Laminated member, LED backlight and display device

Abstract

The invention provides a laminated member, an LED backlight, and a display device. A diffusion member has, in order, a first layer having light transmissivity and light diffusivity, and a second layer having a reflectivity that increases as the absolute value of the angle of incidence of light with respect to the surface of the second layer on the first layer side decreases, the first layer having light diffusivity and the second layer having light diffusivity, and the second layer having light diffusivity and light diffusivity that increases as the absolute value of the angle of incidence of light with respect to the surface of the second layer on the first layer side decreases. The transmittance increases as the absolute value of the incident angle of light with respect to the surface of the second layer on the first layer side increases.

Description

[0001] This application is a divisional application of the Chinese invention patent application with an application date of June 23, 2020, an invention name of “Diffusion component, laminate, group of diffusion components, LED backlight source and display device”, and an application number of 202080045890.1 (PCT / JP2020 / 024644). Technical Field

[0002] The present disclosure relates to a stacked component, an LED backlight, and a display device. Background Art

[0003] In recent years, display devices such as liquid crystal display devices that use LED backlights as light sources have rapidly become popular.

[0004] Here, LED backlights are roughly divided into direct-lit and edge-lit types. Edge-lit LED backlights are usually used in small and medium-sized display devices such as smartphones and other portable terminals, but direct-lit LED backlights are being studied from the perspective of brightness. On the other hand, direct-lit LED backlights are often used in large display devices such as large-screen LCD TVs.

[0005] A direct-type LED backlight has a structure in which a plurality of LED elements are arranged on a substrate. In such a direct-type LED backlight, by independently controlling a plurality of LED elements, the brightness of each area of ​​the LED backlight can be adjusted according to the brightness of the displayed image, so-called local dimming. This can significantly improve the contrast of the display device and reduce power consumption.

[0006] In a direct-type LED backlight, a diffusion plate is disposed above the LED element from the viewpoint of suppressing uneven brightness.

[0007] Prior art literature

[0008] Patent Literature

[0009] Patent Document 1: Japanese Patent Application Publication No. 2018-67441

[0010] Patent Document 2: Japanese Patent Application Publication No. 2017-92021

[0011] Patent Document 3: Japanese Patent No. 5062408

[0012] Patent Document 4: Japanese Patent Application Publication No. 2019-61954 Summary of the invention

[0013] Problems to be solved by the invention

[0014] However, in order to suppress uneven brightness in direct-type LED backlight sources, it is necessary to configure the LED elements and the diffusion plate separately. Therefore, it is difficult to achieve thinness. In particular, when the number of LED elements is reduced in order to reduce costs and power consumption, the configuration interval of the LED elements is enlarged, so uneven brightness is likely to occur. In this case, it is necessary to further extend the distance between the LED elements and the diffusion plate, so thinning becomes more difficult. Therefore, in existing direct-type LED backlight sources, there is a problem that it is difficult to achieve both uniform brightness and thinness at the same time.

[0015] In addition, in order to improve the in-plane uniformity of brightness, a solution has been proposed to further arrange a transmissive reflective plate between the LED element and the diffuser plate (for example, see Patent Document 1). The transmissive reflective plate has a patterned reflective portion and a transmissive portion, and more specifically, has a pattern in which the portion directly above the LED element is used as the reflective portion, and the transmissive portion gradually increases from the portion directly above the LED element toward the periphery. As a result, the light directly above the LED element can be reflected and diffused to the periphery, and emitted from the transmissive portion in the periphery, thereby improving the in-plane uniformity of brightness.

[0016] However, even when such a transflective plate is used, in order to suppress uneven brightness, the LED element and the transflective plate need to be separately arranged, so it is difficult to achieve thinning. In addition, since the transflective plate has a patterned reflective portion and a transmissive portion, and the reflective portion is arranged directly above the LED element, it is necessary to align the LED element with the transflective plate.

[0017] In addition, in order to achieve uniform brightness and thinness, the following solution is proposed in, for example, Patent Document 2: a half-mirror that reflects part of the incident light and allows part to pass through is arranged between the LED element and the diffuser, and as the half-mirror, a half-mirror whose reflectivity at oblique incidence is lower than that at vertical incidence is used.

[0018] Furthermore, in order to achieve uniform brightness, for example, the following solution is proposed in Patent Document 3: a backlight diffraction optical element is arranged between the LED element and the diffuser, and the backlight diffraction optical element transmits and diffracts light from the light source, and emits transmitted diffraction light with a ring-shaped intensity distribution in which the intensity of the transmitted diffraction light emitted at the peripheral portion is stronger than the intensity of the transmitted diffraction light emitted at the center of the optical axis and is greater than 0.

[0019] The present disclosure has been made in view of the above-mentioned actual situation, and its main object is to provide a diffusion member, a laminate, a diffusion member group, an LED backlight, and a display device that can improve the in-plane uniformity of brightness and achieve thinning.

[0020] Means for solving problems

[0021] The inventors of the present invention have conducted intensive research to solve the above-mentioned problems and have found that by combining a layer having light transmittance and light diffusing properties with a layer whose reflectivity and transmittance have incident angle dependence and use them as a diffusion component, it is possible to improve the in-plane uniformity of brightness while achieving thinness, thereby completing the present invention.

[0022] That is, one embodiment of the present disclosure provides a diffusion component, which has a first layer and a second layer in sequence, wherein the first layer has light transmittance and light diffusion, and with respect to the second layer, the reflectivity increases as the absolute value of the incident angle of light relative to the surface of the second layer on the side of the first layer decreases, and the transmittance increases as the absolute value of the incident angle of light relative to the surface of the second layer on the side of the first layer increases.

[0023] Another embodiment of the present disclosure provides a diffusion member having a transmission type diffraction grating or a microlens array, and a dielectric multilayer film.

[0024] Another embodiment of the present disclosure provides a laminated body comprising: the above-mentioned diffusion member; and a sealing material sheet disposed on the first layer side of the diffusion member for sealing an LED element, wherein the sealing material sheet is composed of a sealing material composition containing a thermoplastic resin.

[0025] Another embodiment of the present disclosure provides a stacked body comprising: the above-mentioned diffusion component; and a sealing material sheet, which is arranged on the surface side of the transmission diffraction grating side or the microlens array side of the above-mentioned diffusion component and is used to seal the LED element, and the above-mentioned sealing material sheet is composed of a sealing material composition containing a thermoplastic resin.

[0026] Another embodiment of the present disclosure provides a group of diffusion components, which comprises: a first component, which has a first layer and a sealing material sheet for sealing an LED element; and a second component, which has a second layer and is used by being arranged on the surface of the first layer side of the above-mentioned first component via a gap portion, the above-mentioned first layer has light transmittance and light diffusion properties, and with respect to the above-mentioned second layer, as the absolute value of the incident angle of light relative to the surface of the above-mentioned second layer on the side of the above-mentioned first layer becomes smaller, the reflectivity becomes larger, and as the absolute value of the incident angle of light relative to the surface of the above-mentioned second layer on the side of the above-mentioned first layer becomes larger, the transmittance becomes larger, and the above-mentioned sealing material sheet is composed of a sealing material composition containing a thermoplastic resin.

[0027] Another embodiment of the present disclosure provides an LED backlight source, comprising: an LED substrate having a plurality of LED elements arranged on a surface side of a supporting substrate; and a diffusion component arranged on a surface side of the LED substrate on the LED element side, and having a first layer and a second layer in sequence from the LED substrate side, the first layer having light transmittance and light diffusion properties, and with respect to the second layer, the reflectivity increases as the absolute value of the incident angle of light relative to the surface of the second layer on the side of the first layer decreases, and the transmittance increases as the absolute value of the incident angle of light relative to the surface of the second layer on the side of the first layer increases.

[0028] Another embodiment of the present disclosure provides an LED backlight source, comprising: an LED substrate, which has a plurality of LED elements arranged on a surface side of a supporting substrate; and a diffusion component, which is arranged on the surface side of the LED substrate on the side of the LED elements, and the diffusion component has a transmission type diffraction grating or a microlens array, and a dielectric multilayer film in sequence from the LED substrate side.

[0029] The present disclosure provides a display device including a display panel and the above-mentioned LED backlight disposed on the back side of the display panel.

[0030] Effects of the Invention

[0031] The present disclosure has the effect of providing a diffusion member, an LED backlight, and a display device that can improve the in-plane uniformity of brightness and achieve thickness reduction. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a schematic cross-sectional view illustrating a diffusion member according to the present disclosure.

[0033] Figure 2 This is a schematic cross-sectional view illustrating an LED backlight according to the present disclosure.

[0034] Figure 3 It is a diagram for explaining the diffusion angle.

[0035] Figure 4 It is a diagram for explaining the light diffusibility of the present disclosure.

[0036] Figure 5 It is a diagram for explaining the light diffusibility of the present disclosure.

[0037] Figure 6 It is a schematic cross-sectional view illustrating a transmission-type diffraction grating of the present disclosure.

[0038] Figure 7 This is a schematic cross-sectional view illustrating a diffusion member according to the present disclosure.

[0039] Figure 8It is a schematic top view and a cross-sectional view illustrating the reflection structure of the present disclosure.

[0040] Fig. 9 It is a schematic top view and a cross-sectional view illustrating the reflection structure of the present disclosure.

[0041] Fig.10 This is a schematic cross-sectional view illustrating the reflective structure of the present disclosure.

[0042] Fig.11 This is a schematic cross-sectional view illustrating a diffusion member according to the present disclosure.

[0043] Fig.12 This is a schematic cross-sectional view illustrating a laminated body of the present disclosure.

[0044] Fig.13 The following is a process diagram illustrating a method for manufacturing the LED backlight of the present disclosure.

[0045] Fig.14 The following is a process diagram illustrating a method for manufacturing the LED backlight of the present disclosure.

[0046] Fig.15 This is a schematic cross-sectional view illustrating a laminated body of the present disclosure.

[0047] Fig.16 This is a schematic cross-sectional view illustrating a laminated body of the present disclosure.

[0048] Fig.17 This is a schematic cross-sectional view illustrating a laminated body of the present disclosure.

[0049] Fig.18 It is a schematic cross-sectional view illustrating a set of diffusion members according to the present disclosure.

[0050] Fig.19 This is a schematic cross-sectional view illustrating an LED backlight according to the present disclosure.

[0051] Fig. 20 This is a schematic cross-sectional view illustrating an LED backlight according to the present disclosure.

[0052] Fig.21 This is a schematic cross-sectional view illustrating an LED backlight according to the present disclosure.

[0053] Fig. 22 This is a schematic cross-sectional view illustrating an LED backlight according to the present disclosure.

[0054] Fig.23 is a schematic diagram illustrating a display device of the present disclosure.

[0055] Fig.24 is a schematic diagram illustrating a display device of the present disclosure.

[0056] Fig.25Graph showing the incident angle dependence of the reflectance and transmittance of the second layer of the diffusion member of Test Example 1.

[0057] Fig.26 This is the optical simulation result of Experimental Example 1.

[0058] Fig. 27 This is the optical simulation result of Experimental Example 2.

[0059] Fig.28 Graph showing the relationship between the position of the through hole of the transflective plate in Test Example 3 and the aperture ratio.

[0060] Fig.29 This is the result of the optical simulation of Experimental Example 3.

[0061] Fig.30 This is the result of the optical simulation of Experimental Example 4. DETAILED DESCRIPTION

[0062] The following is a description of the diffusion component, LED backlight source, and display device of the present disclosure. The present disclosure can be implemented in a plurality of different ways, and is not limited to the description of the following exemplary embodiments. In addition, in order to make the description clearer, the width, thickness, shape, etc. of each component are sometimes schematically indicated compared to the embodiment, but this is only an example and does not limit the interpretation of the present disclosure. In addition, in this specification and each figure, the same figure mark is marked for the same elements as those described in the figures that have already appeared, and the detailed description is sometimes appropriately omitted.

[0063] In this specification, when describing the manner of configuring other components above or below a certain component, when it is only described as the "face side", unless otherwise specified, it includes both the case where the other components are configured directly above or below the certain component in contact with the certain component, and the case where the other components are further configured above or below the certain component with another component between them.

[0064] In addition, in this specification, "LED" means a light emitting diode.

[0065] In addition, in this specification, the terms such as "sheet", "film", and "plate" are not distinguished from each other only based on the difference in name. For example, "sheet" is used to mean that it also includes a member also called a film or a plate.

[0066] A.Diffusion components

[0067] The diffusion member of the present disclosure has two embodiments. Each embodiment will be described below.

[0068] I. First Embodiment of Diffuser Member

[0069] The first embodiment of the diffusion component disclosed in the present invention is a component having a first layer and a second layer in sequence, wherein the first layer has light transmittance and light diffusibility, and with respect to the second layer, as the absolute value of the incident angle of light relative to the surface of the second layer on the first layer side becomes smaller, the reflectivity becomes larger, and as the absolute value of the incident angle of light relative to the surface of the second layer on the first layer side becomes larger, the transmittance becomes larger. The diffusion component disclosed in the present invention uses the surface on the first layer side as the incident surface of light when it is used.

[0070] Hereinafter, a first embodiment of the diffusion member of the present disclosure will be described with reference to the drawings. Figure 1 1 is a schematic cross-sectional view showing an example of a first embodiment of the diffusion component of the present disclosure. Figure 1 As shown in the example, the diffusion member 1 has the first layer 2 and the second layer 3 in this order. The first layer 2 has light transmittance and light diffusion properties, and transmits and diffuses the light L1 and L2 incident from the surface 2A on the side opposite to the surface on the second layer 3 side of the first layer 2. In addition, with respect to the second layer 3, as the absolute value of the incident angle of the light relative to the surface 3A on the first layer 2 side of the second layer 3 becomes smaller, the reflectivity becomes larger, and as the absolute value of the incident angle of the light relative to the surface 3A on the first layer 2 side of the second layer 3 becomes larger, the transmittance becomes larger. Therefore, in the second layer 3, the light L1 incident at a low incident angle θ1 relative to the surface 3A on the first layer 2 side of the second layer 3 can be reflected, and the light L2 incident at a high incident angle θ2 relative to the surface 3A on the first layer 2 side of the second layer 3 can be transmitted. It should be noted that the low incident angle refers to an incident angle with a small absolute value of the incident angle, and the high incident angle refers to an incident angle with a large absolute value of the incident angle.

[0071] Figure 2 is a schematic cross-sectional view showing an example of a direct-type LED backlight including a diffusion member according to a first embodiment of the present disclosure, and Figure 1 An example of a diffuser component is shown in FIG. Figure 2 As shown in the example, the LED backlight 10 includes: an LED substrate 11, on which an LED element 13 is arranged on one surface of a support substrate 12; and a diffusion member 1, which is arranged on the surface side of the LED substrate 11 on the side of the LED element 13. The diffusion member 1 is arranged in such a way that the surface 1A on the side of the first layer 2 faces the LED substrate 11. Figure 2 In the embodiment, the LED substrate 11 is arranged separately from the diffusion member 1 .

[0072] In this disclosure, Figure 1 As shown, the light incident from the surface 1A on the first layer 2 side of the diffusion member 1 is diffused in the first layer 2, and the light L1 incident at a low incident angle θ1 with respect to the surface 3A on the first layer 2 side of the second layer 3 among the light diffused through the first layer 2 is diffused. Figure 2As shown, it can be reflected on the surface 3A on the first layer 2 side of the second layer 3 and incident on the first layer 2 again to be diffused. Moreover, among the light diffused through the first layer 2, the light L2 and L2' incident at a high incident angle θ2 relative to the surface 3A on the first layer 2 side of the second layer 3 can be made to pass through the second layer 3 and be emitted from the surface 1B on the second layer 3 side of the diffusion component 1. In addition, by combining the first layer and the second layer, the light incident from the surface on the first layer side of the diffusion component, especially the light incident from the surface on the first layer side of the diffusion component at a low incident angle, can be made to pass through the first layer multiple times and diffuse, so that it can be emitted from the surface on the second layer side of the diffusion component at a high exit angle. Therefore, when the diffusion component disclosed in the present invention is used for a direct-type LED backlight, the light emitted from the LED element can be diffused to the entire light-emitting surface, thereby improving the in-plane uniformity of the brightness.

[0073] In addition, in the present disclosure, as described above, by combining the first layer and the second layer, light incident from the surface of the first layer side of the diffusion component at a low incident angle can be transmitted through the first layer multiple times, thereby extending the optical path length from the light incident from the surface of the first layer side of the diffusion component to the light emitted from the surface of the second layer side of the diffusion component. As a result, a portion of the light emitted from the surface of the second layer side of the diffusion component after being emitted from the LED element can be emitted from a position away from the LED element in the in-plane direction, rather than being emitted from directly above the LED element. Therefore, in a direct-down LED backlight source having a diffusion component of the present invention, even when the distance between the LED element and the diffusion component is shortened, uneven brightness can be suppressed. Therefore, thinness can be achieved while improving the in-plane uniformity of brightness. In addition, even when the number of LED elements is reduced, uneven brightness can be suppressed. Therefore, uniform brightness, thinness, low cost and low power consumption can be achieved at the same time.

[0074] In addition, the diffusion member of the present disclosure is different from the conventional transflective plate and does not need to be aligned with the LED element. Therefore, by using the diffusion member of the present disclosure, the LED backlight can be easily manufactured.

[0075] Hereinafter, a first embodiment of the diffusion member of the present disclosure will be described in detail.

