Light Emitting Module

Abstract

To provide a light emitting module in which unevenness is reduced.SOLUTION: A light emitting module includes: a light guide member including an upper surface, a lower surface and a hole part opening on the lower surface side; a light source arranged in the hole part; and a first light reflective member. The lower surface includes an inclined surface which surrounds the hole part in an upper surface view, and which is positioned further on an outside than the first light reflective member. The inclined surface includes: a first region arranged between a first upper end positioned further on a lower side than an upper surface of the light source, and a first lower end positioned further on a lower side than the first upper end; and a second region arranged between a second upper end and a second lower end positioned further on a lower side than the second upper end, and which is positioned further on an outside than the first region in an upper surface view. A cross-sectional-view shape of the first and second regions is a shape which includes a curve line and / or a straight line arranged further on an upper side than first and second virtual lines connecting the first and second upper ends and the first and second lower ends with the shortest distance respectively.SELECTED DRAWING: Figure 1A

Description

[Technical field]

[0001] The present disclosure relates to a light emitting module. [Background technology]

[0002] Light-emitting modules using light-emitting elements such as light-emitting diodes have been proposed (Patent Documents 1 and 2, etc.). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2011-203720 A [Patent Document 2] JP 2013-26240 A Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present disclosure is to provide a light-emitting module with less uneven light emission. [Means for solving the problem]

[0005] The present disclosure includes the following configurations. (1) A light-guiding member including an upper surface serving as a light-emitting surface, a lower surface opposite to the upper surface, and a hole opening to the lower surface side; A light source disposed in the hole; a first light reflective member disposed above the light source; Equipped with the lower surface of the light guide member has an inclined surface surrounding the hole and positioned outside the first light reflective member in a top view, The inclined surface is a first region disposed between a first upper end located below the upper surface of the light source and a first lower end located below the first upper end on a side closer to the hole than the first upper end; a second region that is disposed between a second upper end that is located above the first upper end and a second lower end that is located below the second upper end and closer to the hole than the second upper end, and that is located outside the first region in a top view; a cross-sectional shape of the first region includes a curve and / or a straight line that is located above a first virtual line that connects the first upper end and the first lower end at the shortest distance, A light-emitting module, wherein the cross-sectional shape of the second region includes curves and / or straight lines that are located above a second virtual line that connects the second upper end and the second lower end at the shortest distance. (2) The light-emitting module of (1), wherein the hole is a bottomed hole having an opening on the lower surface side of the light-guiding member, and the first light-reflective member is disposed on the upper surface of the light-guiding member. (3) The light-emitting module according to (2), wherein the bottomed hole portion has a side surface and a bottom, and the first upper end is located below the bottom. (4) The light-emitting module of (3), wherein the height from a lower end of the bottomed hole to the first upper end of the first region is 12.5% ​​or more and 40% or less of the depth of the bottomed hole. (5) Any of the light-emitting modules (1) to (4) above, wherein the hole is a through-hole having openings on the upper and lower surfaces of the light-guiding member, and the first light-reflective member is disposed above the light source within the through-hole. (6) The light-emitting module according to any one of (1) to (5), wherein the first region and the second region are adjacent to each other. (7) The light emitting module according to any one of (1) to (6), wherein the light guiding member is quadrangular in top view, and the first region is widest between a center of the light guiding member and a corner of the light guiding member. Effect of the Invention

[0006] According to the present disclosure, it is possible to provide a light-emitting module with little unevenness in light emission. [Brief description of the drawings]

[0007] [Figure 1A]1 is a schematic top view showing a light-emitting module according to an embodiment; [Figure 1B] FIG. 1B is a schematic plan cross-sectional view taken along line IB-IB in FIG. 1A. [Figure 1C] FIG. 1B is a schematic cross-sectional plan view showing a modification of FIG. 1A. [Figure 2A] 1B is a top view of the light-guiding member in FIG. 1A. [Figure 2B] 1B is a bottom view of the light-guiding member in FIG. 1A. [Figure 2C] 2C is a schematic end view showing the IIC-IIC′ cross section of the light-guiding member of FIG. 2B. [Figure 2D] 2D is a schematic bottom view for explaining the size and the like of the light guide member in FIG. 2C. FIG. [Diagram 3] FIG. 1B is a schematic cross-sectional view showing the light source in FIG. 1A. [Figure 4A] 4B is a schematic cross-sectional view (cross-section along line IVC-IVC in FIG. 4B) showing a light-emitting module according to another embodiment, and FIG. [Figure 4B] 4B is a bottom view of the light-guiding member in FIG. 4A. FIG. [Figure 4C] 4C is a schematic cross-sectional view showing the IVC-IVC′ cross section of the light-guiding member of FIG. 4B. [Figure 4D] 4D is a schematic bottom view for explaining the size and the like of the light guide member in FIG. 4C. FIG. [Diagram 5] FIG. 11 is a schematic cross-sectional view showing a light-emitting module according to yet another embodiment. [Figure 6A] FIG. 4 is a top view showing a plurality of units of light guide members. [Figure 6B] FIG. 6B is a perspective view of the light-guiding member of FIG. 6A. [Figure 7] 1 is a schematic diagram showing a liquid crystal display device to which a light-emitting module of the present invention is applied; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] The present invention will be described in detail below with reference to the drawings. In the following description, terms indicating specific directions and positions (for example, "upper", "lower" and other terms including these terms) are used as necessary, but the use of these terms is an expression for facilitating understanding of the invention with reference to the drawings, and the meaning of these terms does not limit the technical scope of the present invention. In the following description, an XYZ Cartesian coordinate system is adopted. The optical axis of the light-emitting module is parallel to the Z axis. The Z direction is also referred to as the up-down direction or thickness direction. Furthermore, a top view does not necessarily refer only to a state viewed from the top, but may also refer to a state viewed from the bottom. Parts with the same reference numerals appearing in multiple drawings indicate the same or equivalent parts or members. Furthermore, the embodiments shown below are examples for embodying the technical ideas of the present invention, and do not limit the present invention to the following. The dimensions, materials, shapes, relative positions, etc. of the components described below are intended to be illustrative, and are not intended to limit the scope of the present invention, unless otherwise specified. The sizes and positional relationships of the members shown in the drawings may be exaggerated to clarify the explanation. In addition, end views showing only the cut surfaces may be used as cross-sectional views.

