Light-emitting module and surface-emitting light source

Abstract

The present invention provides a light-emitting module and a surface-emitting light source, which can further reduce the thickness while suppressing uneven brightness. The light-emitting module comprises: a light guide plate (110A), which has an upper surface (110a) provided with a first hole portion (10A) and a lower surface (110b) on the side opposite to the upper surface; a light-emitting element (120), which is arranged on the lower surface side of the light guide plate opposite to the first hole portion; and a reflective resin layer (130); the first hole portion includes a first part (11A) and a second part (12A), the first part has a first side surface (11c) inclined relative to the upper surface, the second part has a second side surface (12c) inclined relative to the upper surface, the second side surface is located between the opening (12a) on the upper surface and the first side surface of the first part, and the reflective resin layer is located in the first part of the first hole portion.

Description

Technical Field

[0001] The present disclosure relates to a light emitting module and a surface emitting light source. Background Art

[0002] Patent document 1 below discloses a backlight device composed of a plurality of backlight units each having a light guide plate. The light guide plate of each backlight unit has a recessed portion in the central portion on the side opposite to the light emitting surface, and an LED is arranged in the recessed portion. The plurality of backlight units are arranged in such a manner that the exit surfaces of the light guide body become the same plane, thereby forming a backlight device as a whole. In the technology described in patent document 1, an optical sheet having a plurality of lens portions is arranged on the exit surface side of the light guide plate of each backlight unit, and a light reflecting layer having a plurality of opening portions is sandwiched between the lens portion and the light guide body, thereby improving the uniformity of light. In addition, patent document 1 discloses that the lens portion is enlarged as it moves away from the LED.

[0003] Patent document 2 below discloses an optical unit in which a plurality of optical elements are arranged on the upper surface side of a plurality of LEDs arranged on a substrate. In the optical unit, a plurality of LEDs are respectively located inside holes provided on the surface of the corresponding optical element on the side opposite to the exit surface. In the optical unit of patent document 2, a concave shape is formed directly above the LED on the exit surface of each optical element, and a lens array is formed in a manner surrounding the central portion of the exit surface where the concave shape is formed. Patent document 2 describes that a light diffusion portion, a reflection portion, or a light shielding portion can be provided inside the concave shape.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2009-150940

[0007] Patent Document 2: Japanese Patent Application Publication No. 2009-063684 Summary of the invention

[0008] It would be beneficial if the thickness of a light emitting module including a plurality of light sources represented by LEDs could be further reduced while suppressing uneven brightness. By reducing the thickness of the light emitting module, for example, a device including the light emitting module as a backlight can be further miniaturized.

[0009] A light-emitting module in one embodiment of the present disclosure comprises: a light guide plate having an upper surface provided with a first hole portion and a lower surface on the opposite side of the upper surface; a light-emitting element arranged on the lower surface side of the light guide plate opposite to the first hole portion; and a reflective resin layer; the first hole portion includes a first part and a second part, the first part has a first side surface inclined relative to the upper surface, the second part has a second side surface inclined relative to the upper surface, the second side surface is located between the opening on the upper surface and the first side surface of the first part, and the reflective resin layer is located in the first part of the first hole portion.

[0010] In one embodiment, it may also be:

[0011] The refractive index of the interior of the second portion of the first hole is lower than the refractive index of the reflective resin layer.

[0012] In one embodiment, it may also be:

[0013] The first portion of the first hole further has a bottom surface connected to the first side surface.

[0014] In one embodiment, it may also be:

[0015] An inclination of the first side surface relative to the upper surface is gentler than an inclination of the second side surface relative to the upper surface.

[0016] In one embodiment, it may also be:

[0017] The second side surface has a curved shape in a cross section perpendicular to the upper surface.

[0018] In one embodiment, it may also be:

[0019] The lower surface of the light guide plate has a second hole portion at a position opposite to the first hole portion.

[0020] The light emitting element is located inside the second hole in a plan view.

[0021] In one embodiment, it may also be:

[0022] The light emitting module further includes a wavelength conversion member located inside the second hole and between the light emitting element and the light guide plate.

[0023] In one embodiment, it may also be:

[0024] The light emitting element is located inside the first hole in a plan view.

[0025] The light emitting module further includes a wavelength conversion member located between the light emitting element and the light guide plate.

[0026] In one embodiment, it may also be:

[0027] The light emitting module further includes a wavelength conversion sheet located on or above the upper surface of the light guide plate.

[0028] In one embodiment, it may also be:

[0029] The light emitting element has an electrode on a side opposite to the light guide plate.

[0030] The light emitting module further includes a light reflecting member covering at least a portion of the lower surface of the light guide plate.

[0031] In one embodiment, it may also be:

[0032] The light emitting module further includes a wiring layer located on the lower surface side of the light reflecting member and electrically connected to the electrode.

[0033] In one embodiment, it may also be:

[0034] The light reflecting member includes a wall portion protruding from the lower surface side toward the upper surface side, and the wall portion includes an inclined surface surrounding the light emitting element.

[0035] A surface-emitting light source according to one embodiment of the present disclosure includes a plurality of light-emitting modules, wherein the light-emitting modules are the light-emitting modules described in any one of the above items.

[0036] The plurality of light emitting modules are arranged two-dimensionally.

[0037] According to at least any one of the embodiments of the present disclosure, a light emitting module that is thin and has improved light uniformity and a surface emitting light source having the light emitting module can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a schematic perspective view showing an exemplary structure of a surface-emitting light source according to an embodiment of the present disclosure.

[0039] Figure 2 is a schematic representation of Figure 1 The diagram shows a schematic cross section of an example of a light emitting module and an exemplary appearance viewed from the upper surface side of a light guide plate.

[0040] Figure 3 It is a magnified representation Figure 2 Schematic enlarged view of the light-emitting element and its surroundings.

[0041] Figure 4This is a schematic enlarged view of the vicinity of the first hole portion as viewed from the normal direction of the upper surface of the light guide plate, and is a view showing another example of the shape of the reflective resin layer.

[0042] Figure 5 This is a schematic enlarged view of the vicinity of the first hole portion as viewed from the normal direction of the upper surface of the light guide plate, and is a view showing still another example of the shape of the reflective resin layer.

[0043] Figure 6 This is a schematic plan view showing another example of the appearance of the light emitting module when viewed from the normal direction of the upper surface of the light guide plate.

[0044] Figure 7 It means that Figure 1 The schematic cross-sectional view shows a state where a surface-emitting light source is connected to a wiring substrate.

[0045] Figure 8 This is a diagram showing an example of a wiring pattern of a wiring layer formed on the surface-emitting light source side.

[0046] Fig. 9 It means to arrange multiple Figure 1 A schematic top view of an example of a surface-emitting light source is shown.

[0047] Fig.10 It means that Fig. 9 The illustrated schematic top view is of a structure in which the set of multiple surface-emitting light sources is further arranged in 2 rows and 2 columns.

[0048] Fig.11 1 is a schematic cross-sectional view showing a light emitting module according to another embodiment of the present disclosure.

[0049] Fig.12 It is a diagram showing a light emitting module according to still another embodiment of the present disclosure.

[0050] Fig.13 It is a diagram showing a light emitting module according to still another embodiment of the present disclosure.

[0051] Fig.14 It is a schematic cross-sectional view showing a light emitting module according to still another embodiment of the present disclosure.

[0052] Fig.15 It is a schematic cross-sectional view showing a light emitting module according to still another embodiment of the present disclosure.

[0053] Fig.16 It indicates the direction of the normal line observed from the upper surface of the light guide plate. Fig.15 The light emitting module shown is a schematic top view of an exemplary appearance.

[0054] Fig.17 This is a schematic plan view showing another example of a light guide plate having a plurality of convex portions on the upper surface.

[0055] Fig.18 This is a schematic plan view showing still another example of a light guide plate having a plurality of protrusions on the upper surface.

[0056] Fig.19 The diagram shows the appearance of a sample of an embodiment in which a diffusion sheet, a first prism sheet, and a second prism sheet are placed on the upper surface side of a light guide plate, when a light emitting element is turned on and the sample is observed from the upper surface side of the light guide plate.

[0057] Fig. 20 The diagram shows the appearance of a sample of a comparative example in which a diffusion sheet, a first prism sheet, and a second prism sheet are placed on the upper surface side of a light guide plate, when a light emitting element is turned on and the sample is observed from the upper surface side of the light guide plate.

[0058] Description of Reference Numerals

[0059] 10, 10A~10C First hole

[0060] 10a Opening of the first hole

[0061] 11A, 11B First portion of the first hole

[0062] 11b Bottom of the first part

[0063] 11c First side surface of the first hole portion

[0064] 12A Second part of the first hole

[0065] 12a Opening of the second part

[0066] 12c Second side of the second part

[0067] 20 Second hole

[0068] 100, 100A ~ 100H light emitting module

[0069] 100K, 100N, 100P light emitting module

[0070] 100U, 100T luminous body

[0071] 110A~110E Light guide plate

[0072] 110K Light Guide Plate

[0073] 110a Upper surface of the light guide plate

[0074] 110b Lower surface of light guide plate

[0075] 110d, 110e (plural) convex parts

[0076] 110f, 110g (plural) recesses

[0077] 111A, 111B, 111F Area 1

[0078] 111Ba The outer area of ​​the first area

[0079] 111Bb Inner area of ​​the first area

[0080] 112B, 112D, 112F Second Area

[0081] 120 Light emitting element

[0082] 124 Electrode of light-emitting element

[0083] 130 reflective resin layer

[0084] 140, 170 Light reflecting parts

[0085] 140s Inclined surface

[0086] 150, 150A wavelength conversion components

[0087] 160, 190 Joint parts

[0088] 180 Wiring Layer

[0089] 200 Surface emitting light sources

[0090] 210 Light guide plate

[0091] 240 Light reflecting parts

[0092] 250 Driver

[0093] 260 Wiring substrate

[0094] 320 Translucent Parts

[0095] 350 Wavelength Converter

[0096] 300, 400 surface emitting light source DETAILED DESCRIPTION

[0097] Hereinafter, the embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. The following embodiments are merely examples, and the light-emitting module of the present disclosure is not limited to the following embodiments. For example, the numerical values, shapes, materials, steps, and the order of the steps shown in the following embodiments are merely examples, and various changes can be made as long as no technical contradictions occur. The embodiments described below are merely examples, and various combinations can be made as long as no technical contradictions occur.