[0076] 1. Layer 1

[0077] The first layer of the present disclosure is a member that is disposed on one surface side of a second layer described later and has light transmittance and light diffusibility.

[0078] As for the light transmittance of the first layer, for example, the total light transmittance of the first layer is preferably 50% or more, preferably 70% or more, and particularly preferably 90% or more. By setting the total light transmittance of the first layer within the above range, when the diffusion component of the present disclosure is used for an LED backlight, the brightness can be improved.

[0079] It should be noted that the total light transmittance of the first layer can be measured, for example, by a method in accordance with JIS K7361-1: 1997. As a light source, CIE standard light source D65 can be used.

[0080] The light diffusivity of the first layer may be, for example, light diffusivity that diffuses light randomly or light diffusivity that diffuses light mainly in a specific direction. Light diffusivity that diffuses light mainly in a specific direction is a property that deflects light, that is, a property that changes the direction of travel of light. Among them, the light diffusivity of the first layer is preferably light diffusivity that diffuses light mainly in a specific direction. By deflecting light in a predetermined direction, that is, controlling the direction of travel of light, light can be shaped into an arbitrary shape or an arbitrary intensity distribution, and the in-plane uniformity of brightness can be further improved.

[0081] As the light diffusivity of the first layer, in the case of light diffusivity that randomly diffuses light, for example, the diffusion angle of light incident on the first layer can be set to be greater than 10°, greater than 15°, or greater than 20°. In addition, the diffusion angle of light incident on the first layer can be set to be less than 85°, less than 60°, or less than 50°. By making the above-mentioned diffusion angle within the above-mentioned range, when the diffusion component disclosed in the present invention is used for an LED backlight source, the in-plane uniformity of the brightness can be improved.

[0082] Here, the diffusion angle will be described. Figure 3 1 is a graph illustrating the intensity distribution of transmitted light and is a diagram for explaining the diffusion angle. In this specification, when light is vertically incident on one surface of the first layer constituting the diffusion component, the maximum transmitted light intensity I of the light emitted from the other surface of the first layer is max The difference between the two angles, that is, the full width at half maximum (FWHM), is defined as the diffusion angle α.

[0083] It should be noted that the diffusion angle can be measured using a goniophotometer or an goniospectrocolorimeter. For example, a goniophotometer (goniometer) GP-200 manufactured by Murakami Color Research Laboratory can be used for the measurement of the diffusion angle.

[0084] In addition, as the light diffusivity of the first layer, in the case of light diffusivity that diffuses light mainly in a specific direction, the shape and intensity distribution of the light transmitted through the first layer are not particularly limited and can be appropriately selected according to the light distribution characteristics of the light source, the shape and intensity distribution of the target light, etc. As the light diffusivity of the first layer, for example, the property of emitting light having a non-Gaussian intensity distribution can be listed, and specifically, the property of emitting light having a ring-shaped intensity distribution and the property of emitting light having a top-hat-shaped intensity distribution can be listed. Figure 4 (a) and (b) are examples of ring-shaped intensity distribution. Figure 5 is an example of a top-hat-shaped intensity distribution.

[0085] The light diffusibility of the first layer is preferably a property of emitting light having a ring-shaped intensity distribution. In particular, the light diffusibility of the first layer is a property of emitting light having a ring-shaped intensity distribution, for example Figure 4 As shown in (a), the intensity of the transmitted light emitted at the center of the optical axis is preferably substantially zero. Light incident from the surface on the first layer side of the diffusion component can be diffused into a ring shape in the first layer, and light incident at a low incident angle relative to the surface on the first layer side of the second layer can be reflected on the surface on the first layer side of the second layer and incident on the first layer again to be diffused into a ring shape. By repeating this operation, light incident from the surface on the first layer side of the diffusion component can be expanded in the lateral direction. Therefore, when the diffusion component disclosed in the present invention is used for a direct-type LED backlight source, light emitted from the LED element can be diffused to the entire light-emitting surface, the in-plane uniformity of brightness can be further improved, and there is no need to align with the LED element.

[0086] Here, the intensity distribution can be measured using a goniophotometer or a goniospectrocolorimeter.

[0087] As the first layer, there is no particular limitation as long as it has the above-mentioned light transmittance and light diffusivity, and various structures having the above-mentioned light transmittance and light diffusivity can be adopted. As the first layer, for example, a transmission type diffraction grating, a microlens array, a diffusant-containing resin film containing a diffusant and a resin, etc. can be listed. Specifically, in the case where the first layer has a light diffusivity that mainly diffuses light in a specific direction, a transmission type diffraction grating and a microlens array can be cited. On the other hand, in the case where the first layer has a light diffusivity that randomly diffuses light, a diffusant-containing resin film can be cited. Among them, from the viewpoint of light diffusivity, a transmission type diffraction grating and a microlens array are preferred. In addition, a transmission type diffraction grating is also referred to as a transmission type diffractive optical element (DOE; Diffractive Optical Elements).

[0088] When the first layer is a transmission type diffraction grating, the transmission type diffraction grating is not particularly limited as long as it has the above-mentioned light transmittance and light diffraction properties.

[0089] As a transmission type diffraction grating, for example, it can be any of a phase type diffraction grating and an amplitude type diffraction grating. In addition, the phase type diffraction grating can be any of a relief type diffraction grating and a volume type diffraction grating. Among them, the transmission type diffraction grating is preferably a relief type diffraction grating. Furthermore, in the case where the transmission type diffraction grating is a relief type diffraction grating, it is preferably a multi-order diffraction grating in which the cross-sectional shape of the groove has a stepped shape. Generally speaking, for a multi-order diffraction grating, the spacing of the diffraction grating is small, and therefore, it is particularly effective for the present disclosure that does not require the alignment of the diffusion component and the LED element. In the multi-order diffraction grating, the number of levels can be set to, for example, 2 levels, 4 levels, 8 levels, 16 levels, etc. Figure 6 This is an example of a multi-order diffraction grating 2a having four orders.

[0090] In addition, as the transmission type diffraction grating, for example, a transmission type diffraction grating that diffracts transmission light and emits light with a non-Gaussian intensity distribution can be listed. Specifically, a transmission type diffraction grating that diffracts transmission light and emits light with a ring-shaped intensity distribution and a transmission type diffraction grating that diffracts transmission light and emits light with a top-hat-shaped intensity distribution can be listed. Among them, the transmission type diffraction grating is preferably a transmission type diffraction grating that diffracts transmission light and emits light with a ring-shaped intensity distribution, that is, it is preferably a transmission type diffraction grating that diffracts transmission light and emits transmission diffraction light with a ring-shaped intensity distribution in which the intensity of the transmission diffraction light emitted at the peripheral portion is stronger than the intensity of the transmission diffraction light emitted at the center of the optical axis. It is particularly preferred to emit transmission diffraction light with a ring-shaped intensity distribution (for example, Figure 4 A transmission type diffraction grating in which the intensity of the transmitted diffracted light emitted at the center of the optical axis is substantially zero as shown in (a). In the case of such a transmission type diffraction grating, when the diffusion component of the present invention is used for an LED backlight, the intensity of the light emitted at the center of the optical axis can be reduced, and the intensity of the light emitted at the peripheral portion can be increased, thereby further improving the in-plane uniformity of the brightness.

[0091] In the case of a transmission-type diffraction grating that diffracts light and emits light having an annular intensity distribution, in the annular intensity distribution, the angle formed by the direction in which the intensity of the transmitted diffracted light is the largest and the normal direction of the transmission-type diffraction grating can be set to, for example, 30° or more and 75° or less. If the above angle is too small, the effect of expanding the light in the lateral direction cannot be fully obtained, and it may become difficult to make the brightness uniform. In addition, if the above angle is too large, it may cause total reflection, making it difficult to make the brightness uniform. In addition, the above angle can be, for example, 30° or more and 45° or less. When the above angle is within the above range, it is relatively easy to make the transmission-type diffraction grating.

[0092] Here, the intensity distribution and the angle can be measured using a goniophotometer or a goniospectrocolorimeter. For example, a goniophotometer (goniometer) GP-200 or a goniospectrocolorimeter GCMS-11 manufactured by Murakami Color Research Laboratory can be used to measure the angle.

[0093] The pitch of the transmission type diffraction grating can be appropriately adjusted as long as the above-mentioned light transmittance and light diffusivity can be obtained. Specifically, when the wavelength output by the LED element is a single color such as red, green, or blue, by setting the pitch to correspond to each wavelength, the light from the LED element can be effectively bent.

[0094] Specifically, the pitch of the transmission diffraction grating may be set to 50 μm or more and 200 μm or less. As described above, the diffusion member of the present disclosure does not need to be aligned with the LED element, and is therefore particularly effective when the pitch of the transmission diffraction grating is as small as in the above range.

[0095] Furthermore, when the transmission-type diffraction grating is a relief-type diffraction grating, the depth of the grooves of the transmission-type diffraction grating can be set to, for example, 1 μm or more and 5 μm or less.

[0096] The pitch of a transmission type diffraction grating, for example, in the case of a multi-order diffraction grating, refers to Figure 6 The distance P between adjacent grooves is as shown in FIG. 1 . The depth of the grooves of a transmission type diffraction grating, for example, in the case of a multi-order diffraction grating, refers to Figure 6 The maximum depth d1 of the groove is shown.

[0097] Here, the pitch and groove depth of the transmission diffraction grating can be obtained from a top-view microscope photograph of the transmission diffraction grating observed through a transmission electron microscope (TEM), a scanning electron microscope (SEM) or a scanning transmission electron microscope (STEM) or a cross-sectional microscope photograph of the transmission diffraction grating in the thickness direction.

[0098] As a material constituting the transmission type diffraction grating, any material that can obtain a transmission type diffraction grating having the above-mentioned light transmittance and light diffraction property can be used, and materials commonly used for transmission type diffraction gratings can be used, for example, glass such as quartz glass, resin, etc.

[0099] In addition, the method for forming a transmission-type diffraction grating may be the same as the method for forming a general transmission-type diffraction grating. In the case where the transmission-type diffraction grating is a multi-order diffraction grating, as the method for forming the transmission-type diffraction grating, for example, a method for processing a glass substrate such as a quartz substrate by photolithography using a direct drawing method of an electron beam or a laser, or photolithography using a photomask, can be cited. By repeatedly performing a photolithography process and an etching process, a groove having a step shape can be formed on the glass substrate. In addition, as other methods for forming a transmission-type diffraction grating, resin shaping based on a mold can be cited. In this case, for example, a resin layer can be formed on one surface of a substrate layer, and the resin layer can be shaped using a mold, thereby forming a groove having a step shape on the resin layer. A resin layer can also be formed on one surface of a second layer, and the resin layer can be shaped using a mold, thereby forming a groove having a step shape on the resin layer. As a method for manufacturing a mold, the following method can be cited: first, a glass substrate such as a quartz substrate is processed by the above-mentioned photolithography using a direct drawing method of an electron beam or a laser, or photolithography using a photomask, and a molding mold is produced by this method, and then a reverse mold is produced using the molding mold, and the reverse mold can be used as a mold. In addition, as a design method of a transmission type diffraction grating, for example, an iterative Fourier transform algorithm (IFTA) can be used.

[0100] When the first layer is a microlens array, the microlens array is not particularly limited as long as it has the above-mentioned light transmittance and light diffusibility.

[0101] In addition, as a microlens array, for example, a microlens array that transmits and refracts light and emits light with a non-Gaussian intensity distribution can be listed. Specifically, a microlens array that transmits and refracts light and emits light with an annular intensity distribution and a microlens array that transmits and refracts light and emits light with a top-hat-shaped intensity distribution can be listed. Among them, the microlens is preferably a microlens array that transmits and refracts light and emits light with an annular intensity distribution, that is, it is preferably a microlens array that transmits and refracts light and emits transmitted and refracted light with an annular intensity distribution in which the intensity of the transmitted and refracted light emitted at the center of the optical axis is stronger than the intensity of the transmitted and refracted light emitted at the peripheral portion. In the case of such a microlens array, when the diffusion component of the present disclosure is used for an LED backlight source, the intensity of the light emitted at the center of the optical axis can be reduced, and the intensity of the light emitted at the peripheral portion can be increased, so that the in-plane uniformity of the brightness can be further improved.

[0102] The shape, pitch, size, etc. of the microlenses may be appropriately adjusted as long as the above-mentioned light transmittance and light diffusibility can be obtained.

[0103] Specifically, the spacing of the microlenses in the microlens array can be set to be less than 1 mm, or less than 0.6 mm. As described above, the diffusion component of the present disclosure does not need to be aligned with the LED element, and is therefore particularly effective when the spacing of the microlenses is as small as in the above range. In addition, the spacing of the microlenses can be set to be greater than 0.001 mm, for example.

[0104] Here, the pitch of the microlenses can be obtained from a top-view micrograph of the microlens array or a cross-sectional micrograph of the microlens array in the thickness direction observed by a transmission electron microscope (TEM), a scanning electron microscope (SEM), or a scanning transmission electron microscope (STEM).

[0105] As a material constituting the microlens, any material that can obtain a microlens having the above-mentioned light transmittance and light diffusibility can be used, and a material commonly used for a microlens can be used. In addition, as a method for forming the microlens, it can be the same as a general method for forming a microlens.

[0106] When the first layer is a diffusing agent-containing resin film, the diffusing agent-containing resin film is not particularly limited as long as it has the above-mentioned light transmittance and light diffusibility.

[0107] The diffusing agent contained in the diffusing agent-containing resin film is not particularly limited as long as it can diffuse the light from the LED element, and the diffusing agent commonly used in the diffusing plate for LED backlight can be adopted. The content of the diffusing agent in the diffusing agent-containing resin film is not particularly limited as long as it can diffuse the light from the LED element, and the content can be the same as that of the diffusing agent commonly used in the diffusing plate for LED backlight.

[0108] The resin contained in the diffusing agent-containing resin film is not particularly limited as long as it can disperse the diffusing agent, and a resin generally used in a diffusing plate for an LED backlight can be used.

[0109] The first layer may have a structure capable of exhibiting light diffusivity, for example, it may be a layer exhibiting light diffusivity in the entire layer or a layer exhibiting light diffusivity on the surface. As a layer exhibiting light diffusivity on the surface, for example, a relief type diffraction grating and a microlens array may be cited. On the other hand, as a layer exhibiting light diffusivity in the entire layer, for example, a volume type diffraction grating and a diffusing agent-containing resin film may be cited.

[0110] Regarding the configuration of the first layer and the second layer, for example, the first layer may be directly configured on one surface of the second layer, or the first layer may be configured on one surface of the second layer via an adhesive layer or a bonding layer, or Figure 7 The first layer 2 is arranged on one surface of the second layer 3 with a gap therebetween as shown in (a). For example, when the first layer is a layer that exhibits light diffusivity on the surface, and when the first layer has a structure that can exhibit light diffusivity on the surface opposite to the second layer, it is preferred that the first layer and the second layer be arranged with a gap therebetween. In addition, when the first layer is directly arranged on one surface of the second layer, for example, Figure 7 As shown in (b), the first layer 2 may be arranged in a pattern on one surface of the second layer 3. For example, when the first layer is a layer that exhibits light diffusivity on the surface, the light diffusivity can be exhibited even when the first layer is arranged in a pattern.

[0111] When the first layer and the second layer are arranged with a gap therebetween, the first layer and the second layer may or may not be in contact. When the first layer and the second layer are not in contact, for example, a spacer may be arranged between the first layer and the second layer. In addition, the gap may be an air layer.

[0112] As a method for laminating the first layer and the second layer, for example, there can be cited a method of laminating the first layer and the second layer via an adhesive layer or a bonding layer, a method of directly forming the first layer on one surface of the second layer, etc. As a method for directly forming the first layer on one surface of the second layer, for example, there can be cited a printing method, resin shaping by a mold, etc. In the case of the printing method or the resin shaping by a mold, the patterned first layer can be directly formed on one surface of the second layer.

[0113] 2. Layer 2

[0114] The second layer disclosed in the present invention is arranged on one side of the above-mentioned first layer, and is a component having the following characteristics: the incident angle dependence of the reflectivity, such that the reflectivity increases as the absolute value of the incident angle of light relative to the surface of the above-mentioned second layer on the side of the above-mentioned first layer decreases; and the incident angle dependence of the transmittance, such that the transmittance increases as the absolute value of the incident angle of light relative to the surface of the above-mentioned second layer on the side of the above-mentioned first layer increases.

[0115] The second layer has a reflectivity dependency of the angle of incidence such that the reflectivity increases as the absolute value of the incident angle of light relative to the surface of the second layer on the first layer side decreases. That is, the reflectivity of light incident at a low incident angle relative to the surface of the second layer on the first layer side is greater than the reflectivity of light incident at a high incident angle relative to the surface of the second layer on the first layer side. Preferably, the reflectivity of light incident at a low incident angle relative to the surface of the second layer on the first layer side is greater.

[0116] Specifically, the regular reflectivity of visible light incident at an incident angle within ±60° relative to the surface of the second layer on the side of the first layer is preferably 50% or more and less than 100%, preferably 80% or more and less than 100%, and particularly preferably 90% or more and less than 100%. It should be noted that preferably, at all incident angles within ±60°, the regular reflectivity of visible light satisfies the above range. By setting the above regular reflectivity to the above range, when the diffusion component disclosed in the present invention is used for an LED backlight source, the in-plane uniformity of the brightness can be improved.