[0009] Embodiment 1 [Light Emitting Module] The light emitting module 20 according to the first embodiment includes a light guide member 10, a light source 1, and a first light reflective member 8, as shown in FIG. 1A. The light emitting module 20 may further include a light-transmitting member 6, sealing members 7 and 9, and the like.

[0010] One light emitting module may include one light source 1 as shown in FIG. 1A. Alternatively, one light emitting module may include multiple light sources 1 as in the arrangements shown in FIG. 6A and FIG. 6B. When one light emitting module includes multiple light sources 1, the multiple light sources 1 are connected so that each is driven independently, or the multiple light sources 1 are connected as one group so that each group is driven independently. This allows a light emitting module capable of local dimming.

[0011] As shown in FIGS. 2A to 2D, the light guide member 10 has an upper surface 101 and a lower surface 102 opposite to the upper surface 101. The light guide member 10 further has a hole 12 that opens to the lower surface 102. In the first embodiment, the hole 12 is a bottomed hole (recess) that opens only to the lower surface. The light source 1 is disposed in the hole 12. In the present embodiment, the bottomed hole 12 in which the light source 1 is disposed may be referred to as a recess (second recess). A first light reflective member 8 is disposed above the light source 1. In the present embodiment, the first light reflective member 8 is disposed on the upper surface 101 of the light guide member 10 located above the light source 1. When the upper surface 101 of the light guide member 10 located above the light source 1 has a recessed portion (may be referred to as a first recess 11), the first light reflective member 8 is disposed in the first recess 11.

[0012] (Light guiding components) The light guide member 10 is a light-transmitting plate-like member that receives light from a light source and outputs it as planar light. The upper surface 101 of the light guide member 10 is the emission surface of the light-emitting module and is an upper surface that extends in the XY plane direction perpendicular to the optical axis Z.

[0013] (Hole, bottomed hole (second recess)) The hole (second recess) 12 is a portion where the light source 1 is disposed. As shown in FIG. 2C, the second recess 12 is a recessed portion defined by a bottom (second bottom) 12a and a side (second side) 12b. The depth (H2 in FIG. 2C) of the second recess 12 can be, for example, 15% to 50% of the thickness of the light guide member, and preferably 10% to 40%. The depth of the second recess 12 can be 50% to 100% of the thickness of the light source 1.

[0014] The second recess 12 is surrounded by the inclined surface 13 in the top view. The second recess 12 and the first light reflective member 8 at least partially overlap in the top view. When the light guiding member 10 includes the first recess 11, it is preferable that the second recess 12 and the first recess 11 at least partially overlap. It is preferable that the center of the first light reflective member 8 and the center of the second recess 12 approximately coincide in the top view. When the light guiding member 10 includes the first recess 11, it is preferable that the center of the first recess 11 and the center of the second recess 12 approximately coincide in the top view.

[0015] The second recess 12 is a cylindrical or truncated pyramidal recess. For example, the second recess 12 may be a cylindrical recess, a prismatic recess, a truncated cone recess, a truncated pyramid recess, or a recess having a shape obtained by partially modifying these shapes. The shape of the opening of the second recess 12 in a plan view may be, for example, a polygonal shape such as a square, a pentagon, or a hexagon, a circle, or an ellipse.

[0016] As shown in FIG. 2C, the second recess 12 is defined by a bottom (second bottom 12a) including the deepest part of the second recess 12, and a side surface (second side surface 12b) surrounding the second bottom 12a in a top view. In a top view, the center of the opening of the second recess 12 and the center of the second bottom 12a preferably coincide with each other. The second bottom 12a is preferably a surface that is substantially perpendicular to the optical axis of the light-emitting module. In a cross section passing through the center of the second recess 12, the second side surface 12b of the second recess 12 can be a straight line, a curve that is convex or concave toward the center of the second recess 12, or a combination of these. The depth of the second recess 12 (H2 in FIG. 2C) can be, for example, 15% to 50% of the thickness of the light-guiding member (T in FIG. 2C), and is preferably 10% to 40%.

[0017] (slanted surface) As shown in Fig. 2C, the lower surface 102 of the light guide member 10 has an inclined surface 13 surrounding the second recess 12 in a top view. The inclined surface 13 has a lower end (for example, a first lower end of the first region) 130U on the side closer to the second recess 12, and is inclined to have a second upper end 132U outside the lower end 130U. The inclined surface 13 is disposed at a position not overlapping with the first light reflective member 8 in a top view. In other words, the innermost edge U2 of the inclined surface 13, i.e., the lower end 130U of the inclined surface 13, is disposed outside the outer edge U1 of the first light reflective member 8 in a top view.

