A method for manufacturing a spliced display device, which is a method for manufacturing a spliced display device in which a plurality of unit panels having a transparent substrate with an anti-reflection film on the display surface side are arranged, and comprises: for the plurality of the above-mentioned unit panels, confirming a* and b* under a D65 light source of diffuse reflected light at angles of -15°, 15° and 25° relative to the mirror reflected light when the light source is incident on the main surface on the display surface side at an incident angle ^{of 45° ;} and selecting a combination of unit panels that meets the following condition 1, and arranging the unit panels belonging to the above-mentioned combination in a manner that the unit panels are adjacent to each other.

6. A maintenance method for a spliced display device, which is a maintenance method for a spliced display device formed by arranging a plurality of unit panels having a transparent substrate with an anti-reflection film on the display surface side, and includes: selecting a unit panel to be replaced from the unit panels constituting the spliced display device; for at least one adjacent unit panel adjacent to the above-mentioned unit panel to be replaced, confirming a* and b* under a D65 light source of diffuse reflected light at angles of -15°, 15° and 25° relative to mirror reflected light when the light source is incident on the main surface on the display surface side at an incident angle of ^{45° ;} and replacing the above-mentioned unit panel to be replaced in a manner that the replaced unit panel satisfies the following condition 1 relative to the above-mentioned adjacent unit panel.

7. A spliced display device as described in 1 or 2 above, wherein the transparent substrate with an anti-reflection film includes an anti-glare film as the diffusion layer and the transparent substrate, and the two adjacent unit panels meet the following condition 2.

8. A spliced display device, which is formed by arranging a plurality of unit panels with anti-glare films on the display side, and Two adjacent unit panels meet the following condition 2.

9. A method for manufacturing a spliced display device, which is a method for manufacturing a spliced display device formed by arranging a plurality of unit panels having an anti-glare film on the display side, and includes arranging the unit panels in such a way that the adjacent unit panels satisfy the following condition 2.

10. A maintenance method for a spliced display device, which is a maintenance method for a spliced display device formed by arranging a plurality of unit panels with anti-glare films on the display side, and includes: Selecting a unit panel to be replaced from the unit panels constituting the spliced display device; and Replacing the unit panel to be replaced in such a manner that the replaced unit panel satisfies the following condition 2 relative to at least one adjacent unit panel adjacent to the unit panel to be replaced.

In the above 1 to 7, condition 1 is as follows. (Condition 1) When a light source is incident on the main surface of the display surface side of one of the two unit panels at an incident angle of 45°, a ^* and b ^* of diffuse reflected light under a D65 light source at angles of -15°, 15° and 25° relative to the mirror reflected light are set as _ax ^* and _bx ^* at each angle, and a ^* and b ^* measured in the same manner for the other unit panel are set as _ay ^* and _byy ^* at each angle, Δa ^* b ^* at each angle is 3.0 or less. Δa ^* b ^* =(( _ax ^* _-ay ^* ) ² +( _bx ^* -by _* ^{) 2} ) ^1/2

In the above 7 to 10, condition 2 is as follows. (Condition 2) The difference between the angle of the direction in which the L ^* value of one of the two adjacent unit panels is the largest, obtained by the following method, and the angle of the direction in which the L ^* value of the other unit panel is the largest measured in the same manner is 35° or less. (Method) On a surface parallel to the main surface of the spliced display device, one of the directions parallel to the side shared by the two adjacent unit panels is set as the 0° direction. While changing the incident direction from the 0° direction to the 360° direction at intervals of 10°, the light source is incident on the main surface of the unit panel to be measured on the display surface side at an incident angle of 45°. For each incident direction, the L ^* value of diffusely reflected light under a D65 light source at an angle of -15° relative to the incident light is measured, and the angle of the incident direction with the maximum L ^* value is taken as the angle of the direction with the maximum L ^* value of the unit panel to be measured. [Effect of the invention]

According to one aspect of the present invention, a spliced display device with less obvious color deviation, a unit panel group used therefor, a manufacturing method of the spliced display device, and a maintenance method of the spliced display device can be provided. By making the color deviation less obvious, the quality or aesthetics of the spliced display device can be improved.

The present invention is described in detail below, but the present invention is not limited to the following implementation modes, and can be implemented with any changes within the scope of the present invention. In addition, "～" indicating a numerical range is used to include the numerical values recorded before and after it as the lower limit and upper limit. Furthermore, in this specification, the so-called having other layers or films on the main surface of a substrate such as a transparent substrate, or on a layer such as a diffusion layer, or on a film such as an anti-reflection film, is not limited to the other layers or films being arranged in contact with the above-mentioned main surface, layer, or film, as long as the layer or film is arranged in the upper direction thereof. For example, the so-called diffusion layer on the main surface of the transparent substrate may be provided in a manner that the diffusion layer is in contact with the main surface of the transparent substrate, or any other layer or film may be provided between the transparent substrate and the diffusion layer. In this specification, unless otherwise specified, a ^* , b ^* , and L ^* refer to a ^* , b ^* , and L ^* under D65 light source, respectively. In the following figures, components and parts that play the same role are sometimes labeled with the same symbols and explained, and sometimes repeated explanations are omitted or simplified. In addition, the implementation methods recorded in the figures are modeled for the purpose of clearly explaining the present invention, and may not accurately represent the size or reduction ratio of the actual device, etc.

(First embodiment) (Spliced display device) The spliced display device of the first embodiment of the present invention is formed by arranging a plurality of unit panels having a transparent substrate with an anti-reflection film on the display surface side, and the transparent substrate with an anti-reflection film has a transparent substrate, a diffusion layer and an anti-reflection film in sequence facing the display surface, and two adjacent unit panels meet the following condition 1. (Condition 1) When a light source is incident on the main surface of the display surface side of one of the two unit panels at an incident angle of 45°, a ^* and b ^* of diffuse reflected light under a D65 light source at angles of -15°, 15° and 25° relative to the mirror reflected light are set as _ax ^* and _bx ^* at each angle, and a ^* and b ^* measured in the same manner for the other unit panel are set as _ay ^* and _byy ^* at each angle, Δa ^* b ^* at each angle is 3.0 ^or less. Δa ^* b ^* = ((ax _{* -ay} ^* ) ² + ( _bx ^* -by _* ^{) 2} ) ^1/2

FIG. 1 is a three-dimensional diagram schematically showing a splicing display device of the first embodiment. The splicing display device 100 in FIG. 1 is composed of a unit panel 5a and a unit panel 5b, and includes a total of two unit panels. The unit panels 5a and 5b are display panels having transparent substrates 1a and 1b with anti-reflection films at least on their display surfaces. In FIG. 1 , the parts constituting the display panel other than the transparent substrate with anti-reflection films, such as the parts including display elements determined according to the image display method (type of display device), are schematically illustrated as main body parts 7a and 7b constituting the substantial body of the display panel. Furthermore, in this specification, the so-called display surface side refers to the side of the spliced display device or the unit panel that displays the image. In Figures 1 to 7, the direction toward the upper side of the paper is referred to as the display surface side. In addition, in this specification, the display surface side is sometimes referred to as the front surface side, and the opposite side is referred to as the back side. In the spliced display device or the unit panel, when "front view" is mentioned, it means the situation that the observer observes perpendicularly relative to the above-mentioned display surface (front surface), and when "oblique view" is mentioned, it means the situation that the observer observes obliquely relative to the above-mentioned display surface (front surface).

Fig. 2 is a cross-sectional view schematically illustrating an example of the structure of a transparent substrate with an anti-reflection film in each unit panel. The unit panel 5 shown in Fig. 2 has a transparent substrate 1 with an anti-reflection film on the front surface side and a main body 7 on the back side. The transparent substrate 1 with an anti-reflection film has a transparent substrate 10, a diffusion layer 31 and an anti-reflection film 30 in this order toward the front surface side (display side).

In the spliced display device of the first embodiment, two adjacent unit panels satisfy the above-mentioned condition 1. FIG. 3 is a schematic diagram illustrating a method for measuring a ^* and b ^* of diffusely reflected light at various angles under condition 1. In the transparent substrate 1 with an anti-reflection film disposed on the display surface side of the unit panel 5, the transparent substrate 10 has a main surface 11 and another main surface 12, and a diffusion layer 31 and an anti-reflection film 30 are formed on one of the main surfaces 11 serving as the display surface side. Light is incident from a light source 50 at an incident angle of 45° onto the main surface on the display surface side of the unit panel 5, that is, onto the side of one of the main surfaces 11 of the transparent substrate 1 with an anti-reflection film. As a light source for incidence, one that emits light in the entire visible range is used. As the light source, for example, a white light source such as a high color rendering index white LED can be appropriately used. The specular reflection light 61 of the incident light 60 is taken as a reference (0°), and the diffuse reflection lights 71, 72, and 73 are diffuse reflection lights at -15°, 15°, and 25°, respectively. Here, the specular reflection light 61 is set to 0°, the direction in which the angle increases toward the side where the incident light 60 exists is set to the + direction, and the direction in which the angle increases toward the side opposite to the incident light 60 is set to the - direction. For the diffuse reflection light at each of these angles, the reflectivity of the visible light wavelength is measured, and L ^* , a ^* , and b ^* under the D65 light source are calculated. This measurement can be performed using, for example, CM-M6 manufactured by Konica Minolta.

Here, for the main surface of the display surface side of one of the two adjacent unit panels, a ^* and b ^* under the D65 light source of diffuse reflection light at each angle are set as _{ax* and bx* at each angle. That is, for the main surface of the display surface side of one unit panel, ax} ^* _and ^bx _* ^at _-15 ^° , _ax ^* and _bx ^* at 15°, and _ax ^* and _bx ^* at 25° are measured. For the other unit panel, _ay ^* and by ^* at -15°, _ay ^* and by _* at 15°, and _ay ^* and _by ^* at 25° are measured in the _same way ^. Furthermore, when Δa＊b＊ obtained from _ax ^＊ , _bx ^＊ , _ay ^{＊ ,} and by＊ at -15°, _ax ^＊ , _bx ^＊ , _ay ^＊ _, and by＊ at 15°, and _ax ^＊ , _bx ^＊ , _ay ^＊ , and _by ^＊ at 25° are ^{all 3.0 or less, it can be judged that condition 1 is satisfied. Δa＊} _b ^{＊ ＝} (( _ax ^＊ _－ay ^{＊ ) 2＋} ( _bx ^＊ _－by ^{＊ ) 2} ) ^1/2

By making two adjacent unit panels satisfy the above condition 1, it means that the color tone of the diffuse reflected light at the same angle between the adjacent unit panels is relatively close (the color difference is small). In this way, the color deviation of the spliced display device of the first embodiment is suppressed. That is, in condition 1, from the perspective of reducing the color difference of the diffuse reflected light at each angle, Δa ^* b ^* at each angle is less than 3.0, preferably less than 2.5, and more preferably less than 2.0.

Previously, when evaluating the color tone of an object, it is known to use the SCE (Specular Component Exclude) method to evaluate the color tone of reflected light. This is a method of removing the specular reflected light from the reflected light when the light contacts the object and measuring only the diffuse reflected light to evaluate its color tone. If the color tone of an object is evaluated by the SCE method, it is considered that the color tone can be evaluated as close when the object is visually observed. However, the inventors of the present invention have found that when the color tones evaluated by the SCE method are made close to those of two adjacent unit panels, although the color deviation is easily reduced when viewed from the front, the suppression of color deviation when observed from various angles such as oblique directions is sometimes not sufficient. In contrast, according to the present invention, by adjusting the color tones of diffusely reflected light at multiple angles for two adjacent unit panels, color deviation can be suppressed when observing from various angles including oblique directions.

In order to obtain a spliced display device in which two adjacent unit panels meet the above requirements, it is preferred to use a transparent substrate with an anti-reflection film disposed on each unit panel, whose angular dependence of diffuse reflected light (the change in the color tone of diffuse reflected light due to the angle) is adjusted to meet the specified conditions. The specific preferred embodiment of the transparent substrate with an anti-reflection film will be described below.

(Unit panel) A unit panel is a display panel having a transparent substrate with an anti-reflection film at least on its display side. A unit panel is a spliced display device formed by arranging a plurality of sheets. The unit panel may be, for example, a display panel used in various display devices such as a μ-LED display device, a liquid crystal display device (LCD display device), an organic EL display device (OLED display device), and an electronic paper display device. Its specific structure is not particularly limited according to the type of display device. As shown in FIG. 2, a unit panel 5 is, for example, a transparent substrate 1 with an anti-reflection film is arranged on the front surface side of a main body 7 formed in a panel shape by bonding or the like. When the transparent substrate with an anti-reflection film is bonded to the main body to form a unit panel, an adhesive or the like may be appropriately used.

The type of display device is not particularly limited and can be appropriately selected according to the purpose, etc. For example, although it also depends on the purpose, a μ-LED display device can be preferably used. In the case of a μ-LED display device, even if the haze of the transparent substrate with an anti-reflection film as described below is relatively large, it is easy to achieve high definition. In addition, an LCD display device or an OLED display device with a relatively small pixel pitch can also be preferably used. In order to make the display high-definition, when the pixel pitch is relatively small, the following adjustments can be made, such as making the haze of the transparent substrate with an anti-reflection film relatively small.

The size of the main surface of each unit panel is not particularly limited. For example, from the perspective of production cost, it is preferably 0.005 to 3 m ² , and more preferably 0.01 to 1.5 m ² . A plurality of unit panels with different main surface sizes may also be included in one spliced display device.

The shape of the main surface of the unit panel is not particularly limited as long as it can be arranged in a tile shape, and can be appropriately selected from various shapes such as polygons and rounded rectangles according to the purpose. Typically, a unit panel with a rectangular main surface shape can be preferably used. In addition, the surface of the unit panel can also be curved, or the panels can be arranged in a manner that describes a curved surface.

(Transparent substrate with anti-reflection film) The transparent substrate with anti-reflection film has a transparent substrate, a diffusion layer and an anti-reflection film in order toward the display surface. The transparent substrate 1 with anti-reflection film shown in FIG2 is configured to form a diffusion layer 31 on one main surface of the transparent substrate 10, and an anti-reflection film 30 is formed on the diffusion layer 31, and the surface on the anti-reflection film side becomes the display surface side of the unit panel. Furthermore, although FIG2 shows a structure in which the diffusion layer 31 is further formed on the transparent substrate 10, the diffusion layer can also be formed on the surface of the transparent substrate itself by a method of surface treatment of the transparent substrate, etc. as described below.

As a transparent substrate with an anti-reflection film, it is preferred that when a light source is incident on one main surface of the transparent substrate with an incident angle of 45°, a ^* and b ^* of diffuse reflected light at angles of -15°, 15°, 25°, 45°, 75° and 110° relative to the mirror reflected light under a D65 light source are measured, and at least one of the following conditions A to D is satisfied.

