JP7185151B2 - surface emitting light source - Google Patents

Description

The present invention relates to surface emitting light sources.

2. Description of the Related Art A direct type surface emitting light source having a structure in which a plurality of light emitting elements are arranged is known as a backlight source for displays of personal computers, tablets, and the like. Direct-type surface-emitting light sources have been developed in which a light-emitting surface is divided into a plurality of light-emitting regions, and lighting and extinguishing of these light-emitting regions are independently controlled (see, for example, Patent Document 1).

JP 2018-101521 A

In the surface light source device of Patent Literature 1, grooves are formed on the lower surface of the light guide plate at the positions of the outer edges of each light emitting region centered on each of the plurality of light sources. The groove has, for example, a reflective layer inside. The grooves are intended to avoid a decrease in contrast ratio due to leakage of light between the light emitting regions. However, due to total reflection on the upper surface of the light guide plate, there are components that enter adjacent light emitting regions. The light that has entered the light emitting region in which the light source is turned off is emitted to the outside of the light emitting region by repeating reflection inside the region. The light emitted to the outside of the light emitting region also includes light reflected by the groove surrounding the light source in the off state. Such reflected light causes abrupt changes in brightness in displaying an image and sometimes obscures the display on the display.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a surface emitting light source that suppresses a sudden change in luminance of leaked light from a lit area to an adjacent unlit area.

In order to achieve the above objects, a surface emitting light source according to an embodiment of the present invention comprises:
A surface-emitting light source having a plurality of light-emitting regions each including a light source and each of which can be independently lit,
each light emitting region is adjacent,
a light guide portion included in the plurality of adjacent light emitting regions and covering the plurality of light sources;
a light reflective member provided below the light guide;
with
The light reflective member has a first wall provided on the outer periphery of each light emitting region,
The first wall portion is composed of one or more unit first wall portions corresponding to the light sources located on the outer periphery of each light emitting region,
The height of the central portion of the unit first wall portion located in the two adjacent light emitting regions is lower than that of the both end portions.

According to a surface emitting light source according to an embodiment of the present invention, it is possible to provide a surface emitting light source that suppresses a sudden change in brightness of leaked light from a lit area to an adjacent unlit area.

It is a figure showing the surface emitting light source concerning one embodiment of the present invention. FIG. 2 is a top view of a light-emitting area included in the surface-emitting light source shown in FIG. 1; FIG. 3 is a cross-sectional view of the light emitting region shown in FIG. 2 taken along line AA; It is a sectional view of the luminous field of the surface emitting light source concerning an embodiment. It is the figure which expanded a part of sectional drawing shown in FIG. 3 is a perspective view of a unit first wall provided in the light emitting region shown in FIG. 2; FIG. It is a modification of the unit first wall shown in FIG. 6A. It is a modification of the unit first wall shown in FIG. 6A. It is a modification of the unit first wall shown in FIG. 6A. It is a partially enlarged schematic cross-sectional view showing an example of the manufacturing process of the surface emitting light source according to the embodiment. It is a partially enlarged schematic plan view showing an example of the manufacturing process of the surface emitting light source according to the embodiment. It is a partially enlarged schematic plan view showing an example of the manufacturing process of the surface emitting light source according to the embodiment. It is a partially enlarged schematic cross-sectional view showing an example of the manufacturing process of the surface emitting light source according to the embodiment. It is a partially enlarged schematic cross-sectional view showing an example of the manufacturing process of the surface emitting light source according to the embodiment. It is a partially enlarged schematic cross-sectional view showing an example of the manufacturing process of the surface emitting light source according to the embodiment. It is a partially enlarged schematic cross-sectional view showing an example of the manufacturing process of the surface emitting light source according to the embodiment. It is a partially enlarged schematic cross-sectional view showing an example of the manufacturing process of the surface emitting light source according to the embodiment. It is a partially enlarged schematic cross-sectional view showing an example of the manufacturing process of the surface emitting light source according to the embodiment. It is a partially enlarged schematic cross-sectional view showing an example of the manufacturing process of the surface emitting light source according to the embodiment. It is a sectional view of the luminous field of the surface emitting light source concerning an embodiment. It is a sectional view of the luminous field of the surface emitting light source concerning an embodiment. It is a sectional view of the luminous field of the surface emitting light source concerning an embodiment. It is a top view of the light emitting module of the surface emitting light source which concerns on embodiment. It is a sectional view of the luminous field of the surface emitting light source concerning a modification. It is the figure which showed the surface emitting light source which concerns on an Example and a reference example. FIG. 10 is a graph showing the luminance in the BB line cross section of FIG. 9; FIG. FIG. 10 is a graph showing luminance in a CC line section of FIG. 9; FIG. FIG. 10 is a graph showing the luminance in the BB line cross section of FIG. 9; FIG. FIG. 10 is a graph showing luminance in a CC line section of FIG. 9; FIG. FIG. 10 is a graph showing the luminance in the BB line cross section of FIG. 9; FIG. FIG. 10 is a graph showing luminance in a CC line section of FIG. 9; FIG.

Hereinafter, embodiments and examples for carrying out the present invention will be described with reference to the drawings. Note that the surface emitting light source described below is for embodying the technical idea of the present invention, and the present invention is not limited to the following unless there is a specific description.
In each drawing, members having the same function may be given the same reference numerals. In consideration of the explanation of the main points or the ease of understanding, the embodiments and examples may be divided for convenience, but the configurations shown in different embodiments and examples can be partially replaced or combined. In the embodiments and examples described later, descriptions of matters common to those described above will be omitted, and only differences will be described. In particular, similar actions and effects due to similar configurations will not be referred to successively for each embodiment or example. The sizes and positional relationships of members shown in each drawing may be exaggerated for clarity of explanation.

The surface-emitting light source according to this embodiment is a surface-emitting light source having a plurality of regions each including a light source and capable of being lit independently. Each light emitting region includes a light guide section that is adjacent to and included in the plurality of adjacent light emitting regions and covers the plurality of light sources, and a light reflecting member provided below the light guide section. . The light reflecting member has a first wall provided along the outer periphery of each light emitting region, and the first wall includes a plurality of unit first walls respectively corresponding to the light sources located on the outer periphery of each light emitting region. consists of The height of the unit first wall portion is lower at the central portion than at both end portions.

