Planar light source

Abstract

Provided is a planar light source capable of reducing luminance unevenness. The planar light source includes a support member, a light guide member having a first surface on the upper surface side of the support member, a second surface on the opposite side of the first surface, and a through-hole passing through from the first surface to the second surface, a light source portion having a light emitting element and a wavelength conversion member covering the upper surface and the side surface of the light emitting element, and disposed on the support member at the through-hole, a light-transmissive member disposed between the light source portion and the light guide member at the through-hole, and a light adjustment member disposed on the light source portion and the light-transmissive member, with the upper surface of the wavelength conversion member of the light source portion being located upward of the second surface of the light guide member.

Description

Technical Field

[0001] This invention relates to a planar light source. Background Technology

[0002] Planar light sources that combine light-emitting elements such as light-emitting diodes (LEDs) and light-guiding components are widely used, for example, in backlights of liquid crystal displays. For instance, Patent Document 1 discloses a light-emitting device comprising a light-guiding component having multiple through-holes and multiple light sources disposed on a substrate. Each of the multiple light sources is disposed within a through-hole of the light-guiding component.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2011-211085 Summary of the Invention

[0004] The purpose of this invention is to provide a planar light source that can reduce brightness unevenness.

[0005] According to one embodiment of the present invention, a planar light source includes: a support member; a light guide member having a first surface located on the upper surface side of the support member, a second surface on the opposite side of the first surface, and a through hole extending from the first surface to the second surface; a light source portion having a light-emitting element, a wavelength conversion member covering the upper surface and side surface of the light-emitting element, and the through hole disposed on the support member; a light-transmitting member disposed between the light source portion and the light guide member in the through hole; and a light adjustment member disposed above the light source portion and the light-transmitting member, wherein the upper surface of the wavelength conversion member of the light source portion is located above the second surface of the light guide member.

[0006] According to one embodiment of the present invention, a planar light source can reduce brightness unevenness. Attached Figure Description

[0007] Figure 1 This is a simplified top view of the planar light source according to the first embodiment.

[0008] Figure 2 yes Figure 1 A simplified sectional view of line II-II.

[0009] Figure 3 This is a simplified sectional view of the light source section.

[0010] Figure 4A This is a simplified top view showing an example of the recess 11 of the light guide component 10.

[0011] Figure 4B This is a simplified top view showing an example of the recess 11 of the light guide component 10.

[0012] Explanation of reference numerals in the attached figures

[0013] 10…light guide component; 20…light source; 30…light transmittance component; 40…light adjustment component; 200…support component; 300…area light source. Detailed Implementation

[0014] The embodiments will now be described with reference to the accompanying drawings. The drawings schematically illustrate the embodiments; therefore, the scale, spacing, or positional relationships of the components may sometimes be exaggerated, or parts of the components may be omitted. In this specification, the direction of the arrow along the Z-axis is defined as upward, and the direction opposite to the arrow along the Z-axis is defined as downward. The direction of the arrow along the X-axis is defined as the +X side, and the direction opposite to the arrow along the X-axis is defined as the -X side. The direction of the arrow along the Y-axis is defined as the +Y side, and the direction opposite to the arrow along the Y-axis is defined as the -Y side. Furthermore, as sectional views, end views showing only the cross-section are sometimes shown.

[0015] In the following description, the same reference numerals are often used to denote structural members that actually have the same function, and descriptions are omitted. Additionally, terms indicating specific directions or positions are sometimes used (e.g., "upper," "lower," and other terms including these). However, these terms are used only to clearly indicate the relative directions or positions of the referenced figures. If the relative directions or positions based on the terms "upper," "lower," etc., in the referenced figures are the same, then the configuration may not be the same as in the referenced figures in figures other than those of the present invention, actual articles, etc. In this specification, "parallel" includes not only the case where two lines, edges, surfaces, etc., do not intersect even when extended, but also the case where the angle between two lines, edges, surfaces, etc., is within 10°. In this specification, the positional relationship expressed as "upper" includes both contact and the case where, although not in contact, the position is above.

[0016] [First Implementation Method]

[0017] Reference Figures 1-3 The planar light source 300 is used to illustrate the implementation method. Figure 1 The attached diagram is a view from the emitting surface side of the planar light source 300. (See attached diagram.) Figure 1 As shown, the two directions parallel to and orthogonal to the emitting surface of the planar light source 300 are designated as the X direction and the Y direction. The direction orthogonal to both the X and Y directions is designated as the Z direction. In this specification, the plane parallel to the X and Y directions is sometimes referred to as the XY plane. Additionally, the Z direction, which is inclined laterally from the X direction at an angle greater than 0° and less than 360° in the XY plane, is sometimes referred to as the up-down direction.

[0018] The planar light source 300 includes a support member 200, a light guide member 10, a light source section 20, a light-transmitting member 30, and a light adjustment member 40. The light guide member 10 includes a first surface 101 located on the upper surface 200A side of the support member 200, a second surface 102 on the opposite side of the first surface 101, and a through hole 10H extending from the first surface 101 to the second surface 102. The light source section 20 has a light-emitting element and a wavelength conversion member covering the upper surface and side surface of the light-emitting element. The light source section 20 is disposed in the through hole 10H on the support member 200. The light-transmitting member 30 is disposed between the light source section 20 and the light guide member 10 in the through hole 10H. The light adjustment member 40 is disposed above the light source section 20 and the light-transmitting member 30. The upper surface of the wavelength conversion member 23 of the light source section 20 is located above the aforementioned second surface of the light guide member 10.

