Optical member, light source module, liquid crystal display device

Abstract

To provide an optical member which can reduce luminance unevenness when the optical member is disposed above a light source.SOLUTION: An optical member has a plurality of light control parts. Each of the light control parts has a top surface being a curved convex surface, and a bottom surface opposite to the top surface. The bottom surface includes a flat first surface, and a concave surface extending outward from the first surface and downward from an outer periphery of the first surface, and concaved outward from a virtual line connecting the outer periphery of the first surface and a lower end of the concave surface. The convex surfaces of the adjacent light control parts are directly connected to each other.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to an optical member, a light source module, and a liquid crystal display device. [Background technology]

[0002] A vehicle lamp is disclosed that comprises a substrate on which multiple LED chips are mounted and a lens section with multiple lens cutouts corresponding to the LED chips. In this vehicle lamp, the lens cutout has outer and inner surfaces that are concentric spheres centered on the junction of the LED chip. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Utility Model Application Publication No. 61-39803 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure aims to provide an optical member that can reduce brightness unevenness when placed above a light source, a light source module including the optical member, and a liquid crystal display device including the light source module. [Means for solving the problem]

[0005] An optical element according to one embodiment of the present disclosure has a plurality of light control units, each of which has an upper surface that is a curved convex surface and a lower surface opposite the upper surface, and the lower surface includes a flat first surface and a concave surface that extends downward from the outer periphery of the first surface and is recessed outward from an imaginary line connecting the outer periphery of the first surface and the lower end of the concave surface, and the convex surfaces of adjacent light control units are directly connected to each other.

[0006] A light source module according to one embodiment of the present disclosure includes a surface light source having a substrate and a plurality of light sources arranged on the substrate, and an optical element according to one embodiment of the present disclosure arranged above the light sources.

[0007] A liquid crystal display device according to an embodiment of the present disclosure includes a light source module according to an embodiment of the present disclosure. [Effects of the Invention]

[0008] According to an embodiment of the present disclosure, it is possible to provide an optical member that can reduce brightness unevenness when disposed above a light source, a light source module including the optical member, and a liquid crystal display device including the light source module. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 2 is a schematic perspective view illustrating the optical member according to the first embodiment. [Figure 2] 1A and 1B are schematic top views illustrating an optical member according to a first embodiment. [Figure 3] FIG. 2 is a schematic bottom view illustrating the optical member according to the first embodiment. [Figure 4] 4 is a schematic cross-sectional view taken along line IV-IV in FIG. 2, illustrating the optical member according to the first embodiment. [Figure 5] 10 shows the results of a simulation of the optical path of light incident on the light control unit. [Figure 6] FIG. 10 is a diagram (part 1) illustrating the cross-sectional shape of a light control section when the exit surface is rectangular. [Figure 7] FIG. 7 is a perspective view of the light control unit shown in FIG. [Figure 8] FIG. 10 is a diagram (part 2) illustrating the cross-sectional shape of the light control section when the exit surface is rectangular. [Figure 9] FIG. 9 is a perspective view of the light control unit shown in FIG. 8. [Figure 10] FIG. 2 is a schematic top view illustrating a surface light source. [Figure 11]1 is a schematic top view illustrating a light source module including a surface light source and an optical member; [Figure 12] 12 is a schematic cross-sectional view taken along line XII-XII in FIG. 11, illustrating a light source module including a surface light source and an optical member. [Figure 13] 10A and 10B are diagrams illustrating the distance between a light control unit and a light source. [Figure 14] 3 is a schematic cross-sectional view illustrating a light source mounted in a surface light source. FIG. [Figure 15] FIG. 10 is a schematic partial cross-sectional view (part 1) showing another example of the light source module. [Figure 16] FIG. 10 is a schematic partial cross-sectional view (part 2) showing another example of the light source module. [Figure 17] 1 is a partial cross-sectional view illustrating a liquid crystal display device having a light source module. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, a description will be given of an embodiment of the invention with reference to the drawings. In the following description, terms indicating specific directions or positions (e.g., "upper," "lower," and other terms including these terms) will be used as necessary. However, the use of these terms is intended to facilitate 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. Furthermore, parts that appear with the same reference numerals in multiple drawings indicate the same or equivalent parts or components.

[0011] Furthermore, in this disclosure, polygons such as triangles and quadrilaterals are referred to as polygons, including shapes in which the corners of the polygons have been processed, such as by rounding, chamfering, corner removal, or rounding. Shapes in which processing has been applied not only to the corners (edges of the sides) but also to the middle portions of the sides are also referred to as polygons. In other words, shapes in which partial processing has been applied while retaining the polygon as a base are included in the interpretation of "polygon" described in this disclosure.