[0098] The sizes and shapes of the components shown in the drawings may be exaggerated for ease of understanding and may not reflect the actual size and shape of the light emitting module and the size relationship between the components. In addition, in order to avoid excessive complexity of the drawings, some elements may be omitted.

[0099] In the following description, the components having substantially the same function are represented by the same reference numerals, and the description is omitted. In the following description, it is possible to use terms indicating specific directions or positions (for example, "upper", "lower", "right", "left" and other terms containing these terms). However, these terms are used only for the sake of ease of understanding, and the relative directions or positions in the referenced drawings are used. If the relationship between the relative directions or positions defined by the terms such as "upper" and "lower" in the referenced drawings is the same, then the drawings, actual products, manufacturing devices, etc. outside the present disclosure may not be configured the same as the referenced drawings. In the present disclosure, the so-called "parallel" includes the situation where two straight lines, edges, surfaces, etc. are in the range of about 0° to ±5°, unless otherwise specified. In addition, in the present disclosure, the so-called "vertical" or "orthogonal" includes the situation where two straight lines, edges, surfaces, etc. are in the range of about 90° to ±5°, unless otherwise specified.

[0100] <Implementation Method of Surface Emitting Light Source>

[0101] Figure 1 This figure shows an exemplary structure of a surface-emitting light source according to an embodiment of the present disclosure. Figure 1 The surface emitting light source 200 shown includes: a light guide plate 210 having an upper surface 210a; and a layered light reflecting member 240 located below the light guide plate 210. Figure 1 In the figure, for convenience of explanation, arrows indicating the X direction, Y direction, and Z direction orthogonal to each other are shown together. In other drawings of the present disclosure, arrows indicating these directions are also shown.

[0102] The surface emitting light source 200 is in the shape of a plate as a whole. Typically, the upper surface 210a of the light guide plate 210 constituting the light emitting surface of the surface emitting light source 200 has a rectangular shape. Here, the above-mentioned X direction and Y direction are respectively consistent with one and the other of the mutually orthogonal sides of the rectangular shape of the light guide plate 210. The length of one side of the rectangular shape of the upper surface 210a is, for example, in the range of more than 1 cm and less than 200 cm. In a typical embodiment of the present disclosure, one side of the rectangular shape of the upper surface 210a of the light guide plate 210 has a length of more than 20 mm and less than 25 mm. The longitudinal and lateral lengths of the rectangular shape of the upper surface 210a can be, for example, approximately 24.3 mm and 21.5 mm, respectively.

[0103] exist Figure 1In the illustrated structure, the surface-emitting light source 200 is a collection of a plurality of light-emitting modules 100, each of which includes at least one light-emitting element. Figure 1 As shown schematically, the surface light source 200 in this example includes a total of 16 light-emitting modules 100 arranged two-dimensionally. Here, these 16 light-emitting modules 100 are arranged in 4 rows and 4 columns. The number of light-emitting modules 100 included in the surface light source 200 and the arrangement of these light-emitting modules 100 are arbitrary and are not limited to Figure 1 The structure shown.

[0104] like Figure 1 As shown, each light emitting module 100 has a first hole portion 10, and the first hole portion 10 includes an opening located on the upper surface 210a of the light guide plate 210 in a portion thereof. As described later, the surface emitting light source 200 may have an optical sheet such as a diffusion sheet, a prism sheet, etc. located on the upper surface 210a side of the light guide plate 210 and covering these first holes 10. The number of diffusion sheets arranged on the upper surface 210a side of the light guide plate 210 may be one or more. Similarly, the number of prism sheets arranged on the upper surface 210a side of the light guide plate 210 may be one or more.

[0105] As described in detail later, the light-emitting elements of each light-emitting module 100 are arranged at a position approximately directly below the first hole portion 10. In this example, the light-emitting modules 100 are arranged in 4 rows and 4 columns, and correspondingly, the light-emitting elements are arranged in 4 rows and 4 columns along the X direction and the Y direction. The configuration interval of the light-emitting elements can be set to, for example, about 0.05 mm to about 20 mm, or it can be in the range of about 1 mm to about 10 mm. Here, the configuration interval of the light-emitting elements refers to the distance between the optical axes of the light-emitting elements. The light-emitting elements can be arranged at equal intervals or at unequal intervals. The configuration interval of the light-emitting elements can be the same or different between two different directions.

[0106] Figure 2 A light emitting module 100A is shown as an example of the light emitting module 100. Figure 2 In the figure, a cross section of the light emitting module 100A when cut perpendicularly to the upper surface 210a of the light guide plate 210 near the center of the light emitting module 100A and an exemplary appearance of the light emitting module 100A when observed perpendicularly to the upper surface 210a from the upper surface 210a side of the light guide plate 210 are schematically shown together.

[0107] The light emitting module 100A includes: a light guide plate 110A having an upper surface 110a provided with a first hole 10A and a lower surface 110b opposite to the upper surface 110a; a light emitting element 120; and a reflective resin layer 130 located inside the first hole 10A. The light guide plate 110A is Figure 1The first hole portion 10A of the light guide plate 110A is Figure 1 One of the plurality of first hole portions 10 shown. It should be noted that the light guide plate 110A may be formed in the form of a single light guide plate that is continuous between two light emitting modules 100A adjacent to each other in the surface light emitting light source 200. However, by, for example, providing each light emitting module 100A with an independent light guide plate 110A, a clear boundary can be confirmed between the light guide plates 110A of the two light emitting modules 100A in the surface light emitting light source 200.

[0108] exist Figure 2 In the illustrated structure, the light emitting module 100A further includes a light reflecting member 140 located on the lower surface 110b side of the light guide plate 110A. The light reflecting member 140 is Figure 1 A portion of the light reflecting member 240 is shown. In this example, the light reflecting member 140 includes a layered base 140n and a wall 140w rising from the lower surface 110b side of the light guide plate 110A toward the upper surface 110a side. The wall 140w has an inclined surface 140s surrounding the light emitting element 120. Figure 2 The outermost rectangle B in the dotted rectangle shown in the lower half of the figure indicates the position of the inner edge of the wall portion 140w. Here, an example in which the inner edge of the wall portion 140w is a rectangular shape is shown, but the inner edge of the wall portion 140w may also be a circular shape, an elliptical shape, or other shapes. Similar to the light guide plate 110A, the light reflecting member 140 may be continuously formed across two adjacent light emitting modules 100A in the surface light emitting light source 200.

[0109] The first hole 10A of the light guide plate 110A is formed near the center of the upper surface 110a, and the first hole 10A includes: a first portion 11A having a first side surface 11c inclined relative to the upper surface 110a; and a second portion 12A having a second side surface 12c inclined relative to the upper surface 110a. As shown in the figure, the second side surface 12c of the second portion 12A is a portion located between the opening 12a on the upper surface 110a of the light guide plate 110A and the first side surface 11c of the first portion 11A, among one or more side surfaces defining the shape of the first hole 10A. The magnitude of the inclination of the first side surface 11c with respect to the upper surface 110a is different from the magnitude of the inclination of the second side surface 12c with respect to the upper surface 110a. In this example, the first portion 11A of the first hole 10A has a substantially inverted cone shape, and the second portion 12A has an inverted truncated cone shape.

[0110] In the light emitting module 100A, the light emitting element 120 is disposed on the lower surface 110b side of the light guide plate 110A so as to face the first hole portion 10A provided on the upper surface 110a of the light guide plate 110A. Figure 2In the example shown, the second hole 20 is provided on the lower surface 110b of the light guide plate 110A, and the light emitting element 120 is located inside the second hole 20 in a plan view. The optical axis of the light emitting element 120 substantially coincides with the center of the first hole 10A.

[0111] As described above, the reflective resin layer 130 of each light emitting module 100A is located inside the first hole 10A. In this embodiment, the reflective resin layer 130 is located in the first portion 11A of the first hole 10A closer to the light emitting element 120. In this example, the reflective resin layer 130 is formed inside the first hole 10A so as to occupy the entire first portion 11A.

[0112] As described later, the reflective resin layer 130 is formed of a light-reflective material. By providing the first hole portion 10A at a position opposite to the light-emitting element 120 of the light guide plate 110A, the light emitted from the light-emitting element 120 can be reflected at the position of the side surface that defines the shape of the first hole portion 10A. In particular, in the embodiment of the present disclosure, since the first hole portion 10A including the first portion 11A having the first side surface 11c and the second portion 12A having the second side surface 12c is provided on the upper surface 110a side of the light guide plate 110A, the first side surface 11c and the second side surface 12c, which are different in inclination relative to the upper surface 110a, can be used as a reflection surface, so that the light from the light-emitting element 120 can be more effectively diffused in the plane of the light guide plate 110A. In addition, since the reflective resin layer 130 is arranged in a manner opposite to the light-emitting element 120, it is possible to suppress the brightness directly above the light-emitting element 120 on the upper surface 110a of the light guide plate 110A from being extremely high compared to other areas. Here, since the reflective resin layer 130 is selectively formed inside the first portion 11A in the first hole 10A, it is possible to avoid the brightness directly above the light emitting element 120 from being reduced more than necessary. As a result, the overall thickness of the light emitting module 100A can be reduced while obtaining light with further improved uniformity.

[0113] Hereinafter, each component of the light emitting module 100A will be described in more detail.

[0114] [Light guide plate 110A]

[0115] The light guide plate 110A has a function of diffusing the light from the light emitting element 120 and emitting the light from the upper surface 110a. In the present embodiment, the upper surfaces 110a of the plurality of light guide plates 110A collectively constitute the light emitting surface of the surface emitting light source 200.

[0116] The light guide plate 110A is a roughly plate-shaped component formed of thermoplastic resins such as acrylic, polycarbonate, cyclic polyolefin, polyethylene terephthalate, polyester, thermosetting resins such as epoxy, silicone, or glass, and has light transmittance. Among these materials, polycarbonate is particularly cheap and can obtain high transparency. It should be noted that the terms "light transmittance" and "light transmissive" in this specification should be interpreted as also including the situation of showing diffusion relative to the incident light, and are not limited to "transparent". The light guide plate 110A can also have a light diffusion function, for example, by dispersing a material having a refractive index different from that of the base material.