[0019] By arranging the light adjustment member 40 above the light source section 20 and the light-transmitting member 30, and positioning the upper surface of the wavelength conversion member 23 of the light source section 20 above the second surface of the light guide member 10, light from the light source section 20 can be efficiently directed to the light guide member 10, reducing excessive brightness in the area directly above the light source section. This reduces the uneven brightness of the planar light source 300.

[0020] The following details the components that constitute the planar light source 300.

[0021] (Light guide component 10)

[0022] like Figure 1 , Figure 2 As shown, the planar light source 300 includes a light guide member 10 having a through hole 10H for the light source section 20. The light guide member 10 is a member that has light transmittance for light generated by the light source section 20. The transmittance of the light guide member 10 relative to the peak wavelength of the light source section 20 is preferably 60% or more, and more preferably 80% or more.

[0023] The light guide member 10 has a first surface 101 located on the upper surface side of the support member 200, and a second surface 102 located on the opposite side of the first surface 101. The light guide member 10 continuously surrounds the light source portion 20 in a top view. In this embodiment, the light guide member 10 has a through hole 10H extending from the first surface 101 to the second surface 102. The light source portion 20 is disposed in the through hole 10H of the light guide member 10. In this embodiment, the through hole 10H is circular in a top view. The through hole 10H may also be elliptical, triangular, quadrilateral, hexagonal, octagonal, or other polygonal shapes in a top view.

[0024] The planar light source 300 may have one or more light guide components 10. Figure 1In the example shown, the planar light source 300 includes multiple light guide components 10, including a first light guide 10A, a second light guide 10B, a third light guide 10C, and a fourth light guide 10D. For example... Figure 1 As shown, in the X direction, the first light guide portion 10A and the second light guide portion 10B are adjacent. In the X direction, the third light guide portion 10C and the fourth light guide portion 10D are adjacent. In the Y direction, the first light guide portion 10A and the third light guide portion 10C are adjacent. In the Y direction, the second light guide portion 10B and the fourth light guide portion 10D are adjacent.

[0025] In this embodiment, each of the plurality of light guide components 10 is a different light-emitting region 300A. A light-emitting region 300A can be configured 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 also have a single light-emitting region 300A. Alternatively, a planar light source device with a larger area can be configured by arranging a plurality of planar light sources 300.

[0026] like Figure 1 As shown, the plurality of light guide components 10 are preferably arranged with a spacing 10G between each component. This reduces bending of the support member 200 caused by the difference in thermal expansion coefficients between the light guide component 10 and the support member 200. Consequently, the occurrence of cracking in the conductive components of the support member 200 can be reduced. The plurality of light guide components 10 are preferably arranged with a spacing 10G between each component.

[0027] Preferably, the light guide component 10 has a recess 11 that opens on the first surface 101 or the second surface 102. This makes it easier to increase the surface area of ​​the light guide component 10. As a result, it is easier to increase the amount of light extracted from the surface of the light guide component 10 to the outside of the light guide component 10, thus easily improving the light extraction efficiency of the planar light source 300.

[0028] The shape of the recess 11 in the light guide component 10 is not particularly limited. For example... Figure 1 As shown, the shape of the recess 11 in the light guide member 10 of this embodiment may also include a linear portion. Figure 4A In the example shown, the linear recess 11S is arranged parallel to the two sides constituting the outer shape of the light guide member 10. Figure 4B In the example shown, there is no straight recess parallel to the edges constituting the outline of the light guide member 10. Furthermore, in this specification, "linear" also includes straight lines, curves, or bent lines. For example, the shape of the recess 11 of the light guide member 10 in the top view may include V-shaped or L-shaped portions extending in two directions. The shape of the recess 11 of the light guide member 10 in the top view may also be circular, triangular, quadrilateral, hexagonal, or octagonal, etc.

[0029] Materials used for the light guide component 10 may include thermoplastic resins such as acrylic, polycarbonate, cyclic polyolefins, polyethylene terephthalate, or polyester, thermosetting resins such as epoxy resin or silicone, or glass. The light guide component 10 may also include phosphors or light scattering particles.

[0030] The thickness of the light guide component 10 is preferably 150 μm or more and 800 μm or less. The light guide component 10 may be composed of a single layer in the vertical direction or of a multi-layered laminate. When the light guide component 10 is composed of a laminate, a light-transmitting adhesive may be disposed between the layers. Different types of main materials may also be used for each layer of the laminate.

[0031] (Light Source Section 20)

[0032] The light source unit 20 is disposed in the through hole 10H of the light guide member 10. The planar light source 300 may have one or more light source units 20. Figure 1 In the example shown, the planar light source 300 includes multiple light source sections 20, including a first light source 20A, a second light source 20B, a third light source 20C, and a fourth light source 20D. The first light source 20A is disposed in a through-hole 10H of the first light guide section 10A. The second light source 20B is disposed in a through-hole 10H of the second light guide section 10B. The third light source 20C is disposed in a through-hole 10H of the third light guide section 10C. The fourth light source 20D is disposed in a through-hole 10H of the fourth light guide section 10D.