In the surface emitting light source according to the present embodiment, the wall is divided into unit wall portions in association with the light source located on the outer periphery of the light emitting region, and the distance to the light source provided on the outer periphery of the light emitting region is short. By lowering the central portion of the unit wall that strongly receives the light emitted from the light source than the both ends of the unit wall, the front light from the lighting area is reduced compared to the case where the wall is uniformly lowered. In addition, it is possible to suppress unevenness in brightness of light leaking from the lighting region to the adjacent light emitting region.

A surface emitting light source according to this embodiment and a method for manufacturing the surface emitting light source will be described below with reference to the drawings.

Embodiment <surface emitting light source>
As shown in FIG. 1, the surface emitting light source 20 according to the present embodiment includes a plurality of adjacent light emitting regions 1 arranged in a matrix of n rows×m columns on the wiring board 2 . The wiring substrate 2 is provided with a terminal 50 connected to a power supply and wiring for connecting the light emitting elements 34 provided in the light emitting region 1 . The surface-emitting light source 20 is powered by a power supply via the terminal 50 of the wiring board 2 and wiring, and lights up. The surface emitting light source 20 has a light emitting surface opposite to the surface on which the wiring board 2 is provided. A substrate having flexibility is preferably used for the wiring substrate 2 .
By arranging, for example, a diffusion sheet and a prism sheet on the light emitting surface side of the surface emitting light source 20, and by arranging, for example, an adhesive layer or non-adhesive layer and a back chassis on the wiring substrate 2 side, the backlight unit is configured.

The configuration of the light emitting region 1 included in the surface emitting light source 20 according to this embodiment will be described in detail below with reference to FIGS. 2 to 6D. In addition, in each figure, the code|symbol of the part which has the same structure may be abbreviate|omitted. In particular, in FIG. 2, to facilitate understanding of the drawing, reference numerals for the first wall portion, the unit first wall portion, the second wall portion, and the unit second wall portion are the third unit mounting area 1C, the fourth unit mounting area 1C, and the fourth unit mounting area 1C. Although the unit mounting area 1D, the fifth unit mounting area 1G, and the sixth unit mounting area 1H are assigned, the reference numerals for the walls of the other unit mounting areas can be similarly assigned.

<Emitting area>
As shown in FIG. 2, the light emitting region 1 according to the present embodiment includes first unit mounting regions 1A to sixteenth unit regions 1P arranged in a matrix of 4 rows×4 columns. Each of the first unit mounting area 1A to the sixteenth unit mounting area 1P has a rectangular top view shape. A light source 10 is arranged in the center of each unit mounting area. Therefore, each light emitting area contains 16 light sources 10 . The 16 light sources 10 included in each light emitting region are collectively controlled to turn on and off, and can be turned on independently for each light emitting region. As shown in FIGS. 2 and 3, each light emitting region further includes a light guide section 3 covering the 16 light sources 10 and a light reflecting member 11 provided on the lower surface 3b of the light guide section 3. As shown in FIGS. The light reflective member 11 includes a first wall portion 12 provided along the outer periphery of each light emitting area, and a second wall portion 14 located between the light sources 10 included in each unit mounting area. The first wall portion 12 is composed of a plurality of unit first wall portions 13, and as shown in FIG. 6A, the central portion 13h is lower than the both end portions 13e and 13f.
In the description of the surface emitting light source 20 of the present embodiment, one light emitting region having 16 unit mounting regions is taken as an example. The number is not limited to 16 and can be set to 1 or more.

<Light guide part>
As shown in FIGS. 2 and 3, the light guide section 3 is a thin plate-shaped member having an upper surface 3a and a lower surface 3b facing the upper surface 3a. The light guide part 3 is made of, for example, a thermoplastic resin such as acrylic, polycarbonate, cyclic polyolefin, polyethylene terephthalate, or polyester, a thermosetting resin such as epoxy or silicone, or glass.
In the surface emitting light source 20 according to this embodiment, the light guide portions 3 are members separated for each light emitting region 1, and the light guide portions 3 of the two adjacent light emitting regions 1 are arranged in contact with each other. However, the light guide portion 3 is not limited to this, and may be a light guide plate that collectively covers the plurality of light emitting regions 1, or collectively covers all the light emitting regions 1 included in the surface emitting light source 20. It may be composed of a single light guide plate for covering.

On the lower surface 3b of the light guide section 3, 16 first recesses 4 arranged in the central part of the unit mounting areas 1A to 1P are arranged along the outer periphery of the light emitting area 1, surrounding the 16 first recesses 4. A second recess 5 is provided to partition the 16 unit mounting regions 1A to 1P.

The fourth concave portion 7 is a concave portion for arranging the first wall portion 12 of the light reflecting member 11 . Therefore, the shape of the fourth concave portion 7 matches the shape of the first wall portion 12 of the light reflecting member 11, which will be described later.

The second concave portion 5 is a concave portion for arranging the second wall portion 14 of the light reflecting member 11 . Therefore, the shape of the second concave portion 5 matches the shape of the second wall portion 14 of the light reflecting member 11, which will be described later. The second recess 5 is provided along the side of each unit mounting area, straddling adjacent unit mounting areas, and communicates with the fourth recess 7 .

The 1st recessed part 4 is a recessed part for arrange|positioning the light source 10. As shown in FIG. As shown in FIG. 5, the first concave portion 4 is a rectangular parallelepiped concave portion including a rectangular opening 4a, a rectangular bottom surface 4b parallel to the bottom surface 3b of the light guide portion 3, and side surfaces 4c.

The upper surface 3 a of the light guide section 3 is provided with four third recesses 6 facing the first recesses 4 . The third recess 6 has a circular opening 6a, a circular flat bottom 6b, and side surfaces 6c. As shown in FIG. 5, the radius of the opening 6a is larger than the radius of the bottom 6b. That is, the third concave portion 6 has a tapered shape from the opening 6a side toward the bottom portion 6b side. Furthermore, in the top view shown in FIG. 2 , the outline of the opening 6 a of the third recess 6 surrounds the outline of the bottom surface 4 b of the first recess 4 . Also, the sum of the depth d2 of the third recess 6 and the depth d1 of the first recess 4 is smaller than the thickness t1 of the light guide portion 3, and the third recess 6 and the first recess 4 are not in communication.