[0117] The first hole portion 10A provided on the upper surface 110a of the light guide plate 110A has the function of reflecting the light emitted from the light emitting element 120 and introduced from the lower surface 110b side of the light guide plate 110A and diffusing it in the plane of the light guide plate 110A. By providing such a first hole portion 10A as a light diffusion structure on the light guide plate 110A, the brightness in the area other than directly above the light emitting element 120 in the upper surface 110a can be improved. That is, the uneven brightness at the upper surface of the light emitting module 100A can be suppressed, and the first hole portion 10A as a light diffusion structure contributes to the thinning of the light guide plate 110A. Typically, the thickness of the light guide plate 110A, that is, the distance from the lower surface 110b to the upper surface 110a, is about 0.1 mm or more and about 5 mm or less. According to the embodiment of the present disclosure, the thickness of the light guide plate 110A can also be set to a range of about 750μm.

[0118] Figure 3 Zoom in to show Figure 2 In the present embodiment, the first hole portion 10A includes a first portion 11A having a first side surface 11c and a second portion 12A having a second side surface 12c. As described above, the reflective resin layer 130 is located inside the first portion 11A. Figure 2 and Figure 3 In the example shown, the entire first portion 11A is filled with the reflective resin layer 130. For example, the entire first portion 11A is filled with the reflective resin layer 130 and the entire first side surface 11c is covered with the reflective resin layer 130, so that the light introduced into the interior of the light guide plate 110A and toward the first hole portion 10A at the position of the first side surface 11c can be effectively reflected.

[0119] like Figure 3As shown, in this example, the inclination of the first side surface 11c relative to the upper surface 110a of the light guide plate 110A is gentler than the inclination of the second side surface 12c relative to the upper surface 110a of the light guide plate 110A. According to such a shape of the first hole portion 10A, the area of ​​the first side surface 11c can be increased while suppressing the increase in the depth of the first hole portion 10A. Therefore, while avoiding the increase in the thickness of the light guide plate 110A, the light incident on the first side surface 11c can be diffused more effectively in the plane of the light guide plate 110A. Conversely, the inclination of the second side surface 12c relative to the upper surface 110a of the light guide plate 110A can also be made gentler than the inclination of the first side surface 11c relative to the upper surface 110a of the light guide plate 110A. According to such a structure, the volume of the second portion 12A can be expanded while avoiding the increase in the thickness of the light guide plate 110A, for example, the air layer in the first hole portion 10A can be expanded to a wider area. Therefore, more light is incident on the second side surface 12 c , and the light can be more effectively diffused within the plane of the light guide plate 110A.

[0120] exist Figure 3 In the illustrated structure, the first side surface 11c of the first portion 11A of the first hole portion 10A and the second side surface 12c of the second portion 12A are both curved in cross-sectional view. In this case, the inclination of the first side surface 11c and the second side surface 12c can be defined as follows.

[0121] From a cross-sectional perspective, the angle formed by a line segment connecting the lower end and the upper end of the first side surface 11c and a straight line parallel to the upper surface 110a of the light guide plate 110A is calculated as the size of the inclination of the first side surface 11c. The size of the inclination of the second side surface 12c is the same. From a cross-sectional perspective, the size of the inclination of the second side surface 12c can be calculated as the angle formed by a line segment connecting the lower end and the upper end of the second side surface 12c and a straight line parallel to the upper surface 110a of the light guide plate 110A. However, in this example, both the first side surface 11c and the second side surface 12c have a curved shape from a cross-sectional perspective. In such a case, the size of the inclination can be determined as shown below.

[0122] Here, the first portion 11A of the first hole portion 10A has a substantially inverted cone shape. Therefore, the first portion 11A has an opening 11a corresponding to the outer edge of the bottom surface of the inverted cone shape of the first portion 11A inside the first hole portion 10A. At this time, a line segment C1 is formed by connecting the portion of the first portion 11A that is the smallest distance from the lower surface 110b of the light guide plate 110A (in this example, the top of the inverted cone shape) and the opening 11a, and the angle θ1 formed by the line segment C1 and the straight line parallel to the upper surface 110a of the light guide plate 110A is set as the size of the inclination of the first side surface 11c. Similarly, as the size of the inclination of the second side surface 12c, the opening 11a of the first portion 11A and the opening 12a of the second portion 12A can be connected to form a line segment C2, and the angle θ2 formed by the line segment C2 and the straight line parallel to the upper surface 110a of the light guide plate 110A can be used.

[0123] Here, the shapes of the first side surface 11c and the second side surface 12c in the cross-sectional perspective are curved. However, the shapes of the first side surface 11c and the second side surface 12c in the cross-sectional perspective are not limited to curved, and may be curved and / or stepped shapes or straight lines. The shapes of the first side surface 11c and the second side surface 12c in the cross-sectional perspective do not necessarily have to be the same. If the shapes of the first side surface 11c and / or the second side surface 12c in the cross-sectional perspective are Figure 3 The exemplified curved shape, particularly the convex curved shape that bulges toward the inside of the first hole 10A, easily diffuses light to a position away from the center of the light guide plate 110A, and is advantageous in terms of obtaining uniform light on the upper surface 110a side.

[0124] On the other hand, in this example, the interior of the second portion 12A of the first hole portion 10A is not filled with resin or the like, and an air layer is formed. In other words, the interior of the second portion 12A has a lower refractive index than that of the first portion 11A. Therefore, in this example, the second side surface 12c of the second portion 12A is the interface between the air layer and the light guide plate 110A, and functions as a reflective surface for returning light introduced into the interior of the light guide plate 110A and directed toward the first hole portion 10A to the interior of the light guide plate 110A. That is, by utilizing the second side surface 12c of the second portion 12A, light incident at an angle close to vertical with respect to the upper surface 110a of the light guide plate 110A can be diffused toward the interior of the light guide plate 110A. If the material has a lower refractive index than the reflective resin layer 130, the second portion 12A can also be filled with such a material.

[0125] The specific shape of the first hole portion 10A is not limited to Figure 3The shape of the example. The specific structure of the first hole portion 10A as a light diffusion structure can be appropriately determined according to the shape and characteristics of the light-emitting element arranged on the lower surface 110b side of the light guide plate 110A. The shapes of the first part 11A and the second part 12A of the first hole portion 10A can be, for example, a cone, or a polygonal pyramid such as a quadrangular pyramid or a hexagonal pyramid, or a polygonal truncated pyramid. The depth of the first hole portion 10A is, for example, in the range of 300μm to 400μm. Among them, the depth of the first part 11A can be, for example, in the range of 100μm to 200μm. The diameter of the opening 11a of the first part 11A can be, for example, about 2mm, and the diameter of the opening 12a of the second part 12A can be, for example, about 3mm.

[0126] The light guide plate 110A may be a single layer or may have a stacked structure including a plurality of light-transmitting layers. In the case of stacking a plurality of light-transmitting layers, a layer having a refractive index different from other layers such as an air layer may be sandwiched between any of the layers. By sandwiching an air layer between any of the layers in the stacked structure, for example, it is easy to further diffuse the light from the light-emitting element 120, and the brightness unevenness can be further reduced.

[0127] In the example shown in the figure, the light guide plate 110A has a second hole portion 20 at a position opposite to the first hole portion 10A on the lower surface 110b side. The joining member 190 and the light emitting body 100U including the light emitting element 120 are located inside the second hole portion 20. The light emitting body 100U includes a plate-shaped wavelength conversion member 150, a joining member 160, and a second light reflecting member 170 in addition to the light emitting element 120. The light emitting body 100U is joined to the position of the second hole portion 20 of the light guide plate 110A by the joining member 190.

[0128] from Figure 2 It can be understood that the second hole portion 20 has, for example, a quadrangular pyramid shape. Typically, the center of the second hole portion 20 located on the lower surface 110b side of the light guide plate 110A is substantially consistent with the center of the first hole portion 10A located on the upper surface 110a side. The length of the opening 20a of the second hole portion 20 formed on the lower surface 110b of the light guide plate 110A along the diagonal direction of the rectangle can be set to, for example, 0.05 mm or more and 10 mm or less, preferably 0.1 mm or more and 1 mm or less.

[0129] When the second hole portion 20 is rectangular in plan view, the second hole portion 20 may be as follows: Figure 2 As shown in FIG. 1 , the rectangular shape is formed on the lower surface 110b of the light guide plate 110A in such a manner that one side of the rectangular shape is parallel to one side of the rectangular shape of the light guide plate 110A. Figure 6 As shown, the second hole portion 20 may be formed on the lower surface 110 b of the light guide plate 110A in a manner inclined with respect to one side of the rectangular shape of the light guide plate 110A.

[0130] Figure 6 The example in which the rectangular shape of the opening 20a of the second hole portion 20 is inclined by 45° relative to the rectangular shape of the light guide plate 110A is shown. Figure 6 In the example shown, the second hole portion 20 is formed in such a manner that the sides of the rectangular shape of the opening 20a are substantially parallel to the diagonal lines of the rectangular shape of the light guide plate 110A, so that the four side surfaces of the second hole portion 20 are opposite to the corners of the rectangular shape of the light guide plate 110A. That is, the distance from the side surface of the second hole portion 20 to the corner of the light guide plate 110A can be increased, and the distance from the corner of the quadrangular pyramid shape of the second hole portion 20 to the side surface of the light guide plate 110A can be decreased. According to the optical characteristics of the light emitting body 100U, such a structure can further suppress uneven brightness.

[0131] As for the shape of the second hole portion 20 in a plan view, in addition to Figure 2 and Figure 6 In addition to the rectangular shape shown, a circular shape may also be adopted. It is not necessary for the embodiment of the present disclosure that the second hole portion 20 has an outer shape similar to the outer shape of the light guide plate 110A. The shape and size of the second hole portion 20 can be appropriately determined according to the required optical properties. For example, the second hole portion 20 can have a truncated cone shape, etc.

[0132] [Reflective resin layer 130]

[0133] Refer again Figure 3 As described above, the reflective resin layer 130 is located in the first portion 11A of the first hole portion 10A. It is not necessary for the entire first portion 11A to be filled with the reflective resin layer 130 in the embodiment of the present disclosure. The reflective resin layer 130 only needs to occupy a portion of the first portion 11A. For example, the reflective resin layer 130 may be formed in the first hole portion 10A in a manner that covers the first side surface 11c of the first portion 11A.

