JP7236630B2 - light emitting module - Google Patents

Description

The present invention relates to light emitting modules.

2. Description of the Related Art A light-emitting module in which a light-emitting element such as a light-emitting diode and a light guide plate are combined is widely used as a surface light source such as a backlight of a liquid crystal display. For example, Patent Literature 1 discloses a configuration in which light sources are arranged in through holes by bonding a light guide plate having a plurality of through holes to a substrate on which a plurality of light sources are mounted.

JP 2011-211085 A

An object of the present invention is to provide a light-emitting module in which a light-emitting device can be arranged with high positional accuracy with respect to a light guide plate.

According to one aspect of the present invention, a light-emitting module includes a first surface, a second surface opposite to the first surface, and a penetrating portion penetrating between the first surface and the second surface. a light guide plate having the and a light-reflecting member covering the lower surface of the first light-transmitting member; and the first light-reflecting member disposed on the upper surface of the first light-transmitting member; and a second light transmissive member provided on the light emitting device and between the light emitting device and the side wall of the through portion. The light emitting device is fixed to the light guide plate by the second light transmissive member. The upper surface of the second light transmissive member has a recess.

According to one aspect of the present invention, it is possible to provide a light-emitting module in which a light-emitting device can be arranged with high positional accuracy with respect to a light guide plate.

1 is a schematic cross-sectional view of a light emitting module of one embodiment; FIG. 1 is a schematic cross-sectional view of a light emitting module of one embodiment; FIG. It is a schematic cross section which shows the manufacturing method of the light emitting module of one Embodiment. It is a schematic cross section which shows the manufacturing method of the light emitting module of one Embodiment. It is a schematic cross section which shows the manufacturing method of the light emitting module of one Embodiment. It is a schematic cross section which shows the manufacturing method of the light emitting module of one Embodiment. It is a schematic cross section which shows the manufacturing method of the light emitting module of one Embodiment. It is a schematic cross section which shows the manufacturing method of the light emitting module of one Embodiment. It is a schematic cross section which shows the manufacturing method of the light emitting module of one Embodiment. It is a schematic cross section which shows the manufacturing method of the light emitting module of one Embodiment. It is a schematic cross section which shows the manufacturing method of the light emitting module of one Embodiment. It is a schematic perspective view which shows the manufacturing method of the light emitting module of one Embodiment. It is a schematic cross section which shows the manufacturing method of the light emitting module of one Embodiment. FIG. 4 is a schematic cross-sectional view of a light-emitting module of another embodiment; It is a schematic cross section which shows the manufacturing method of the light emitting module of other embodiment. It is a schematic cross section which shows the manufacturing method of the light emitting module of other embodiment. FIG. 10 is a schematic cross-sectional view of a light-emitting module according to still another embodiment; FIG. 10 is a schematic cross-sectional view of a light-emitting module according to still another embodiment; FIG. 10 is a schematic cross-sectional view of a light-emitting module according to still another embodiment; FIG. 10 is a schematic cross-sectional view of a light-emitting module according to still another embodiment; FIG. 10 is a schematic cross-sectional view of a light-emitting module according to still another embodiment; FIG. 10 is a schematic cross-sectional view of a light-emitting module according to still another embodiment; FIG. 10 is a schematic cross-sectional view of a light-emitting module according to still another embodiment; FIG. 10 is a schematic cross-sectional view of a light-emitting module according to still another embodiment; It is a schematic cross-sectional view of a light emitting device of still another embodiment. It is a schematic cross-sectional view of a light emitting device of still another embodiment. It is a schematic cross-sectional view of a light emitting device of still another embodiment. 1 is a schematic plan view of a light emitting module of one embodiment; FIG. 1 is an exploded perspective view showing the configuration of a liquid crystal display according to an embodiment; FIG.

Hereinafter, embodiments will be described with reference to the drawings. In addition, the same code|symbol is attached|subjected to the same element in each drawing.

FIG. 1 is a schematic cross-sectional view of a light-emitting module according to one embodiment of the invention. FIG. 1 shows a cross section cut at a position passing through the central axis of the penetrating portion 15 formed in the light guide plate 10 .

The light emitting module of the embodiment has a light guide plate 10, a light emitting device 20, and a light transmissive member 30. As shown in FIG.

The light guide plate 10 has transparency to the light emitted by the light emitting device 20 . As the material of the light guide plate 10, for example, acrylic, polycarbonate, cyclic polyolefin, thermoplastic resin such as polyethylene terephthalate or polyester, thermosetting resin such as epoxy or silicone, glass, or the like can be used. The thickness of the light guide plate 10 is preferably 100 μm to 1000 μm, and more preferably 200 μm to 800 μm.

The light guide plate 10 has a first surface 11 serving as a light emitting surface and a second surface 12 opposite to the first surface 11 . Furthermore, the light guide plate 10 has a penetrating portion 15 penetrating between the first surface 11 and the second surface 12 .