A light reflecting layer 16 is arranged in the third recess 6 . By arranging the light reflecting layer 16 in the third recess 6 in this way, the light emitted directly above the light source 10 follows the outline of the third recess 6 whose opening 6a is wider than the bottom 6b. Widen the irradiation direction. As a result, the irradiation area of each light source 10 is widened, and uneven irradiation intensity is less likely to occur on the display illuminated by the light emitting area 1 . That is, the shape of the third concave portion 6, the light shielding property of the light reflecting layer 16, the thickness of the light guiding portion 3, and the like are set so that the irradiation intensity of the light emitted from the light emitting region 1 on the display is uniform.

The structure of the third recess is not limited to the above example, and the light guide section 3 may have a third recess having another shape. For example, as shown in FIG. 4, the third recess 6 includes, for example, a first portion 11a having a truncated cone shape and a second portion 11b having a truncated cone shape. The truncated cone-shaped bottom surface of the first portion 11a is in contact with the truncated cone-shaped upper surface of the second portion 11b. In the configuration illustrated in FIG. 4, both the first side surface 11c of the first portion 11a of the third recess 6 and the second side surface 11d of the second portion 11b of the third recess 6 are curvilinear in cross-sectional view. The light reflective layer 16 is positioned in the first portion 11 a of the third recess 6 that is closer to the light source 10 .

<Light source>
The light source 10 has a substantially rectangular parallelepiped external shape, and emits light mainly from the top surface. The light source 10 includes a light emitting element 34, a second light reflecting member 30, and a translucent member 31, as shown in FIG. The light emitting element 34 includes a semiconductor laminate 32 and a pair of electrodes 33 that supply power to the semiconductor laminate 32 . The second light reflecting member 30 is arranged to cover the side surface 34 c of the light emitting element 34 . The translucent member 31 is arranged to cover the upper surface 34 a of the light emitting element 34 and the upper surface of the second light reflecting member 30 . Therefore, the outer shape of the translucent member 31 when viewed from the top is larger than the outer shape of the light emitting element 34 when viewed from the top. Furthermore, a translucent adhesive member 35 may be provided between at least a portion of the side surface 34 c of the light emitting element 34 and the second light reflecting member 30 . By providing the translucent adhesive member 35, the light emitted from the side of the semiconductor laminate 32 enters the translucent adhesive member 35, and then the translucent adhesive member 35 and the second light-reflecting The light is reflected at the boundary with the member 30 and enters the translucent member 31 . As described above, the outer shape of the translucent member 31 when viewed from the top is larger than the outer shape of the light emitting element 34 when viewed from the top. By providing the optical adhesive member 35, the light emitted from the side of the semiconductor laminate 32 can be efficiently used. The light emitting element 34 is fixed to the lower surface side of the translucent member 31 with a translucent adhesive member 35 .
A wiring layer 60 is connected to each of the pair of electrodes 33 , and the electrodes 33 and the wiring of the wiring substrate 2 are connected via the wiring layer 60 . The wiring layer 60 extends between a light reflective member 11 and an insulating member 61 which will be described later.
In the light source 10 configured as described above, the translucent member 31 is accommodated in the first concave portion 4 and joined to the first concave portion 4 by the joining member 40 .

<Light emitting element>
As the light emitting element 34, a semiconductor light emitting element capable of emitting light having an arbitrary wavelength can be selected. For example, a light emitting diode or the like can be selected as the light emitting element 34 . As an example, the light emitting element 34 may be one that emits blue light. Without being limited to this, the light emitting element 34 may be one that emits light of a color other than blue light. When a plurality of light emitting elements 34 arranged at predetermined intervals are used in the surface emitting light source, those emitting light of the same color may be used, or those emitting light of different colors may be used.

For example, a _nitride -based semiconductor ( _{InxAlyGa1 -xyN} , 0≤X, 0≤Y, X+Y≤1) can be used as the semiconductor laminate of the light emitting element 34 capable of emitting blue light. can. In this case, the nitride-based semiconductor light-emitting device has, for example, a sapphire substrate and a nitride-based semiconductor laminated structure laminated on the sapphire substrate. The nitride-based semiconductor multilayer structure includes a light-emitting layer, and an n-type nitride-based semiconductor layer and a p-type nitride-based semiconductor layer positioned to sandwich the light-emitting layer. An n-side electrode and a p-side electrode, which are electrodes 33, are electrically connected to the n-type nitride semiconductor layer and the p-type nitride semiconductor layer, respectively.

The light emitting element 34 may have any shape in plan view, for example, a square shape, a rectangular shape, or the like. Furthermore, polygons such as triangles and hexagons may be used. In addition, the size of the light emitting element 34 in plan view can be, for example, 50 μm or more and 1000 μm or less, preferably 100 μm or more and 750 μm or less. The height of the light emitting element 34 may have a height of 50 μm to 500 μm, preferably 100 μm to 400 μm.

The translucent member 31 in the light source 10 has a substantially plate shape. The translucent member 31 may contain a wavelength conversion member. The wavelength conversion member absorbs at least part of the light emitted from the light emitting element 34 and emits light with a wavelength different from the wavelength of the light emitted from the light emitting element 34 . For example, the wavelength conversion member converts the wavelength of part of the blue light from the light emitting element 34 to emit yellow light. According to such a configuration, white light is obtained by mixing the blue light that has passed through the translucent member 31 and the yellow light emitted from the wavelength conversion member included in the translucent member 31 .

<Translucent member>
The material of the translucent member 31 includes silicone resin, modified silicone resin, epoxy resin, modified epoxy resin, urea resin, phenol resin, acrylic resin, urethane resin, fluorine resin, or two or more of these resins. Resin can be used. From the viewpoint of efficiently introducing light into the light guide section 3 , the material of the translucent member 31 preferably has a lower refractive index than the material of the light guide section 3 . A light diffusing function may be imparted to the translucent member 31 by dispersing materials having different refractive indices in the material of the translucent member 31 . For example, particles of titanium dioxide, silicon oxide, or the like may be dispersed in the material of the translucent member 31 .

The translucent member 31 may contain a wavelength conversion member. The wavelength conversion member absorbs at least part of the light emitted from the light emitting element 34 and emits light with a wavelength different from the wavelength of the light emitted from the light emitting element 34 . For example, the wavelength conversion member converts the wavelength of part of the blue light from the light emitting element 34 to emit yellow light. According to such a configuration, white light is obtained by mixing the blue light that has passed through the translucent member 31 and the yellow light emitted from the wavelength conversion member included in the translucent member 31 .