[0134] The reflective resin layer 130 is formed of a light reflective material such as a resin material in which a light reflective filler is dispersed. Here, in this specification, "reflectivity" and "light reflectivity" refer to a reflectivity of 60% or more at the peak wavelength of light emission of the light emitting element 120. It is more beneficial that the reflectivity of the reflective resin layer 130 at the peak wavelength of light emission of the light emitting element 120 is 70% or more, and it is further beneficial that the reflectivity of the reflective resin layer 130 at the peak wavelength of light emission of the light emitting element 120 is 80% or more.

[0135] As the base material of the resin material for forming the reflective resin layer 130, silicone resin, phenolic resin, epoxy resin, BT resin, polyphthalamide (PPA), etc. can be used. As the light reflective filler, metal particles, or particles of inorganic or organic materials having a higher refractive index than the base material can be used. Examples of light reflective fillers are particles of titanium dioxide, silicon oxide, zirconium dioxide, potassium titanate, aluminum oxide, aluminum nitride, boron nitride, mullite, niobium oxide, barium sulfate, or particles of various rare earth oxides such as yttrium oxide and gadolinium oxide. It is more beneficial for the reflective resin layer 130 to have a white color.

[0136] The distribution of the light reflective filler in the reflective resin layer 130 may be substantially constant, or may have a bias or gradient in the reflective resin layer 130. For example, by depositing the filler or separating it from the base material before the base material is hardened in the process of forming the reflective resin layer 130, the distribution of the light reflective filler in the reflective resin layer 130 may be biased. Figure 4 As shown, the reflective resin layer 130 may have a first region 131 and a second region 132 having a relatively low concentration of fillers. Figure 4 In the example shown, the plurality of second regions 132 extend from the outer edge toward the center of the first hole portion 10A. Figure 5 As in the illustrated example, the reflective resin layer 130 has a plurality of island-shaped portions 133 near the opening 11 a of the first portion 11A.

[0137] The filler number density is defined as the number of fillers per unit area in a plan view. If the filler number density is relatively higher near the center of the reflective resin layer 130 than near the outer edge of the reflective resin layer 130, it is easier to suppress the brightness of the area directly above the light emitting element 120 from becoming extremely high locally, which is beneficial. Figure 4 as well as Figure 5 In any of the examples shown, it can be said that the number density of the filler is relatively higher near the center of the reflective resin layer 130 than near the outer edge of the reflective resin layer 130 .

[0138] By disposing the reflective resin layer 130 above the light emitting element 120, the reflective resin layer 130 can reflect the light emitted from the light emitting element 120 and traveling toward the upper surface 110a of the light guide plate 110A near the center of the light guide plate 110A. Therefore, the light emitted from the light emitting element 120 can be effectively diffused within the surface of the light guide plate 110A. In addition, it is possible to suppress the brightness of the area directly above the light emitting element 120 in the upper surface 110a of the light guide plate 110A from being extremely high locally. However, it is not necessary for the reflective resin layer 130 to completely block the light from the light emitting element 120. This means that the reflective resin layer 130 may also have a semi-transmissive property that allows a portion of the light from the light emitting element 120 to pass through.

[0139] Here, the upper surface 130a of the reflective resin layer 130 is a substantially flat surface. However, the shape of the upper surface 130a of the reflective resin layer 130 is not limited to this example, and may be a convex shape protruding toward the side opposite to the light emitting element 120, or a concave shape recessed toward the light emitting element 120. In particular, if the upper surface 130a of the reflective resin layer 130 is a convex shape protruding toward the side opposite to the light emitting element 120, the thickness near the center of the reflective resin layer 130 becomes relatively large when the position of the opening 11a of the first portion 11A is used as a reference, and as a result, the brightness of the area directly above the light emitting element 120 can be more effectively suppressed from being extremely high locally.

[0140] exist Figure 3 In the example shown, the reflective resin layer 130 is filled from the deepest part of the second part 12A to the position of the opening 11a. In other words, in this example, the reflective resin layer 130 is not formed to a higher position inside the first hole portion 10A beyond the position of the opening 11a. However, it is not necessary for the embodiment of the present disclosure that the reflective resin layer 130 does not include a portion that exceeds the position of the opening 11a. The reflective resin layer 130 may be allowed to include a portion located inside the first part 11A of the first hole portion 10A. It should be noted that if the inclination of the first side surface 11c is gentler than the inclination of the second side surface 12c, even if a portion of the reflective resin layer 130 reaches the inside of the first part 11A, it is easy to suppress the increase in the area occupied by the reflective resin layer 130 in the first hole portion 10A when viewed from above. That is, it is easy to avoid unnecessary excessive reduction in brightness near the first hole portion 10A.

[0141] [Light emitting element 120]

[0142] A typical example of the light emitting element 120 is an LED. Figure 3In the illustrated structure, the light emitting element 120 has an element body 122 and an electrode 124 located on the side opposite to the upper surface 120a of the light emitting element 120. The element body 122 includes, for example, a support substrate such as sapphire or gallium nitride and a semiconductor stacking structure on the support substrate. The semiconductor stacking structure includes an n-type semiconductor layer and a p-type semiconductor layer and an active layer sandwiched therebetween. The semiconductor stacking structure may include a nitride semiconductor (In x Al y Ga 1-x-y N, 0≤x, 0≤y, x+y≤1). In this example, the upper surface 120a of the light emitting element 120 coincides with the upper surface of the element body 122. The electrode 124 includes a group of a positive electrode and a negative electrode, and has a function of supplying a predetermined current to the semiconductor stack structure.

[0143] The plurality of light emitting elements 120 provided in the surface light source 200 may be elements emitting blue light or elements emitting white light. The plurality of light emitting elements 120 may include elements emitting light of different colors from each other. For example, the plurality of light emitting elements 120 may include elements emitting red light, elements emitting blue light, and elements emitting green light. Here, as the light emitting element 120, an LED emitting blue light is exemplified.

[0144] In this example, the light emitting element 120 in each light emitting module 100A is fixed to the lower surface side of the wavelength conversion component 150 by a bonding component 160. Typically, the shape of the light emitting element 120 when viewed from above is a rectangular shape. The length of one side of the rectangular shape of the light emitting element 120 is, for example, less than 1000 μm. The longitudinal and lateral dimensions of the rectangular shape of the light emitting element 120 may also be less than 500 μm. Light emitting elements with longitudinal and lateral dimensions of less than 500 μm are easy to purchase economically. Alternatively, the longitudinal and lateral dimensions of the rectangular shape of the light emitting element 120 may also be less than 200 μm. If the length of one side of the rectangular shape of the light emitting element 120 is small, it is beneficial to the expression of high-definition images, local dimming operations, etc. in the application of the backlight unit to the liquid crystal display device. In particular, since the area of ​​the upper surface of the light emitting element with both longitudinal and lateral dimensions of less than 250 μm is small, the amount of light emitted from the side of the light emitting element becomes relatively large. Therefore, it is easy to obtain a bat-wing-shaped light distribution characteristic. Here, the so-called bat-wing light distribution characteristic, in a broad sense, refers to a light distribution characteristic defined by a luminous intensity distribution with high luminous intensity at an angle where the absolute value of the light distribution angle is greater than 0°, with the optical axis perpendicular to the upper surface of the light-emitting element being set to 0°.

[0145] [Wavelength conversion member 150]

[0146] exist Figure 3In the illustrated structure, the wavelength conversion component 150 is disposed inside the second hole 20 and between the light guide plate 110A and the light emitting element 120. In other words, the wavelength conversion component 150 is located above the light emitting element 120 and at the bottom of the second hole 20. Here, the so-called "bottom of the second hole 20" refers to the portion corresponding to the bottom of the second hole 20 when the lower surface 110b of the light guide plate 110A is facing upward. Thus, in this specification, the terms "bottom" and "bottom surface" are sometimes used for the light emitting module, regardless of the posture shown in the drawings. When the light emitting module 100A is set Figure 3 In the illustrated posture, the bottom of the second hole 20 can also be said to be the top portion of the dome-shaped structure formed on the lower surface 110 b side of the light guide plate 110A.

[0147] The wavelength conversion component 150 absorbs at least a portion of the light emitted from the light emitting element 120, and emits light of a wavelength different from the wavelength of the light from the light emitting element 120. For example, the wavelength conversion component 150 converts a portion of the blue light from the light emitting element 120 into yellow light. According to such a structure, white light is obtained by mixing the blue light passing through the wavelength conversion component 150 and the yellow light emitted from the wavelength conversion component 150. Figure 3 In the illustrated structure, the light emitted from the light emitting element 120 is basically introduced into the interior of the light guide plate 110A via the wavelength conversion component 150. Therefore, the mixed color light is diffused inside the light guide plate 110A, and white light, for example, with suppressed brightness unevenness, can be taken out from the upper surface 110a of the light guide plate 110A. The embodiment of the present disclosure is more conducive to the uniformity of light than the case where the wavelength is converted after the light is diffused into the light guide plate.

[0148] Typically, the wavelength conversion component 150 is a component in which particles of a phosphor are dispersed in a resin. As the resin in which the particles of the phosphor and the like are dispersed, silicone resin, modified silicone resin, epoxy resin, modified epoxy resin, urea resin, phenolic resin, acrylic resin, polyurethane resin or fluororesin, or a resin containing two or more of these resins can be used. From the perspective of effectively introducing light to the light guide plate 110A, it is beneficial for the base material of the wavelength conversion component 150 to have a lower refractive index than the material of the light guide plate 110A. By dispersing a material having a different refractive index from that of the base material in the material of the wavelength conversion component 150, a light diffusion function can also be imparted to the wavelength conversion component 150. For example, particles of titanium dioxide, silicon oxide, etc. can be dispersed in the base material of the wavelength conversion component 150.

[0149] The phosphor can be a known material. Examples of the phosphor include fluoride phosphors such as YAG phosphors and KSF phosphors, nitride phosphors such as CASN, and β-sialon phosphors. YAG phosphors are examples of wavelength conversion materials that convert blue light into yellow light, KSF phosphors and CASN are examples of wavelength conversion materials that convert blue light into red light, and β-sialon phosphors are examples of wavelength conversion materials that convert blue light into green light. The phosphor can be a quantum dot phosphor.