[0012] The same applies to words that represent specific shapes, such as trapezoids, circles, and irregularities, not just polygons. The same also applies when dealing with the sides that form the shape. In other words, even if the corners or middle part of a side have been processed, the interpretation of "side" includes the processed part. Note that when distinguishing a "polygon" or "side" that has no processing from a processed shape, the word "strict" is added, for example, "strict quadrangle."

[0013] Furthermore, the embodiments shown below are intended to exemplify optical components and the like embodying the technical concepts of the present invention, and are not intended to limit the scope of the present invention. Furthermore, unless otherwise specified, the dimensions, materials, shapes, relative positions, and the like of the components described below are intended for illustrative purposes only and are not intended to limit the scope of the present invention. Furthermore, the content described in one embodiment may also be applied to other embodiments and modified examples. Furthermore, the sizes and positional relationships of components shown in the drawings may be exaggerated for clarity. Furthermore, to avoid overly complex drawings, schematic diagrams may be used in which some elements are omitted, or end views may be used as cross-sectional views showing only the cut surface.

[0014] First Embodiment (Optical component 1) Fig. 1 is a schematic perspective view illustrating an optical member according to a first embodiment. Fig. 2 is a schematic top view illustrating an optical member according to the first embodiment. Fig. 3 is a schematic bottom view illustrating an optical member according to the first embodiment. Fig. 4 is a schematic cross-sectional view taken along line IV-IV in Fig. 2, illustrating the optical member according to the first embodiment. For reference, Figs. 1 to 4 show an X-axis, a Y-axis, and a Z-axis that are orthogonal to each other.

[0015] As shown in FIGS. 1 to 4, the optical member 1 has a plurality of light control units 10. In the examples of FIGS. 1 to 4, the light control units 10 are arranged two-dimensionally in a matrix of 5 rows and 9 columns. The X-axis direction is the row direction, and the Y-axis direction is the column direction. In other words, the light control units 10 are arranged so that their centers are located at the centers of square lattice points. The light control units 10 are arranged, for example, at a constant pitch in the X-axis and Y-axis directions. The arrangement of the light control units 10 is not limited to the examples of FIGS. 1 to 4. For example, the light control units 10 may be arranged so that their centers are located at the centers of hexagonal lattice points.

[0016] Each light control unit 10 has a curved convex surface 11 that serves as the upper surface, and a lower surface 12 opposite the upper surface. The lower surface 12 includes a flat first surface 121 and a concave surface 122. The concave surface 122 extends downward from the outer periphery of the first surface 121. The concave surface 122 is recessed outward from an imaginary line V that connects the outer periphery of the first surface 121 and the lower end of the concave surface 122.

[0017] The convex surface 11 curves in a direction away from the lower surface 12. In other words, the convex surface 11 is arc-shaped in a cross-sectional view. In a top view, the convex surface 11 is, for example, quadrangular. In a top view, the convex surface 11 may be square or rectangular. In the example of FIGS. 1 to 4, the convex surface 11 is square in a top view. In a top view, the length of one side of the convex surface 11 is, for example, 1 mm or more and 20 mm or less. The convex surfaces 11 of adjacent light control units 10 are directly connected to each other. In other words, there is no flat surface or the like between the convex surfaces 11 of adjacent light control units 10.

[0018] In top view, the lower surface 12 overlaps with the convex surface 11. In top view, the first surface 121 is, for example, circular. Whether the convex surface 11 is square or rectangular in top view, the first surface 121 can be circular. For example, the first surface 121 is a plane parallel to the horizontal plane when the optical member 1 is placed on a horizontal plane with the lower surface 12 side facing down. Here, the horizontal plane is a plane parallel to a plane containing the X-axis and the Y-axis. In top view, the concave surface 122 is, for example, frame-shaped with a circular inner edge and a rectangular outer edge. Note that the term "circular" here includes a perfect circle, an ellipse, and a shape forming a ring that is symmetrical in both the left and right and top and bottom directions.

[0019] 1 to 4, the lower ends of the concave surfaces 122 of adjacent light control units 10 are directly connected to each other. However, a connecting surface that connects the lower ends of the concave surfaces 122 of adjacent light control units 10 may be interposed. In this case, the connecting surface may be, for example, a plane parallel to the first surface 121.

[0020] In Fig. 4, line A is a line connecting the center of first surface 121 and the center of convex surface 11 in top view, and is the optical axis of light control unit 10. Line A is parallel to the Z axis. That is, in the example of Fig. 4, the center of first surface 121 coincides with the center of convex surface 11 in top view. Note that "the centers coincide in top view" refers to a case where the distance between the centers of the objects to be compared is 0.1 mm or less in top view.