<Wavelength conversion member>
A phosphor can be used as the wavelength conversion member. A known material can be applied to the phosphor. Examples of phosphors include fluoride-based phosphors such as KSF-based phosphors, nitride-based phosphors such as CASN, YAG-based phosphors, and β-sialon phosphors. KSF-based phosphors and CASN are examples of wavelength-converting substances that convert blue light into red light, and YAG-based phosphors are examples of wavelength-converting substances that convert blue light into yellow light. β-sialon phosphor is an example of a wavelength conversion material that converts blue light to green light. The phosphor may be a quantum dot phosphor.

It is not essential that the phosphor contained in the translucent member 22 is common within a plurality of unit mounting regions contained in the same surface emitting light source. It is also possible to use different phosphors dispersed in the translucent member 31 among a plurality of unit mounting regions. A translucent member containing a wavelength conversion member that converts incident blue light into yellow light is arranged in some of the plurality of unit mounting regions, and some of the other unit mounting regions are arranged. , a translucent member containing a wavelength conversion member that converts incident blue light into green light may be arranged. Furthermore, a translucent member containing a wavelength conversion member that converts incident blue light into red light may be arranged in the remaining unit mounting area.

<Light reflective member>
As shown in FIG. 3, the light reflecting member 11 is provided on the lower surface 3b of the light guide section 3 and covers the lower surface 3b of the light guide section 3 and the side surface of the second light reflecting member 30 of the light source 10. ing. As a material of the light-reflecting member 11, for example, a resin material in which a light-reflecting filler is dispersed is used.

Silicone resin, phenol resin, epoxy resin, BT resin, polyphthalamide (PPA), or the like can be used as the base material of the resin material for forming the light reflecting member 11 . As the light-reflecting filler, metal particles or inorganic or organic material particles having a higher refractive index than the base material can be used. Examples of light-reflecting fillers are particles of titanium dioxide, silicon oxide, zirconium dioxide, potassium titanate, aluminum oxide, aluminum nitride, boron nitride, mullite, niobium oxide, barium sulfate, or particles such as yttrium oxide and gadolinium oxide. Examples include particles of various rare earth oxides. It is preferable that the light reflecting member 11 has a white color.

In the surface emitting light source 20 according to this embodiment, the light reflecting member 11 is provided for each light emitting region 1 . However, the light reflecting member 11 is not limited to this. For example, the light reflecting member 11 may be a member provided over a plurality of light emitting regions, or collectively cover all the light emitting regions included in the surface emitting light source 20. It may be one member. Further, the light reflecting member 11 according to the present embodiment is provided in contact with the lower surface 3 b of the light guide section 3 , but the light reflecting member 11 may be arranged below the light guide section 3 . For example, another member such as a bonding member or a translucent member or a space may be provided between the light reflecting member 11 and the light guide section 3 .
The lower surface of the light reflective member 11 is a flat surface, and the lower surface of the light reflective member 11 and the lower surface of the wiring layer 60 except for the area for connecting the wiring layer 60 and the wiring of the wiring board 2 are An insulating member 61 is arranged.

As shown in FIG. 2 , the light reflecting member 11 includes a first wall portion 12 arranged in the fourth concave portion 7 of the light guide portion 3 and a second wall portion 12 arranged in the second concave portion 5 of the light guide portion 3 . 2 walls 14 .

The first wall portion 12 is composed of unit first wall portions 13 provided according to the light sources located on the outer periphery of the light emitting region 1 . The unit first wall portion 13 is a wall portion that is arranged along the side located on the outer periphery of the light emitting region 1 among the sides of the unit mounting region where the light source is arranged.
In this embodiment, one light emitting region 1 includes 16 unit mounting regions 1A to 1P arranged in 4 rows×4 columns. Therefore, the unit first wall portion 13 is arranged along the side located on the outer periphery of the light emitting region 1 among the sides of the unit mounting regions 1A to 1E, 1H, 1I, 1L to 1P. Therefore, the first wall portion 12 in one light emitting region 1 is composed of 16 unit first wall portions 13 . The 16 unit first wall portions 13 are continuous and integrated to form the first wall portion 12 .

Next, the shape of the unit first wall portion 13 will be described in detail with reference to FIG. 6A.
The unit first wall portion 13 has a substantially right-angled triangular prism shape in which a part of the right-angled triangular prism is removed. Specifically, the unit first wall portion 13 has a substantially right triangular prism shape in which a concave portion is formed on the side facing one of the two orthogonal rectangular faces of the right triangular prism. The unit first wall portion 13 has a rectangular surface facing the side on which the recess is provided as a bottom surface 13b, and a surface formed by providing the recess (inner surface of the recess) as a top surface 13a. In addition, the unit first wall portion 13 has an extending direction of the right-angled triangular side surface as a lateral direction, and the concave portion extends from one end portion 13e to the other end portion 13f in the longitudinal direction of the unit first wall portion 13. It is set across.

The unit first wall portion 13 is arranged along one side of the unit mounting area in the longitudinal direction. Furthermore, the unit first wall portion 13 is arranged with the longitudinal side surface 13 d perpendicular to the bottom surface 13 b facing the outside of the light emitting region 1 . Therefore, in the surface emitting light source 20 in which a plurality of light emitting regions 1 are arranged in a matrix, the side surfaces 13d of the unit first wall portions 13 of two adjacent light emitting regions are in contact with each other.

The unit first wall portion 13 has a center portion 13h lower in height than both end portions 13e and 13f. Here, the central portion 13h is an area close to the light source 10 arranged in the central portion of the unit mounting area in which each unit first wall portion 13 is provided, and is strongly irradiated with the light emitted from the light source. area.

As described above, one of the purposes of varying the height of the unit first wall portion 13 is to prevent unevenness in the luminance of light leaking from the lit region to the adjacent unlit region. . In order to achieve this purpose, it is desirable that the surface of the unit first wall portion 13, particularly the vicinity of the upper surface 13a of the unit first wall portion 13, does not include corners or steps. This is because if corners or steps are provided on the surface of the unit first wall portion 13, these corners or steps may become obstacles to the progress of light, and may cause unevenness in the brightness of light leaking from the lighting region. It's for. Therefore, the height change from both end portions 13e and 13f of the unit first wall portion 13 to the central portion 13h is set smoothly, and the upper surface 13a of the unit first wall portion 13 is formed into a smooth surface.

