Surface light source

Abstract

The present invention provides a planar light source capable of reducing uneven brightness within a light-emitting surface. A first light adjustment component having reflectivity and light transmittance for light emitted by the light source is provided on the upper surface of the light source in a through hole of a light guide plate. A second light adjustment component having reflectivity and light transmittance for light emitted by the light source is provided on the first light adjustment component in isolation from the first light adjustment component. A first light-transmitting component is provided between the first light adjustment component and the second light adjustment component and between the side of the light source and the light guide plate, and the first light-transmitting component has a higher transmittance for light emitted by the light source than the first light adjustment component and the second light adjustment component.

Description

Technical Field

[0001] The invention relates to a planar light source. Background Art

[0002] Light-emitting modules that combine light-emitting diodes and light guide plates are widely used as planar light sources such as backlights of liquid crystal displays. In direct-below-type backlights where the light-emitting elements are arranged directly below the light guide plate, the brightness of the area near the light-emitting elements tends to be locally high.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2011-211085

[0006] Patent Document 2: International Publication No. 2010 / 070885 Summary of the invention

[0007] Problems that the invention will solve

[0008] An object of the present invention is to provide a planar light source capable of reducing uneven brightness within a light-emitting surface.

[0009] Means for solving problems

[0010] According to one embodiment of the present invention, a planar light source comprises: a light guide plate having a first surface, 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 arranged in the through hole of the light guide plate; a first light adjustment component, which is arranged on the upper surface of the light source in the through hole and has reflectivity and light transmittance for light emitted by the light source; a second light adjustment component, which is arranged on the first light adjustment component in isolation from the first light adjustment component and has reflectivity and light transmittance for light emitted by the light source; and a first light-transmitting component, which is arranged between the first light adjustment component and the second light adjustment component and between the side surface of the light source and the light guide plate, and has a higher transmittance for light emitted by the light source than the first light adjustment component and the second light adjustment component.

[0011] Effects of the Invention

[0012] According to the present invention, it is possible to provide a planar light source capable of reducing uneven brightness within a light emitting surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic top view of a planar light source according to one embodiment of the present invention.

[0014] Figure 2 yes Figure 1 Schematic cross-sectional view of line II-II.

[0015] Figure 3A This is a schematic cross-sectional view of a light source according to one embodiment of the present invention.

[0016] Figure 3B This is a schematic cross-sectional view of a light source according to one embodiment of the present invention.

[0017] Figure 4A This is a schematic cross-sectional view showing another example of the second light adjustment member in the planar light source according to the embodiment of the present invention.

[0018] Figure 4B This is a schematic cross-sectional view showing another example of the second light adjustment member in the planar light source according to the embodiment of the present invention.

[0019] Figure 5 It is a schematic cross-sectional view of a planar light source according to another embodiment of the present invention.

[0020] Figure 6 It is a schematic cross-sectional view of a planar light source according to still another embodiment of the present invention.

[0021] Figure 7 It is a schematic cross-sectional view of a planar light source according to still another embodiment of the present invention.

[0022] Figure 8 It is a schematic cross-sectional view of a planar light source according to still another embodiment of the present invention.

[0023] Fig. 9 It is a schematic cross-sectional view of a planar light source according to still another embodiment of the present invention.

[0024] Fig.10 It is a schematic top view of a planar light source according to still another embodiment of the present invention.

[0025] Fig.11 It is a schematic top view of a planar light source according to still another embodiment of the present invention.

[0026] Fig. 12A It is a schematic cross-sectional view showing another example of the light source according to the embodiment of the present invention.

[0027] Fig. 12B It is a schematic cross-sectional view showing still another example of the light source according to the embodiment of the present invention.

[0028] Fig. 12C It is a schematic cross-sectional view showing still another example of the light source according to the embodiment of the present invention.

[0029] Fig.13AIt is a schematic plan view showing still another example of the light source according to the embodiment of the present invention.

[0030] Fig. 13B It is a schematic plan view showing still another example of the light source according to the embodiment of the present invention.

[0031] Fig. 13C It is a schematic plan view showing still another example of the light source according to the embodiment of the present invention.

[0032] Fig.14A It is a schematic plan view showing still another example of the light source according to the embodiment of the present invention.

[0033] Fig. 14B yes Fig.14A Schematic cross-sectional view of the XIVB-XIVB line.

[0034] Fig.15A It is a schematic cross-sectional view showing still another example of the light source according to the embodiment of the present invention.

[0035] Fig. 15B It is a schematic cross-sectional view showing still another example of the light source according to the embodiment of the present invention.

[0036] Fig. 15C It is a schematic cross-sectional view showing still another example of the light source according to the embodiment of the present invention.

[0037] Description of Reference Numerals

[0038] 1…light emitting area, 10…light guide plate, 11…first surface, 12…second surface, 13…through hole, 20…light source, 21…light emitting element, 22…second light-transmitting member, 22a…light-transmitting resin, 22b…fluorescent substance, 23…electrode, 24, 25…covering member, 31…first light adjustment member, 31a…light-transmitting resin, 31b…light diffusion material, 32…second light adjustment member, 33…first light-transmitting member, 41…first light reflecting member, 42…second light reflecting member, 43…dividing member, 50…wiring substrate, 52…wiring layer, 100…planar light source DETAILED DESCRIPTION

[0039] Hereinafter, the embodiments will be described with reference to the drawings. In addition, in each of the drawings, the same reference numerals are given to the same elements.