[0018] On the lower surface 102, the lower end 12U of the second side surface 12b of the second recess 12 and the inclined surface 13 may be continuous or separated. In the example shown in FIG. 2C, the lower end 12U of the second side surface 12b and the inclined surface 13 are separated. That is, on the lower surface 102 side, a second portion 133, which is a surface approximately perpendicular to the optical axis, is disposed between the second recess 12 and the inclined surface 13. The distance (D9 in FIG. 2D) of such a second portion 133 is, for example, 5% to 15% of the length of one side of the light-guiding member 10. Note that such a second portion 133 is preferably a smooth surface.

[0019] The inclined surface 13 has a first region 131 and a second region 132. In a top view, the first region 131 is located outside the light source 1, and the second region 132 is located outside the first region 131. The first region 131 is a region disposed between a first upper end and a first lower end. The first upper end is located lower than the upper surface of the light source in the vertical direction of the light guide member. The first lower end is located lower than the first upper end. The second region 132 is a region disposed between a second upper end and a second lower end. The second upper end is located higher than the first upper end in the vertical direction of the light guide member. The second lower end is located lower than the second upper end.

[0020] The cross-sectional shape of the first region includes a curve and / or a straight line located above a first virtual line connecting the first upper end and the first lower end at the shortest distance. The cross-sectional shape of the two regions includes a curve and / or a straight line located above a second virtual line connecting the second upper end and the second lower end at the shortest distance. In other words, the first region 131 is configured with a concave curve that is concave toward the upper surface 101 side in the cross-sectional view, and the second region 132 is configured with a convex curve or a straight line that is convex toward the lower surface 102 side in the cross-sectional view.

[0021] The first region 131 and the second region 132 can be adjacent to each other as shown in Fig. 2C. In other words, the upper end (first upper end) of the first region 131 and the lower end (second lower end) of the second region can be aligned (131U in Fig. 2C).

[0022] The first region 131 and the second region 132 are preferably smooth surfaces. Alternatively, the first region 131 and the second region 132 may be rough surfaces. In this case, the surface roughness of the first region 131 and the surface roughness of the second region 132 may be approximately the same. Alternatively, the surface roughness of the first region 131 may be greater or smaller than the surface roughness of the second region 132.

[0023] The first region 131 has a first upper end 131U below the upper surface 1a of the light source 1 in the vertical direction. As shown in FIG. 1A, when the upper surface 1a of the light source 1 is in direct contact with the second bottom 12a of the second recess 12, the first upper end 131U of the first region 131 is located between the lower end 12U of the second side surface 12b of the second recess 12 and the upper surface 1a of the light source 1 in the vertical direction. When the upper surface 1a of the light source 1 and the second bottom 12a of the second recess 12 are joined via the translucent member 6, the upper end (first upper end 131U) of the first region 131 may be located below the bottom 12a of the hole 12 (the second bottom 12a of the second recess 12) in the vertical direction. In other words, it is preferable that the upper end of the first region 131 is located between the lower end and the upper end of the translucent resin member 3 of the light source 1. In this way, by adjusting the ratio of the first region 131 to the side surface of the light source 1, the light can be distributed and uneven light emission can be suppressed.

[0024] First upper end 131U is disposed at the uppermost side in first region 131. First upper end 131U is positioned at the outermost side in first region 131. With this arrangement, light emitted from the light emitting device can be efficiently guided to the upper surface, which is the light emitting surface.

[0025] The height of the first upper end 131U of the first region 131 can be adjusted depending on the thickness of the light-transmitting resin member 3. For example, the height (height T1 in FIG. 2C) of the first region 131 from the lower end (corresponding to 130U in FIG. 2C) of the second recess 12 in the vertical direction to the first upper end 131U is preferably smaller than the depth H2 of the second recess 12. Alternatively, when the thickness of the light-transmitting resin member 3 disposed in the second recess 12 is different from the depth H2 of the second recess 12, it is preferable to set the height T1 smaller than the thickness of the light-transmitting resin member 3. For example, the height T1 may be 12.5% ​​or more and 40% or less of the thickness of the light-transmitting resin member 3, and preferably 25% or more and 70% or less.

[0026] The first region 131 may have a rise angle (α1 in FIG. 2C) of 90 degrees or more and 160 degrees or less at the edge closest to the second recess 12. By setting the rise angle on the second recess side in this manner, the light emitted from the light source can be dispersed at the corners in the light-guiding member 10. Here, the rise angle refers to the angle between the tangent to the lower end of the inclined surface (the first lower end of the first region) and a plane perpendicular to the optical axis. On the side of the first region 131 farther from the second recess 12, the rise angle may be, for example, 1 degree or more and 20 degrees or less from the plane perpendicular to the optical axis, and preferably 1 degree or more and 8 degrees or less.

[0027] 2B, the first region 131 has a different width from the center of the second recess 12 to the upper end of the first region 131 (the width of the first region 131) in a top view. For example, when the shape of the light-guiding member 10 in a top view is a rectangle, it is preferable that the first region 131 has the widest width between the center of the light-guiding member 10 and a corner of the light-guiding member 10 and the narrowest width between the center of the light-guiding member 10 and the center of a side of the light-guiding member 10 in a top view. This can increase the proportion of light guided in the corner direction of the light-guiding member 10.

