JP7029091B2 - Luminous module - Google Patents

Description

The present disclosure relates to a planar light emitting module in which a plurality of light emitting elements are arranged on one surface of a light guide plate.

A light emitting module using a light emitting element such as a plurality of light emitting diodes on one surface of a light guide plate is widely used as a backlight of a liquid crystal display or various light sources such as a display. For example, in the light source device disclosed in Patent Document 1, a plurality of light emitting elements are arranged on one surface of a light guide plate.

Japanese Unexamined Patent Publication No. 10-82915

A light emitting module in which a plurality of light emitting elements are arranged at predetermined intervals on one surface of a light guide plate is required to be thinned to suppress uneven brightness. The present disclosure is to provide a light emitting module capable of suppressing luminance unevenness while reducing the thickness.

The light emitting module of the present disclosure has a translucent light guide plate having a first main surface as a light emitting surface that radiates light to the outside and a second main surface opposite to the first main surface, and a light guide plate. It is provided with a light emitting element which is arranged on the second main surface of the above and irradiates light toward the light guide plate. The light guide plate has an optical functional unit that is larger than the light emitting surface of the light emitting element on the optical axis of the light emitted from the light emitting element, which is the first main surface, and is on the first main surface side of the light guide plate. A light-shielding scattering layer is arranged on the optical axis of the light-emitting element, and the light-shielding scattering layer covers the optical functional portion in a plan view.

According to the present disclosure, it is possible to provide a light emitting module capable of suppressing luminance unevenness while reducing the thickness.

It is a block diagram which shows each structure of the liquid crystal display apparatus which concerns on embodiment. It is a schematic plan view of the light emitting module which concerns on embodiment. It is a partially enlarged schematic sectional view of the light emitting module which concerns on embodiment. It is an enlarged schematic plan view and the enlarged schematic sectional view which shows an example of the light guide plate which concerns on embodiment. It is an enlarged schematic cross-sectional view which shows an example of the manufacturing process of a light emitting element unit. It is an enlarged schematic cross-sectional view which shows an example of the manufacturing process of the light emitting module which concerns on embodiment. It is an enlarged schematic cross-sectional view which shows an example of the manufacturing process of the light emitting module which concerns on embodiment. It is an enlarged schematic cross-sectional view which shows an example of the manufacturing process of the light emitting module which concerns on embodiment. It is an enlarged schematic cross-sectional view which shows an example of the manufacturing process of the light emitting module which concerns on embodiment. It is an enlarged schematic cross-sectional view which shows an example of the manufacturing process of the light emitting module which concerns on embodiment. It is an enlarged schematic cross-sectional view which shows an example of the manufacturing process of the light emitting module which concerns on embodiment. It is an enlarged schematic cross-sectional view which shows an example of the manufacturing process of the light emitting module which concerns on embodiment. It is an enlarged schematic cross-sectional view which shows an example of the manufacturing process of the light emitting module which concerns on embodiment. It is an enlarged schematic cross-sectional view which shows an example of the manufacturing process of the light emitting module which concerns on embodiment. It is an enlarged schematic cross-sectional view of the light emitting module which concerns on other embodiment. It is a schematic plan view of the light emitting module which concerns on embodiment. It is a circuit diagram which shows the structure of the light emitting module which concerns on embodiment. It is a schematic plan view when the light emitting module which concerns on embodiment is used for the liquid crystal display apparatus. It is an enlarged schematic sectional view of the light emitting module which concerns on embodiment. It is a plan view, a vertical sectional view, a horizontal sectional view, and a bottom view which show an example of the light guide plate which concerns on embodiment. It is an enlarged schematic sectional view of the light emitting module which concerns on embodiment. It is a plan view, a vertical sectional view, a horizontal sectional view, and a bottom view which show an example of the light guide plate which concerns on embodiment. It is an enlarged schematic sectional view of the light emitting module which concerns on embodiment. It is a plan view, a vertical sectional view, a horizontal sectional view, and a bottom view which show an example of the light guide plate which concerns on embodiment. It is an enlarged schematic sectional view of the light emitting module which concerns on embodiment. It is a plan view, a vertical sectional view, a horizontal sectional view, and a bottom view which show an example of the light guide plate which concerns on embodiment. It is an enlarged schematic sectional view of the light emitting module which concerns on embodiment. It is an enlarged schematic sectional view of the light emitting module which concerns on embodiment. It is an enlarged schematic sectional view of the light emitting module which concerns on embodiment. It is a schematic cross-sectional view of the light emitting module which concerns on embodiment. It is a plan view, a vertical sectional view, a horizontal sectional view, and a bottom view which show an example of the light guide plate which concerns on embodiment. It is a schematic cross-sectional view of the light emitting module which concerns on embodiment. It is a plan view, a vertical sectional view, a horizontal sectional view, and a bottom view which show an example of the light guide plate which concerns on embodiment. FIG. 16A is an enlarged cross-sectional view of a main part of the light guide plate of the light emitting module shown in FIG. 16A. It is a schematic cross-sectional view of the light emitting module which concerns on embodiment.

Hereinafter, the present invention will be described in detail with reference to the drawings. In the following description, terms indicating a specific direction or position (for example, "upper", "lower", and other terms including those terms) are used as necessary, but the use of these terms is used. The purpose is to facilitate understanding of the invention with reference to the drawings, and the meaning of these terms does not limit the technical scope of the present invention. Further, the parts having the same reference numerals appearing in a plurality of drawings indicate the same or equivalent parts or members.
Further, the embodiments shown below exemplify a light emitting module for embodying the technical idea of the present invention, and do not limit the present invention to the following. In addition, the dimensions, materials, shapes, relative arrangements, etc. of the components described below are not intended to limit the scope of the present invention to the specific description, but are exemplified. It was intended. Further, the contents described in one embodiment and the embodiment can be applied to other embodiments and the embodiments. In addition, the size and positional relationship of the members shown in the drawings may be exaggerated in order to clarify the explanation.

(Liquid crystal display device 3000)
FIG. 1 is a configuration diagram showing each configuration of the liquid crystal display device 3000 according to the present embodiment. The liquid crystal display device 3000 shown in FIG. 1 includes a liquid crystal panel 120, two lens sheets 110a and 110b, a diffusion sheet 110c, and a light emitting module 100 in this order from the upper side. The liquid crystal display device 3000 according to the present embodiment is a so-called direct type liquid crystal display device in which the light emitting module 100 is arranged below the liquid crystal panel 120. The liquid crystal display device 3000 irradiates the liquid crystal panel 120 with the light emitted from the light emitting module 100. In addition to the above-mentioned constituent members, members such as a polarizing film, a color filter, and a DBEF may be further provided.

1. 1. Embodiment 1
(Light emitting module 100)
The configuration of the light emitting module of this embodiment is shown in FIGS. 2A to 2C.
FIG. 2A is a schematic plan view of the light emitting module 100 according to the present embodiment. FIG. 2B is a partially enlarged schematic cross-sectional view showing the light emitting module 100 according to the present embodiment. FIG. 2C is a partially enlarged schematic plan view and a partially enlarged schematic cross-sectional view showing an example of an optical function unit 2 of the light guide plate 1 according to the embodiment and a recess 1b in which the light guide plate 1 is provided with a wavelength conversion unit.

The light emitting module 100 includes a light guide plate 1, a plurality of light emitting elements 11 arranged on the light guide plate 1, and a light-shielding scattering layer 3 laminated on the surface of the light guide plate 1. Each light emitting element 11 is arranged in a matrix on the light guide plate 1. The light guide plate 1 of the light emitting module 100 includes a first main surface 1c which is a light emitting surface that radiates light to the outside, and a second main surface 1d opposite to the first main surface 1c. The light guide plate 1 is provided with a plurality of partition recesses 1e on the second main surface 1d, and the wavelength conversion unit 12 is arranged between the adjacent partition recesses 1e. The wavelength conversion unit 12 is provided in the recess 1b provided in the light guide plate 1 and is arranged between the light emitting element 11 and the light guide plate 1. The wavelength conversion unit 12 converts the light emitted from the light emitting element 11 into wavelength and incidents it on the light guide plate 1. One light emitting element 11 is arranged in each of the wavelength conversion units 12.