Further, a curved surface 13g is provided between the upper surface 13a and the side surface 13c of the first unit wall portion 13 in order to make the vicinity of the upper surface 13a of the first unit wall portion 13 smooth.

As shown in FIG. 6A, the upper surface 13a of the unit first wall portion 13 according to the present embodiment is formed with a smooth curved surface. It may be formed by two smooth curved surfaces 113i and 113j continuing from the portions 113e and 113f and a plane 113k connecting the two smooth curved surfaces 113i and 113j and located in the central portion 113h. In addition, as shown in FIG. 6C, the upper surface of the unit first wall portion connects two planes 213i and 213j continuous from both ends 213e and 213f with two planes 213i and 213j, and a further plane located in the central portion 213h. It may be formed with the plane 213k. Moreover, as shown in FIG. 6D, the upper surface of the unit first wall portion may be formed by two flat surfaces 313i and 313j that are continuous from both end portions 313e and 313f and are connected to each other at a central portion 313h. In addition, regardless of the shape of the upper surface of the unit first wall, the height at the central portion is lower than the height at both ends, and curved surfaces are provided between the upper surface and the side surfaces. .

The first wall portion 12 composed of the unit first wall portion 13 having such a shape is arranged in the fourth recess portion 7 of the light guide portion 3, and the shape of the fourth recess portion 7 is the shape of the first wall portion 12. matches. Therefore, in the surface-emitting light source 20 in which a plurality of light-emitting regions 1 are arranged in a matrix, the fourth concave portions 7 of two adjacent light-emitting regions communicate with each other.

5 and 6A, the height of the unit first wall portion 13, the depth d1 of the first concave portion 4 of the light guide portion 3, the depth d2 of the third concave portion 6, and the light guide portion 3 and the thickness t1 will be described.
The height h1 of the central portion 13h of the unit first wall portion 13 is greater than the depth d1 of the first concave portion 4. As shown in FIG. Furthermore, the sum of the height h1 of the central portion 13h of the unit first wall portion 13 and the depth d2 of the third concave portion 6 is smaller than the thickness t1 of the light guide portion 3 . That is, the height h1 of the central portion 13h of the unit first wall portion 13 is the distance d3 from the lower surface 3b of the light guide portion 3 to the bottom portion 6b of the third recess 6 (=thickness t1 of the light guide portion 3−third smaller than the depth d2) of the recess 6; With such a configuration, the light emitted from the light source 10 can be spread within the light guide section 3 .
Moreover, the height h2 of both end portions 13e and 13f of the unit first wall portion 13 is less than half the thickness t1 of the light guide portion 3 and is more than twice the height h1 of the central portion 13h.

Next, the second wall portion 14 will be described.
The second wall portion 14 is composed of unit second wall portions 15 provided corresponding to the respective light sources 10, as shown in FIG. The unit second wall portion 15 is a wall portion arranged along a side of each of the unit mounting regions 1A to 1P on which the 16 light sources 10 are arranged, other than the side located on the outer periphery of the light emitting region 1. is. Therefore, in this embodiment, the second wall portion 14 is composed of 24 unit second wall portions 15 . The unit second wall portions 15 are continuously integrated with each other to form the second wall portion 14 . Furthermore, the second wall portion 14 and the first wall portion 12 may be continuously integrated.

Next, the shape of the unit second wall portion 15 will be described in detail with reference to FIG. 6A.
The shape of the unit second wall portion 15 is such that one unit first wall portion 13 indicated by a solid line in FIG. 6A and another unit first wall portion 13 indicated by a broken line in FIG. It is a shape integrated by contacting the side surface 13d orthogonal to 13b. This has the same shape as the two unit first wall portions 13 that contact the side surfaces 13d between the two adjacent light emitting regions.
The second wall portion 14 composed of the unit second wall portion 15 having such a shape is arranged in the second recess portion 5 of the light guide portion 3 , and the shape of the second recess portion 5 is the shape of the second wall portion 14 . Match the shape. Therefore, the shape of the second recess 5 is the same shape as the two fourth recesses 7 communicating between the two adjacent light emitting regions.

The shape of the unit second wall portion 15 is not limited to this, and may be a wall portion having a uniform height, for example. However, if the unit second wall portion 15 has a shape in which the two unit first wall portions 13 are integrated, the light emitting area 1 has the same configuration for each unit mounting area, and mass production is required. becomes easier.

The light emitting regions 1 configured as described above are arranged in a matrix of n rows×m columns and joined together to form the surface emitting light source 20 .

Method for Manufacturing Surface-Emitting Light Source Next, a method for manufacturing the surface-emitting light source according to this embodiment will be described.

<Process of preparing the light guide part>
First, as shown in FIG. 7A, a plurality of first recesses 4 arranged in a matrix, a fourth recess 7 surrounding the 16 first recesses 4 and arranged along the outer periphery of the light emitting region 1, A plurality of second recesses 5 that divide each unit mounting region in which the first recesses 4 are arranged in the light emitting region 1 are provided on the lower surface 103b and are arranged to face the plurality of first recesses 4, respectively. A light guide plate 103 having a top surface 103a provided with a third recess 6 is prepared. The fourth recess 7 can be formed integrally with the fourth recess 7 of the adjacent light emitting region.
Since the fourth recess 7 is a recess for disposing the first wall 12 , it is formed in the same shape as the first wall 12 . Moreover, as described above, the upper surface 13a of the unit first wall portion 13 may be formed of a smooth curved surface, a smooth curved surface and a flat surface, or a plurality of flat surfaces. Therefore, the shape of the fourth concave portion 7 , particularly the shape of the bottom surface of the fourth concave portion 7 , is appropriately changed according to the desired shape of the unit first wall portion 13 .
Also, the second recess 5 is a recess for arranging the second wall portion 14 . The unit second wall portion 15 according to the embodiment has the same shape as the two unit first wall portions 13 integrated. Therefore, the shape of the second concave portion 5 is the same shape as the shape in which the two fourth concave portions 7 of the adjacent light emitting regions are integrated. When the shape of the second recess 5 is the same as the shape of the integrated first recess 7 in this manner, the work of forming the recess is simplified, and mass production is facilitated.

