planar light source

Abstract

To provide a planar light source which enables reduction of luminance unevenness.SOLUTION: A planar light source includes: a support having a base material and a first wiring having a linear expansion coefficient smaller than that of the base material; and a plurality of light source groups which are disposed on the support and arranged side by side in an X direction. Each of the plurality of the light source groups has a first light source and a second light source which are disposed arranged side by side in a Y direction. The first wiring has: a first extension part located at the -X side relative to the first light source; a second extension part located between the first light source and the second light source in the Y direction; and a third extension part located at the + X side relative to the second light source.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] Embodiments of the present invention relate to a planar light source. [Background technology]

[0002] Planar light sources equipped with multiple light-emitting elements such as light-emitting diodes are widely used, for example, in the backlights of liquid crystal displays. For example, Patent Document 1 discloses a planar light source comprising multiple light source units and a wiring board on which the multiple light source units are arranged. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-056369 [Overview of the project] [Problems that the invention aims to solve]

[0004] Planar light sources require further reduction of brightness unevenness. The embodiment of the present invention aims to provide a planar light source that can reduce brightness unevenness. [Means for solving the problem]

[0005] According to one aspect of the present invention, a support comprising a base material and a first wiring having a smaller coefficient of linear expansion than the base material and arranged on a first surface of the base material, and a plurality of light source groups arranged on the support and aligned in the X direction, wherein each of the plurality of light source groups has a first light source and a second light source arranged in the Y direction perpendicular to the X direction, and the first wiring is electrically connected to at least one of the first light source and the second light source and has a first extension portion located on the -X side with respect to the first light source and extending in a first direction parallel to the Y direction, a second extension portion located between the first light source and the second light source in the Y direction and extending from a first connection portion of the first extension portion in a second direction different from the first direction, and a third extension portion located on the +X side with respect to the second light source and extending from a second connection portion of the second extension portion in the first direction. [Effects of the Invention]

[0006] According to one embodiment of the present invention, a planar light source can reduce brightness unevenness. [Brief explanation of the drawing]

[0007] [Figure 1] This is a schematic top view of the planar light source according to this embodiment. [Figure 2] This is a schematic top view of a part of the planar light source according to this embodiment. [Figure 3A] This is a schematic cross-sectional view of the light source unit according to this embodiment. [Figure 3B] This is a schematic cross-sectional view of a modified example of the light source unit according to this embodiment. [Figure 4] Figure 2 is a schematic cross-sectional view along line IV-IV. [Figure 5] This is a schematic bottom view of a part of the planar light source according to this embodiment. [Figure 6] This is a schematic bottom view of a part of the planar light source according to this embodiment. [Figure 7A] This is a schematic bottom view of a part of the first wiring according to this embodiment. [Figure 7B] This is a schematic bottom view of a modified example of the first wiring according to this embodiment. [Figure 7C] This is a schematic bottom view of a part of the first wiring according to this embodiment. [Modes for carrying out the invention]

[0008] The embodiments will be described below with reference to the drawings. Since each drawing schematically shows an embodiment, the scale, spacing, or positional relationship of each component may be exaggerated, or some components may be omitted from the illustration. In this specification, the direction of the Z-axis arrow is considered upward, and the direction opposite to the direction of the Z-axis arrow is considered downward. The side of the X-axis in the direction of the arrow is considered the +X side, and the side opposite to the direction of the X-axis arrow is considered the -X side. The side of the Y-axis in the direction of the arrow is considered the +Y side, and the side opposite to the direction of the Y-axis arrow is considered the -Y side. In addition, in some cases, an end view showing only the cut surface may be shown as a cross-sectional view.

[0009] In the following description, components having substantially the same function are indicated by common reference numerals, and their descriptions may be omitted. Furthermore, terms indicating specific directions or positions (e.g., "up," "down," and other terms including these) may be used. However, these terms are used merely for clarity to indicate the relative direction or position in the referenced drawings. If the relative direction or position relationship indicated by terms such as "up" and "down" in the referenced drawings is the same, the arrangement in drawings other than those disclosed, actual products, etc., does not have to be identical to that in the referenced drawings. In this specification, "parallel" includes not only cases where two lines, edges, planes, etc., do not intersect when extended, but also cases where the angle between two lines, edges, planes, etc., intersects within a range of 10° or less. In this specification, the positional relationship expressed as "up" includes cases where they are touching, and cases where they are not touching but are located above.

[0010] [Embodiment] The planar light source 300 of the embodiment will be described with reference to FIGS. 1 to 7C. FIG. 1 is a view seen from the light emitting surface side of the planar light source 300. As shown in FIG. 1, two directions that are parallel to the light emitting surface of the planar light source 300 and perpendicular to each other are defined as the X direction and the Y direction. The direction perpendicular to the X direction and the Y direction is defined as the Z direction. In this specification, the plane parallel to the X direction and the Y direction may be referred to as the XY plane. Further, the direction inclined at an angle of 0° or more and less than 360° from the X direction in the XY plane may be referred to as the lateral direction, and the Z direction may be referred to as the vertical direction.

[0011] The planar light source 300 includes a support 100 and a plurality of light source groups 200. The support 100 has a base material 11 and a first wiring 12A. The linear expansion coefficient of the first wiring 12A is smaller than the linear expansion coefficient of the base material 11. The base material 11 includes a first surface 111A. The first wiring 12A is disposed on the first surface 111A of the base material 11. The plurality of light source groups 200 are disposed on the support 100. The plurality of light source groups 200 are arranged side by side in the X direction. Each of the plurality of light source groups 200 has a first light source 20A and a second light source 20B. The first light source 20A and the second light source 20B are arranged side by side in the Y direction perpendicular to the X direction. The first wiring 12A is electrically connected to at least one of the first light source 20A and the second light source 20B. The first wiring 12A has a first extension part 121, a second extension part 122, and a third extension part 123. The first extension part 121 is located on the -X side with respect to the first light source 20A. The first extension part 121 extends in a first direction parallel to the Y direction. The second extension part 122 is located between the first light source 20A and the second light source 20B in the Y direction. The second extension part 122 extends from the first connection part 121A of the first extension part 121 in a second direction different from the first direction. The third extension part 123 is located on the +X side with respect to the second light source 20B. The third extension part 123 extends from the second connection part 122A of the second extension part 122 in the first direction.

[0012] Since the first wiring 12A with a small coefficient of linear expansion is positioned across the first light source 20A and the second light source 20B in the X direction, it is possible to reduce the expansion of the support 100 in the X direction due to the heat generated from the plurality of light source groups 200. By doing so, it is possible to reduce the widening of the intervals in the X direction of the plurality of light source groups 200. As a result, it becomes easier to reduce the unevenness in the luminance of the planar light source due to the change in the positions of the plurality of light source groups 200.

[0013] As shown in FIG. 1, the planar light source 300 of the present embodiment has a length in the X direction that is longer than the length in the Y direction. Hereinafter, each element constituting the planar light source 300 will be described in detail.