[0150] It is not necessary for the phosphor included in the wavelength conversion component 150 to be the same in the multiple light-emitting modules 100 included in the same surface-emitting light source 200. The phosphor dispersed in the base material of the wavelength conversion component 150 may be different between the multiple light-emitting modules 100. A wavelength conversion component that converts incident blue light into yellow light may be arranged in a part of the second hole portions 20 of the multiple second hole portions 20 provided in the light guide plate 210 of the surface-emitting light source 200, and a wavelength conversion component that converts incident blue light into green light may be arranged in another part of the second hole portions 20. Furthermore, a wavelength conversion component that converts incident blue light into red light may be arranged in the remaining second hole portions 20.

[0151] [Jointing member 160]

[0152] The bonding member 160 is a light-transmitting member that covers at least a portion of the side surface of the light-emitting element 120. Figure 3 As schematically shown, typically, the bonding member 160 has a layered portion located between the upper surface 120 a of the light emitting element 120 and the wavelength conversion member 150 .

[0153] As a material of the bonding member 160, a resin composition containing a transparent resin material as a base material can be used. The bonding member 160 has a transmittance of, for example, 60% or more with respect to light having a peak emission wavelength of the light emitting element 120. From the viewpoint of effective use of light, it is beneficial for the bonding member 160 to have a transmittance of 70% or more at the peak emission wavelength of the light emitting element 120, and it is more beneficial for the bonding member 160 to have a transmittance of 80% or more at the peak emission wavelength of the light emitting element 120.

[0154] Typical examples of the base material of the bonding member 160 are thermosetting resins such as epoxy resins and silicone resins. As the base material of the bonding member 160, silicone resin, silicone-modified resin, epoxy resin, phenolic resin, polycarbonate resin, acrylic resin, polymethylpentene resin or polynorbornene resin, or a material containing two or more of them can be used. The bonding member 160 typically has a refractive index lower than that of the light guide plate 110A. The bonding member 160 may also have a light diffusion function by, for example, dispersing a material having a refractive index different from that of the base material.

[0155] As described above, the bonding member 160 covers at least a portion of the side surface of the light emitting element 120. In addition, the bonding member 160 has an outer surface that serves as an interface between it and the light reflecting member 170 described later. Light emitted from the side surface of the light emitting element 120 and incident on the bonding member 160 is reflected toward the upper side of the light emitting element 120 at a position on the outer surface of the bonding member 160. The shape of the outer surface of the bonding member 160 in the cross-sectional view is not limited to Figure 3 The outer surface of the bonding member 160 in a cross-sectional view may be in the shape of a broken line, a curved line protruding toward the light emitting element 120, a curved line protruding away from the light emitting element 120, or the like.

[0156] [(Second) Light Reflecting Member 170]

[0157] The light reflecting member 170 is a member having light reflectivity and is located on the lower surface side of the wavelength converting member 150 (the side opposite to the light guide plate 110A). Figure 3 As shown, the light reflecting member 170 covers the outer surface of the bonding member 160, the portion of the side surface of the light emitting element 120 that is not covered by the bonding member 160, and the region of the lower surface of the light emitting element 120 that is located on the side opposite to the upper surface 120a except the electrode 124. The light reflecting member 170 covers the side surface of the electrode 124, while the lower surface of the electrode 124 is exposed from the lower surface of the light reflecting member 170.

[0158] As the material of the light reflecting member 170, the same material as the material of the reflective resin layer 130 can be used. For example, the material of the light reflecting member 170 and the material of the reflective resin layer 130 can be the same. By covering the area of ​​the lower surface of the light emitting element 120 except the electrode 124 with the light reflecting member 170, it is possible to suppress the leakage of light to the side opposite to the upper surface 110a of the light plate 110A. In addition, by covering the side surface of the light emitting element 120 with the light reflecting member 170, the light from the light emitting element 120 can be concentrated upward, and the light can be effectively introduced to the wavelength conversion member 150.

[0159] [Second Engagement Member 190]

[0160] As described above, the light emitting body 100U is disposed at the bottom of the second hole 20 by using the second bonding member 190. Figure 3 As shown, at least a portion of the second bonding member 190 is located inside the second hole portion 20. The second bonding member 190 may have a portion located between the bottom of the second hole portion 20 and the wavelength conversion member 150. Figure 3As shown, the second bonding member 190 may have a portion that is raised further toward a side opposite to the upper surface 110 a of the light guide plate 110A than the lower surface 110 b of the light guide plate 110A.

[0161] The second bonding member 190 is formed of a resin composition including a transparent resin material as a base material, similar to the bonding member 160. The material of the second bonding member 190 may be different from or the same as that of the bonding member 160. Typically, the second bonding member 190 has a refractive index lower than that of the light guide plate 110A.

[0162] [Light reflecting member 140]

[0163] The light reflecting member 140 has light reflectivity and covers at least a portion of the lower surface 110b of the light guide plate 110A. Here, the light reflecting member 140 covers not only the lower surface 110b of the light guide plate 110A but also the second bonding member 190. As shown in this example, by covering the second bonding member 190 with the light reflecting member 140, light leakage from the second bonding member 190 to the lower surface 110b of the light guide plate 110A can be suppressed, thereby improving light output efficiency.

[0164] The light reflecting member 140 includes a wall portion in a part thereof, and as a result, an inclined surface 140s is formed in a part of the upper surface 140a of the light reflecting member 140 that faces the lower surface 110b of the light guide plate 110A. Figure 2 It can be understood that, typically, the inclined surface 140s surrounds the light emitting element 120 along the four sides of the rectangular shape of the upper surface 110a of the light guide plate 110A. The inclined surface 140s can function as a reflecting surface that reflects the incident light toward the upper surface 110a of the light guide plate 110A. Therefore, by arranging the light reflecting component 140 having the inclined surface 140s on the lower surface 110b side of the light guide plate 110A, the inclined surface 140s can be used to reflect the light toward the lower surface 110b side of the light guide plate 110A toward the upper surface 110a, and the light can be output more efficiently from the upper surface 110a. In addition, by arranging the inclined surface 140s on the peripheral portion of the light guide plate 110A, it is possible to avoid the brightness at the peripheral portion of the light guide plate 110A being relatively lower than that at the center portion.

[0165] The shape of the inclined surface 140s from a cross-sectional perspective may be Figure 2 The shape of the inclined surface 140s in the cross-sectional view is not limited thereto, and may include steps, bends, and the like.

[0166] It should be noted that the height of the wall surrounding the light emitting element 120 may be made different between the plurality of light emitting modules 100 included in one surface emitting light source 200 or in one light emitting module 100. For example, among the plurality of inclined surfaces 140s included in one surface emitting light source 200, the height of the inclined surface 140s located at the outermost periphery of the light guide plate 210 of the surface emitting light source 200 may be made greater than the height of the inclined surfaces 140s located at other parts of the light guide plate 210.

[0167] As the material of the light reflecting member 140, the same material as the material of the second light reflecting member 170 can be used. By making the material of the light reflecting member 140 the same as the material of the light reflecting member 170, the light reflecting member covering substantially the entire lower surface 110b of the light guide plate 110A can be formed integrally with the light reflecting material. By forming the light reflecting member 140 on the lower surface 110b side of the light guide plate 110A, effects such as reinforcement of the light guide plate 110A can also be expected.

[0168] [Wiring layer 180]

[0169] exist Figure 3 In the illustrated structure, the light emitting module 100A further includes a wiring layer 180 located on the lower surface 140b of the light reflecting member 140. The wiring layer 180 includes wiring electrically connected to the electrode 124 of the light emitting element 120. In this example, the wiring layer 180 is depicted as being located on the light reflecting member 170, but the wiring layer 180 may also include a portion located on the lower surface 140b of the light reflecting member 140.

[0170] Typically, the wiring layer 180 is a single-layer film or a laminated film made of a metal such as Cu. The wiring layer 180 is connected to a power source (not shown) or the like, and functions as a terminal for supplying a predetermined current to each light emitting element 120 .

[0171] By providing a wiring layer 180 on the lower surface 100b side of the light-emitting module 100A, the wiring layer 180 can be used to electrically connect multiple light-emitting elements 120 in, for example, a surface-emitting light source 200. That is, the light-emitting element 120 can be driven in units of, for example, a surface-emitting light source 200. As described later, by combining multiple surface-emitting light sources 200 to further construct a large surface-emitting light source, the surface-emitting light source can be made to perform local dimming operations. By providing a wiring layer 180 on the lower surface 100b side of the light-emitting module 100A and forming wiring on the side of the surface-emitting light source 200 including the multiple light-emitting elements 120, it is easy to connect to a power source or the like. That is, surface light emission can be simply obtained by connecting a power source or the like. Of course, the light-emitting element 120 can be driven in units of more than one light-emitting module 100A.

[0172] Figure 7200 is connected to the wiring substrate. Figure 7 As shown, the light emitting device of the present disclosure may have a wiring substrate 260. Figure 7 In the illustrated structure, the wiring substrate 260 includes an insulating substrate 265, a wiring layer 262 on the insulating substrate 265, and a plurality of through holes 264. The wiring layer 262 is provided on one main surface of the insulating substrate 265, and the through holes 264 are connected to the wiring layer 262. The wiring layer 262 is electrically connected to the surface light source 200 using the through holes 264 disposed inside the insulating substrate 265.

[0173] The wiring substrate 260 is located on the lower surface side of the surface emitting light source 200, that is, on the side opposite to the upper surface 210a of the light guide plate 210. The surface emitting light source 200 is mounted on the wiring substrate 260 by combining the wiring layer 180 with the wiring layer 262 of the wiring substrate 260 by welding or the like. According to the present embodiment, the wiring layer 180 connected to each light emitting element 120 can be arranged on the surface emitting light source 200 side, so there is no need to form a complicated wiring pattern on the wiring substrate 260 side, and the connection required for local dimming can be easily formed. Since the wiring layer 180 has a larger area than the lower surface of the electrode 124 of each light emitting element 120, it is relatively easy to form an electrical connection with the wiring layer 262. Alternatively, in the case where the light emitting module 100A does not have the wiring layer 180, for example, the electrode 124 of the light emitting element 120 can also be connected to the wiring layer 262 of the wiring substrate 260.

[0174] Figure 8 An example of a wiring pattern of the wiring layer 180 is shown. Figure 8 The four Figure 1 The example shown is that the surface-emitting light source 200 is connected to one driver 250 .