(Condition A) a ^* and b ^* under D65 light source of diffuse reflected light at angles of 15°, 25° and 45° satisfy the following equations (A1) to (A3). (A1) -8 ≦ a ^* ≦1 (A2) -2 ≦ b ^* ≦6 (A3) b ^* ≦ -1×a ^* -1

(Condition B) a ^* and b ^* under the D65 light source of diffuse reflected light at angles of -15°, 15°, 25°, 45°, 75° and 110° satisfy the following equations (B1) to (B4). (B1) -6 ≦ a ^* ≦ 2 (B2) -1 ≦ b ^* ≦ 12 (B3) b ^* ≦ -2a ^* +4 (B4) b ^* ≧ -2a ^* -5

(Condition C) a ^* and b ^* under D65 light source of diffuse reflected light at angles of -15°, 15° and 25° satisfy the following equations (C1) and (C2). (C1) -5 ≦ a ^* ≦ -1 (C2) 0 ≦ b ^* ≦ 9

(Condition D) The absolute value of the slope of the approximate straight line calculated from the a ^* b ^* coordinates of diffuse reflected light under D65 light source at angles of -15°, 15°, and 25° is 2 or more.

FIG4 is a diagram schematically illustrating the method of measuring a ^* and b ^* of diffuse reflection light at each angle under conditions A to D. The measurement of a* and b* of diffuse reflection light at each angle under conditions A to D is the same as the method of measuring a ^* and b ^* of diffuse reflection light at each angle under condition 1, except that the measurement is performed on the transparent substrate with an anti-reflection film alone and the diffuse reflection light at 45°, 75° and 110° is measured in addition to -15°, 15° and 25 ^° . In FIG4, diffuse reflection light ⁷¹ , 72, 73, 74, 75 and 76 are diffuse reflection light at -15°, 15°, 25°, 45°, 75° and 110°, respectively. Furthermore, for example, when only confirming whether condition C is met, it is sufficient to at least measure the diffuse reflected light at -15°, 15° and 25° required for confirming the condition, and the same applies to other conditions.

When measuring the transparent substrate with anti-reflection film alone, as shown in FIG4 , the reflection of the other main surface of the transparent substrate with anti-reflection film is removed during the measurement. In the measurement method illustrated in FIG4 , the transparent substrate 1 with anti-reflection film has the reflection of the other main surface removed by attaching a black tape 20 to the other main surface 12. As the black tape for removing the reflection of the other main surface, for example, "Clear Mierre" manufactured by Tomogawa Paper Co., Ltd. can be cited. The diffuse reflectance of the black tape itself is low, and the influence on the diffuse reflectance measurement of the surface of the transparent substrate with anti-reflection film is small.

By providing a transparent substrate with an anti-reflection film with a diffusion layer and an anti-reflection film, the reflection of external light can be suppressed in a unit panel or a spliced display device, and the white color caused by diffuse reflected light can be suppressed, thereby improving the texture with black. On the other hand, the anti-reflection film utilizes optical interference, so the optical path length may change due to the incident angle or the emission angle of the light, and the reflected color (hue) may change in various ways. In particular, when the anti-reflection film is provided on the diffusion layer, the light is easily diffused due to the diffusion layer, so the brightness of the diffused reflected light is easily increased, and the change in hue caused by the angle is easily more obvious. In contrast, in a transparent substrate with an anti-reflection film that satisfies at least one of the above conditions A to D, the angular dependence of the diffused reflected light is adjusted as follows, so the change in hue caused by the angle is suppressed.

That is, when condition A is satisfied, the hue changes within a limited range between substantially achromatic and green depending on the angle. This can suppress the hue from changing in various ways depending on the angle.

When condition B is satisfied, the color tone changes within a limited range from approximately colorless to yellowish green depending on the angle. This can suppress various changes in the color tone due to the angle. In addition, in this configuration, the reflected color maintains yellowish green while the brightness changes slowly, especially from -15° to 45° where the brightness is relatively large, so it can be a configuration that causes particularly little discomfort when visually checking.

When condition C is satisfied, the hue changes within a limited range between approximately colorless or light yellow to yellowish green depending on the angle. This can suppress the hue from changing in various ways depending on the angle.

When condition D is satisfied, even if the hue changes with the angle, the change of a ^* is relatively small, and b ^* mainly changes with the angle. With this change mode, the change of hue caused by the angle can be limited, for example, the hue changes between achromatic and a specified color, and various changes of hue caused by the angle can be suppressed. Furthermore, it becomes a structure that is not easy to cause the following reflection color change, that is, the reflection color changes to green to red that humans easily feel uncomfortable.

Furthermore, the approximate straight line of condition D is specifically calculated by linear approximation based on the a ^* b ^* coordinates of the diffuse reflected light at each angle. That is, in an xy coordinate plane (a ^* b ^* coordinate plane) with a ^* as the x-axis and b ^* as the y-axis, a ^* b ^* of the diffuse reflected light at -15°, 15°, and 25° are plotted respectively, and y(b ^* ) is linearly approximated in the form of a linear equation of x(a ^* ) based on these three points by the least square method to obtain an approximate straight line. For example, the approximate straight line can be obtained by linear approximation using the "Approximate Curve" function of the spreadsheet software "Microsoft Excel" (registered trademark) manufactured by Microsoft Corporation.

By using a transparent substrate with an anti-reflection film that satisfies at least one of the conditions A to D, the color difference between a plurality of unit panels can be easily reduced. The reason is explained. In order to make the angular dependence of diffusely reflected light the same between a plurality of transparent substrates with an anti-reflection film, it is considered to prepare a plurality of transparent substrates with an anti-reflection film having the same film structure of the anti-reflection film. However, even if a plurality of transparent substrates with an anti-reflection film are manufactured under the same conditions, it is difficult to make the angular dependence of diffusely reflected light completely the same due to the subtle unevenness of the film thickness of each dielectric layer constituting the anti-reflection film. At this time, if the angular dependence of diffusely reflected light of the transparent substrate with anti-reflection film is not properly adjusted and the color tone changes with the angle, even if there is a slight difference in the angular dependence, the color difference between diffusely reflected light at the same angle is likely to become large. In contrast, if the transparent substrate with anti-reflection film has a limited change in color tone caused by the angle, such as satisfying at least one of the conditions A to D, then even if the angular dependence of diffusely reflected light between multiple transparent substrates with anti-reflection films is not exactly the same, the color tone of diffusely reflected light at the same angle is likely to become relatively close, and it is easy to obtain a combination of multiple transparent substrates with anti-reflection films that satisfies the above condition 1.

Furthermore, from the viewpoint of limiting the change of hue due to angle, the transparent substrate with anti-reflection film that can easily reduce the color difference is not limited to satisfying any one of the conditions A to D, but can be one that adjusts the change of hue to a limited range in other forms. Among them, when satisfying any one of the conditions A to D, in addition to the limited change of hue, the range of the change of hue is also between colorless and a specified color or pale yellow to yellowish green and other similar colors, which is more preferred because humans tend not to feel uncomfortable.

In order to obtain a transparent substrate with an anti-reflection film that meets various conditions, it is preferred to appropriately adjust the film composition of the anti-reflection film, the visual transmittance (Y) of the transparent substrate with an anti-reflection film, etc. In addition, in the case of a transparent substrate with an anti-reflection film having a high transmittance, it is difficult to achieve adaptation based on the transmittance, so it is preferred to more strictly adjust the film thickness of each layer of the anti-reflection film.

For example, when a transparent substrate with an anti-reflection film satisfying condition A is obtained, it is preferred to make the mirror reflectivity of green light of 500 nm to 550 nm higher than that of blue light of 450 nm to 500 nm or red light of 600 nm to 650 nm at a plurality of light incident angles. In this way, the mirror reflection color can be kept black (colorless) to green at a plurality of light incident angles, and as a result, the diffuse reflection color at a plurality of incident angles can also be kept colorless to green. The angular dependence of the mirror reflection color can be easily predicted by using thin film simulation software. Furthermore, in terms of reducing the deviation in reflected color, it is advantageous to not only satisfy (A1) to (A3) but also to adjust the film thickness of each layer so that the change in b ^* caused by the diffuse reflection angle is reduced.

When a transparent substrate with an anti-reflection film satisfying condition B is obtained, it is preferred that the specular reflectivity for yellow-green light of about 500 to 600 nm is made higher than that for blue light of 450 to 500 nm or red light of 600 to 650 nm at a plurality of light incident angles. In this way, the specular reflection color can be kept black (colorless) to yellow-green at a plurality of light incident angles, and as a result, there is a tendency that the diffuse reflection color at a plurality of incident angles can also be kept black (colorless) to yellow-green.

The transparent substrate with anti-reflection film that meets condition C preferably has a mirror reflectivity of green light of 500 nm to 550 nm that is higher than that of blue light of 450 nm to 500 nm or red light of 600 nm to 650 nm at multiple light incident angles, and preferably the reflectivity of red light is slightly higher than that of blue light. Thus, in terms of the wavelength region from high to low reflectivity, green>red>blue, the mirror reflection color can be maintained from black (colorless) to light yellow-green at multiple light incident angles, and as a result, the diffuse reflection color at multiple incident angles tends to be maintained from colorless to light yellow-green. Furthermore, in terms of reducing the deviation in reflected color, it is advantageous to not only satisfy (C1) and (C2) but also to adjust the film thickness of each layer so that the change in b ^* caused by the diffuse reflection angle is reduced.

As a method for obtaining a transparent substrate with an antireflection film that satisfies condition D, the film thickness can be adjusted in the same manner as condition C, but the reflected color does not necessarily need to be green. For example, when the reflection of green light of 500 nm to 550 nm is made slightly lower than the reflection of blue light of 450 nm to 500 nm or red light of 600 nm to 650 nm, the reflected color tends to be light reddish blue to light reddish orange, which is preferred.

Furthermore, for example, by satisfying the following, it tends to be easy to obtain a transparent substrate with an antireflection film that satisfies one or more of the conditions A to D.

For example, the total film thickness of the anti-reflection film is preferably 200 nm to 250 nm, and more preferably 210 nm to 245 nm. In this way, the angular dependence of the diffuse reflection color, that is, the change in the color tone of the diffuse reflection light caused by the angle, can be suppressed, and there is a tendency to easily meet one or more of the conditions A to D. In addition, the number of layers of the anti-reflection film is preferably 4 to 8 layers, and more preferably 4 to 6 layers. In this way, mass production can be ensured and the angular dependence of the diffuse reflection color can be suppressed, and there is a tendency to easily meet one or more of the conditions A to D. In addition, regarding the film thickness of each layer, the film thickness of the first layer of the high refractive index layer is the most important, preferably 1 to 25 nm, and more preferably 2 to 15 nm. This can suppress the angular dependence of diffuse reflection color, that is, the increase in the change in the color tone of diffuse reflection light caused by the angle, and tends to easily meet one or more of the conditions A to D.

Regarding the transparent substrate with an anti-reflection film, from the perspective of preventing reflection well, the haze value is preferably 30% or more, more preferably 40% or more, and further preferably 50% or more. From the perspective of improving the clarity of the image when used in an image display device, the haze value is preferably 90% or less, for example. In recent years, transparent substrates with anti-reflection films having relatively high haze values as described above are gradually being used well for relatively large display devices. The reason is that, first, when the display device is large, it is easier for illumination or external light to be reflected, so better prevention of reflection is required. Furthermore, secondly, the industry is studying a large display device that uses, for example, a μ-LED display device with a relatively large pixel pitch, which can easily become a high-definition display device even if the haze value becomes relatively high. However, in a transparent substrate with an anti-reflection film having such a relatively high haze value, the components that undergo diffuse reflection become more numerous, so it can be seen that with the increase in haze, the change in the hue of the diffusely reflected light caused by the angle or the color deviation during splicing tends to become particularly obvious. In contrast, according to the present invention, even when the haze value is such a relatively high situation, a spliced display device with well suppressed color deviation can be obtained.

Furthermore, in applications such as LCD display devices, for example, a transparent substrate with an anti-reflection film having a haze value of about 0 to 30% is sometimes appropriately used. In the present invention, the haze value may be, for example, less than 30% or less than 30% depending on the application. The haze value may be adjusted, for example, by the surface shape of the diffusion layer. The haze value is measured according to JIS K 7136:2000 using a fog meter (HZ-V3 manufactured by Suga Test Instruments).

(Brightness L ^* ) Regarding the transparent substrate with an antireflection film, the brightness L ^* of diffuse reflected light at each angle measured by the same method as a ^* and b ^* of diffuse reflected light at each angle in conditions A to D is preferably within the following range.

The L ^* of diffuse reflected light at -15° under D65 light source is preferably 30 to 60, more preferably 40 to 55. By making the L ^* of diffuse reflected light at -15° within this range, the transparent substrate with anti-reflection film has appropriate light diffusion (anti-glare) or low reflectivity, and the reflection of external light can be well suppressed.

The L ^* of diffuse reflected light at 15° under D65 light source is preferably 15 to 35, more preferably 20 to 30. By making the L ^* of diffuse reflected light at 15° within this range, the transparent substrate with anti-reflection film has appropriate light diffusion (anti-glare) or low reflectivity, and the reflection of external light can be well suppressed.

The L ^* of diffuse reflected light at 25° under D65 light source is preferably 5 to 20, more preferably 7 to 15. By making the L ^* of diffuse reflected light at 25° within this range, the transparent substrate with anti-reflection film has appropriate light diffusion (anti-glare) or low reflectivity, and the reflection of external light can be well suppressed.

(Visual transmittance: Y) The transparent substrate with an anti-reflection film preferably has a visual transmittance (Y) of 20 to 90%. If the visual transmittance (Y) is within the above range, the transparent substrate with an anti-reflection film has a moderate light absorption ability, so when used as a cover glass of an image display device, the reflection of light can be suppressed. This improves the contrast of the bright area of the image display device. The above visual transmittance (Y) is more preferably 50 to 90%, and more preferably 60 to 90%. However, for example, when the brightness of the display device is to be maintained at a higher level, it is sometimes appropriate to use an anti-reflection film that does not have a light absorption ability or has a relatively high transmittance and a visual transmittance of 90% or more as a transparent substrate with an anti-reflection film. In this case, the visual transmittance (Y) can be 90 to 96%, preferably 93 to 96%. Furthermore, the visual transmittance (Y) can be measured by the method specified in JIS Z 8701 (1999) as described in the following embodiment.