[0040] Figure 1 It is a schematic top view of a planar light source 100 according to an embodiment of the present invention. Figure 1 FIG. 2 shows a top view of the light emitting surface of the planar light source 100. Figure 1 In FIG. 1 , two directions parallel to the light emitting surface of the planar light source 100 and orthogonal to each other are defined as an X direction and a Y direction.

[0041] The planar light source 100 has a plurality of light emitting regions 1 arranged in the X direction and the Y direction. The light emitting region 1 has a quadrilateral shape having two sides extending in the X direction and two sides extending in the Y direction.

[0042] One light emitting area 1 can be set as a driving unit for local dimming, for example. Figure 1 The surface light source 100 can also be composed of one light-emitting area 1 .

[0043] Figure 2 yes Figure 1 The schematic cross-sectional view taken along line II-II of is a schematic cross-sectional view showing a light-emitting region 1 .

[0044] The light emitting area 1 has a light guide plate 10 , a light source 20 , a first light adjustment component 31 , a second light adjustment component 32 , a first light transmissive component 33 , a first light reflective component 41 , a second light reflective component 42 , a partition component 43 , and a wiring substrate 50 .

[0045] The light guide plate 10 has light transmittance to light emitted from the light source 20. The light source 20 has a light emitting element 21. The light emitted from the light source 20 indicates light emitted from the light emitting element 21. When the light source 20 includes a fluorescent substance, the light emitted from the light source 20 also includes light emitted from the fluorescent substance.

[0046] As a material of the light guide plate 10 , for example, thermoplastic resins such as acrylic, polycarbonate, cyclic polyolefin, polyethylene terephthalate, and polyester, thermosetting resins such as epoxy and silicone, and glass can be used.

[0047] The light guide plate 10 has a first surface 11 that is a light emitting surface of the planar light source 100 and a second surface 12 opposite to the first surface 11. The light guide plate 10 has a through hole 13 that passes from the first surface 11 to the second surface 12. The light source 20 is disposed in the through hole 13.

[0048] The thickness of the light guide plate 10 is preferably not less than 200 μm and not more than 800 μm. The light guide plate 10 can be composed of a single layer in its thickness direction, or can be composed of a laminate of multiple layers. When the light guide plate 10 is composed of a laminate, a light-transmitting adhesive layer can be provided between the layers. Different types of main materials can be used for each layer of the laminate.

[0049] Figure 3A is a schematic cross-sectional view of the light source 20 .

[0050] The light source 20 includes a light emitting element 21. The light emitting element 21 has a semiconductor stacked structure. The light emitting element 21 includes, for example, Inx Al y Ga 1－x－y N (0≤x, 0≤y, x+y≤1), can emit blue light. As the light emitting element 21, an element that emits light other than blue (for example, ultraviolet light) may be used.

[0051] The upper surface and the side surfaces of the light emitting element 21 are covered by the second light transmissive member 22. The second light transmissive member 22 is made of a light transmissive resin 22a. The second light transmissive member 22 may include a fluorescent substance 22b dispersed in the light transmissive resin 22a.

[0052] The translucent resin 22a is, for example, a silicone resin or an epoxy resin. The phosphor 22b is excited by the light emitted by the light emitting element 21, and emits light of a wavelength different from the wavelength of the light emitted by the light emitting element 21. For example, as the phosphor 22b, a YAG phosphor, a β-sialon phosphor, a fluoride phosphor such as a KSF phosphor or an MGF phosphor, a nitride phosphor such as a CASN phosphor, etc. can be used. The phosphor can also be a quantum dot phosphor. The second translucent component 22 can include one type of phosphor or multiple types of phosphors. In addition, the second translucent component 22 can be constructed by stacking a single phosphor layer or multiple types of phosphor layers.

[0053] A pair of positive and negative electrodes 23 are provided on the lower surface side of the light emitting element 21. A covering member 24 is provided on the lower surface of the light emitting element 21. The surface of the electrode 23 ( Figure 3A The lower surface of the second light-transmitting member 22 (in the lower surface) is exposed from the covering member 24. The covering member 24 is also provided on the lower surface of the second light-transmitting member 22 covering the side surface of the light-emitting element 21.

[0054] The cover member 24 has reflectivity with respect to the light emitted from the light source 20. The cover member 24 is a white resin member containing titanium oxide, silicon dioxide, aluminum oxide, zinc oxide, glass, or the like as a light diffusion material, for example.

[0055] like Figure 2 As shown, a first light-transmitting component 33 is provided in the through hole 13 of the light guide plate 10. The first light-transmitting component 33 has light transmittance to the light emitted by the light source 20, and can be made of, for example, the same resin as the material of the light guide plate 10, or a resin having a small refractive index difference with the material of the light guide plate 10. Alternatively, glass can be used as the material of the first light-transmitting component 33.

[0056] The first light-transmitting component 33 is provided between the side surface of the light source 20 and the light guide plate 10. The side surface of the light source 20 and the first light-transmitting component 33, and the light guide plate 10 and the first light-transmitting component 33 are directly in contact. It is preferred that a space such as an air layer is not formed between the side surface of the light source 20 and the first light-transmitting component 33, and between the light guide plate 10 and the first light-transmitting component 33.