Such a light guide plate 103 can be prepared by, for example, injection molding, transfer molding, thermal transfer, or the like. Also, the first concave portion 4, the second concave portion 5, the third concave portion 6, and the fourth concave portion 7 of the light guide plate 103 can be collectively formed with a mold when the light guide plate 103 is molded. As a result, misalignment during molding can be reduced. Alternatively, the light guide plate 103 may be prepared by preparing a plate without the first concave portion 4, the second concave portion 5, and the third concave portion 6 and processing the plate. Alternatively, the light guide plate 103 having the first concave portion 4, the second concave portion 5, the third concave portion 6 and the fourth concave portion 7 may be purchased and prepared.

<Step of Arranging Light Reflecting Layer>
Next, the light reflecting layer 16 is arranged in the third concave portion 6 . For the light reflecting layer 16, a light reflecting material such as a resin material in which a light reflecting filler is dispersed can be used. The light reflecting layer 16 can be formed by transfer molding, potting, printing, spraying, or the like. The step of arranging the light reflecting layer 16 may be performed after any step after the step of preparing the light guide section.

<Step of Placing Light Source in First Concave>
In this step, the light source 10 is placed on the bottom surface 4b of the first concave portion 4 so that the side surface 4c of the first concave portion 4 and the side surface of the light source 10 are at least opposed to each other. As shown in FIG. 7B, a liquid joining member 40 is placed on the bottom surface 4b of the first recess 4. As shown in FIG. The joining member 40 can be applied by a method such as potting, transfer, or printing. FIG. 7B illustrates a case where the joint member 40 is arranged by potting using the dispensing nozzle 84 . Also, the joining member 40 may be provided on the light source 10 side. For example, a method of picking up the light source 10 with an adsorption member such as an adsorption collet and dipping the light emitting surface of the light source 10 into the liquid bonding member 40 to attach the bonding member 40 may be used.

Next, as shown in FIG. 7C, the light source 10 is placed on the bonding member 40 inside the first recess 4 . At this time, the light source 10 is placed with the electrode 33 facing up. At this time, at least part of the side surface of the light source 10 faces the side surface 4 c of the first recess 4 . That is, the light source 10 is arranged so as to be partly embedded in the bonding member 40 . After that, the light source 10 and the light guide plate 103 are joined by curing the joining member 40 .

<Process of Arranging a Light Reflective Member Covering the Lower Surface of the Light Source and the Lower Surface of the Light Guide Plate>
Next, as shown in FIG. 7D, the light reflecting member 11 covering the lower surface 103b of the light guide plate 103 and the plurality of light sources 10 is formed. The light reflecting member 11 can be formed by transfer molding, potting, printing, spraying, or the like. FIG. 7D shows an example in which the dispensing nozzle 84 is used to form the light reflecting member 11 thick so as to cover the electrodes 33 of the light source 10 as well. The light reflecting member 11 may be formed so as not to bury the electrode 33, in other words, to expose at least a part of the electrode 33. FIG.

<Step of removing part of the light reflecting member>
Next, as shown in FIG. 7E, the entire surface of the light reflecting member 11 is removed. As a result, the electrodes 33 of the light source 10 are exposed from the light reflecting member 11, as shown in FIG. 7G. As a method of grinding, there is a method of grinding the light reflecting member 11 into a planar shape using a grinding member 90 such as a whetstone. Alternatively, as shown in FIG. 7F, a blast nozzle 91 may be used to eject hard particles 92 to partially remove the light reflecting member 11 .

Moreover, when the light source 10 has a wiring layer connected to the electrode 33, the light reflecting member 11 may be removed until the wiring layer is exposed. In either case, the light reflective member 11 is removed until a conductive member capable of powering the light source 10 is exposed. Also, if the light reflecting member 11 is formed so as not to bury the electrode 33 in advance, this step can be omitted.

<Step of forming a metal film electrically connected to a plurality of light sources>
Next, as shown in FIG. 7H, a wiring layer 60 is formed on substantially the entire surfaces of the electrodes 33 of the light source 10 and the light reflecting member 11 . The wiring layer 60 may have, for example, a laminated structure in which Cu/Ni/Au are laminated in this order from the light guide plate 103 side. The wiring layer 60 may be formed by sputtering, plating, or the like, and the wiring layer 60 is preferably formed by sputtering.

Next, as shown in FIG. 7I, the wiring layer 60 is irradiated with a laser beam 94 from a laser light source 93 and patterned by laser ablation to remove the irradiated portion of the wiring layer 60 . Thereby, the separated wiring layer 60 is formed. The wiring layer 60 is electrically connected to the electrodes 33 of the light source 10 .

<Step of Arranging Insulating Member>
Next, as shown in FIG. 7J, an insulating member 61 is arranged on the light reflecting member 11 and the wiring layer 60 . The insulating member 61 is arranged by a method such as printing, potting, or spraying. At this time, the insulating member 61 is arranged except for a region for connecting the wiring layer 60 and the wiring of the wiring board 2 .
Thus, the area aggregate 100A can be obtained.

<Step of Cutting Region Aggregate>
Next, along predetermined cutting positions CL shown in FIG. 7J, the area assembly 100A is divided into light emitting areas 1 each including 16 light sources.
Thus, a light-emitting module can be obtained.

<Process of Arranging Light-Emitting Module on Wiring Board>
Finally, the obtained light-emitting modules are arranged on the wiring board 2 and connected to the wiring of the wiring board 2 . A flexible substrate, for example, can be used for the wiring substrate 2 . The light sources arranged in each light emitting region 1 are wired so as to light up independently for each light emitting region. Alternatively, the 16 light sources included in one light emitting module may be wired so that they light up independently.

3. Other Embodiments Next, examples of surface emitting light sources according to other embodiments will be described with reference to FIGS. 8A to 8E.

The surface emitting light source 120 shown in FIG. 8A is different from that shown in FIG. is different from the surface emitting light source 20 shown in FIG.
The light source 110 included in the surface emitting light source 120 shown in FIG. 8A is composed of the light emitting element 34 and the translucent member 31 provided on the upper surface 34 a of the light emitting element 34 . Also in this case, the side surface 34c of the light emitting element 34 may be provided with the translucent adhesive member 35 that covers at least part of the side surface 34c.

Surface emitting light source 220 shown in FIG. 8B is different from surface emitting light source 20 shown in FIG. .