[0021] The light control units 10 can be made of a material such as polycarbonate resin, acrylic resin, cycloolefin polymer (COP), or silicone resin. The pitch of the light control units 10 can be, for example, 1 mm or more and 20 mm or less. Here, the pitch refers to the distance between the centers of two adjacent light control units 10. The light control units 10 can be made, for example, by molding. When the optical member 1 has a frame unit 20, the frame unit 20 can be made integrally with the light control units 10 using the same material, for example.

[0022] As described above, each light control section 10 of the optical element 1 has a convex surface 11 and a lower surface 12 including a flat first surface 121 and a concave surface 122. The convex surfaces 11 of adjacent light control sections 10 are directly connected to each other. This improves the uniformity of the light emitted from the optical element 1 when the optical element 1 is used in combination with a light source and the light control section 10 is disposed above the light source (see, for example, FIG. 12 described below). Improving the uniformity of light is essentially synonymous with reducing brightness unevenness. Hereinafter, the reduction of brightness unevenness will be described in detail.

[0023] Fig. 5 shows the results of a simulation of the optical path of light incident on the light control unit. Fig. 5 shows a case where the light control unit 10X is used as Comparative Example 1, a case where the light control unit 10Y is used as Comparative Example 2, and a case where the light control unit 10 is used as an example. Note that the configuration in Fig. 5 shows a vertical cross section cut along the diagonal of the convex surface 11 of each light control unit.

[0024] The light control unit 10X, the light control unit 10Y, and the light control unit 10 have different shapes of the lower surface, which is the light incident surface. The light control unit 10X has a lower surface that is composed only of a flat surface. The light control unit 10Y has a lower surface that is composed only of a concave surface. As described above, the light control unit 10 has a lower surface that is composed of a flat surface and a concave surface.

[0025] In FIG. 5, in each of light control units 10X, 10Y, and 10, the distance H from the light-emitting surface of light source 520 to the bottom edge of the bottom surface of the light control unit is 4.2 mm. Light with a Lambertian distribution enters each light control unit from the bottom surface of light source 520 arranged on substrate 510, travels along the optical path indicated by the arrows, exits convex surface 11, and then passes through diffusion sheet 530. The length of the arrows above diffusion sheet 530 schematically indicates the intensity of the light, with crosses indicating particularly dark areas. In addition to the configuration of each light control unit, FIG. 5 also shows the luminance distribution and uniformity of the light passing through diffusion sheet 530. Here, uniformity refers to the ratio of the lowest luminance to the highest luminance in the luminance distribution; the higher this value, the better the uniformity.

[0026] In the light control unit 10X according to Comparative Example 1, light incident on the outer periphery of the lower surface, indicated by the dashed lines, is refracted at the lower surface toward the center of the convex surface 11, and a portion of it is totally reflected when it reaches the outer periphery of the convex surface 11. As a result, the light above the outer periphery of the convex surface 11 is reduced, and the area indicated by the cross becomes dark. As a result, the brightness unevenness of the light emitted from the convex surface 11 is very large, with a uniformity of 0.3%.

[0027] In the light control unit 10Y according to Comparative Example 2, the lower surface is not flat but concave, and therefore, unlike the light control unit 10X, light incident on the outer periphery of the concave surface is less likely to refract toward the center of the convex surface 11. Therefore, light reaching the outer periphery of the convex surface 11 is less likely to be totally reflected, improving the brightness of the region indicated by an "x" in the light control unit 10X. However, because the entire light incident surface is concave, more light is scattered by the concave surface, reducing the light-collecting ability of the convex surface 11. For example, the light indicated by the dashed line is not collected, and less light reaches the region indicated by an "x" above the convex surface 11, resulting in darkness. As a result, the brightness unevenness of the light emitted from the convex surface 11 was not sufficiently improved, with a uniformity of 45.2%.

[0028] In the light control unit 10 according to the example, the luminance distribution was significantly improved, with a uniformity of 73.5%, compared to Comparative Examples 1 and 2. This is the result of reducing the total reflection that occurs on the outer periphery of the convex surface 11 by providing a concave surface on the outer periphery of the lower surface, and reducing the scattering of light incident on the flat surface by providing a flat surface on the center of the lower surface, thereby maintaining the light-collecting ability of the convex surface 11.

[0029] FIG. 6 is a diagram (part 1) for explaining the cross-sectional shape of the light control section when the convex surface is rectangular. In FIG. 6, the upper right is a top view. The upper left is a vertical cross section (for convenience, referred to as the first cross section) cut through the center of the rectangular convex surface 11 and parallel to the short side. The lower right is a vertical cross section (for convenience, referred to as the second cross section) cut through the center of the rectangular convex surface 11 and parallel to the long side. FIG. 7 is a perspective view of the light control section shown in FIG. 6.