[0057] The light source 20 is arranged on the wiring substrate 50 in the through hole 13. The wiring substrate 50 has an insulating base material 51 and a wiring layer 52. The electrode 23 of the light emitting element 21 is bonded to the wiring layer 52 via a conductive bonding member 61. The bonding member 61 is, for example, solder. The first light-transmitting member 33 is also provided between the light source 20 and the wiring substrate 50 and around the bonding member 61.

[0058] The wiring substrate 50 is bonded to the second surface 12 side of the light guide plate 10. A first light reflective member 41 is provided between the second surface 12 of the light guide plate 10 and the wiring substrate 50. The first light reflective member 41 has reflectivity with respect to the light emitted by the light source 20. The first light reflective member 41 includes, for example, a sheet of white polyethylene terephthalate, which is a light diffusion material such as titanium oxide, silicon dioxide, aluminum oxide, zinc oxide, or glass, or a sheet of white polyethylene terephthalate in which a plurality of bubbles are formed.

[0059] Around the light source 20, a second light reflecting member 42 is provided on the surface of the wiring substrate 50 at the bottom of the through hole 13. The second light reflecting member 42 is a white resin member containing a light diffusing material such as titanium oxide, silicon dioxide, aluminum oxide, zinc oxide or glass.

[0060] A plurality of light-emitting areas 1 are provided on a light guide plate 10. Figure 1 As shown, the light guide plate 10 is provided with lattice-shaped grooves 14 extending in the X direction and the Y direction, and the grooves 14 partition the light emitting regions 1 .

[0061] like Figure 2 As shown, a partitioning member 43 is provided in the groove 14. The partitioning member 43 has reflectivity for the light emitted by the light source 20, and is, for example, a white resin member containing titanium oxide, silicon dioxide, aluminum oxide, zinc oxide, or glass as a light diffusion material. Alternatively, the partitioning member 43 may also be a metal member such as Al or Ag.

[0062] The partitioning member 43 suppresses light conduction between adjacent light emitting regions 1. For example, light conduction from a light emitting region 1 in a light emitting state to a light emitting region 1 in a non-light emitting state can be limited. Thus, local dimming can be performed with each light emitting region 1 as a driving unit.

[0063] exist Figure 2In the embodiment, the partition member 43 is filled in the groove 14. The partition member 43 may be formed in a film shape along the inner surface of the groove 14.

[0064] Figure 2 10 shows a bottomed groove 14 having an opening on the first surface 11 side and a bottom that does not reach the second surface 12, but the groove 14 may pass through from the first surface 11 to the second surface 12. Alternatively, it may be a bottomed groove 14 having an opening on the second surface 12 side and a bottom that does not reach the first surface 12. Alternatively, it may be a hollow groove provided inside the light guide plate 10.

[0065] A first light adjustment component 31 is provided on the upper surface of the light source 20 in the through hole 13. The first light adjustment component 31 is located in the through hole 13. The first light adjustment component 31 can be formed integrally with the light source 20. The first light adjustment component 31 and the upper surface of the light source 20 (at Figure 2 In the example shown, the upper surface of the second light-transmitting member 22 is in contact with the upper surface of the light source 20, directly covering the upper surface of the light source 20. Alternatively, another layer (such as a third light-transmitting member) may be interposed between the first light adjusting member 31 and the light source 20.

[0066] The second light adjusting member 32 is provided on the first light adjusting member 31 to be separated from the first light adjusting member 31. The first light adjusting member 31 and the second light adjusting member 32 have reflectivity and light transmittance with respect to the light emitted by the light source 20. The transmittance of the first light-transmitting member 33 with respect to the light emitted by the light source 20 can be set to 2 to 100 times the transmittance of the first light adjusting member 31 and the second light adjusting member 32.

[0067] The first light-transmitting member 33 is provided between the first light-adjusting member 31 and the second light-adjusting member 32, and the second light-adjusting member 32 is provided on the first light-transmitting member 33. The first light-transmitting member 33 has a higher transmittance to the light emitted by the light source 20 than the first light-adjusting member 31 and the second light-adjusting member 32.

[0068] like Figure 3A As shown, the first light adjustment member 31 includes a light-transmitting resin 31a and a light-diffusing material 31b dispersedly contained in the light-transmitting resin 31a. The light-transmitting resin 31a is, for example, a silicone resin or an epoxy resin. The light-diffusing material 31b is, for example, titanium oxide, silicon dioxide, aluminum oxide, zinc oxide, or glass. The second light adjustment member 32 is also the same as the first light adjustment member 31, and includes a light-transmitting resin and a light-diffusing material dispersedly contained in the light-transmitting resin.

[0069] The concentration of the light diffusing material of the second light adjusting member 32 is lower than that of the first light adjusting member 31. Therefore, the transmittance of the light emitted from the light source 20 of the second light adjusting member 32 is higher than that of the first light adjusting member 31.

[0070] Alternatively, the second light adjustment member 32 may be made thinner than the first light adjustment member 31 so that the transmittance of the second light adjustment member 32 is higher than the transmittance of the first light adjustment member 31 .