[0033] like Figure 3 As shown, the light source unit 20 includes a light-emitting element 21. The light-emitting element 21 includes a semiconductor stack. The semiconductor stack 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. Furthermore, the light-emitting element 21 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 portion of the lower surface of the light-emitting element 21. The light source unit 20 also includes a pair of positive and negative electrodes 22. The pair of positive and negative electrodes 22 constitute a portion of the lower surface of the light source unit 20. One of the electrodes 22 is electrically connected to the p-side electrode, and the other is electrically connected to the n-side electrode. Alternatively, the light source unit 20 may not include electrodes 22. In the case where the light source unit 20 does not include the pair of positive and negative electrodes 22, the n-side electrode and the p-side electrode of the light-emitting element 21 constitute a portion of the lower surface of the light source unit 20. Alternatively, the light source unit 20 may not have a substrate. This makes it easy to miniaturize the light source section 20 in the third direction (Z direction).

[0034] Figure 3The light source unit 20 shown includes one light-emitting element 21. Each light source unit 20, such as the first light source 20A, the second light source 20B, the third light source 20C, and the fourth light source 20D, may also include multiple light-emitting elements 21. The emission peak wavelengths of the multiple light-emitting elements contained in each light source unit 20 may be the same or different.

[0035] like Figure 3 As shown, the light source unit 20 also includes a wavelength conversion component 23. The wavelength conversion component 23 covers the upper surface and side surfaces of the light-emitting element 21. The wavelength conversion component 23 can be, for example, a component comprising a light-transmitting resin and a phosphor. For example, silicone resin or epoxy resin can be used as the light-transmitting resin. Furthermore, yttrium aluminum garnet-based phosphors (e.g., (Y, Gd)3(Al, Ga)5O) can be used as the phosphor. 12 Ce), lutetium aluminum garnet phosphors (e.g., Lu3(Al,Ga)5O) 12 Ce), terbium aluminum garnet phosphors (e.g., Tb3(Al,Ga)5O 12 Ce), CCA-based fluorophores (e.g., Ca), 10 (PO4)6C l2 Eu), SAE-based phosphors (e.g., Sr4Al) 14 O 25 Eu), chlorosilicate phosphors (e.g., Ca8MgSi4O) 16 C l2 β-silyl phosphors (e.g., (Ba, Sr, Ca, Mg)₂SiO₄:Eu), β-silyl phosphors (e.g., (Si, Al)₃(O, N)₄:Eu), or α-silyl phosphors (e.g., Ca(Si, Al)₂SiO₄:Eu). 12 (O, N) 16 Nitrogen oxide nitride phosphors such as Eu) and LSN-based phosphors (e.g., (La,Y)3Si6N) 11 Nitride-based phosphors such as 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), KSF-based phosphors (e.g., K2SiF6:Mn), and KSAF-based phosphors (e.g., K2(Si) 1-x Al x )F 6-xThe phosphors added to the wavelength conversion component 23 can be 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 with a perovskite structure (e.g., (Cs, FA, MA)(Pb, Sn)(F, Cl, Br, I)3, where FA and MA represent formamidinium and methylammonium, respectively); group II-VI quantum dots (e.g., CdSe); group III-V quantum dots (e.g., InP); or quantum dots with a chalcopyrite structure (e.g., (Ag, Cu)(In, Ga)(S, Se)2). One type of phosphor or multiple types of phosphors can be used as the phosphor added to the wavelength conversion component 23.

[0036] like Figure 2 As shown, the upper surface of the wavelength conversion member 23 of the light source unit 20 is located above the second surface 102 of the light guide member 10. Therefore, light emitted from the light source unit 20 is more easily incident in the lateral direction relative to the light guide member 10, and the light from the light source unit 20 is more easily propagated in the lateral direction. The height difference between the highest point of the upper surface of the wavelength conversion member 23 and the second surface 102 of the light guide member 10 is preferably, for example, 1 μm or more and 55 μm or less. The entire upper surface of the wavelength conversion member 23 may be located above the second surface 102 of the light guide member 10, or only a portion of its upper surface may be located above the second surface 102 of the light guide member 10. The upper surface of the wavelength conversion member 23 may be a flat surface, a curved surface, or a surface including steps, etc. When the upper surface of the wavelength conversion member 23 is a flat surface, the entire upper surface is located above the second surface 102 of the light guide member 10. When the upper surface of the wavelength conversion component 23 is a curved surface or a surface containing steps, the height difference between the highest part and the lowest part of the upper surface of the wavelength conversion component 23 is preferably 0.1 μm or more and 50 μm or less.

[0037] When the upper surface of the wavelength conversion member 23 is entirely curved, a portion of the curved upper surface can be positioned above the second surface 102 of the light guide member 10. In this case, it is preferable that the outer periphery of the upper surface of the wavelength conversion member 23 is positioned above the second surface 102 of the light guide member 10. This increases the area of ​​the side surface of the wavelength conversion member 23, thereby increasing the amount of light emitted from the side of the light source 20 toward the light guide member 10. Furthermore, increasing the surface area of ​​the upper surface of the wavelength conversion member 23 improves light extraction efficiency. When the upper surface of the wavelength conversion member 23 is a polygon or similar shape with multiple corners, the corners of the upper surface of the wavelength conversion member 23 can also be positioned above the second surface 102 of the light guide member 10. This improves light extraction efficiency and allows light traveling between the upper surface of the wavelength conversion member 23 and the light adjustment member 40 to propagate laterally from the outer periphery of the upper surface of the wavelength conversion member 23, excluding the corners.