As shown in FIG. 3, the light emitting module 100 shown in FIG. 2B includes a light emitting element 11, a wavelength conversion unit 12 that covers the main light emitting surface 11c of the light emitting element 11, and a light reflecting member 16 that covers the side surface of the light emitting element 11. By forming the light emitting element unit 10 provided with the light emitting element unit 10 and joining the light emitting element unit 10 to the recess 1b of the light guide plate 1 as shown in FIG. 4, the wavelength conversion unit 12 and the light emitting unit 12 emit light at a fixed position of the light guide plate 1. The element 11 is arranged so that the light emitted from the light emitting element 11 is incident on the light guide plate 1 via the wavelength conversion unit 12. However, in the light emitting module, it is not always necessary to arrange the wavelength conversion unit and the light emitting element as the light emitting element unit in the light guide plate, and the concave portion formed in the light guide plate is filled with the wavelength conversion material to form the wavelength conversion unit. It is also possible to join a light emitting element to this wavelength conversion unit and arrange the wavelength conversion unit and the light emitting element at a fixed position of the light guide plate.

Further, in the light emitting module 100 shown in FIG. 2B, the optical function unit 2 is provided on the first main surface 1c side of the light guide plate 1, and the light-shielding scattering layer 3 is arranged at a position covering the optical function unit 2 in a plan view. .. The optical function unit 2 is arranged on the optical axis of the light emitting element 11, and the light-shielding scattering layer 3 is also arranged on the optical axis. It is radiated to the outside.

The light emitted from the light emitting element 11 is incident on the light guide plate 1 via the wavelength conversion unit 12. In the above light emitting module 100, the light emitted from the light emitting element 11 is incident on the light guide plate 1 via the wavelength conversion unit 12. In the present specification, the "light emitting surface of the light emitting element" means a surface on which the light of the light emitting element is incident on the light guide plate. The surface of the wavelength conversion unit (the surface of the light emitting element unit) is the light emitting surface of the light emitting element. The light emitting module does not specify the light emitted from the light emitting element in a structure that is incident on the light guide plate via the wavelength conversion unit. For example, the light emitting module can also incident the light of the light emitting element on the light guide plate through the light adjusting layer. In the light emitting module in which the light of the light emitting element is incident on the light guide plate via the light adjusting layer, the light emitting surface of the light emitting element becomes the surface of the light adjusting layer. The light adjustment layer can be any layer that controls the light of the light emitting element and is incident on the light guide plate, such as a layer that scatters the light of the light emitting element and is incident on the light guide plate. Further, in this case, by forming a light emitting element unit provided with an optical adjustment layer instead of the wavelength conversion unit and arranging the light emitting element unit on the light guide plate, the light of the light emitting element is transferred to the light guide plate via the light adjustment layer. Can be incident.

In the light emitting module according to the present disclosure, the light emitting element 11 is arranged on the second main surface 1d of the light guide plate 1, the optical functional unit 2 is arranged on the first main surface 1c, and light shielding is performed so as to cover the optical functional unit 2. The scattering layer 3 is laminated. The light emitting module 100 having this structure can suppress uneven brightness while reducing the thickness. The light emitting module 100 in which the optical function unit 2 and the light-shielding scattering layer 3 are arranged in multiple layers on the optical axis of the light emitting element 11 receives light incident on the light guide plate 1 from the light emitting surface 11a of the light emitting element 11 by the optical function unit 2. The light on the optical axis that diffuses from the optical axis and has passed through the light guide plate 1 and the optical function unit 2 is shielded by the light-shielding scattering layer 3, and the strong light emission on the optical axis of the light-emitting element 11 is shielded. By diffusing to the surroundings, uneven brightness can be effectively suppressed while making the whole thinner. Further, since the light-shielding scattering layer 3 is arranged so as to cover the optical function unit 2 arranged on the optical axis of the light-emitting element 11, the light emitted through the optical function unit 2 is shielded and diffused by the light-shielding scattering layer 3. , Brightness unevenness can be further reduced. Further, the light-shielding scattering layer 3 suppresses the luminance unevenness due to the positional deviation between the optical function unit 2 and the light-emitting element 11, so that the light-emitting module 100 with less luminance unevenness can be efficiently mass-produced while being made thinner.

In a direct-type liquid crystal display device, since the distance between the liquid crystal panel and the light emitting module is short, the uneven brightness of the light emitting module may affect the uneven brightness of the liquid crystal display device. Therefore, as a light emitting module of a direct type liquid crystal display device, a light emitting module having less uneven brightness is desired.

By adopting the configuration of the light emitting module 100 of the present embodiment, the thickness of the light emitting module 100 can be reduced to 5 mm or less, 3 mm or less, 1 mm or less, and the like.

Each member constituting the light emitting module 100 and the manufacturing method according to the present embodiment will be described in detail below.

(Light guide plate 1)
The light guide plate 1 is a translucent member to which light from the light emitting element 11 is incident and emits light in a planar manner.
The light guide plate 1 of the present embodiment includes a first main surface 1c as a light emitting surface and a second main surface 1d opposite to the first main surface 1c.
The light guide plate 1 has a plurality of light emitting elements 11 arranged on the second main surface 1d. In the light guide plate 1 shown in FIG. 2, the light emitting element unit 10 is arranged in the recess 1b provided on the second main surface 1d, whereby the distance between the light guide plate 1 and the light emitting element 11 can be shortened, and light emission can be achieved. The module 100 can be made thinner.
The size of the light guide plate 1 can be, for example, about 1 cm to 200 cm on a side, and is preferably about 3 cm to 30 cm. The thickness can be about 0.1 mm to 5 mm, preferably 0.5 mm to 3 mm.
The planar shape of the light guide plate 1 can be, for example, a substantially rectangular shape, a substantially circular shape, or the like.

As the material of the light guide plate 1, a thermoplastic resin such as acrylic, polycarbonate, cyclic polyolefin, polyethylene terephthalate and polyester, a resin material such as a thermosetting resin such as epoxy and silicone, and an optically transparent material such as glass are used. be able to. In particular, a thermoplastic resin material is preferable because it can be efficiently manufactured by injection molding. Of these, polycarbonate, which has high transparency and is inexpensive, is preferable. The light emitting module to which the wiring board is attached after mounting the light emitting element 11 on the light guide plate 1 is a thermoplastic and low heat resistant material such as polycarbonate because the process of applying a high temperature such as reflow solder can be omitted. Can also be used.
The light guide plate 1 can be molded by, for example, injection molding, transfer molding, thermal transfer, or the like. When the light guide plate 1 is provided with an optical function portion 2, a recess 1b, and a partition recess 1e, which will be described later, it is preferable that these are also collectively formed by a mold. As a result, it is possible to reduce the molding position deviation between the optical function portion 2, the recess 1b, and the partition recess 1e.

The light guide plate 1 of the present embodiment may be formed of a single layer, or may be formed by laminating a plurality of translucent layers. When a plurality of translucent layers are laminated, it is preferable to provide a layer having a different refractive index, for example, an air layer, between arbitrary layers. This makes it easier to diffuse the light, and it is possible to obtain a light emitting module with reduced luminance unevenness. Such a configuration can be realized, for example, by providing a spacer between any plurality of translucent layers to separate them and providing an air layer.
Further, a transparent layer is provided on the first main surface 1c of the light guide plate 1, and a layer having a different refractive index, for example, an air layer, is provided between the first main surface 1c of the light guide plate 1 and the transparent layer. It may be provided. This makes it easier to diffuse the light, and it is possible to obtain a liquid crystal display device with reduced luminance unevenness. Such a configuration can be realized, for example, by providing a spacer between an arbitrary light guide plate 1 and a translucent layer to separate them, and providing an air layer.