[0175] Each surface-emitting light source 200 may include a wiring layer 180. The wiring layer 180 in each surface-emitting light source 200 electrically connects the plurality of light-emitting modules 100A included in the surface-emitting light source 200. Figure 8 In the example shown, the wiring layer 180 in each surface-emitting light source 200 is connected in series with four light-emitting elements 120 , and the four groups of the series-connected light-emitting elements 120 are connected in parallel.

[0176] like Figure 8As shown, these wiring layers 180 can be connected to the drivers 250 for driving the light-emitting elements 120, respectively. The driver 250 can be arranged on a substrate (such as a wiring substrate 260) that supports the collection of surface-emitting light sources 200 and electrically connected to the wiring layer 180, or it can be arranged on a substrate different from the substrate that supports the collection of surface-emitting light sources 200 and electrically connected to the wiring layer 180. With such a circuit structure, local dimming can be performed in units of a surface-emitting light source 200 including 16 light-emitting elements 120. Of course, the connection of the wiring layer 180 to multiple light-emitting elements 120 is not limited to Figure 8 In the example shown, each light emitting module 100A in the surface light emitting light source 200 may be connected in a manner that each is independently driven. Alternatively, the light emitting modules 100A included in the surface light emitting light source 200 may be divided into a plurality of groups, and the plurality of light emitting elements 120 may be electrically connected in a manner that the light emitting elements 120 can be driven in units of the groups including the plurality of light emitting modules 100A.

[0177] As described above, according to the embodiment of the present disclosure, the reflection of light by the reflective resin layer 130 can suppress the extreme increase in brightness at the position directly above the light emitting element 120, while diffusing the light from the light emitting element 120 within the surface of the light guide plate 110A. Thus, a thin and uniform light can be provided. Figure 3 As in the described example, by interposing the wavelength conversion member 150 between the light emitting element 120 and the light guide plate 110A, the mixed color light can be diffused within the plane of the light guide plate 110A and then emitted from the upper surface 110a of the light guide plate 110A.

[0178] According to the embodiments of the present disclosure, for example, the thickness of the structure including the light reflecting member 140, in other words, the distance from the lower surface of the electrode 124 of the light emitting element 120 to the upper surface 110a of the light guide plate 110A can be reduced to, for example, 5 mm or less, 3 mm or less, or 1 mm or less. The distance from the lower surface of the electrode 124 of the light emitting element 120 to the upper surface 110a of the light guide plate 110A can be about 0.7 mm or more and 1.1 mm or less.

[0179] Fig. 9 The example in which a plurality of surface emitting light sources 200 are two-dimensionally arranged is shown. By two-dimensionally arranging a plurality of surface emitting light sources 200, a light emitting surface with a large area is obtained.

[0180] Fig. 9 The surface emitting light source 300 shown has multiple Figure 1 The surface emitting light source 200 is shown. Fig. 9This is an example in which the surface-emitting light sources 200 are arranged in 8 rows and 16 columns, and schematically shows the appearance of the two-dimensional arrangement of the surface-emitting light sources 200 as viewed from the upper surface 210 a side of the light guide plate 210 .

[0181] Typically, the light guide plates 210 of two adjacent surface light sources 200 in the row direction or column direction are in direct contact with each other. However, it is not necessary to form a two-dimensional arrangement in a manner that the light guide plates 210 of two adjacent surface light sources 200 are in direct contact with each other. A light guide structure that optically combines them with each other can also be sandwiched between two adjacent light guide plates 210. Such a light guide structure can be formed, for example, by applying a translucent adhesive to the side of the light guide plate 210 and then hardening the applied adhesive. Alternatively, a plurality of surface light sources 200 can be arranged two-dimensionally in a manner spaced apart from each other, and the area between two adjacent light guide plates 210 can be filled with a translucent resin material, and then the light guide structure can be formed by hardening the resin material. As the material of the light guide structure located between the light guide plates 210, the same material as the above-mentioned bonding member 160 can be used. As the base material of the light guide structure, it is beneficial if a material having a refractive index equal to or greater than that of the material of the light guide plate 210 can be used. A light diffusion function may be applied to the light guide structure between the light guide plates 210 .

[0182] When the longitudinal length L and the lateral length W of each surface-emitting light source 200 are, for example, approximately 24.3 mm and 21.5 mm, respectively, Fig. 9 The arrangement of the surface-emitting light source 200 shown is suitable for a 15.6-inch screen size with an aspect ratio of 16:9. Figure 7 The surface-emitting light source 300 shown can be well used for a backlight unit of a laptop computer having a screen size of 15.6 inches.

[0183] In this example, the upper surface 210a of the light guide plate 210, which is the upper surface of each surface light source 200, constitutes a light-emitting surface. Therefore, by changing the number of surface light sources 200 included in the surface light source 300 or changing the configuration of the surface light source 200, the surface light source 300 can be easily applied to a variety of liquid crystal panels with different screen sizes. That is, there is no need to re-perform optical calculations related to the light guide plate 210 in the surface light source 200, or to re-make the mold for forming the light guide plate 210, and it is possible to flexibly respond to changes in screen size. Therefore, changes in screen size will not increase manufacturing costs and preparation time.

[0184] Fig.10 Shows the Fig. 9The plurality of surface light sources 200 shown are further arranged in a structure of 2 rows and 2 columns. In this case, a total of 512 surface light sources 200 can be used to form a surface light source 400 suitable for a 31.2-inch screen size with an aspect ratio of 16:9. For example, Fig.10 The arrangement of the surface emitting light sources 200 shown can be used in a backlight unit of a liquid crystal television, etc. Thus, according to this embodiment, it is relatively easy to obtain a light emitting surface with a larger area.

[0185] According to the method of forming a light-emitting surface with a larger area by combining a plurality of surface-emitting light sources 200, it is not necessary to redesign the optical system or remake the mold for forming the light guide plate according to the screen size, and it is possible to flexibly respond to liquid crystal panels of various screen sizes. That is, a backlight unit suitable for the screen size can be provided at low cost and in a short time. In addition, it has the following advantages: even if there is a light-emitting element that will not light up due to a short circuit, etc., it is only necessary to replace the surface-emitting light source including the light-emitting element that has produced the malfunction. It should be noted that in Fig. 9 and Fig.10 In the illustrated two-dimensionally arranged surface light source including a plurality of surface light sources 200 , one or more diffusion sheets and / or one or more prism sheets may be arranged on the upper surfaces 210a of the plurality of light guide plates 210 to cover the upper surfaces 210a together.

[0186] Fig.11 FIG. 2 shows a light emitting module according to another embodiment of the present disclosure. Figure 2 Compared with the light emitting module 100A described above, Fig.11 The light emitting module 100B shown includes a light guide plate 110B instead of the light guide plate 110A.

[0187] exist Fig.11 In the illustrated structure, the upper surface 110a of the light guide plate 110B has a first hole portion 10B that is opposite to the second hole portion 20 on the lower surface 110b. The first hole portion 10B includes a first portion 11B having a first side surface 11c and a second portion 12A having a second side surface 12c. Fig.11 As shown, the first portion 11B further has a bottom surface 11b connected to the first side surface 11c. That is, in this example, the first portion 11B has an inverted truncated cone shape defined by the first side surface 11c and the bottom surface 11b. The diameter of the circular shape of the bottom surface 11b of the first portion 11B is, for example, about 0.3 mm.

[0188] Typically, the bottom surface 11b of the first portion 11B is a flat surface parallel to the upper surface 110a of the light guide plate 110B. By setting the shape of the first portion 11B of the first hole 10B to include the bottom surface 11b, the volume reduction of the reflective resin layer 130 can be suppressed, and the depth of the first hole 10B can be reduced. That is, the light emitting module 100B can be made thinner.

[0189] Fig.12 A light emitting module according to yet another embodiment of the present disclosure is shown. Fig.12 The light emitting module 100C shown in the figure has a light guide plate 110C. As shown in the figure, unlike the light guide plates 110A and 110B described above, the second hole portion 20 is not provided on the lower surface 110b side of the light guide plate 110C, and the light reflecting member 140 covers substantially the entire lower surface 110b of the light guide plate 110C. Fig.12 In, with Figure 2 Similarly, a cross section of the light emitting module 100C when cut perpendicularly to the upper surface 210a of the light guide plate 210 near the center of the light emitting module 100C and an exemplary appearance of the light emitting module 100C when observed perpendicularly to the upper surface 210a from the upper surface 210a side of the light guide plate 210 are schematically shown in one figure.

[0190] In the embodiment of the present disclosure, it is not necessary to form the second hole portion 20 in the light guide plate. Fig.12 As shown in the example, the light emitting body 100U may be bonded to the lower surface side of the light emitting module 100C, that is, the lower surface 110b of the light guide plate 110C in this case. The light emitting body 100U may be bonded to the lower surface 110b of the light guide plate 110C using the above-mentioned bonding member 190. It should be noted that, instead of the light emitting body 100U, the light emitting element 120 may be fixed to the lower surface 110b of the light guide plate 110C via the wavelength conversion member 150.

[0191] exist Fig.12 In the illustrated structure, a wavelength conversion member 150 is sandwiched between the light emitting element 120 and the light guide plate 110C. Here, the wavelength conversion member 150 has a rectangular shape in a plan view, such as Fig.12 As shown in the lower half of the figure, the wavelength conversion component 150 is located in a region further inside the opening 12a defining the outer shape of the first hole portion 10A in a plan view. In this example, one side of the rectangular shape of the wavelength conversion component 150 is parallel to one side of the rectangular shape of the light guide plate 110C, but the wavelength conversion component 150 may be arranged on the lower surface 110b side of the light guide plate 110C in a manner inclined relative to one side of the rectangular shape of the light guide plate 110C.

[0192] It should be noted that adjusting the thickness of the wavelength conversion member 150 so that the entire side surface is covered by the light reflecting member 140 can suppress light leakage from the lower surface 100b side of the light emitting module 100C, which is advantageous from the perspective of light output efficiency. Fig.11 The first hole portion 10B having the shape shown is substituted for the first hole portion 10A of the light guide plate 110C.