[0028] 2D, in a top view, a distance D1 between the first upper end 131U and the second upper end 132U located on a straight line L1 passing through the center of the light guiding member 10 and the center of a side of the light guiding member 10 can be 10% to 30% of the length H0 of one side of the light guiding member 10. A distance D2 from the first upper end 131U closest to a corner of the light guiding member 10 to the closest side of the light guiding member 10 can be 5% to 15% of the length H0 of one side of the light guiding member 10. In addition, a distance D3 between the first upper end 131U and the second upper end 132U located on a straight line L2 passing through the center of the light guiding member 10 and the corner of the light guiding member 10 can be 7% to 17% of the length H0 of one side of the light guiding member 10. A distance D4 between the first upper end 131U located on the straight line L1 and the lower end 130U (first lower end of the first region) of the inclined surface 13 can be 5% to 18% of the length H0 of one side of the light guide member 10. A distance D5 between the first upper end 131U located on the straight line L2 and the lower end 130U (first lower end of the first region) of the inclined surface 13 can be 25% to 45% of the length H0 of one side of the light guide member 10. As shown in FIG. 1B, the first upper end 131U of the first region 131 may change in a curved manner in top view, or the light guide member 10A may change linearly as shown in FIG. 1C. With such a shape, the light emitted from the light source can be efficiently guided to the upper surface, which is the light emitting surface.

[0029] The second region 132 has a second upper end 132U above the first upper end 131U in the vertical direction. The second region 132 has a second upper end 132U above the upper surface 1a of the light source 1 in the vertical direction. The second upper end 132U is disposed at the uppermost position in the second region 132 in the vertical direction. The second upper end 132U is disposed at the outermost position in the second region 132 in the top view. It is preferable that the entire second region 132 is disposed above the first region 131. In other words, it is preferable that the lower end (second lower end) of the second region 132 is disposed at the lowermost position in the second region 132 in the vertical direction. In this way, by making the second region 132 a surface that is concave with respect to the upper surface, the light emitted from the light emitting device can be efficiently guided to the upper surface, which is the light emitting surface, while being condensed.

[0030] In the second region 132, it is preferable that the height from the second portion 133 to the second upper end 132U (height T2 in FIG. 2C) is greater than the depth H2 of the second recess 12. For example, this height T2 can be 112.5% ​​or more and 140% or less of the depth H2 of the second recess.

[0031] The rising angle (α2 in FIG. 2C ) of the inclination at the edge of the second region 132 closest to the second recess 12 can be 130 degrees or more and 170 degrees or less, and preferably 135 degrees or more and 165 degrees or less. By setting the rising angle on the second recess side in this manner, the light emitted from the light source can be efficiently dispersed within the light guide member 10. The rising angle α1 of the first region 131 and the rising angle α2 of the second region 132 may be approximately the same, or α1<α2.

[0032] (First recess) 1A, 2A, and 2C, the upper surface 101 of the light-guiding member 10 may include a first recess 11. The first recess 11 has a function of, for example, spreading light within the plane of the light-guiding member 10. Note that the first recess 11 is not essential, and the upper surface 101 of the light-guiding member 10 may be a flat surface.

[0033] The first recess 11 is a depression having a substantially pyramidal or truncated pyramidal shape. For example, the first recess 11 may be a cone, a pyramidal, a truncated cone, a truncated pyramidal, or a shape obtained by partially modifying these. The shape of the opening of the first recess 11 as viewed from above may be, for example, a polygon such as a rectangle, a pentagon, or a hexagon, or may be a circle or an ellipse as shown in FIG. 2A. The size of the opening of the first recess 11 is preferably at least larger than the size of the light source 1 as viewed from above.

[0034] The first recess 11 is located at the center of the first recess 11 in top view. As shown in FIG. 2C, the first recess 11 is defined by a bottom (first bottom) 11a including the deepest part of the first recess 11 and a side (first side) 11b surrounding the first bottom 11a in top view. The first bottom 11a of the first recess 11 is preferably a surface substantially perpendicular to the optical axis of the light source. The side 11b defining the first recess 11 can be a straight line, a curved line that is convex or concave toward the center of the first recess 11, or a combination of these in a cross section passing through the center of the first recess 11. The depth of the first recess 11 (H1 in FIG. 2C) can be, for example, 10% to 45% of the thickness (T in FIG. 2C) of the light guide member 10, and preferably 10% to 38%.

[0035] The upper surface 101 may have a first portion 14 including a surface perpendicular to the optical axis around the first recess 11. The first portion 14 may be a flat surface or a surface having minute recesses or protrusions. The first portion 14 is located at a position furthest from the lower surface in the optical axis direction. The first portion 14 may be omitted. In other words, the entire upper surface 101 may be the first recess 11.

[0036] Examples of the material of the light guide member 10 include resin materials such as thermoplastic resins such as acrylic, polycarbonate, cyclic polyolefin, polyethylene terephthalate, and polyester, thermosetting resins such as epoxy and silicone, and glass. The thickness (T in FIG. 2C) of the light guide member 10 can be, for example, 0.1 mm or more and 5 mm or less, and preferably 0.5 mm or more and 3 mm or less. The size of the light guide member 10 can be, for example, 1 cm or more and 200 cm or less on one side of the upper surface 101 or the lower surface 102, and preferably 3 cm or more and 30 cm or less. The shape of the light guide member 10 in a plan view can be, for example, a rectangle, a circle, or the like, and preferably a rectangle.

[0037] The light guide member 10 is preferably a single layer. Alternatively, it may have a laminated structure in which a plurality of light-transmitting layers are laminated. In the case of a laminated structure, it may have a structure in which layers of the same material or layers of different materials are bonded with an adhesive sheet or the like. Also, a layer with a different refractive index, for example, an air layer, may be provided between any layers. This makes it easier to diffuse light, and a light-emitting module with reduced unevenness in brightness can be obtained.