The light emitting device 20 has a light emitting element 21 and a phosphor layer 22 as a light transmissive member. The phosphor layer 22 is arranged on the upper surface of the light emitting element 21 . The phosphor layer 22 may be in contact with the upper surface of the light emitting element 21, or may be joined with an adhesive or the like. The light emitting element 21 has a semiconductor laminate. The semiconductor laminate includes, for example, In _x Al _y Ga _1-xy N (0≦x, 0≦y, x+y≦1) and can emit blue light.

The phosphor layer 22 has a base material and a phosphor dispersed in the base material. As the material of the base material of the phosphor layer 22, for example, silicone resin, epoxy resin, glass, or the like can be used. The phosphor is a wavelength conversion substance that is excited by the light emitted by the light emitting element 21 and emits light with a wavelength different from the wavelength of the light emitted by the light emitting element 21 . For example, the phosphor _may be an yttrium-aluminum-garnet-based phosphor (e.g., _Y3 (Al, Ga) _5O12 :Ce), a lutetium-aluminum-garnet-based phosphor (e.g. _{, Lu3} (Al, Ga) _5O12 ). :Ce), terbium-aluminum-garnet-based phosphors (eg, Tb ₃ (Al, Ga) ₅ O ₁₂ :Ce), β-sialon-based phosphors (eg, Si _6-z Al _z O _z N _8-z : Eu ( 0<z<4.2)), α-sialon-based phosphors (for example, Mz(Si,Al) ₁₂ (O,N) ₁₆ (where 0<z≦2, and M is Li, Mg, Ca, Y , and lanthanide elements excluding La and Ce), nitride phosphors such as nitrogen-containing calcium aluminosilicate (CASN or SCASN) phosphors (for example, (Sr, Ca) AlSiN ₃ :Eu), KSF phosphors (K ₂ SiF ₆ :Mn) or fluoride-based phosphors such as MGF-based phosphors (3.5MgO·0.5MgF ₂ ·GeO ₂ :Mn), silicate-based phosphors (for example, (Ba, Sr) ₂ SiO ₄ :Eu) , a chlorosilicate-based phosphor (for example, Ca ₈ Mg(SiO ₄ ) ₄ Cl ₂ :Eu), etc. The phosphor layer 22 may contain a plurality of types of phosphors. Multiple bodies may be stacked.

A second light reflecting member 24 is provided on the side surface of the light emitting element 21 . A pair of positive and negative element electrodes is provided on the opposite side of the upper surface of the light emitting element 21 . The device electrode may include an ohmic electrode that makes ohmic contact with the semiconductor layer, and a columnar electrode (post electrode 26) that is connected to the ohmic electrode. A conductive film 27 is provided on the lower surface of the post electrode 26 and the lower surface of the second light reflecting member 24 . Although the light-emitting element 21 including the post electrodes 26 will be described below, the post electrodes 26 can be omitted, in which case the post electrodes 26 can be replaced with the element electrodes.

The post electrodes 26 are connected to the conductive film 27 . The post electrode 26 is provided on the bottom surface of the light emitting element 21 , and the conductive film 27 extends from the post electrode 26 to a region outside the bottom surface (side surface) of the light emitting element 21 . The post electrode 26 and the conductive film 27 function as the electrode section 25 of the light emitting device 20 . Incidentally, the conductive film 27 may cover only the lower surface of the post electrode 26 . Furthermore, a light-emitting device without the conductive film 27 may be used.

The second light reflecting member 24 is provided between the conductive film 27 and the phosphor layer 22 on the side of the light emitting element 21 . The second light reflecting member 24 directly or indirectly covers the side surface of the light emitting element 21 . For example, an adhesive or the like for connecting the phosphor layer 22 and the light emitting element 21 may be arranged on the side surface of the light emitting element 21 . Then, the side surface of the light emitting element 21 may be covered with the second light reflecting member 24 through the adhesive. The second light reflecting member 24 is also provided between the pair of post electrodes 26 on the lower surface of the light emitting element 21 . That is, at least part of the lower surface of the semiconductor laminate of the light emitting element 21 is covered with the second light reflecting member 24 .

The light emitting device 20 is arranged on the second surface 12 side of the penetrating portion 15 of the light guide plate 10 . That is, the light emitting device 20 is arranged at a position closer to the second surface 12 than to the first surface 11 . The light emitting element 21 is located closer to the second surface 12 than the phosphor layer 22 is, and the phosphor layer 22 is located closer to the first surface 11 than the light emitting element 21 is.

A light transmissive member 30 is provided in the through portion 15 of the light guide plate 10 . The light-transmissive member 30 has transparency to the light emitted by the light-emitting device 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 difference in refractive index from the material of the light guide plate 10. . Alternatively, glass may be used as the material of the light transmissive member 30 .