(Optical function unit 2)
The light guide plate 1 is provided with an optical function unit 2 on the first main surface 1c side.
The optical function unit 2 can have, for example, a function of spreading the light incident on the light guide plate 1 in the plane by the optical function unit 2. The optical functional unit 2 is provided, for example, with a material having a refractive index different from that of the light guide plate 1. Specifically, as shown in FIG. 2B, the optical function unit 2 can be configured by a recess 1a provided in the light guide plate 1. The optical functional unit 2 in this figure is provided with an inclined surface 1x on the inner peripheral surface of the concave portion 1a. The inclined surface 1x is inclined upward in the figure so as to approach the light emitting element 11 toward the center of the recess 1a. The optical function unit 2 shown in the cross-sectional view of FIG. 2B has an inclined surface 1x having a shape in which the inclination angle (α) gradually increases toward the central portion. By providing the optical functional unit 2 having such a shape, the light incident on the light guide plate 1 from the light emitting surface 11a of the light emitting element 11 can be more effectively spread in the surface direction of the light guide plate 1. Further, the optical function unit 2 is provided with a flat surface portion 1y at the bottom thereof. In the optical function unit 2, the flat surface portion 1y is arranged in the central portion of the recess 1a. The optical functional unit 2 having the flat surface portion 1y provided in the central portion of the concave portion 1a can reduce the adverse effect of providing the concave portion 1a to reduce the strength of the light guide plate 1. This is because the flat surface portion 1y provided in the central portion can increase the minimum thickness of the light guide plate 1. The optical functional unit 2 is preferably arranged on the optical axis of the light emitting element 11, and more preferably, the flat surface portion 1y provided on the optical functional unit 2 is arranged on the optical axis of the light emitting element 11. The optical function unit 2 having the flat surface portion 1y can reduce the luminance unevenness due to the relative positional deviation between the light emitting element 11 and the optical function unit 2 as compared with the optical function unit without the flat surface portion. This is because the flat surface portion 1y is arranged parallel to the light emitting surface 11a of the light emitting element 11 which is the light incident surface, and the luminance unevenness due to the relative positional deviation between the flat surface portion 1y and the light incident surface is reduced. However, although not shown, the optical function unit is provided with a flat surface portion at the bottom as a recess such as an inverted cone, an inverted quadrangular pyramid, or an inverted hexagonal pyramid provided on the first main surface side, or a flat surface. It is also possible to have a shape without a portion.

The optical function unit 2 reflects the light incident from the light emitting element 11 in the lateral direction of the light emitting element 11 at the interface between the light guide plate 1, a material having a different refractive index (for example, air), and the inclined surface 1x of the recess 1a. Things can be used. Further, for example, a light-reflecting material (for example, a reflective film such as metal or a white resin) may be provided in the recess 1a having the inclined surface 1x. The inclined surface 1x of the optical function unit 2 is a curved line in a cross-sectional view, but may be a straight line. The inclined surface 1x of the optical functional unit 2 shown in the cross-sectional views of FIGS. 2B and 2C is a curved line in which the inclination angle (α) is gradually increased toward the center of the recess 1a in the cross-sectional view. As straight lines with different α), the inclination angle (α) can be gradually increased toward the center.

As will be described later, the optical functional unit 2 is arranged at a position corresponding to each light emitting element 11, that is, at a position opposite to the light emitting element 11 arranged on the second main surface 1d side.

The size of the optical function unit 2 can be appropriately set. The optical function unit 2 shown in FIG. 2B has a circular opening having an outer shape larger than the outer shape of the wavelength conversion unit 12 which is the light emitting surface 11a of the light emitting element 11. The optical function unit 2 can more effectively reflect the light incident on the light guide plate 1 from the light emitting surface 11a of the light emitting element 11 into the inside of the light guide plate 1 and spread it in the surface direction of the light guide plate 1. In the light emitting module 100 in which the light emitted from the light emitting element 11 is incident on the light guide plate 1 via the wavelength conversion unit 12, light is incident on the light guide plate 1 in all directions from the wavelength conversion unit 12. The light emitted from the light guide plate 1 is totally reflected at the interface with the optical function unit 2 and efficiently spread in the surface direction of the light guide plate 1, but the incident light of the light guide plate 1 is partially totally reflected. It is reflected in the surface direction of the light guide plate 1, and a part of it is transmitted through the optical function unit 2 without being totally reflected at the interface with the optical function unit 2 and is radiated to the outside from the first main surface 1c of the light guide plate 1. In particular, the flat surface portion 1y provided in the central portion of the recess 1a has a smaller incident angle of light at the interface between the optical function portion 2 and the light guide plate 1 as compared with the inclined surface 1x, and the probability of total reflection is reduced. Then, the light emitted to the outside becomes stronger. The light transmitted through the optical function unit 2 and radiated to the outside from the first main surface 1c of the light guide plate 1 causes a decrease in luminance unevenness.

(Light-shielding scattering layer 3)
The light emitting module 100 is provided with an optical function unit 2 on the light guide plate 1 to spread the light from the light emitting element 11 laterally to increase the light emission intensity of the light radiated to the outside from the first main surface 1c of the light guide plate 1. Although it is averaged, this is preferable because it reduces uneven brightness. In the light emitting module 100, the distance between the light emitting elements 11 can be narrowed to reduce the uneven brightness. However, if the distance between the light emitting elements 11 is narrowed, the number of light emitting elements fixed to the light guide plate 1 increases, and the component cost and the manufacturing cost increase. Will be higher. The light emitting module 100 has a difficult problem of reducing uneven brightness while reducing the number of light emitting elements 11 to reduce the cost. Further, the light emitting module 100 in which a plurality of optical function units 2 are provided on the light guide plate 1 and the light emitting element 11 is arranged in each optical function unit 2 has a brightness due to a relative positional deviation between the optical function unit 2 and the light emitting element 11. Unevenness is also an issue. In the light emitting module 100 in which the light guide plate 1 is provided with the recess 1a to form the optical function unit 2, the light guide plate 1 becomes thin in the central portion of the optical function unit 2 and the strength is lowered. The structure in which the flat surface portion 1y is provided in the central portion of the concave portion of the optical function portion 2 can increase the strength of the central portion of the concave portion, and the flat surface portion 1y can reduce the luminance unevenness due to the relative positional deviation from the light emitting element 11. In the flat surface portion 1y of the optical function unit 2, the light transmittance of the light emitting element 11 becomes high, and the effect of suppressing luminance unevenness decreases.

Therefore, in the light emitting module of the present embodiment, by providing a light-shielding scattering layer 3 at a position covering the optical function unit 2, the light emitting element 11 transmitted through the optical function unit 2 while preventing the intensity of the light guide plate 1 from decreasing. By scattering the incident light and blocking it, the harmful effects of the optical function unit 2 are reduced and uneven brightness is suppressed. The light emitting module of the present embodiment has a unique structure in which the optical function unit 2 and the light-shielding scattering layer 3 are arranged in a laminated structure. Use as a light source.

The light-shielding scattering layer 3 is arranged on the first main surface 1c of the light guide plate 1 at a position covering the optical functional unit 2. The light-shielding scattering layer 3 diffuses the light transmitted through the optical function unit 2 to block light and alleviate the luminance concentration. Specifically, the light-shielding scattering layer 3 is a layer in which a pigment or a dye is added to a sheet material such as a translucent plastic or glass. The pigment or dye is preferably white, and the reflectance of light is increased to suppress the brightness unevenness of the light emitting module 100 due to the light-shielding scattering layer 3. The light-shielding scattering layer 3 does not absorb the transmitted light to block light, but scatters the transmitted light to block light. However, the pigment or dye of the light-shielding scattering layer 3 is a colored pigment such as red, orange, or yellow, and absorbs a part of the transmitted light to control the light-emitting color of the light-emitting module 100 to scatter and block light. You can also do it. In particular, in a light emitting module in which the light emitting element 11 is a blue light emitting diode, the blue light of the blue light emitting diode can be wavelength-converted and radiated to the outside by using a pigment or dye that absorbs blue in the light-shielding scattering layer 3. can.

The light-shielding scattering layer 3 is preferably a resin containing a white pigment or the like. The light-shielding scattering layer 3 can control the amount of light-shielding by the amount of pigment or dye added. The light-shielding scattering layer 3 is preferably a silicone resin to which titanium oxide is added as a white pigment. The light-shielding scattering layer 3 controls the transmittance of transmitted light by the amount of the white pigment added. The light-shielding scattering layer 3 can reduce the transmittance of transmitted light by increasing the amount of the white pigment added to the resin. The transmittance is the attenuation ratio of light transmitted linearly in the light-shielding scattering layer 3 in the thickness direction, and is the ratio of "light intensity transmitted in the light-shielding scattering layer 3 in the thickness direction / intensity of incident light". The light-shielding scattering layer 3 is preferably added with a white pigment of 60% by weight or less to set the transmittance to an optimum value. The light-shielding scattering layer 3 can adjust the transmittance by controlling the addition rate of pigments and dyes.