In order to make the visual transmittance (Y) of the transparent substrate with antireflection film 20-90%, for example, it is preferred to mainly use a mixed oxide of at least one oxide selected from the group A consisting of Mo and W and at least one oxide selected from the group B consisting of Si, Nb, Ti, Zr, Ta, Al, Sn and In as the first dielectric layer of the antireflection film, and adjust the oxidation amount of the film. In addition, in the case of forming an antireflection film with a relatively high transmittance and a visual transmittance of 90% or more as a transparent substrate with antireflection film, for example, at least one oxide selected from Nb, Ti, Zr, Ta, Al, Sn, Mo, W and In can be used as the first dielectric layer.

The visual transmittance (Y) of the transparent substrate with an anti-reflection film of this embodiment can be adjusted by controlling the irradiation time, irradiation output, distance from the substrate, and amount of oxidizing gas of the oxidizing source during the formation of the first dielectric layer serving as a high refractive index layer in the anti-reflection film.

(Transparent substrate) The transparent substrate with two main surfaces in this embodiment (hereinafter referred to as the transparent substrate) preferably has a refractive index of 1.4 or more and 1.7 or less. If the refractive index of the transparent substrate is within the above range, the reflection of the contact surface can be sufficiently suppressed when optically contacting a display device or a touch panel. The refractive index is more preferably 1.45 or more, more preferably 1.47 or more, more preferably 1.65 or less, and more preferably 1.6 or less.

The transparent substrate preferably includes at least one of glass and resin. More preferably, the transparent substrate includes both glass and resin. By making the transparent substrate include glass, the strength, flatness, and durability of the transparent substrate with an anti-reflection film can be improved. In addition, by laminating the laminate formed by the resin substrate-diffusion layer described below to the glass substrate, the diffusion layer can be easily formed. In the transparent substrate with an anti-reflection film on which the diffusion layer is formed by this method, the transparent substrate includes both glass and resin.

When the transparent substrate includes glass, the type of glass is not particularly limited, and glasses with various compositions can be used. Among them, the glass preferably includes sodium, and preferably has a composition that can be strengthened by forming and chemical strengthening treatment. As the glass, specifically, for example, aluminum silicate glass, sodium calcium glass, borosilicate glass, lead glass, alkaline barium glass, aluminum borosilicate glass, etc. Furthermore, in this specification, when the transparent substrate includes glass, the transparent substrate is also referred to as a glass substrate.

The thickness of the glass substrate is not particularly limited. When the glass is subjected to chemical strengthening treatment, in order to effectively perform chemical strengthening, it is preferably 5 mm or less, more preferably 3 mm or less, and further preferably 1.5 mm or less. In addition, the thickness is, for example, 0.2 mm or more, preferably 0.2 mm or more and 5 mm or less.

The glass substrate is preferably a chemically strengthened glass. This increases the strength of the transparent substrate with the anti-reflection film. Furthermore, when the glass substrate is subjected to the following anti-glare treatment, the chemical strengthening is preferably performed after the anti-glare treatment and before the anti-reflection film (multi-layer film) is formed.

When the transparent substrate includes a resin, the type of resin is not particularly limited, and resins having various compositions can be used. Among them, the above-mentioned resin is preferably a thermoplastic resin or a thermosetting resin, for example, polyvinyl chloride resin, polyethylene resin, polypropylene resin, polystyrene resin, polyvinyl acetate resin, polyester resin, polyurethane resin, cellulose resin, acrylic resin, AS (acrylonitrile-styrene) resin, ABS resin, etc. (Acrylonitrile-butadiene-styrene) resin, fluorine resin, thermoplastic elastomer, polyamide resin, polyimide resin, polyacetal resin, polycarbonate resin, modified polyphenylene ether resin, polyethylene terephthalate resin, polybutylene terephthalate resin, polylactic acid resin, cyclic polyolefin resin, polyphenylene sulfide resin, etc. Among them, cellulose resin is preferred, and examples thereof include triacetyl cellulose resin, polycarbonate resin, polyethylene terephthalate resin, etc. These resins may be used alone or in combination of two or more. In terms of excellent visible light transparency or ease of acquisition, the resin is preferably at least one resin selected from polyethylene terephthalate, polycarbonate, acrylic resin, silicone and triacetyl cellulose. In addition, in this specification, when the transparent substrate includes a resin, the transparent substrate is also referred to as a resin substrate.

The shape of the resin substrate is preferably a film. When the resin substrate is a film, that is, a resin film, its thickness is not particularly limited, but is preferably 20 to 300 μm, more preferably 30 to 130 μm.

Regarding the case where the transparent substrate includes both glass and resin, for example, a composite substrate formed by laminating a glass substrate and a resin substrate can be exemplified. More specifically, the transparent substrate can be, for example, a state in which the resin substrate is provided on the glass substrate.

(Diffusion layer) The diffusion layer in this embodiment is provided on one main surface of the transparent substrate. The so-called diffusion layer means a layer having the function of diffusing the mirror-reflected light and reducing glare or reflection. As a diffusion layer, for example, there can be cited: a diffusion layer formed by a diffusion layer composition that imparts the function of diffusing the mirror-reflected light to the hard coating layer (anti-glare property), or a diffusion layer formed on the surface layer of the transparent substrate itself that imparts anti-glare property by surface treatment of the transparent substrate, etc.

The diffusion layer can be provided with an anti-glare property by making one side of the diffusion layer have an uneven shape or by including microparticles as scattering sources in the resin, thereby increasing the haze value by external scattering or internal scattering. The diffusion layer is formed, for example, by the following diffusion layer composition, which is formed by dispersing at least a particulate substance having anti-glare properties in a solution in which a polymer resin serving as a binder is dissolved. The diffusion layer can be formed by, for example, coating the above-mentioned diffusion layer composition on one main surface of a transparent substrate.

Examples of the above-mentioned particulate material having anti-glare properties include inorganic fine particles such as silica, clay, talc, calcium carbonate, calcium sulfate, barium sulfate, aluminum silicate, titanium oxide, synthetic zeolite, aluminum oxide, and bentonite, and organic fine particles such as styrene resins, urethane resins, benzoguanamine resins, silicone resins, acrylic resins, and melamine resins.

In addition, as for the polymer resin used as the binder of the above-mentioned diffusion layer, for example, a polymer resin including polyester resin, acrylic resin, acrylic urethane resin, polyester acrylate resin, polyurethane acrylate resin, epoxy acrylate resin, urethane resin, etc. can be used.

In this aspect, the diffusion layer can be directly formed on a transparent substrate, or a laminate including a resin substrate and a diffusion layer can be prepared in advance and attached to a glass substrate, etc., thereby obtaining a structure in which the diffusion layer is provided on a composite substrate of a glass substrate and a resin substrate. The laminate is preferably a structure in which the diffusion layer is formed on a film-like resin substrate. According to this method, the diffusion layer can be formed more easily and simply.

As a laminate including a resin matrix and a diffusion layer, for example, an anti-glare film can be specifically mentioned, and more specifically, an anti-glare PET (polyethylene terephthalate) film or an anti-glare TAC (Triacetyl Cellulose) film can be mentioned. As an anti-glare PET film, a product name: BHC-III or EHC-30a manufactured by HIGASHIYAMA FILM Co., Ltd., a product name: KONO Co., Ltd., etc. can be mentioned. In addition, as an anti-glare TAC film, an anti-glare TAC film (manufactured by TOPPAN TOMOEGAWA OPTICAL FILMS, product name: VZ50) can be used.

Furthermore, a diffusion layer can be formed on the surface of the transparent substrate itself by performing surface treatment on the transparent substrate. For example, when a glass substrate is used, a method of performing surface treatment on the main surface of the glass and forming the desired concavity and convexity can be used. Specifically, a method of chemically treating the main surface of the glass substrate, such as a method of performing frosting treatment, can be cited. For example, the frosting treatment can be performed by immersing the glass substrate as the treated body in a mixed solution of hydrogen fluoride and ammonium fluoride, and chemically treating the immersion surface. In addition to the method of performing chemical treatment such as frosting, the following treatment methods can also be used, for example: using pressurized air to blow crystalline silica powder, silicon carbide powder, etc. to the surface of the glass substrate, so-called sandblasting treatment; or using water to wet a brush with crystalline silica powder, silicon carbide powder, etc. attached, and using the wetted brush to perform physical treatment such as polishing.

When a transparent substrate with an anti-reflection film having such a diffusion layer has a concavo-convex shape on one side of the diffusion layer, the concavo-convex shape of the diffusion layer causes the surface to have a concavo-convex shape. The Sa (arithmetic mean surface roughness) of the transparent substrate with an anti-reflection film is preferably 0.05 to 0.6 μm, more preferably 0.05 to 0.55 μm. By making Sa within this range, it is easier to suppress the reflection of the reflected image, so it is better. Sa is specified by ISO25178, and can be measured using, for example, a laser microscope VK-X3000 manufactured by Keyence Corporation.

The surface area of the transparent substrate with an anti-reflection film is measured using a laser microscope VK-X3000 manufactured by Keyence Corporation, etc., and the developed area ratio Sdr (hereinafter also referred to as "Sdr") calculated based on the surface area is preferably 0.001 to 0.4, and more preferably 0.0025 to 0.2. By making Sdr within this range, it is easier to suppress the reflection of the reflected image, so it is better. Sdr is specified by ISO25178 and is expressed by the following formula. Developed area ratio Sdr = {(A-B)/B} A: The surface area reflecting the actual unevenness in the measurement area (developed area) B: The area of the plane without unevenness in the measurement area

The Sdq (root mean square slope) of the transparent substrate with an anti-reflection film is preferably 0.03 to 0.50, and more preferably 0.07 to 0.49. When the Sdq is within this range, it is easier to suppress the reflection of the reflected image, so it is more preferable. Sdq is specified by ISO25178 and can be measured using, for example, a laser microscope VK-X3000 manufactured by Keyence Corporation.

The Spc (average value of the principal curvature of the peak point of the surface) of the transparent substrate with an anti-reflection film is preferably 150 to 6000 (1/mm). By making Spc within this range, it is easier to suppress the reflection of the reflected image, so it is more preferable. Spc is specified by ISO25178 and can be measured using, for example, a laser microscope VK-X3000 manufactured by Keyence Corporation.

The above-mentioned Sa, Sdr, Sdq and Spc refer to the values measured on the main surface of the transparent substrate with an anti-reflection film on the side having the diffusion layer and the anti-reflection film.

(Barrier layer) A transparent substrate with an anti-reflection film may have a barrier layer between the transparent substrate and the anti-reflection film. When the transparent substrate includes a resin substrate, for example, when a diffusion layer is formed by laminating a laminate including a resin substrate-diffusion layer to a glass substrate, a barrier layer may be provided between the diffusion layer and the anti-reflection film. By providing a barrier layer between the resin transparent substrate and the anti-reflection film, the influence of moisture or oxygen that penetrates from the resin substrate to the anti-reflection film can be suppressed, and there are advantages such as the optical properties are not easily changed, so it is sometimes preferred. Furthermore, when the transparent substrate includes a glass substrate, by providing a barrier layer between the transparent substrate (glass substrate) and the anti-reflection film, it is possible to suppress the diffusion of alkali metal components and the like into the anti-reflection film, thereby changing the optical properties. Therefore, when the transparent substrate includes a glass substrate, a barrier layer may also be provided between the transparent substrate and the anti-reflection film.

As the barrier layer, for example, a metal nitride film or a metal oxide film can be cited, and specifically, a _SiNx film, a _SiOx film, etc. can be cited. From the viewpoint of more effectively suppressing the change of optical characteristics, a _SiNx film is more preferred. That is, the barrier layer is preferably a layer mainly containing at least one of _SiNx and _SiOx , and more preferably a layer mainly containing _SiNx . The so-called layer mainly containing at least one of _SiNx and _SiOx means a layer in which the component with the largest content on a mass basis is at least one of _SiNx and _SiOx , for example, a layer in which the content of at least one of _SiNx and _SiOx is 70 mass% or more is preferably a layer. As for the thickness of the barrier layer, from the viewpoint of suppressing the penetration of water etc. into the anti-reflection film, it is preferably 2 nm or more, further preferably 4 nm or more, and particularly preferably 8 nm or more. On the other hand, from the viewpoint of suppressing the increase of the reflectivity of the transparent substrate with the anti-reflection film, the thickness is preferably 50 nm or less. The barrier layer can be formed by a known film forming method such as sputtering, vacuum evaporation or coating.

(Anti-reflection film) The anti-reflection film in this embodiment has the function of suppressing the reflection of light, for example, it has a laminated structure formed by laminating at least two dielectric layers with different refractive indices. The anti-reflection film (multilayer film) 30 shown in FIG. 2 is a laminated structure formed by laminating two layers of a first dielectric layer 32 and a second dielectric layer 34 with different refractive indices. The reflection of light is suppressed by laminating the first dielectric layer 32 and the second dielectric layer 34 with different refractive indices. For example, in FIG. 2, the first dielectric layer 32 is a high refractive index layer, and the second dielectric layer 34 is a low refractive index layer.

The antireflection film is a laminated structure formed by laminating at least two dielectric layers having different refractive indices, wherein at least one of the dielectric layers mainly comprises an oxide of Si, and the other at least one of the layers of the laminated structure mainly comprises a mixed oxide of an oxide of at least one selected from a group A consisting of Mo and W and an oxide of at least one selected from a group B consisting of Si, Nb, Ti, Zr, Ta, Al, Sn and In, and the content of the elements of the group B contained in the mixed oxide is preferably 65% by mass or less relative to the total of the elements of the group A contained in the mixed oxide and the elements of the group B contained in the mixed oxide. However, when it is desired to maintain the brightness of the display device at a higher level, for example, when an antireflection film having no light absorption capability or a relatively high visual transmittance of 90% or more is appropriately used as a transparent substrate with an antireflection film, an oxide of at least one selected from Nb, Ti, Zr, Ta, Al, Sn, Mo, W, and In may be used as the layer not containing an oxide of Si. In addition, the layer mainly containing an oxide of Si may contain an oxide of at least one selected from Nb, Ti, Zr, Ta, Al, Sn, W, Mo, and In within a range that does not affect the reflectivity. By appropriately selecting a material as an oxide, an antireflection film having a higher hardness and less change in optical properties can be obtained.

Regarding the antireflection film (multi-layer film) 30 shown in FIG. 2 , when the antireflection film having a visual transmittance of 90% or less as a transparent substrate with an antireflection film is obtained, the first dielectric layer 32 (high refractive index layer) is preferably a mixed oxide mainly comprising an oxide of at least one selected from the A group consisting of Mo and W and an oxide of at least one selected from the B group consisting of Si, Nb, Ti, Zr, Ta, Al, Sn, and In. Furthermore, the mixed oxide is preferably such that the content of the elements of the B group contained in the mixed oxide (hereinafter referred to as the B group content) is 65% by mass or less relative to the total of the elements of the A group contained in the mixed oxide and the elements of the B group contained in the mixed oxide. Here, "mainly" means the component with the largest content (based on mass) in the first dielectric layer 32, for example, it means that the first dielectric layer 32 contains more than 70 mass % of the component.