The light-transmitting member 30 is provided on the light-emitting device 20 and between the side surface of the light-emitting device 20 and the side wall of the through portion 15 . The light emitting device 20 is fixed to the light guide plate 10 by a light transmissive member 30 . Air layers are provided between the side surface of the light emitting device 20 and the light transmissive member 30, between the side wall of the penetrating portion 15 and the light transmissive member 30, and between the upper surface of the light emitting device 20 and the light transmissive member 30. Do not form a space such as However, without being limited to this, the light transmissive member 30 may contain air.

A concave portion 31 can be provided on the upper surface of the light transmissive member 30 . The recess 31 can be a conical recess such as a cone or a pyramid, or a truncated recess such as a truncated cone or a truncated pyramid. Alternatively, the recess may be recessed into a shape capable of refracting light only in one direction in plan view, such as a triangular prism shape or a semi-cylindrical shape. The opening diameter of the concave portion 31 can be made equal to the opening diameter of the penetrating portion 15 . Alternatively, the opening diameter of the recess 31 can be smaller than the opening diameter of the through portion 15 . Further, the center of the concave portion 31 can coincide with the center of the through portion 15 in plan view. Furthermore, the center of the recess 31 can coincide with the center of the light emitting device 20 in plan view. Alternatively, depending on the position of the penetrating portion 15 , the center of the recess 31 may not match the center of the penetrating portion 15 or the center of the light emitting device 20 in plan view. In the example shown in FIG. 1, a concave portion 31 having a V-shaped cross section is provided. That is, an inclined surface that is inclined with respect to the first surface 11 is provided on the upper surface of the light transmissive member 30 . Reflection and refraction of light occur at the interface between the light-transmitting member 30 and the air on this inclined surface, so that concentration of luminance in the region directly above the light-emitting device 20 can be suppressed. Alternatively, the upper surface of the light transmissive member 30 may be provided with a curved surface or a convex portion to diffuse the light and improve the light extraction efficiency.

A first light reflecting member 23 is provided between the upper surface of the phosphor layer 22 , which is the upper surface of the light emitting device 20 , and the light transmissive member 30 . The first light reflecting member 23 is in contact with the top surface of the light emitting device 20 (the top surface of the phosphor layer 22 in this example) and directly covers the top surface of the light emitting device 20 . Note that the first light reflecting member 23 may be part of the light emitting device 20 .

A third light reflecting member 50 is provided around the light emitting device 20 arranged in the through portion 15 on the second surface 12 side of the light guide plate 10 . The third light reflective member 50 is provided on the side surface of the second light reflective member 24 and is not provided on at least part of the side surface of the phosphor layer 22 . A part or all of the side surface of the phosphor layer 22 is covered with a light transmissive member 30 . It is preferable that the entire side surface of the phosphor layer 22 is in contact with the light transmissive member 30 .

The second surface 12 of the light guide plate 10 has a flat surface parallel to the first surface 11 and a concave portion having the inclined surface 13 as an inner surface. A corner between the second surface 12 and the inclined surface 13 may have a curvature. Also, a straight portion may be included between the second surface 12 and the inclined surface 13 . A fourth light reflecting member 40 is provided on the second surface 12 and the inclined surface 13 (that is, the inner side surface of the recess). The inclined surface 13 of the second surface 12 is an inner side surface of a recess provided in the second surface 12 so as to surround the through hole in plan view. When the light guide plate 10 includes a plurality of through portions 15, the inclined surface 13 is, for example, the inner side surface of a recess disposed between the through portion 15 and the adjacent through portion 15, as shown in FIG. . When the light guide plate 10 has a plurality of penetrating portions 15 , the concave portions of the second surface 12 are arranged in a grid pattern, and one penetrating portion 15 is provided in a region surrounded by each grid. Note that the second surface 12 of the light guide plate 10 may not have the inclined surface 13 . That is, the second surface 12 may be a flat surface. Also, the second surface 12 may be only an inclined surface without being provided with a flat surface. That is, the penetrating portion 15 and the inclined surface 13 may be in contact with each other.

The first light-reflecting member 23, the second light-reflecting member 24, the third light-reflecting member 50, and the fourth light-reflecting member 40 are made of, for example, a white resin containing a light reflecting material (or a light scattering material). can do. The first light-reflecting member 23, the second light-reflecting member 24, the third light-reflecting member 50, and the fourth light-reflecting member 40 are made of, for example, TiO ₂ or SiO as a light reflecting material (or a light scattering material). ₂ , Al ₂ O ₃ , ZnO, and other fine particles of silicone resin or epoxy resin. For the first light reflecting member 23 and the fourth light reflecting member 40, a light reflecting metal, a dielectric film (dielectric sheet), or the like can be used. When used as the first light-reflecting member 23 and the fourth light-reflecting member 40, in addition to the resin sheet made of the above-described white resin, a resin sheet that is visually recognized as white by containing air bubbles may be used. can be done.