[0117] In addition, the average value of the regular reflectivity of visible light incident at an incident angle within ±60° relative to the surface of the second layer on the side of the first layer is preferably, for example, 80% or more and 99% or less, preferably 90% or more and 97% or less. It should be noted that the average value of the regular reflectivity refers to the average value of the regular reflectivity of visible light at each incident angle. By making the average value of the regular reflectivity within the above range, when the diffusion component disclosed in the present invention is used for an LED backlight source, the in-plane uniformity of the brightness can be improved.

[0118] In addition, the regular reflectivity of visible light incident at an incident angle of 0° (vertical incidence) with respect to the surface of the second layer on the side of the first layer is preferably, for example, 80% or more and less than 100%, preferably 90% or more and less than 100%, and particularly preferably 95% or more and less than 100%. By making the regular reflectivity within the above range, when the diffusion component of the present disclosure is used for an LED backlight, the in-plane uniformity of brightness can be improved.

[0119] It should be noted that, in this specification, "visible light" refers to light with a wavelength of more than 380nm and a wavelength of less than 780nm. In addition, the regular reflectivity can be measured using a goniophotometer or a goniospectrocolorimeter. In the measurement of regular reflectivity, for example, a goniophotometer (goniometer) GP-200, a goniospectrocolorimeter GCMS-11, etc. made by Murakami Color Technology Research Institute, Inc. can be used.

[0120] In addition, the total light transmittance of light incident at an incident angle within ±60° relative to the surface of the second layer on the side of the first layer is preferably, for example, 10% or less, preferably 5% or less, and particularly preferably 3% or less. It should be noted that it is preferred that the total light transmittance satisfies the above range at all incident angles within ±60°. If the above total light transmittance is within the above range, the above regular reflectance can be set within a specified range, and when the diffusion component disclosed in the present invention is used for an LED backlight source, the in-plane uniformity of the brightness can be improved.

[0121] The second layer has an incident angle dependence of transmittance such that the transmittance increases as the absolute value of the incident angle of light relative to the surface of the second layer on the side of the first layer increases. That is, the transmittance of light incident at a high incident angle relative to the surface of the second layer on the side of the first layer is greater than the transmittance of light incident at a low incident angle relative to the surface of the second layer on the side of the first layer. Among them, it is preferred that the transmittance of light incident at a high incident angle relative to the surface of the second layer on the side of the first layer is larger. Specifically, the total transmittance of light incident at an incident angle of more than 70° and less than 90° relative to the surface of the second layer on the side of the first layer is preferably more than 30%, preferably more than 40%, and particularly preferably more than 50%. It should be noted that it is preferred that the total transmittance satisfies the above range at all incident angles of more than 70° and less than 90°. In addition, it is preferred that the total transmittance satisfies the above range when the absolute value of the incident angle is more than 70° and less than 90°. By setting the total light transmittance to the above range, when the diffusion member of the present disclosure is used for an LED backlight, the in-plane uniformity of brightness can be improved.

[0122] It should be noted that the total light transmittance of the second layer can be measured, for example, using a goniophotometer or a goniospectrocolorimeter according to JIS K7361-1: 1997. In the measurement of the total light transmittance, for example, a UV-visible-near-infrared spectrophotometer V-7200 manufactured by JASCO Corporation can be used. As a light source, a CIE standard light source D65 can be used.

[0123] In addition, the regular reflectivity of visible light incident on the surface of the second layer on the first layer side at an incident angle of not less than 70° and not more than 90° is preferably, for example, not more than 70%, preferably not more than 60%, and particularly preferably not more than 50%. It should be noted that, preferably, at all incident angles not less than 70° and not more than 90°, the regular reflectivity of visible light satisfies the above range. In addition, preferably, when the absolute value of the incident angle is not less than 70° and not more than 90°, the regular reflectivity of visible light satisfies the above range. If the above regular reflectivity is within the above range, the above total light transmittance can be within the specified range, so that when the diffusion component disclosed in the present invention is used for an LED backlight source, the in-plane uniformity of the brightness can be improved.

[0124] In addition, the average value of the regular reflectivity of visible light incident at an incident angle of more than 70° and less than 90° relative to the surface of the second layer on the side of the first layer is preferably, for example, less than 70%, preferably less than 50%, and particularly preferably less than 30%. It should be noted that the average value of the regular reflectivity refers to the average value of the regular reflectivity of visible light at each incident angle. If the average value of the regular reflectivity is within the above range, the total light transmittance can be within the specified range, thereby, when the diffusion component disclosed in the present invention is used for an LED backlight source, the in-plane uniformity of the brightness can be improved.

[0125] The second layer is not particularly limited as long as it has the above-mentioned incident angle dependence of reflectivity and transmittance, and various structures having the above-mentioned incident angle dependence of reflectivity and transmittance can be adopted. As the second layer, for example, there can be mentioned: a dielectric multilayer film; a reflective structure having a patterned first reflective film and a patterned second reflective film in order from the first layer side, the opening of the first reflective film and the opening of the second reflective film being positioned so as not to overlap when viewed from above, and the first reflective film and the second reflective film being arranged separately in the thickness direction; and a reflective diffraction grating, etc.

[0126] Hereinafter, a case where the second layer is a dielectric multilayer film, a reflective structure, or a reflective diffraction grating will be described.

[0127] (1) Dielectric multilayer film

[0128] When the second layer is a dielectric multilayer film, examples of the dielectric multilayer film include an inorganic compound multilayer film in which inorganic layers having different refractive indices are alternately laminated, and a resin multilayer film in which resin layers having different refractive indices are alternately laminated.

[0129] (Multilayer films of inorganic compounds)

[0130] When the dielectric multilayer film is an inorganic compound multilayer film in which inorganic layers having different refractive indices are alternately stacked, the inorganic compound multilayer film is not particularly limited as long as it has the above-mentioned incident angle dependence of reflectivity and transmittance.

[0131] As the inorganic compound contained in the high refractive index inorganic layer with a high refractive index among the inorganic layers with different refractive indices, for example, the refractive index can be set to be 1.7 or more, or 1.7 or more and 2.5 or less. As such inorganic compounds, for example, inorganic compounds with titanium oxide, zirconium oxide, tantalum pentoxide, niobium pentoxide, lanthanum oxide, yttrium oxide, zinc oxide, zinc sulfide, indium oxide as main components and containing a small amount of titanium oxide, tin oxide, cerium oxide, etc. can be listed.

[0132] In addition, as the inorganic compound contained in the low refractive index inorganic layer with low refractive index in the inorganic layer with different refractive index, for example, the refractive index can be set to below 1.6, or can be above 1.2 and below 1.6. As such inorganic compound, for example, silicon dioxide, aluminum oxide, lanthanum fluoride, magnesium fluoride, sodium aluminum hexafluoride, etc. can be listed.

[0133] About the lamination number of high refractive index inorganic layer and low refractive index inorganic layer, as long as can obtain the incident angle dependence of above-mentioned reflectivity and transmittance, can suitably adjust.Specifically, the total lamination number of high refractive index inorganic layer and low refractive index inorganic layer can be set as more than 4 layers.In addition, as the upper limit of above-mentioned total lamination number, be not particularly limited, but the more lamination number then operation increases more, therefore for example can be set as below 24 layers.

[0134] The thickness of the multilayer film of the inorganic compound may be any thickness as long as the above-mentioned incidence angle dependence of the reflectance and the transmittance can be obtained, and can be, for example, 0.5 μm or more and 10 μm or less.

[0135] Examples of a method for forming a multilayer film of an inorganic compound include a method of alternately laminating a high-refractive-index inorganic layer and a low-refractive-index inorganic layer by CVD, sputtering, vacuum deposition, wet coating, or the like.

[0136] (Multilayer film of resin)

[0137] When the dielectric multilayer film is a resin multilayer film in which resin layers having different refractive indices are alternately laminated, the resin multilayer film is not particularly limited as long as it has the above-mentioned incident angle dependence of reflectivity and transmittance.

[0138] Examples of the resin constituting the resin layer include thermoplastic resins and thermosetting resins, of which thermoplastic resins are preferred because of their good moldability.

[0139] Various additives may be added to the resin layer, such as antioxidants, antistatic agents, crystal nucleating agents, inorganic particles, organic particles, viscosity reducing agents, heat stabilizers, lubricants, infrared absorbers, ultraviolet absorbers, dopants for adjusting the refractive index, and the like.

[0140] As the thermoplastic resin, for example, polyolefin resins such as polyethylene, polypropylene, polystyrene, and polymethylpentene, alicyclic polyolefin resins, polyamide resins such as nylon 6 and nylon 66, aromatic polyamide resins, polyester resins such as polyethylene terephthalate, polybutylene terephthalate, polypropylene terephthalate, polybutylene succinate, and polyethylene 2,6-naphthalate, polycarbonate resins, polyarylate resins, polyacetal resins, polyphenylene sulfide resins, 4-fluorinated ethylene resins, 3-fluorinated ethylene resins, 3-fluorinated vinyl chloride resins, 4-fluorinated ethylene-6-fluorinated propylene copolymers, and fluorinated resins such as vinylidene fluoride resins, acrylic resins, methacrylic resins, polyacetal resins, polyglycolic acid resins, and polylactic acid resins can be used. Among them, polyester is more preferred from the viewpoints of strength, heat resistance, and transparency.

[0141] In this specification, polyester refers to a homopolyester or copolyester which is a condensation product of a dicarboxylic acid component skeleton and a diol component skeleton. Here, as the homopolyester, for example, polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, polyethylene 2,6-naphthalate, and polyethylene 1,4-cyclohexane terephthalate can be cited. Among them, polyethylene terephthalate is preferred because it is inexpensive and can be used in a wide range of applications.

[0142] In addition, in this specification, copolyester is defined as a polycondensate composed of at least three components selected from the following components having a dicarboxylic acid skeleton and components having a diol skeleton. As the component having a dicarboxylic acid skeleton, for example, terephthalic acid, isophthalic acid, phthalic acid, 1,4-naphthalene dicarboxylic acid, 1,5-naphthalene dicarboxylic acid, 2,6-naphthalene dicarboxylic acid, 4,4-diphenyl dicarboxylic acid, 4,4-diphenyl sulfone dicarboxylic acid, adipic acid, sebacic acid, dimer acid, cyclohexane dicarboxylic acid and their ester derivatives can be listed. As the component having a diol skeleton, for example, ethylene glycol, 1,2-propylene glycol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, diethylene glycol, polyalkylene glycol, 2,2-bis(4-β-hydroxyethoxyphenyl)propane, isosorbide, 1,4-cyclohexanedimethanol, spiroglycol and the like can be listed.

[0143] The difference in the average refractive index between the high refractive index resin layer with a high refractive index and the low refractive index resin layer with a low refractive index in the resin layers with different refractive indices is preferably 0.03 or more, more preferably 0.05 or more, and further preferably 0.1 or more. When the difference in the average refractive index in the above plane is too small, sufficient reflectivity may not be obtained.

[0144] In addition, the difference between the in-plane average refractive index of the high refractive index resin layer and the refractive index in the thickness direction is preferably 0.03 or more, and the difference between the in-plane average refractive index of the low refractive index resin layer and the refractive index in the thickness direction is preferably 0.03 or less. In this case, even if the incident angle increases, it is not easy to cause a reduction in the reflectivity of the reflection peak.

[0145] As a preferred combination of a high refractive index resin used in the high refractive index resin layer and a low refractive index resin used in the low refractive index resin layer, first, the absolute value of the difference in SP values ​​between the high refractive index resin and the low refractive index resin is preferably less than 1.0. When the absolute value of the difference in SP values ​​is within the above range, it is difficult to produce interlayer peeling. In this case, it is more preferred that the high refractive index resin and the low refractive index resin contain the same basic skeleton. Here, the basic skeleton refers to the repeating units that constitute the resin. For example, in the case where one side of the resin is polyethylene terephthalate, ethylene terephthalate is the basic skeleton. In addition, for example, in the case where one side of the resin is polyethylene, ethylene is the basic skeleton. If the high refractive index resin and the low refractive index resin are resins containing the same basic skeleton, it is less likely to produce interlayer peeling.

[0146] As a preferred combination of the high refractive index resin used in the high refractive index resin layer and the low refractive index resin used in the low refractive index resin layer, secondly, the difference in glass transition temperature between the high refractive index resin and the low refractive index resin is preferably 20°C or less. If the difference in glass transition temperature is too large, the thickness uniformity when manufacturing the laminated film of the high refractive index resin layer and the low refractive index resin layer may sometimes become poor. In addition, when forming the above-mentioned laminated film, overstretching may sometimes occur.

[0147] In addition, it is preferred that the high refractive index resin is polyethylene terephthalate or polyethylene naphthalate, and the low refractive index resin is a polyester containing spiroglycol. Here, the polyester containing spiroglycol refers to a copolyester formed by copolymerizing spiroglycol, or a homopolyester, or a polyester formed by mixing them. The difference between the glass transition temperature of the polyester containing spiroglycol and polyethylene terephthalate and polyethylene naphthalate is small, so it is not easy to over-stretch during molding, and it is also not easy to peel between layers, so it is preferred. It is more preferred that the high refractive index resin is polyethylene terephthalate or polyethylene naphthalate, and the low refractive index resin is a polyester containing spiroglycol and cyclohexane dicarboxylic acid. When the low refractive index resin is a polyester containing spiroglycol and cyclohexane dicarboxylic acid, the difference between the in-plane refractive index of the polyester containing spiroglycol and polyethylene terephthalate or polyethylene naphthalate becomes large, so it is easy to obtain high reflectivity. In addition, since the difference in glass transition temperature between polyethylene terephthalate and polyethylene naphthalate is small and the adhesiveness is excellent, it is unlikely to be excessively stretched during molding and interlayer delamination is unlikely to occur.

[0148] In addition, it is also preferred that the high refractive index resin is polyethylene terephthalate or polyethylene naphthalate, and the low refractive index resin is a polyester containing cyclohexanedimethanol. Here, the polyester containing cyclohexanedimethanol refers to a copolyester formed by copolymerizing cyclohexanedimethanol, or a homopolyester, or a polyester formed by mixing them. Regarding the polyester containing cyclohexanedimethanol, since the difference between the glass transition temperature of the polyester and polyethylene terephthalate or polyethylene naphthalate is small, it is not easy to over-stretch during molding, and it is not easy to peel between layers, so it is preferred. In this case, the low refractive index resin is more preferably a condensation product of polyethylene terephthalate in which the copolymerization amount of cyclohexanedimethanol is more than 15 mol% and less than 60 mol%. As a result, it has high reflective performance, and, in particular, the change in optical properties caused by heating and time is small, and it is not easy to peel between layers. The ethylene terephthalate polycondensate having a copolymerization amount of cyclohexanedimethanol within the above range is very strongly bonded to polyethylene terephthalate. In addition, the cyclohexanedimethanol group has a cis-isomer or a trans-isomer as a geometric isomer, and also has a chair type or a boat type as a conformational isomer. Therefore, even if co-stretched with polyethylene terephthalate, it is difficult to orient and crystallize, and has a high reflectivity, and the change in optical properties caused by the thermal history is less, and it is difficult to cause cracks during film formation.

[0149] In the above-mentioned multilayer film of resin, as long as there is a part of the structure in which the high refractive index resin layer and the low refractive index resin layer are alternately stacked in the thickness direction. That is, it is preferred that the sequence of the configuration of the high refractive index resin layer and the low refractive index resin layer in the thickness direction is not a random state, and the sequence of the configuration of the resin layer other than the high refractive index resin layer and the low refractive index resin layer is not particularly limited. In addition, in the case where the above-mentioned multilayer film of resin has a high refractive index resin layer, a low refractive index resin layer and other resin layers, as the order of their configuration, when the high refractive index resin layer is set to A, the low refractive index resin layer is set to B, and the other resin layers are set to C, it is more preferred to stack each layer in a regular order such as A(BCA)n, A(BCBA)n, A(BABCBA)n. Here, n is the number of repeated units, for example, in the case of n=3 in A(BCA)n, it means that it is stacked in the order of ABCABCABCA in the thickness direction.

[0150] In addition, about the lamination number of high refractive index resin layer and low refractive index resin layer, as long as the incident angle dependence of above-mentioned reflectivity and transmittance can be obtained, it can be appropriately adjusted. Specifically, high refractive index resin layer and low refractive index resin layer can be alternately laminated more than 30 layers respectively, and can also be laminated more than 200 layers respectively. In addition, the total lamination number of high refractive index resin layer and low refractive index resin layer can be set to more than 600 layers, for example. When the lamination number is too few, sufficient reflectivity can not be obtained sometimes. In addition, by making the lamination number be the above-mentioned range, desired reflectivity can be easily obtained. In addition, as the upper limit of the above-mentioned total lamination number, it is not particularly limited. If the reduction of the lamination precision caused by considering the large-scale of the device and the excessive number of layers is considered, then for example, it can be set to less than 1500 layers.

[0151] Furthermore, the above-mentioned multilayer film of resin preferably has a surface layer on at least one side, and the surface layer contains polyethylene terephthalate or polyethylene naphthalate with a thickness of 3 μm or more, wherein the above-mentioned surface layer is preferably provided on both sides. In addition, the thickness of the surface layer is more preferably 5 μm or more. By having the above-mentioned surface layer, the surface of the above-mentioned multilayer film of resin can be protected.

[0152] Examples of the method for producing the above-mentioned multilayer film of the resin include a coextrusion method, etc. Specifically, the method for producing a laminated film described in Japanese Unexamined Patent Application Publication No. 2008-200861 can be referred to.