[0071] In addition, the first light adjusting member 31 and the second light adjusting member 32 may be metal members such as Al and Ag, or dielectric multilayer films, for example.

[0072] The first light adjustment member 31 covers the entire upper surface of the light source 20. The first light adjustment member 31 does not protrude from the upper surface of the light source 20. Therefore, the planar size of the first light adjustment member 31 is the same as that of the light source 20.

[0073] exist Figure 1 When the light emitting area 1 is viewed from above, the width of the second light adjustment component 32 is larger than the width of the first light adjustment component 31. The width here refers to the width in the X direction, the width in the Y direction, and the width in the direction inclined relative to these two directions. That is, the plane size of the second light adjustment component 32 is larger than the plane size of the first light adjustment component 31, and the second light adjustment component 32 is extended in a manner that indirectly covers the entire surface of the first light adjustment component 31 via the first light-transmitting component 33.

[0074] The outer edge 32a of the second light adjustment member 32 is located inside the edge 13a of the through hole 13 and is separated from the edge 13a of the through hole 13. That is, the second light adjustment member 32 does not cross the boundary between the light guide plate 10 and the first light transmissive member 33. Even if the difference in thermal expansion coefficient between the light guide plate 10 and the first light transmissive member 33 is large, since the second light adjustment member 32 is not located at the boundary therebetween, the second light adjustment member 32 is not affected by the stress caused by the difference in thermal expansion coefficient between the light guide plate 10 and the first light transmissive member 33. Thus, the second light adjustment member 32 can be prevented from peeling off, cracking, and the like.

[0075] The first light adjustment member 31 diffuses and reflects a portion of the light emitted by the light source 20 in the upward direction, and transmits the other portion. Thus, the brightness of the area directly above the light source 20 can be prevented from being extremely high compared to the brightness of other areas on the light-emitting surface of the light-emitting area 1. However, in this case, there is a risk that the area directly above the light source 20 becomes darker than other areas.

[0076] Therefore, in the present embodiment, the second light adjusting member 32 is provided on the first light adjusting member 31 to be separated from the first light adjusting member 31, and the first light transmissive member 33 having a higher transmittance than the first light adjusting member 31 and the second light adjusting member 32 is provided between the first light adjusting member 31 and the second light adjusting member 32. In the first light transmissive member 33 between the first light adjusting member 31 and the second light adjusting member 32, light emitted from the light source 20, light reflected by the second light reflecting member 42 in the through hole 13, and the like are guided, and part of the light guided by the first light transmissive member 33 is diffusely reflected by the second light adjusting member 32, and the other part is transmitted through the second light adjusting member 32.

[0077] As a result, the area directly above the light source 20 will not become too bright or too dark, and as a result, the brightness unevenness within the light-emitting surface of the light-emitting area 1 can be reduced.

[0078] Since a portion of the light emitted directly upward from the light source 20 is suppressed from transmitting by the first light adjustment component 31 , in order to suppress the area directly above the light source 20 from becoming too dark, it is desired that the transmittance of the second light adjustment component 32 is higher than that of the first light adjustment component 31 .

[0079] Furthermore, in order to suppress a sudden change in the in-plane brightness near directly above the light source 20 , it is desirable to make the width of the second light adjustment member 32 larger than the width of the first light adjustment member 31 in a plan view.

[0080] The cover member 24 provided on the lower surface of the light source 20 and the second light reflective member 42 provided on the surface of the wiring substrate 50 around the light source 20 can suppress the wiring substrate 50 near the light source 20 from being exposed to the light emitted from the light source 20, thereby preventing the deterioration of the wiring substrate 50. In addition, the light reflective cover member 24 and the second light reflective member 42 can reflect light on the light emitting surface of the light emitting region 1, that is, the first surface 11 side, thereby increasing the brightness of the light taken out from the first surface 11.

[0081] In the region between the first light reflective member 41 provided on the second surface 12 of the light guide plate 10 and the first surface 11, the light from the light source 20 is guided toward the dividing member 43 in the light guide plate 10 while repeating reflection by the first light reflective member 41 and reflection by the first surface 11. In the region between the first light reflective member 41 and the first surface 11, a part of the light toward the first surface 11 is taken out from the first surface 11 to the outside of the light guide plate 10.

[0082] Furthermore, as necessary, by making the first light-transmitting member 33 in the through hole 13 contain a fluorescent substance, the hue of the light-emitting color of the light-emitting region 1 can be corrected.

[0083] Figure 3BIt is a schematic cross-sectional view of another example of the light source 20 .

[0084] exist Figure 3B In the light source 20 shown, the side and lower surfaces of the light emitting element 21 are covered by the covering member 24. The second light transmissive member 22 is provided on the upper surface of the light emitting element 21. The second light transmissive member 22 is also provided on the side of the light emitting element 21 covered by the covering member 24.

[0085] exist Figure 2 In the illustrated example, the upper surface of the first light-transmitting member 33 is formed in a concave shape, and the upper surface of the second light adjustment member 32 is also formed along the upper surface of the first light-transmitting member 33 .

[0086] Figure 4A as well as Figure 4B It is a schematic cross-sectional view of a portion where the light source 20 is arranged in the planar light source according to the embodiment.