[0014] (Light source group 200) As shown in FIG. 2, the planar light source 300 has a plurality of light source groups 200 arranged side by side in the X direction. Each of the plurality of light source groups 200 has a first light source 20A and a second light source 20B. Each of the plurality of light source groups 200 may further have a third light source 20C and a fourth light source 20D. The first light source 20A and the second light source 20B are arranged side by side in the Y direction. In the present embodiment, the first light source 20A, the second light source 20B, the third light source 20C, and the fourth light source 20D are arranged side by side in the Y direction in this order. The first light source 20A, the second light source 20B, the third light source 20C, and / or the fourth light source 20D may be referred to as the light source unit 20.

[0015] As shown in Figure 3A, the light source unit 20 includes a light-emitting element 21. The light-emitting element 21 includes a semiconductor laminate. The semiconductor laminate includes, for example, a substrate such as sapphire or gallium nitride, an n-type semiconductor layer disposed on the substrate, a p-type semiconductor layer, and a light-emitting layer sandwiched between the n-type and p-type semiconductor layers. The light-emitting element 21 also includes an n-side electrode electrically connected to the n-type semiconductor layer and a p-side electrode electrically connected to the p-type semiconductor layer. The n-side electrode and the p-side electrode constitute a part of the lower surface of the light-emitting element 21. Furthermore, the light source unit 20 includes a pair of positive and negative electrodes 22. The pair of positive and negative electrodes 22 constitute a part of the lower surface of the light source unit 20. One of the pair of electrodes 22 is electrically connected to the p-side electrode, and the other is electrically connected to the n-side electrode. Note that the light source unit 20 does not necessarily include electrodes 22. If the light source unit 20 does not include a pair of positive and negative electrodes 22, the n-side electrode and p-side electrode of the light-emitting element 21 constitute a part of the lower surface of the light source unit 20. Furthermore, the light source unit 20 does not necessarily have to be equipped with a substrate such as sapphire or gallium nitride. This makes it easier to miniaturize the light source unit 20 in the vertical direction.

[0016] The structure of the light-emitting layer may be a double heterostructure, a single quantum well structure (SQW) with a single active layer, or a multiple quantum well structure (MQW) with a group of active layers. The light-emitting layer is capable of emitting visible light or ultraviolet light. The light-emitting layer is capable of emitting visible light from blue to red. An example of a semiconductor laminate containing such a light-emitting layer is In x Al y Ga 1-x-yN(0≦x, 0≦y, x+y≦1) may be included. The semiconductor stack may include at least one light-emitting layer capable of the light emission described above. For example, the semiconductor stack may have a structure that includes one or more light-emitting layers between an n-type semiconductor layer and a p-type semiconductor layer, or it may have a structure in which a structure containing an n-type semiconductor layer, a light-emitting layer, and a p-type semiconductor layer in sequence is repeated multiple times. When the semiconductor stack includes multiple light-emitting layers, it may include light-emitting layers with different emission peak wavelengths, or it may include light-emitting layers with the same emission peak wavelength. Note that the emission peak wavelengths may have variations of, for example, a few nanometers. Such combinations of light-emitting layers can be selected as appropriate. For example, when the semiconductor stack includes two light-emitting layers, the light-emitting layers can be selected in combinations such as 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. Furthermore, the light-emitting layer may include multiple active layers with different emission peak wavelengths, or it may include multiple active layers with the same emission peak wavelength.

[0017] The light source unit 20 shown in Figure 3A includes one light-emitting element 21. Each of the light source units 20 of the first light source 20A, second light source 20B, third light source 20C, and fourth light source 20D may include multiple light-emitting elements 21. The emission peak wavelengths of the multiple light-emitting elements included in each light source unit 20 may be the same or different. For example, if each light source unit 20 includes two light-emitting elements, the emission peak wavelengths of the light-emitting elements can be selected from combinations such as blue light and green light, blue light and red light, ultraviolet light and blue light, ultraviolet light and green light, ultraviolet light and red light, or green light and red light. For example, if each light source unit 20 includes three light-emitting elements, the emission peak wavelengths of the light-emitting elements can be selected from combinations such as blue light and green light and red light, ultraviolet light and green light and red light, ultraviolet light and blue light and green light, ultraviolet light and blue light and red light, or ultraviolet light and green light and red light.

[0018] As shown in FIG. 3A, the light source unit 20 can further include a translucent member 23 (hereinafter referred to as the light source translucent member). The light source translucent member 23 covers the upper surface and the side surface of the light emitting element 21. The light emitting element 21 can be protected by the light source translucent member 23. The light source translucent member 23 may be arranged so as to expose at least a part of the upper surface of the light emitting element 21. By doing so, it becomes easier to miniaturize the light source unit 20 in the vertical direction.

[0019] For example, the light source translucent member 23 has translucency with respect to the light emitted by the light emitting element 21. The light source translucent member 23 may include a translucent resin and may further include a phosphor. As the translucent resin, for example, a silicone resin or an epoxy resin can be used. As the phosphor, yttrium aluminum garnet-based phosphors (for example, (Y,Gd)3(Al,Ga)5O 12 :Ce), lutetium aluminum garnet-based phosphors (for example, Lu3(Al,Ga)5O 12 :Ce), terbium aluminum garnet-based phosphors (for example, Tb3(Al,Ga)5O 12 :Ce), CCA-based phosphors (for example, Ca 10 (PO4)6Cl2:Eu), SAE-based phosphors (for example, Sr4Al 14 O 25 :Eu), chlorosilicate-based phosphors (for example, Ca8MgSi4O 16 Cl2:Eu), silicate-based phosphors (for example, (Ba,Sr,Ca,Mg)2SiO4:Eu), β-sialon-based phosphors (for example, (Si,Al)3(O,N)4:Eu) or α-sialon-based phosphors (for example, Ca(Si,Al) 12 (O,N) 16 )]]:Eu) and other oxynitride-based phosphors, LSN-based phosphors (for example, (La,Y)3Si6N 11:Ce), BSESN-based phosphors (e.g., (Ba,Sr)2Si5N8:Eu), SLA-based phosphors (e.g., SrLiAl3N4:Eu), CASN-based phosphors (e.g., CaAlSiN3:Eu), or SCASN-based phosphors (e.g., (Sr,Ca)AlSiN3:Eu), etc., nitride-based phosphors, KSF-based phosphors (e.g., K2SiF6:Mn), KSAF-based phosphors (e.g., K2(Si 1-x Al x )F 6-x :Mn where x satisfies 0 < x < 1), or fluoride-based phosphors such as MGF-based phosphors (e.g., 3.5MgO·0.5MgF2·GeO2:Mn), quantum dots having a perovskite structure (e.g., (Cs,FA,MA)(Pb,Sn)(F,Cl,Br,I)3 where FA and MA represent formamidinium and methylammonium, respectively), II-VI group quantum dots (e.g., CdSe), III-V group quantum dots (e.g., InP), or quantum dots having a chalcopyrite structure (e.g., (Ag,Cu)(In,Ga)(S,Se)2), etc. can be used. As the phosphor added to the light source light transmissive member 23, one type of phosphor may be used, or a plurality of types of phosphors may be used.