If the content of the B group in the first dielectric layer (A-B-O) 32, which includes a mixed oxide of at least one oxide selected from the A group consisting of Mo and W and at least one oxide selected from the B group consisting of Si, Nb, Ti, Zr, Ta, Al, Sn and In, is less than 65 mass %, the yellow color of the transmitted light band can be suppressed.

The oxide of at least one selected from group A is preferably Mo or Mo and W, and the oxide of at least one selected from group B is preferably Nb. That is, the first dielectric layer is preferably a mixed oxide of Mo and Nb or a mixed oxide of Mo, W and Nb, and more preferably a mixed oxide of Mo, W and Nb.

As described below, the second dielectric layer may be, for example, an oxygen-deficient silicon oxide layer. Here, previously, the oxygen-deficient silicon oxide layer has a yellowish color in visible light, but if the first dielectric layer is a mixed oxide of Mo and Nb or a mixed oxide of Mo, W and Nb, the yellowing of the silicon oxide layer can be suppressed, which is preferred. In addition, the silicon oxide layer may contain an oxide of at least one selected from Nb, Ti, Zr, Ta, Al, Sn, W, Mo and In in order to improve reliability, and each oxide may have an oxygen deficiency. Furthermore, when the second dielectric layer is formed on a diffusion layer having a relatively high haze as described above, that is, a relatively large surface unevenness, a higher oxidation stability is required during film formation. If the first dielectric layer is a mixed oxide of Mo, W and Nb, it is more preferable because it has excellent oxidation stability during film formation.

The refractive index of the first dielectric layer 32 at a wavelength of 550 nm is preferably 1.8 to 2.5 in view of the transmittance of the transparent substrate.

The extinction coefficient of the first dielectric layer 32 is preferably 0.005 to 3, and more preferably 0.04 to 0.38. If the extinction coefficient is greater than 0.005, the required absorptivity can be achieved with an appropriate number of layers. If the extinction coefficient is less than 3, it is relatively easy to achieve a balance between reflection color tone and transmittance.

The second dielectric layer 34 (low refractive index layer) is preferably mainly composed of an oxide (SiO _x ) of Si. Here, "mainly" means the component with the largest content (mass basis) in the second dielectric layer 34, for example, it means that the component is composed of 70 mass % or more. By making the second dielectric layer 34 (low refractive index layer) mainly contain an oxide (SiO _x ), it becomes a low refractive index, and the reflectivity reduction effect becomes higher, which is preferred. Furthermore, SiO _x may be completely oxidized silicon oxide (SiO ₂ ), but from the viewpoint of improving optical reliability or scratch resistance, it is preferably silicon oxide with oxygen deficiency. In addition, the silicon oxide layer may contain an oxide of at least one selected from Nb, Ti, Zr, Ta, Al, Sn, W, Mo and In to improve reliability, and each oxide may have oxygen deficiency.

The anti-reflection film (multi-layer film) 30 shown in FIG2 is a laminated structure of two layers in total formed by laminating a first dielectric layer 32 and a second dielectric layer 34, but the anti-reflection film (multi-layer film) in this aspect is not limited to this, and may also be a laminated structure formed by laminating three or more dielectric layers having different refractive indices. In this case, it is not necessary for all dielectric layers to have different refractive indices. For example, in the case of a three-layer laminated structure, it may be a three-layer laminated structure of a low refractive index layer, a high refractive index layer, and a low refractive index layer, or a three-layer laminated structure of a high refractive index layer, a low refractive index layer, and a high refractive index layer. In the former case, the two low refractive index layers may have the same refractive index, and in the latter case, the two high refractive index layers may have the same refractive index. In the case of a four-layer stacked structure, it may be a four-layer stacked structure of a low refractive index layer, a high refractive index layer, a low refractive index layer, and a high refractive index layer, or a four-layer stacked structure of a high refractive index layer, a low refractive index layer, a high refractive index layer, and a low refractive index layer. In this case, at least one of the two low refractive index layers and the high refractive index layers may have the same refractive index.

In the case of a laminate structure in which three or more layers having different refractive indices are laminated, a dielectric layer other than the first dielectric layer (ABO) 32 and the second dielectric layer (SiO _x ) 34 may be included. In this case, each layer is selected so as to have a _three -layer structure of a low refractive index layer, a high refractive index layer, and a low refractive index layer, or a three-layer structure of a high refractive index layer, a low refractive index layer, and a high refractive index layer, or a four-layer structure of a low refractive index layer, a high refractive index layer, a low refractive index layer, and a high refractive index layer, or a four-layer structure of a high refractive index layer, a low refractive index layer, a high refractive index layer, and a low refractive index layer, but the second dielectric layer (SiO _x ) 34 is preferably the outermost layer. In order to obtain low reflectivity, if the outermost layer is the second dielectric layer (SiO _x ), it can be made relatively easily. In addition, the reflectivity may be slightly increased, and the second dielectric layer may contain an oxide of at least one selected from Nb, Ti, Zr, Ta, Al, Sn, W, Mo and In to improve reliability. In order to suppress the increase in reflectivity, the content of metals other than Si is preferably 30 at% or less, more preferably 20 at% or less, and further preferably 15 at% or less, excluding oxygen. In addition, when the antifouling film described below is formed on the antireflection film 30, from the viewpoint of bonding related to the durability of the antifouling film, the antifouling film is preferably formed on the second dielectric layer (SiO _x ).

The first dielectric layer (A-B-O) 32 is preferably amorphous. If it is amorphous, it can be manufactured at a relatively low temperature, and when the transparent substrate includes a resin, the resin will not be damaged by heat, and can be well applied.

The anti-reflection film 30 in this embodiment can be formed on the main surface of the transparent substrate using a known film forming method such as sputtering, vacuum evaporation or coating. That is, the dielectric layer constituting the anti-reflection film 30 is formed on the main surface of the diffusion layer 31 using a known film forming method such as sputtering, vacuum evaporation or coating according to the layer stacking order.

Examples of the sputtering method include magnetron sputtering, pulse sputtering, AC (Alternating Current) sputtering, and digital sputtering.

For example, magnetron sputtering is a method of placing a magnet on the back side of a dielectric material serving as a matrix to generate a magnetic field. Gas ion atoms collide with the surface of the dielectric material and are knocked out. This method of sputtering a film with a thickness of several nanometers can form a dielectric continuous film of an oxide or nitride serving as a dielectric material.

For example, digital sputtering is different from the usual magnetron sputtering method. It is a method of forming a thin film of metal oxide by repeatedly performing the following steps in the same chamber: first, an ultra-thin film of metal is formed by sputtering, and then oxidation is performed by irradiating oxygen plasma, oxygen ions, or oxygen free radicals. In this case, since the film-forming molecules are metal when attached to the substrate to form a film, it is speculated that it has ductility compared to the case of attaching the film in the form of metal oxide. Therefore, it is believed that even with the same energy, the film-forming molecules are easy to rearrange, and as a result, a dense and smooth film can be formed.

Furthermore, the above example is an example of a preferred structure of an anti-reflection film, but the structure of the anti-reflection film is not limited to this. For example, when the brightness of the display device is to be maintained at a higher level, it is sometimes appropriate to use an anti-reflection film that does not have light absorption ability, or has a relatively high visual transmittance of more than 90% as a transparent substrate with an anti-reflection film. In such a transparent substrate with an anti-reflection film including a high-transmittance anti-reflection film, as long as a ^* and b ^* of the diffusely reflected light at each angle are within the above range, the effect of suppressing color deviation during splicing can be obtained. As a structure of a high-transmittance anti-reflection film, for example, a structure in which the low refractive index layer is the same as the above-mentioned second dielectric layer 34 and the high refractive index layer has no light absorption ability or is a high-transmittance layer can be exemplified. In this case, the high refractive index layer may be, for example, a layer mainly containing Ti oxide ( _TiOx ), a layer containing Nb oxide ( _NbOx ), a layer containing Ta oxide ( _TaOx ), etc. From the viewpoint of low reflection, a layer mainly containing Ti oxide ( _TiOx ) is preferred. In this case, each layer forming the antireflection film may be formed by a known film forming method such as sputtering, vacuum evaporation or coating. In the case of a high-transmittance antireflection film, the visual transmittance (Y) of the transparent substrate with the antireflection film may be, for example, 90 to 96%, preferably 93 to 96%.

(Antifouling film) From the perspective of protecting the outermost surface of the antireflection film, the transparent substrate with an antireflection film of this embodiment may further have an antifouling film (also called "anti-fingerprint (AFP) film") on the antireflection film. The antifouling film may be composed of, for example, a fluorinated organic silicide. As the fluorinated organic silicide, any fluorinated organic silicide can be used without particular limitation as long as it can impart antifouling properties, water repellency, and oil repellency. For example, a fluorinated organic silicide having one or more groups selected from the group consisting of a polyfluoropolyether group, a polyfluoroalkylene group, and a polyfluoroalkylene group may be cited. Furthermore, the so-called polyfluoropolyether group refers to a divalent group having a structure in which a polyfluoroalkylene group and an etheric oxygen atom are alternately bonded.

In addition, as commercially available fluorinated organic silicides having one or more groups selected from the group consisting of a polyfluoropolyether group, a polyfluoroalkylene group and a polyfluoroalkyl group, KP-801 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.), KY178 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.), KY-130 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.), KY-185 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.), OPTOOL (registered trademark) DSX and OPTOOL AES (both trade names, manufactured by Daikin Industries, Ltd.), etc., which can be used well.

In the case where the transparent substrate with an anti-reflection film of this aspect has an anti-fouling film, the anti-fouling film is provided on the anti-reflection film. In the case where the anti-reflection film is provided on both sides of the two main surfaces of the transparent substrate, the anti-fouling film may be formed on both anti-reflection films, or the anti-fouling film may be laminated on only one side of the main surface. The reason for this is that the anti-fouling film only needs to be provided at a location that may be touched by a hand, etc., and can be selected according to its use, etc.

(Manufacturing method of transparent substrate with anti-reflection film) The manufacturing method of transparent substrate with anti-reflection film is not particularly limited. For example, it can be manufactured by the following method, which includes sequentially forming a diffusion layer and an anti-reflection film on a transparent substrate. In addition, it can also include forming a barrier layer, an anti-fouling film, etc. as needed.

(Composition of splicing display device) The number of unit panels constituting the splicing display device only needs to be at least 2, and the number of panels is not particularly limited. Although it also depends on the size of the unit panel or the size of the required splicing display device, for example, from the perspective of large screen, the number of unit panels is preferably 2 to 1000, and more preferably 4 to 500.

The size of the splicing display device, that is, the area of the image display surface of the splicing display device, is not particularly limited depending on the purpose, etc. For example, from the perspective of large screen, it is preferably 1.5 to 150 m ² , and more preferably 2 to 100 m ² .

The spliced display device is the spliced display device of the first embodiment, and may also be the spliced display device of the second embodiment described below. In this case, in the spliced display device of the first embodiment, the transparent substrate with an anti-reflection film includes an anti-glare film as a diffusion layer and a transparent substrate, and two adjacent unit panels meet the following condition 2.

Furthermore, the transparent substrate with anti-reflection film includes the anti-glare film as a diffusion layer and the transparent substrate, which means that the transparent substrate with anti-reflection film includes the anti-glare film, the diffusion layer of the anti-glare film constitutes the diffusion layer of the transparent substrate with anti-reflection film, and the resin substrate of the anti-glare film constitutes a part or all of the transparent substrate of the transparent substrate with anti-reflection film. The anti-glare film and condition 2 in the second embodiment will be described in detail below.

(Manufacturing method of spliced display device) The manufacturing method of the spliced display device of the first embodiment of the present invention is a manufacturing method of a spliced display device formed by arranging a plurality of unit panels having a transparent substrate with an anti-reflection film on the display surface side, and includes: for the plurality of the above-mentioned unit panels, confirming a* and b ^* under a D65 light source of diffuse reflected light at angles of -15°, 15° and 25° relative to mirror reflected light when the light source is incident on the main surface on the display surface side at an incident angle of 45° (step A11); and selecting a combination of unit panels that meet the above-mentioned condition 1, and arranging the unit panels belonging to the above-mentioned combination in a manner that the unit panels ^are adjacent to each other (step A12).

In a spliced display device, the unit panels that meet condition 1 are arranged adjacent to each other, so that the color difference of diffusely reflected light at multiple angles between the unit panels becomes relatively small, and the color deviation is suppressed.

In step A11, for the plurality of unit panels, a* and b* of diffuse reflection light at angles of -15°, 15°, and 25° relative to the mirror reflection light are confirmed under a D65 light source when the light source is incident on the main surface on the display surface side at an incident angle of 45°. The method for measuring a ^* and b ^* of diffuse reflection light at each angle is the same as the method for measuring a ^* and b ^* of diffuse reflection light at each angle under a D65 light source in the above condition 1. As a method for confirming a ^* and b ^* of diffuse reflection light at ^{each angle} , a method of confirming a measured value that has been measured and recorded in advance can be used, and a method of confirming each time a measurement is performed can also be used. The color tone of an object may change with the passage of time. Therefore, if the color tone is suspected to have changed due to a long time elapsed from the measurement, it is better to re-measure and confirm a ^* and b ^* of diffuse reflected light at each angle.

The plurality of unit panels to be measured are not particularly limited, but preferably, a plurality of transparent substrates with anti-reflection films satisfying at least one of the above conditions A to D are manufactured under the same conditions, and the plurality of unit panels having the plurality of transparent substrates with anti-reflection films disposed on the display side are used as the measurement objects. In this way, it is easy to select a combination of unit panels satisfying condition 1 from the plurality of unit panels.

In step A12, a combination of unit panels that meet condition 1 is selected, and the unit panels belonging to the combination are arranged in such a way that they are adjacent to each other. The selection can be performed based on the confirmation result of step A11.

If the number of unit panels constituting the spliced display device is 3 or more, it is more preferable that the unit panels in the obtained spliced display device are arranged so that the combination of two adjacent unit panels all become a combination of unit panels that meets condition 1. The specific steps of selecting the combination and arranging it are not particularly limited. As long as the unit panel group is selected in such a way that two unit panels selected arbitrarily from a plurality of unit panels meet condition 1, no matter how the unit panels belonging to the unit panel group are arranged, the two adjacent unit panels all meet condition 1, so it can be easily arranged, which is preferred.