[0087] exist Figure 4A In the illustrated example, a convex portion is formed on the upper surface of the central portion of the second light adjustment member 32 , and the central portion of the second light adjustment member 32 is thicker than other portions.

[0088] exist Figure 4B In the example shown, the upper surface of the first light-transmitting member 33 is formed into a concave shape, and the upper surface of the second light-adjusting member 32 is a flat surface. Therefore, the thickness of the central portion of the second light-adjusting member 32 is thicker than other portions.

[0089] When the light guide plate 10 and the first light transmissive component 33 are made of the same material, or the difference between the thermal expansion coefficient of the light guide plate 10 and the thermal expansion coefficient of the first light transmissive component 33 is small, as shown in FIG. Figure 5 As shown, the second light adjusting member 32 may be formed so as to straddle the boundary between the light guide plate 10 and the first light transmissive member 33. The outer edge 32a of the second light adjusting member 32 is located outside the edge 13a of the through hole 13.

[0090] Figure 6 It is a schematic cross-sectional view of a planar light source according to still another embodiment of the present invention.

[0091] exist Figure 6 In the example shown, the side wall 13b of the through hole 13 is inclined relative to the first surface 11 and the second surface 12 of the light guide plate 10. The side wall 13b of the through hole 13 forms an obtuse angle with the first surface 11, and the side wall 13b of the through hole 13 forms an acute angle with the second surface 12. The lower end of the side wall 13b of the through hole 13 is located closer to the light source 20 than the upper end of the side wall 13b of the through hole 13. Therefore, the first light reflective member 41 provided on the second surface 12 can be brought closer to the light source 20, and the reflection component of the first light reflective member 41 can be increased to improve the brightness.

[0092] Figure 7 It is a schematic cross-sectional view of a planar light source according to still another embodiment of the present invention.

[0093] Figure 7 The wiring substrate 50 of the planar light source shown has an insulating base 51, a wiring layer 52, and a cover layer 53. The wiring layer 52 is provided on the lower surface of the insulating base 51, and the surface of the wiring layer 52 is covered by the cover layer 53. The cover layer 53 is, for example, a resin layer.

[0094] Light reflective member 44 is provided on wiring board 50. Light reflective member 44 is a sheet of white polyethylene terephthalate containing titanium oxide, silicon dioxide, aluminum oxide, zinc oxide, or glass as a light diffusion material, or white polyethylene terephthalate with a plurality of bubbles formed therein.

[0095] The light reflective member 44 is provided between the insulating base material 51 of the wiring substrate 50 and the second surface 12 of the light guide plate 10. Furthermore, the light reflective member 44 is provided between the lower surface of the first light transmissive member 33 in the through hole 13 and the insulating base material 51 of the wiring substrate 50.

[0096] The light reflecting member 44 is provided between the lower surface of the light source 20 and the insulating base material 51 of the wiring board 50. The light source 20 is bonded to the upper surface of the light reflecting member 44 by the bonding member 63. The bonding member 63 is, for example, a resin member.

[0097] A bonding member 62 is provided to penetrate the light reflective member 44, the insulating base material 51, and the wiring layer 52 in the region directly below the light source 20. The bonding member 62 connects the electrode of the light emitting element 21 and the wiring layer 52. The bonding member 62 is, for example, solder.

[0098] The bonding member 62 and a part of the wiring layer 52 in the vicinity of the bonding member 62 are exposed from the cover layer 53. The bonding member 62 and the exposed part of the wiring layer 52 are covered with the resist 54.

[0099] like Figure 8 As shown, a white adhesive sheet 45 may be provided on the insulating base material 51 of the wiring substrate 50, and the light source 20 may be arranged on the adhesive sheet 45. Between the adhesive sheet 45 and the second surface 12 of the light guide plate 10, a first light reflective member 41 is provided.

[0100] Fig. 9 It is a schematic cross-sectional view of a planar light source according to still another embodiment of the present invention.

[0101] The light source 20 includes a light emitting element 21 and a second light transmissive member 122 covering the upper surface and side surfaces of the light emitting element 21. The second light transmissive member 122 is, for example, a light transmissive resin and does not contain a phosphor. A phosphor sheet 71 is provided on the first surface 11 of the light guide plate 10. The phosphor sheet 71 is a resin sheet containing a phosphor.

[0102] like Figure 1 As shown, the first surface 11 of a light emitting region 1 divided by the dividing member 43 (groove 14) is formed into a quadrilateral having four corners, and the planar shape of the light source 20 and the second light adjustment member 32 is also formed into a quadrilateral having four corners. Figure 1 In the plan view shown, the corners of the light source 20 and the second light adjustment member 32 face the corners of the first surface 11 .

[0103] Alternatively, you can Fig.10 As shown in the top view, from Figure 1 The second light adjustment member 32 is rotated 45 degrees, for example, from the state of the first surface 11 so that the diagonal line connecting the corners of the first surface 11 intersects with the side surface (or side) of the second light adjustment member 32. Figure 1 In the embodiment, the corners of the second light adjusting member 32 are not located on the diagonal line connecting the corners of the first surface 11. Thus, the light emitted from the light source 20 can be easily diffused to the four corners of the light emitting region 1.