[0038] In a top view, the upper surface of the wavelength conversion member 23 is, for example, a roughly rectangular shape with four corners. Preferably, the corners of the upper surface of the wavelength conversion member 23 are located above the center of the upper surface of the wavelength conversion member 23. In this way, since the area of ​​the side surface of the wavelength conversion member 23 can be increased, the amount of light emitted from the side of the light source 20 toward the light guide member 10 can be increased. In addition, since the surface area of ​​the upper surface of the wavelength conversion member 23 can be increased, the light extraction efficiency can be improved.

[0039] Preferably, the upper surface of the wavelength conversion component 23 has a curved surface with a central portion recessed downwards. As a result, the light propagating between the upper surface of the wavelength conversion component 23 and the light adjustment component 40 is reflected by the curved surface of the wavelength conversion component 23, thereby increasing the amount of light entering in the lateral direction and improving the light extraction efficiency.

[0040] Thus, the light source portion 20 having a portion of its upper surface located above the other portions of the wavelength conversion component 23 can be prepared in advance with such a structure, or a light source portion 20 with a flat upper surface can be prepared by removing a portion of that upper surface. Alternatively, after preparing a light source portion 20 with a flat upper surface and placing it in the through hole 10H, the wavelength conversion component 23 can be swollen by impregnating the resin of the light-transmitting component 30 disposed in the through hole 10H, thereby forming a wavelength conversion component 23 with a portion of its upper surface located above the other portions.

[0041] The shape of the wavelength conversion component 23 in the top view is not particularly limited. The shape of the wavelength conversion component 23 in the top view can be, for example, a triangle, quadrilateral, hexagon, or octagon. When the shape of the wavelength conversion component 23 in the top view is a quadrilateral, it is preferable that the sides constituting the outer shape of the wavelength conversion component 23 are inclined relative to the sides constituting the outer shape of the light guide component 10. Figure 1 In the example shown, the edge of the shape constituting the wavelength conversion component 23 is inclined at 45 degrees relative to the edge of the shape constituting the light guide component 10.

[0042] In the top view, the brightness of light emitted in a direction perpendicular to the edge of the wavelength conversion member 23 tends to be higher than the brightness of light emitted diagonally from the wavelength conversion member 23. Furthermore, in the top view, the quadrilateral shape of the light guide member 10 tends to make it difficult for light to spread to the four corners of the second surface 102. When the wavelength conversion member 23 is quadrilateral in the top view, the light source 20 is positioned relative to the light guide member 10 such that the diagonal connecting the corners of the second surface 102 intersects with the edge of the wavelength conversion member 23, and the edge of the wavelength conversion member 23 is positioned opposite the corner of the light guide member 10. This allows light emitted from the wavelength conversion member 23 to easily spread to the four corners of the light guide member 10. As a result, brightness unevenness in the light-emitting area 300A can be reduced.

[0043] The light source unit 20 may also include a cover member 24. The cover member 24 is disposed on the lower surface of the light-emitting element 21. The cover member 24 is configured such that the lower surface of the electrode 22 of the light source unit 20 is exposed from the cover member 24. The cover member 24 is also disposed on the lower surface of the wavelength conversion member 23 covering the side of the light-emitting element 21.

[0044] The cover component 24 is reflective of the light generated by the light-emitting element 21. The cover component 24 can be, for example, made of a resin component containing light-scattering particles. The resin component of the cover component 24 can be, for example, a thermoplastic resin such as acrylic resin, polycarbonate resin, cyclic polyolefin resin, polyethylene terephthalate resin, or polyester resin, or a thermosetting resin such as epoxy resin or silicone resin. The light-scattering particles of the cover component 24 can be, for example, particles such as titanium dioxide, silicon dioxide, aluminum oxide, zinc oxide, magnesium oxide, zirconium oxide, yttrium, calcium fluoride, magnesium fluoride, niobium pentoxide, barium titanate, tantalum pentoxide, barium sulfate, or glass.

[0045] (Light-transmitting component 30)

[0046] The light-transmitting component 30 is a component that is transparent to light generated by the light source unit 20. The light-transmitting component 30 has a first light-transmitting portion 31 and a second light-transmitting portion 32. Figure 2In the example shown, the first light-transmitting portion 31 and the second light-transmitting portion 32 are separate. Alternatively, the first light-transmitting portion 31 and the second light-transmitting portion 32 may be integrally formed from the same material. The transmittance of each of the first light-transmitting portion 31 and the second light-transmitting portion 32 relative to the peak wavelength of the light source portion 20 is preferably 60% or more, and more preferably 80% or more.