There is no particular limitation on the specific method of arranging a plurality of unit panels to form a spliced display device, and a method known in spliced display devices can be adopted. For example, there can be cited: a method of directly connecting the unit panels to each other by providing a member for connecting to an adjacent unit panel on each unit panel as a connecting mechanism; a method of indirectly connecting the unit panels to each other by providing an auxiliary member on the back side of the spliced display device, arranging a plurality of unit panels on the auxiliary member, etc. Furthermore, the unit panels do not have to be physically connected to each other, and as long as a plurality of unit panels are arranged in a tile-like manner, they can be regarded as a spliced display device.

(Unit panel group) The unit panel group of the first embodiment of the present invention is used for a spliced display device formed by arranging a plurality of unit panels having a transparent substrate with an anti-reflection film on the display side, and the transparent substrate with an anti-reflection film has a transparent substrate, a diffusion layer and an anti-reflection film in sequence facing the display side, and two unit panels selected arbitrarily from the unit panel group meet the above condition 1.

According to the unit panel group of the first embodiment of the present invention, when a plurality of unit panels are arranged to form a spliced display device, no matter how the unit panels belonging to the unit panel group are arranged, two adjacent unit panels meet condition 1. In this way, the spliced display device of the first embodiment of the present invention can be easily obtained.

Furthermore, the preferred embodiment of each unit panel constituting the unit panel group is the same as the unit panel used in the first embodiment. For example, the haze value of the transparent substrate with an anti-reflection film provided in the unit panels in the unit panel group is preferably 30% or more.

(Maintenance method of spliced display device) The maintenance method of the spliced display device of the first embodiment of the present invention is a maintenance method of a spliced display device formed by arranging a plurality of unit panels having a transparent substrate with an anti-reflection film on the display surface side, and comprises: selecting a unit panel to be replaced from the unit panels constituting the spliced display device (step B11); for at least one adjacent unit panel adjacent to the above-mentioned unit panel to be replaced, confirming a ^* and b ^* under a D65 light source of diffuse reflected light at angles of -15°, 15° and 25° relative to the mirror reflected light when the light source is incident on the main surface on the display surface side at an incident angle of 45° (Step B12); and replacing the above-mentioned replacement unit panel in such a manner that the replaced unit panel satisfies the following condition 1 relative to the above-mentioned adjacent unit panel (Step B13).

In step B11, a unit panel to be replaced is selected from the unit panels constituting the spliced display device. For example, a unit panel that has failed or a unit panel that has been damaged can be selected as a replacement object. In addition, a unit panel that operates normally can also be selected as a replacement object. For example, a specified selection standard can be set to prevent failures, and unit panels belonging to the standard can be selected as replacement objects. The unit panel to be replaced can be one or more.

In step B12, for at least one adjacent unit panel adjacent to the unit panel to be replaced, a* and b* under a D65 light source are confirmed for diffuse reflection light at angles of -15°, 15°, and 25° relative to the mirror reflection light when the light source is incident on the main surface of the display surface side at an incident angle of 45°. Step B12 is the same as the above-mentioned step A11 except that the object of confirmation is a ^* and ^{b *} of diffuse reflection light at each angle of the adjacent unit panel. Such confirmation methods may be methods of confirming information ⁽ measured values, etc.) that has been measured and recorded in advance, or methods of confirming each time a measurement is performed.

In step B13, the replacement unit panel is replaced in such a manner that the replaced unit panel satisfies the following condition 1 relative to the adjacent unit panel. The replacement here includes not only replacing the entire unit panel with another unit panel, but also replacing a part of the unit panel, such as replacing only the transparent substrate with an anti-reflection film in the unit panel. It is preferred to select an appropriate unit panel or a transparent substrate with an anti-reflection film based on the confirmation result in step B12 and replace it.

According to the maintenance method of the spliced display device of the first embodiment of the present invention, when a part of the unit panel in the spliced display device is replaced, the color deviation of the spliced display device after the replacement can be suppressed.

Furthermore, when there are a plurality of adjacent unit panels relative to one unit panel to be replaced, if step B12 and step B13 are performed on at least one of the adjacent unit panels, the color difference between the adjacent unit panel and the replaced unit panel can be suppressed. If step B12 and step B13 are performed on all adjacent unit panels, the color difference between all adjacent unit panels and the replaced unit panel can be suppressed, which is more preferable.

(Second embodiment) (Spliced display device) The spliced display device of the second embodiment of the present invention is formed by arranging a plurality of unit panels having an anti-glare film on the display surface side, and two adjacent unit panels satisfy the following condition 2. (Condition 2) The difference between the angle in the direction in which the L ^* value of one of the two adjacent unit panels is the maximum, obtained by the following method, and the angle in the direction in which the L ^* value of the other unit panel is the maximum, measured in the same manner, is 35° or less. (Method) On a surface parallel to the main surface of the spliced display device, one of the directions parallel to the side shared by the two adjacent unit panels is set as the 0° direction. While changing the incident direction from 0° to 360° at 10° intervals, the light source is incident on the main surface of the display surface side of the unit panel to be measured at an incident angle of 45°. For each incident direction, the L ^* value of diffusely reflected light at an angle of -15° relative to the incident light is measured under a D65 light source, and the angle of the incident direction with the maximum L ^* value is taken as the angle of the direction with the maximum L ^* value for the unit panel to be measured.

FIG. 5 is a three-dimensional diagram schematically illustrating a spliced display device of the second embodiment. The spliced display device 200 in FIG. 5 is arranged with a unit panel 205a and a unit panel 205b, including a total of two unit panels. The unit panels 205a and 205b are display panels having anti-glare films 201a and 201b at least on their display surfaces. In FIG. 5, the portion constituting the display panel other than the anti-glare film, for example, the portion including the display element determined according to its image display method (type of display device), is schematically illustrated as the main body 207a and 207b constituting the substantial body of the display panel.

Fig. 6 is a cross-sectional view schematically illustrating an example of the structure of the anti-glare film in each unit panel. The unit panel 205 shown in Fig. 6 has an anti-glare film 201 on the front surface side and a main body 207 on the back surface side. The anti-glare film 201 has a resin base 210 and a diffusion layer 231 formed on the resin base 210.

In the spliced display device of the second implementation mode, two adjacent unit panels meet the above-mentioned condition 2.

Here, the angle of the direction in which the L ^* value of condition 2 is the maximum is measured by the above method, more specifically, as described below. FIG. 7 is a diagram illustrating a method for measuring the angle of the direction in which the L ^* value is the maximum for two adjacent unit panels 205a and 205b in the spliced display device 200. More specifically, FIG. 7 is a diagram schematically showing the situation of measuring the L ^* value of diffusely reflected light at -15° when the incident direction is 0° for the unit panel 205b. In the measurement, first, on a surface parallel to the main surface of the spliced display device, one of the directions parallel to the side shared by the two adjacent unit panels is set as the 0° direction. That is, in FIG7 , the direction toward the front direction of FIG7 that is parallel to the side S shared by the unit panel 205a and the unit panel 205b when viewed from the front of the spliced display device is set as the 0° direction D1. There is no restriction on which direction of the directions parallel to the sides shared by the two adjacent unit panels is set as the 0° direction. When the two adjacent unit panels do not share a straight edge, any direction on the main surface of the spliced display device is set as the 0° direction. In addition, the angle that increases clockwise when viewed from the front of the spliced display device is defined as the 0° to 360° directions. Among them, the 0° direction and the 360° direction are the same direction. While changing the incident direction from 0° to 360° at intervals of 10°, the light source is incident on the main surface of the display surface side of the unit panel to be measured at an incident angle of 45°. For example, as shown in FIG7 , when the trajectory of the incident light 80 and the diffusely reflected light 81 is projected onto a surface parallel to the main surface of the spliced display device, when the forward direction of the light in the projection trajectory P is 0°, it can be defined as setting the incident direction to 0° to allow the light source to be incident. In addition, for each incident direction, the L ^* value of the diffusely reflected light under the D65 light source at an angle of -15° relative to the mirror reflected light of the incident light is measured. That is, the L ^{* value is measured in a total of 36 directions for one unit panel, as the L* value when the incident direction is set to the 0° direction, the L* value when} the incident direction is set to the 10° direction, and the L ^* value when the incident direction is set to the 360° direction. And, the angle of the incident direction in which the L ^* value is the largest among the 36 directions is taken as the angle in which the L ^* value of the unit panel to be measured is the largest. Here, the diffusely reflected light at an angle of -15° relative to the mirror-reflected light of the incident light is the same as the diffusely reflected light at -15° in the condition 1 in the above-mentioned first embodiment. The measurement of condition 2 can be performed, for example, using CM-M6 manufactured by Konica Minolta. The light source or measurement conditions used in the measurement can be the same as those of the measurement of condition 1.

The above measurement is performed on two adjacent unit panels, and by comparing the angles in the directions where the L ^* value is the largest, it is determined whether condition 2 is met. The difference between the angles in the directions where the L ^* value is the largest is used to evaluate the substantial closeness of the angles in the two directions. That is, the difference is greater than 0° and less than 180°. For example, for two unit panels, if the angles in the directions where the L ^* value is the largest are 10° and 350°, the difference is 20°.

The magnitude of the L ^* value mentioned above varies depending on the direction on the measured surface, which means that the degree of light diffusivity varies depending on the direction on the measured surface, that is, depending on the direction from which the measured surface is observed. A larger L ^* value at -15° means that the diffuse reflectivity of the anti-glare film is higher, which means that the light diffusivity is higher. In addition, in the anti-glare film, generally speaking, the diffuse reflectivity in the direction parallel to the traveling direction (MD) during manufacturing is greater than the diffuse reflectivity in the transverse direction (TD), and there is a tendency that the diffuse reflectivity in one of the directions on the anti-glare film surface that is parallel to the MD is almost the largest, and the diffuse reflectivity in one of the directions parallel to the TD is almost the smallest. Therefore, the so-called two adjacent unit panels satisfying the above-mentioned condition 2 means that the directions of the anti-glare films respectively possessed by the two unit panels during manufacturing are also consistent with each other on the main surface of the spliced display device, or are configured with a relatively small slope. In other words, it means that the directions of the anti-glare films of the adjacent unit panels on the spliced display device are relatively consistent. Thereby, it is believed that the unevenness of the change in the light diffusion properties of the adjacent unit panels when the spliced display device is observed from various directions can be suppressed, so that the color deviation between the unit panels becomes less obvious. Furthermore, as described above with respect to the SCE method, the color tone of a known object can be measured and evaluated by diffusely reflected light. Therefore, in the second embodiment, it is believed that suppressing the unevenness of L ^* of diffusely reflected light between unit panels can help suppress color deviation.

From the viewpoint of obtaining the above effect more effectively, in condition 2, the difference between the angles in the directions where the L ^* value is maximum is 35° or less, preferably 30° or less, and more preferably 25° or less. The difference between the angles in the directions where the L ^* value is maximum may be 0°.

The method for obtaining a spliced display device that meets condition 2 is not particularly limited, and for example, the following method can be cited: the unit panel is obtained by arranging (bonding) the anti-glare film in a manner that any direction on the anti-glare film (for example, one of the directions parallel to the MD) is parallel to any direction of the main surface of the unit panel (for example, the long side direction), preparing a plurality of the unit panels, and arranging them. That is, it is preferable to prepare the unit panels in a manner that the directions of the anti-glare films respectively possessed by the adjacent unit panels during manufacturing are also consistent with each other on the main surface of the spliced display device, or the slope becomes relatively small, and arrange them. Furthermore, here, the so-called parallel means that the inclination angle relative to the reference line is within 30°, for example.

The difference between the maximum values of the L ^* values of two adjacent unit panels measured at 10° intervals by the above method is preferably 3 or less, more preferably 2 or less, and further preferably 1 or less. When the difference between the maximum values of two adjacent unit panels is relatively small, it is considered that the anti-glare properties of the two adjacent unit panels are of the same magnitude. Thereby, not only the unevenness of the anti-glare properties between the unit panels caused by the difference in diffuse reflection (directivity) determined by the direction on the anti-glare film is suppressed, but also the unevenness caused by the magnitude of the anti-glare properties between the unit panels is suppressed, so that the color deviation can be better suppressed. For example, in a plurality of transparent substrates with anti-glare films and unit panels having the same obtained from anti-glare films manufactured under the same manufacturing conditions, generally speaking, the difference between the maximum values is within the above range.

(Unit panel) The unit panel is a display panel having an anti-glare film at least on its display side. The unit panel in the second embodiment is the same as the unit panel in the first embodiment except that it has an anti-glare film on its display side instead of the transparent substrate with an anti-reflection film. Furthermore, the anti-glare film may also be a transparent substrate with an anti-reflection film having an anti-reflection film on the anti-glare film, which will be described in detail below. In addition, a transparent substrate with an anti-glare film having an anti-glare film attached to the transparent substrate may be arranged on the display side of the unit panel.

(Anti-glare film) The anti-glare film has a resin base and a diffusion layer formed on the resin base. The diffusion layer is formed by forming a layer with an uneven surface or coating a resin mixed with fine particles, thereby increasing the haze and imparting anti-glare properties. As mentioned above, in the anti-glare film, generally speaking, the diffuse reflectance in the traveling direction (MD) during manufacturing is greater than the diffuse reflectance in the transverse direction (TD), so there is a tendency that the L ^* value in one of the directions parallel to the MD on the anti-glare film surface is almost the largest, and the L ^* value in one of the directions parallel to the TD is almost the smallest. It is considered that the difference in L ^* value is caused by the difference in tension between MD and TD when the anti-glare liquid is applied to the resin substrate of the anti-glare film by a roll-to-roll method. Therefore, as the anti-glare film used in the second embodiment, the anti-glare liquid can be wet-applied to the resin substrate of the anti-glare film by a roll-to-roll method. However, if the L ^* value at -15° has the same directivity, the aspect of the anti-glare film is not limited to the above content.

The material of the resin matrix of the anti-glare film is not particularly limited, and for example, a thermoplastic resin or a thermosetting resin can be used. Examples of the thermoplastic resin or the thermosetting resin include polyvinyl chloride resin, polyethylene resin, polypropylene resin, polystyrene resin, polyvinyl acetate resin, polyester resin, polyurethane resin, cellulose resin, acrylic resin, AS (acrylonitrile-styrene) resin, ABS (acrylonitrile -butadiene-styrene) resin, fluorine resin, thermoplastic elastomer, polyamide resin, polyimide resin, polyacetal resin, polycarbonate resin, modified polyphenylene ether resin, polyethylene terephthalate resin, polybutylene terephthalate resin, polylactic acid resin, cyclic polyolefin resin, polyphenylene sulfide resin, etc. Among them, cellulose resin is preferred, and triacetyl cellulose resin, polycarbonate resin, and polyethylene terephthalate resin are more preferred.