[0104] Furthermore, the light source 20 may also be arranged rotated 45 degrees so that a diagonal line connecting the corners of the first surface 11 intersects with a side surface (or side) of the light source 20 .

[0105] In addition, if Fig.11 As shown, the corners of the second light adjustment component 32 may also be rounded.

[0106] The semiconductor stacked structure of the light emitting element 21 may include at least one light emitting layer capable of emitting light in the above-mentioned light emitting color. For example, the semiconductor stacked structure may include one or more light emitting layers between an n-type semiconductor layer and a p-type semiconductor layer. In addition, the light emitting layer may be a structure having a single active layer such as a double heterostructure or a single quantum well structure (SQW), or a structure having a group of active layers such as a multiple quantum well structure (MQW).

[0107] In addition, the semiconductor stacking structure may also include multiple light-emitting layers. For example, the semiconductor stacking structure may be a structure including multiple light-emitting layers between an n-type semiconductor layer and a p-type semiconductor layer, or a structure including an n-type semiconductor layer, a light-emitting layer, and a p-type semiconductor layer repeatedly and sequentially. Multiple light-emitting layers may include light-emitting layers with different light-emitting colors, or may include light-emitting layers with the same light-emitting colors. In addition, the same light-emitting color refers to the range of light-emitting colors that can be regarded as the same in use, for example, there may be a deviation of about a few nm at the main wavelength. As a combination of light-emitting colors, it can be appropriately selected. For example, in the case where the semiconductor stacking structure includes two light-emitting layers, as a combination of light-emitting colors, 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, etc. can be listed.

[0108] In addition, the light source may include a plurality of light emitting elements having different emission peak wavelengths. Figures 12A to 15C , a light source including a plurality of light-emitting elements having different emission peak wavelengths is described.

[0109] Fig. 12A The light source 20A shown includes a first light emitting element 21B and a second light emitting element 21G arranged next to the first light emitting element 21B. The first light emitting element 21B emits blue light, and the second light emitting element 21G emits green light.

[0110] The light source 20A further includes a phosphor layer 22R. The phosphor layer 22R covers the upper surface of the first light-emitting element 21B, the side surface of the first light-emitting element 21B, the upper surface of the second light-emitting element 21G, and the side surface of the second light-emitting element 21G. The phosphor layer 22R seals the first light-emitting element 21B and the second light-emitting element 21G together. The phosphor layer 22R includes a light-transmitting resin and a red phosphor dispersed in the light-transmitting resin. The red phosphor is excited by the light emitted by the first light-emitting element 21B and the second light-emitting element 21G, and emits red light.

[0111] The light source 20A further includes a cover member 24 and a first light adjustment member 31 configured in the same manner as in the above-described embodiment. The first light adjustment member 31 is provided on the fluorescent layer 22R. The cover member 24 is arranged on the lower surface of the first light emitting element 21B so that the surface of the electrode 23 of the first light emitting element 21B is exposed, and is arranged on the lower surface of the second light emitting element 21G so that the surface of the electrode 23 of the second light emitting element 21G is exposed.

[0112] Fig. 12B The light source 20B and Fig. 12CThe light source 20C shown is also similar to the light source 20A, and includes a first light emitting element 21B, a second light emitting element 21G, a fluorescent layer 22R, a cover member 24 , and a first light adjusting member 31 .

[0113] exist Fig. 12B In the light source 20B shown, the cover member 24 covers the lower surface and side surfaces of the first light emitting element 21B, the lower surface and side surfaces of the second light emitting element 21G, and is also disposed between the first light emitting element 21B and the second light emitting element 21G.

[0114] The light source 20B further includes a translucent member 22C disposed on the first light emitting element 21B, the second light emitting element 21G, and the cover member 24. The translucent member 22C is, for example, a translucent resin member. The phosphor layer 22R is disposed on the first light emitting element 21B, but not on the second light emitting element 21G. The translucent member 22C covers the phosphor layer 22R.

[0115] exist Fig. 12C In the light source 20C shown, the cover member 24 covers the lower surface of the first light emitting element 21B, the side surface of the first light emitting element 21B, the lower surface of the second light emitting element 21G, and the side surface of the second light emitting element 21G. In addition, the light source 20C includes a light-transmitting member 22C disposed on the first light emitting element 21B, the second light emitting element 21G, and the cover member 24. The fluorescent layer 22R is disposed on the light-transmitting member 22C, and the first light adjustment member 31 is disposed on the fluorescent layer 22R.

[0116] The number of first light emitting elements 21B included in one light source is not limited to one, and the number of second light emitting elements 21G included in one light source is not limited to one. A plurality of light emitting elements may be connected in series or in parallel. In addition, a plurality of light emitting elements may be driven independently.

[0117] When viewed from above, the area of ​​the first light-emitting element 21B can be the same as, larger than, or smaller than the area of ​​the second light-emitting element 21G. When the first light-emitting element 21B and the second light-emitting element 21G are connected in series, the light from the light-emitting device can be set to a target hue by appropriately setting the area of ​​the first light-emitting element 21B and / or the area of ​​the second light-emitting element 21G when viewed from above. When viewed from above, the area of ​​the second light-emitting element 21G is preferably larger than the area of ​​the first light-emitting element 21B. Generally speaking, the luminous efficiency of the second light-emitting element 21G that emits green light is lower than that of the first light-emitting element 21B that emits blue light. Therefore, by making the area of ​​the second light-emitting element 21G larger than the area of ​​the first light-emitting element 21B when viewed from above, the light from the second light-emitting element 21G, which has a lower luminous efficiency than the first light-emitting element 21B, can be enhanced.