[0047] like Figure 2 As shown, the first light-transmitting portion 31 preferably contacts the side of the light source portion 20. This allows light from the light source portion 20 to easily enter the first light-transmitting portion 31. Furthermore, the first light-transmitting portion 31 preferably contacts the light guide member 10. This allows light from the light source portion 20 to easily enter the light guide member 10. Preferably, the first light-transmitting portion 31 is configured to expose at least a portion of the upper surface of the light source portion 20. This makes it easier to miniaturize the planar light source 300 in the third direction (Z direction) compared to the case where the first light-transmitting portion 31 covers the entire upper surface of the light source portion 20. The first light-transmitting portion 31 may also be configured to expose the entire upper surface of the light source portion 20. Alternatively, the first light-transmitting portion 31 may cover the entire upper surface of the light source portion 20. By covering the entire upper surface of the light source portion 20 with the first light-transmitting portion 31, adjusting the brightness of the area directly above the light source portion 20 becomes easier. For example, the brightness of the area directly above the light source portion 20 can be adjusted by changing the thickness of the first light-transmitting portion 31 covering the portion of the upper surface of the light source portion 20. Therefore, since brightness adjustment becomes easier, brightness unevenness of the planar light source 300 is easily reduced. When the first light-transmitting portion 31 covers the upper surface of the light source portion 20, the second light-transmitting portion 32 covers the upper surface of the light source portion 20 via the first light-transmitting portion 31. The first light-transmitting portion 31 can extend onto the second surface 102 of the light guide member 10. This allows adjustment of the brightness of the second surface 102 of the light guide member 10 near the through hole 10H.

[0048] The first light-transmitting portion 31, in the third direction (Z direction), can be composed of a single layer or a multi-layered laminate. Furthermore, the first light-transmitting portion 31 may also include phosphors and light-scattering particles. When the first light-transmitting portion 31 is a laminate, each layer may contain phosphors and / or light-scattering particles, or it may not contain them. For example, the first light-transmitting portion 31 may be composed of layers containing phosphors and layers not containing phosphors. The material used for the first light-transmitting portion 31 can, for example, be the same material as the resin component of the covering member 24.

[0049] The second light-transmitting portion 32 is disposed above the first light-transmitting portion 31. The second light-transmitting portion 32 may also be disposed above the light source portion 20. Preferably, the second light-transmitting portion 32 is in contact with the upper surface of the light source portion 20 and / or the upper surface of the first light-transmitting portion 31. Figure 2In the example shown, the second light-transmitting portion 32 is in contact with the upper surface of the light source portion 20. When the first light-transmitting portion 31 covers the upper surface of the light source portion 20, the second light-transmitting portion 32 can be configured to contact the upper surface of the first light-transmitting portion 31 disposed on the upper side of the light source portion 20.

[0050] Preferably, the second light-transmitting portion 32 extends onto the second surface 102 of the light guide member 10. This allows for adjustment of the brightness of the second surface 102 of the light guide member 10 near the through hole 10H. Furthermore, it is preferable that the light adjustment member 40 is disposed on the second light-transmitting portion 32 located on the second surface 102 of the light guide member 10. This reduces the possibility of excessive brightness in the area of ​​the second surface 102 of the light guide member 10 near the through hole 10H.

[0051] The material for the second light-transmitting part 32 can be, for example, the same material as the resin component of the covering part 24. Alternatively, a sheet-like optical transparent adhesive (OCA) can be used as the second light-transmitting part 32. The second light-transmitting part 32 may also include phosphors or light-scattering particles.

[0052] like Figure 2 As shown, the second light-transmitting portion 32 has a recess 32A (hereinafter referred to as the second light-transmitting recess). The inclusion of the second light-transmitting recess 32A in the second light-transmitting portion 32 increases the surface area of ​​the second light-transmitting portion 32. Consequently, the amount of light emitted from the second light-transmitting portion 32 to the outside can be increased.

[0053] Preferably, the second light-transmitting recess 32A is connected to the through hole 40A (hereinafter referred to as the light-adjusting through hole) of the light-adjusting component 40. Figure 2 In the example shown, the space inside the second light-transmitting recess 32A and the space inside the light-adjusting through-hole 40A are connected. This reduces the likelihood of light emitted from the second light-transmitting recess 32A being blocked by the light-adjusting member 40. That is, the light emitted from the second light-transmitting recess 32A is extracted to the outside of the planar light source 300 through the light-adjusting through-hole 40A. Therefore, the light extraction efficiency of the planar light source 300 is improved. In the top view, the second light-transmitting recess 32A overlaps with the light-adjusting through-hole 40A.

[0054] like Figure 2 As shown in the cross-sectional view, preferably, the maximum length L1 of the second light-transmitting recess 32A in the transverse direction is shorter than the maximum length L2 of the light-adjusting through-hole 40A in the transverse direction. In other words, preferably, the maximum length L2 of the light-adjusting through-hole 40A in the transverse direction is longer than the maximum length L1 of the second light-transmitting recess 32A in the transverse direction. This reduces the likelihood of light emitted from the light-transmitting recess 30A being blocked by the light-adjusting member 40.

[0055] At least a portion of the second light-transmitting recess 32A is located below the lower surface of the light-adjusting member 40. This shortens the distance from the second light-transmitting recess 32A to the light source 20 in the third direction (Z direction). Therefore, in this embodiment, where it is easier to increase the amount of light from the light source 20 extracted to the outside of the planar light source 300 through the second light-transmitting recess 32A, the wavelength conversion member 23 of the light source 20 is located above the second surface 102 of the light guide member 10, making it easier to shorten the distance from the second light-transmitting recess 32A to the light source 20 in the third direction (Z direction), and the effect becomes more significant.