The first light reflecting member 23 reflects part of the light emitted directly above the light emitting device 20 downward or laterally, and transmits the other part. As a result, it is possible to prevent the area immediately above the light-emitting device 20 from becoming too bright compared to other areas on the light-emitting surface of the light-emitting module.

Light emitted downward from the phosphor and light emitted laterally and downward from the light emitting element 21 are reflected upward by the second light reflecting member 24 and the third light reflecting member 50, The brightness of light extracted from the first surface 11, which is a light emitting surface, can be improved.

Further, the light guided through the light guide plate 10 is reflected toward the first surface 11 by the fourth light reflective member 40 provided on the second surface 12 and the inclined surface 13 of the light guide plate 10, and the light is reflected toward the first surface 11. The brightness of the light extracted from the surface 11 can be improved.

The lower surface of the fourth light reflective member 40, the lower surface of the third light reflective member 50, and the lower surface of the conductive film 27 are arranged on the same plane, and the lower surface of the fourth light reflective member 40 and the third light reflective member are arranged on the same plane. A wiring 61 containing metal is provided on the lower surface of the member 50 and the lower surface of the conductive film 27 . The conductive film 27 is connected to the wiring 61 . The light-emitting module is mounted on the wiring board via the wiring 61 .

As shown in FIG. 2, one light guide plate 10 may be provided with a plurality of penetrating portions 15 and a plurality of light emitting devices 20 may be arranged. A light emitting device 20 is arranged in each through portion 15 , and each light emitting device 20 is fixed to the light guide plate 10 by a light transmissive member 30 . Such a configuration realizes a wide surface light source with little luminance unevenness.

Next, a method for manufacturing a light emitting module according to one embodiment will be described with reference to FIGS. 3A to 8B.

First, as shown in FIG. 3A, the light guide plate 10 is prepared. The light guide plate 10 has a first surface 11, a second surface 12 on the opposite side of the first surface 11, and a concave portion whose inner surface is an inclined surface 13 forming an obtuse angle between the second surface 12 and the second surface 12. It is This concave portion is formed in a lattice shape in a plan view. Such a light guide plate 10 can be prepared, for example, by purchasing a plate-like light-transmitting member or forming it by injection molding or the like, and forming a concave portion using a processing tool. Alternatively, a light guide plate having recesses may be purchased in advance, or a light guide plate having recesses formed by injection molding or the like may be prepared.

Next, as shown in FIG. 3B, the fourth light reflecting member 40 is formed on the second surface 12 of the light guide plate 10 (the flat surface and the inclined surface 13 that is the inner side surface of the recess). When the fourth light-reflecting member 40 is made of a white resin material, examples of the forming method include a method of forming a liquid or paste-like light-reflecting resin by printing, spraying, compression molding, transfer molding, etc., and curing the resin. . Alternatively, a separately molded light-reflecting sheet may be attached. When the fourth light reflecting member 40 is made of metal, it may be applied by attaching a metal foil, sputtering, vapor deposition, paste printing, or the like. When the fourth light-reflecting member 40 is a dielectric material, a dielectric sheet may be adhered or formed by sputtering.

After forming the fourth light-reflecting member 40, as shown in FIG. 4A, a plurality of through-holes extending between the first surface 11 and the second surface 12 such that the fourth light-reflecting member 40 also penetrates. A hole 15 ′ is formed in the light guide plate 10 . FIG. 8A is a perspective view of the light guide plate 10 in which a plurality of through holes 15' are formed, viewed from the first surface 11 side. FIG. 4A is a cross-sectional view taken along line IVA-IVA in FIG. 8A. In the example shown in FIG. 8A, the planar shape of the through hole 15' may be circular, or may be polygonal such as triangular or quadrangular. In the case of a rectangular shape, the corners may be curved or chamfered.

For example, the through holes 15' can be formed by mechanical processing such as drilling or punching. Alternatively, the through holes 15' may be formed by etching or laser. In the case of mechanical processing, as shown in FIG. 8B, the corners of the end of the through hole 15' may have roundness (curvature). Further, in the case of mechanical processing, unevenness may be formed on the inner wall of the through hole 15'.

After forming the through holes 15 ′, the second surface 12 side of the light guide plate 10 is attached to the sheet 100 as shown in FIG. 4B. In this example, the surface of the fourth light reflecting member 40 is attached to the sheet 100 . The opening of the through-hole 15 ′ on the second surface 12 side is closed with the sheet 100 . A portion of the sheet 100 forms the bottom surface of the through hole 15'.

The light emitting device 20 described above is placed in the through hole 15' as shown in FIG. 5A. Specifically, the conductive film 27 that constitutes the electrode portion 25 shown in FIG. 1 in the light emitting device 20 is attached onto the sheet 100 that closes the opening of the through hole 15 ′ on the second surface 12 side. A gap exists between the side surface of the light emitting device 20 and the side wall of the through hole 15'.