[0030] 6 and 7, in top view, the convex surface 11 is a rectangle with short and long sides. The radius of curvature of the convex surface 11 is the same in the first cross section and the second cross section. The height from the lower end of the concave surface 122 of the portion where the convex surfaces 11 of adjacent light control units 10 meet is H2 in the second cross section, which is lower than H1 in the first cross section.

[0031] 6 and 7, the shape of the light control units 10 is not changed between the first cross section and the second cross section, and the spacing between the light control units 10 in the second cross section is wider than the spacing between the light control units 10 in the first cross section. Even when the convex surface 11 is rectangular, by making it have the shape shown in Figures 6 and 7, it is possible to improve the uniformity of the light emitted from the optical member and reduce uneven brightness, just as in the case when the convex surface 11 is square.

[0032] FIG. 8 is a diagram (part 2) for explaining the cross-sectional shape of the light control section when the convex surface is rectangular. In FIG. 8, the upper right is a top view. The upper left is a vertical cross section (for convenience, referred to as the first cross section) cut through the center of the rectangular convex surface 11 and parallel to the short side. The lower right is a vertical cross section (for convenience, referred to as the second cross section) cut through the center of the rectangular convex surface 11 and parallel to the long side. FIG. 9 is a perspective view of the light control section shown in FIG. 8.

[0033] 8 and 9, in top view, the convex surface 11 is a rectangle with short and long sides. The radius of curvature of the convex surface 11 is larger in the second cross section than in the first cross section. Furthermore, the height H1 from the lower end of the concave surface 122 at the portion where the convex surfaces 11 of adjacent light control units 10 meet is the same in the first cross section and the second cross section.

[0034] 8 and 9 show different shapes of the light control sections 10 in the first cross section and the second cross section. This shape is effective when the aspect ratio of the long side to the short side of the convex surface 11 becomes large and cannot be addressed by simply widening the spacing between the light control sections 10 as in Figures 6 and 7. Even when the convex surface 11 is rectangular, by using the shapes shown in Figures 8 and 9, the uniformity of the light emitted from the optical member can be improved and brightness unevenness can be reduced, just like when the convex surface 11 is square.

[0035] (light source module 300) Here, a light source module including a surface light source and an optical member will be described. First, the surface light source will be described. Fig. 10 is a schematic top view illustrating an example of a surface light source. The surface light source 200 shown in Fig. 10 includes a substrate 210 and a plurality of light sources 280 arranged on the substrate 210. The plurality of light sources 280 are arranged, for example, two-dimensionally in a matrix on the substrate 210.

[0036] Fig. 11 is a schematic top view illustrating a light source module including a surface light source and an optical member. Fig. 12 is a schematic cross-sectional view taken along line XII-XII in Fig. 11 illustrating a light source module including a surface light source and an optical member.

[0037] 11 and 12, the light source module 300 includes a surface light source 200 and an optical member 1 disposed above a light source 280 of the surface light source 200. The surface light source 200 and the optical member 1 are held in a housing so as to have a predetermined positional relationship, for example.

[0038] 11 and 12, in the light source module 300, the number of light sources 280 is equal to the number of light control units 10. In a top view, each light source 280 overlaps with the first surface 121 of the light control unit 10 located above the light source 280. Note that, in a top view, the light source 280 overlapping with the first surface 121 of the light control unit 10 means that, in a top view, the light-emitting surface of the light source 280 overlaps with the first surface 121 of the light control unit 10. In addition, in a top view, it is preferable that the center of the light source 280 coincides with the center of the first surface 121.

[0039] 12, pitch P1 is the distance in the X-axis direction connecting the centers of two adjacent light sources 280 in top view. Pitch P2 is the distance in the X-axis direction connecting the centers of two adjacent light control units 10 in top view. In the X-axis direction of the light source module 300, pitch P1 of the light sources 280 is preferably equal to pitch P2 of the light control units 10. Furthermore, in the Y-axis direction of the light source module 300, pitch of the light sources 280 is preferably equal to pitch of the light control units 10. This makes it easier for the entire light emitted from the light sources 280 to be irradiated onto the lower surface 12, thereby improving light utilization efficiency.

[0040] In the light source module 300, the number of light sources 280 may be less than the number of light control units 10. For example, the light source 280 may be a light source having a light-emitting surface divided into a plurality of regions. In this case, too, the light source 280 overlaps with the first surface 121 of the light control unit 10 in top view. That is, the light-emitting surface of each light source 280 overlaps with the first surface 121 of the light control unit 10 in top view.

[0041] In the light source module 300, light emitted from the light source 280 travels vertically and diagonally upward from the light source 280 and is incident on the lower surface 12 of the light control unit 10 located above the light source 280. The light incident on the lower surface 12 is collected by the light control unit 10 and emitted from the convex surface 11 to the outside of the light source module 300.