[0153] As the multilayer film of the above resin, a commercially available laminated film can be used, and specific examples thereof include PICASUS (registered trademark) manufactured by Toray Industries, Inc. and ESR manufactured by 3M Company.

[0154] (2) Reflective structure

[0155] The reflective structure has a patterned first reflective film and a patterned second reflective film in sequence from the first layer side, the opening of the first reflective film and the opening of the second reflective film are positioned so as not to overlap when viewed from above, and the first reflective film and the second reflective film are arranged separately in the thickness direction.

[0156] There are two modes of the reflective structure. The first mode of the reflective structure comprises: a transparent substrate; a patterned first reflective film, which is arranged on one surface of the transparent substrate; and a patterned second reflective film, which is arranged on the other surface of the transparent substrate, the opening of the first reflective film and the opening of the second reflective film are positioned in a manner that they do not overlap when viewed from above, and the first reflective film and the second reflective film are separately arranged in the thickness direction. In addition, the second mode of the reflective structure comprises: a transparent substrate; a patterned convex portion with light transmittance, which is arranged on one surface of the transparent substrate; a patterned first reflective film, which is arranged on the side of the convex portion opposite to the side of the transparent substrate; and a patterned second reflective film, which is arranged on the opening of the convex portion on one surface of the transparent substrate, the opening of the first reflective film and the opening of the second reflective film are positioned in a manner that they do not overlap when viewed from above, and the first reflective film and the second reflective film are separately arranged in the thickness direction. The following is a description of each mode.

[0157] (First embodiment of the reflective structure)

[0158] The first embodiment of the reflective structure disclosed in the present invention comprises: a transparent substrate; a patterned first reflective film disposed on one surface of the transparent substrate; and a patterned second reflective film disposed on the other surface of the transparent substrate, wherein the opening of the first reflective film and the opening of the second reflective film are positioned so as not to overlap when viewed from above, and the first reflective film and the second reflective film are disposed separately in the thickness direction. In the case of the reflective structure of this embodiment, in the diffuser of the present invention, the first layer is disposed on the surface side of the reflective structure on the first reflective film side.

[0159] Figure 8 (a) and (b) are a schematic plan view and a cross-sectional view showing an example of a reflective structure of the present embodiment. Figure 8 (a) is a top view of the reflective structure as viewed from the first reflective film side. Figure 8 (b) is Figure 8 (a) AA line cross-sectional view. Figure 8 As shown in (a) and (b) of FIG. 1 , the reflective structure 20 includes a transparent substrate 21, a patterned first reflective film 22 disposed on one surface of the transparent substrate 21, and a second reflective film 24 disposed on the other surface of the transparent substrate 21. The opening 23 of the first reflective film 22 and the opening 25 of the second reflective film 24 are positioned so as not to overlap when viewed from above. In addition, the first reflective film 22 and the second reflective film 24 are disposed on both surfaces of the transparent substrate 21, respectively, and are separated in the thickness direction. In addition, Figure 8 In (a), the opening of the second reflective film is indicated by a dotted line. Figure 8 (c) is a schematic cross-sectional view showing an example of an LED backlight including a diffusion member having a reflective structure according to this embodiment.

[0160] In such a reflective structure, since the patterned first reflective film and the second reflective film are stacked, and the opening of the first reflective film and the opening of the second reflective film are positioned so as not to overlap when viewed from above, when the diffusion component having the reflective structure of this embodiment is used for an LED backlight, for example, Figure 8 As shown in (c), at least one of the first reflective film 22 and the second reflective film 24 must exist directly above the LED element 13. Therefore, for example, Figure 8 As shown in (b), the light L11 incident at a low incident angle with respect to the surface on the first reflective film 22 side of the reflective structure 20, that is, the surface 3A on the side where the first layer (not shown) of the reflective structure 20 (second layer) is arranged can be reflected by the first reflective film 22 and the second reflective film 24. In addition, since the opening of the first reflective film and the opening of the second reflective film are positioned so as not to overlap when viewed from above, and the first reflective film and the second reflective film are arranged separately in the thickness direction, the light L12 and L13 incident at a high incident angle with respect to the surface on the first reflective film 22 side of the reflective structure 20, that is, the surface 3A on the side where the first layer (not shown) of the reflective structure 20 (second layer) is arranged can be emitted from the opening 23 of the first reflective film 22 and the opening 25 of the second reflective film 24. Thus, part of the light emitted from the LED element and then emitted from the second layer side surface of the diffusion member can be emitted from a position away from the LED element in the in-plane direction, rather than being emitted from directly above the LED element. Therefore, the in-plane uniformity of brightness can be improved.

[0161] Hereinafter, the reflective structure of this embodiment will be described.

[0162] As the first reflective film and the second reflective film, general reflective films can be used, for example, metal films, dielectric multilayer films, etc. can be used. As the material of the metal film, metal materials used in general reflective films can be used, for example, aluminum, gold, silver, and their alloys can be listed. In addition, as the dielectric multilayer film, dielectric multilayer films used in general reflective films can be used, for example, multilayer films of inorganic compounds such as multilayer films formed by alternately stacking zirconium oxide and silicon oxide can be listed. The materials contained in the first reflective film and the second reflective film can be the same or different from each other.

[0163] The pitch of the openings of the first reflective film and the second reflective film may be set appropriately as long as the above-mentioned incident angle dependence of the reflectivity and the transmittance can be obtained, depending on the light distribution characteristics, size, pitch and shape of the LED elements in the LED backlight using the diffusion component of the present invention, the distance between the LED substrate and the diffusion component, etc. The pitch of the openings of the first reflective film and the second reflective film may be the same or different from each other.

[0164] The pitch of the openings of the first reflection film may be larger than the size of the LED element, for example. Specifically, the pitch of the openings of the first reflection film may be set to 0.1 mm or more and 20 mm or less.

[0165] In addition, the pitch of the openings of the second reflective film is not particularly limited as long as it can suppress uneven brightness, and is preferably less than the pitch of the openings of the first reflective film, and preferably smaller than the pitch of the openings of the first reflective film. Specifically, the pitch of the openings of the second reflective film can be set to be greater than 0.1 mm and less than 2 mm. By making the pitch of the openings of the second reflective film fine as described above, the pattern of the part of the second reflective film and the part of the opening of the second reflective film can be made difficult to visually recognize, thereby achieving surface light emission without unevenness.

[0166] The pitch of the openings of the first reflective film refers to, for example, Figure 8 The distance P1 between the centers of the openings 23 of the adjacent first reflective films 22 as shown in (a) of FIG. 2 is the distance P2 between the centers of the openings 23 of the adjacent first reflective films 22. The pitch of the openings of the second reflective film is, for example, Figure 8 As shown in (a), the distance P2 between the centers of the openings 25 of the adjacent second reflection films 24 is .

[0167] The sizes of the openings of the first reflective film and the second reflective film may be set appropriately as long as the above-mentioned incident angle dependence of the reflectivity and the transmittance can be obtained, depending on the light distribution characteristics, size, pitch and shape of the LED elements in the LED backlight using the diffusion component of the present invention, the distance between the LED substrate and the diffusion component, etc. The sizes of the openings of the first reflective film and the second reflective film may be the same or different from each other.

[0168] As the size of the opening of the first reflection film, specifically, when the shape of the opening of the first reflection film is a rectangle, the length of the opening of the first reflection film can be set to 0.1 mm or more and 5 mm or less.

[0169] In addition, the size of the opening of the second reflective film is not particularly limited as long as it can suppress uneven brightness, and is preferably smaller than the size of the opening of the first reflective film, and preferably smaller than the size of the opening of the first reflective film. Specifically, when the shape of the opening of the second reflective film is rectangular, the length of the opening of the second reflective film can be greater than 0.05 mm and less than 2 mm. By making the size of the opening of the second reflective film fine as described above, the pattern of the part of the second reflective film and the part of the opening of the second reflective film can be made difficult to visually recognize, thereby achieving surface light emission without unevenness.

[0170] In addition, the size of the opening of the first reflection film, for example, when the shape of the opening of the first reflection film is a rectangular shape, refers to the following: Figure 8 The length x1 of the opening 23 of the first reflective film 22 shown in (a) is shown in FIG. 1. The size of the opening of the second reflective film is, for example, Figure 8 The length x2 of the opening 25 of the second reflective film 24 shown in (a) is .

[0171] The shapes of the openings of the first reflection film and the second reflection film may be any shapes, such as a rectangular shape or a circular shape.

[0172] The thickness of the first reflective film and the second reflective film may be appropriately adjusted as long as the above-mentioned incident angle dependence of the reflectance and transmittance can be obtained. Specifically, the thickness of the first reflective film and the second reflective film may be set to 0.05 μm or more and 100 μm or less.

[0173] The first reflective film and the second reflective film may be formed on the surface of a transparent substrate, or may be a sheet-like reflective film. The method for forming the first reflective film and the second reflective film is not particularly limited as long as it is a method that can form a reflective film in a pattern on the surface of a transparent substrate, and for example, sputtering, vacuum evaporation, etc. may be cited. In addition, in the case where the first reflective film and the second reflective film are sheet-like reflective films, as a method for forming the opening portion, for example, a method for forming a plurality of through holes by punching, etc. may be cited. In this case, as a lamination method of the transparent substrate and the sheet-like reflective film, for example, a method of laminating a sheet-like reflective film on a transparent substrate via an adhesive layer or a bonding layer may be used.

[0174] The transparent substrate in the reflective structure of the present embodiment is a member that supports the first reflective film, the second reflective film, and the like, and is a member for arranging the first reflective film and the second reflective film to be separated from each other in the thickness direction.

[0175] The transparent substrate has light transmittance. As the light transmittance of the transparent substrate, the total light transmittance of the transparent substrate is preferably, for example, 80% or more, and preferably 90% or more. It should be noted that the total light transmittance of the transparent substrate can be measured, for example, by a method based on JIS K7361-1:1997. As a light source, CIE standard light source D65 can be used.

[0176] The material constituting the transparent substrate may be any material having the above-mentioned total light transmittance, and examples thereof include resins such as polyethylene terephthalate, polycarbonate, acrylic, cycloolefin, polyester, polystyrene, and acryl styrene, and glasses such as quartz glass, Pyrex (registered trademark), and synthetic quartz.

[0177] As for the thickness of the transparent substrate, for example, as shown in FIG8(b), it is preferably a thickness that enables light L12 incident at a high incident angle to the surface on the first reflective film 22 side of the reflective structure 20, that is, the surface 3A on the side where the first layer (not shown) of the reflective structure 20 (second layer) is arranged to be emitted from the opening 23 of the first reflective film 22 and the opening 25 of the second reflective film 24, and is appropriately set according to the spacing and size of the openings of the first reflective film and the second reflective film, or the thickness of the first reflective film and the second reflective film, etc. Specifically, the thickness of the transparent substrate can be set to be 0.05 mm or more and 2 mm or less, and preferably 0.1 mm or more and 0.5 mm or less.

[0178] (Second embodiment of the reflective structure)

[0179] The second mode of the reflective structure disclosed in the present invention comprises: a transparent substrate; a patterned convex portion having light transmittance, which is arranged on one surface of the transparent substrate; a patterned first reflective film, which is arranged on the surface side of the convex portion opposite to the surface on the transparent substrate side; and a patterned second reflective film, which is arranged on the opening of the convex portion on one surface of the transparent substrate, the opening of the first reflective film and the opening of the second reflective film being positioned so as not to overlap when viewed from above, and the first reflective film and the second reflective film being arranged separately in the thickness direction. In the case of the reflective structure of this mode, in the diffuser component disclosed in the present invention, the first layer is arranged on the surface side of the reflective structure on the first reflective film side.

[0180] Fig. 9 (a) and (b) are a schematic plan view and a cross-sectional view showing an example of the second embodiment of the reflective structure in the present disclosure, Fig. 9 (a) is a top view of the reflective structure as viewed from the first reflective film side. Fig. 9 (b) is Fig. 9 (a) AA line cross-sectional view. Fig. 9 As shown in (a) and (b) of FIG. 1 , the reflective structure 20 includes: a transparent substrate 21; a patterned convex portion 26 having light transmittance, which is arranged on one surface of the transparent substrate 21; a patterned first reflective film 22, which is arranged on the surface of the convex portion 26 opposite to the surface on the transparent substrate 21 side; and a patterned second reflective film 24, which is arranged at the opening of the convex portion 26 on one surface of the transparent substrate 21. The opening 23 of the first reflective film 22 and the opening 25 of the second reflective film 24 are positioned so as not to overlap when viewed from above. In addition, the first reflective film 22 and the second reflective film 24 are separated by the convex portion 26 and are arranged separately in the thickness direction.

[0181] In such a reflective structure, a patterned first reflective film and a second reflective film are stacked, and the opening of the first reflective film and the opening of the second reflective film are positioned so as not to overlap when viewed from above. Therefore, when a diffusion component having a reflective structure of this embodiment is used for an LED backlight, at least one of the first reflective film and the second reflective film is necessarily present directly above the LED element. Therefore, similarly to the first embodiment, for example, Fig. 9 As shown in (b), the light L11 incident at a low incident angle with respect to the surface on the first reflective film 22 side of the reflective structure 20, that is, the surface 3A on the side where the first layer (not shown) of the reflective structure 20 (second layer) is arranged can be reflected on the first reflective film 22 and the second reflective film 24. In addition, since the opening of the first reflective film and the opening of the second reflective film are positioned so as not to overlap when viewed from above, and the first reflective film and the second reflective film are arranged separately in the thickness direction, the light L12 incident at a high incident angle with respect to the surface on the first reflective film 22 side of the reflective structure 20, that is, the surface 3A on the side where the first layer (not shown) of the reflective structure 20 (second layer) is arranged can be emitted from the side surface of the protrusion 26 and the opening 25 of the second reflective film 24. Thus, part of the light emitted from the LED element and then emitted from the second layer side surface of the diffusion member can be emitted from a position away from the LED element in the in-plane direction, rather than being emitted from directly above the LED element. Therefore, the in-plane uniformity of brightness can be improved.

[0182] In addition, in this embodiment, since the convex portion is provided, self-alignment of the openings of the first reflection film and the second reflection film can be performed, and the manufacturing cost can be reduced.

[0183] In addition, the materials of the first reflective film and the second reflective film, the pitch between the openings of the first reflective film and the second reflective film, the size of the openings of the first reflective film and the second reflective film, the shape of the openings of the first reflective film and the second reflective film, the thickness of the first reflective film and the second reflective film, and the method for forming the first reflective film and the second reflective film can be the same as the above-mentioned first embodiment.

[0184] In addition, the transparent substrate can be the same as that in the above-mentioned first embodiment.

[0185] The convex portion in the reflective structure of the present embodiment is a member for arranging the first reflective film and the second reflective film described above to be separated from each other in the thickness direction.

[0186] The convex portion is light-transmissive. As the light transmittance of the convex portion, the total light transmittance of the convex portion is preferably, for example, 80% or more, and preferably 90% or more. It should be noted that the total light transmittance of the convex portion can be measured, for example, by a method based on JIS K7361-1:1997. As a light source, CIE standard light source D65 can be used.

[0187] The material constituting the convex portion may be any material as long as it can form the convex portion in a pattern and has the above-mentioned total light transmittance, and examples thereof include thermosetting resins and electron beam curable resins.

[0188] As the height of the convex portion, for example Fig. 9 As shown in (b), it is preferred that the height at which the light L12 incident at a high incident angle onto the surface on the first reflective film 22 side of the reflective structure 20, that is, onto the surface 3A on the side where the first layer (not shown) of the reflective structure 20 (second layer) is arranged, is emitted from the side surface of the convex portion 26 and the opening 25 of the second reflective film 24 is appropriately set according to the spacing and size of the openings of the first reflective film and the second reflective film, the thickness of the first reflective film and the second reflective film, etc. Specifically, the height of the convex portion can be set to be greater than 0.05 mm and less than 2 mm, and preferably greater than 0.1 mm and less than 0.5 mm.

[0189] The pitch, size, and planar shape of the convex portions may be the same as the pitch, size, and shape of the openings of the second reflective film.

[0190] The surface of the protrusion may be, for example, Fig. 9 (b) is a smooth surface, or Fig.10 When the surface of the convex portion is a rough surface, light diffusing properties can be imparted to the convex portion.

[0191] In addition, the shape of the surface of the convex portion may be, for example, Fig. 9 It can be a plane as shown in (b) or it can be Fig.10 When the surface of the convex portion is a curved surface, light diffusibility can be imparted to the convex portion.

[0192] The method for forming the convex portions is not particularly limited as long as it is a method that can form the convex portions in a pattern, and examples thereof include a printing method and resin forming using a mold.

[0193] (3) Reflective diffraction grating

[0194] When the second layer is a reflective diffraction grating, the reflective diffraction grating is not particularly limited as long as it has the above-mentioned incidence angle dependence of reflectivity and transmittance.

[0195] The spacing of the reflective diffraction grating can be appropriately adjusted as long as the above-mentioned incident angle dependence of the reflectivity and transmittance can be obtained. Specifically, when the wavelength output by the LED element is a single color such as red, green, and blue, by setting the spacing corresponding to each wavelength, the light of the LED element can be effectively reflected.