[0118] Figures 13A to 13C It is a schematic plan view showing an arrangement example of the first light emitting element 21B and the second light emitting element 21G.

[0119] exist Fig.13A In the example shown, four second light emitting elements 21G are arranged around one first light emitting element 21B. Fig. 13B In the example shown, four first light emitting elements 21B are arranged around one second light emitting element 21G.

[0120] exist Fig. 13C In the example shown, a plurality of first light emitting elements 21B and a plurality of second light emitting elements 21G are arranged in a matrix. The first light emitting elements 21B and the second light emitting elements 21G are arranged alternately in the X direction, and the first light emitting elements 21B and the second light emitting elements 21G are arranged alternately in the Y direction orthogonal to the X direction. Four second light emitting elements 21G are arranged around the first light emitting element 21B that is not located at the end, and four first light emitting elements 21B are arranged around the second light emitting element 21G that is not located at the end.

[0121] exist Figures 12A to 13C In the light source shown, the combination of luminous colors of multiple light-emitting elements contained in one light source is not limited to blue light and green light, and may include blue light and blue light, green light and green light, red light and red light, ultraviolet light and ultraviolet light, blue light and red light, or green light and red light, etc.

[0122] Fig.14AThe light source 20D shown includes a first lead 91, a second lead 92, and a third lead 93. In addition, the light source 20D includes a first light emitting element 21B that emits blue light, and a second light emitting element 21G that is disposed on the first light emitting element 21B and emits green light. In addition, the light source may also change the position of the first light emitting element and the position of the second light emitting element. For example, the light source may also include a second light emitting element that emits green light, and a first light emitting element that is disposed on the second light emitting element and emits blue light.

[0123] The first lead 91 is separated from the second lead 92. The first lead 91 is separated from the third lead 93. The second lead 92 is separated from the third lead 93.

[0124] Fig. 14B yes Fig.14A Schematic cross-sectional view of the XIVB-XIVB line. Fig.14A In, only the picture is shown Fig. 14B The light source 20D shown includes a first light emitting element 21B, a second light emitting element 21G, a first lead 91, a second lead 92, a third lead 93, a positive electrode 81p, a negative electrode 81n, and a wire 82a.

[0125] The first light emitting element 21B includes a positive electrode 23p and a negative electrode 23n. The positive electrode 23p and the negative electrode 23n are arranged on the lower surface of the first light emitting element 21B. The second light emitting element 21G includes a positive electrode 81p and a negative electrode 81n. The positive electrode 81p and the negative electrode 81n are arranged on the upper surface of the second light emitting element 21G.

[0126] The positive electrode 23p of the first light emitting element 21B is bonded to the first lead 91. The negative electrode 23n of the first light emitting element 21B is bonded to the third lead 93. The positive electrode 81p of the second light emitting element 21G is connected to the third lead 93 by a wire 82a. The negative electrode 81n of the second light emitting element 21G is connected to the second lead 92 by a wire 82b.

[0127] The side surfaces of the leads 91 to 93 are covered by the cover member 24 . The lower surfaces of the leads 91 to 93 are exposed from the cover member 24 .

[0128] A phosphor layer 22R is disposed on each of the lead wires 91 to 93 and the cover member 24. The phosphor layer 22R covers the first light emitting element 21B, the second light emitting element 21G, the wires 82a and 82b, and the electrodes 23p, 23n, 81p, and 81n. The first light adjusting member 31 is disposed on the phosphor layer 22R.

[0129] The direction of the current flow in the light source 20D is schematically indicated by a hollow arrow. The current flows from the first lead 91 to the second lead 92 via the positive electrode 23p of the first light-emitting element 21B, the light-emitting layer of the first light-emitting element 21B, the negative electrode 23n of the first light-emitting element 21B, the third lead 93, the wire 82a, the positive electrode 81p of the second light-emitting element 21G, the light-emitting layer of the second light-emitting element 21G, the negative electrode 81n of the second light-emitting element 21G, and the wire 82b.

[0130] The lower surface of the first light emitting element 21B may also have a holding portion electrically insulated from the light emitting layer of the first light emitting element 21B. The holding portion of the first light emitting element 21B is in contact with the first lead 91, the second lead 92, the third lead 93 and / or the covering member 24, so that the first light emitting element 21B can be prevented from tilting when the first light emitting element 21B is arranged on the leads.

[0131] Figures 15A to 15C The light source shown also includes a stacked structure of a first light emitting element 21B emitting blue light and a second light emitting element 21G emitting green light. The positions of the first light emitting element and the second light emitting element may be changed. The second light emitting element 21G is arranged on the first light emitting element 21B via a light-transmitting adhesive member 26.

[0132] The first light emitting element 21B includes a positive electrode 23p and a negative electrode 23n. The positive electrode 23p and the negative electrode 23n are arranged on the lower surface of the first light emitting element 21B. The second light emitting element 21G includes a positive electrode 27p and a negative electrode 27n. The positive electrode 27p and the negative electrode 27n are arranged on the lower surface of the second light emitting element 21G.