[0042] Fig. 13 is a diagram illustrating the distance between the light control unit and the light source. Fig. 13 schematically shows how light from the light source enters light control unit 10 and exits from light control unit 10, and how light from light control unit 10 enters diffusion sheet 530 and exits from diffusion sheet 530. In Fig. 13, a substantially V-shaped dashed line indicates the light distribution angle from light source 520 to light control unit 10. The thickness of the arrow passing through light control unit 10 also schematically indicates the intensity of light. The length of the arrow above diffusion sheet 530 also schematically indicates the intensity of light.

[0043] 13, if the light control unit 10 and the light source 520 are too close, the light distribution angle from the light source 520 to the light control unit 10 becomes wide, and a lot of weak light with a large incident angle from the light source 520 enters the outer periphery of the light control unit 10. As a result, less light enters the diffusion sheet 530 in a direction perpendicular to the outer periphery of the light control unit 10, reducing the uniformity of the light emitted from the diffusion sheet 530 and increasing brightness unevenness. In addition, it is difficult to collimate the light emitted from the light control unit 10.

[0044] In contrast, as in the configuration shown on the right side of Fig. 13, when the distance between the light control unit 10 and the light source 520 is appropriate, the light distribution angle from the light source 520 to the light control unit 10 narrows, and weak light from the light source 520 does not enter the outer periphery of the light control unit 10. By discarding the weak light from the light source 520 in this way, weak light is less likely to enter the diffusion sheet 530 from the outer periphery of the light control unit 10, improving the uniformity of the light emitted from the diffusion sheet 530 and reducing brightness unevenness. In addition, it is easy to collimate the light emitted from the light control unit 10.

[0045] When the convex surface 11 is square or rectangular in top view, as shown in FIGS. 11 and 12 , where L is the length of one side of the square or the short side of the rectangle, and H is the distance between the light-emitting surface of the light source 280 and the bottom end of the concave surface 122 in a direction perpendicular to the first surface 121, L and H preferably satisfy the relationship 0.19×L<H<0.19×L+3.0. For example, 0.7<H<5.0 may be satisfied. Furthermore, when W is the length of one side of the square or the short side of the rectangle, L and W preferably satisfy the relationship 0.4×L-0.19<W<0.5×L+1.02. For example, 0.7<W<6.0 may be satisfied. By satisfying these relationships, the distance between the optical member and the light source becomes appropriate, as shown on the right side of FIG. 13 , thereby significantly achieving the above-mentioned effects. The shape of the light-emitting surface of the light source 280 may be appropriately adjusted to a square or rectangle to match the shape of the light control unit.

[0046] Here, the members included in the surface light source 200 will be described in detail.

[0047] (Substrate 210) The substrate 210 is a member for mounting a plurality of light sources 280. On the upper surface of the substrate 210, conductor wiring for supplying power to the light sources 280 is arranged.

[0048] Examples of the base material of the substrate 210 include ceramics, resin, composite materials, etc. Examples of resin include phenolic resin, epoxy resin, polyimide resin, BT resin, polyphthalamide (PPA), polyethylene terephthalate (PET), etc. Examples of composite materials include the above-mentioned resins mixed with glass fiber, silicon oxide, titanium oxide, aluminum oxide, etc., and metal substrates in which a metal member is coated with an insulating layer.

[0049] The thickness of the substrate 210 can be selected appropriately. The substrate 210 may be either a flexible substrate that can be manufactured by a roll-to-roll method or a rigid substrate. The rigid substrate may be a thin rigid substrate that can be bent.

[0050] Preferably, a light-reflecting member 220 is provided on the upper surface of the substrate 210 around the light source 280. The light-reflecting member 220 is preferably made of an insulating material. For example, the material of the light-reflecting member 220 may be at least one of a resin exemplified as the material of the substrate 210 mixed with a filler such as barium titanate, titanium oxide, aluminum oxide, silicon oxide, or zinc oxide, or a resin exemplified as the material of the substrate 210 containing a plurality of fine bubbles.

[0051] By providing the light reflective member 220 on the upper surface of the substrate 210, when the light source module 300 is configured with the surface light source 200 and the optical member 1, light emitted upward from the light source 280 and reflected downward by the optical member 1 is reflected upward again by the light reflective member 220 and enters the optical member 1. As a result, the light extraction efficiency of the light source module 300 can be improved.

[0052] (Light source 280) 14 is a schematic cross-sectional view illustrating a light source mounted in a surface light source. The light source 280 is, for example, rectangular in top view, but may be circular or the like. The top surface of the light source 280 is a light-emitting surface.

[0053] 14, light source 280 is a light emitting device including leads, a resin molded body, and a light emitting element. In the light emitting device, for example, a pair of plate-shaped leads 281 are partially embedded in resin molded body 283. Resin molded body 283 and the pair of leads 281 form a support body, and the support body has a recess defined by a bottom surface and side surfaces. The bottom surface defining the recess is formed by resin molded body 283 and a portion of the pair of leads 281, and the side surfaces have reflective surfaces with a predetermined inclination angle.