The light-shielding scattering layer 3 reflects the transmitted light, scatters it, and blocks light. The light-shielding scattering layer 3 covers the optical function unit 2 in a plan view. The optical function unit 2 provided on the first main surface 1c of the light guide plate 1 spreads the light incident from the wavelength conversion unit 12 in the surface direction of the light guide plate 1 to suppress luminance unevenness. As shown by the arrow B in FIG. 2B, the optical function unit 2 reflects 100% of the light totally reflected at the boundary with the light guide plate 1 and diffuses it in the surface direction of the light guide plate 1. Total internal reflection of light occurs when the incident angle (θ) exceeds the critical angle. Light whose incident angle (θ) is smaller than the critical angle is radiated to the outside without being totally reflected at the boundary between the optical function unit 2 and the light guide plate 1. The light indicated by the arrow A in FIG. 2B has a small incident angle (θ) and passes through the flat surface portion 1y of the optical function portion 2. The light-shielding scattering layer 3 blocks the transmitted light of the optical function unit 2 transmitted to the outside through the optical function unit 2 and suppresses the uneven brightness of the light emitting module 100.

In the light emitting module 100 of FIG. 2, the light-shielding scattering layer 3 is arranged at a fixed position via the translucent sheet 4. The translucent sheet 4 is laminated on the first main surface 1c of the light guide plate 1 and the light-shielding scattering layer 3 is arranged at a position covering the optical functional unit 2. The light-shielding scattering layer 3 is provided so as to be laminated on the translucent sheet 4. The translucent sheet 4 is a scattering sheet that scatters and transmits transmitted light. In the light emitting module 100 using the translucent sheet 4 as a scattering sheet, in addition to suppressing the luminance unevenness of the light emitting module 100 by the translucent sheet 4, the light-shielding scattering layer 3 can further suppress the luminance unevenness. However, the translucent sheet 4 can also be a highly translucent sheet to which a white pigment is not added. The translucent sheet 4 is a sheet in which a white pigment is mixed with a translucent resin sheet such as PET having a film thickness of preferably about 100 μm or more and 1000 μm or less, and more preferably 100 μm or more and 500 μm or less. Can be used. Inorganic white powder such as titanium oxide is suitable for the white pigment of the translucent sheet 4.

The light-shielding scattering layer 3 is preferably a layer obtained by adding a white pigment to a translucent resin such as a silicone resin. It is preferable that the light-shielding scattering layer 3 has a smaller transmittance of light transmitted in the thickness direction than the translucent sheet 4. This is because the translucent sheet 4 suppresses the uneven brightness of the entire surface of the light emitting module, while the light-shielding scattering layer 3 alleviates the concentration of brightness in the central portion in the vicinity of the light emitting element 11 and eliminates the uneven brightness. .. The transmittance by which the light-shielding scattering layer 3 blocks light transmitted in the thickness direction is preferably set in the range of 0.1 / 10 to 7/10, more preferably 0.3 / 10 to 5/10. Can be done. However, the transmittance of the light-shielding scattering layer 3 is adjusted to an optimum value in consideration of the thickness of the light guide plate 1, the area of the light emitting surface 11a of the light emitting element 11, the light emitting intensity of the light emitting element 11, the shape of the optical functional unit 2, and the like. can do.

The light-shielding scattering layer 3 is laminated on the surface of the translucent sheet 4 or is arranged at a position covering the optical functional unit 2 as an integral structure with the translucent sheet 4. The light-shielding scattering layer 3 laminated on the translucent sheet 4 preferably has a lower transmittance of transmitted light than the translucent sheet 4. The light-shielding scattering layer 3 blocks the incident light from the optical function unit 2 to locally block the light radiated to the outside by the light emitting module 100 to reduce the uneven brightness, whereas the light-shielding scattering layer 3 is a scattering sheet. This is because the optical sheet 4 scatters the light radiated from the entire surface of the light emitting module 100 to reduce the unevenness of brightness.

The light-shielding scattering layer 3 laminated on the translucent sheet 4 and arranged at a fixed position is the surface of the translucent sheet 4 and is joined to the surface facing the light guide plate 1. The light emitting module 100 can efficiently suppress luminance unevenness by transmitting the light transmitted through the optical function unit 2 to the light-shielding scattering layer 3 and further transmitting the light transmitted through the light-shielding scattering layer 3 to the translucent sheet 4. .. In particular, in the light emitting module 100 using the translucent sheet 4 as the scattering sheet, the light-shielding scattering layer 3 can be arranged on the surface facing the light guide plate 1 to effectively suppress the uneven luminance. However, the light-shielding scattering layer can also be laminated on the opposite side of the light-transmitting sheet facing the light guide plate. This light emitting module transmits the optical function unit and transmits the light transmitted through the translucent sheet to the light-shielding scattering layer. In the light emitting module 100 in which the light-shielding scattering layer 3 is laminated on the translucent sheet 4 of the scattering sheet, the light-shielding scattering layer 3 is arranged on the surface facing the light guide plate 1, so that the light-shielding scattering layer 3 is on the opposite side to the facing surface. Brightness unevenness can be suppressed more effectively than arranging in. This is because the light whose luminance unevenness is suppressed by the light-shielding scattering layer 3 is transmitted to the scattering sheet.

In the light emitting module 100, the light-shielding scattering layer 3 and the light-transmitting sheet 4 are integrated, and the light-shielding scattering layer 3 can be partially provided on the light-transmitting sheet 4. The translucent sheet 4 constitutes the light-shielding scattering layer 3 by adding a pigment or a dye to the region constituting the light-shielding scattering layer 3 on the transparent plastic sheet. As the plastic sheet of the translucent sheet 4, for example, a fluororesin film can be used, and the thickness can be preferably 50 μm or more and 500 μm or less. The translucent sheet 4 having the scattering sheet and the light-shielding scattering layer 3 as an integral structure changes the concentration and material of the pigment or dye between the region of the light-shielding scattering layer 3 and the region of the scattering sheet. Since the light-shielding scattering layer 3 preferably has a lower light transmittance than the scattering sheet, the amount of the pigment or dye added can be made larger than that of the scattering sheet region.

The light-shielding scattering layer 3 arranged at a fixed position on the translucent sheet 4 is arranged at a position covering the optical functional unit 2. The translucent sheet 4 is partially joined to the light guide plate 1 and arranged at a fixed position of the light guide plate 1. The light emitting module 100 in which the rectangular translucent sheet 4 is laminated on the first main surface 1c side of the rectangular light guide plate 1 has one side of the translucent sheet 4 joined to the light guide plate 1 to form the light guide plate 1. Can be placed in place. In this light emitting module 100, the translucent sheet 4 is held in a flat shape and laminated on the surface of the light guide plate 1 in a state where the heat shrinkage between the translucent sheet 4 and the light guide plate 1 is different due to a temperature change, and the light emitting module 100 is shielded from light. The scattering layer 3 can be arranged close to the position of the optical functional unit 2 of the light guide plate 1.

The size of the light-shielding scattering layer 3 can be appropriately set. In a plan view, the outer shape of the light-shielding scattering layer 3 is larger than the outer shape of the optical function unit 2, and is arranged so as to cover the entire surface of the optical function unit 2. The light-shielding scattering layer 3 scatters the light emitted from the optical function unit 2, blocks light, alleviates the luminance concentration, suppresses the luminance unevenness, and radiates it to the outside. In the light emitting module 100 in which the light emitting element 11 is arranged in a matrix on the second main surface 1d of the light guide plate 1, the brightness in the vicinity of the light emitting element 11 becomes high. The light emitted from the light emitting element 11 is transmitted from the wavelength conversion unit 12 to the optical function unit 2 and from the optical function unit 2 through the light-shielding scattering layer 3 to suppress luminance unevenness and is radiated to the outside. In the light guide plate 1 in which the optical function portion 2 is composed of the recess 1a, the central portion of the optical function portion 2 becomes thin. Further, in the recess 1a having the flat surface portion 1y in the central portion, the flat surface portion 1y can reduce adverse effects such as luminance unevenness due to the relative positional deviation between the optical function unit 2 and the light emitting element 11, but the flat surface portion 1y guides the recess 1a. The specific region of the optical plate 1 becomes thin, and the intensity of transmitted light in this region becomes strong, which causes uneven brightness. The light-shielding scattering layer 3 also scatters the transmitted light of the flat surface portion 1y, shields the light, reduces the luminance concentration, and more effectively suppresses the luminance unevenness due to the transmitted light. The transmitted light of the optical function unit 2 is incident on the light-shielding scattering layer 3 from various directions, but the light-shielding scattering layer 3 shields the light incident from various directions and scatters the light to reduce the intensity of the transmitted light. Suppresses uneven brightness.