The thickness of the resin substrate is not particularly limited, but is preferably 10 μm or more, more preferably 20 μm or more, and is preferably 100 μm or less, more preferably 80 μm or less, from the perspective of productivity.

The diffusion layer can be obtained, for example, by dispersing a particulate substance having at least anti-glare properties in a solution containing a polymer resin as a binder, applying the resulting product (diffusion layer composition) to a resin base, and drying the solution to obtain the diffusion layer.

Examples of the particulate material having anti-glare properties include inorganic particles such as silica, clay, talc, calcium carbonate, calcium sulfate, barium sulfate, aluminum silicate, titanium oxide, synthetic zeolite, alumina, and bentonite, and organic particles such as styrene resins, urethane resins, benzoguanamine resins, silicone resins, and acrylic resins.

In addition, as for the polymer resin used as the adhesive, polyester resin, acrylic resin, acrylic urethane resin, polyester acrylate resin, polyurethane acrylate resin, epoxy acrylate resin, urethane resin, etc. can be used. From the viewpoint of film hardness, the polymer resin used as the adhesive is preferably an acrylic resin.

As the anti-glare film, a commercial product may be used. Examples of commercially available anti-glare films include anti-glare PET films and anti-glare TAC films. Examples of anti-glare PET films include BHC-III or EHC-30a manufactured by HIGASHIYAMA FILM Co., Ltd. and products manufactured by Horizon Co., Ltd. In addition, as the anti-glare TAC film, an anti-glare TAC film (manufactured by TOPPAN TOMOEGAWA OPTICAL FILMS, product name VZ50) may be used.

When the anti-glare film has a concavo-convex shape on one side of the diffusion layer, the surface has a concavo-convex shape due to the concavo-convex shape of the diffusion layer. For example, at least one selected from Sa, Sdr, Sdq and Spc of the anti-glare film in the second embodiment may be the same as the preferred Sa, Sdr, Sdq and Spc of the transparent substrate with an anti-reflection film in the first embodiment. In addition, the haze of the anti-glare film in the second embodiment may be the same as the preferred haze of the transparent substrate with an anti-reflection film in the first embodiment.

The shape of the anti-glare film is usually the same as the shape of the main surface of the unit panel or transparent substrate on which the anti-glare film is to be attached. However, when a portion of the main surface to which the anti-glare film is to be attached is not flat, or when the anti-glare property is not to be imparted to a portion having a specific function such as a camera, the shape of the anti-glare film may be processed so that the anti-glare film is not attached to a specific area of the main surface. In addition, for the same reason, a portion of the anti-glare film may have an area without a diffusion layer.

(Adhesive) In order to adhere the anti-glare film to the unit panel or transparent substrate, it is preferred to use an adhesive as needed.

As adhesives, acrylic adhesives, silicone adhesives, urethane adhesives, etc. can be cited. From the viewpoint of durability, the adhesive is preferably an acrylic adhesive. The adhesive can be applied to the surface of the anti-glare film that does not have a diffusion layer, or can be applied to the surface of the transparent substrate to which the anti-glare film is to be attached. From the viewpoint of durability, it is preferred to apply the adhesive to the anti-glare film. In addition, an adhesive that has been pre-formed into a sheet or the like can also be used. In addition, when the resin substrate of the anti-glare film has self-adhesive properties, the anti-glare film can be attached to the transparent substrate without using an adhesive. Furthermore, a commercially available anti-glare film that has an adhesive pre-applied thereto may also be used.

(Transparent substrate) The anti-glare film includes a resin substrate. The anti-glare film can be bonded to another transparent substrate different from the resin substrate constituting the anti-glare film as needed to produce a transparent substrate with an anti-glare film, which is arranged on the display side of the unit panel. When the transparent substrate with an anti-glare film is arranged on the display side of the unit panel, the preferred embodiment of the transparent substrate in the transparent substrate with an anti-glare film is the same as the preferred embodiment of the transparent substrate in the first embodiment.

(Barrier layer) When the anti-glare film further has an anti-reflection film, the anti-glare film preferably has a barrier layer between the diffusion layer and the anti-reflection film. The preferred embodiment of the barrier layer in the second embodiment is the same as the barrier layer in the first embodiment.

(Anti-reflection film) The anti-glare film may have an anti-reflection film. In this case, the anti-glare film having an anti-reflection film may be regarded as a transparent substrate with an anti-reflection film having a diffusion layer and an anti-reflection film on a transparent substrate (resin substrate in the anti-glare film). In the second embodiment, the anti-glare film may be arranged on the display surface side of the unit panel by arranging such a transparent substrate with an anti-reflection film on the display surface side of the unit panel. The anti-reflection film is preferably provided on the diffusion layer, that is, on the side opposite to the transparent substrate when viewed from the diffusion layer. Furthermore, as described above, other layers such as a barrier layer may be provided between the diffusion layer and the anti-reflection film, and the diffusion layer and the anti-reflection film may not be in contact with each other. The specific structure of the anti-reflection film is not particularly limited as long as it can suppress the reflection of light. For example, it can be the same anti-reflection film as the anti-reflection film illustrated in the first embodiment.

(Antifouling film) From the perspective of protecting the outermost surface, the transparent substrate with an antiglare film may have an antifouling film. The antifouling film is preferably disposed on the outermost surface of the transparent substrate with an antiglare film on the side opposite to the transparent substrate when viewed from the self-diffusion layer. The specific material or preferred embodiment of the antifouling film in the second embodiment is the same as that of the antifouling film in the first embodiment.

(Construction of splicing display device) The number of unit panels constituting the splicing display device in the second embodiment or the size of the splicing display device is not particularly limited, and the preferred embodiment is the same as the splicing display device in the first embodiment.

The spliced display device is the spliced display device of the second embodiment, and may also be the spliced display device of the first embodiment. In this case, the spliced display device of the second embodiment has a transparent substrate with an anti-reflection film, and two adjacent unit panels meet the above condition 1.

(Manufacturing method of spliced display device) The manufacturing method of the spliced display device of the second embodiment of the present invention is a manufacturing method of a spliced display device in which a plurality of unit panels having an anti-glare film on the display side are arranged, and includes arranging the unit panels in such a manner that the adjacent unit panels satisfy the above condition 2 (step A21).

In a spliced display device, adjacent unit panels are arranged in a manner that satisfies condition 2, thereby suppressing unevenness in the degree of anti-glare between the unit panels and suppressing color deviation.

In step A21, as a method of arranging the unit panels in such a manner that the adjacent unit panels satisfy condition 2, for example, the following method can be cited: the unit panels are obtained by arranging (bonding) the anti-glare film in such a manner that any direction on the anti-glare film (for example, one of the directions parallel to the MD) is parallel to any direction of the main surface of the unit panel (for example, the long side direction), preparing a plurality of the unit panels, and arranging them. That is, it is preferable to prepare the unit panels in such a manner that the directions of the anti-glare films respectively possessed by the adjacent unit panels during manufacturing are also consistent with each other on the main surface of the spliced display device, or the slope becomes relatively small, and arrange them. Alternatively, the L ^* value at -15° in a plurality of directions on the unit panel or the direction in which the L ^* value is the maximum value may be confirmed in advance, and the unit panel may be arranged based on the confirmation result so that adjacent unit panels satisfy condition 2. Such confirmation methods may be methods of confirming information (measured values, etc.) that has been measured and recorded in advance, or methods of confirming each time a measurement is performed.

If the number of unit panels constituting the spliced display device is 3 or more, it is better that the unit panels in the obtained spliced display device are arranged so that the combination of 2 adjacent unit panels all become a combination of unit panels that meets condition 2.

The specific method of forming a spliced display device by arranging a plurality of unit panels is not particularly limited, and a known method in spliced display devices can be adopted. For example, the spliced display device can be formed by the method exemplified in the manufacturing method of the spliced display device of the first embodiment.

(Maintenance method of spliced display device) The maintenance method of the spliced display device of the second embodiment of the present invention is a maintenance method of a spliced display device formed by arranging a plurality of unit panels with anti-glare films on the display side, and includes: selecting a unit panel to be replaced from the unit panels constituting the spliced display device (step B21); and replacing the above-mentioned unit panel to be replaced in a manner that the replaced unit panel satisfies the above-mentioned condition 2 relative to at least one adjacent unit panel adjacent to the above-mentioned unit panel to be replaced (step B22).

In step B21, a unit panel to be replaced is selected from the unit panels constituting the spliced display device. Step B21 is the same as step B11 in the spliced display device maintenance method of the first embodiment.

In step B22, the unit panel to be replaced is replaced in such a manner that the replaced unit panel satisfies the above-mentioned condition 2 relative to at least one adjacent unit panel adjacent to the unit panel to be replaced. The replacement here includes not only replacing the entire unit panel with another unit panel, but also replacing a part of the unit panel, such as replacing only the anti-glare film in the unit panel. As a specific method for replacing the unit panel to be replaced in such a manner as to satisfy the above-mentioned condition 2, for example: for the unit panel that can be used for replacement and the adjacent unit panel, the lamination direction of the anti-glare film of each unit panel is confirmed, and the unit panel is replaced based on the confirmation result. Alternatively, the L ^* value at -15° in multiple directions on the unit panel or the direction in which the L ^* value is the maximum value may be confirmed in advance, and the unit panel may be replaced based on the confirmation result. Such confirmation methods may be methods of confirming information (measured values, etc.) that has been measured and recorded in advance, or methods of confirming each time a measurement is performed.

According to the maintenance method of the spliced display device of the second embodiment of the present invention, when a part of the unit panel in the spliced display device is replaced, the color deviation of the spliced display device after the replacement can be suppressed.

Furthermore, when there are multiple adjacent unit panels relative to one unit panel to be replaced, if step B22 is performed on at least one of the adjacent unit panels, the color difference between the adjacent unit panel and the replaced unit panel is suppressed. If step B22 is performed on all adjacent unit panels, the color difference between all adjacent unit panels and the replaced unit panel is suppressed, which is better. [Implementation Example]

Hereinafter, the present invention will be specifically described with reference to embodiments, but the present invention is not limited thereto.

(Example 1, Example 2) The following Examples 1 and 2 are examples of the first embodiment as described above. Transparent substrates 1 to 3 with anti-reflection films and unit panels 1 to 3 having the same are prepared, and a spliced display device formed by combining and arranging them is evaluated. The spliced display device formed by combining unit panels 1 and 2 (the spliced display device of Example 1) is equivalent to the embodiment, and the spliced display device formed by combining unit panels 1 and 3 (the spliced display device of Example 2) is equivalent to the comparative example.

(Evaluation) (a ^＊ b ^＊ L ^＊ of diffusely reflected light at various angles) For the main surface on the display side of the unit panel or the transparent substrate alone with an anti-reflection film, the a ^＊ b ^＊ L ^＊ of diffusely reflected light at various angles was measured by the following method. The measurement on the main surface on the display side of the unit panel was performed with the screen turned off. In addition, the measurement on the transparent substrate alone with an anti-reflection film was performed by attaching a black tape (manufactured by Tomogawa Paper Co., Ltd., Clear Mierre) to the main surface (the other main surface) of the transparent substrate with an anti-reflection film that does not have a diffusion layer and an anti-reflection film, thereby removing the reflection of the other main surface. The light source was incident at an incident angle of 45° on the main surface (one main surface) of the transparent substrate with the anti-reflection film having the diffusion layer and the anti-reflection film. The reflectance of the visible light wavelength was measured for each diffuse reflection light at an angle of -15°, 15°, and 25° relative to the mirror reflection light, and a ^* , b ^* , and L ^* (diffuse reflection color) under the D65 light source were calculated. The measurement was performed using CM-M6 manufactured by Konica Minolta.

(SCI (Specular Component Include, including specular reflected light), SCE) The reflected color (L ^* , a*, and b ^{* )} of the main surface on the display side of the unit panel or the transparent substrate with an anti-reflection film is measured by the SCI method and the SCE method. Both are measured using a spectrophotometer (manufactured by Konica Minolta, trade name: CM-26d) according to the method specified in JIS Z 8722 (2009). In addition, the SCE method removes specular reflected light from the reflected light when the light contacts an object and measures only diffuse reflected light. In contrast, the SCI method measures total reflected light including specular reflected light. The measurement of the main surface on the display side of the unit panel is performed with the screen turned off. In addition, the measurement of the transparent substrate with an anti-reflection film was performed by attaching black tape (Clear Mierre, manufactured by Tomogawa Paper Co., Ltd.) to the main surface (the other main surface) of the transparent substrate with an anti-reflection film that does not have a diffusion layer and an anti-reflection film, thereby removing the reflection of the other main surface.

(Haze) The haze value (transmitted haze) of a transparent substrate with an anti-reflection film is measured in accordance with JIS K 7136:2000 using a fog meter (HZ-V3 manufactured by Suga Test Instruments).

(Visual transmittance: Y) In a transparent substrate with an anti-reflection film, the visual transmittance (Y) of the outermost surface of the anti-reflection film is measured by the method specified in JIS Z 8701 (1999). In this specification, the visual transmittance (Y) of the outermost surface of the anti-reflection film is referred to as the visual transmittance (Y) of the transparent substrate with an anti-reflection film. Specifically, a black tape is attached to the other of the two main surfaces of the transparent substrate that is not the anti-reflection film side to remove the back reflection. In this state, the spectral transmittance is measured using a spectrophotometer (manufactured by Shimadzu Corporation, trade name: SolidSpec-3700), and the visual transmittance (stimulus value Y specified in JIS Z 8701 (1999)) is calculated.

(Color deviation evaluation) 96 transparent substrates with anti-reflection films produced under the same conditions as the transparent substrate 1 with anti-reflection films in the unit panel 1 were prepared. Specifically, 96 transparent substrates with anti-reflection films produced under the conditions in the transparent substrate 1 with anti-reflection films and by slightly changing the film thickness of each layer from the conditions were prepared. Then, after affixing a black tape (manufactured by Tomogawa Paper Co., Ltd., Clear Mierre) to the main surface (the other main surface) without a diffusion layer and an anti-reflection film, they were arranged (spliced) in a vertical direction of 12 × horizontal direction without gaps. For the transparent substrates with anti-reflection films after splicing, the color deviation was visually evaluated according to the following criteria and classified into two levels of "good" and "poor". Then, prepare one "good" and one "bad" sample without black tape on the back, use the "good" sample as transparent substrate 2 with anti-reflection film for unit panel 2, and use the "bad" sample as transparent substrate 3 with anti-reflection film for unit panel 3. On the display side of the self-luminous OLED display device (Pixel 6 Pro manufactured by Google), transparent substrates 1 to 3 with anti-reflection films are bonded with a transparent adhesive in such a way that the side with the anti-reflection film becomes the display side, thereby forming unit panels 1 to 3. For each unit panel, the SCI, SCE, and diffuse reflection color at each angle are obtained. Good: When white LED lighting is reflected on the main surface (one main surface) of the transparent substrate with anti-reflection film and the side with diffusion layer and anti-reflection film, the white lighting reflected on the transparent substrate with anti-reflection film looks close to a non-color when observed from various angles, and the difference in color between the substrates is not obvious. Bad: When white LED lighting is reflected on the main surface (one main surface) of the transparent substrate with anti-reflection film and the side with diffusion layer and anti-reflection film, the difference in color with the surrounding is obvious when observed from various angles.