The translucent member 231 is desirably provided to cover the side surface of the semiconductor laminate 32 among the side surfaces 34 c of the light emitting element 34 . A region of the side surface 34 c of the light emitting element 34 that is not covered with the translucent member 231 is covered with the second light reflective member 230 . A light-transmitting member 231 and a portion of the light-emitting element 34 covered with the light-transmitting member 231 are accommodated in the first recess 4 of the light guide section 3 , and are positioned outside the first recess 4 of the light-emitting element 34 . The portion to be covered is covered with a light reflecting member 11 .

By providing the translucent member 231 on at least a part of the upper surface 34a and the side surface 34c of the light emitting element 34 in this manner, the light emitted from the light source 10 spreads into the light guide section 3 through the translucent member. be able to.

A surface emitting light source 320 shown in FIG. 8C has a translucent member 332 arranged on the upper surface 34a of the light emitting element 34, and a wavelength conversion member 331 arranged on the upper surface 3a of the light guide section 3. It differs from the light emitting source 20 .

The translucent member 332 is arranged to cover the upper surface 34 a of the light emitting element 34 and the upper surface of the second light reflecting member 30 . A translucent member 332 is accommodated in the first recess 4 of the light guide section 3 , and the side surface of the light source 310 located outside the first recess 4 is covered with the light reflecting member 11 . A translucent adhesive member 35 may be provided between at least a portion of the side surface 34 c of the light emitting element 34 and the second light reflecting member 30 .

Translucent member 332 does not contain a wavelength converting member. A light-diffusing function may be imparted to the translucent member 332 by dispersing a material having a refractive index different from that of the base material in the material of the translucent member 332 . For example, particles of titanium dioxide, silicon oxide, or the like may be dispersed in the base material of the translucent member 332 .

In the surface emitting light source 20 according to the mounting form shown in FIG. 5, one light emitting module constitutes one light emitting region, and a plurality of light emitting modules are arranged in a matrix of n rows×m columns. In the surface-emitting light source 420 shown in 8D, one light-emitting module constitutes a plurality of light-emitting regions 1 .

For example, as shown in FIG. 8D, the light emitting module 421 includes 16 light emitting regions 1 arranged in a matrix of 4 rows×4 columns, and the surface emitting light source 420 includes one or more light emitting modules 421 .

The light-emitting module 421 including a plurality of light-emitting regions 1 configured in this manner can control lighting for each unit mounting region by electrically connecting the light-emitting regions 1 in the light-emitting module 421 in parallel. .

A surface-emitting light source 520 shown in FIG. 8E is different from the surface-emitting light source 20 according to the embodiment in that the lower surface of the light reflecting member is not flat, but uneven over the entire lower surface. As shown in FIG. 8E, in the surface emitting light source 520 according to Modification 5, the lower surface of the light reflecting member 511 is positioned below the first wall portion 12 and the second wall portion 14 with the vicinity of the light source 10 as a convex portion. It is formed on a surface having a concave portion corresponding to the region where the contact point is formed. The lower surface of the light reflecting member 511 is a smooth surface from the convex portion to the concave portion.
The wiring layer 560 and the insulating member 561 are arranged along the uneven bottom surface shape of the light reflecting member 511 . Therefore, the lower surface of the insulating member 561 is also formed to be a smooth surface with convex portions located below the light source 10 and concave portions located below the first wall portion 12 and the second wall portion 14 . there is

The surface emitting light source 20 shown in FIG. 5 includes a plurality of unit mounting areas for each light emitting area 1, but is not limited to this. For example, one light emitting region 1 may be configured to include one unit mounting region.

In the surface-emitting light source 20 in the embodiment, rectangular unit mounting areas are arranged, but the shape of the unit mounting area is not limited to a rectangle. The shape of the unit mounting area may be, for example, another polygonal shape or circular shape, depending on the application of the surface emitting light source.

Furthermore, in the surface-emitting light source 20 in the embodiment, the unit first wall portions whose center portion is lower than both end portions are arranged along all sides of each light emitting region. The arrangement is not limited to this. The unit first walls may be arranged only along a pair of opposing sides of each light emitting region.
This configuration is particularly effective for a surface emitting light source having a rectangular unit mounting area. In the case of a surface-emitting light source having a rectangular unit mounting area, the first wall extending in the lateral direction is farther from the light source than the first wall extending in the longitudinal direction, so the light is emitted from the light source. The intensity with which the emitted light irradiates the first wall portion extending in the lateral direction is weakened. Therefore, the amount of light leaking to the adjacent unlit region through the first wall extending in the lateral direction is small. Therefore, in the light-emitting area where the unit mounting area is rectangular, only the unit first wall portion constituting the first wall portion extending in the longitudinal direction may be lower at the central portion than at both end portions.

Further, in the surface emitting light source 20 in the embodiment, the plurality of light emitting regions 1 are joined to one wiring board 2, but a plurality of one wiring substrate to which the plurality of light emitting regions 1 are joined are arranged to form one liquid crystal display. It may be used as a backlight for the device. At this time, for example, a plurality of wiring boards can be mounted on a frame or the like and connected to an external power supply using a connector or the like.

Example 1.
A surface-emitting light source of Example 1 was produced as follows.

First, a light guide plate 103 having a thickness t1 of 0.74 mm was prepared, and a first recess 4, a second recess 5, a third recess 6 and a fourth recess 7 were formed using a mold. The depth d1 of the first recess 4 was set at 0.2 mm, and the depth d2 of the third recess 6 was set at 0.34 mm. The depth of the second concave portion 5 is appropriately set according to the height h1 of the center portion 13h and the height h2 of both end portions 13e and 13f of the first unit wall portion 13, which will be described later.
Next, the liquid bonding member 40 was placed in the first recess 4, and the light source 10 was placed thereon. Further, a part of the light source 10 was arranged so as to be embedded in the bonding member 40 , and the bonding member 40 was cured to bond the light source and the light guide plate 103 .
Next, after placing the light reflecting member 11 covering the lower surface 103 b of the light guide plate 103 and the plurality of light sources 10 , the entire surface of the light reflecting member 11 was removed to expose the electrodes 33 of the light sources 10 .
Next, a wiring layer 60 was formed on substantially the entire surfaces of the electrodes 33 of the light source 10 and the light reflecting member 11 .
Next, the wiring layer 60 was irradiated with a laser beam 94 from a laser light source 93 and patterned by laser ablation for removing the irradiated portion of the wiring layer 60 . Thus, wiring layers 60 separated from each other and electrically connected to the electrodes 33 of the light source 10 were formed.
Next, the light reflecting layer 16 was arranged in the third concave portion 6 .
Finally, the light guide plate 103 was divided into light emitting areas 1 containing 16 light sources. The light-emitting region 1 had a rectangular top view shape, and was formed to have a square shape with lengths of 24.3 mm and 21.5 mm in the vertical and horizontal directions of the rectangular top surface 3a.
The height h1 of the center portion 13h of the unit first wall portion 13 in this embodiment was set to 0.59 mm, and the height h2 of the both end portions 13e and 13f was set to 0.593 mm. The upper surface 13a of the unit first wall portion 13 is formed into a smooth curved surface extending between the end portions 13e and 13f.