[0056] The first light-transmitting portion 31 may have a recess 31A (hereinafter referred to as the first light-transmitting recess 31A). For example Figure 2 As shown, a first light-transmitting recess 31A is disposed around the light source section 20 in the lateral direction. In this way, light entering in the lateral direction from the light source section 20 passes through the first light-transmitting recess 31A and is easily extracted to the outside of the planar light source 300. Preferably, the depth of the first light-transmitting recess 31A is different from the depth of the second light-transmitting recess 32A. Furthermore, when the first light-transmitting recess 31A and the second light-transmitting recess 32A are defined by curved surfaces, it is preferable that their respective curved surfaces have different curvatures. For example, the curvature of the surface of the first light-transmitting recess 31A is defined to be smaller than the curvature of the surface of the second light-transmitting recess 32A. Therefore, light from the light source section 20 is reflected at different angles in the first light-transmitting recess 31A and the second light-transmitting recess 32A, thus improving light extraction efficiency.

[0057] Preferably, the depth of the second light-transmitting recess 32A is shallower than the depth of the first light-transmitting recess 31A. As a result, light from the light source 20 can easily spread laterally within the second light-transmitting recess 32.

[0058] (Light adjustment component 40)

[0059] The light adjustment component 40 has reflectivity and transmittance for light generated by the light source 20. A portion of the light emitted from the light source 20 is reflected by the light adjustment component 40, while the other portion passes through it. The transmittance of the light adjustment component 40 relative to the peak wavelength of the light source 20 is lower than the transmittance of the first transmittance portion 31 and the second transmittance portion 32 relative to the peak wavelength of the light source 20. For example, the transmittance of the light adjustment component 40 relative to the peak wavelength of the light source 20 is preferably 1% to 50% and more preferably 3% to 30%. The light adjustment component 40 can be constructed as a single layer or as a multilayer laminate.

[0060] The light adjustment component 40 is disposed on the upper side of the light source unit 20. In the top view, the light adjustment component 40 overlaps with the light source unit 20, and in this overlapping portion, the light adjustment component 40 is located on the upper side of the light source unit 20. By positioning the light adjustment component 40 on the upper side of the light source unit 20, it is possible to reduce excessive brightness in the area directly above the light source unit 20.

[0061] The light adjustment component 40 is disposed above the light-transmitting component 30. In the top view, the light adjustment component 40 overlaps with the first light-transmitting portion 31, and in this overlapping portion, the light adjustment component 40 is located above the first light-transmitting portion 31. By positioning the light adjustment component 40 above the first light-transmitting portion 31, it is possible to reduce excessive brightness in the area directly above the first light-transmitting portion 31.

[0062] A light adjustment component 40 is disposed above the second light-transmitting portion 32. In a top view, the light adjustment component 40 overlaps with the second light-transmitting portion 32, and in this overlapping portion, the light adjustment component 40 is located above the second light-transmitting portion 32. By positioning the light adjustment component 40 above the second light-transmitting portion 32, it is possible to reduce excessive brightness in the area directly above the second light-transmitting portion 32. Preferably, in the top view, the light adjustment component 40 is located above the second light-transmitting portion 32 in the overlapping portion of the first light-transmitting portion 31 and the second light-transmitting portion 32. This reduces excessive brightness in the area directly above the second light-transmitting portion 32, which is located above the first light-transmitting portion 31, where light from the side of the light source unit 20 is easily extracted.

[0063] The light adjustment component 40 may or may not have a light adjustment through hole 40A. Having a light adjustment through hole 40A makes it easier to adjust the brightness of the area directly above the light adjustment component 40. For example, the light from the light source 20 blocked by the light adjustment component 40 can be adjusted by changing the size and position of the light adjustment through hole 40A. Therefore, adjusting the brightness of the area directly above the light adjustment component 40 becomes easier, thus reducing brightness unevenness of the planar light source 300.

[0064] Preferably, the light adjustment through-hole 40A of the light adjustment component 40 is located away from the light source unit 20 in the top view. This reduces the possibility of excessive brightness in the area directly above the light source unit 20.

[0065] The shape of the light adjustment through hole 40A in the top view is not particularly limited. Figure 1 The light adjustment through-hole 40A in the top view shown is circular. However, the shape of the light adjustment through-hole 40A in the top view can also be elliptical, triangular, quadrilateral, hexagonal, octagonal, or other polygonal shapes. The shape of the light adjustment through-hole 40A in the top view can also include linear portions.

[0066] In the top view, it is preferable that a plurality of light-adjusting through holes 40A surround the light source section 20. This makes it easy to adjust the brightness of the planar light source 300 in the X and / or Y directions.

[0067] like Figure 2 As shown in the top view, the preferred light adjustment member 40 has a plurality of recesses 40B (hereinafter referred to as light adjustment recesses) that are recessed in the lateral direction. The light adjustment recesses 40B are provided on the outer edge of the light adjustment member 40. By having light adjustment recesses 30B, the brightness adjustment around the light adjustment member 40 becomes easier. For example, the light from the light source 20 blocked by the light adjustment member 40 can be adjusted by changing the size and position of the light adjustment recesses 40B. As a result, since the brightness adjustment around the light adjustment member 40 becomes easier, the brightness unevenness of the planar light source 300 is easily reduced. The size of the light adjustment recesses 40B is not particularly limited. The maximum length of the light adjustment recesses 40B in the X direction can also be shorter than the maximum length of the light adjustment through-hole 40A in the X direction. The maximum length of the light adjustment recesses 40B in the Y direction can also be shorter than the maximum length of the light adjustment through-hole 40A in the Y direction.