[0020] Furthermore, the wavelength conversion sheet containing the aforementioned phosphor may be placed above the planar light source 300. The wavelength conversion sheet can absorb a portion of the blue light from the light source unit 20, emitting yellow light, green light, and / or red light, and thus becoming a planar light source that emits white light. For example, white light can be obtained by combining a light source unit 20 capable of emitting blue light with a wavelength conversion sheet containing a phosphor capable of emitting yellow light. Alternatively, a light source unit 20 capable of emitting blue light may be combined with a wavelength conversion sheet containing a red phosphor and a green phosphor. Furthermore, a light source unit 20 capable of emitting blue light may be combined with multiple wavelength conversion sheets. As for the multiple wavelength conversion sheets, for example, a wavelength conversion sheet containing a phosphor capable of emitting red light and a wavelength conversion sheet containing a phosphor capable of emitting green light can be selected. Alternatively, a light source unit 20 having a light-emitting element 21 capable of emitting blue light and a light-transmitting member 23 containing a phosphor capable of emitting red light may be combined with a wavelength conversion sheet containing a phosphor capable of emitting green light.

[0021] For the phosphor capable of emitting yellow light used in the wavelength conversion sheet, it is preferable to use, for example, the yttrium-aluminum-garnet phosphor described above. For the phosphor capable of emitting green light used in the wavelength conversion sheet, it is preferable to use, for example, quantum dots having a perovskite structure, III-V quantum dots, or quantum dots having a chalcopyrite structure, which have a narrow full width at half maximum of the emission peak wavelength, as described above. For the phosphor capable of emitting red light used in the wavelength conversion sheet, it is preferable to use, similar to the phosphor capable of emitting green light, quantum dots having a narrow full width at half maximum of the emission peak wavelength, such as, for example, the KSF phosphor, KSAF phosphor, III-V quantum dots, or quantum dots having a chalcopyrite structure, as described above.

[0022] The light source unit 20 may further include a covering member 24. The covering member 24 is positioned on the lower surface of the light-emitting element 21. The covering member 24 is positioned such that the lower surface of the electrode 22 of the light source unit 20 is exposed from the covering member 24. The covering member 24 is also positioned on the lower surface of the light-transmitting member 23 that covers the side surface of the light-emitting element 21.

[0023] The coating member 24 has reflectivity to light emitted by the light-emitting element 21. The coating member 24 can be made of, for example, a resin material containing a gas such as nitrogen or oxygen, or a resin material containing light-scattering particles. As the resin material of the coating member 24, for example, thermoplastic resins such as acrylic resin, polycarbonate resin, cyclic polyolefin resin, polyethylene terephthalate resin, or polyester resin, or thermosetting resins such as epoxy resin or silicone resin can be used. As the light-scattering particles of the coating member 24, for example, particles such as titania, silica, alumina, zinc oxide, magnesium oxide, zirconia, yttria, calcium fluoride, magnesium fluoride, niobium pentoxide, barium titanate, tantalum pentoxide, barium sulfate, or glass can be used. The coating member 24 may contain both gas and light-scattering particles.

[0024] As shown in Figure 3A, the light source unit 20 may include a light adjustment member 25 (hereinafter referred to as the light source light adjustment member). The light source light adjustment member 25 constitutes at least a part of the upper surface of the light source unit 20. The light source light adjustment member 25 is positioned above the light-emitting element 21. In a top view, the light source light adjustment member 25 and the light-emitting element 21 overlap, and in the overlapping portion, the light source light adjustment member 25 is positioned above the light-emitting element 21. The light source light adjustment member 25 is positioned above the light-transmitting member 23 and adjusts the amount and direction of light emitted from the upper surface of the light-transmitting member 23. The light source light adjustment member 25 has reflectivity and transmittance to the light emitted by the light-emitting element 21. A portion of the light emitted from the upper surface of the light-transmitting member 23 is reflected by the light source light adjustment member 25, and another portion is transmitted through the light source light adjustment member 25. The transmittance of the light source light adjustment member 25 with respect to the peak wavelength of the light-emitting element 21 is preferably 1% to 50%, and more preferably 3% to 30%. By including the light source light adjustment member 25 in the light source unit 20, it is possible to reduce the area directly above the light source unit 20 from becoming too bright. This reduces the brightness unevenness of the planar light source 300.

[0025] The light source light adjustment member 25 can be made of, for example, a resin member containing light scattering particles. The resin member of the light source light adjustment member 25 can be made of the same material as the resin member of the coating member 24. The light scattering particles of the light source light adjustment member 25 can be made of the same material as the light scattering particles of the coating member 24. Furthermore, the light source light adjustment member 25 may be made of, for example, a metal member such as aluminum or silver, or a dielectric multilayer film.

[0026] As shown in Figure 3B, the light source unit 20 does not have to include the light source light adjustment member 25. This makes it easier to miniaturize the light source unit 20 in the vertical direction compared to when the light source unit 20 includes the light source light adjustment member 25 which is positioned above the light-emitting element 21. As for other forms of the light source unit 20, the light source unit 20 does not have to include the covering member 24. For example, the lower surface of the light source unit may be composed of the lower surface of the light-emitting element, the lower surfaces of the pair of electrodes 22, and the lower surface of the light-transmitting member. As for other forms of the light source unit 20, the light source unit 20 may consist only of the light-emitting element 21. As for other forms of the light source unit 20, the light source unit 20 may not include the covering member 24 and the light-transmitting member 23, and the light source light adjustment member 25 may be positioned on the upper surface of the light-emitting element 21. As for other forms of the light source unit 20, the light source unit 20 may not include the light-transmitting member 23, the light source light adjustment member 25 may be positioned on the upper surface of the light-emitting element 21, and the covering member 24 may be positioned on the lower surface of the light-emitting element 21.

[0027] The shape of the light source unit 20 in a top view is not particularly limited. The shape of the light source unit 20 in a top view can be, for example, a circle, a triangle, a square, a hexagon, or an octagon. If the shape of the light source unit 20 in a top view is a square, the pair of outer edges of the light source unit 20 may be parallel to the X direction or inclined with respect to the X direction. In this embodiment, the pair of outer edges of the light source unit 20 are inclined at 45° with respect to the X direction.

[0028] (Support 100) The support 100 is a member on which a plurality of light source groups 200 are mounted. As shown in Figure 4, the support 100 has a base material 11 and a first wiring 12A. The coefficient of thermal expansion of the first wiring 12A is smaller than the coefficient of thermal expansion of the base material 11. The base material 11 includes a first surface 111A. In this embodiment, the first surface 111A is the bottom surface of the base material 11. The first surface 111A may also be the top surface of the base material 11. The first wiring 12A is arranged on the first surface 111A of the base material 11. The first wiring 12A is electrically connected to at least one of the first light source 20A and the second light source 20B.