[0054] The space between the pair of leads 281 is filled with a resin molding 283, which constitutes part of the bottom surface that defines the recess. The resin molding 283 is, for example, rectangular in top view. Parts of the pair of leads 281 are exposed on the bottom surface of the resin molding 283 as external terminals. In the light emitting device, a light emitting element 282 may be placed in the recess, and the light emitting element 282 may be covered with a sealing member 285.

[0055] The base material constituting the lead 281 may be, for example, a plate-like body containing at least one metal selected from copper, aluminum, gold, silver, tungsten, iron, and nickel, or an alloy or clad material such as an iron-nickel alloy or phosphor bronze. A film (e.g., a plated film) containing silver, aluminum, gold, or an alloy thereof may be formed on the surface of the lead 281 in order to efficiently extract light from the light-emitting element 282. The metal film formed on the surface of the lead 281 may be a single-layer film or a multi-layer film.

[0056] The resin molded body 283 can be made of a resin containing a thermosetting resin or a thermoplastic resin. In particular, it is preferable to use a thermosetting resin. The thermosetting resin is preferably a resin with lower gas permeability than the resin used for the sealing member 285, and specific examples of the thermosetting resin include epoxy resin, silicone resin, modified epoxy resin such as silicone-modified epoxy resin, modified silicone resin such as epoxy-modified silicone resin, polyimide resin, modified polyimide resin, urethane resin, and modified urethane resin. The resin molded body 283 may contain glass fiber, titanium oxide, aluminum oxide, silicon oxide, etc.

[0057] The light emitting element 282 is placed on, for example, the bottom surface that defines the recess. The light emitting element 282 is fixed to the lead 281 by, for example, a bonding member. The light emitting element 282 has a pair of positive and negative electrodes, which are electrically connected to the pair of leads 281 via wires, respectively. Power can be supplied from an external source via the pair of leads 281 to cause the light source 280 to emit light.

[0058] The light-emitting element 282 is preferably, for example, a light-emitting diode. The light-emitting element 282 can be selected from those with any wavelength. The light-emitting element 282 emits, for example, blue, green, or red light. The light-emitting element 282 has a semiconductor stack. The semiconductor stack includes an n-type semiconductor layer, a p-type semiconductor layer, and a light-emitting layer sandwiched between them. The light-emitting layer may have a structure such as a double heterojunction or a single quantum well (SQW), or a structure with a group of active layers such as a multiple quantum well (MQW). The semiconductor stack may include multiple light-emitting layers. For example, the semiconductor stack may have a structure including two or more light-emitting layers between an n-type semiconductor layer and a p-type semiconductor layer, or may have a structure in which a structure including an n-type semiconductor layer, a light-emitting layer, and a p-type semiconductor layer in that order is repeated multiple times. When the semiconductor stack includes multiple light-emitting layers, the emission peak wavelengths may differ among the multiple light-emitting layers, or the semiconductor stack may include light-emitting layers with the same emission peak wavelength. The light emitting element 282 can be made of a nitride semiconductor such as GaN, InGaN, AlGaN, or AlInGaN. Furthermore, the red light emitting element can be made of GaAlAs, AlInGaP, or the like. Furthermore, semiconductor light emitting elements made of other materials may also be used. The composition, light emitting color, size, number, and other factors of the light emitting elements used can be appropriately selected depending on the purpose.

[0059] The light emitting element 282 is covered with a light-transmitting sealing member 285. A resin having excellent heat resistance, weather resistance, and light resistance is preferably used as the sealing member 285. Examples of such resins include silicone resin, modified silicone resin, epoxy resin, modified epoxy resin, urea resin, phenol resin, acrylic resin, urethane resin, or fluororesin, or a resin containing two or more of these resins.

[0060] To provide a predetermined function, the sealing member 285 can be mixed with at least one selected from the group consisting of fillers, pigments, and phosphors. Suitable fillers include barium titanate, titanium oxide, aluminum oxide, silicon oxide, and zinc oxide. The sealing member 285 may also contain organic or inorganic coloring dyes or coloring pigments to transmit light in a desired wavelength range. Furthermore, the sealing member 285 may also contain a phosphor.

[0061] When the sealing member 285 contains a phosphor, it functions as a wavelength conversion member. The wavelength conversion member absorbs at least a portion of the light emitted from the light emitting element 282 and emits light of a wavelength different from the wavelength of the light from the light emitting element 282. For example, the wavelength conversion member converts the wavelength of a portion of the blue light from the light emitting element 282 to emit yellow light. With this configuration, white light is obtained by mixing the blue light that has passed through the wavelength conversion member with the yellow light emitted from the wavelength conversion member.