[0193] Fig.13 A cross section of a light emitting module according to yet another embodiment of the present disclosure is schematically shown. Fig.13 The light emitting module 100N shown in the figure has a light guide plate 110B and a light emitting body 100T including a light emitting element 120 and a wavelength conversion component 150A. Fig.13 As schematically shown, the light emitting body 100T is arranged at the bottom of the second hole portion 20A of the light guide plate 110B using a bonding member 190 .

[0194] In this example, the wavelength conversion member 150A covers not only the upper surface 120a of the light emitting element 120, but also the side surface of the element body 122. In this way, the shape of the wavelength conversion member is not limited to a plate shape, but may be a shape that covers the side surface of the light emitting element 120. In addition, in this example, the light reflecting member 140 also covers the wavelength conversion member 150A and the portion of the light emitting element 120 located on the side opposite to the upper surface 110a of the light guide plate 110B. However, the lower surface of the electrode 124 of the light emitting element 120 is exposed from the lower surface 140b of the light reflecting member 140 on the lower surface 100b side of the light emitting module 100N. According to such a structure, it is possible to suppress the light traveling from the light emitting element 120 toward the lower surface 100b side of the light emitting module 100N from leaking from the lower surface 140b.

[0195] Fig.14 A cross section of a light emitting module according to still another embodiment is schematically shown. Fig.11 The light emitting module 100P shown in the figure has a light guide plate 110B, a light emitting body 100R and a wavelength conversion sheet 350. Fig.14 In the illustrated structure, the wavelength conversion sheet 350 is located on the upper surface 100a of the light guide plate 110B. The wavelength conversion sheet 350 may be in contact with the upper surface 100a of the light guide plate 110B, or may be arranged above the light guide plate 110B at a distance from the upper surface 100a of the light guide plate 110B. In the case where an optical sheet such as a diffusion sheet and a prism sheet is further arranged above the light guide plate 110B, preferably, the diffusion sheet, the wavelength conversion sheet 350, and the prism sheet are sequentially arranged above the light guide plate 110B from the side close to the upper surface 100a. That is, preferably, the diffusion sheet is located between the upper surface 100a of the light guide plate 110B and the wavelength conversion sheet 350, and the wavelength conversion sheet 350 is located between the diffusion sheet and the prism sheet.

[0196] Typically, the wavelength conversion sheet 350 is a sheet of resin in which particles of a phosphor are dispersed. By using such a wavelength conversion sheet 350, the phosphor can be uniformly arranged above the light guide plate 110B. The same effect can be obtained when the light guide plate 110A is used instead of the light guide plate 110B. The phosphor can use a known material. Examples of the phosphor are fluoride-based phosphors such as KSF-based phosphors, nitride-based phosphors such as CASN, YAG-based phosphors, β-sialon phosphors, etc. The phosphor can also be a quantum dot phosphor.

[0197] Compared with the above-mentioned light emitting body 100U, the light emitting body 100R includes a plate-shaped light-transmitting member 320 instead of the wavelength conversion member 150. That is, the light emitting body 100R includes the light emitting element 120, the light-transmitting member 320, the bonding member 160, and the light reflecting member 170.

[0198] The light-transmitting component 320 is formed of a light-transmitting material. As the material of the light-transmitting component 320, silicone resin, modified silicone resin, epoxy resin, modified epoxy resin, urea resin, phenolic resin, acrylic resin, polyurethane resin or fluororesin, or a resin containing two or more of these resins can be used. By dispersing a material having a different refractive index from the base material in the material of the light-transmitting component 320, a light diffusion function can also be given to the light-transmitting component 320. For example, particles such as titanium dioxide and silicon oxide can be dispersed in the base material of the light-transmitting component 320.

[0199] Fig.15 A cross section of a light emitting module according to yet another embodiment of the present disclosure is schematically shown. Fig.15 The light emitting module 100D shown is also an example of the light emitting module 100 constituting the above-mentioned surface emitting light source 200, and as shown in the figure, it includes a light guide plate 110D having an upper surface 110a and a lower surface 110b and a light emitting element 120 arranged on the lower surface 110b side of the light guide plate 110D.

[0200] The upper surface 110a of the light guide plate 110D has a first region 111A formed with a plurality of convex portions or concave portions in at least a portion thereof. The first region 111A is located in a region of the upper surface 110a that does not overlap with the first hole portion 10C. Fig.15 In the illustrated example, a plurality of protrusions 110d are arranged in the first region 111A.

[0201] By providing, for example, a plurality of convex portions 110d in a region not overlapping with the first hole portion 10A on the surface on the upper surface 110a side of the light guide plate 110D, the light from the light emitting element 120 introduced into the light guide plate 110D from the lower surface 110b side of the light guide plate 110D can be effectively output from the first region 111A. That is, the brightness of the first region 111A when viewed from the normal direction of the upper surface 110a of the light guide plate 110D can be relatively improved.

[0202] Fig.16 The diagram schematically shows the light guide plate 110D viewed from the normal direction of the upper surface 110a. Fig.15 The exemplary appearance of the light emitting module 100D shown in FIG. In this example, the first region 111A occupies the entire region of the upper surface 110a that does not overlap with the first hole portion 10A, and a plurality of convex portions 110d are formed in the first region 111A in the form of a plurality of dots. It should be noted that Fig.15 and Fig.16 The diagram is merely a schematic diagram for explaining the structure of the upper surface 110a of the light guide plate 110D, and the number or shape of the plurality of protrusions 110d and the like may not be strictly consistent between the cross-sectional view and the plan view. This also applies to other drawings of the present disclosure.

[0203] like Fig.16 As shown schematically, the proportion of the convex portion 110d per unit area in the first region 111A increases in a concentric circle shape with the light emitting element 120 as the center. In this example, each of the plurality of convex portions 110d has a circular shape in a plan view, and the diameter of the circular shape of the convex portion 110d increases as it moves away from the center of the light guide plate 110D. More specifically, Fig.16 Compared with the convex portion 110d in the area sandwiched between the imaginary circle R1 and the opening 10a of the first hole portion 10A, which is drawn with a dotted line and centered on the position of the light emitting element 120, the convex portion 110d in the area sandwiched between the imaginary circle R1 and the imaginary circle R2 that is larger than the imaginary circle R1 has a larger diameter. Moreover, among the plurality of convex portions 110d, the diameter of the convex portion 110d in the area outside the imaginary circle R2 is larger than the diameter of the convex portion 110d in the area sandwiched between the imaginary circle R1 and the circle R2. Fig.16 It can be understood from the structure shown that the diameters of the plurality of protrusions 110 d do not need to increase uniformly as they move away from the light emitting element 120 .

[0204] like Fig.16As exemplified, by increasing the proportion of the plurality of protrusions 110d per unit area in the first region 111A in a concentric circle shape with the light emitting element 120 as the center, it is possible to relatively increase the light emitted from a position away from the light emitting element 120. For example, in this example, the plurality of protrusions 110d disposed near the four corners of the upper surface 110a of the light guide plate 110D have the largest diameter among the protrusions 110d disposed in the first region 111A. Therefore, the brightness near the four corners of the upper surface 110a of the light guide plate 110D can be relatively increased compared to other regions of the first region 111A. The result of increasing the brightness of the region that tends to become relatively dark is that it is possible to more effectively suppress uneven brightness while suppressing an increase in the thickness of the light guide plate 110D.

[0205] exist Fig.16 In the structure of the example, the plurality of protrusions 110d are points of a circular shape. The diameter of the circular shape is, for example, in the range of 1 μm to 500 μm. Of course, the shape of each protrusion 110d when viewed from above is not limited to a perfect circle. The shape of each of the plurality of protrusions 110d when viewed from above may also be an elliptical shape, a deformed circular shape, a polygonal shape, or an indefinite shape. It should be noted that in this specification, the shape of a protrusion or a recess when viewed from above refers to the shape of the outer edge when the protrusion or recess is projected onto a plane parallel to the upper surface of the light guide plate. In the case where the shape of the protrusion (or recess) when viewed from above is a shape other than a circular shape, the diameter of the imaginary circle that encompasses the outer edge of the protrusion (or the opening of the recess) is, for example, in the above range.

[0206] If the convex portion 110d has a shape protruding from the upper surface 110a of the light guide plate 110D, it can increase the light output from the upper surface 110a by suppressing total reflection inside the light guide plate 110D. Therefore, the convex portion 110d can have various shapes such as a hemispherical shape, a conical shape, a pyramid shape, and a truncated pyramid shape.

[0207] exist Fig.16 In the example shown, the plurality of convex portions 110d are two-dimensionally arranged in the first region 111A in such a manner that the centers are located at the grid points of the triangular grid. Of course, the arrangement of the plurality of convex portions 110d is not limited to this example, and a suitable arrangement can be adopted according to the desired optical characteristics. For example, the plurality of convex portions 110d can be two-dimensionally arranged in the first region 111A in such a manner that the centers are located at the grid points of the square grid.

[0208] Fig.17 Another example of a light guide plate having a plurality of convex portions on the upper surface is shown. Fig.17The light emitting module 100E shown has a light guide plate 110E on its upper surface 110a, and the light guide plate 110E includes a first area 111B and a second area 112B located inside the first area 111B. The second area 112B is an annular area surrounding the first hole 10C in the upper surface 110a of the light guide plate 110E, and the first area 111B is an area located outside the second area 112B and surrounds the second area 112B.

[0209] exist Fig.17 In the example shown, the first region 111B is a region on the upper surface 110a that is located outside the imaginary circle R1, and a plurality of convex portions 110d are provided on the surface. Fig.16 The example described is the same, the diameter of the circular shape of the convex portion 110d located outside the above-mentioned imaginary circle R2 in the first region 111B is larger than the diameter of the circular shape of the convex portion 110d located inside the imaginary circle R2. The area outside the imaginary circle R2 in the first region 111B can be called the "outer region", and the area near the light-emitting element 120 in the first region 111B that is closer to the outer region, in other words, the area sandwiched by the imaginary circle R1 and the imaginary circle R2 can be called the "inner region". Fig.17 In FIG. 1 , for easy understanding, the outer region 111Ba is indicated as a region with dense shading, and the inner region 111Bb is indicated as a region with sparse shading.