[0029] The substrate 11 may be a rigid substrate or a flexible substrate. For the purpose of thinning the planar light source, the substrate 11 is preferably a flexible substrate. The substrate 11 may be composed of a single layer in the vertical direction or a laminate of multiple layers. For example, the substrate 11 may be composed of a single-layer flexible substrate or a laminate of multiple rigid substrates. As the material for the substrate 11, for example, a resin such as polyimide can be used. As the material for the first wiring 12A, for example, a metal film such as a copper film can be used. As the material for the first wiring 12A, a conductive paste containing resin and metal particles contained in the resin may be used. As the resin for the first wiring 12A, for example, epoxy resin or phenolic resin can be used. As the metal particles for the first wiring 12A, for example, copper or silver particles can be used.

[0030] As shown in Figures 5 and 6, the first wiring 12A has a first extension 121, a second extension 122, and a third extension 123. The first extension 121 is located on the -X side with respect to the first light source 20A. The first extension 121 extends in a first direction parallel to the Y direction. The second extension 122 is located between the first light source 20A and the second light source 20B in the Y direction. In this specification, "located between" means that at least a part of the member is located between. For example, "the second extension 122 is located between the first light source 20A and the second light source 20B in the Y direction" means that at least a part of the second extension 122 is located between the first light source 20A and the second light source 20B in the Y direction. The second extension portion 122 extends from the first connection portion 121A of the first extension portion 121 in a second direction different from the first direction (Y direction). The third extension portion 123 is located on the +X side with respect to the second light source 20B. The third extension portion 123 extends from the second connection portion 122A of the second extension portion 122 in the first direction (Y direction). In the X direction, at least a portion of the first extension portion 121 overlaps with the first light source 20A. In the X direction, at least a portion of the third extension portion 123 overlaps with the second light source 20B. In this embodiment, the second extension portion 122 is located on the +Y side with respect to the first light source 20A and on the -Y side with respect to the second light source 20B. The first wiring 12A only needs to have a first extension 121 that is located on the -X side with respect to the first light source 20A of at least one of the multiple light source groups 200, and extends in a first direction parallel to the Y direction.

[0031] As shown in Figure 5, being located on the -X side relative to the first light source 20A means being located to the right of the first light source 20A, and being located on the +X side relative to the second light source 20B means being located to the left of the second light source 20B. Note that in Figure 5, the X direction is from right to left, but the X direction may also be from left to right. If the X direction is from left to right, being located on the -X side relative to the first light source 20A means being located to the left of the first light source 20A, and being located on the +X side relative to the second light source 20B means being located to the right of the second light source 20B.

[0032] By positioning the first wiring 12A, which has a smaller coefficient of thermal expansion than the substrate 11, across the first light source 20A and the second light source 20B in the X direction, the expansion of the support 100 in the X direction due to heat generated from the multiple light source groups 200 can be reduced. In this way, the widening of the spacing between the multiple light source groups 200 arranged in the X direction can be reduced. This makes it easier to reduce brightness unevenness of the planar light source caused by changes in the position of the multiple light source groups 200.

[0033] As shown in Figures 7A and 7B, the first connection portion 121A of the first extension portion 121 (shown by the shaded hatching) is a part of the first extension portion 121 that connects to the second extension portion 122. As shown in Figure 7A, the outer edge of the first connection portion 121A of the first extension portion 121 may be made of a curve, and as shown in Figure 7B, the outer edge of the first connection portion 121A of the first extension portion 121 may be made of a straight line. It is preferable that the outer edge of the first connection portion 121A of the first extension portion 121 has a curved portion. By doing so, the concentration of stress at one point on the outer edge of the first connection portion 121A of the first extension portion 121 can be reduced compared to when the outer edge of the first connection portion 121A of the first extension portion 121 is made of a straight line. This reduces the occurrence of cracks in the first wiring. Similarly, it is preferable that the outer edge of the second connection portion 122A has a curved portion.

[0034] The second direction in which the second extension portion 122 extends may be parallel to the X direction, or it may be inclined with respect to the X direction as shown in Figure 5. Preferably, the second direction is inclined with respect to the X direction toward the +Y side. This makes it easier to shorten the length of the first wiring 12A compared to when the second direction is parallel to the X direction. This makes it easier to reduce the electrical resistance of the first wiring 12A, and thus easier to reduce the power consumption of the planar light source 300.

[0035] As shown in Figure 5, the first wiring 12A may further have a fourth extension 124 and a fifth extension 125. The fourth extension 124 extends from the third connection 123A of the third extension 123 in a third direction different from the first direction (Y direction). The fifth extension 125 is located on the -X side with respect to the third light source 20C and extends from the fourth connection 124A of the fourth extension 124 in the first direction (Y direction). In the X direction, at least a portion of the fifth extension 125 overlaps with the third light source 20C. In the Y direction, the fourth extension 124 is located between the second light source 20B and the third light source 20C. By having the fourth extension 124 and the fifth extension 125 in the first wiring 12A, the expansion of the support 100 in the X direction can be reduced.

[0036] As shown in Figure 5, the first wiring 12A may further include a sixth extension 126. The sixth extension 126 extends from the fifth connection portion 125A of the first extension 121 in a fourth direction different from the first direction (Y direction). In the Y direction, the first light source 20A is located between the second extension 122 and the sixth extension 126. The presence of the sixth extension 126 in the first wiring 12A reduces the expansion of the support 100 in the X direction. It is preferable that the sixth extension 126 has a portion located on the +X side and a portion located on the -X side of the outer edge of the first light source 20A. This makes it easier to reduce the expansion of the support 100 in the X direction. In this embodiment, one end of the sixth extension 126 is not connected to a part of the first wiring 12A that extends in a direction different from the fourth direction. In this embodiment, the other end of the sixth extension 126 is connected to the fifth connecting portion 125A of the first extension 121. In this embodiment, the fourth direction in which the sixth extension 126 extends is parallel to the second direction in which the second extension 122 extends.

[0037] As shown in Figures 6 and 7C, the first wiring 12A may further include a seventh extension 127 and an eighth extension 128. As shown in Figure 7C, the seventh extension 127 extends in the first direction (Y direction) from the sixth connection 126A (shown by shaded hatching) of the sixth extension 126. The eighth extension 128 extends in the X direction from the seventh connection 127A (shown by shaded hatching) of the seventh extension 127. By having the seventh extension 127 and the eighth extension 128 in the first wiring 12A, the expansion of the support 100 in the X direction and / or Y direction can be reduced. Preferably, the eighth extension 128 has a portion extending to the +X side and a portion extending to the -X side from the seventh connection of the seventh extension 127. This makes it easier to reduce the expansion of the support 100 in the X direction. Preferably, the eighth extension portion 128 has a portion located on the +X side and a portion located on the -X side of the outer edge of the first light source 20A. This makes it easier to reduce the expansion of the support 100 in the X direction.