[0062] The light source 280 may be a light-emitting element 282 instead of the light-emitting device shown in FIG. 14 . Here, the light-emitting element 282 may have a light-reflecting film on its upper surface. The light-reflecting film may be, for example, a metal film such as silver or aluminum, a dielectric multilayer film, a resin containing a filler such as barium titanate, titanium oxide, aluminum oxide, silicon oxide, or zinc oxide, or a combination thereof. A light-transmitting sealing member covering the light-emitting element 282 may be provided on the upper surface of the substrate 210. Examples of materials for the sealing member include light-transmitting resins such as epoxy resin, silicone resin, or a mixture thereof, glass, etc. Among these, silicone resin is preferable in view of its light resistance and ease of molding. The sealing member may contain a diffusing agent for diffusing light from the light-emitting element 282, a coloring agent corresponding to the color of light emitted by the light-emitting element 282, etc. The diffusing agent, coloring agent, etc. may be those known in the art.

[0063] (Another example of a light source module) Here, another example of a light source module including a surface light source and an optical member will be described. The light source module may include a diffusion sheet. Furthermore, the light source module may include a prism sheet when bending the optical axis. Furthermore, the light source module may include both a diffusion sheet and a prism sheet. Specific examples are shown below.

[0064] Fig. 15 is a schematic partial cross-sectional view (part 1) showing another example of a light source module. A light source module 300A shown in Fig. 15 includes a diffusion sheet 310 and a prism sheet 320 above an optical member 1 in this order.

[0065] By including diffusion sheet 310, light source module 300A can improve the uniformity of light extracted from light source module 300A to the outside. Furthermore, by including prism sheet 320, light source module 300A can change the optical axis of light extracted from light source module 300A to a predetermined direction. Note that the positional relationship between diffusion sheet 310 and prism sheet 320 may be upside down compared to that in FIG. 15 .

[0066] Fig. 16 is a schematic partial cross-sectional view (part 2) showing another example of a light source module. Light source module 300B shown in Fig. 16 differs from light source module 300A shown in Fig. 15 in that it does not include prism sheet 320. Light source module 300B shown in Fig. 16 also differs from light source module 300A shown in Fig. 15 in that it includes planar light source 200A instead of planar light source 200.

[0067] In the surface light source 200A, the optical axis of each optical member 1 and the optical axis of each light source 280 are shifted in the X-axis direction. This allows the optical axis of light extracted from the light source module 300B to be changed to a predetermined direction even without a prism sheet. Note that the optical axis of each optical member 1 and the optical axis of each light source 280 may be shifted in the Y-axis direction, or may be shifted in both the X-axis direction and the Y-axis direction.

[0068] 11 to 16, the surface light source used in the light source module is described as having a substrate, but the substrate is provided as needed and can be omitted. For example, in the light source module, a surface light source in which a plurality of light-emitting elements are integrally held by a translucent resin or the like can be used.

[0069] (Liquid crystal display device) Fig. 17 is a partial cross-sectional view illustrating a liquid crystal display device having a light source module. Liquid crystal display device 400 shown in Fig. 17 has a light source module 300A and a liquid crystal panel 410. In liquid crystal display device 400, light emitted from light source module 300A is incident on liquid crystal panel 410, and an image is displayed on liquid crystal panel 410.

[0070] Since the light emitted from the light source module 300A has a deflected angle, for example, when the liquid crystal display device 400 is incorporated into a head-up display system and the installation angle of the light source module 300A is adjusted to remove distortion of the virtual image, the effect of optical axis misalignment occurring on the virtual image side can be suppressed.

[0071] In addition, in the liquid crystal display device 400, the light source module 300 or 300B may be used instead of the light source module 300A. Furthermore, when the light source module 300 is used in the liquid crystal display device 400, a prism sheet 320 may be disposed on the opposite side of the liquid crystal panel 410 from the light source module 300.

[0072] Although the preferred embodiments have been described in detail above, the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope of the claims.