[0210] In addition, the second region 112B is a region of the upper surface 110a sandwiched between the imaginary circle R1 and the opening 10a of the first hole portion 10C, and no convex portion 110d is provided on its surface. Therefore, in this example, the surface of the second region 112B is a flat surface. Fig.17 As shown in the example, each convex portion 110d does not need to be formed in the entire first region 111B, and only needs to be provided in at least a portion of the first region 111B. By providing, for example, a plurality of convex portions 110d in a region relatively far from the light emitting element 120 in the light guide plate 110E, the light output from the region relatively far from the light emitting element 120, that is, the first region 111B, is increased compared to the second region 112B. As a result, the brightness of the first region 111B located further away from the light emitting element 120 is increased, and the occurrence of uneven brightness can be more effectively reduced.

[0211] In this way, Figure 15 to Figure 17In the example shown, on the upper surface 110a of the light guide plate, the proportion of the multiple protrusions 110d per unit area is increased in a concentric circle shape with the light emitting element 120 as the center. Here, the "concentric circle shape" in this specification refers to the same center, and it is not intended to limit multiple shapes with the same center to perfect circles. The above-mentioned imaginary circle R1 and / or imaginary circle R2 are not limited to perfect circles, and can be ellipses or the like. For example, in the case where the upper surface 110a of the light guide plate 110E is a rectangular shape, the imaginary circle R1 and the imaginary circle R2 can also be elliptical shapes. In this case, the center of these ellipses refers to the position where the major axis and the minor axis of the ellipse intersect.

[0212] As described above, the convex portion 110d can increase the light output from the upper surface 110a as long as it has a shape protruding from the upper surface 110a of the light guide plate. Therefore, a configuration can be adopted in which the ratio of the plurality of convex portions 110d per unit area is constant in the first region.

[0213] Fig.18 Still another example of a light guide plate having a plurality of convex portions on the upper surface is shown. Fig.18 The light emitting module 100K shown has a light guide plate 110K on its upper surface 110a, and the light guide plate 110K includes a first area 111F and a second area 112F located inside the first area 111F. In this example, a plurality of convex portions 110d are selectively provided in the first area 111F with a certain size and arrangement interval. It should be noted that as long as the proportion of the plurality of convex portions 110d per unit area is constant, one or both of the size and arrangement interval of the plurality of convex portions 110d may not be constant. Fig.18 The illustrated structure can relatively improve the brightness of the first region 111F provided with the plurality of protrusions 110d on the upper surface 110a of the light guide plate. The second region 112F may be omitted and the plurality of protrusions 110d may be provided on the entire upper surface 110a.

[0214] The shape of the convex portion provided in the first region is not limited to these examples. For example, the convex portion may also be formed in the form of a convex ring having a circular ring shape. In this case, by expanding the width of, for example, a plurality of convex rings as they are away from the light emitting element 120, the proportion of the plurality of convex portions per unit area in a top view can be expanded concentrically with the light emitting element 120 as the center. Therefore, similar to the case where a plurality of convex portions are arranged in the form of a plurality of points in the first region, the brightness of the position away from the light emitting element 120 in the first region can be increased, thereby obtaining an effect of suppressing uneven brightness.

[0215] The upper surface 110a may be provided with a mixture of a plurality of convex portions each having an annular shape and a plurality of convex portions each having a dot shape. By arranging the dot-shaped convex portions in addition to the annular convex portions, the generation of an annular light-dark pattern can be suppressed compared to the case where only the annular convex portions are arranged.

[0216] In addition, a plurality of recesses may be formed instead of a plurality of protrusions. In this case, the plurality of recesses have a shape in which, for example, the openings thereof become larger as they are away from the light emitting element 120.

[0217] The multiple recesses may be, for example, multiple points. Here, the "point" in this specification generally refers to a smooth structure represented by a circle or an ellipse when viewed from above, and the "point" in this specification should be interpreted as also including any of a shape protruding from the upper surface 110a of the light guide plate and a shape recessed relative to the upper surface 110a. In addition, the multiple recesses may be formed in the first area of ​​the upper surface 110a in the form of annular grooves. By expanding the width of the annular groove as it moves away from the light-emitting element 120, the proportion of the multiple recesses per unit area when viewed from above can be expanded concentrically with the light-emitting element 120 as the center. Alternatively, the intervals between the multiple recesses each having an annular shape may be reduced.

[0218] In addition, a plurality of convex portions and a plurality of concave portions may be mixedly arranged in the first area. The first area of ​​the upper surface 110a of the light guide plate may have any combination of two or more shapes selected from a plurality of convex portions each having a dot shape, a plurality of concave portions each having a dot shape, a plurality of convex portions each having a circular ring shape, and a plurality of concave portions each having a circular ring shape.

[0219] [Example]

[0220] Next, a plurality of samples with different structures of the first hole portion were prepared, and by investigating the distribution of brightness when the light-emitting element was turned on, the effect of suppressing brightness unevenness brought about by setting a two-stage inclination on the side of the first hole portion and selectively forming a reflective resin layer 130 inside the first portion of the first hole portion close to the lower surface of the light guide plate was verified.

[0221] <Example>

[0222] As samples of the examples, Fig.11 The light emitting module 100B shown has a surface emitting light source in which a plurality of light emitting modules having the same structure are arranged in four rows and four columns. Here, the entire first portion 11B of the first hole 10B is filled with a silicone resin containing titanium oxide particles.

[0223] <Comparative Example>

[0224] As a sample of a comparative example, a surface emitting light source was prepared in which the first hole of each light emitting module had a conical shape with a single inclined side surface and the entire first hole was filled with a silicone resin containing titanium oxide particles.

[0225] Fig.19 FIG. 2 shows the appearance of the sample of the embodiment observed from the upper surface side of the light guide plate. Fig.19 , the appearance of the light emitting element when the light emitting element is turned on in a state where a diffusion sheet, a first prism sheet, and a second prism sheet are placed on the upper surface side of the light guide plate. Fig.19 same, Fig. 20 The appearance of the sample of the comparative example observed from the upper surface side of the light guide plate is shown, and the appearance when the light-emitting element is lit in a state where a diffusion sheet and a first prism sheet and a second prism sheet are placed on the upper surface side of the light guide plate is shown. Here, the prism sheets are arranged on the upper surface side of the light guide plate between the first prism sheet and the second prism sheet in such a manner that the ridge lines of the prisms are orthogonal to each other.

[0226] from Fig.19 and Fig. 20 From the comparison, it can be seen that in the sample of the embodiment, the uneven brightness when observed from the upper surface side of the light guide plate is further suppressed. Here, the uniformity of brightness is evaluated by the following method. First, the part of the central 2 rows and 2 columns of the 16 light-emitting modules arranged in 4 rows and 4 columns is taken out, and the taken out part is divided into multiple areas with a grid of any size. Next, the brightness of each divided area is measured. The maximum and minimum values ​​are extracted from the multiple brightness values ​​obtained by measuring the different areas, and the values ​​calculated using the calculation formula of ((minimum brightness value) / (maximum brightness value))*100 ("*" indicates multiplication) are compared as the "brightness uniformity (%)" of the sample.

[0227] The brightness uniformity of the sample of the comparative example is 78%. In contrast, the brightness uniformity of the sample of the embodiment is 92%. That is, in the sample of the embodiment, the difference between the maximum and minimum brightness in the portion of 2 rows and 2 columns located in the center is reduced. It can be seen that by making the inclination of the side surface of the first hole portion two-stage and selectively forming the light reflective resin layer in the first portion, the brightness unevenness on the upper surface of the light guide plate can be more effectively suppressed compared to the case where the light reflective resin layer is formed in the entire conical first hole portion.

[0228] Industrial Applicability

[0229] The embodiments of the present disclosure are useful for various lighting light sources, vehicle-mounted light sources, display light sources, etc. In particular, they can be effectively applied to backlight units for liquid crystal display devices. The light-emitting modules or surface-emitting light sources of the embodiments of the present disclosure can be well used for display device backlights of mobile devices that require strict thickness reduction, surface-emitting devices that can perform local dimming control, etc.

Claims

1. A light emitting module, characterized in that: have: A light guide plate having an upper surface provided with a first hole portion and a lower surface on a side opposite to the upper surface; a light emitting element disposed on a lower surface side of the light guide plate so as to face the first hole; and A reflective resin layer; The first hole portion includes a first portion and a second portion, The first portion has a first side surface inclined relative to the upper surface, The second portion has a second side surface inclined relative to the upper surface, and the second side surface is located between the opening of the upper surface and the first side surface of the first portion. The reflective resin layer is located in the first portion of the first hole. The first side surface is inclined more gently with respect to the upper surface than the second side surface is inclined with respect to the upper surface. The second side surface has a curved shape in a cross section perpendicular to the upper surface.

2. The light emitting module according to claim 1, characterized in that: The refractive index of the interior of the second portion of the first hole is lower than the refractive index of the reflective resin layer.

3. The light emitting module according to claim 1 or 2, characterized in that: The first portion of the first hole further has a bottom surface connected to the first side surface.

4. The light emitting module according to claim 1 or 2, characterized in that: The lower surface of the light guide plate has a second hole portion at a position opposite to the first hole portion. The light emitting element is located inside the second hole in a plan view.

5. The light emitting module according to claim 4, characterized in that: The light emitting module further includes a wavelength conversion member located inside the second hole and between the light emitting element and the light guide plate.

6. The light emitting module according to claim 1 or 2, characterized in that: The light emitting element is located inside the first hole in a plan view. The light emitting module further includes a wavelength conversion member located between the light emitting element and the light guide plate.

7. The light emitting module according to claim 1 or 2, characterized in that: The light emitting module further includes a wavelength conversion sheet located on or above the upper surface of the light guide plate.

8. The light emitting module according to claim 1 or 2, characterized in that: The light emitting element has an electrode on a side opposite to the light guide plate. The light emitting module further includes a light reflecting member covering at least a portion of the lower surface of the light guide plate.

9. The light emitting module according to claim 8, characterized in that: The light emitting module further includes a wiring layer located on the lower surface side of the light reflecting member and electrically connected to the electrode.

10. The light emitting module according to claim 8, characterized in that: The light reflecting member includes a wall portion protruding from the lower surface side toward the upper surface side, and the wall portion includes an inclined surface surrounding the light emitting element.

11. A surface emitting light source, characterized in that: A plurality of light-emitting modules are provided, wherein the light-emitting modules are the light-emitting modules according to any one of claims 1 to 10, The plurality of light emitting modules are arranged two-dimensionally.

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