[0196] As a material constituting the reflective diffraction grating, any material that can obtain a reflective diffraction grating having the above-mentioned incident angle dependence of reflectivity and transmittance can be used, and a material commonly used for a reflective diffraction grating can be used. In addition, the method for forming the reflective diffraction grating can be the same as the method for forming a general reflective diffraction grating.

[0197] 3. Diffusion components

[0198] In the present embodiment, the overall thickness of the diffusion member can be set to, for example, 30 μm or more and 200 μm or less.

[0199] 4. Wavelength conversion components

[0200] In the diffusion component of the present disclosure, for example, Fig.11 As shown in (a) of FIG. 1 , a wavelength conversion member 4 may be arranged on the surface side of the second layer 3 opposite to the surface on the first layer 2 side. Alternatively, Fig.11 As shown in (b), a wavelength conversion component 4 is arranged on the surface side of the first layer 2 opposite to the surface on the second layer 3 side. In LED backlights, wavelength conversion components are sometimes used to achieve a wide color gamut, etc. When the diffusion component disclosed in the present invention is used in an LED backlight, the wavelength conversion component can also be combined with the diffusion component.

[0201] The wavelength conversion member is a member containing a phosphor that absorbs light emitted from an LED element and emits excitation light. The wavelength conversion member has a function of generating white light by combining with an LED substrate.

[0202] The wavelength conversion component usually has at least a wavelength conversion layer containing a phosphor and a resin. The wavelength conversion component can be, for example, a wavelength conversion layer monomer, or a laminate having a wavelength conversion layer on one side of a transparent substrate. Among them, from the perspective of thinning, a wavelength conversion layer monomer is preferred. It is more preferred to use a sheet-shaped wavelength conversion component.

[0203] As the above-mentioned phosphor, it can be appropriately selected according to the luminous color from the LED element, for example, blue phosphor, green phosphor, red phosphor, yellow phosphor, etc. can be listed. For example, when the LED element is a blue LED element, as the phosphor, green phosphor and red phosphor can be used, and yellow phosphor can also be used. In addition, for example, when the LED element is an ultraviolet LED element, as the phosphor, red phosphor, green phosphor and blue phosphor can be used.

[0204] As the phosphor, a phosphor generally used for a wavelength conversion member of an LED backlight can be used. Alternatively, quantum dots can be used as the phosphor.

[0205] The content of the phosphor in the wavelength conversion component layer is not particularly limited as long as it is sufficient to generate the desired white light when the diffusion component of the present disclosure is used in an LED backlight, and may be the same as the content of the phosphor in the wavelength conversion component of a general LED backlight.

[0206] The resin contained in the wavelength conversion component is not particularly limited as long as it can disperse the phosphor. The above resin can be the same as the resin used in the wavelength conversion component of the conventional LED backlight, for example, thermosetting resins such as silicone resins and epoxy resins can be listed.

[0207] The thickness of the wavelength conversion member is not particularly limited as long as it is a thickness that can generate desired white light when the diffusion member of the present disclosure is used in an LED backlight, and can be, for example, 10 μm or more and 1000 μm or less.

[0208] As a method of laminating a wavelength conversion component on the first layer or the second layer, for example, there can be mentioned a method of laminating the wavelength conversion component to the first layer or the second layer via an adhesive layer or a bonding layer, a method of directly forming the wavelength conversion component on the surface of the first layer or the second layer, etc. As a method of directly forming the wavelength conversion component on the surface of the first layer or the second layer, for example, there can be mentioned a printing method.

[0209] 5. Optical components

[0210] In the diffusion component of the present disclosure, for example Fig.11 As shown in (b), an optical component 5 may be further arranged on the surface side of the second layer 3 opposite to the surface on the first layer 2 side. In LED backlights, optical components are sometimes used in addition to diffusion components. When the diffusion component of the present disclosure is used for LED backlights, the diffusion component may be combined with the optical component. Examples of the optical component include prism sheets, reflective polarizers, and the like.

[0211] (1) Prism

[0212] The prism sheet disclosed in the present invention has the function of focusing incident light and improving the brightness in the front direction. The prism sheet is formed by, for example, arranging a prism pattern made of acrylic resin or the like on one side of a transparent resin substrate.

[0213] As the prism sheet, for example, a brightness enhancement film BEF series manufactured by 3M Company can be used.

[0214] (2) Reflective polarizer

[0215] The reflective polarizer disclosed in the present invention has the following functions: it allows only the first linear polarization component (for example, P polarization) to pass through, and does not absorb and reflects the second linear polarization component (for example, S polarization) that is orthogonal to the first linear polarization component. The second linear polarization component reflected by the reflective polarizer is reflected again, and is incident on the reflective polarizer again in a state where the polarization is eliminated (a state that includes both the first linear polarization component and the second linear polarization component). Therefore, the reflective polarizer allows the first linear polarization component in the light that is incident again to pass through, and reflects the second linear polarization component that is orthogonal to the first linear polarization component again. Next, by repeating the above process, about 70% to 80% of the light emitted from the above-mentioned second layer is emitted as light that becomes the first linear polarization component. Therefore, when the LED backlight having the diffusion component of the present disclosure is used in a display device, by making the polarization direction of the first linear polarization component (transmission axis component) of the reflective polarizer consistent with the transmission axis direction of the polarizer of the display panel, all the emitted light from the LED backlight can be used to form an image in the display panel. Therefore, even if the light energy input from the LED element is the same, a higher brightness image can be formed compared to the case where the reflective polarizer is not configured.

[0216] As the reflective polarizer, for example, there can be mentioned the brightness enhancement film DBEF series manufactured by 3M Co. In addition, as the reflective polarizer, for example, the high brightness polarizer WRPS manufactured by Shinwha Intertek Co., Ltd., the wire grid polarizer, etc. can also be used.

[0217] 6. Purpose

[0218] The diffusion component disclosed in the present invention is suitable for use in a direct-lit LED backlight source.

[0219] II. Second Embodiment of Diffuser Member

[0220] The second embodiment of the diffusion member disclosed herein is a member having a transmissive diffraction grating or a microlens array and a dielectric multilayer film. The diffusion member of the second embodiment of the disclosure uses the surface on the transmissive diffraction grating or microlens array side as a light incident surface when used.

[0221] In the second embodiment of the diffusion member of the present disclosure, the same effects as those of the first embodiment of the diffusion member described above can be achieved by combining a transmission-type diffraction grating or a microlens array with a dielectric multilayer film.

[0222] The transmission type diffraction grating and the microlens array in this embodiment can be the same as the transmission type diffraction grating and the microlens array used for the first layer in the first embodiment of the above-mentioned diffusion member.

[0223] The dielectric multilayer film in this embodiment may be the same as the dielectric multilayer film used for the second layer in the above-mentioned first embodiment of the diffusion member.

[0224] The transmission type diffraction grating and the microlens array may have any structure as long as they can exhibit light diffusivity, and for example, they may have a structure that exhibits light diffusivity in the entire layer or in a surface.

[0225] As for the configuration of the transmission type diffraction grating or microlens array and the dielectric multilayer film, for example, the transmission type diffraction grating or microlens array can be configured on one surface of the dielectric multilayer film via an adhesive layer or a bonding layer, or the transmission type diffraction grating or microlens array can be configured on one surface of the dielectric multilayer film via a gap portion, or the transmission type diffraction grating or microlens array can be directly configured on one surface of the dielectric multilayer film.

[0226] In the case where the transmission type diffraction grating or microlens array and the dielectric multilayer film are arranged with a gap portion therebetween, the transmission type diffraction grating or microlens array and the dielectric multilayer film may or may not be in contact. In the case where the transmission type diffraction grating or microlens array and the dielectric multilayer film are not in contact, for example, a spacer can be arranged between the transmission type diffraction grating or microlens array and the dielectric multilayer film. In addition, the gap portion may be an air layer.

[0227] In addition, when a transmission type diffraction grating or a microlens array is directly configured on one surface of a dielectric multilayer film, for example, the transmission type diffraction grating or the microlens array can be directly formed on one surface of the dielectric multilayer film by printing or mold-based resin forming.

[0228] The overall thickness of the diffusion member of the present embodiment can be made the same as the overall thickness of the diffusion member of the above-mentioned first embodiment.

[0229] In the diffusion component of this embodiment, the wavelength conversion component can be arranged on the surface side of the dielectric multilayer film opposite to the surface on the side of the transmission type diffraction grating or microlens array, and the wavelength conversion component can also be arranged on the surface side of the transmission type diffraction grating or microlens array opposite to the surface on the side of the dielectric multilayer film. In addition, the wavelength conversion component can be the same as the wavelength conversion component described in the first embodiment of the above-mentioned diffusion component.

[0230] In the diffusion component of this embodiment, an optical component may be arranged on the surface side of the dielectric multilayer film opposite to the surface on the transmission type diffraction grating or microlens array side. It should be noted that the optical component may be the same as the optical component described in the first embodiment of the diffusion component described above.

[0231] The diffusion member of this embodiment is suitable for use in a direct-type LED backlight.

[0232] B. Laminated body

[0233] The laminated body of the present disclosure has two embodiments. Each embodiment will be described below.

[0234] I. First Embodiment of Laminated Body

[0235] The first embodiment of the laminated body disclosed in the present invention is a component comprising: a diffusion component having a first layer and a second layer in sequence; and a sealing material sheet, which is arranged on the surface side of the first layer side of the diffusion component and is used to seal the LED element, wherein the first layer has light transmittance and light diffusivity, and the second layer has a reflectivity that increases as the absolute value of the incident angle of light relative to the surface of the second layer on the first layer side decreases, and a transmittance that increases as the absolute value of the incident angle of light relative to the surface of the second layer on the first layer side increases, and the sealing material sheet is composed of a sealing material composition containing a thermoplastic resin. When the laminated body disclosed in the present invention is used, the surface on the sealing material sheet side is used as the incident surface of light of the LED element.

[0236] Fig.12 1 is a schematic cross-sectional view showing an example of the first embodiment of the laminated body disclosed in the present invention. Fig.12 As shown in the example, the laminate 40 includes: a diffusion member 1 having a first layer 2 and a second layer 3 in this order; and a sealing material sheet 21a, which is arranged on the surface side of the first layer 2 side of the diffusion member 1 and is used to seal the LED element. The first layer 2 of the diffusion member 1 has light transmittance and light diffusibility. With respect to the second layer 3 of the diffusion member 1, as the absolute value of the incident angle of light relative to the surface of the first layer 2 side of the second layer 3 becomes smaller, the reflectivity becomes larger, and as the absolute value of the incident angle of light relative to the surface of the first layer 2 side of the second layer 3 becomes larger, the transmittance becomes larger. The sealing material sheet 21a is composed of a sealing material composition containing a thermoplastic resin.

[0237] Here, the direct-type LED backlight is disadvantageous in terms of thinning and weight reduction compared to the edge-light type. However, in the direct-type LED backlight, it is difficult to achieve thinning as described above.

[0238] However, in recent years, research and development on miniaturization and high density of LED elements has been promoted, and LEDs with small chip sizes, so-called mini LEDs or micro LEDs, have attracted attention. In addition, research is being conducted on the practical application of miniaturization and high density of LED elements as LED backlight sources. (For example, see Patent Document 4)

[0239] In a direct-type LED backlight source, the brightness unevenness depends on the distance between the LED element and the diffusion plate and the distance between the LED elements (hereinafter sometimes referred to as the spacing). Therefore, by shortening the distance between the LED elements, the brightness unevenness can also be suppressed. That is, by arranging fine LED elements at a high density, the in-plane uniformity of the brightness can be improved. In this case, thinning can be achieved.

[0240] Here, in the LED backlight, a spacer is arranged to maintain a predetermined distance between the LED element and the diffusion plate. However, the light emitted from the LED element is blocked or reflected by the spacer, which sometimes causes uneven brightness. In addition, multiple spacers need to be provided, but it is difficult to arrange multiple spacers in the case of a small pitch such as mini LED and micro LED.

[0241] Therefore, in the LED backlight source, a structure in which a sealing member is arranged between the LED element and the diffusion plate to seal the LED element has also been proposed (for example, see Patent Document 4). However, compared with a structure in which there is a space between the LED element and the diffusion plate, the weight of the structure in which a sealing member is arranged between the LED element and the diffusion plate increases.

[0242] In recent years, there is a demand for thinner and lighter display devices, and a demand for further thinning and lighter backlights assembled in display devices. As mentioned above, direct-type LED backlights are disadvantageous in thinning and lighter weight compared to edge-light types, and therefore further improvements are required.

[0243] According to the present disclosure, by providing the above-mentioned diffusion member, it is possible to improve the in-plane uniformity of brightness and achieve thinning. In addition, since the distance between the LED element and the diffusion member can be shortened, the thickness of the sealing material sheet can be reduced, and weight can also be reduced.

[0244] In the present disclosure, the sealing material sheet is composed of a sealing material composition containing a thermoplastic resin. The reason why a thermoplastic resin is preferred will be described below.

[0245] When the sealing member in the LED backlight contains a thermoplastic resin, a sheet-shaped sealing material (hereinafter, sometimes referred to as a sealing material sheet) composed of a sealing material composition containing a thermoplastic resin can be used. Fig.13 (a) to (b) are process diagrams showing an example of a method for manufacturing an LED backlight of the present disclosure, and are examples of using the laminate of the present disclosure. Fig.13As shown in (a), a stacked body 40 of an LED substrate 11, a diffusion component 1 and a sealing material sheet 21a is prepared, and after the sealing material sheet 21a is stacked on the surface side of the LED substrate 11 on the LED element 13 side, the sealing material sheet 21a is pressed onto the LED substrate 11 by, for example, using a vacuum lamination method, so that Fig.13 As shown in (b), the LED element 13 can be sealed with the sealing member 21. Fig.13 (a) and (b) show an example in which a reflective layer 15 is arranged on the surface of the support substrate 12 on which the LED element 13 is arranged and in an area other than the LED element mounting area on which the LED element 13 is mounted in the LED substrate 11.

[0246] On the other hand, in LED backlights, when the sealing component contains a curable resin such as a thermosetting resin or a photocurable resin, a liquid sealing material is generally used. Fig.14 As shown in (a), a mold 101 is arranged around the LED substrate 11, and a liquid sealing material 21b containing a curable resin is applied to the surface side of the LED substrate 11 on the LED element 13 side to form a coating film, and then the coating film is cured by heat treatment, so as to Fig.14 As shown in (b) of FIG. 1 , the LED element 13 can be sealed by the sealing member 21 ′.

[0247] In the case of a curable resin, since a liquid sealing material is used, the thickness of the end portion may become thicker or thinner than the center portion due to surface tension and the like (see Fig.14 (a)).

[0248] In addition, in the case of a curable resin, volume shrinkage and the like are likely to occur during curing, resulting in Fig.14 As shown in (b), sometimes the thickness of the central part and the end part of the cured sealing part becomes uneven. Fig.14 (b) shows an example in which the thickness of the end portion of the sealing member 21 ′ is thicker than the thickness of the central portion, but the thickness distribution is not limited to this. For example, there is a case in which the thickness of the end portion is thinner than the thickness of the central portion.

[0249] Thus, when the thickness of the center and the end of the sealing member are different, for example, when a plurality of LED backlight sources are spliced ​​together to achieve a larger size, the thickness of the boundaries of the respective LED backlight sources is different, and as a result, the backlight sources are recognized as seams. Therefore, when the spliced ​​LED backlight sources are used in a display device, the aesthetics of the display as the display device may be impaired.

[0250] In contrast, when a sheet-like seal is used, the surface unevenness of the sealing component, such as the thickness distribution of the coating caused by surface tension and the thickness distribution caused by thermal shrinkage or light shrinkage, which is generated when a liquid sealing material is used, can be avoided. Therefore, a sealing component with good flatness can be obtained, and a high-quality display device can be provided. Therefore, according to the present disclosure, a sealing component with good flatness can be obtained by having the above-mentioned sealing material sheet. In particular, it is useful when splicing LED substrates of a size called mini LED or micro LED.

[0251] Hereinafter, a first embodiment of the laminated body of the present disclosure will be described.

[0252] 1. Diffusion components

[0253] The diffusion member of the present disclosure is the same as that described in the above-mentioned section "A. Diffusion member I. First embodiment".

[0254] The arrangement of the diffusion member and the sealing material sheet is appropriately selected according to the type of the first layer of the diffusion member, for example. Fig.12 As shown, the first layer 2 can be directly disposed on one surface of the second layer 3 of the diffusion member 1 or through an adhesive layer or bonding layer not shown, and the sealing material sheet 21a can be directly disposed on the surface side of the first layer 2 of the diffusion member 1. Fig.15 As shown in (a), the first layer 2 is disposed on one surface of the second layer 3 of the diffusion component 1 directly or via an adhesive layer or bonding layer not shown, and a sealing material sheet 21a is disposed on the surface side of the first layer 2 of the diffusion component 1 via a low refractive index layer 43. Fig.15 As shown in (b) of FIG. 1 , the first layer 2 of the diffusion member 1 is directly arranged on one surface of the sealing material sheet 21a, and a gap is arranged between the first layer 2 and the second layer 3 of the diffusion member 1. Fig.15 As shown in (c), the first layer 2 is directly arranged on one surface of the second layer 3 of the diffusion component 1, and a gap portion is arranged between the diffusion component 1 and the sealing material sheet 21a. In the case where the first layer of the diffusion component is, for example, a resin film containing a diffusing agent, any of the above-mentioned configurations of the diffusion component and the sealing material sheet can be used. On the other hand, in the case where the first layer of the diffusion component is, for example, a transmission-type diffraction grating or a microlens array, it is necessary to arrange a gap portion between the first layer and the second layer of the diffusion component, or to arrange a gap portion between the first layer of the diffusion component and the sealing material sheet, or to arrange a low refractive index layer between the first layer of the diffusion component and the sealing material sheet.