[0073] In addition to the above-described embodiments, the following supplementary notes are also disclosed. (Appendix 1) A plurality of light control units are provided, Each of the light control portions has an upper surface that is a curved convex surface and a lower surface opposite the upper surface, The lower surface is A flat first surface and a concave surface extending downward from the outer periphery of the first surface and outward from an imaginary line connecting the outer periphery of the first surface and a lower end of the concave surface, The convex surfaces of the adjacent light control portions are directly connected to each other. (Appendix 2) 2. The optical element of claim 1, wherein the convex surface is square and the first surface is circular when viewed from above. (Appendix 3) 2. The optical element of claim 1, wherein, in a top view, the convex surface is rectangular and the first surface is circular. (Appendix 4) 4. The optical element according to claim 1, wherein the center of the first surface coincides with the center of the convex surface when viewed from above. (Appendix 5) When viewed from above, the convex surface is a rectangle having a short side and a long side, When a vertical cross section cut through the center of the rectangle parallel to the short side is defined as a first cross section, and a vertical cross section cut through the center of the rectangle parallel to the long side is defined as a second cross section, An optical element according to any one of appendices 1 to 4, wherein the height from the lower end of the concave surface of the portion where the convex surfaces of adjacent light control units meet is lower in the second cross section than in the first cross section. (Appendix 6) When viewed from above, the convex surface is a rectangle having a short side and a long side, When a vertical cross section cut through the center of the rectangle parallel to the short side is defined as a first cross section, and a vertical cross section cut through the center of the rectangle parallel to the long side is defined as a second cross section, 5. The optical element according to claim 1, wherein the radius of curvature of the convex surface is larger in the second cross section than in the first cross section. (Appendix 7) a surface light source including a substrate and a plurality of light sources arranged on the substrate; and the optical member according to any one of Supplementary Notes 1 to 6, arranged above the light source. (Appendix 8) 8. The light source module according to claim 7, wherein, in a top view, the center of the light source coincides with the center of the first surface. (Appendix 9) When viewed from above, the convex surface is square or rectangular; When the length of one side of the square or the short side of the rectangle is L and the distance between the light emitting surface of the light source and the lower end of the concave surface in a direction perpendicular to the first surface is H, 9. The light source module according to claim 7, wherein L and H satisfy 0.19×L< H <0.19×L+3.0. (Appendix 10) When the length of the light emitting surface in the direction of one side of the square or the short side of the rectangle is W, 10. The light source module of claim 9, wherein L and W satisfy 0.4×L−0.19< W <0.5×L+1.02. (Appendix 11) A liquid crystal display device comprising the light source module according to any one of appendixes 7 to 10. [Explanation of symbols]

[0074] 1 Optical components 10 Optical control section 11 Convex 12 Bottom side 20 Frame 121 Page 1 122 Concave 200,200A surface light source 210 Substrate 220 Light-reflective material 280 light source 281 leads 282 Light-emitting element 283 Resin moldings 285 Sealing member 300, 300A, 300B Light Source Module 310 Diffusion Sheet 320 Prism Sheet 400 LCD display device 410 LCD panel

Claims

1. A plurality of light control units are provided, Each of the light control portions has an upper surface that is a curved convex surface and a lower surface opposite the upper surface, The lower surface is a flat first surface; a concave surface extending downward from the outer periphery of the first surface and outward from an imaginary line connecting the outer periphery of the first surface and a lower end of the concave surface, The convex surfaces of the adjacent light control portions are directly connected to each other.

2. The optical member according to claim 1 , wherein, in a top view, the convex surface is square and the first surface is circular.

3. The optical member according to claim 1 , wherein, in a top view, the convex surface is rectangular and the first surface is circular.

4. The optical member according to claim 1 , wherein a center of the first surface coincides with a center of the convex surface when viewed from above.

5. When viewed from above, the convex surface is a rectangle having a short side and a long side, When a vertical cross section cut through the center of the rectangle parallel to the short side is defined as a first cross section, and a vertical cross section cut through the center of the rectangle parallel to the long side is defined as a second cross section, The optical member according to claim 1 , wherein a height from a lower end of the concave surface of a portion where the convex surfaces of adjacent light control portions contact each other is lower in the second cross section than in the first cross section.

6. When viewed from above, the convex surface is a rectangle having a short side and a long side, When a vertical cross section cut through the center of the rectangle parallel to the short side is defined as a first cross section, and a vertical cross section cut through the center of the rectangle parallel to the long side is defined as a second cross section, The optical member according to claim 1 , wherein the radius of curvature of the convex surface is larger in the second cross section than in the first cross section.

7. a surface light source including a substrate and a plurality of light sources arranged on the substrate; A light source module comprising: the optical member according to claim 1 disposed above the light source.

8. The light source module according to claim 7 , wherein a center of the light source coincides with a center of the first surface in a top view.

9. When viewed from above, the convex surface is square or rectangular; When the length of one side of the square or the short side of the rectangle is L and the distance between the light emitting surface of the light source and the lower end of the concave surface in a direction perpendicular to the first surface is H, The light source module according to claim 7 , wherein L and H satisfy 0.19×L<H<0.19×L+3.

0.

10. When the length of the light emitting surface in the direction of one side of the square or the short side of the rectangle is W, 10. The light source module according to claim 9, wherein L and W satisfy 0.4×L−0.19<W<0.5×L+1.

02.

11. A liquid crystal display device comprising the light source module according to claim 7.

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