After arranging the light emitting device 20 in the through hole 15', a liquid resin 30' is supplied into the through hole 15' as shown in FIG. 5B. Methods for supplying the resin 30' include potting, spraying, dispensing, jet dispensing, and printing. The resin 30′ includes a fine particle light reflecting material such as TiO ₂ , SiO ₂ , Al ₂ O ₃ , ZnO, or the like.

Then, by a centrifugal method, the light reflecting material contained in the resin 30' is sedimented on the sheet 100 that closes the upper surface of the light emitting device 20 and the opening of the through hole 15' on the second surface 12 side. The light reflecting material that settles on the sheet 100 settles in a region below the phosphor layer 22 .

6A, the first light reflecting member 23 is formed on the upper surface of the phosphor layer 22 of the light emitting device 20 by the settling of the light reflecting material, and the second light reflecting member 23 is formed around the second surface 12 side of the light emitting device 20, as shown in FIG. 6A. 3. A light reflecting member 50 is formed.

After the light reflector is allowed to settle, the resin 30' is cured. For example, the resin 30' is thermally cured at a temperature of around 150.degree. The sheet 100 has heat resistance against the temperature at this time.

By curing the resin 30', the light-transmitting member 30 is formed on the light-emitting device 20 in the through-hole 15' and between the light-emitting device 20 and the side wall of the through-hole 15'. The light emitting device 20 is fixed to the light guide plate 10 .

The upper surface of the light-transmitting member 30 is pressed by, for example, a mold, and recesses 31 are formed in the upper surface of the light-transmitting member 30 as shown in FIG. 6B. Alternatively, the concave portion 31 can be formed by reducing the volume of the light transmissive member 30 by curing or by making the resin 30' creep up on the inner surface of the through hole 15' using surface tension.

After that, the light guide plate 10 to which the light emitting device 20 is fixed is separated from the sheet 100, and as shown in FIG. do. Wiring 61 shown in FIG. 1 is formed on the second surface 12 side so as to connect to the exposed conductive film 27 .

According to the embodiment, after forming the fourth light reflecting member 40 on the second surface 12, the through hole 15' is formed, and the light emitting device 20 is arranged in the through hole 15'. The portion 25 is not covered with the fourth light reflecting member 40 . Further, since the resin 30' is supplied into the through hole 15' after the electrode portion 25 of the light emitting device 20 is attached to the sheet 100, the electrode surface of the light emitting device 20 is not covered with the resin 30'. In this example, since the lower surface of the conductive film 27 is in contact with the sheet 100, it is not covered with the resin 30'. After curing the resin 30 ′, the electrode surface of the light emitting device 20 is exposed by peeling off the sheet 100 . Therefore, the step of removing the fourth light reflective member 40 and the resin 30' covering the electrode surface of the light emitting device 20 is not required, and the wiring 61 can be easily connected to the electrode surface.

By providing a conductive film 27 extending from the post electrode 26 provided on the lower surface of the light emitting element 21 to a region outside the lower surface of the light emitting element 21, the electrode portion 25 of the light emitting device 20 and the wiring 61 are connected. facilitating the wiring connection and making highly reliable wiring connection possible.

In particular, by bonding the light guide plate 10 in which the plurality of through holes 15' are formed to the structure in which the plurality of light emitting devices 20 are previously mounted on the wiring board, the light emitting devices 20 are arranged in the through holes 15'. In this case, high accuracy is required between the mounting positions of the plurality of light emitting devices 20 on the wiring board and the positions of the plurality of through holes 15 ′ in the light guide plate 10 .

In contrast, according to the embodiment, since the light guide plate 10 holds the light emitting device 20 instead of the wiring substrate, and the light guide plate 10 and the light emitting device 20 are integrally configured, the light guide plate 10 and the light emitting device 20 are positioned high relative to the light guide plate 10 . The light emitting device 20 can be arranged with precision. This suppresses luminance unevenness within the light emitting surface of the light guide plate 10 .

Also, by attaching a flexible wiring board to the wiring 61, for example, it is possible to reduce the thickness of the entire module including the wiring board. Such a light-emitting module is suitable for, for example, a direct type backlight of a liquid crystal display.

FIG. 9 is a schematic cross-sectional view of a light-emitting module according to another embodiment.

The fourth light-reflecting member 40 is not provided on the inclined surface 13 of the recess of the light guide plate 10 , and the inclined surface 13 of the recess is in the air layer 70 provided between the fourth light-reflecting member 40 and the inclined surface 13 . in contact with The refractive index of the material of the light guide plate 10 is higher than that of air. The refractive index here represents the refractive index for the light emitted by the light emitting device 20 . Therefore, the light guided through the light guide plate 10 can be totally reflected by the inclined surface 13 and directed toward the first surface 11, and the brightness of the light extracted from the first surface 11 can be improved.