As shown in FIG. 9, the light emitting regions 1 produced as described above were arranged in a matrix of 3 rows×3 columns to produce a surface emitting light source. A light-emitting region in the center of the surface-emitting light source was lit. At this time, the luminance of light leaking from the central light-emitting region (lighting region) to the adjacent light-emitting region (light-out region) was measured. 10A is a graph showing the luminance in the B1-B1 line section of FIG. 9, and FIG. 10B is a graph showing the luminance in the B2-B2 line section of FIG.

Reference example 1.
In the surface emitting light source of Example 1, the height of the first wall portion and the height of the second wall portion were not changed, and both walls were set to a uniform height. A surface emitting light source of Reference Example 1 was produced in the same manner as the surface emitting light source. Then, the central light-emitting region of the surface-emitting light source was turned on, and the luminance of light leaking from the central light-emitting region (lighting region) to the adjacent light-emitting region (light-off region) was measured. 11A is a graph showing the luminance in the B1-B1 line cross section of FIG. 9, and FIG. 11B is a graph showing the luminance in the B2-B2 line cross section of FIG.

Reference example 2.
A surface emitting light source of Reference Example 2 was produced in the same manner as the surface emitting light source of Example 1, except that the second wall portion was formed to have a uniform height in the surface emitting light source of Example 1. Then, the central light-emitting region of the surface-emitting light source was turned on, and the luminance of light leaking from the central light-emitting region (lighting region) to the adjacent light-emitting region (light-off region) was measured. 12A is a graph showing the luminance in the B1-B1 line cross section of FIG. 9, and FIG. 12B is a graph showing the luminance in the B2-B2 line cross section of FIG.

From the results of Example 1, Reference Example 1, and Reference Example 2, the luminance of leaked light when the surface emission light source according to Example 1 is turned on is as follows: It became clear that the luminance decreases more smoothly than the luminance of the leaked light when lit.

1 light-emitting regions 1A to 1P unit mounting region 2 wiring substrate 3 light guide portion 3a upper surface 3b lower surface 4 first recess 4a opening 4b bottom surface 4c side surface 5 second recess portion 6 third recess portion 6a opening 6b bottom portion 6c side surface 7 fourth recess portion 10, 110, 210, 310 light source 11, 511 light reflecting member 12 first wall 13 unit first wall 13a top surface 13b bottom surface 13c side surface 13d side surface 13e, 13f end portion 13g curved surface 13h center portion 14 second wall portion 15 unit number 2 wall portions 16 light reflecting layers 20, 120, 220, 320, 420, 520 surface emitting light sources 30, 230 second light reflecting members 31, 231 translucent member 32 semiconductor laminate 33 electrode 34 light emitting element 35 translucent Adhesive member 40 Joining member 50 Terminals 60, 560 Wiring layers 61, 561 Insulating member 84 Dispensing nozzle 90 Grinding member 91 Blast nozzle 92 Particle 93 Laser light source 94 Laser light 100A Region assembly 103 Light guide plate 331 Wavelength conversion member 332 Translucent member

Claims (8)

A surface-emitting light source having a plurality of light-emitting regions each including a light source and each of which can be independently lit,
each light emitting region is adjacent,
a light guide portion included in the plurality of adjacent light emitting regions and covering the plurality of light sources;
a light reflective member provided below the light guide;
with
The light reflective member has a first wall provided on the outer periphery of each light emitting region,
A third concave portion having an opening on the upper surface is provided on the upper surface of the light guide portion, and the third concave portion is provided corresponding to each of the light sources,
The third recess has a frustum-shaped first portion that tapers from the opening side toward a bottom portion located on the opposite side of the opening, and a frustum-shaped portion having a bottom surface of the first portion as an upper surface. and the normal direction of the first side surface of the first portion and the normal direction of the second side surface of the second portion at the portion where the bottom surface of the first portion and the top surface of the second portion contact A surface emitting light source that changes discontinuously. 2. The surface emitting light source according to claim 1, wherein said first side surface and said second side surface are curved surfaces convex toward said opening side. 3. The surface emitting light source according to claim 1, wherein a portion where the bottom surface of the first portion and the top surface of the second portion are in contact has a concave shape in a direction opposite to the opening side. Each of the plurality of light sources is arranged in a first concave portion provided on a lower surface facing the upper surface of the light guide section,
The first wall portion is composed of one or more unit first wall portions corresponding to the light sources located on the outer periphery of each light emitting region,
4. The surface emitting light source according to any one of claims 1 to 3, wherein the height of the central portion of the unit first wall portion is greater than the depth of the first concave portion. The first wall portion is composed of one or more unit first wall portions corresponding to the light sources located on the outer periphery of each light emitting region,
5. The surface emitting light source according to claim 1, wherein the sum of the height of the central portion of the unit first wall portion and the depth of the third recess is smaller than the thickness of the light guide portion. The first wall portion is composed of one or more unit first wall portions corresponding to the light sources located on the outer periphery of each light emitting region,
The height of the central portion of the unit first wall portion according to any one of claims 1 to 5, wherein the height is smaller than the distance from the lower surface facing the upper surface of the light guide portion to the bottom portion of the third concave portion. surface emitting light source. The first wall portion is composed of one or more unit first wall portions corresponding to the light sources located on the outer periphery of each light emitting region,
Each of the heights of both end portions of the unit first wall portion is less than half the thickness of the light guide portion and is twice or more the height of the center portion of the unit first wall portion. 7. The surface emitting light source according to any one of 6. The lower surface of the light reflective member is provided with a convex portion and a concave portion,
8. The surface emitting light source according to any one of claims 1 to 7, wherein a smooth surface is formed in which the normal direction continuously changes from the convex portion to the concave portion.

Images