[0068] The light adjustment component 40 can be composed of a resin component and a reflector contained within the resin component. For example, the resin component of the light adjustment component 40 can be made of the same material as the resin component of the covering component 24. The material of the reflector of the light adjustment component 40 can be the same material as the light scattering particles of the covering component 24. The reflector of the light adjustment component 40 can also be a gas such as nitrogen or oxygen. Alternatively, the light adjustment component 40, as a reflector, can also include both light scattering particles and a gas.

[0069] (Support component 200)

[0070] The support body 100 supports the light source part 20 and the light guide member 10. The light guide member 10 is positioned so that its first surface 101 faces the upper surface of the support member 200 and is disposed on the support member 200.

[0071] The support member 200 has a wiring substrate 50. The wiring substrate 50 has an insulating substrate 51 and at least one wiring layer 52 disposed on at least one side of the insulating substrate 51. The insulating substrate 51 can be a rigid substrate or a flexible substrate. For the purpose of reducing the thickness of the planar light source, it is preferable that the insulating substrate 51 is a flexible substrate. The insulating substrate 51 can be composed of a single layer or a multilayer laminate in the third direction (Z direction). For example, the insulating substrate 51 can be composed of a single layer of flexible substrate or a laminate of multiple rigid substrates. The material used as the insulating substrate 51 can be, for example, a resin such as polyimide. The wiring layer 52 is a metal film, such as a copper film.

[0072] The support member 200 may also have a first adhesive layer 61 disposed on the wiring substrate 50, a reflective member 70 disposed on the first adhesive layer 61, and a second adhesive layer 62 disposed on the reflective member 70.

[0073] A first adhesive layer 61 is disposed between the wiring substrate 50 and the reflective member 70, bonding the reflective member 70 to the wiring substrate 50. The first adhesive layer 61 can, for example, be made of a resin component containing light-scattering particles. The resin component of the first adhesive layer 61 can, for example, be the same material as the resin component of the cover member 24. The light-scattering particles of the first adhesive layer 61 can, for example, be the same material as the light-scattering particles of the cover member 24. A sheet-like optical transparent adhesive can also be used as the first adhesive layer 61.

[0074] Preferably, the refractive index of the resin component of the first adhesive layer 61 is lower than that of the resin component of the reflective component 70. This allows a portion of the light entering the first adhesive layer 61 from the reflective component 70 to undergo total internal reflection at the interface between the reflective component 70 and the first adhesive layer 61. Consequently, light leakage downwards into the first adhesive layer 61 is reduced, thus improving the light extraction efficiency of the planar light source 300.

[0075] The reflective component 70 is disposed below the light guide component 10, below the light source unit 20, and below the light-transmitting component 30. The reflective component 70 is reflective of light generated by the light source unit 20. The reflective component 70 can be constructed from a resin component and a reflector contained within the resin component. For example, the resin component of the reflective component 70 can be made of the same material as the resin component of the covering component 24. The material of the reflector of the reflective component 70 can be the same material as the light-scattering particles of the covering component 24. The reflector of the reflective component 70 can also be a gas such as nitrogen or oxygen. Furthermore, the reflective component 70, as a reflector, can also include both light-scattering particles and a gas.

[0076] Preferably, the refractive index of the reflector of the reflector 70 is lower than the refractive index of the resin component of the reflector 70. This allows a portion of the light incident on the reflector 70 from the light source 20 to undergo total internal reflection at the interface between the resin component and the reflector of the reflector 70. Consequently, light leakage downwards from the reflector 70 is reduced, thus improving the light extraction efficiency of the planar light source 300.

[0077] When the refractive index of the reflector of the reflective component 70 is lower than the refractive index of the resin component of the reflective component 70, it is preferable that the refractive index of the resin component of the reflective component 70 is higher than the refractive index of the base material of the light guide component 10. This makes it easier to increase the refractive index difference between the resin component and the reflector of the reflective component 70. As a result, a portion of the light incident on the reflective component 70 from the light source 20 is more likely to undergo total internal reflection at the interface between the resin component and the reflector of the reflective component 70.

[0078] The second adhesive layer 62 is disposed between the reflective member 70 and the first surface 101 of the light guide member 10, thereby bonding the light guide member 10 to the reflective member 70. The light source portion 20 is disposed on the second adhesive layer 62 within the through hole 10H of the light guide member 10. The second adhesive layer 62 can be, for example, made of a resin component containing light scattering particles. The resin component of the second adhesive layer 62 can be, for example, made of the same material as the resin component of the cover member 24. The light scattering particles of the second adhesive layer 62 can be, for example, made of the same material as the light scattering particles of the cover member 24. A sheet-like transparent optical adhesive can also be used as the second adhesive layer 62.

[0079] Preferably, the refractive index of the resin component of the second adhesive layer 62 is lower than that of the base material of the light guide component 10. This allows a portion of the light entering the second adhesive layer 62 from the light guide component 10 to undergo total internal reflection at the interface between the light guide component 10 and the second adhesive layer 62. This reduces light leakage downwards into the second adhesive layer 62, thus improving the light extraction efficiency of the planar light source 300. Preferably, the refractive index of the resin component of the second adhesive layer 62 is lower than that of the base material of the first light-transmitting portion 31. This allows a portion of the light entering the second adhesive layer 62 from the first light-transmitting portion 31 to undergo total internal reflection at the interface between the first light-transmitting portion 31 and the second adhesive layer 62. This reduces light leakage downwards into the second adhesive layer 62, thus improving the light extraction efficiency of the planar light source 300.