(Recess 1b)
The light guide plate 1 may be provided with a recess 1b on the second main surface 1d side. The recess 1b may have any shape as long as it can be targeted at the mounting position of the light emitting element 11. Specifically, for example, it may be a concave portion, a convex portion, a groove or the like as shown in FIGS. 2B, 2C and 4A.
The size of the recess 1b in a plan view can be, for example, 0.05 mm to 10 mm, preferably 0.1 mm to 1 mm. The depth can be 0.05 mm to 4 mm, preferably 0.1 mm to 1 mm. The distance between the optical function unit 2 and the recess 1b can be appropriately set within a range in which the optical function unit 2 and the recess 1b are separated from each other.
The plan view shape of the recess 1b can be, for example, a substantially rectangular shape or a substantially circular shape, and can be selected depending on the arrangement pitch of the recess 1b and the like. When the arrangement pitch of the recesses 1b (the distance between the two closest recesses) is substantially uniform, a substantially circular or substantially square is preferable. Above all, by making it substantially circular, the light from the light emitting element 11 can be satisfactorily spread.

(Light emitting element unit 10)
The light emitting element unit 10 includes a light emitting element 11, a wavelength conversion unit 12 that covers the main light emitting surface 11c of the light emitting element 11, and a light reflecting member 16 that covers the side surface of the light emitting element 11.
In the light emitting element unit 10 of FIG. 3, the light emitting element 11 is bonded to the surface of the wavelength conversion unit 12, and the main light emitting surface 11c of the light emitting element 11 is covered with the wavelength conversion unit 12. The light emitting element 11 is bonded to the surface of the wavelength conversion unit 12 via the translucent adhesive member 17. In the light emitting element unit 10 of FIG. 3, the outer shape of the wavelength conversion unit 12 is larger than the outer shape of the light emitting element 11 in a plan view. The light emitting element unit 10 can transmit more light emitted from the main light emitting surface 11c of the light emitting element 11 to the wavelength conversion unit 12 and enter the light guide plate 1 to reduce color unevenness and luminance unevenness. Further, the light emitting element unit 10 covers the side surface of the light emitting element 11 with a light reflecting member 16. In the light emitting element unit 10 shown in the figure, the outer surface of the light reflecting member 16 and the outer surface of the wavelength conversion unit 12 are substantially flush with each other.

(Wavelength converter 12)
The light emitting module 100 of the present embodiment may include a wavelength conversion unit 12 that diffuses the light from the light emitting element 11 and converts the wavelength of the light from the light emitting element 11.
As shown in FIG. 2B, the wavelength conversion unit 12 is provided between the light emitting element 11 and the light guide plate 1, and is arranged on the second main surface 1d side of the light guide plate 1. The wavelength conversion unit 12 internally diffuses and equalizes the light emitted from the light emitting element 11. In the light emitting module 100 shown in the figure, the light emitting element 11 and the wavelength conversion unit 12 are integrally formed as the light emitting element unit 10, so that the main light emitting surface 11c of the light emitting element 11 is covered with the wavelength conversion unit 12. The wavelength conversion unit 12 is preferably arranged in the recess 1b of the light guide plate 1 as shown in FIG. 2B for the purpose of reducing the thickness of the light emitting module.

However, the wavelength conversion unit 12 can also be arranged on the second main surface 201d of the flat light guide plate 201 as in the light emitting module 200 shown in FIG. The light emitting module 200 shown in the figure is formed between the light guide plate 201 and the light emitting element 11 by joining and fixing the wavelength conversion unit 12 of the light emitting element unit 10 on the second main surface 201d of the flat light guide plate 201. The wavelength conversion unit 12 is arranged. The light emitting element unit 10 is joined via, for example, a translucent adhesive member 17. In this way, the wavelength conversion unit 12 may be provided so as to project from the surface of the second main surface 201d.

Further, although not shown, the light emitting module may be formed by filling a recess formed in the light guide plate with a wavelength conversion material to form a wavelength conversion unit. It is preferable that the light emitting module includes a plurality of wavelength converters separated from each other. As a result, the wavelength conversion material can be reduced. Further, it is preferable that one wavelength conversion unit is provided for each light emitting element. As a result, it is possible to reduce luminance unevenness and color unevenness by making the light from the light emitting element uniform in the wavelength conversion unit.

The wavelength conversion unit formed by filling the concave portion with the wavelength conversion material can be formed by, for example, a method such as potting, printing, or spraying. When arranging the wavelength conversion material in the recess of the light guide plate to form the wavelength conversion unit, for example, after placing the liquid wavelength conversion material on the second main surface of the light guide plate, the inside of the plurality of recesses is squeezed or the like. By rubbing into, a wavelength conversion unit can be formed with good mass productivity.

Further, the wavelength conversion unit to be filled in the concave portion may be prepared in advance and the molded product may be arranged in the concave portion of the light guide plate or on the second main surface of the light guide plate. Examples of the method for forming the molded product of the wavelength conversion unit include a method of individualizing a plate-shaped or sheet-shaped wavelength conversion material by cutting, punching, or the like. Alternatively, a molded product of the wavelength conversion part of the small piece can be formed by a method such as injection molding, transfer molding, or compression molding using a mold or the like. The molded product of the wavelength conversion unit can be adhered to the inside of the recess or the second main surface of the light guide plate by using an adhesive or the like.

The size and shape of the wavelength conversion unit 12 can be, for example, about the same as the recess 1b described above. The height of the wavelength conversion unit 12 is preferably about the same as the depth of the recess 1b.

The first main surface 2c of the light guide plate 1 may have a process for causing light diffusion, reflection, or the like to a portion other than the optical functional unit 2. For example, by providing a fine unevenness or a rough surface in a portion separated from the optical function unit 2, it is possible to further diffuse light and reduce luminance unevenness.

The wavelength conversion unit 12 can use, for example, an epoxy resin, a silicone resin, a resin in which these are mixed, or a translucent material such as glass as the material of the base material. From the viewpoint of light resistance and moldability of the wavelength conversion unit 12, it is beneficial to select a silicone resin as the base material of the wavelength conversion unit 12. As the base material of the wavelength conversion unit 12, a material having a higher refractive index than the material of the light guide plate 1 is preferable.

Examples of the wavelength conversion member contained in the wavelength conversion unit 12 include a fluoride-based phosphor such as a YAG phosphor, a β-sialon phosphor, and a KSF-based phosphor. In particular, it is preferable to use a plurality of types of wavelength conversion members in one wavelength conversion unit 12, more preferably a β-sialon phosphor that emits green light and a KSF-based phosphor that emits red light. By including the fluoride-based phosphor of the above, the color reproduction range of the light emitting module can be expanded. Further, for example, 60% by weight of a KSF-based phosphor (red phosphor) is added to the wavelength conversion unit 12 so that red-based light can be obtained when the light emitting element 11 that emits blue-based light is used. As mentioned above, preferably 90% by weight or more may be contained. That is, the wavelength conversion unit 12 may include a wavelength conversion member that emits light of a specific color so that light of a specific color is emitted. Further, the wavelength conversion member may be a quantum dot.
The wavelength conversion member may be arranged in any way in the wavelength conversion unit 12. For example, it may be distributed substantially uniformly, or it may be unevenly distributed in a part. Further, a plurality of layers containing each wavelength conversion member may be laminated and provided.

For example, the wavelength conversion unit 12 may include fine particles such as SiO ₂ and TiO ₂ in the above-mentioned resin material to form a layer that scatters the light of the light emitting element 11.

(Light emitting element 11)
The light emitting element 11 is a light source of the light emitting module 100. The light guide plate 1 has a plurality of light emitting elements 11 arranged.

The light emitting element 11 has a main light emitting surface 11c that mainly extracts light, and an electrode forming surface 11d that is on the opposite side of the main light emitting surface 11c and has a pair of electrodes 11b. The pair of electrodes 11b are arranged to face the wiring board 20, and are optionally electrically connected to the board wiring of the wiring board 20 via the wiring 15 or the like.

The light emitting element 11 has, for example, a translucent substrate such as sapphire and a semiconductor laminated structure laminated on the translucent substrate. The semiconductor laminated structure includes a light emitting layer, an n-type semiconductor layer and a p-type semiconductor layer sandwiching the light emitting layer, and the n-side electrode and the p-side electrode are electrically connected to the n-type semiconductor layer and the p-type semiconductor layer, respectively. To. In the light emitting element 11, for example, the main light emitting surface 11c provided with the translucent substrate is arranged so as to face the light guide plate 1, and the light emitting element 11 has a pair of electrodes 11b on the electrode forming surface 11d opposite to the main light emitting surface 11c. The light emitting device 11 is a nitride semiconductor (In _x Aly Ga _{1-xy N} , 0 ≦ X, 0 ≦ Y, X + Y ≦) capable of emitting short wavelength light capable of efficiently exciting a wavelength conversion member. It is preferable to provide 1).