[0038] As shown in Figures 6 and 7C, the first wiring 12A may further include a ninth extension 129 and a tenth extension 130. As shown in Figure 7C, the ninth extension 129 extends in the first direction (Y direction) from the eighth connection 128A (shown by shaded hatching) of the eighth extension 128. The tenth extension 130 extends in the X direction from the ninth connection 129A (shown by shaded hatching) of the ninth extension 129. As shown in Figure 6, the tenth extension 130 extends in the X direction away from the first light source 20A. By having the ninth extension 129 and the tenth extension 130 in the first wiring 12A, expansion of the support 100 in the X direction and / or Y direction can be reduced. Preferably, the length of the ninth connection 129A in the X direction increases as it approaches the first light source. In this way, expansion of the support 100 in the X direction can be reduced. The ninth extended portion 129 and / or the tenth extended portion 130 are in contact with the conductive member 50, which will be described later. In this embodiment, the ninth connecting portion 129A is in contact with the conductive member.

[0039] As shown in Figures 4 and 5, it is preferable that the support 100 further has a second wiring 12B having a lower coefficient of thermal expansion than the base material 11. The second wiring 12B is located on the second surface 111B, which is opposite to the first surface 111A. The second wiring 12B extends in the X direction. In the Y direction, the second wiring 12B is located between the first light source 20A and the second light source 20B. By having the second wiring 12B in the support 100, the expansion of the support 100 in the X direction can be reduced. The material of the second wiring 12B can be the same as the material of the first wiring 12A. The materials of the first wiring 12A and the second wiring 12B may be the same or different. For example, a metal film such as a copper film may be used as the material of the first wiring 12A, and a conductive paste may be used as the material of the second wiring 12B. In this embodiment, the first wiring 12A and the second wiring 12B are electrically connected via a via 12D.

[0040] As shown in Figure 5, in a bottom view, it is preferable that the second wiring 12B is arranged across multiple light source groups 200. This makes it easier to reduce the expansion of the support 100 in the X direction.

[0041] Preferably, the length of the second wiring 12B in the Y direction is longer than the length of the first extension 111 in the X direction. This makes it easier to increase the volume of the second wiring 12B. This makes it easier to reduce the expansion of the support 100 in the X direction by the second wiring 12B. In this specification, the length of each member refers to the value at which the length of each member is at its maximum. For example, the length of the second wiring 12B in the Y direction refers to the value at which the length of the second wiring 12B in the Y direction is at its maximum.

[0042] As shown in Figures 5 and 6, it is preferable that at least a portion of the second wiring 12B overlaps with the first extended portion 111 in a bottom view. This makes it easier to reduce the expansion of the support 100 in the X direction near the first extended portion 111.

[0043] As shown in Figure 4, it is preferable that the thickness of the second wiring 12B is greater than the thickness of the first wiring 12A. This makes it easier to reduce the expansion of the support 100 in the X direction by the second wiring 12B. In this specification, the thickness of each member is defined as the value at which the length of each member in the vertical direction is maximized.

[0044] As shown in Figures 4, 5, and 6, it is preferable that the support 100 further has a third wiring 12C having a lower coefficient of thermal expansion than the base material 11. The third wiring 12C is positioned on the second surface 111B. The third wiring 12C extends in the X direction. In the Y direction, the first light source 20A is positioned between the second wiring 12B and the third wiring 12C. The third wiring 12C is positioned on the -Y side with respect to the first light source 20A. By having the third wiring 12C in the support 100, it becomes easier to reduce the expansion of the support 100 in the X direction. The material of the third wiring 12C can be the same as the material of the first wiring 12A. The materials of the first wiring 12A and the third wiring 12C may be the same or different. For example, a metal film such as a copper film may be used as the material of the first wiring 12A, and a conductive paste may be used as the material of the second wiring 12B and the third wiring 12C.

[0045] As shown in Figure 5, in a bottom view, it is preferable that the third wiring 12C is arranged across multiple light source groups 200. This makes it easier to reduce the expansion of the support 100 in the X direction.

[0046] Preferably, the length of the third wiring 12C in the Y direction is longer than the length of the first extension 111 in the X direction. This makes it easier to increase the volume of the third wiring 12C. This makes it easier to reduce the expansion of the support 100 in the X direction by the third wiring 12C.

[0047] As shown in Figures 5 and 6, it is preferable that at least a portion of the third wiring 12C overlaps with the first extended portion 111 in a bottom view. This makes it easier to reduce the expansion of the support 100 in the X direction near the first extended portion 111. It is also preferable that at least a portion of the third wiring 12C overlaps with the sixth extended portion 126 in a bottom view. This makes it easier to reduce the expansion of the support 100 in the X direction near the sixth extended portion 126.

[0048] As shown in Figure 4, it is preferable that the thickness of the third wiring 12C is greater than the thickness of the first wiring 12A. This makes it easier to reduce the expansion of the support 100 in the X direction by the third wiring 12C.

[0049] As shown in Figure 4, the support 100 may further include a first adhesive layer 31 disposed on the substrate 11, a reflective member 40 disposed on the first adhesive layer 31, and a second adhesive layer 32 disposed on the reflective member 40.

[0050] The first adhesive layer 31 is placed between the substrate 11 and the reflective member 40, and adheres the substrate 11 and the reflective member 40. The first adhesive layer 31 can be made of, for example, a resin member containing light-scattering particles. As the resin member of the first adhesive layer 31, for example, a material similar to that of the resin member of the coating member 24 can be used. As the light-scattering particles of the first adhesive layer 31, for example, a material similar to that of the light-scattering particles of the coating member 24 can be used. A sheet-like optical transparent adhesive may be used as the first adhesive layer 31.

[0051] Preferably, the refractive index of the resin member of the first adhesive layer 31 is lower than that of the resin member of the reflective member 40. This makes it easier for some of the light traveling from the reflective member 40 to the first adhesive layer 31 to undergo total internal reflection at the interface between the reflective member 40 and the first adhesive layer 31. This reduces the amount of light that passes downward through the planar light source 300, thereby improving the light extraction efficiency of the planar light source 300.

[0052] The reflective member 40 is reflective to the light emitted by the light source 20. It is positioned below the light source 20. The reflective member 40 can be composed of a resin member and a reflector contained within the resin member. For example, the same material as the resin member of the covering member 24 can be used as the resin member of the reflective member 40. The same material as the light scattering particles of the covering member 24 can be used as the reflector material of the reflective member 40. A gas such as nitrogen or oxygen may be used as the reflector of the reflective member 40. Furthermore, the reflective member 40 may contain both light scattering particles and a gas as the reflector.

[0053] Preferably, the refractive index of the reflector of the reflective member 40 is lower than the refractive index of the resin member of the reflective member 40. This makes it easier for some of the light from the light source 20 incident on the reflective member 40 to undergo total internal reflection at the interface between the resin member of the reflective member 40 and the reflector of the reflective member 40. As a result, the amount of light that escapes downward from the reflective member 40 is reduced, improving the light extraction efficiency of the planar light source 300.