In manufacturing the structure of FIG. 9, as shown in FIG. 10A, the second surface 12 of the light guide plate 10 having the inclined surface 13 formed by processing or the like is attached to the sheet-like fourth light reflecting member 40, A through hole 15' is formed in the light guide plate 10 so as to penetrate the fourth light reflecting member 40 as well. An air layer 70 is interposed between the inclined surface 13 and the fourth light reflecting member 40 . As the sheet-shaped fourth light reflective member 40, for example, white resin containing a light reflecting material (or light scattering material), a multilayer film of resin or ceramics, a dielectric multilayer film, metal, or the like can be used.

Then, as shown in FIG. 10B, the fourth light reflecting member 40 is attached to the sheet 100 . After that, the light emitting device 20 is arranged in the through hole 15', and the same steps as those described above are continued. Note that FIGS. 10A and 10B show cross sections passing through the centers of the plurality of through holes 15', like the schematic cross sections of other drawings.

Further, as shown in FIG. 11, a light transmissive resin 71 may be provided on the inclined surface 13 of the light guide plate 10 . A light transmissive resin 71 is provided between the inclined surface 13 and the fourth light reflecting member 40 . A material having a smaller refractive index than that of the light guide plate is suitable for the light transmissive resin 71 .

Further, the light guide plate 10 may be flat as shown in FIG. 12 without forming the inclined surface 13 on the light guide plate 10 .

In addition, unevenness may be formed on the first surface 11 of the light guide plate 10 for diffusing light or improving light extraction efficiency. For example, FIG. 13 shows an example in which a plurality of projections 16 are formed on the first surface 11 of the light guide plate 10 . The plurality of protrusions 16 are formed, for example, concentrically around the penetrating portion 15 . In addition, the convex part 16 may be dot-shaped.

For example, the height and width of the protrusions 16 on the outer peripheral side farther from the light emitting device 20 are greater than the height and width of the protrusions 16 on the inner peripheral side closer to the light emitting device 20 . Also, the density of the protrusions 16 on the outer peripheral side can be made higher than the density of the protrusions 16 on the inner peripheral side. A concave portion may be formed on the first surface 11 instead of the convex portion 16 .

Further, unevenness may be formed on the second surface 12 of the light guide plate 10 . For example, FIG. 14 shows an example in which a plurality of concave portions 17 are formed on the second surface 12 of the light guide plate 10 . The second surface 12 is not limited to the concave portion 17 and may have a convex portion. The concave-convex shape is not limited to having a curved surface in a cross-sectional view, and may be concavo-convex formed of continuous inclined surfaces.

As shown in FIG. 15, the wiring 61 may be formed on, for example, the side surface of the fourth light reflecting member 40 that constitutes the side surface of the light emitting module. When a plurality of light-emitting modules are arranged with their sides adjacent to each other, the wirings 61 formed on the side surfaces of adjacent light-emitting modules can be connected directly or via a conductive material.

As shown in FIG. 16 , a phosphor layer 122 may be provided on the second surface 12 of the light guide plate 10 around the light emitting device 20 . The light whose wavelength has been converted by the phosphor layer 122 can be diffused in the plane direction by the light guide plate 10, and color unevenness within the plane of the light guide plate 10 can be suppressed.

As shown in FIG. 17, a light reflecting member 72 may be provided on the upper surface of the light transmitting member 30, for example, on the concave portion 31 having a V-shaped cross section. The light reflecting member 72 reflects part of the light emitted by the light emitting device 20 and transmits the other part. As a result, it is possible to prevent the area immediately above the light-emitting device 20 from becoming too bright compared to other areas on the light-emitting surface of the light-emitting module. Further, since the light transmissive member 30 is provided between the first light reflecting member 23 and the light reflecting member 72, it is possible to prevent the vicinity directly above the light emitting device 20 from becoming darker than the surroundings.

FIG. 18 is a schematic cross-sectional view of a light-emitting module according to still another embodiment.

A fourth light reflecting member 140 is provided on the second surface 12 of the light guide plate 10 with an adhesive sheet 92 interposed therebetween. The adhesive sheet 92 can be made of acrylic resin, for example. For example, the fourth light reflecting member 140 can be made of polyethylene terephthalate, which is visually recognized as white by forming a large number of air bubbles. The thickness of the fourth light reflecting member 140 is preferably 35 μm or more and 350 μm or less.

The lower surface of the light reflecting member 140 is adhered to the wiring substrate 80 via the adhesive sheet 93 . The adhesive sheet 93 contains acrylic resin, for example. The wiring board 80 has an insulating base material 81 , a wiring layer 82 , and pads 83 connected to the wiring layer 82 .

The light emitting device 20 has a light emitting element 21 and a phosphor layer 22 covering the top surface and side surfaces of the light emitting element 21 . The light emitting device 20 is arranged in the through portion 15 . In the through portion 15 , a light transmissive member 30 is provided above the light emitting device 20 and between the side surface of the light emitting device 20 and the side wall of the through portion 15 .