[0038] The light guide member 10 can be prepared by molding, for example, injection molding, transfer molding, compression molding, thermal transfer, etc. The light guide member 10 can also be prepared by purchasing it.

[0039] (First light reflective member 8) The first light reflective member 8 is disposed above the light source 1. In this embodiment, the first light reflective member 8 is disposed, for example, inside the first recess 11. The first light reflective member 8 is preferably disposed in a region of the first recess 11 that overlaps with at least the light source 1 in a top view. This makes it possible to reflect in the lateral direction, particularly the light emitted directly upward from the light source, and to prevent the area directly above the light source from becoming too bright compared to other areas.

[0040] When the light guide member has a first recess 11, the first light reflective member 8 is preferably disposed in the first recess 11 at a position spaced apart from the upper end of the first side surface that defines the first recess 11. In other words, a part of the first side surface 11b of the first recess 11 is preferably exposed from the first light reflective member 8. When viewed from above, the first light reflective member 8 is disposed outside an inclined surface 13 of the lower surface 102, which will be described later.

[0041] Moreover, in top view, the size of first light reflective member 8 is preferably larger than that of second recess 12. In other words, in top view, the outer edge of first light reflective member 8 is preferably disposed outside the outer edge of second recess 12.

[0042] When the light guide member includes the second portion 133 around the second recess 12, it is preferable that the second portion 133 and the first light reflective member 8 overlap in a top view.

[0043] Examples of the first light reflective member 8 include light reflective materials such as light reflective metals, resin materials containing light diffusing agents, and resin materials containing air bubbles. A white resin member containing a light diffusing agent can be used as a light-transmitting resin material. Examples of light diffusing agents include TiO2, SiO2, Al2O3, ZrO2, and ZnO. Examples of the resin material contained in the sealing member 7 include thermoplastic resins such as acrylic, polycarbonate, cyclic polyolefin, polyethylene terephthalate, and polyester, or thermosetting resins such as epoxy and silicone. In particular, the first light reflective member 8 is preferably a silicone resin containing TiO2 or polyethylene terephthalate containing air bubbles.

[0044] (light source) The light source 1 includes a light emitting element 2. The light source 1 may be only the light emitting element 2, or may be a light emitting device including the light emitting element 2 and a resin material or the like as shown in FIGS.

[0045] The light-emitting element 2 can be, for example, a semiconductor light-emitting element having a light-transmitting substrate such as sapphire and a semiconductor structure laminated on the light-transmitting substrate. The semiconductor structure includes an n-side semiconductor layer, a p-side semiconductor layer, and an active layer sandwiched between the n-side semiconductor layer and the p-side semiconductor layer. The active layer may have a single quantum well (SQW) structure or a multiple quantum well (MQW) structure including multiple well layers. The semiconductor structure includes multiple semiconductor layers made of nitride semiconductors. The nitride semiconductors are In x Al y Ga 1-x-y The term includes semiconductors of all compositions in which the composition ratios x and y in the chemical formula N (0≦x, 0≦y, x+y≦1) are changed within the respective ranges. The emission peak wavelength of the active layer can be appropriately selected depending on the purpose. The active layer is configured to be capable of emitting, for example, visible light or ultraviolet light.

[0046] The semiconductor structure may include a plurality of light emitting sections including an n-side semiconductor layer, an active layer, and a p-side semiconductor layer. When the semiconductor structure includes a plurality of light emitting sections, each light emitting section may include well layers having different emission peak wavelengths, or may include well layers having the same emission peak wavelength. The same emission peak wavelength includes a case where the emission peak wavelengths vary by about several nm. The combination of emission peak wavelengths of the plurality of light emitting sections may be appropriately selected. For example, when the semiconductor structure includes two light emitting sections, the combination of light emitted by each light emitting section may be blue light and blue light, green light and green light, red light and red light, ultraviolet light and ultraviolet light, blue light and green light, blue light and red light, or green light and red light. For example, when the semiconductor structure includes three light emitting sections, the combination of light emitted by each light emitting section may be blue light, green light, and red light. Each light emitting section may include one or more well layers having emission peak wavelengths different from other well layers.

[0047] The light-emitting element is preferably a rectangular element with vertical and horizontal dimensions of 1 mm or less when viewed from above, and preferably an element with a size of 500 μm or less, and more preferably an element with a size of 200 μm or less. This makes it possible to realize high-definition images, for example, when performing local dimming on a liquid crystal display device.

[0048] As the light source 1, a light emitting device including a light-transmitting resin member 3 that covers the light emitting surface of the light emitting element 2 can be used as shown in Fig. 3. The light-transmitting resin member 3 may cover the light emitting surface and side surfaces of the light emitting element 2. As the light-transmitting resin member 3, a light-transmitting material such as an epoxy resin, a silicone resin, or a mixture of these resins can be used. As the base material of the light-transmitting resin member 3, a material having a higher refractive index than the material of the light guide member 10 is preferable.