[0054] The second adhesive layer 32 is positioned between the reflective member 40 and the light source unit 20, and adheres the reflective member 40 and the light source unit 20. The light source unit 20 is positioned on the second adhesive layer 32. The second adhesive layer 32 can be made of, for example, a resin member containing light-scattering particles. As the resin member of the second adhesive layer 32, for example, a material similar to the resin member of the covering member 24 can be used. As the light-scattering particles of the second adhesive layer 32, for example, a material similar to the light-scattering particles of the covering member 24 can be used. A sheet-like optical transparent adhesive may be used as the second adhesive layer 32.

[0055] The support 100 further includes a conductive member 50. For example, a conductive paste can be used as the material for the conductive member 50. As shown in Figure 4, the conductive member 50 is in contact with the electrode 22 of the light source unit 20.

[0056] The conductive member 50 has a connecting portion 51 and a wiring portion 52. The connecting portion 51 penetrates the second adhesive layer 32, the reflective member 40, the first adhesive layer 31, and the base material 11 in the vertical direction. The wiring portion 52 electrically connects the connecting portion 51 and the first wiring 12A. The connecting portion 51 and the wiring portion 52 can be integrally formed from the same material.

[0057] A pair of conductive members 50 are arranged apart from each other, corresponding to the positive and negative electrodes 22 of the light source unit 20. The connection portion 51 of one conductive member 50 is connected to the positive electrode 22 below the light source unit 20, and the connection portion 51 of the other conductive member 50 is connected to the negative electrode 22 below the light source unit 20.

[0058] As shown in Figures 5 and 6, it is preferable that the length of the conductive member 50 in the X direction is longer than the length of the first light source 20A in the X direction. If the coefficient of thermal expansion of the conductive member 50 is smaller than that of the substrate 11, the expansion of the support 100 in the X direction can be reduced by increasing the length of the conductive member 50 in the X direction.

[0059] As shown in Figures 5 and 6, it is preferable that the conductive member 50 has a portion located on the +X side and a portion located on the -X side of the outer edge of the first light source 20A. This makes it easier to reduce the expansion of the support 100 in the X direction near the first light source 20A. This makes it easier to reduce brightness unevenness of the planar light source caused by changes in the position of the first light source 20A.

[0060] As shown in Figure 6, in a view from below, it is preferable that a portion of the outer edge of one conductive member 50 and a portion of the outer edge of the other conductive member 50 are parallel. This reduces the likelihood of short circuits between the conductive members 50.

[0061] It is preferable that the conductive member 50 is connected to the first wiring 12A at multiple points. This makes it easier to reduce the interruption of a part of the electrical circuit. As shown in Figure 6, in this embodiment, the conductive member 50 and the first wiring 12A are connected at two points, the first part 52A and the second part 52B. However, the conductive member 50 may be connected to the first wiring 12A at only one point.

[0062] Preferably, the support 100 further has an insulating layer 60 that protects the lower surface of the base material 11. In this embodiment, the insulating layer 60 is placed on the lower surface of the base material 11 and covers the first wiring 12A. For example, epoxy resin, urethane resin, or acrylic resin can be used as the material for the insulating layer 60. Figures 5 and 6 are schematic lower views of a part of a planar light source with the insulating layer 60 omitted.

[0063] (Light guide member 70) As shown in Figure 4, the planar light source 300 may have a light guide member 70 having a hole 70H in which the light source unit 20 is arranged. The light guide member 70 is a member that is transparent to the light emitted by the light source unit 20. The transmittance of the light guide member 70 with respect to the peak wavelength of the light source unit 20 is preferably 60% or more, and more preferably 80% or more. In this embodiment, the planar light source 300 has a first light guide member 70A in which the first light source 20A is arranged, a second light guide member 70B in which the second light source 20B is arranged, a third light guide member 70C in which the third light source 20C is arranged, and a fourth light guide member 70D in which the fourth light source 20D is arranged. The first light guide member 70A, the second light guide member 70B, the third light guide member 70C and / or the fourth light guide member 70D may be referred to as the light guide member 70.

[0064] The light guide member 70 has a first light guide surface 701 which becomes the light-emitting surface of the planar light source 300, and a second light guide surface 702 located on the opposite side of the first light guide surface 701. The light guide member 70 continuously surrounds the light source unit 20 when viewed from above. In this embodiment, the light guide member 70 has a hole 70H that penetrates from the first light guide surface 701 to the second light guide surface 702. The light source unit 20 is positioned in the hole 70H of the light guide member 70. In this embodiment, the hole 70H is circular when viewed from above. The hole 70H may be elliptical, or polygonal in shape such as a triangle, square, hexagon, or octagon when viewed from above. The hole 70H may also be a recess that opens only on the side of the second light guide surface 702 of the light guide member 70.

[0065] In this embodiment, each of the multiple light guide members 70 is a different light-emitting region 300A. One light-emitting region 300A can be used as a driving unit for local dimming. The number of light-emitting regions 300A constituting the planar light source 300 is not particularly limited. For example, the planar light source 300 may have one light-emitting region 300A, or, as in this embodiment, may have multiple light-emitting regions 300A. Furthermore, by arranging multiple planar light sources 300, a planar light source device with a larger area can be created.

[0066] As shown in Figures 4 and 6, it is preferable that the first light guide member 70A and the second light guide member 70B are arranged with a gap 70G between them. This reduces the warping of the support 100 caused by the difference in thermal expansion coefficients between the light guide members 70 and the support 100. This reduces the occurrence of cracks in the conductive member 50. It is preferable that each of the multiple light guide members 70 is arranged with a gap between them.

[0067] As shown in Figure 6, in a view from below, it is preferable that at least a portion of the first connecting portion 121A and / or at least a portion of the second extending portion 122 overlap with the gap 70G between the first light guide member 70A and the second light guide member 70B. Since the second extending portion 122 extends in a second direction different from the Y direction, the length of the first connecting portion 121A and the second extending portion 122 in the X direction is easier to make longer than that of the first extending portion 121 which extends parallel to the Y direction. For this reason, by having at least a portion of the first connecting portion 121A and / or at least a portion of the second extending portion 122 overlap with the gap 70 between the first light guide member 70A and the second light guide member 70B, it is easier to reduce the expansion of the support 100 in the X direction near the gap 70G between the first light guide member 70A and the second light guide member 70B.

[0068] As shown in Figure 6, it is preferable that, in a bottom view, the second wiring 12B and the gap 70G between the first light guide member 70A and the second light guide member 70B are located at a distance from each other. If the base material 11 is flexible, the distance between the second wiring 12B and the gap 70G between the first light guide member 70A and the second light guide member 70B in a bottom view makes it easier to bend the support 100 along the X direction. However, in a bottom view, at least a portion of the second wiring 12B may overlap with the gap 70G between the first light guide member 70A and the second light guide member 70B. This makes it easier to reduce the expansion of the support 100 in the X direction near the gap 70G between the first light guide member 70A and the second light guide member 70B.

[0069] The light guide member 70 preferably has a recess 71 that opens into the first light guide surface 701 or the second light guide surface 702. This makes it easier to increase the surface area of ​​the light guide member 70. This makes it easier to increase the amount of light extracted from the surface of the light guide member 70 to the outside of the light guide member 70, thereby making it easier to improve the light extraction efficiency of the planar light source 300. The light guide member 70 may also have through holes that open into the first light guide surface 701 and the second light guide surface 702. This also makes it easier to increase the surface area of ​​the light guide member 70.