A first light reflecting member 23 is provided between the upper surface of the phosphor layer 22 , which is the upper surface of the light emitting device 20 , and the light transmissive member 30 . The first light reflecting member 23 is in contact with the top surface of the light emitting device 20 (the top surface of the phosphor layer 22 in this example) and directly covers the top surface of the light emitting device 20 .

A light reflecting member 124 is provided on the lower surface of the light emitting element 21 and the lower surface of the phosphor layer 22 . A light reflecting member 150 is provided on the surface of the wiring board 80 around the light emitting device 20 in the penetrating portion 15 . The light reflecting member 124 and the light reflecting member 150 are, for example, silicone resin or epoxy resin containing fine particles such as TiO ₂ , SiO ₂ , Al ₂ O ₃ and ZnO as light reflecting materials.

The electrodes 26 of the light emitting element 21 are bonded to the pads 83 of the wiring substrate 80 via bonding members (for example, solder) 91 .

As the light source of the light-emitting module, instead of the light-emitting device using the light-transmitting member such as the phosphor layer 22 as described above, only the light-emitting element can be used. Further, as shown in FIG. 19A, a light emitting device including a light emitting element 21 and a first light reflecting member 23 can be used as the light emitting device. In this case, the first light reflecting member 23 is arranged on the upper surface of the light emitting element 21 .

As shown in FIG. 19B, the light-emitting device includes a light-emitting element 21, a light-transmitting member 29 covering the upper surface and side surfaces of the light-emitting element 21, and a light-reflecting member 29 covering the lower surface of the light-emitting element 21 and the lower surface of the light-transmitting member 29. A configuration including the member 124 may also be used. The light-transmitting member 29 can be a phosphor layer containing phosphor, or can be a layer without phosphor. The first light reflecting member 23 is arranged on the top surface of the light transmitting member 29 .

As shown in FIG. 19C, the light emitting device may have a configuration including a light emitting element 21, a phosphor layer 22, a light transmissive member 129 containing no phosphor, and a light reflecting member . The phosphor layer 22 covers the upper surface of the light emitting element 21 . The light emitting element 21 is adhered to the phosphor layer 22 via an adhesive member 28 . The light reflective member 24 covers the side surfaces and the bottom surface of the light emitting element 21 and the side surface of the phosphor layer 22 . The light transmissive member 129 is arranged on the upper surface of the phosphor layer 22 . The first light reflecting member 23 is arranged on the upper surface of the light transmitting member 129 .

If the light emitting device does not contain phosphor, a phosphor sheet may be provided on the first surface 11 of the light guide plate 10 .

FIG. 20 is a schematic plan view of the light emitting surface (the first surface 11 of the light guide plate 10) side of the light emitting module of the embodiment. In this plan view, the first surface 11 of the light guide plate 10 is formed in a square shape with four corners, and the light emitting device 20 is also formed in a square shape with four corners.

In a plan view, the rectangular light emitting device 20 is rotated, for example, by 45 degrees with respect to the rectangular shape of the first main surface 11 of the light guide plate 10 . It intersects with the side (or side). For example, when the light guide plate 10 is square, the corners of the light emitting device 20 are not positioned on the diagonal lines connecting the corners of the first surface 11 .

In the light-emitting device 20 which is rectangular in plan view, the side surfaces have a larger area than the corners, and the brightness of the light emitted from the side surfaces of the light-emitting device 20 is higher than the brightness of the light emitted in the diagonal direction of the light-emitting device 20. also tends to be higher.

Further, on the rectangular first surface 11 of the light guide plate 10 , the distance between the central portion where the light emitting device 20 is arranged and the corners of the first surface 11 is equal to the distance between the central portion and the side portions of the first surface 11 . It is longer than the distance between them, and the light tends to be difficult to spread to the four corners of the first surface 11 .

According to the embodiment shown in FIG. 20, the light emitting device 20 is arranged with respect to the light guide plate 10 so that the diagonal line connecting the corners of the first surface 11 and the side surface (side portion) of the light emitting device 20 intersect. By locating the side surface of the light emitting device 20 so as to face the corners of the first surface 11, the light emitted from the light emitting device 20 can be easily spread to the four corners of the first surface 11 of the light guide plate 10. However, the present invention is not limited to this, and the light guide plate 10 that is square in plan view and the light emitting device 20 that is square in plan view are used, and one side of the light guide plate 10 and one side of the light emitting device 20 are parallel. The light emitting device 20 may be arranged as shown.

FIG. 21 is an exploded perspective view showing the configuration of a liquid crystal display 1000 including the light emitting module 200 of the embodiment.

This liquid crystal display 1000 includes a liquid crystal panel 120, two lens sheets 110a and 110b, a diffusion sheet 110c, and a light emitting module 200 in order from the top.