[0049] The light-transmitting resin member 3 may contain, in addition to the above-mentioned light-transmitting material, a phosphor that converts the wavelength of the light from the light-emitting element 2. The phosphor may be an yttrium-aluminum-garnet phosphor (e.g., Y3(Al,Ga)5O 12 :Ce), lutetium aluminum garnet phosphors (e.g., Lu3(Al,Ga)5O 12 :Ce), terbium aluminum garnet phosphors (e.g., Tb3(Al,Ga)5O 12 :Ce), β-sialon phosphors (e.g., (Si,Al)3(O,N)4:Eu), α-sialon phosphors (e.g., Ca(Si,Al) 12 (O,N) 16 :Eu), nitride-based phosphors such as CASN-based phosphors (e.g., CaAlSiN3:Eu) or SCASN-based phosphors (e.g., (Sr,Ca)AlSiN3:Eu), fluoride-based phosphors such as KSF-based phosphors (e.g., K2SiF6:Mn), KSAF-based phosphors (e.g., K2(Si,Al)F6:Mn) or MGF-based phosphors (e.g., 3.5MgO·0.5MgF2·GeO2:Mn), phosphors having a perovskite structure (e.g., CsPb(F,Cl,Br,I)3), or quantum dot phosphors (e.g., CdSe, InP, AgInS2, or AgInSe2), etc. can be used.

[0050] The light-transmitting resin member 3 may be a single layer or a laminated structure in which multiple layers are laminated. The light-transmitting resin member 3 may also contain a light diffusing material. Examples of light diffusing materials include TiO2, SiO2, Al2O3, ZrO2, and ZnO.

[0051] The light-transmitting resin member 3 preferably has an area larger than the light-emitting surface (upper surface) of the light-emitting element 2. In other words, the outer edge of the light-transmitting resin member 3 is preferably sized to be disposed outside the outer edge of the light-emitting surface of the light-emitting element 2. The light-transmitting resin member 3 may be joined to the light-emitting surface of the light-emitting element 2 by a light-transmitting joining member 4. The light-transmitting joining member 4 is preferably made of a material that transmits 60% or more of the light emitted from the light-emitting element 2, and preferably transmits 90% or more of the light. Examples of materials for the light-transmitting joining member 4 include light-transmitting thermosetting resin materials such as epoxy resin and silicone resin.

[0052] As the light source 1, for example, as shown in Fig. 3, a light emitting device having a structure including a light reflective covering member 5 covering the side surface and electrode surface of the light emitting element 2 can be used. Examples of the covering member 5 include resin materials including TiO2, SiO2, Al2O3, ZrO2, ZnO, etc. When the light transmissive resin member covers the side surface of the light emitting element, the covering member 5 can cover the lower surface of the light transmissive resin member and the lower surface of the light emitting element (surface other than the electrode).

[0053] The second recess 12 of the light guiding member 10 includes a light-transmissive member 6 that bonds the light guiding member 10 and the light source 1. In this case, the light-transmissive member 6 may be disposed only in the second recess 12, or may be disposed so as to extend from the second recess 12 to the second portion 133 of the light guiding member 10. The light-transmissive member 6 may be the same as the light-transmissive joining member 4 described above.

[0054] (Sealing member) The sealing members 7 and 9 are light-reflective members disposed opposite the lower surface 102 of the light-guiding member 10. The sealing members 7 and 9 are disposed so as to be in contact with the lower surface 102 of the light-guiding member 10, or so as to be in indirect contact with the lower surface 102 of the light-guiding member 10 via a bonding member or the like. The sealing member 7 is disposed so as to be in contact with the light source 1, or is disposed via a bonding member or the like. The sealing member 7 is preferably light-reflective. The light-reflective sealing member 7 has a reflectance of 60% or more, preferably 90% or more, for the light emitted from the light source 1. As the material of the light-reflective sealing member 7, a resin member containing a large number of bubbles in a light-transmitting resin material can be used. Alternatively, as the sealing member 7, a white resin member containing a light-diffusing agent in a light-transmitting resin material can be used. As the light-diffusing agent, for example, TiO2, SiO2, Al2O3, ZrO2, ZnO, etc. can be used. Examples of the resin material contained in the sealing member 7 include thermoplastic resins such as acrylic, polycarbonate, cyclic polyolefin, polyethylene terephthalate, and polyester, and thermosetting resins such as epoxy and silicone. In particular, silicone resin containing TiO2 or polyethylene terephthalate containing bubbles is preferable.

[0055] The sealing member 7 is preferably disposed around the light source 1, and covers a part or all of the lower surface 102, the first side surface B1, the second side surface B2, the third side surface B3, the fourth side surface B4, and the fifth side surface B5 of the light guide member 10. By disposing the sealing member 7, the light emitted from the light emitting device can be efficiently guided to the upper surface of the light guide member 10 with good brightness. In addition, the light source 1 and the light guide member 10 can be reinforced. The sealing member 7 and the light guide member 10 may be covered with an air layer therebetween, or may be covered by being in direct contact with each other.

[0056] [Modification of the Light Emitting Module] 4A, the light-emitting module 41 includes a light-guiding member 40 and a light source 1. The light-emitting module 41 has substantially the same configuration as the light-emitting module 20 described above, except that the shape of the light-guiding member is partially different.

[0057] (Light guiding components) 4C , the light-guiding member 40 has an upper surface 401 that serves as a light-emitting surface, and a lower surface 402 opposite to the upper surface 401. A first recess 11 is arranged on the upper surface 401, and a second recess 12 is arranged on the lower surface 402. The lower surface 402 further has inclined surfaces 43 at positions sandwiching the second recess 12 in a cross-sectional view. The light-guiding member 40 has substantially the same configuration as the light-guiding member 40 described above, except that the shape of the inclined surfaces 43 is different.

[0058] In this embodiment, the inclined surface 43 has a first region 431, a second region 432, and a third region 433 disposed between the first region 431 and the second region 432, as shown in FIG. 4B etc.