[0070] The shape of the recess 71 of the light guide member 70 is not particularly limited. As shown in Figure 2, the shape of the recess 71 of the light guide member 70 in this embodiment may include linear portions. In this specification, linear includes straight lines, curves, or bent lines. For example, the shape of the recess 71 of the light guide member 70 in a top view may include V-shaped or L-shaped portions extending in two directions. The shape of the recess 71 of the light guide member 70 in a top view may be circular, triangular, square, hexagonal, or octagonal. Furthermore, the shape and / or number of recesses 71 of the first light guide member 70A and the shape and / or number of recesses 71 of the second light guide member 70B may be the same or different.

[0071] The material used for the light guide member 70 can be the same material as the resin material used for the covering member 24. Alternatively, glass or the like may be used as the material for the light guide member 70. The light guide member 70 may also contain phosphors or light scattering particles.

[0072] The thickness of the light guide member 70 is preferably, for example, 150 μm or more and 800 μm or less. The light guide member 70 may be composed of a single layer in the vertical direction, or it may be composed of a laminate of multiple layers. If the light guide member 70 is composed of a laminate, a light-transmitting adhesive may be placed between each layer. Each layer of the laminate may use a different type of main material.

[0073] (Translucent member 80) As shown in Figure 4, the planar light source 300 may include a light-transmitting member 80. The light-transmitting member 80 is a member that is transparent to light emitted from the light source unit 20. The light-transmitting member 80 has a first light-transmitting portion 81 and a second light-transmitting portion 82. In this embodiment, the first light-transmitting portion 81 and the second light-transmitting portion 82 are separate components. The first light-transmitting portion 81 and the second light-transmitting portion 82 may be integrally formed from the same material. The transmittance of the first light-transmitting portion 81 and the second light-transmitting portion 82 with respect to the peak wavelength of the light source unit 20 is preferably 60% or more, and more preferably 80% or more.

[0074] As shown in Figure 4, it is preferable that the first light-transmitting portion 81 is in contact with the side surface of the light source portion 20. This makes it easier for light from the light source portion 20 to enter the first light-transmitting portion 81. It is also preferable that the first light-transmitting portion 81 is in contact with the light guide member 70. This makes it easier for light from the light source portion 20 to enter the light guide member 70.

[0075] It is preferable that the first light-transmitting portion 81 is arranged to expose at least a portion of the upper surface of the light source unit 20. This makes it easier to miniaturize the planar light source 300 in the vertical direction compared to when the first light-transmitting portion 81 covers the entire upper surface of the light source unit 20. The first light-transmitting portion 81 may be arranged to expose the entire upper surface of the light source unit 20. Alternatively, the first light-transmitting portion 81 may cover the entire upper surface of the light source unit 20. By having the first light-transmitting portion 81 cover the entire upper surface of the light source unit 20, it becomes easier to adjust the brightness in the region directly above the light source unit 20. For example, the brightness in the region directly above the light source unit 20 can be adjusted by changing the thickness of the first light-transmitting portion 81 in the portion that covers the upper surface of the light source unit 20. This makes it easier to adjust the brightness, thus making it easier to reduce brightness unevenness in the planar light source 300. When the first light-transmitting portion 81 covers the upper surface of the light source unit 20, the second light-transmitting portion 82 covers the upper surface of the light source unit 20 via the first light-transmitting portion 81.

[0076] The first light-transmitting portion 81 may be composed of a single layer or a laminate of multiple layers in the vertical direction. The first light-transmitting portion 81 may also contain phosphors or light-scattering particles. If the first light-transmitting portion 81 is a laminate, each layer may or may not contain phosphors and / or light-scattering particles. For example, the first light-transmitting portion 81 may consist of a layer containing phosphors and a layer not containing phosphors. As the material for the first light-transmitting portion 81, for example, a material similar to that of the resin member of the covering member 24 can be used.

[0077] The second light-transmitting section 82 is located above the light source section 20. The second light-transmitting section 82 is located above the first light-transmitting section 81. It is preferable that the second light-transmitting section 82 is in contact with the upper surface of the light source section 20 and / or the upper surface of the first light-transmitting section 81. This makes it easier to miniaturize the planar light source 300 in the vertical direction.

[0078] For example, the material used for the second light-transmitting portion 82 can be the same material as the resin material used for the covering member 24. Alternatively, a sheet-like optical transparent adhesive (OCA) may be used for the second light-transmitting portion 82. The second light-transmitting portion 82 may also contain phosphors or light-scattering particles.

[0079] (Light adjusting member 90) As shown in Figure 4, the planar light source 300 may be equipped with a light adjustment member 90. The light adjustment member 90 has reflectivity and light transmission properties to the light emitted from the light source unit 20. A portion of the light emitted from the light source unit 20 is reflected by the light adjustment member 90, and another portion is transmitted through the light adjustment member 90. The transmittance of the light adjustment member 90 with respect to the peak wavelength of the light source unit 20 is lower than the transmittance of the light guide member 70 with respect to the peak wavelength of the light source unit 20. For example, the transmittance of the light adjustment member 90 with respect to the peak wavelength of the light source unit 20 is preferably 1% or more and 50% or less, and more preferably 3% or more and 30% or less. The light adjustment member 90 may be composed of a single layer or a laminate of multiple layers.

[0080] The light adjustment member 90 is positioned above the light source unit 20. In a top view, the light adjustment member 90 and the light source unit 20 overlap, and the light adjustment member 90 is positioned above the light source unit 20 at the overlapping portion. By positioning the light adjustment member 90 above the light source unit 20, it is possible to reduce the excessive brightness in the area directly above the light source unit 20.

[0081] As shown in Figure 2, in a top view, it is preferable that at least a portion of the outer edge of the light adjusting member 90 is located outside the outer edge of the hole 70H of the light guide member 70. This reduces excessive brightness near the outer edge of the hole 70H. In a top view, the entire outer edge of the light adjusting member 90 may be located outside the outer edge of the hole 70H. This further reduces excessive brightness near the outer edge of the hole 70H.

[0082] The light adjustment member 90 may have a light adjustment through-hole 90A. Having a light adjustment through-hole 90A makes it easier to adjust the brightness in the area directly above the light adjustment member 90. For example, by changing the size or position of the light adjustment through-hole 90A, the light from the light source 20 that is blocked by the light adjustment member 90 can be adjusted. This makes it easier to adjust the brightness in the area directly above the light adjustment member 90, thus reducing brightness unevenness in the planar light source 300.

[0083] The light adjustment through-hole 90A of the light adjustment member 90 is preferably located away from the light source unit 20 when viewed from above. This reduces the likelihood of the area directly above the light source unit 20 becoming too bright.

[0084] The shape of the light-adjusting through-hole 90A in a top view is not particularly limited. As shown in Figure 2, the shape of the light-adjusting through-hole 90A in a top view is circular. The shape of the light-adjusting through-hole 90A in a top view may be elliptical, or a polygon such as a triangle, square, hexagon, or octagon. The shape of the light-adjusting through-hole 90A in a top view may include linear portions.