[0255] In addition, when the first layer of the diffusion member is directly arranged on one surface of the sealing material sheet, for example Fig.15As shown in (b), the first layer 2 may be arranged in a pattern on one surface of the sealing material sheet 21a. For example, when the first layer exhibits light diffusibility on the surface, the light diffusibility can be exhibited even when the first layer is arranged in a pattern.

[0256] When a gap is provided between the first layer and the second layer of the diffusion member, for example Fig.15 As shown in (b), the first layer 2 and the second layer 3 may be in contact, but although not shown, the first layer and the second layer may not be in contact. In the case where the first layer and the second layer are not in contact, for example, a spacer may be arranged between the first layer and the second layer. In addition, in the case where a gap is arranged between the diffusion component and the sealing material sheet, for example, the first layer of the diffusion component and the sealing material sheet may be in contact, such as Fig.15 As shown in (c), the first layer of the diffusion component and the sealing material sheet may not be in contact. In the case where the first layer of the diffusion component and the sealing material sheet are not in contact, for example, a spacer may be arranged between the diffusion component and the sealing material sheet. In addition, the gap may be an air layer.

[0257] When the first layer of the diffusion member is directly disposed on one surface of the sealing material sheet, the first layer of the diffusion member can be directly formed on one surface of the sealing material sheet by, for example, a printing method or resin forming using a mold.

[0258] 2. Sealing material sheet

[0259] The sealing material sheet disclosed in the present invention is used for sealing an LED element, and is a member composed of a sealing material composition containing a thermoplastic resin.

[0260] The sealing material sheet has light translucency. It should be noted that the terms “light translucency” and “transparency” in the sealing material sheet may be transparent to a degree that does not hinder visibility of light from the LED element.

[0261] (1) Materials of Sealing Material Sheet

[0262] The sealing material sheet of the present disclosure is composed of a sealing material composition containing a thermoplastic resin.

[0263] As the thermoplastic resin used in the sealing material sheet of the present disclosure, a resin that substantially does not produce components that degrade the LED substrate (degradation components) is generally used. Here, "resin that substantially does not produce degradation components" refers to a resin that does not contain degradation components themselves or, even if it contains them, does not affect the degradation of the LED substrate, and a resin that does not produce degradation components during the manufacture and use of the LED backlight source or, even if it produces them, does not affect the degradation of the LED substrate.

[0264] Examples of resins that generate such deterioration components include ethylene-vinyl acetate copolymers (EVA) that generate acid components as deterioration components.

[0265] In addition, as the thermoplastic resin of the present disclosure, it is preferable to use a thermoplastic resin having a melt viscosity that allows the resin to follow the irregularities of the LED element and other components disposed on one surface of the LED substrate and enter the gaps when heated.

[0266] Specifically, the melt mass flow rate (MFR) of the thermoplastic resin used is preferably 0.5 g / 10 minutes or more and 40 g / 10 minutes or less, and more preferably 2.0 g / 10 minutes or more and 40 g / 10 minutes or less. The reason is that by making the MFR within the above range, it can enter the gap between the LED elements, can exert sufficient sealing performance, and can become a sealing component with excellent adhesion to the LED substrate.

[0267] It should be noted that MFR in this specification refers to a value measured at 190°C and a load of 2.16 kg in accordance with JIS K7210. MFR of a polypropylene resin also refers to a value of MFR at 230°C and a load of 2.16 kg in accordance with JIS K7210.

[0268] When the sealing material sheet is a multilayer member as described below, the MFR is measured by the above-mentioned measurement method in a multilayer state in which all layers are integrally laminated, and the measured value is defined as the MFR value of the multilayer sealing member.

[0269] The melting point of the thermoplastic resin used in the present disclosure is not particularly limited as long as the LED element can be sealed in a temperature range that does not deteriorate the LED substrate, and is preferably, for example, 55° C. or higher and 135° C. or lower. It should be noted that the melting point of the thermoplastic resin can be measured, for example, by differential scanning calorimetry (DSC) based on the transition temperature measurement method for plastics (JIS K7121).

[0270] In the present disclosure, as the thermoplastic resin, for example, an olefin-based resin, an ionomer-based resin, a polyvinyl butyral-based resin, or the like can be used.

[0271] Among them, the thermoplastic resin is preferably an olefin resin. This is because olefin resins are particularly unlikely to produce components that deteriorate the LED substrate, and have low melt viscosity, so they can well seal the LED element. In addition, among olefin resins, polyethylene resins or polypropylene resins are preferred.

[0272] Here, the polyethylene resin in this specification includes not only ordinary polyethylene obtained by polymerizing ethylene, but also resins obtained by polymerizing compounds having ethylenically unsaturated bonds such as α-olefins, resins obtained by copolymerizing a variety of different compounds having ethylenically unsaturated bonds, and modified resins obtained by grafting other chemical species onto these resins.

[0273] Among them, a silane copolymer (hereinafter also referred to as "silane copolymer") obtained by copolymerizing an α-olefin and an ethylenically unsaturated silane compound as a comonomer can be preferably used. This is because by using such a resin, a higher adhesion between the LED substrate and the sealing component can be obtained. The above-mentioned silane copolymer can use the substance described in Japanese Patent Publication No. 2018-50027.

[0274] (2) Structure of Sealing Material Sheet

[0275] Regarding the sealing material sheet of the present disclosure, for example Fig.12 As shown, the sealing material sheet 21a may be a single-layer member composed of a single resin layer, or may be Fig.16 As shown, the sealing material sheet 21a is a laminated resin layer ( Fig.16 A multi-layer component (3 layers in the figure).

[0276] In the case of the multilayer component, a material which is usually expensive and has good adhesion or moldability to enter the gap of the LED element etc. can be used in the layer located on the side opposite to the diffusion component side in the multilayer component, that is, the layer located on the LED substrate side. The multilayer component may have a two-layer structure, but preferably has a three-layer structure in which layers with good adhesion are arranged on both surfaces.

[0277] In the above-mentioned multilayer component, the material constituting the layer located on the opposite side of the diffusion component side, that is, the layer arranged on the LED substrate side, is not particularly limited as long as it is a material with high adhesion and high moldability. In the case of the above-mentioned thermoplastic resin, for example, the above-mentioned silane copolymer is preferably used. In addition, in the case of the above-mentioned thermoplastic resin, the above-mentioned material also preferably contains the above-mentioned olefin-based resin and a silane coupling agent.

[0278] The thickness of the sealing material sheet can be appropriately selected according to the layer structure of the LED substrate, etc., and is not particularly limited. The thickness of the sealing material sheet can be, for example, more than 100 μm, more than 250 μm, or more than 300 μm. In addition, the thickness of the sealing material sheet can be, for example, less than 600 μm, or less than 550 μm. If the above thickness is too thin, it may not be able to fully function as a sealing component or cause uneven brightness. On the other hand, if the above thickness is too thick, it may be difficult to achieve thinning and lightweight or it may have an adverse effect on light transmittance.

[0279] In addition, when the sealing material sheet is a multilayer component having three layers, the thickness of the layer located at the center of the three layers may be, for example, 60 μm or more, 100 μm or more, 250 μm or more, 400 μm or less, or 350 μm or less. In this case, the thickness of each layer located at the outer side of the three layers may be, for example, 15 μm or more and 200 μm or less.

[0280] It should be noted that the "thickness" in this specification can be measured using a known measurement method that can measure μ-level dimensions, and as an example, can be measured using an observation image obtained using an optical microscope or a scanning electron microscope (SEM). The same applies to the measurement of dimensions such as "size".

[0281] (3) Others

[0282] The sealing material composition used for the sealing material sheet only needs to contain a thermoplastic resin, and may contain other additives such as a crosslinking agent, a silane coupling agent, an antioxidant, and a light stabilizer as needed. In addition, the molding method of the sealing material sheet can be the same as the molding method of a general resin sheet. As an example, a T-die method can be cited, but it is not limited to this.

[0283] (4) Specific method of sealing material sheet

[0284] As described above, the sealing material sheet contains a thermoplastic resin, more preferably an olefin resin, and further preferably a polyethylene resin. It is particularly preferred that the sealing material sheet has a density of 0.870 g / cm 3 Above 0.930g / cm 3 The following polyethylene resin is used as the base resin. This is because such a sealing material sheet has good adhesion to the LED substrate and good followability to the components arranged on the LED substrate.

[0285] Hereinafter, the preferred sealing material sheet will be described in detail.

[0286] The sealing material sheet is 0.870g / cm 3 Above 0.930g / cm 3 The following resin film is a resin film having the polyethylene resin as a base resin. That is, the above-mentioned sealing material sheet is a sealing material sheet having the above-mentioned polyethylene resin as a base resin.

[0287] The sealing material sheet is preferably a multilayer film composed of a core layer and a plurality of layers disposed on the two outermost surfaces. In this case, the core layer is preferably 0.910 g / cm 3 Above 0.930g / cm 3The following polyethylene resin is used as the base resin, and the surface layer preferably has a density of 0.890 g / cm 3 Above 0.910g / cm 3 The base resin is a polyethylene resin having a density lower than that of the base resin for the core layer.

[0288] In the case of the above-mentioned multilayer film, the total thickness is preferably, for example, 100 μm or more, more preferably 250 μm or more, and further preferably 300 μm or more. In addition, the total thickness is preferably, for example, 600 μm or less, and more preferably 550 μm or less. If the total thickness is too thin, the impact cannot be fully mitigated, but if the total thickness is within the above range, both formability and heat resistance can be achieved at a sufficiently preferred level. It should be noted that if the total thickness is too thick, it is difficult to obtain a further improvement in the buffering effect, and it is also impossible to cope with the requirements for thinning, and it is uneconomical.

[0289] The thickness of the core layer in the multilayer film is preferably, for example, 60 μm or more, more preferably 100 μm or more, and further preferably 250 μm or more. In addition, the thickness of the core layer is preferably, for example, 400 μm or less, and more preferably 350 μm or less. In addition, the thickness of each layer of the surface layer in this case can be, for example, 15 μm or more, or 30 μm or more, or 200 μm or less. By making the thickness of each layer within such a range, the heat resistance and molding characteristics of the sealing material sheet can be maintained within a good range.

[0290] The sealing material sheet is obtained by molding a sealing material composition described in detail below into a sheet shape by a conventionally known method.

[0291] When the sealing material sheet is formed as a sealing member, the sealing material composition used for producing each layer has a composition having a different density range and the like for each layer as a base resin.

[0292] In this case, the sealing material composition is used separately as a core layer sealing material composition and a surface layer sealing material composition in the formation of each layer. Then, the core layer sealing material composition and the surface layer sealing material composition are used to form a multilayer film with a three-layer structure with surface layers arranged on the two outermost surfaces at a predetermined thickness, thereby, for example, Fig.16 As shown, a sealing material sheet 21a having a three-layer structure of the surface layer 22a, the core layer 23 and the surface layer 22b can be manufactured.

[0293] As the base resin of the sealing material composition for the core layer of the sealing material sheet, a low-density polyethylene resin (LDPE), a linear low-density polyethylene resin (LLDPE), or a metallocene linear low-density polyethylene resin (M-LLDPE) can be preferably used. Among them, from the viewpoint of long-term reliability, a low-density polyethylene resin (LDPE) can be particularly preferably used as the composition for the core layer.

[0294] The density of the polyethylene resin used as the base resin of the sealing material composition for the core layer is 0.910 g / cm 3 Above 0.930g / cm 3 Below, more preferably 0.920 g / cm 3 By setting the density of the base resin of the sealing material composition for the core layer in the above range, it is possible to provide the sealing material sheet with sufficient heat resistance as required without undergoing a crosslinking treatment.

[0295] Regarding the melting point of the sealing material composition for the core layer, the melting point is preferably above 90°C and below 135°C, and more preferably above 100°C and below 115°C. By setting the melting point of the core layer to the above melting point range, the heat resistance and molding characteristics of these sealing material compositions can be maintained within a preferred range. It should be noted that by adding a high melting point resin such as polypropylene to the sealing material composition for the core layer, the melting point of the sealing material composition can be increased to about 135°C. In this case, relative to the total resin components of the core layer, it is preferred to contain more than 5% by mass and less than 40% by mass of polypropylene.

[0296] The polypropylene contained in the core layer is preferably a homopolymer polypropylene (homo PP) resin. Homo PP is a polymer consisting only of polypropylene monomers, and has high crystallinity, so it has higher rigidity than block PP and random PP. By using it as an added resin added to the sealing material composition for the core layer, the dimensional stability of the sealing component can be improved. In addition, with respect to the homo PP used as a resin added to the sealing material composition for the core layer, it is preferred that the MFR measured in accordance with JIS K7210 at 230°C and a load of 2.16kg is 5g / 10 minutes or more and 125g / 10 minutes or less. If the above-mentioned MFR is too small, the molecular weight becomes large, the rigidity becomes too high, and it is difficult to ensure the preferred sufficient softness of the sealing material composition. In addition, if the above-mentioned MFR is too large, the fluidity during heating cannot be fully suppressed, and the sealing material sheet cannot be fully given heat resistance and dimensional stability.

[0297] The melt mass flow rate (MFR) of the polyethylene resin used as the base resin of the sealing material composition for the above-mentioned core layer is preferably 2.0g / 10 minutes or more and 7.5g / 10 minutes or less at 190°C and a load of 2.16kg, and more preferably 3.0g / 10 minutes or more and 6.0g / 10 minutes or less. By making the MFR of the base resin of the sealing material composition for the core layer the above-mentioned range, the heat resistance and molding characteristics of the sealing component can be maintained within a preferred range. In addition, the processing adaptability during film making can be fully improved, which also contributes to the improvement of the productivity of the sealing component.

[0298] The content of the base resin relative to the total resin components in the core layer sealing material composition is 70% to 99% by mass, preferably 90% to 99% by mass. As long as the base resin is contained within the above range, other resins may be contained.

[0299] As the base resin of the sealing material composition for the surface layer of the sealing material sheet, the same as the sealing material composition for the core layer, a low-density polyethylene resin (LDPE), a linear low-density polyethylene resin (LLDPE), or a metallocene linear low-density polyethylene resin (M-LLDPE) can be preferably used. Among them, from the viewpoint of molding properties, a metallocene linear low-density polyethylene resin (M-LLDPE) can be particularly preferably used as the sealing material composition for the surface layer.

[0300] The density of the polyethylene resin used as the base resin of the sealing material composition for the surface layer is 0.890 g / cm 3 Above 0.910g / cm 3 Below, more preferably 0.899 g / cm 3 By setting the density of the base resin of the sealing material composition for the surface layer within the above range, the adhesion of the sealing member can be maintained within a preferred range.

[0301] The melting point of the surface layer sealing material composition is preferably 55° C. to 100° C., more preferably 80° C. to 95° C. By setting the melting point of the surface layer sealing material composition within the above range, the adhesion of the sealing member can be more reliably improved.

[0302] The melt mass flow rate (MFR) of the polyethylene resin used as the base resin of the sealing material composition for the above-mentioned surface layer is preferably 2.0g / 10 minutes or more and 7.0g / 10 minutes or less at 190°C and a load of 2.16kg, and more preferably 2.5g / 10 minutes or more and 6.0g / 10 minutes or less. By making the MFR of the base resin of the sealing material composition for the surface layer within the above range, the adhesion of the sealing material sheet can be more reliably maintained within the preferred range. In addition, the processing adaptability during film making can be fully improved, which contributes to the improvement of the productivity of the sealing material sheet.

[0303] The content of the base resin relative to the total resin components in the surface layer sealing material composition is 60% to 99% by mass, preferably 90% to 99% by mass. As long as the base resin is contained within the above range, other resins may be contained.

[0304] In all the sealing material compositions described above, it is more preferred that each sealing material composition contains a certain amount of silane copolymers obtained by copolymerizing α-olefins and ethylenically unsaturated silane compounds as comonomers as needed. Such graft copolymers can improve the adhesion of the sealing material sheet to other components because the degree of freedom of the silanol group that contributes to the adhesive force becomes higher.

[0305] As for the silane copolymer, for example, the silane copolymer described in Japanese Patent Application Publication No. 2003-46105 can be cited. By using the above-mentioned silane copolymer as a component of the sealing material composition, the strength and durability are excellent, and the weather resistance, heat resistance, water resistance, light resistance and other characteristics are excellent. Furthermore, it has extremely excellent heat-welding properties without being affected by the manufacturing conditions such as heating and pressing when configuring the sealing material sheet, and the sealing material sheet can be stably obtained at low cost.

[0306] As the silane copolymer, any of random copolymers, alternating copolymers, block copolymers and graft copolymers can be preferably used, and graft copolymers are more preferred, and graft copolymers obtained by polymerization with polyethylene as the main chain and ethylenically unsaturated silane compounds as side chains are further preferred. Such graft copolymers can improve the adhesion of the sealing material sheet because the degree of freedom of the silanol group that contributes to the adhesive force becomes higher.