[0059] The first region 431 of the light guide member has a shape including a curve and / or a straight line arranged above a first virtual line connecting the first upper end and the first lower end at the shortest distance in a cross-sectional view. In other words, the first region 431 is configured with a concave curve that is concave toward the upper surface 401 side. The third region 433 has a shape including a curve and / or a straight line arranged above a virtual line connecting its upper end (i.e., the lower end of the second region) and its lower end (i.e., the upper end of the first region) at the shortest distance in a cross-sectional view. In other words, it is configured with a concave curve that is concave toward the upper surface 401 side. The second region 432 has a shape including a curve and / or a straight line arranged above a second virtual line connecting the second upper end and the second lower end at the shortest distance in a cross-sectional view. In other words, the second region 432 is configured with a convex curve or a straight line that is convex toward the upper surface 401 side.

[0060] The first region 431 has a first upper end 431U between the lower end of the second side surface 12b of the second recess 12 and the second bottom 12a in the vertical direction. The first upper end 431U is disposed at the uppermost position in the first region 431. The third region 433 is disposed at a position higher than the first region 431 in the vertical direction. The third region 433 has a third upper end 433U between the lower end of the second side surface 12b of the second recess 12 and the second bottom 12a in the vertical direction. The third upper end 433U is disposed at the uppermost position in the third region 433. The second region 432 has a second upper end 432U above the third upper end 433U. The second upper end 432U is disposed at the uppermost position in the second region 432. Furthermore, the second region 432 is disposed above the third upper end 433U of the third region 433 in the vertical direction. The first upper end 431U is preferably located at the outermost position of the first region 431. The third upper end 433U is preferably located at the outermost position of the third region 433. The second upper end 432U is preferably located at the outermost position of the second region 432.

[0061] It is preferable that the entire third region 433 is located above the first region 431. It is preferable that the entire second region 432 is located above the first region 431 and the third region 433. With such an arrangement, the light emitted from the light emitting device can be efficiently guided to the upper surface, which is the light emitting surface.

[0062] It is preferable that the height of the first region 431 to the first upper end 431U located on the uppermost side (height T11 in FIG. 4C ) is smaller than the depth H12 of the second recess 12. For example, the height T11 may be 12.5% ​​or more and 40% or less of the depth H12 of the second recess 12.

[0063] The rising angle (α11 in FIG. 4A) of the inclination at the edge of the first region 431 closest to the second recess 12 can be 90 degrees or more and 160 degrees or less. By setting the first region 431 to such a rising angle on the second recess side, the light emitted from the light source can be effectively dispersed within the light guiding member. Note that, on the side of the first region 431 farther from the second recess 12, the rising angle can be, for example, 0.1 degrees or more and 20 degrees or less from the plane perpendicular to the optical axis, and preferably 1 degree or more and 8 degrees or less.

[0064] 4B, the first region 431 is disposed such that the width from the center of the second recess 12 to the upper end of the first region 431 is equal in the 360-degree direction in top view. With this arrangement, the light emitted from the light source can be efficiently guided to the upper surface, which is the light-emitting surface.

[0065] The third region 433 has a height to a third upper end 433U located on the uppermost side (height T13 in FIG. 4C) of 17.5% to 110% of the depth H12 of the second recess 12. The rising angle (α13 in FIG. 4A) of the inclination at the edge of the third region 433 closest to the second recess 12 can be 90 degrees or more and 160 degrees or less. By setting the third region 433 to such a rising angle on the second recess side, the light emitted from the light source can be effectively dispersed within the light guiding member. Note that, on the side of the third region 433 farther from the second recess 12, the rising angle can be, for example, 1 degree or more and 60 degrees or less from the plane perpendicular to the optical axis, and preferably 1 degree or more and 40 degrees or less.

[0066] As shown in FIG. 4B, the third region 433 has a different width from the center of the second recess 12 to the upper end of the first region 431 in a top view. For example, when the shape of the light guide member in a top view is a rectangle, it is preferable that the width is widest between the center of the light guide member and the corner, and is narrowest between the center of the light guide member 10 and the center of the side of the light guide member in a top view. For example, as shown in FIG. 4D, the distance between the first upper end 431U of the light guide member 40 and the edge U2 (the first lower end of the first region) which is the lower end of the inclined surface 43 in a top view can be 5% to 15% of the length H0 of one side of the light guide member 10. The distance between the first upper end 431U and the third upper end 433U can be 10% to 30% of the length H0 of one side of the light guide member 10. The distance between the third upper end 433U and the second upper end 432U located on the straight line L2 passing through the center of the light-guiding member 40 and a corner of the light-guiding member 40 can be 15% to 45% of the length H0 of one side of the light-guiding member 10. As shown in Fig. 4B, the third upper end 433U of the third region 433 may change in a curved manner in top view, or may change linearly (see the light-guiding member 10A in Fig. 1C). With such a shape, the light emitted from the light source can be efficiently guided to the upper surface, which is the light-emitting surface.

[0067] The second region 432 has a height to a second upper end 432U located on the uppermost side (height T12 in FIG. 4C) of 50% or more and 350% or less of the depth H12 of the second recess 12.

[0068] For example, the angle (α12 in FIG. 4A) between the second region 432 and the lower surface is 100 degrees or more and 150 degrees or less. The height (T12 in FIG. 4C) from the second portion 434 to the second upper end 432U is preferably greater than the depth H12 of the second recess 12. For example, the height T12 is 80% or more and 500% or less of the depth of the second recess, and preferably 120% or more and 400% or less.