The light emitting element 11 is not particularly limited in vertical, horizontal and height dimensions. The light emitting device 11 preferably uses a semiconductor light emitting device having a vertical and horizontal dimension of 1000 μm or less in a plan view, more preferably a vertical and horizontal dimension of 500 μm or less, and further preferably a vertical and horizontal dimension of 200 μm. The following light emitting elements are used. When such a light emitting element is used, a high-definition image can be realized when the liquid crystal display device is locally dimmed. Further, if the light emitting element 11 having a vertical and horizontal dimension of 500 μm or less is used, the light emitting element 11 can be procured at low cost, so that the light emitting module 100 can be made cheap. In a light emitting element having both vertical and horizontal dimensions of 250 μm or less, the area of the upper surface of the light emitting element is small, so that the amount of light emitted from the side surface of the light emitting element is relatively large. That is, since such a light emitting element tends to emit light in a butt wing shape, the light emitting element 11 is bonded to the light guide plate 1, and the distance between the light emitting element 11 and the light guide plate 1 is very short. It is preferably used for.

Further, the light emitting module is provided with an optical function unit 2 having a reflecting or diffusing function such as a lens on the light guide plate 1, spreads the light from the light emitting element 11 laterally, and averages the light emitting intensity in the plane of the light guide plate 1. It is preferable to make it. However, in the structure in which the plurality of optical function units 2 are arranged at the positions corresponding to the plurality of light emitting elements 11 of the light guide plate 1, it may be difficult to position the small light emitting element 11 and the optical function unit 2.
Further, when the position of the light emitting element 11 or the optical function unit 2 is displaced, the relative position of the optical function unit 2 and the light emitting element 11 is displaced from the design, and the optical function unit 2 can sufficiently spread the light. However, there is a problem that the brightness becomes uneven due to the partial decrease in brightness in the plane.

Therefore, the light emitting module 100 in the present embodiment has a plurality of light emitting element units 10 on the light guide plate 1 with a plurality of positioning portions (particularly, recesses 1b) or optical function units 2 provided in advance in the light guide plate 1 as markers. By mounting, such positioning of the light emitting element 11 can be easily performed. As a result, the light from the light emitting element 11 can be made uniform with high accuracy, and a high-quality backlight light source with less luminance unevenness and color unevenness can be obtained.

Further, as described above, the light emitting element 11 can be positioned at a position corresponding to the optical function unit 2 on the surface opposite to the surface provided with the optical function unit 2, that is, overlapping with the optical function unit 2 in planar fluoroscopy. It is preferable to provide a positioning portion. Above all, by forming the concave portion 1b as the positioning portion and joining the wavelength conversion portion 12 of the light emitting element unit 10 to the concave portion 1b, the positioning of the light emitting element 11 and the optical function unit 2 can be performed more easily. ..
Further, in a structure in which the concave portion provided in the light guide plate is filled with a wavelength conversion material to provide a wavelength conversion unit and the light emitting element is bonded to the wavelength conversion unit, instead of arranging the light emitting element as a light emitting element unit in the concave portion. By forming a wavelength conversion unit that is different from the member of the light guide plate 1 and can be used for position recognition of the manufacturing apparatus inside the recess formed as the positioning unit, the light emitting element and the optical function unit can be connected to each other. Positioning can be performed more easily.

Further, the side surface of the light emitting element 11 is covered with the light reflecting member 16 to limit the direction of light emission, and the wavelength conversion unit 12 is arranged inside the recess 1b facing the main light emitting surface 11c of the light emitting element 11. By mainly extracting light from the wavelength conversion unit 12, the wavelength conversion unit 12 capable of diffusing light emission internally can be regarded as a light emitting unit. As a result, it is possible to further reduce the influence of the positional deviation of the light emitting element 11 that occurs within the range of the plan view, although it faces the wavelength conversion unit 12.

As the light emitting element 11, it is preferable to use a rectangular light emitting element in a plan view. Further, it is preferable that the upper surface shape of the light emitting element 11 is a rectangle having a long side and a short side. In the case of a high-definition liquid crystal display device, the number of light emitting elements 11 used is several thousand or more, and the mounting process of the light emitting elements 11 is an important process. Even if a rotational deviation (for example, a deviation in the ± 90 degree direction) occurs in some of the light emitting elements of the plurality of light emitting elements in the mounting process of the light emitting element 11, the rectangular light emitting element is used in a plan view to visually check the light emitting element. Confirmation is easy. Further, since the p-type electrode and the n-type electrode can be formed at a distance from each other, the wiring 15 described later can be easily formed.
On the other hand, when a square light emitting element is used in a plan view, a small light emitting element can be manufactured with good mass productivity.
Regarding the density (arrangement pitch) of the light emitting elements 11, the distance between the light emitting elements 11 can be, for example, about 0.05 mm to 20 mm, and is preferably about 1 mm to 10 mm.

The plurality of light emitting elements 11 are arranged in multiple stages in a plan view of the light guide plate 1. Preferably, the plurality of light emitting elements 11 are arranged at predetermined pitches along two orthogonal directions, that is, the x direction and the y direction, as shown in FIG. 2A. As shown in the example of FIG. 2A, the array pitch px in the x direction and the array pitch py in the y direction of the plurality of light emitting elements 11 may have the same pitch or differ between the x direction and the y direction. May be. The two directions of the array do not have to be orthogonal. Further, the arrangement pitches in the x-direction or the y-direction are not limited to equal intervals, and may be unequal intervals. For example, the light emitting elements 11 may be arranged so that the distance from the center of the light guide plate 1 becomes wider toward the periphery. The pitch between the light emitting elements 11 is the distance between the optical axes of the light emitting elements 11.

A known semiconductor light emitting device can be used as the light emitting device 11. In this embodiment, a light emitting diode is exemplified as the light emitting element 11. The light emitting element 11 emits blue light, for example. Further, as the light emitting element 11, a light source that emits white light may be used. Further, as the plurality of light emitting elements 11, light emitting elements that emit light of different colors may be used. For example, the light emitting module 100 may include a light emitting element that emits red, blue, and green light, and white light may be emitted by mixing red, blue, and green light.

As the light emitting element 11, an element that emits light having an arbitrary wavelength can be selected. For example, as an element that emits blue or green light, a nitride-based semiconductor (In _x Aly Ga _{1-xy N} , 0 ≦ X, 0 ≦ Y, X + Y ≦ 1) or a light emitting device using GaP is used. Can be used. Further, as the element that emits red light, a light emitting element containing a semiconductor such as GaAlAs or AlInGaP can be used. Further, a semiconductor light emitting device made of a material other than these can also be used. Various emission wavelengths can be selected depending on the material of the semiconductor layer and the mixed crystalliteity thereof. The composition, emission color, size, number, etc. of the light emitting element to be used may be appropriately selected according to the purpose.

(Translucent adhesive member 17)
The translucent adhesive member 17 joins the surface of the wavelength conversion unit 12 and the main light emitting surface 11c of the light emitting element 11. Further, as shown in FIG. 3, the translucent adhesive member 17 also covers a part of the side surface of the light emitting element 11 and a part of the wavelength conversion unit 12. The outer surface of the translucent adhesive member 17 is preferably an inclined surface extending from the side surface of the light emitting element 11 toward the wavelength conversion unit 12, and more preferably a curved surface convex toward the light emitting element 11. ..
Further, it is preferable that the translucent adhesive member 17 is arranged only in a range inside the outer edge of the wavelength conversion unit 12 in a plan view seen from the first main surface 1c side of the light guide plate 1. As a result, the light emitted from the side surface of the light emitting element 11 can be efficiently input by the wavelength conversion unit 12, so that the light extraction efficiency can be improved.
Further, a translucent adhesive member 17 may be provided between the main light emitting surface 11c of the light emitting element 11 and the wavelength conversion unit 12. As a result, for example, the light emitted from the main light emitting surface 11c of the light emitting element 11 by containing a diffuser or the like in the translucent adhesive member 17 is diffused by the translucent adhesive member 17 and enters the wavelength conversion unit 12. Can reduce uneven brightness.
As the translucent adhesive member 17, the same member as the translucent bonding member 14 described later can be used.