[0307] The content of the ethylenically unsaturated silane compound in the copolymer of an α-olefin and an ethylenically unsaturated silane compound is, for example, 0.001% by mass or more and 15% by mass or less, preferably 0.01% by mass or more and 5% by mass or less, and particularly preferably 0.05% by mass or more and 2% by mass or less, relative to the total mass of the copolymer. When the content of the ethylenically unsaturated silane compound in the copolymer of an α-olefin and an ethylenically unsaturated silane compound is high, mechanical strength and heat resistance are excellent, but when the content is too high, tensile elongation and thermal fusion properties tend to deteriorate.

[0308] The content of the above-mentioned silane copolymer relative to the total resin components of the sealing material composition is preferably 2% by mass or more and 20% by mass or less in the sealing material composition for the above-mentioned core layer, and is preferably 5% by mass or more and 40% by mass or less in the sealing material composition for the above-mentioned surface layer. Particularly in the sealing material composition for the surface layer, it is more preferred to contain more than 10% by mass of the silane copolymer. It should be noted that the silane modification amount in the above-mentioned silane copolymer is preferably about 1.0% by mass or more and 3.0% by mass or less. The content range of the preferred silane copolymer in the above-mentioned sealing material composition is based on the above-mentioned silane modification amount being within the range, and it is desired to appropriately perform micro-adjustment according to the variation of the modification amount.

[0309] In all sealing material compositions, an adhesion improver can also be appropriately added. By adding an adhesion improver, the adhesion durability with other parts can be further improved. As the adhesion improver, known silane coupling agents can be used, and it is particularly preferred to use a silane coupling agent with an epoxy group or a silane coupling agent with a mercapto group.

[0310] 3. Wavelength conversion components

[0311] In the laminate of the present disclosure, for example, Fig.17 As shown in (a) of FIG. 1 , a wavelength conversion member 41 is disposed on the surface side of the second layer 3 of the diffusion member 1. Alternatively, Fig.17 As shown in (b) of FIG. 1 , a wavelength conversion member 41 is disposed between the diffusion member 1 and the sealing material sheet 21a. The wavelength conversion member may be the same as the wavelength conversion member described in the above-mentioned section "A. Diffusing member".

[0312] 4. Optical components

[0313] In addition, in the laminated body of the present disclosure, for example Fig.17 As shown in (b), an optical component 42 may be disposed on the surface side of the diffusion component 1 on the second layer 3 side. The optical component may be the same as the optical component described in the above-mentioned section "A. Diffusing component".

[0314] 5. Other structures

[0315] In the laminate of the present disclosure, for example Fig.15 As shown in (a), when a low refractive index layer 43 is arranged between the first layer 2 of the diffusion component 1 and the sealing material sheet 21a, the low refractive index layer is a layer having a refractive index lower than that of the first layer of the diffusion component. By making the refractive index of the low refractive index layer lower than that of the first layer of the diffusion component, total reflection can be suppressed. In addition, as described above, the laminate of the present embodiment is a laminate in which the surface on the side of the sealing material sheet is used as the incident surface of the light of the LED element. In the case where the first layer of the diffusion component is, for example, a transmission-type diffraction grating or a microlens array, a low refractive index layer having a refractive index different from that of the first layer is arranged on the light incident side of the first layer of the diffusion component, thereby making it possible to diffract the light using the transmission-type diffraction grating or refract the light using the microlens array.

[0316] The refractive index of the low refractive index layer only needs to be lower than the refractive index of the first layer of the diffusion component, and can be, for example, 1.0 or more and 1.5 or less. In addition, the refractive index difference between the low refractive index layer and the first layer of the diffusion component is preferably large, and can be, for example, 0.3 or more and 1.0 or less. By making the refractive index difference between the low refractive index layer and the first layer of the diffusion component large, the refraction angle can be increased when the first layer is, for example, a microlens array or a resin film containing a diffusing agent, and the diffraction angle can be increased when the first layer is, for example, a transmission type diffraction grating.

[0317] The low refractive index layer can contain resin and low refractive index particles, or can contain fluorine-containing resin. When the low refractive index layer contains resin and low refractive index particles, the low refractive index particles can be any of inorganic particles and organic particles. In addition, the low refractive index particles can also be hollow particles. In addition, as the resin, for example, curable resin can be used.

[0318] II. Second Embodiment of Laminated Body

[0319] The second embodiment of the laminated body disclosed in the present invention is a component comprising: a diffusion component having a transmission type diffraction grating or a microlens array and a dielectric multilayer film; and a sealing material sheet disposed on the surface side of the transmission type diffraction grating or the microlens array side of the diffusion component, for sealing an LED element, wherein the sealing material sheet is composed of a sealing material composition containing a thermoplastic resin. When the laminated body of this embodiment is used, the surface on the sealing material sheet side is used as an incident surface of light of the LED element.

[0320] In the second embodiment of the laminated body of the present disclosure, the same effects as those of the first embodiment of the laminated body described above can be achieved.

[0321] The diffusion member in this embodiment is the same as that described in the above-mentioned section "A. Diffusion member II. Second embodiment".

[0322] As for the configuration of the diffusion component and the sealing material sheet, for example, a transmission type diffraction grating or a microlens array can be configured directly on one surface of the dielectric multilayer film of the diffusion component or through a bonding layer or an adhesive layer, and a sealing material sheet can be configured on the surface side of the transmission type diffraction grating or microlens array of the diffusion component through a low refractive index layer. Alternatively, a transmission type diffraction grating or a microlens array of the diffusion component can be directly configured on one surface of the sealing material sheet, and a gap portion can be configured between the dielectric multilayer film of the diffusion component and the transmission type diffraction grating or the microlens array. Alternatively, a transmission type diffraction grating or a microlens array can be directly configured on one surface of the dielectric multilayer film of the diffusion component, and a gap portion can be configured between the diffusion component and the sealing material sheet.

[0323] The structure in which a gap is arranged between the transmission type diffraction grating or microlens array of the diffusion member and the dielectric multilayer film can be the same as the structure in which a gap is arranged between the first layer and the second layer of the diffusion member in the first embodiment of the above-mentioned laminate. In addition, the structure in which a gap is arranged between the diffusion member and the sealing material sheet can be the same as the structure in which a gap is arranged between the diffusion member and the sealing material sheet in the first embodiment of the above-mentioned laminate.

[0324] In the case where a transmission type diffraction grating or a microlens array of a diffusion component is directly arranged on one surface of the sealing material sheet, the transmission type diffraction grating or the microlens array of the diffusion component can be directly formed on one surface of the sealing material sheet by, for example, a printing method or a mold-based resin forming method.

[0325] In addition, the sealing material sheet in this embodiment may be the same as the sealing material sheet in the first embodiment of the above-mentioned laminated body.

[0326] In addition, the low refractive index layer in this embodiment may be the same as the low refractive index layer in the first embodiment of the above-mentioned laminate.

[0327] In the laminate of this embodiment, a wavelength conversion component may be arranged on the surface side of the dielectric multilayer film side of the diffusion component, or may be arranged between the diffusion component and the sealing material sheet. The wavelength conversion component may be the same as the wavelength conversion component described in the above-mentioned "A. Diffusion component".

[0328] In the laminate of the present embodiment, an optical component may be disposed on the surface of the diffusion member on the dielectric multilayer film side. The optical component may be the same as the optical component described in the above-mentioned section "A. Diffuser member".

[0329] C. Group of diffusion components

[0330] The group of diffusion components disclosed in the present invention comprises: a first component, which has a first layer and a sealing material sheet for sealing an LED element; and a second component, which has a second layer and is used by being arranged on the surface of the first layer side of the above-mentioned first component via a gap portion, the above-mentioned first layer has light transmittance and light diffusion properties, and with respect to the above-mentioned second layer, the reflectivity increases as the absolute value of the incident angle of light relative to the surface of the above-mentioned second layer on the side of the above-mentioned first layer decreases, and the transmittance increases as the absolute value of the incident angle of light relative to the surface of the above-mentioned second layer on the side of the above-mentioned first layer increases, and the above-mentioned sealing material sheet is composed of a sealing material composition containing a thermoplastic resin.

[0331] like Fig.18 As shown, the diffusion component group 60 includes: a first component 61 having a first layer 2 and a sealing material sheet 21a for sealing an LED element; and a second component 62 having a second layer 3. The second component 62 is used by being arranged on the surface of the first component 61 on the first layer 2 side via a gap. The first layer 2 has light transmittance and light diffusibility. In addition, the second layer 3 has incident angle dependence of reflectivity and incident angle dependence of transmittance.

[0332] The diffuser member assembly of the present disclosure can produce the same effects as those of the above-described laminated body.

[0333] The first member and the second member are different members, and by arranging the first member and the second member with the gap therebetween, they can be used as a diffusion member.

[0334] The first layer and the second layer of the present disclosure are the same as the first layer and the second layer described in the above-mentioned section "A. Diffusing member".

[0335] In addition, the sealing material sheet of the present disclosure is the same as the sealing material sheet described in the above-mentioned section "B. Laminated body".

[0336] In the first component, a wavelength conversion component may be arranged between the first layer and the sealing material sheet. On the other hand, in the second component, a wavelength conversion component may be arranged on one surface of the second layer. In addition, in the second component, an optical component may be arranged on one surface of the second layer. The wavelength conversion component and the optical component may be the same as the wavelength conversion component and the optical component described in the above-mentioned "A. Diffusing component".

[0337] D.LED backlight

[0338] The LED backlight disclosed in the present invention has two embodiments. Each embodiment will be described below.

[0339] I. First Embodiment of LED Backlight

[0340] The first embodiment of the LED backlight disclosed in the present invention is a device comprising: an LED substrate having a plurality of LED elements arranged on one surface side of a supporting substrate; and a diffusion component arranged on the surface side of the LED substrate on the LED element side, and having a first layer and a second layer in order from the LED substrate side, the first layer having light transmittance and light diffusion properties, and with respect to the second layer, as the absolute value of the incident angle of light relative to the surface of the second layer on the first layer side becomes smaller, the reflectivity becomes larger, and as the absolute value of the incident angle of light relative to the surface of the second layer on the first layer side becomes larger, the transmittance becomes larger. The LED backlight disclosed in the present invention is a direct-type LED backlight.

[0341] Figure 2 1 is a schematic cross-sectional view showing an example of an LED backlight of the present invention. Figure 2 Since it is recorded in the above-mentioned item “A. Diffusion component”, its description is omitted here.

[0342] Fig.19 FIG. 2 is a schematic cross-sectional view showing another example of the LED backlight of the present disclosure. Fig.19 As shown in the example, the LED backlight 10 includes: an LED substrate 11, on which a plurality of LED elements 13 are arranged on one side of a support substrate 12; a sealing member 21, which is arranged on the surface side of the LED substrate 11 on the LED element 13 side and seals the LED element 13; and a diffusion member 1, which is arranged on the surface side of the sealing member 21 on the side opposite to the surface on the LED substrate 11 side and has a first layer 2 and a second layer 3 in order from the sealing member 21 side. The first layer 2 in the diffusion member 1 has light transmittance and light diffusibility, and transmits and diffuses light L1, L2, and L2' incident from a surface 2A on the side opposite to the surface on the side of the second layer 3 of the first layer 2. In addition, with respect to the second layer 3 in the diffusion member 1, the reflectivity increases as the absolute value of the incident angle of light relative to the surface 3A on the side of the first layer 2 of the second layer 3 decreases, and the transmittance increases as the absolute value of the incident angle of light relative to the surface 3A on the side of the first layer 2 of the second layer 3 increases. Therefore, in the second layer 3, the light L1 incident at a low incident angle θ1 with respect to the surface 3A of the second layer 3 on the first layer 2 side can be reflected, and the light L1 incident at high incident angles θ2, θ3 and θ4 with respect to the surface 3A of the second layer 3 on the first layer 2 side can be reflected. 2’ The incident light L2 and L2' are transmitted. Fig.19 , an example is shown in which a reflective layer 15 is arranged on the surface of the support substrate 12 on which the LED element 13 is arranged, in the LED substrate 11, in a region other than the LED element mounting region on which the LED element 13 is mounted.

[0343] exist Fig.19 In this embodiment, light emitted from the LED element 13 and incident on the surface 1A on the first layer 2 side of the diffusion member 1 can be diffused in the first layer 2, and light L1 incident at a low incident angle θ1 with respect to the surface 3A on the first layer 2 side of the second layer 3 among the light diffused through the first layer 2 can be reflected at the surface 3A on the first layer 2 side of the second layer 3 and can be incident on the first layer 2 again and diffused. Furthermore, light L1 incident at a high incident angle θ2, θ4 and θ5 with respect to the surface 3A on the first layer 2 side of the second layer 3 among the light diffused through the first layer 2 can be diffused. 2’ The incident light L2 , L2 ′ can be transmitted through the second layer 3 and emitted from the surface 1B on the second layer 3 side of the diffusion member 1 .

[0344] In the present disclosure, by having the above-mentioned diffusion component, it is possible to achieve thinness while improving the in-plane uniformity of brightness. In addition, it is also possible to reduce costs and power consumption. In addition, since the distance between the LED element and the diffusion component can be shortened, the thickness of the sealing component can be reduced, and lightweighting can also be achieved. In addition, by using the above-mentioned diffusion component, the LED backlight source of the present disclosure can be easily manufactured.

[0345] Hereinafter, a first embodiment of the LED backlight of the present disclosure will be described.

[0346] 1. Diffusion components

[0347] The diffusion component disclosed in the present invention is arranged on the surface side of the above-mentioned LED substrate on the side of the above-mentioned LED element, and has a first layer and a second layer in sequence from the above-mentioned LED substrate side. The above-mentioned first layer has light transmittance and light diffusion. Regarding the above-mentioned second layer, the reflectivity increases as the absolute value of the incident angle of light relative to the surface of the above-mentioned second layer on the side of the above-mentioned first layer decreases, and the transmittance increases as the absolute value of the incident angle of light relative to the surface of the above-mentioned second layer on the side of the above-mentioned first layer increases.

[0348] The diffusion member of the present disclosure is the same as the member described in the above-mentioned section “A. Diffusion member”. The members constituting the diffusion member may be the same as those described in the above-mentioned section “A. Diffusion member”, and thus the description here is omitted.

[0349] The diffusion component is arranged at a predetermined distance from the light-emitting surface of the LED element of the LED substrate. The distance between the diffusion component and the light-emitting surface of the LED element of the LED substrate is preferably, for example, 5 mm or less, preferably 2 mm or less, and particularly preferably 1 mm or less. If the above distance is within the above range, thinning can be achieved. The lower limit of the above distance is not particularly limited.

[0350] Here, the distance between the diffusion member and the light emitting surface of the LED element of the LED substrate is, for example, Figure 2The distance d between the surface 1A on the first layer 2 side of the diffusion member 1 and the light emitting surface of the LED element 13 of the LED substrate 11 is shown.

[0351] 2.LED substrate

[0352] The LED substrate of the present disclosure is a component in which a plurality of LED elements are arranged on one surface side of a support substrate.

[0353] Next, the LED substrate will be described.

[0354] (1) LED components

[0355] In the LED backlight of the present disclosure, the LED element functions as a light source.

[0356] The LED backlight of the present disclosure may be a white LED. When the LED backlight is used, the LED element is not particularly limited as long as it can emit white light, and examples thereof include LED elements that can emit white, blue, ultraviolet, or infrared light.

[0357] The LED element may be a chip-shaped LED element. As the form of the LED element, for example, it may be a light-emitting portion (also referred to as an LED chip) itself, or it may be a packaged LED (also referred to as a chip LED) such as a surface-mounted type or a chip-on-board type. The packaged LED may, for example, have a light-emitting portion, and a protective portion that covers the light-emitting portion and contains a resin. Specifically, in the case where the LED element is the light-emitting portion itself, as the LED element, for example, a blue LED element, an ultraviolet LED element, or an infrared LED element can be used. In addition, in the case where the LED element is a packaged LED, as the LED element, for example, a white LED element can be used.

[0358] In the case where the LED backlight source disclosed in the present invention combines an LED element and a wavelength conversion component to irradiate white light, the LED element is preferably a blue LED element, an ultraviolet LED element, or an infrared LED element. The blue LED element can generate white light by, for example, combining with a yellow phosphor, or combining with a red phosphor and a green phosphor. In addition, the ultraviolet LED element can generate white light by, for example, combining with a red phosphor, a green phosphor, and a blue phosphor. Among them, the LED element is preferably a blue LED element. This is because, in the LED backlight source disclosed in the present invention, it can irradiate white light with high brightness.

[0359] In addition, when the LED element is a white LED element, as a white LED element, it is appropriately selected according to the light-emitting mode of the white LED element. As the light-emitting mode of the white LED element, for example, a combination of a red LED, a green LED and a blue LED, a combination of a blue LED, a red phosphor and a green phosphor, a combination of a blue LED and a yellow phosphor, a combination of an ultraviolet LED, a red phosphor, a green phosphor and a blue phosphor, etc. can be listed. Therefore, as a white LED element, for example, it can have a red LED light-emitting part, a green LED light-emitting part and a blue LED light-emitting part, it can also have a blue LED light-emitting part and a protective part containing a red phosphor and a green phosphor, it can also have a blue LED light-emitting part and a protective part containing a yellow phosphor, it can also have an ultraviolet LED light-emitting part, and a protective part containing a red phosphor, a green phosphor and a blue phosphor. Among them, it is preferred that the white LED element has a blue LED light-emitting part and a protective part containing a red phosphor and a green phosphor, a blue LED light-emitting part and a protective part containing a yellow phosphor, or an ultraviolet LED light-emitting part and a protective part containing a red phosphor, a green phosphor and a blue phosphor. The white LED element preferably has a blue LED light-emitting portion and a protective portion containing red and green phosphors, or has a blue LED light-emitting portion and a protective portion containing yellow phosphors, because in the LED backlight of the present disclosure, it can emit white light with high brightness.