Next, a spliced display device of Example 1 including two unit panels is formed by arranging and configuring unit panel 1 and unit panel 2. Also, a spliced display device of Example 2 including two unit panels is formed by arranging and configuring unit panel 1 and unit panel 3. For each spliced display device, the color deviation under front view and oblique view is evaluated according to the following criteria. "No": When visually viewing the spliced display device, the difference in color tone (reflected color) between the unit panels is not felt. "Yes": When visually viewing the spliced display device, the difference in color tone (reflected color) between the unit panels is felt, and the color deviation is obvious.

Furthermore, let a ^* and b ^* of diffuse reflection light at each angle of the unit panel 1 be _ax ^* and _bx ^* , let a ^* and b ^* of diffuse reflection light at each angle of each example be _ay ^* and _byy ^* , and calculate Δa ^* b ^* at each angle in this case. Δa ^* b ^* is calculated similarly for SCI and SCE.

(Transparent substrate 1 with anti-reflection film) An anti-reflection film is formed on an anti-glare PET film having a diffusion layer formed on one main surface of the transparent substrate by the following method, thereby producing a transparent substrate with an anti-reflection film. Furthermore, as the transparent substrate, a resin substrate is provided as described below.

(Transparent substrate, diffusion layer) An anti-glare PET film with a length of 50 mm × width of 50 mm × thickness of 0.1 mm (manufactured by Liguang Co., Ltd., Sa: 0.259 μm, Sdr: 0.0620, Sdq: 0.361, Spc: 1703 (1/mm), haze value: 60%) was used.

(Film formation of barrier layer) Next, a SiN layer of the film thickness shown in Table 1 is formed on the diffusion layer as a barrier layer. For example, the film thickness of the barrier layer in Example 1 is 9 nm. The barrier layer is formed by digital sputtering using a silicon target, while maintaining the pressure at 0.2 Pa under argon gas, and performing pulse sputtering under the conditions of a frequency of 100 kHz, a power density of 10.0 W/cm ² , and a reverse pulse width of 3 μsec to form a silicon film of a very small film thickness, and then immediately nitriding it with nitrogen gas, and the above steps are repeated at a high speed to form a silicon nitride film, thereby forming a layer including silicon nitride (SiN _x ) of a specified film thickness. Here, the nitrogen flow rate during nitridation using nitrogen gas is 800 sccm, and the power of the nitridation source is 600 W.

(Film formation of anti-reflection film) Then, an anti-reflection film having the film structure shown in Table 1 is formed by alternately forming NMWO layers (high refractive index layers) and SiO layers (low refractive index layers) on the barrier layer. Furthermore, NMWO layer means a mixed oxide layer of Nb, Mo and W. For example, the film structure of the anti-reflection film of Example 1 in Table 1 means that a 4 nm NMWO layer is formed on the barrier layer, followed by a 40 nm SiO layer, followed by a 44 nm NMWO layer, followed by a 15 nm SiO layer, followed by a 46 nm NMWO layer, followed by an 87 nm SiO layer, thereby forming an anti-reflection film having a film structure of 6 layers. The film formation methods of SiO layer and NMWO layer are described as follows.

(NMWO layer formation) By digital sputtering, a target made by mixing and sintering niobarium, molybdenum and tungsten in a mass ratio of 24:30:46 was used. While maintaining the pressure at 0.2 Pa under argon, pulse sputtering was performed at a frequency of 100 kHz, a power density of 10.0 W/ ^cm2 , and a reverse pulse width of 3 μsec to form a metal film of a very small film thickness. It was then immediately oxidized using oxygen. The above steps were repeated at a high speed to form an oxide film and a NMWO layer of a specified film thickness. Furthermore, regarding the NMWO layer formed by this method, the composition was measured by X-ray photoelectron spectroscopy (XPS) depth composition analysis using argon ion sputtering. The results showed that, excluding oxygen, Nb was 31.5 at%, Mo was 38.1 at%, W was 30.5 at%, and the B group element content was 24 weight%.

(SiO layer formation) A silicon target was used for digital sputtering. While maintaining the pressure at 0.2 Pa under argon, pulse sputtering was performed at a frequency of 100 kHz, a power density of 10.0 W/cm ² , and a reverse pulse width of 3 μsec. A silicon film of a very small film thickness was formed. Then, it was immediately oxidized by oxygen. The above steps were repeated at high speed to form a silicon oxide film. A layer containing silicon oxide (SiO _x ) of a specified film thickness was formed. Here, the oxygen flow rate when oxidizing by oxygen was 500 sccm, and the power of the oxidation source was 1000 W.

(Film formation of antifouling film) KY-185 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.) is placed in a metal crucible (evaporation source) as a fluorine-containing organic silicide and heated at 230-350°C to evaporate. The evaporated particles are evaporated and diffused into a vacuum chamber where a substrate is placed, and adhere to the surface of the substrate. The evaporation rate is monitored by control based on a quartz crystal oscillator while an antifouling film with a thickness of 4 nm is formed.

(Transparent substrates 2 and 3 with anti-reflection film) Transparent substrates 2 and 3 with anti-reflection film are obtained by the same operation as transparent substrate 1 with anti-reflection film. However, due to the uneven film thickness caused by the film forming process, the film thickness of each layer in the anti-reflection film, etc. in transparent substrates 2 and 3 with anti-reflection film is slightly different from that of transparent substrate 1 with anti-reflection film.

The results of the above evaluation of transparent substrates 1 to 3 with anti-reflection films and unit panels 1 to 3 are shown in Table 1. Here, the unit panels 2 and 3 were evaluated for Δa ^* b ^* and the difference in reflected color when arranged with the unit panel 1, and the results obtained were equivalent to the results obtained by evaluating the spliced display devices of Examples 1 and 2, respectively.

[Table 1] Table 1 Transparent substrate with anti-reflection film 1/unit panel 1 Transparent substrate 2/unit panel 2 with anti-reflection film Transparent substrate 3/unit panel 3 with anti-reflection film Anti-reflection film-number of layers 6 6 6 Visual transmittance Y(D65)(%) 75 75 75 Fog penetration(%) 60 60 60 High refractive index layer NMWO NMWO NMWO Diffuse Color Green Green Green Antifouling film KY-185(nm) 4 The basic film thickness is the same as the transparent substrate 1 with anti-reflection film, but there is uneven film thickness due to the film forming process. Anti-reflective film 6 Low refractive index layer (nm) 87 5 High refractive index layer (nm) 46 4 Low refractive index layer (nm) 15 3 High refractive index layer (nm) 44 2 Low refractive index layer (nm) 40 1 High refractive index layer (nm) 4 Barrier layer SiN(nm) 9 Substrate AGPET AGPET AGPET Reflective color (transparent substrate with anti-reflective film alone) (D65) Indicators L ^* a ^* b ^* L ^* a ^* b ^* L ^* a ^* b ^* SCI 7.3 -2.1 0.6 7.0 -1.5 -0.7 10.1 -1.8 -1.6 SCE 5.9 -2.1 0.5 5.6 -1.6 -0.6 8.6 -1.8 -1.8 Diffuse reflection color (transparent substrate with anti-reflection film alone) (D65) Indicators L ^* a ^* b ^* L ^* a ^* b ^* L ^* a ^* b ^* -15° 52.9 -2.9 2.2 53.6 -0.1 0.1 58.5 -0.7 -3.3 15° 26.7 -6.3 4.2 26.8 -5.2 1.3 32.2 -5.2 -1.7 25° 13.3 -6.2 3.5 13.1 -5.0 0.9 17.8 -3.3 -1.8 45° 2.7 -2.1 0.5 2.6 -1.4 -0.3 4.3 0.7 -1.0 Color deviation Δa ^＊ b ^＊ (Transparent substrate with anti-reflection film alone) Reflection Color SCI 0.0 1.7 2.2 SCE 0.0 1.4 2.3 Diffuse Color -15° 0.0 9.8 5.9 15° 0.0 4.0 6.0 25° 0.0 1.3 3.2 The difference in reflected color when arranged with a transparent substrate 1 with an anti-reflection film Front View - without without Strabismus - have have Reflection color (unit panel) (D65) Indicators L ^* a ^* b ^* L ^* a ^* b ^* L ^* a ^* b ^* SCI 10.0 -1.9 1.4 10.2 -1.3 0.1 12.5 -2.2 0.3 SCE 7.8 -2.3 1.3 8.0 -1.7 0.0 10.5 -2.4 0.0 Diffuse color (unit panel) (D65) Indicators L ^* a ^* b ^* L ^* a ^* b ^* L ^* a ^* b ^* -15° 55.8 -1.9 3.4 55.1 -1.4 1.4 60.0 -1.5 -2.5 15° 30.6 -4.5 4.5 30.6 -5.0 2.7 35.0 -5.2 -0.5 25° 15.5 -4.8 3.8 15.3 -4.9 2.2 19.4 -3.9 -0.6 Color deviation ∆a*b*(unit panel) Reflection Color SCI 0.0 1.6 1.2 SCE 0.0 1.6 1.3 Diffuse Color -15° 0.0 2.2 5.9 15° 0.0 2.1 5.1 25° 0.0 1.6 4.5 The difference in reflected color when arranged with unit panel 1 Front View - without without Strabismus - without have

The results in Table 1 confirm that in the spliced display device (the spliced display device of Example 1) including the unit panels of Example 1 and Example 2 that have two adjacent unit panels satisfying the above-mentioned condition 1, the difference in reflection color during splicing need not be taken into consideration.

(Examples 3 to 5) The following examples 3 to 5 are examples of the second embodiment described above. Unit panels 4 to 7 are prepared respectively, and the spliced display device formed by combining and arranging them is evaluated. The spliced display device formed by combining unit panels 4 and 5 (the spliced display device of Example 3) is equivalent to the embodiment, and the spliced display device formed by combining unit panels 4 and 6 (the spliced display device of Example 4), and the spliced display device formed by combining unit panels 4 and 7 (the spliced display device of Example 5) are equivalent to the comparative example.

(Evaluation) (L ^* of diffuse reflected light) For the transparent substrate with an anti-reflection film used in each unit panel, the L ^* of diffuse reflected light was measured by the following method. Furthermore, by attaching a black tape (Clear Mierre, manufactured by Tomogawa Paper Co., Ltd.) to the main surface of the transparent substrate with an anti-reflection film on the side without a diffusion layer observed from the transparent substrate, the reflection of the main surface on the side without a diffusion layer was removed. The light source was made incident at an incident angle of 45° to the main surface (one main surface) with a diffusion layer of the transparent substrate with an anti-reflection film arranged on the display surface side of the unit panel. For each diffuse reflected light at an angle of -15° relative to the mirror reflected light, the reflectivity of the visible light wavelength was measured, and the L ^* (diffuse reflectivity) under the D65 light source was calculated. Furthermore, the measurement was performed using CM-M6 manufactured by Konica Minolta. In addition, the results measured using the spectrophotometer CM-26d manufactured by Konica Minolta were the same, but the absolute values of the L ^* values were different. One direction on the main surface of the transparent substrate with an anti-reflection film (equivalent to the 0° direction in the obtained spliced display device) was set as the 0° direction, and 36 directions were used as incident directions at intervals of 10° until the 360° direction, and the above-mentioned L ^* value was measured. From the result, the angle of the direction in which the L ^* value of each unit panel of condition 2 in the obtained spliced display device is the largest is determined.

(Unit panel 4) An anti-glare PET film (manufactured by Liguang Co., Ltd., Sa: 0.259 μm, Sdr: 0.0620, Sdq: 0.361, Spc: 1703 (1/mm), haze value: 60%) is used as an anti-glare film, and a barrier layer, an anti-reflection film, and an anti-fouling layer are formed on the diffusion layer to obtain a transparent substrate 4 with an anti-reflection film. The barrier layer, the anti-reflection film, and the anti-fouling layer are formed in the same manner as the transparent substrate 1 with an anti-reflection film. The obtained transparent substrate 4 with an anti-reflection film is attached to the display side of a self-luminous OLED display device (Pixel 6 Pro manufactured by Google). At this time, the transparent substrate 4 with the anti-reflection film is attached in such a way that the MD direction of the anti-glare film is consistent with the upper direction of the display surface of the display device when viewed from the front (hereinafter also referred to as the reference direction) to obtain the unit panel 4.

(Unit panel 5, Example 3) Anti-glare PET film (manufactured by Liguang Co., Ltd., Sa: 0.259 μm, Sdr: 0.0620, Sdq: 0.361, Spc: 1703 (1/mm), haze value: 60%) is used as an anti-glare film, and a barrier layer, an anti-reflection film and an anti-fouling layer are formed on the diffusion layer to obtain a transparent substrate 5 with an anti-reflection film. The barrier layer, the anti-reflection film and the anti-fouling layer are formed in the same manner as the transparent substrate 4 with an anti-reflection film. The obtained transparent substrate 5 with an anti-reflection film is attached to the display side of a self-luminous OLED display device (Pixel 6 Pro manufactured by Google). At this time, the transparent substrate 5 with an anti-reflection film is bonded in such a manner that the MD direction of the anti-glare film is consistent with the upper direction (reference direction) of the display surface of the display device when viewed from the front, thereby obtaining a unit panel 5. The unit panels 4 and 5 are arranged adjacent to each other, thereby obtaining the spliced display device of Example 3. Furthermore, the shape of the main surface of the unit panels 4 to 7 is roughly rectangular, and in the spliced display devices of Examples 3 to 5, the two adjacent unit panels are arranged to share a side at their junction. Furthermore, in each spliced display device, the unit panels are arranged in such a manner that the reference direction when the transparent substrate with an anti-reflection film is bonded to each unit panel becomes the same direction within one spliced display device. That is, in the spliced display device of Example 3, the arrangement is performed in such a way that the reference direction in unit panel 4 and the reference direction in unit panel 5 are the same direction (for example, the upper direction is the bottom direction when viewed from the front of the main surface of the spliced display device).