(Light reflective member 16)
Further, in the light emitting element unit 10, the side surface of the light emitting element 11 is covered with the light reflecting member 16 in a state where the wavelength conversion unit 12 is provided in the light emitting element 11. Specifically, the side surface of the light emitting element 11 not covered by the translucent adhesive member 17 and the outer surface of the translucent adhesive member 17 are covered with the light reflective member 16.
The light-reflecting member 16 is a material having excellent light-reflecting properties, and is preferably a white resin obtained by adding white powder or the like, which is an additive for reflecting light, to a transparent resin. The light emitting element unit 10 suppresses light leakage in directions other than the main light emitting surface 11c by covering the other surfaces of the light emitting element 11 other than the main light emitting surface 11c with the light reflecting member 16. That is, the light reflecting member 16 reflects the light emitted from the side surface of the light emitting element 11 and the electrode forming surface 11d, and effectively radiates the light emitted from the light emitting element 11 from the first main surface 1c of the light guide plate 1 to the outside. Therefore, the light extraction efficiency of the light emitting module 100 can be improved.

As the light reflecting member 16, a white resin having a reflectance of 60% or more with respect to the light emitted from the light emitting element 11 and preferably a reflectance of 90% or more is suitable. The light-reflecting member 16 is preferably a resin containing a white pigment such as white powder. In particular, a silicone resin containing an inorganic white powder such as titanium oxide is preferable.

The light reflecting member 16 is in contact with at least a part of the side surface of the light emitting element 11, and the light emitting element 11 is embedded around the light emitting element 11 to expose the electrode 11b of the light emitting element 11 to the surface. .. The light-reflecting member 16 is in contact with the wavelength conversion unit 12, and the outer surface of the light-reflecting member 16 and the outer surface of the wavelength conversion unit 12 are flush with each other. The light reflecting member 16 is arranged on the light guide plate 1 via a light emitting element unit 10 integrally bonded to the light emitting element 11 and the wavelength conversion unit 12.

(Translucent joint member 14)
The light emitting element unit 10 can be bonded to the light guide plate 1 by the translucent bonding member 14. In the present embodiment, the translucent joining member 14 is in contact with the inner surface of the recess 1b and the outer surface of the light emitting element unit 10. Further, the translucent joining member 14 is in contact with a part of the light reflecting member 16 located outside the recess 1b, in other words, from the outer surface of the wavelength conversion unit 12 to the outer surface of the light reflecting member 16. It is arranged so as to cover the straddling area. As a result, the light emitted in the side surface direction of the light emitting element unit 10 can be efficiently taken out into the translucent bonding member 14, and the light emitting efficiency of the light emitting module 100 can be improved. When the translucent joining member 14 covers the side surface of the light emitting element unit 10, it is preferable to form the transparent joining member 14 in a shape that expands in a cross-sectional view toward the light guide plate 1 as shown in FIG. 2B. Further, the outer surface of the translucent joining member 14 is an inclined surface, and the inclination angle formed with the outer surface of the light reflecting member 16 is an acute angle. As a result, the light emitted in the side surface direction of the light emitting element 11 can be efficiently taken out in the direction of the light guide plate 1.
Further, the translucent bonding member 14 may be arranged between the wavelength conversion unit 12 and the bottom surface of the recess 1b.

Further, as shown in FIG. 3, the translucent joining member 14 is in contact with the second main surface 1d of the light guide plate 1. As a result, the area where the inclined surface is formed is widened so that a large amount of light can be reflected and uneven brightness can be reduced.
Further, as shown in FIG. 3, the translucent joining member 14 has an inclined surface in a cross-sectional view. This shape can reflect the light transmitted through the translucent joining member 14 and incident on the inclined surface to the light emitting surface side in a uniform state.

As the translucent bonding member 14, a translucent thermosetting resin material such as an epoxy resin or a silicone resin can be used. Further, the translucent bonding member 14 has a light transmittance of 60% or more, preferably 90% or more. Further, the translucent joining member 14 may contain a diffusing material or the like, or may contain a white powder or the like which is an additive for reflecting light, or only a translucent resin material containing no diffusing material or the white powder or the like. It may be composed of.

When the light emitting element 11 includes a translucent substrate, the translucent bonding member 14 preferably covers at least a part of the side surface of the translucent substrate. As a result, among the light emitted from the light emitting layer, the light propagating in the translucent substrate and emitted in the lateral direction can be taken out upward. The translucent bonding member 14 preferably covers more than half of the side surface of the translucent substrate in the height direction, and is formed so as to be in contact with the side formed by the side surface of the light emitting element 11 and the electrode forming surface 11d. Is even more preferable.

(Sealing member 13)
The sealing member 13 seals the side surfaces of the plurality of light emitting element units 10, the second main surface 1d of the light guide plate 1, and the side surfaces of the translucent bonding member 14. Thereby, the light emitting element unit 10 and the light guide plate 1 can be reinforced. Further, by using the sealing member 13 as a light reflecting member, light emitted from the light emitting element 11 can be efficiently taken into the light guide plate 1. Further, the sealing member 13 also serves as a member for protecting the light emitting element unit 10 and a reflecting member provided on the surface opposite to the emission surface of the light guide plate 1, so that the light emitting module 100 can be made thinner. ..

The sealing member 13 is preferably a light-reflecting member.
The sealing member 13 of the light-reflecting member has a reflectance of 60% or more, preferably 90% or more, with respect to the light emitted from the light emitting element 11.
The material of the sealing member 13 of the light-reflecting member is preferably a resin containing a white pigment or the like. In particular, a silicone resin containing titanium oxide is preferable. As a result, the light emitting module 100 can be made inexpensive by using a large amount of inexpensive raw materials such as titanium oxide as a material used in a relatively large amount to cover one surface of the light guide plate 1.

(Wiring 15)
The light emitting module 100 may be provided with wiring 15 that is electrically connected to the electrodes 11b of the plurality of light emitting elements 11. The wiring 15 is the surface of the sealing member 13 and the like, and can be formed on the surface of the light guide plate 1 opposite to the first main surface 1c. By providing the wiring 15, for example, a plurality of light emitting elements 11 can be electrically connected to each other, and a circuit necessary for local dimming of the liquid crystal display device 3000 can be easily formed.
In the wiring 15, for example, as shown in FIGS. 4G to 4H, the positive and negative electrodes 11b of the light emitting element 11 are exposed on the surface of the sealing member 13, and the surface of the electrode 11b of the light emitting element 11 and the surface of the sealing member 13 are abbreviated. The wiring 15 can be formed by forming a metal film 15a on the entire surface and partially removing the metal film 15a with a laser or the like for patterning.

(Wiring board 20)
The light emitting module 100 of the present disclosure may have a wiring board 20 as shown in FIG. 4I. This makes it possible to easily form complicated wiring required for local dimming and the like. In this wiring board 20, after the light emitting element 11 is mounted on the light guide plate 1 and the sealing member 13 and the wiring 15 are arbitrarily formed, the wiring board 20 separately provided with the wiring layer 20b is attached to the electrodes 11b to 15 of the light emitting element. It can be formed by joining. Further, when the wiring 15 to be connected to the light emitting element 11 is provided, the wiring 15 has a shape larger than the planar shape of the electrode 11b of the light emitting element 11, so that the wiring board 20 and the light emitting element 11 or the like are electrically joined. Can be easily performed.

The wiring board 20 is a board including an insulating base material 20a, a wiring layer 20b electrically connected to a plurality of light emitting elements 11, and the like. The wiring board 20 is, for example, a wiring electrically connected to a conductive member 20c filled in a plurality of via holes provided in the insulating base material 20a and to the conductive member 20c on both side surfaces of the base material 20a. The layer 20b is formed.

Any material may be used for the wiring board 20. For example, ceramics and resins can be used. A resin may be selected as the material of the base material 20a from the viewpoint of low cost and ease of molding. Examples of the resin include composite materials such as phenol resin, epoxy resin, polyimide resin, BT resin, polyphthalamide (PPA), polyethylene terephthalate (PET), unsaturated polyester, and glass epoxy. Further, it may be a rigid substrate or a flexible substrate. In the light emitting module 100 of the present embodiment, since the positional relationship between the light emitting element 11 and the light guide plate 1 is predetermined, the material of the wiring board 20 is such that warpage occurs or stretches due to heat or the like. Even when a different material is used for the base material 20a, the problem of misalignment between the light emitting element 11 and the light guide plate 1 is unlikely to occur. Therefore, an inexpensive material such as glass epoxy or a thin substrate may be appropriately used. can.