[0360] The structure of the LED element can be the same as that of a general LED element.

[0361] The LED elements are usually arranged at equal intervals on one side of the support substrate. The arrangement of the LED elements can be appropriately selected according to the purpose and size of the LED backlight source of the present disclosure, the size of the LED elements, etc. In addition, the arrangement density of the LED elements is also appropriately selected according to the purpose and size of the LED backlight source of the present disclosure, the size of the LED elements, etc.

[0362] The size (chip size) of the LED element is not particularly limited and can be set to a general chip size. In addition, the size of the LED element may be a chip size called a mini LED or a micro LED. Among them, in the case where a sealing component is configured, the chip size called a mini LED is preferred. Specifically, the size of the LED element may be hundreds of microns square or tens of microns square. More specifically, the size of the LED element may be set to be greater than 100 μm square and less than 300 μm square. When the size of the LED element is small, the LED elements can be arranged at a high density, that is, the interval (pitch) between the LED elements can be reduced. Therefore, even if the distance between the LED substrate and the diffusion component is shortened, uneven brightness can be suppressed. Therefore, further thinning can be achieved. In addition, the distance between the LED substrate and the diffusion component can be shortened, that is, the thickness of the sealing component can be thinned, and lightweighting can be achieved.

[0363] (2)Support base plate

[0364] The supporting substrate of the present disclosure is a member that supports the above-mentioned LED element and the like.

[0365] The supporting substrate may be transparent or opaque. In addition, the supporting substrate may be flexible or rigid. The material of the supporting substrate may be an organic material, an inorganic material, or a composite material of an organic material and an inorganic material.

[0366] When the material of the supporting substrate is an organic material, a resin substrate can be used as the supporting substrate. On the other hand, when the material of the supporting substrate is an inorganic material, a ceramic substrate or a glass substrate can be used as the supporting substrate. In addition, when the material of the supporting substrate is a composite material, a glass epoxy substrate can be used as the supporting substrate. In addition, as the supporting substrate, for example, a metal core substrate can also be used. As the supporting substrate, a printed circuit substrate having a circuit formed thereon by printing can also be used.

[0367] The thickness of the support substrate is not particularly limited, and can be appropriately selected depending on whether it is flexible or rigid, the application and size of the LED backlight of the present disclosure, and the like.

[0368] (3) Others

[0369] The LED substrate disclosed in the present invention is not particularly limited as long as it has the above-mentioned supporting substrate and LED elements, and can appropriately have necessary structures. Such structures can include, for example, wiring parts, terminal parts, insulating layers, reflective layers, heat dissipation components, etc. Each structure can be the same as the structure used in the known LED substrate.

[0370] The wiring part is electrically connected to the LED element. The wiring part is usually arranged in a pattern. In addition, the wiring part can be arranged on the supporting substrate via an adhesive layer. As the material of the wiring part, for example, a metal material, a conductive polymer material, etc. can be used.

[0371] The wiring portion is electrically connected to the LED element via a bonding portion. As a material of the bonding portion, for example, a bonding agent or solder having a conductive material such as a metal or a conductive polymer can be used.

[0372] A reflective layer can be arranged on the surface of the support substrate where the LED element is arranged and in an area other than the LED element mounting area. The light reflected by the second layer of the diffusion component can be reflected on the reflective layer of the LED substrate and incident on the first layer of the diffusion component again, thereby improving the light utilization efficiency.

[0373] The reflective layer may be the same as the reflective layer commonly used in LED substrates. Specifically, as the reflective layer, white resin films, metal films, porous films, etc. containing metal particles, inorganic particles or pigments and resins may be cited. The thickness of the reflective layer is not particularly limited as long as it is a thickness that can obtain the desired reflectivity, and can be appropriately set.

[0374] The LED substrate may be formed by the same method as a known method.

[0375] 3. Other components

[0376] In the LED backlight source disclosed in the present invention, the LED substrate and the diffusion component may be connected as follows: Figure 2 As shown in the space, it can also be Fig.19 and Fig. 20 As shown in the figure, sealing members 21 and 14 for sealing the LED element are arranged.

[0377] When there is a space between the LED substrate and the diffusion member, a spacer can be disposed between the LED substrate and the diffusion member. The spacer can be the same as the spacer used in a general LED backlight.

[0378] In addition, as described above, when the size of the LED element is small, the LED element can be arranged at a high density, that is, the interval (pitch) between the LED elements can be reduced, so even if the distance between the LED substrate and the diffusion component is shortened, the brightness unevenness can be suppressed. In this way, when the distance between the LED substrate and the diffusion component is short, the sealing component can be arranged between the LED substrate and the diffusion component.

[0379] (1) Sealing parts

[0380] The sealing member disclosed in the present invention is a member that is disposed on the surface side of the LED substrate on the LED element side and seals the LED element. The sealing member has light transmittance and is disposed on the light emitting surface side of the LED substrate.

[0381] It should be noted that the terms “light transmissivity” and “transparency” in the sealing member may be transparent to a degree that does not hinder visibility of light from the LED element.

[0382] The material contained in the sealing member of the present disclosure is not particularly limited as long as it is a material capable of sealing the LED element, and examples thereof include thermosetting resins, photocurable resins, thermoplastic resins, and the like.

[0383] Among them, thermoplastic resins are preferred. The reason why thermoplastic resins are preferred is described in the above-mentioned section "B. Laminated body", and therefore the description here is omitted.

[0384] The thermoplastic resin used for the sealing member of the present disclosure is the same as the thermoplastic resin described in the above-mentioned section "B. Laminated body 2. Sealing material sheet".

[0385] As the thermosetting resin used for the sealing member of the present disclosure, thermosetting resins generally used for sealing members of LED backlights can be adopted, and examples thereof include silicone-based resins and epoxy-based resins.

[0386] As the photocurable resin used for the sealing member of the present disclosure, a photocurable resin generally used for a sealing member of an LED backlight can be adopted.

[0387] Regarding the sealing component of the present disclosure, for example Fig.19 As shown, the sealing member 21 may be a single-layer member composed of a single resin layer. Fig.21 As shown, the sealing member 21 may also be a laminated resin layer (in Fig.21 For example, Fig.21 As shown, the sealing member 21 can be made into a three-layer structure of the surface layer 22a, the core layer 23 and the surface layer 22b.

[0388] It should be noted that the structure of the sealing member may be the same as the structure of the sealing material sheet in the above-mentioned laminate.

[0389] In the present disclosure, the sealing member is preferably a member formed using a sealing material sheet, wherein the sealing material sheet is composed of a sealing material composition containing a thermoplastic resin. It should be noted that the sealing material composition may be the same as the sealing material composition used for the sealing material sheet in the above-mentioned laminate.

[0390] The details of the sealing member may be the same as those described in the above-mentioned section "B. Laminated body 2. Sealing material sheet".

[0391] The thickness of the sealing member is appropriately set according to the distance between the above-mentioned diffusion member and the light emitting surface of the LED element of the LED substrate.

[0392] (2) Wavelength conversion component

[0393] The wavelength conversion component is usually arranged on the light-emitting surface side of the LED substrate and arranged at a position closer to the observer than the LED element. In the LED backlight of the present disclosure, the wavelength conversion component can be arranged on the surface side of the first layer side or the surface side of the second layer side of the diffusion component. In addition, when the sealing component is arranged, the arrangement of the wavelength conversion component can be, for example, as follows Fig. 22 As shown in (a) of FIG. 1 , a wavelength conversion member 41 may be arranged on the surface side of the second layer 3 of the diffusion member 1. Alternatively, Fig. 22 As shown in (b) of FIG. 1 , a wavelength conversion member 41 is disposed between the diffusion member 1 and the sealing member 21. The wavelength conversion member may be the same as the wavelength conversion member described in the above-mentioned section "A. Diffusing member".

[0394] (3) Optical components

[0395] In the LED backlight of the present disclosure, an optical component may be disposed on the surface side of the diffusion member on the second layer side. The optical component may be the same as the optical component described in the above-mentioned section "A. Diffuser member".

[0396] II. Second Embodiment of LED Backlight

[0397] The second embodiment of the LED backlight disclosed in the present invention is a device comprising: an LED substrate having a plurality of LED elements arranged on one surface side of a supporting substrate; and a diffusion component arranged on the surface side of the LED substrate on the side of the LED elements, the diffusion component having a transmission type diffraction grating or a microlens array, and a dielectric multilayer film in order from the side of the LED substrate. The LED backlight of this embodiment is a direct-type LED backlight.

[0398] The LED backlight of this embodiment can produce the same effects as those of the first embodiment of the LED backlight described above.

[0399] The diffusion member in this embodiment is the same as that described in the above section “A. Diffusion member II. Second embodiment.” The components constituting the diffusion member can be the same as those described in the above section “A. Diffusion member II. Second embodiment,” and thus descriptions thereof are omitted here.

[0400] The distance between the diffusion member and the light emitting surface of the LED element of the LED substrate can be the same as that in the first embodiment of the LED backlight described above.

[0401] The LED substrate in this embodiment may be the same as the LED substrate in the first embodiment of the LED backlight.

[0402] The other components in this embodiment may be the same as the other components in the first embodiment of the LED backlight described above.

[0403] D. Display device

[0404] The display device disclosed in the present invention is a device including a display panel and the above-mentioned LED backlight arranged on the back side of the display panel.

[0405] Fig.23 and Fig.24 is a schematic diagram showing an example of a display device of the present disclosure. Fig.23 and Fig.24 As shown in the example, the display device 30 or 50 includes: a display panel 31 or 51 ; and an LED backlight 10 disposed on the back surface of the display panel 31 or 51 .

[0406] According to the present disclosure, by having the above-mentioned LED backlight, it is possible to improve the in-plane uniformity of brightness while achieving thinness. In addition, it is also possible to reduce costs and power consumption. Therefore, a high-quality display device can be obtained.

[0407] Hereinafter, each configuration of the display device of the present disclosure will be described.

[0408] 1.LED backlight

[0409] The LED backlight of the present disclosure is the same as the components described in the above-mentioned “C. LED backlight.” The components constituting the LED backlight can be the same as those described in the above-mentioned “C. LED backlight,” and thus the description here is omitted.

[0410] 2. Display Panel

[0411] The display panel of the present disclosure is not particularly limited, and an example thereof may be a liquid crystal panel.

[0412] The present disclosure is not limited to the above-described embodiments. The above-described embodiments are merely examples, and any technical solution having substantially the same structure and exhibiting the same function and effect as the technical concept described in the claims of the present disclosure is included in the technical scope of the present disclosure.

[0413] Example

[0414] The present disclosure will be described in more detail with reference to examples below.

[0415] An optical simulation was performed to evaluate the in-plane uniformity of brightness. In the simulation, a ray tracing simulation was performed using LightTools manufactured by Synopsys.

[0416] [Test Example 1]

[0417] (condition)

[0418] Structure: A diffusion component is placed above the LED substrate.

[0419] · Diffuser: A diffuser composed of a first layer having light transmittance and light diffusivity and a second layer having incident angle dependence of reflectivity and transmittance.

[0420] Thickness of diffusion part: 0.2mm

[0421] ·Diffuser size: 4mm

[0422] Distance from the surface of the LED substrate to the diffusion component: 0.5mm

[0423] ·Transmittance of the first layer of the diffusion component: Total transmittance 98%

[0424] · Light diffusion of the first layer of the diffusion component: refracts incident light at 45°

[0425] ·Incident angle dependence of reflectance and transmittance of the second layer of the diffusion component: Refer to Fig.25

[0426] exist Fig.26 The simulation results are shown in .

[0427] [Test Example 2]

[0428] (condition)

[0429] Structure: A diffuser is placed above the LED substrate.

[0430] Diffusion component: diffuser plate containing particles

[0431] ·Light transmittance and light diffusion of the diffuser: total light transmittance 95%, haze 85%

[0432] Thickness of diffusion part: 0.5mm

[0433] ·Diffuser size: 4mm

[0434] Distance from the surface of the LED substrate to the diffusion component: 0.2mm

[0435] exist Fig. 27The simulation results are shown in .

[0436] [Test Example 3]

[0437] (condition)

[0438] Structure: A transmissive reflector and a diffusion component are sequentially arranged above the LED substrate.

[0439] Diffuser: Diffuser containing particles

[0440] ·Light transmittance and light diffusion of the diffuser: total light transmittance 95%, haze 85%

[0441] Transmissive reflective plate: A transmissive reflective plate was made by drilling through holes in the ultra-fine foamed light reflective plate "MCPET" (0.5 mm thick) manufactured by Furukawa Electric Co., Ltd. The through holes were designed to have a diameter of 0.25 mm just above the LED element, and the diameter of the through holes increases as they move away from the LED element in the surface direction. (See Fig.28 )

[0442] ·Thickness of transflective plate: 0.5mm

[0443] Thickness of diffuser plate: 2.4mm

[0444] · Size of diffuser and transflector: 24mm

[0445] Distance from the surface of the LED substrate to the transflective plate: 3.1 mm

[0446] exist Fig.29 The simulation results are shown in .

[0447] [Test Example 4]

[0448] (condition)

[0449] Structure: Optical components are placed above the LED substrate

[0450] ·Optical component: An optical component having only a second layer with incident angle dependence of reflectivity and transmittance

[0451] ·Thickness of optical component (2nd layer): 0.05mm

[0452] Size of optical part (2nd layer): 4mm

[0453] Distance from the surface of the LED substrate to the optical components: 0.5 mm

[0454] ·Incident angle dependence of reflectance and transmittance of optical components (layer 2): refer to Fig.25

[0455] exist Fig.30 The simulation results are shown in .

[0456] [evaluate]

[0457] The simulation results show that the in-plane uniformity of the illumination is improved in Test Example 1. On the other hand, in Test Example 2, the illumination is not uniform, although the distance between the LED substrate and the diffusion component is shorter than that in Test Example 1. Based on this result, it is confirmed that by setting the configuration of the diffusion component of the present disclosure, it is possible to achieve a thinner device while improving the in-plane uniformity of the brightness.

[0458] In addition, in Test Example 3, the in-plane uniformity of illumination was excellent, but the distance between the LED substrate and the transflective plate was longer than that in Test Example 1. It can be seen from Test Examples 2 and 3 that when using a conventional diffuser or transflective plate, in order to achieve uniform brightness, the distance between the LED substrate and the diffuser or transflective plate needs to be extended. Based on this result, it was confirmed that when a sealing member is arranged between the LED substrate and the diffuser or diffuser or transflective plate, by using the structure of the diffuser disclosed in the present invention, it is possible to achieve thinness and weight reduction while improving the in-plane uniformity of brightness.

[0459] In Test Example 1, the diameter of the white portion in the illuminance distribution was larger than that in Test Example 4. From this result, it was confirmed that the in-plane uniformity of the luminance was improved by using the structure of the diffusion member of the present disclosure.

[0460] Description of symbols

[0461] 1…Diffuser

[0462] 2…1st floor

[0463] 3…Layer 2

[0464] 10…LED backlight

[0465] 11…LED substrate

[0466] 12...Support base plate

[0467] 13…LED components

[0468] 14, 21… Sealing parts

[0469] 21a…Sealing material sheet

[0470] 15…Reflection layer

[0471] 30, 50…Display device

[0472] 31, 51…Display panel

[0473] 40…Laminated body

[0474] 60...Diffusion component set

[0475] 61…Part 1

[0476] 62…Part 2

Claims

1. A laminated component, wherein: The laminated component has: A sealing material sheet, which is arranged between the LED substrate and the diffusion component of an LED backlight having an LED substrate and a diffusion component, and is used to seal the LED element, wherein the LED substrate has a supporting substrate and the LED element arranged on one surface side of the supporting substrate; and The first layer is disposed on one surface side of the sealing material sheet and has light transmittance and light diffusivity. The first layer is arranged in a pattern on one side of the sealing material sheet. The sealing material sheet is composed of a sealing material composition containing an olefin-based resin.

2. The laminate component according to claim 1, wherein The first layer is a diffusing agent-containing resin film having a resin and a diffusing agent contained in the resin.

3. The laminated component according to claim 1, wherein A second layer is disposed on a surface of the first layer opposite to the sealing material sheet, The second layer is a layer whose reflectivity increases as the absolute value of the incident angle of light relative to the surface of the second layer on the first layer side decreases, and whose transmittance increases as the absolute value of the incident angle of light relative to the surface of the second layer on the first layer side increases.

4. The laminate component according to claim 3, wherein The light is red light.

5. The laminated component according to claim 3, wherein The light is green light.

6. The laminate component according to any one of claims 3 to 5, wherein: A wavelength conversion member is disposed on the surface side of the second layer opposite to the sealing material sheet or on the surface side of the first layer close to the sealing material sheet. The wavelength conversion component has quantum dots as phosphors.

7. An LED backlight source, wherein: The LED backlight source has: An LED substrate having a supporting substrate and an LED element arranged on one surface side of the supporting substrate; and The laminated component according to any one of claims 3 to 6, The sealing material sheet of the stacking component and the LED elements of the LED substrate are stacked so as to face each other.

8. A display device, wherein: The display device comprises: display panel; and The LED backlight source according to claim 7 is arranged on the back side of the display panel.

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