The light-emitting module 200 has the configuration of FIGS. 1, 9, and 11 to 20 described above, or a combination thereof. Furthermore, the light-emitting module 200 includes a plurality of through-holes 15 and a plurality of light-emitting devices 20 arranged in the through-holes 15 .

The liquid crystal display 1000 is a so-called direct type liquid crystal display in which a light emitting module 200 functioning as a backlight is stacked below (on the back side of) a liquid crystal panel 120 . The liquid crystal display 1000 irradiates the liquid crystal panel 120 with light emitted from the light emitting module 200 . A diffusion sheet 110c is superimposed on the first surface 11, which is the light emitting surface of the light guide plate 10, so that luminance unevenness within the light emitting surface can be suppressed. The liquid crystal display 1000 may further include members such as a polarizing film and a color filter in addition to the above constituent members.

The embodiments of the present invention have been described above with reference to specific examples. However, the invention is not limited to these specific examples. Based on the above-described embodiment of the present invention, all forms that can be implemented by those skilled in the art by appropriately designing and changing are also included in the scope of the present invention as long as they include the gist of the present invention. In addition, within the scope of the idea of the present invention, those skilled in the art can conceive of various modifications and modifications, and it is understood that these modifications and modifications also belong to the scope of the present invention. .

DESCRIPTION OF SYMBOLS 10... Light-guide plate 11... 1st surface 12... 2nd surface 13... Inclined surface 15... Through part 15'... Through hole 20... Light-emitting device 21... Light-emitting element 22... Phosphor layer 23 First light reflective member 24 Second light reflective member 25 Electrode portion 26 Post electrode 27 Conductive film 30 Light transmissive member 31 Concave portion 40 Fourth light reflective Member 50 Third light reflecting member 61 Wiring 70 Air layer 100 Sheet 120 Liquid crystal panel 200 Light emitting module 1000 Liquid crystal display

Claims (13)

a light guide plate having a first surface, a second surface opposite to the first surface, and a penetrating portion penetrating between the first surface and the second surface;
A light emitting device disposed on the second surface side of the penetrating portion, comprising: a light emitting element; a first light transmissive member covering an upper surface and side surfaces of the light emitting element; a lower surface of the light emitting element; a light-emitting device comprising: a light-reflecting member covering a lower surface of a transmissive member; and a first light-reflecting member disposed on the upper surface of the first light-transmitting member;
a second light transmissive member provided above the light emitting device and between the light emitting device and a sidewall of the through portion in the through portion;
with
The light emitting device is fixed to the light guide plate by the second light transmissive member ,
The light emitting module , wherein the upper surface of the second light transmissive member has a recess . a light guide plate having a first surface, a second surface opposite to the first surface, and a penetrating portion penetrating between the first surface and the second surface;
A light emitting device disposed on the second surface side of the penetrating portion, comprising: a light emitting element; a first light transmissive member covering an upper surface and side surfaces of the light emitting element; a lower surface of the light emitting element; a light-emitting device comprising: a light-reflecting member covering a lower surface of a transmissive member; and a first light-reflecting member disposed on the upper surface of the first light-transmitting member;
a second light transmissive member provided above the light emitting device and between the light emitting device and a sidewall of the through portion in the through portion;
a member disposed on the upper surface of the second light transmissive member, reflecting part of the light emitted by the light emitting device and transmitting the other part;
with
A light emitting module, wherein the light emitting device is fixed to the light guide plate by the second light transmissive member. 3. The light emitting module according to claim 1, wherein said first light transmissive member contains a phosphor. 4. The light-emitting module according to claim 3 , wherein said phosphor includes a KSF-based phosphor. 5. The light-emitting module according to claim 3 , wherein said phosphor includes a β-sialon-based phosphor. 3. The light-emitting module according to claim 1, wherein said first light-transmitting member does not contain a phosphor. 7. The light emitting module according to claim 6 , comprising a phosphor sheet on said first surface of said light guide plate. The light emitting module according to any one of claims 1 to 7 , wherein said second surface of said light guide plate comprises a flat surface parallel to said first surface, and a recess having an inner surface with an inclined surface. The light emitting module according to any one of claims 1 to 7 , wherein said light guide plate is flat. The light-emitting module according to any one of claims 1 to 9 , further comprising a resin sheet that contains air bubbles and is visually recognized as white on the second surface of the light guide plate via an adhesive sheet. 11. The light-emitting module according to claim 10 , wherein the resin sheet is polyethylene terephthalate that contains air bubbles and is visually recognized as white. 12. The light emitting module according to claim 10 , wherein the resin sheet has a thickness of 35 [mu]m or more and 350 [mu]m or less. 2. The light-emitting module according to claim 1 , further comprising a member that reflects part of the light emitted by said light-emitting device and transmits another part of the light emitted by said light-emitting device in said concave portion of said upper surface of said second light-transmitting member.

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