[0133] exist Fig.15A In the light source 20E shown, a cover member 24 is disposed on the lower surface of the first light emitting element 21B. On the lower surface of the cover member 24, a first wiring 28a, a second wiring 28b, and a third wiring 28c are disposed to be separated from each other.

[0134] The fluorescent material layer 22R is arranged on the cover member 24 so as to cover the first light emitting element 21B and the second light emitting element 21G. The first light adjustment member 31 is arranged on the fluorescent material layer 22R.

[0135] The lower surface of the positive electrode 23p of the first light-emitting element 21B is connected to the first wiring 28a. The lower surface of the negative electrode 23n of the first light-emitting element 21B is connected to the second wiring 28b. The positive electrode 27p of the second light-emitting element 21G penetrates the phosphor layer 22R and the cover member 24 and is connected to the second wiring 28b. Therefore, the negative electrode 23n of the first light-emitting element 21B and the positive electrode 27p of the second light-emitting element 21G are electrically connected through the second wiring 28b. The negative electrode 27n of the second light-emitting element 21G penetrates the phosphor layer 22R and the cover member 24 and is connected to the third wiring 28c.

[0136] Current flows from the first wiring 28a to the third wiring 28c via the positive side electrode 23p of the first light-emitting element 21B, the light-emitting layer of the first light-emitting element 21B, the negative side electrode 23n of the first light-emitting element 21B, the second wiring 28b, the positive side electrode 27p of the second light-emitting element 21G, the light-emitting layer of the second light-emitting element 21G and the negative side electrode 27n of the second light-emitting element 21G.

[0137] exist Fig. 15B In the light source 20F shown in the figure, the covering member 24 is arranged so as to cover the electrodes 27 p and 27 n of the first light emitting element 21B and the second light emitting element 21G and the adhesive member 26 .

[0138] exist Fig. 15C In the light source 20G shown, the second light emitting element 21G is also further covered by the covering member 24. The fluorescent material layer 22R is arranged on the second light emitting element 21G via a light-transmitting adhesive member 29.

[0139] Above, the embodiments of the present invention are described with reference to specific examples. However, the present invention is not limited to these specific examples. All modes that can be appropriately designed and changed by those skilled in the art based on the above-mentioned embodiments of the present invention also belong to the scope of the present invention as long as they include the gist of the present invention. In addition, it can be understood that within the scope of the thought of the present invention, as long as they are various variations and modifications that can be thought of by those skilled in the art, these variations and modifications also belong to the scope of the present invention.

Claims

1. A planar light source, characterized in that: have: A light guide plate having a first surface, a second surface opposite to the first surface, and a through hole penetrating from the first surface to the second surface; a light source, disposed in the through hole of the light guide plate; A first light adjustment component, which is disposed on the upper surface of the light source in the through hole and has reflectivity and light transmittance for the light emitted by the light source; a second light adjustment component, which is isolated from the first light adjustment component and is disposed on the first light adjustment component, and has reflectivity and light transmittance for the light emitted by the light source; as well as A first light-transmitting component is a resin disposed in the through hole and is disposed between the first light adjustment component and the second light adjustment component and between the side of the light source and the light guide plate. The first light-transmitting component has a higher transmittance to the light emitted by the light source than the first light adjustment component and the second light adjustment component.

2. The planar light source according to claim 1, characterized in that: The transmittance of the second light adjusting member with respect to the light emitted by the light source is higher than the transmittance of the first light adjusting member with respect to the light emitted by the light source.

3. The planar light source according to claim 2, characterized in that: The first light adjusting member and the second light adjusting member include a light-transmitting resin and a light diffusing material contained in the light-transmitting resin. The concentration of the light diffusing material of the second light adjusting member is lower than the concentration of the light diffusing material of the first light adjusting member.

4. The planar light source according to any one of claims 1 to 3, characterized in that: In a plan view, the width of the second light adjustment member is greater than the width of the first light adjustment member.

5. The planar light source according to any one of claims 1 to 3, characterized in that: The first light-transmitting member includes a fluorescent substance.

6. The planar light source according to any one of claims 1 to 3, characterized in that: The outer edge of the second light adjusting member is located inside the edge of the through hole and is spaced apart from the edge of the through hole.

7. The planar light source according to any one of claims 1 to 3, characterized in that: The light source has: a light emitting element having an electrode on a lower surface side; and a second light-transmitting member covering the upper surface and side surfaces of the light-emitting element, The first light adjustment member is provided on the upper surface of the second light-transmitting member.

8. The planar light source according to claim 7, characterized in that: The second light-transmitting member contains a fluorescent substance.

9. The planar light source according to any one of claims 1 to 3, characterized in that: The light source has: a light emitting element having an electrode on a lower surface side; a second light-transmitting member covering an upper surface of the light-emitting element; as well as a covering member that covers the side surface of the light emitting element and has reflectivity for the light emitted by the light source, The first light adjustment member is provided on the upper surface of the second light-transmitting member.

10. The planar light source according to claim 9, characterized in that: The second light-transmitting member contains a fluorescent substance.

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