[0069] Embodiment 2 [Light emitting module 50] As shown in FIG. 5, the light emitting module 50 according to the second embodiment differs from the first embodiment in that the hole disposed in the light guiding member 54 is a through hole 51. The through hole 51 penetrates the light guiding member 54 from the upper surface 54a to the lower surface 54b. That is, the through hole 51 opens to both the upper surface 54a and the lower surface 54b. In the second embodiment, the light source 1 is disposed in the through hole 51. A first light-transmitting member 52 is disposed in the through hole 51. In this embodiment, the thickness of the light guiding member 54 can be, for example, 50% to 200% of the thickness of the light source, and is preferably 80% to 100%.

[0070] Within the through-hole portion 51, the first member 52 is in contact with an inner wall surface 51a of a light guiding member 54 that defines the through-hole portion 51.

[0071] The first light reflective member 53 is disposed above the light source 1. The first light reflective member 53 can be disposed in contact with the upper surface of the light source 1. Alternatively, when the first member 52 is disposed on the upper surface of the light source 1, the first light reflective member 53 is disposed on the first member 52. The first light reflective member 53 may be disposed extending from above the first member 52 to an upper surface 54a of the light guiding member 54.

[0072] The light emitting module 50 is similar to the first embodiment except that the hole in which the light source 1 is disposed is a through-hole 51. The through-hole has a constant width in a cross section parallel to the vertical direction in FIG. 5, but the width may vary.

[0073] (First member 52) The first member 52 disposed in the through-hole portion 51 contacts the side surface of the light source 1. The first member 52 may be disposed on the upper surface of the light source 1 in the through-hole portion 51. The first member 52 may be disposed between the light source 1 and the wiring board 35. The first member 52 contacts the entire surface or a part of the inner wall surface 51a of the light guiding member 54 that defines the through-hole portion 51. The upper surface of the first member 52 may be flush with the upper surface 54a of the light guiding member 54. Alternatively, the upper surface of the first member 52 may be located lower than the upper surface of the light guiding member 54. The material of the first member 52 may be, for example, the same material as that of the light-transmitting member 6 in the first embodiment.

[0074] The light emitting modules 20, 41, and 50 according to the embodiments described above can be manufactured by a known method, such as the manufacturing method described in JP 2019-12681 A or a manufacturing method equivalent thereto.

[0075] The light-emitting modules 20, 41, and 50 can be used as a backlight for a liquid crystal display device 30, for example, as shown in Fig. 7. In this case, a diffusion sheet 31, a lens sheet 32, a lens sheet 33, a liquid crystal panel 34, and the like can be laminated on the light-emitting surface side of the light-emitting module having the light source 1 and the light-guiding member 10, 40, and 54. [Explanation of symbols]

[0076] 1 light source 1a Top surface 2 Light emitting element 3. Translucent resin material 4 Translucent bonding material 5 Covering material 6 Translucent material 7, 9 Sealing member 8, 53 First light reflective member 10, 10A, 40, 54 Light guide member 101, 401, 54a top surface 102, 402, 54b bottom surface 11 First recess 11a 1st bottom 11b 1st side 12 Second recess (hole) 12a bottom (second bottom) 12b Side (2nd side) 12U bottom end 13, 43 Slope 130U bottom end 131, 431 1st area 131U, 431U 1st top end 132, 432 2nd area 132U, 432U 2nd top end 133, 434 2nd part 433 Third area 433U 3rd upper end 14 Part 1 20, 41, 50 Light emitting module 30 Liquid crystal display device 31 Diffusion Sheet 32 Lens sheet 33 Lens sheet 34 Liquid crystal panel 35 Wiring board 51 Through hole 51a Inner wall 52 First member

Claims

1. a light guide member including an upper surface serving as a light emitting surface, a lower surface opposite to the upper surface, and a hole opening on the lower surface side; A light source disposed in the hole; a first light reflective member disposed above the light source; the lower surface of the light guide member has an inclined surface surrounding the hole and positioned outside the first light reflective member in a top view, The inclined surface is a first region disposed between a first upper end located below an upper surface of the light source and a first lower end located below the first upper end on a side closer to the hole than the first upper end; a second region that is disposed between a second upper end located above the first upper end and a second lower end located below the second upper end on a side closer to the hole than the second upper end and that is disposed outside the first region in a top view, a cross-sectional shape of the first region includes a curve and / or a straight line that is located above a first virtual line that connects the first upper end and the first lower end at a shortest distance, a cross-sectional shape of the second region includes a curve and / or a straight line that is located above a second virtual line that connects the second upper end and the second lower end at a shortest distance, The first region and the second region are adjacent to each other.

2. The light emitting module according to claim 1 , wherein the hole is a bottomed hole having an opening on the lower surface side of the light guiding member, and the first light reflective member is disposed on the upper surface of the light guiding member.

3. The light-emitting module according to claim 2 , wherein the bottomed hole portion has a side surface and a bottom, and the first upper end is located below the bottom.

4. The light emitting module according to claim 3 , wherein a height from a lower end of the bottomed hole to the first upper end of the first region is equal to or greater than 12.5% ​​and equal to or less than 40% of a depth of the bottomed hole.

5. The light-emitting module according to claim 1 , wherein the hole portion is a through-hole portion having openings on the upper surface and the lower surface of the light-guiding member, and the first light-reflective member is positioned above the light source within the through-hole portion.

6. The light emitting module according to claim 1 , wherein the light guiding member is rectangular in a top view, and the first region is widest between a center of the light guiding member and a corner of the light guiding member.

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