[0080] The support member 200 also includes a conductive member 80. The conductive member 80 may comprise, for example, resin and metal particles contained within the resin. The resin used as the conductive member 80 may be, for example, epoxy resin or phenolic resin. The metal particles may be, for example, copper or silver particles.

[0081] The conductive component 80 has a connecting portion 81 and a wiring portion 82. The connecting portion 81 extends through the second adhesive layer 62, the reflective component 70, the first adhesive layer 61, and the insulating substrate 51 in a vertical direction. The wiring portion 82 is disposed on the surface of the wiring substrate 50 where the wiring layer 52 is disposed and is connected to the connecting portion 81. The connecting portion 81 and the wiring portion 82 can be integrally formed using the same material. A portion of the wiring portion 82 is connected to the wiring layer 52.

[0082] A pair of conductive components 80 are disposed separately from the positive and negative electrodes 22 of the light source section 20. The connecting portion 81 of one conductive component 80 is connected to the positive electrode 22 below the light source section 20, and the connecting portion 81 of the other conductive component 80 is connected to the negative electrode 22 below the light source section 20. The electrodes 22 of the light source section 20 are electrically connected to the conductive components 80 and the wiring layer 52.

[0083] The support member 200 also has an insulating layer 90. The insulating layer 90 is disposed on the lower surface of the wiring substrate 50 and covers the wiring layer 52. The material used as the insulating layer 90 can be, for example, epoxy resin, polyurethane resin or acrylic resin.

[0084] This specification includes the following implementation methods.

[0085] Item 1. A planar light source, comprising:

[0086] Support components;

[0087] A light guide component has a first surface located on the upper surface side of the support component, a second surface on the opposite side of the first surface, and a through hole extending from the first surface to the second surface.

[0088] The light source unit has a light-emitting element and a wavelength conversion component covering the upper surface and side surface of the light-emitting element, and the through hole is disposed on the support component.

[0089] A light-transmitting component is disposed between the light source portion and the light guide component in the through-hole; and

[0090] A light adjustment component is disposed above the aforementioned light source unit and the aforementioned light-transmitting component.

[0091] The upper surface of the wavelength conversion component of the light source is located above the second surface of the light guide component.

[0092] Item 2. The planar light source according to Item 1,

[0093] In the top view, the upper surface of the aforementioned wavelength conversion component is a roughly rectangular shape with multiple corners.

[0094] The corner of the upper surface of the wavelength conversion component is located above the center of the upper surface of the wavelength conversion component.

[0095] Item 3. The planar light source according to Item 1 or Item 2,

[0096] The upper surface of the aforementioned wavelength conversion component has a curved surface with a central portion recessed downwards.

[0097] Item 4. The planar light source according to any one of items 1 to 3,

[0098] The aforementioned light-transmitting component is positioned above the aforementioned wavelength conversion component.

[0099] Item 5. The planar light source according to any one of items 1 to 4,

[0100] The aforementioned light-transmitting component extends and is disposed on the aforementioned second surface of the aforementioned light-guiding component.

[0101] The aforementioned light adjustment component is disposed above the aforementioned light-transmitting component located on the aforementioned second surface of the aforementioned light guide component.

[0102] Item 6. The planar light source according to Item 2,

[0103] In a plan view, the shape of the light guide component is approximately rectangular, and the side constituting the shape of the wavelength conversion component is inclined relative to the side constituting the shape of the light guide component.

Claims

1. A planar light source, characterized in that, have: Support components; A light guide component has a first surface located on the upper surface side of the support component, a second surface on the opposite side of the first surface, and a through hole extending from the first surface to the second surface. The light source unit has a light-emitting element and a wavelength conversion component covering the upper surface and side surface of the light-emitting element, and the through hole is disposed on the support component. A light-transmitting component is disposed between the light source portion and the light guide component in the through-hole; and A light adjustment component is disposed above the aforementioned light source unit and the aforementioned light-transmitting component. The upper surface of the wavelength conversion component of the light source unit is located above the second surface of the light guide component. In the top view, the upper surface of the aforementioned wavelength conversion component is a roughly rectangular shape with multiple corners. The corner of the upper surface of the wavelength conversion component is located above the center of the upper surface of the wavelength conversion component.

2. The planar light source according to claim 1, characterized in that, The upper surface of the aforementioned wavelength conversion component has a curved surface with a central portion recessed downwards.

3. The planar light source according to claim 1, characterized in that, The aforementioned light-transmitting component is positioned above the aforementioned wavelength conversion component.

4. The planar light source according to claim 1, characterized in that, The aforementioned light-transmitting component extends and is disposed on the aforementioned second surface of the aforementioned light-guiding component. The aforementioned light adjustment component is disposed above the aforementioned light-transmitting component located on the aforementioned second surface of the aforementioned light guide component.

5. The planar light source according to claim 1, characterized in that, In a plan view, the shape of the light guide component is approximately rectangular, and the side constituting the shape of the wavelength conversion component is inclined relative to the side constituting the shape of the light guide component.

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