[0085] In a top view, it is preferable that multiple light adjustment through-holes 90A surround the light source unit 20. This makes it easier to adjust the brightness of the planar light source 300 in the X and / or Y directions.

[0086] As shown in Figure 2, in a top view, it is preferable that the light adjustment member 90 has a plurality of recesses 90B (hereinafter referred to as light adjustment recesses) that are recessed in the lateral direction. The light adjustment recesses 90B are provided on the outer edge of the light adjustment member 90. The presence of light adjustment recesses 90B in the light adjustment member 90 makes it easier to adjust the brightness around the light adjustment member 90. For example, by changing the size and position of the light adjustment recesses 90B, the light from the light source 20 that is blocked by the light adjustment member 90 can be adjusted. This makes it easier to adjust the brightness around the light adjustment member 90, thus making it easier to reduce brightness unevenness of the planar light source 300. The size of the light adjustment recesses 90B is not particularly limited. The maximum length of the light adjustment recesses 90B in the X direction may be shorter than the maximum length of the light adjustment through-holes 90A in the X direction. The maximum length of the light adjustment recesses 90B in the Y direction may be shorter than the maximum length of the light adjustment through-holes 90A in the Y direction.

[0087] The light-adjusting member 90 can be composed of a resin member and a reflector contained within the resin member. For example, the same material as the resin member of the coating member 24 can be used as the resin member of the light-adjusting member 90. The same material as the light-scattering particles of the coating member 24 can be used as the reflector material of the light-adjusting member 90. A gas such as nitrogen or oxygen may be used as the reflector of the light-adjusting member 90. Furthermore, the light-adjusting member 90 may contain both light-scattering particles and a gas as the reflector.

[0088] This specification includes the following embodiments. Item 1. A support comprising a base material and a first wiring having a smaller coefficient of thermal expansion than the base material and arranged on the first surface of the base material, The system comprises a plurality of light source groups arranged on the support and aligned in the X direction, Each of the multiple light source groups has a first light source and a second light source arranged side by side in the Y direction perpendicular to the X direction, The first wiring is electrically connected to at least one of the first light source and the second light source, and has a first extension portion located on the -X side with respect to the first light source and extending in a first direction parallel to the Y direction, a second extension portion located between the first light source and the second light source in the Y direction and extending from a first connection portion of the first extension portion in a second direction different from the first direction, and a third extension portion located on the +X side with respect to the second light source and extending from a second connection portion of the second extension portion in the first direction. Item 2. The light source group has a third light source arranged in the order of the first light source, the second light source, and the third light source in the Y direction, The planar light source according to claim 1, wherein the first wiring comprises a fourth extension portion extending in a third direction different from the first direction from a third connection portion of the third extension portion, and a fifth extension portion located on the -X side with respect to the third light source and extending in the first direction from a fourth connection portion of the fourth extension portion. Item 3. The support has a second wiring positioned on the second surface opposite to the first surface and extending in the X direction, The second wiring is a planar light source according to item 1 or item 2, located between the first light source and the second light source in the Y direction. Item 4. The planar light source according to Item 3, wherein the length of the second wiring in the Y direction is longer than the length of the first extension in the X direction. Item 5. The planar light source according to item 3 or 4, wherein, in a view from below, at least a portion of the second wiring overlaps with the first extension. Item 6. A planar light source according to any one of items 3 to 5, wherein the thickness of the second wiring is greater than the thickness of the first wiring. Item 7. A first light guide member on which the first light source is arranged, The system further comprises a second light guide member on which the second light source is arranged, The first light guide member and the second light guide member are arranged with a gap between them. A planar light source according to any one of claims 1 to 6, wherein, in a view from below, at least a portion of the first connecting portion and / or at least a portion of the second extension portion overlaps with the gap. Item 8. Further comprising a conductive member in contact with the first light source, The planar light source according to any one of items 1 to 7, wherein the length of the conductive member in the X direction is longer than the length of the first light source.

[0089] The embodiments of the present invention have been described above with reference to specific examples. However, the present invention is not limited to these specific examples. All forms that a person skilled in the art can implement by appropriately modifying the design based on the above-described embodiments of the present invention also fall within the scope of the present invention, insofar as they encompass the gist of the present invention. Furthermore, within the scope of the idea of ​​the present invention, a person skilled in the art can conceive of various modifications and alterations, and these modifications and alterations also fall within the scope of the present invention. [Explanation of Symbols]

[0090] 11 Base material 12A First Wiring 12B Second Wiring 20 Light source section 31 1st adhesive layer 32 Second adhesive layer 40 Reflective material 50 Conductive members 60 Insulating layer 70 Light guide member 80 Translucent material 90 Light adjustment member 100 support 200 light source group 300 Planar light source

Claims

1. A support comprising a base material and a first wiring having a smaller coefficient of thermal expansion than the base material and arranged on the first surface of the base material, The system comprises a plurality of light source groups arranged on the support and aligned in the X direction, Each of the multiple light source groups has a first light source and a second light source arranged side by side in the Y direction perpendicular to the X direction, The first wiring is electrically connected to at least one of the first light source and the second light source, and has a first extension portion located on the -X side with respect to the first light source and extending in a first direction parallel to the Y direction, a second extension portion located between the first light source and the second light source in the Y direction and extending from a first connection portion of the first extension portion in a second direction different from the first direction, and a third extension portion located on the +X side with respect to the second light source and extending from a second connection portion of the second extension portion in the first direction.

2. The light source group has a third light source arranged in the order of the first light source, the second light source and the third light source in the Y direction, The planar light source according to claim 1, wherein the first wiring comprises a fourth extension portion extending in a third direction different from the first direction from the third connection portion of the third extension portion, and a fifth extension portion located on the -X side with respect to the third light source and extending in the first direction from the fourth connection portion of the fourth extension portion.

3. The support has a second wiring positioned on the second surface opposite to the first surface, and extending in the X direction. The planar light source according to claim 1 or claim 2, wherein the second wiring is located between the first light source and the second light source in the Y direction.

4. The planar light source according to claim 3, wherein the length of the second wiring in the Y direction is longer than the length of the first extension in the X direction.

5. The planar light source according to claim 3, wherein, in a view from below, at least a portion of the second wiring overlaps with the first extension portion.

6. The planar light source according to claim 3, wherein the thickness of the second wiring is greater than the thickness of the first wiring.

7. The first light source is arranged in the first light guide member, The system further comprises a second light guide member on which the second light source is arranged, The first light guide member and the second light guide member are arranged with a gap between them. The planar light source according to claim 1 or claim 2, wherein, in a view from below, at least a portion of the first connecting portion and / or at least a portion of the second extension portion overlap with the gap.

8. The conductive member further comprises the first light source in contact with the first light source, The planar light source according to claim 1 or claim 2, wherein the length of the conductive member in the X direction is longer than the length of the first light source.

Images