(Unit panel 6, Example 4) A transparent substrate 5 with an anti-reflection film is used and bonded to the display surface of a self-luminous OLED display device (Pixel 6 Pro manufactured by Google). At this time, the MD direction of the anti-glare film is rotated 90° clockwise relative to the upper direction (reference direction) of the display surface of the display device in the front view, and the transparent substrate 5 with an anti-reflection film is bonded to obtain a unit panel 6. The unit panels 4 and 6 are arranged in an adjacent manner to obtain the spliced display device of Example 4.

(Unit panel 7, Example 5) A transparent substrate 5 with an anti-reflection film is used and bonded to the display surface of a self-luminous OLED display device (Pixel 6 Pro manufactured by Google). At this time, the MD direction of the anti-glare film is rotated 180° clockwise relative to the upper direction (reference direction) of the display surface of the display device in the front view, and the transparent substrate 5 with an anti-reflection film is bonded to obtain a unit panel 7. The unit panels 4 and 7 are arranged in an adjacent manner to obtain the spliced display device of Example 5.

(Evaluation results) The results of the above measurements of each spliced display device are shown in Figures 8 to 10. That is, Figure 8 is a graph showing the above L ^* values of 36 directions of each unit panel (unit panels 4 and 5) in the spliced display device of Example 3, Figure 9 is a graph showing the above L ^* values of 36 directions of each unit panel (unit panels 4 and 6) in the spliced display device of Example 4, and Figure 10 is a graph showing the above L ^* values of 36 directions of each unit panel (unit panels 4 and 7) in the spliced display device of Example 5. Furthermore, the measured value of the L ^* value itself is a value obtained by measuring the transparent substrate with an anti-reflection film used in each unit panel separately. However, even if the same measurement is performed in the state of forming a unit panel, the directivity of the L ^* value determined by the incident direction does not change. In the spliced display device of Example 3, the angle of the direction in which the L ^* value of unit panel 4 is the largest is 350°, and the maximum value of L ^* is 54.56. The angle of the direction in which the L ^* value of unit panel 5 is the largest is 10°, and the maximum value of L ^* is 54.32. The difference in the angles of the directions in which the L ^* value is the largest is 20°. In the spliced display device of Example 4, the angle of the direction in which the L ^* value of unit panel 4 is the largest is 350°, and the maximum value of L ^* is 54.56. The angle of the direction in which the L ^* value of unit panel 6 is the largest is 100°, and the maximum value of L ^* is 54.32. The difference in the angles in the directions in which the L ^* value is the largest is 120°. In the spliced display device of Example 5, the angle of the direction in which the L ^* value of unit panel 4 is the largest is 350°, and the maximum value of L ^* is 54.56. The angle of the direction in which the L ^* value of unit panel 7 is the largest is 190°, and the maximum value of L ^* is 54.32. The difference in the angles in the directions in which the L ^* value is the largest is 160°.

When visually inspecting the spliced display device of Example 3, no difference in color tone (reflected color) between the unit panels was felt, regardless of whether it was viewed from the front or from the side. When visually inspecting the spliced display devices of Examples 4 and 5 from various angles, the difference in color tone (reflected color) between the unit panels was felt, and the color deviation was obvious.

In the above, various embodiments are described with reference to the drawings, but the present invention is of course not limited to the above examples. The industry can obviously think of various changes or modifications within the scope of the invention application, and it is clear that they also naturally belong to the technical scope of the present invention. In addition, the various components in the above embodiments can be arbitrarily combined within the scope of the invention.

Furthermore, this application is based on Japanese patent applications filed on April 8, 2022 (Japanese Patent Application No. 2022-064751), Japanese patent applications filed on April 8, 2022 (Japanese Patent Application No. 2022-064752), Japanese patent applications filed on July 13, 2022 (Japanese Patent Application No. 2022-112709), and Japanese patent applications filed on November 29, 2022 (Japanese Patent Application No. 2022-190437), and the contents thereof are incorporated herein by reference.

1: Transparent substrate with anti-reflection film 1a, 1b: Transparent substrate with anti-reflection film 5: Unit panel 5a, 5b: Unit panel 7: Main body 7a, 7b: Main body 10: Transparent substrate 11: One main surface 12: Another main surface 20: Black tape 30: Anti-reflection film 31: Diffusion layer 32: First dielectric layer 34: Second dielectric layer 50: Light source 60: Incident light 61: Mirror reflection light 71, 72, 73, 74, 75, 76: Diffuse reflection light 80: Incident light 81: Diffuse reflection light 100: Spliced display device 200: Spliced display device 201: Anti-glare film 201a, 201b: Anti-glare film 205: Unit panel 205a: Unit panel 205b: Unit panel 207: Main body 207a, 207b: Main body 210: Resin matrix 231: Diffusion layer D1: 0° direction S: The edge shared by two adjacent unit panels P: Projection trajectory

Figure 1 is a perspective view schematically showing a configuration example of a spliced display device according to the first embodiment of the present invention. Figure 2 is a cross-sectional view schematically showing a configuration example of a transparent substrate with an anti-reflection film in a unit panel. Figure 3 is a schematic diagram illustrating a method for measuring a ^* and b ^* of diffusely reflected light at various angles under condition 1. Figure 4 is a schematic diagram illustrating a method for measuring a ^* and b ^* of diffusely reflected light at various angles under conditions A to D. Figure 5 is a perspective view schematically showing a configuration example of a spliced display device according to the second embodiment of the present invention. Figure 6 is a cross-sectional view schematically showing a configuration example of a unit panel with an anti-glare film. Figure 7 is a diagram schematically showing a measurement method under condition 2. Figure 8 is a diagram showing the measurement results under condition 2 of the spliced display device of Example 3. Fig. 9 is a diagram showing the measurement results of the splicing display device of Example 4 under Condition 2. Fig. 10 is a diagram showing the measurement results of the splicing display device of Example 5 under Condition 2.

1a, 1b: Transparent substrate with anti-reflection film

5a,5b: Unit panel

7a,7b: Body part

100:Splicing display device

Claims (10)

A spliced display device is formed by arranging a plurality of unit panels having a transparent substrate with an anti-reflection film on the display surface side, and the transparent substrate with the anti-reflection film has a transparent substrate, a diffusion layer and an anti-reflection film in sequence facing the display surface side, and two adjacent unit panels meet the following condition 1; (Condition 1) when a light source is incident on the main surface of the display surface side of one of the two unit panels at an incident angle of 45°, a ^* and b ^* of diffusely reflected light under a D65 light source at angles of -15°, 15° and 25° relative to the mirror reflected light are set as _ax ^* and _bx * at each angle, and a ^* and b ^* measured in the same manner for the other unit panel are set as _ay ^* and _byy at each angle ^. When Δa ^* b ^* is less than 3.0 at each angle, Δa ^* b ^* =(( _ax ^* - _ay ^* ) ² +( _bx ^* - _by ^* ) ^{2 ) 1/2} . As in claim 1, the splicing display device, wherein the haze value of the transparent substrate with the anti-reflection film is greater than 30%. A unit panel group is used for a spliced display device formed by arranging a plurality of unit panels having a transparent substrate with an anti-reflection film on the display surface side, and the transparent substrate with the anti-reflection film has a transparent substrate, a diffusion layer and an anti-reflection film in sequence facing the display surface side, and two unit panels randomly selected from the unit panel group meet the following condition 1; (Condition 1) when a light source is incident on the main surface of the display surface side of one of the two unit panels at an incident angle of 45°, a ^* and b ^* of diffuse reflected light under a D65 light source at angles of -15°, 15° and 25° relative to the mirror reflected light are set as _ax ^* and _bx ^* at each angle, and a ^* and b ^* similarly measured for the other unit panel are set as _ay * at each angle. When Δa ^* b ^* and _by ^* are equal, Δa*b ^* at each angle is less than 3.0, Δa ^* b ^* =((a _x ^* - a _y ^* ) ² +(b _x ^* - _by ^* ) ² ) ^1/2 . As in the unit panel group of claim 3, the haze value of the transparent substrate with the anti-reflection film is above 30%. A method for manufacturing a spliced display device, which is a method for manufacturing a spliced display device formed by arranging a plurality of unit panels having a transparent substrate with an anti-reflection film on the display side, and includes: for the plurality of the unit panels, confirming a ^* and b* of diffuse reflection light under a D65 light source at angles of -15°, 15° and 25° relative to mirror reflection light when the light source is incident on the main surface of the display side at an incident angle of 45 ^° ; and selecting a combination of unit panels that meets the following condition 1, and arranging the unit panels belonging to the above combination in a manner that they are adjacent to each other; (Condition 1) When light is incident on the main surface of the display surface side of one of the two unit panels at an incident angle of 45°, a ^* and b ^* of diffuse reflected light under a D65 light source at angles of -15°, 15° and 25° with respect to the mirror reflected light are set as _ax ^* and _bx ^* at each angle, and a ^* and b ^* measured in the same manner for the other unit panel are set as _ay ^* and _byy ^* at each angle, Δa ^* b ^* at each angle is less than 3.0, Δa ^* b ^* =(( _ax ^* _-ay ^* ) ² +( _bx ^* _-by ^* ) ² ) ^1/2 . A maintenance method for a spliced display device, which is a maintenance method for a spliced display device formed by arranging a plurality of unit panels having a transparent substrate with an anti-reflection film on the display side, and includes: selecting a unit panel to be replaced from the unit panels constituting the spliced display device; for at least one adjacent unit panel adjacent to the above-mentioned unit panel to be replaced, confirming a* and b* under a D65 light source of diffuse reflection light at angles of -15 ^° , 15° and 25° relative to mirror reflection light when the light source is incident on the main surface of the display side at an incident angle of 45 ^° ; and replacing the above-mentioned unit panel to be replaced in a manner that the replaced unit panel satisfies the following condition 1 relative to the above-mentioned adjacent unit panel; (Condition 1) When light is incident on the main surface of the display surface side of one of the two unit panels at an incident angle of 45°, a ^* and b ^* of diffuse reflected light under a D65 light source at angles of -15°, 15° and 25° with respect to the mirror reflected light are set as _ax ^* and _bx ^* at each angle, and a ^* and b ^* measured in the same manner for the other unit panel are set as _ay ^* and _byy ^* at each angle, Δa ^* b ^* at each angle is less than 3.0, Δa ^* b ^* =(( _ax ^* _-ay ^* ) ² +( _bx ^* _-by ^* ) ² ) ^1/2 . A spliced display device as claimed in claim 1 or 2, wherein the transparent substrate with an anti-reflection film comprises an anti-glare film as the diffusion layer and the transparent substrate, and the two adjacent unit panels satisfy the following condition 2; (Condition 2) The difference between the angle of the direction in which the L ^* value of one of the two adjacent unit panels is the maximum and the angle of the direction in which the L ^* value of the other unit panel measured in the same manner is the maximum is 35° or less; (Method) On a surface parallel to the main surface of the spliced display device, one of the directions parallel to the common side of the two adjacent unit panels is set as the 0° direction; on one hand, the incident direction is changed from the 0° direction to the 360° direction at intervals of 10°, and on the other hand, the light source is incident on the main surface of the display surface side of the unit panel as the measurement object at an incident angle of 45°; for each incident direction, the L ^* value of the diffusely reflected light under the D65 light source at an angle of -15° relative to the mirror reflected light of the incident light is measured, and the angle of the incident direction with the maximum L ^* value is taken as the angle of the direction with the maximum L ^* value with respect to the unit panel of the measurement object. A spliced display device is formed by arranging a plurality of unit panels having an anti-glare film on the display side, and two adjacent unit panels satisfy the following condition 2; (Condition 2) The difference between the angle of the direction in which the L ^* value of one of the two adjacent unit panels is the maximum and the angle of the direction in which the L ^* value of the other unit panel measured in the same manner is the maximum is 35° or less; (Method) On a surface parallel to the main surface of the spliced display device, one of the directions parallel to the common side of the two adjacent unit panels is set as the 0° direction; on one hand, the incident direction is changed from the 0° direction to the 360° direction at intervals of 10°, and on the other hand, the light source is incident on the main surface of the display surface side of the unit panel as the measurement object at an incident angle of 45°; for each incident direction, the L ^* value of the diffusely reflected light under the D65 light source at an angle of -15° relative to the mirror reflected light of the incident light is measured, and the angle of the incident direction with the maximum L ^* value is taken as the angle of the direction with the maximum L ^* value with respect to the unit panel of the measurement object. A method for manufacturing a spliced display device, which is a method for manufacturing a spliced display device formed by arranging a plurality of unit panels having an anti-glare film on the display side, and includes arranging the unit panels in a manner that the adjacent unit panels satisfy the following condition 2: (Condition 2) The difference between the angle in the direction in which the L ^* value of one of the two adjacent unit panels is the maximum and the angle in the direction in which the L ^* value of the other unit panel measured in the same manner is the maximum is 35° or less; (Method) On a surface parallel to the main surface of the spliced display device, one of the directions parallel to the common side of the two adjacent unit panels is set as the 0° direction; on one hand, the incident direction is changed from the 0° direction to the 360° direction at intervals of 10°, and on the other hand, the light source is incident on the main surface of the display surface side of the unit panel as the measurement object at an incident angle of 45°; for each incident direction, the L ^* value of the diffusely reflected light under the D65 light source at an angle of -15° relative to the mirror reflected light of the incident light is measured, and the angle of the incident direction with the maximum L ^* value is taken as the angle of the direction with the maximum L ^* value with respect to the unit panel of the measurement object. A maintenance method for a spliced display device, which is a maintenance method for a spliced display device formed by arranging a plurality of unit panels with anti-glare films on the display side, and includes: selecting a unit panel to be replaced from the unit panels constituting the spliced display device; and replacing the unit panel to be replaced in a manner such that the replaced unit panel satisfies the following condition 2 relative to at least one adjacent unit panel adjacent to the unit panel to be replaced; (Condition 2) The difference between the angle in the direction in which the L ^* value of one of the two adjacent unit panels is the maximum, obtained by the following method, and the angle in the direction in which the L ^* value of the other unit panel is the maximum, measured in the same manner, is less than 35°; (Method) On a surface parallel to the main surface of the spliced display device, one of the directions parallel to the common side of the two adjacent unit panels is set as the 0° direction; on one hand, the incident direction is changed from the 0° direction to the 360° direction at intervals of 10°, and on the other hand, the light source is incident on the main surface of the display surface side of the unit panel as the measurement object at an incident angle of 45°; for each incident direction, the L ^* value of the diffusely reflected light under the D65 light source at an angle of -15° relative to the mirror reflected light of the incident light is measured, and the angle of the incident direction with the maximum L ^* value is taken as the angle of the direction with the maximum L ^* value with respect to the unit panel of the measurement object.