The wiring layer 20b is, for example, a conductive foil (conductor layer) provided on the base material 20a, and is electrically connected to a plurality of light emitting elements 11. The material of the wiring layer 20b preferably has high thermal conductivity. Examples of such a material include a conductive material such as copper. Further, the wiring layer 20b can be formed by plating, coating with a conductive paste, printing, or the like, and the thickness of the wiring layer 20b is, for example, about 5 to 50 μm.

The wiring board 20 may be joined to the light guide plate 1 or the like by any method. For example, a sheet-shaped adhesive sheet can be bonded by arranging it between the surface of the sealing member 13 provided on the opposite side of the light guide plate 1 and the surface of the wiring board 20 and crimping them. Further, the wiring layer 20b of the wiring board 20 and the light emitting element 11 may be electrically connected by any method. For example, the conductive member 20c, which is a metal embedded in the via hole, can be melted by pressurization and heating and joined to the wiring 15.

The wiring board 20 may have a laminated structure. For example, as the wiring board 20, a metal plate having an insulating layer on its surface may be used. Further, the wiring board 20 may be a TFT board having a plurality of TFTs (Thin-Film Transistors).

(Manufacturing process of light emitting module 100)
Hereinafter, an example of the method for manufacturing the light emitting module of the present embodiment will be shown.
First, the light emitting element unit 10 is prepared. FIG. 3 shows an example of a manufacturing process of the light emitting element unit 10.
In the process shown in FIG. 3A, the wavelength conversion unit 12 that covers the main light emitting surface 11c of the light emitting element 11 is formed. In this step, the wavelength conversion unit 12 is formed on the surface of the base sheet 41 with a uniform thickness, and the base sheet 41 is arranged on the plate 42 so that it can be peeled off.

In the process shown in FIG. 3B, the light emitting element 11 is bonded to the wavelength conversion unit 12. The light emitting element 11 joins the main light emitting surface 11c side to the wavelength conversion unit 12. The light emitting element 11 is joined to the wavelength conversion unit 12 at a predetermined interval.
The light emitting element 11 is bonded to the wavelength conversion unit 12 via the translucent adhesive member 17. The translucent adhesive member 17 is applied on the wavelength conversion unit 12 and / or on the main light emitting surface 11c of the light emitting element 11 to join the light emitting element 11 and the wavelength conversion unit 12. At this time, as shown in FIG. 3B, the applied translucent adhesive member 17 crawls up to the side surface of the light emitting element 11, and the translucent adhesive member 17 covers a part of the side surface of the light emitting element 11. .. Further, the translucent adhesive member 17 may be arranged between the wavelength conversion unit 12 and the main light emitting surface 11c of the light emitting element 11.
As shown in FIG. 3E, the distance between the light emitting elements 11 is set to a dimension in which the outer shape of the wavelength conversion unit 12 becomes a predetermined size by cutting between the light emitting elements 11. This is because the distance between the light emitting elements 11 specifies the outer shape of the wavelength conversion unit 12.

In the step shown in FIG. 3C, the light reflecting member 16 is formed so as to embed the light emitting element 11. The light reflective member 16 is preferably a white resin. The light reflecting member 16 is arranged on the wavelength conversion unit 12 and is cured in a state where the light emitting element 11 is embedded. The light reflecting member 16 is arranged to have a thickness in which the light emitting element 11 is completely embedded, or in FIG. 3C, a thickness in which the electrode 11b of the light emitting element 11 is embedded. The light reflective member 16 can be molded by compression molding, transfer molding, coating or the like.

In the step shown in FIG. 3D, a part of the cured light-reflecting member 16 is removed to expose the electrode 11b of the light emitting element 11.

In the step shown in FIG. 3 (e), the light-reflecting member 16 and the wavelength conversion unit 12 are cut into individual pieces into a light emitting element unit 10. In the individualized light emitting element unit 10, the light emitting element 11 is bonded to the wavelength conversion unit 12, a light reflecting member 16 is provided around the light emitting element 11, and the electrode 11b is attached to the surface of the light reflecting member 16. It is exposed to.
As described above, regarding the preparation of the light emitting element unit, all the above-mentioned steps may be performed or a part of the steps may be performed. Alternatively, the light emitting element unit may be prepared by purchase.

The light emitting element unit 10 manufactured in the above steps is joined to the recess 1b of the light guide plate 1 in the steps shown in FIGS. 4A to 4C.

First, as shown in FIG. 4A, the light guide plate 1 is prepared. For the light guide plate 1, for example, polycarbonate is used as the material, the optical functional unit 2 of the recess 1a is provided on the first main surface 1c, and the wavelength conversion unit 12 of the light emitting element unit 10 is arranged at a fixed position on the second main surface 1d. In order to do so, a recess 1b having a substantially quadrangular opening and a partition recess 1e of the V groove are provided. The partition recesses 1e are linearly provided between the light emitting elements 11 arranged adjacent to each other. The partition recess 1e has a plurality of inclined surfaces continuous with the second main surface 1d. In a plan view, the optical functional unit 2 makes the light emitting element 11 larger than the light emitting surface 11a of the light emitting element incident on the light guide plate 1 and smaller than the region surrounded by the partition recess 1e provided in the light guide plate 1. In the light emitting module 100 of FIG. 2B, the light of the light emitting element 11 is incident on the light guide plate 1 via the wavelength conversion unit 12, so that the outer shape of the optical function unit 2 is the wavelength of the light emitting surface 11a of the light emitting element in a plan view. Make it larger than the conversion unit 12. The optical functional unit 2 is realized by a hollow recess 1a provided in the light guide plate 1, and an inclined surface 1x is provided on the inner peripheral surface of the recess 1a. The inclined surface 1x is inclined toward the center of the recess 1a in a direction approaching the light emitting element 11, and the inclination angle (α) is gradually increased toward the center. Is provided. The flat surface portion 1y is located in the central portion of the recess 1a constituting the optical function portion 2 and is a plane parallel to the light emitting surface 11a of the light emitting element. The light guide plate 1 in which the flat surface portion 1y is provided in the concave portion 1a of the optical function unit 2 can increase the strength of the light guide plate 1 by thickening the space between the thinnest recess 1a and the wavelength conversion unit 12. The optical function unit 2 arranges the flat surface unit 1y on the optical axis of the light emitting element 11. In the light guide plate 1, the center of the recess 1a of the optical function unit 2 and the center of the recess 1b of the wavelength conversion unit 12 are arranged on the optical axis of the light emitting element 11, and the recess 1a of the optical function unit 2 is centered on the wavelength conversion unit 12. That is, it can be arranged on the optical axis of the light emitting element 11. In a plan view, the outer shape of the optical function unit 2 is made smaller than the area surrounded by the partition recess 1e provided in the light guide plate 1, so that the light spread in the plane direction of the light guide plate 1 by the optical function unit 2 is upward. It can be taken out efficiently.

The light emitting element unit 10 is joined to the recess 1b of the light guide plate 1. As shown in FIG. 4B, the light emitting element unit 10 arranges a part of the light emitting element unit 10 in the recess 1b coated with the liquid translucent bonding member material 14a. Specifically, the wavelength conversion unit 12 of the light emitting element unit 10 is arranged so as to face the bottom surface of the recess 1b. Further, a part of the light reflecting member 16 is located outside the recess 1b.
The light emitting element unit 10 is arranged so that the center of the wavelength conversion unit 12 and the center of the recess 1b coincide with each other in a plan view, and the translucent bonding member 14 is cured and bonded to the light guide plate 1.

Here, in a plan view, the inner surface of the recess 1b is larger than the outer surface of the light emitting element unit 10, and when a part of the light emitting element unit 10 is arranged in the recess 1b, the inner surface of the recess 1b and the light emitting element unit 10 are arranged. A space is formed between the outer surface and the outer surface of the. This space is filled with the uncured translucent bonding member 14 applied to the recess 1b.

Further, by adjusting the coating amount of the material 14a of the translucent bonding member to be applied into the recess 1b, the space between the inner surface of the recess 1b and the outer surface of the light emitting element unit 10 is transparent to the outside of the recess 1b. The optical joining member 14 is extruded. As shown in FIGS. 4C and 2B, the translucent joining member 14 extruded from the recess 1b crawls up to a position where it comes into contact with a part of the light reflecting member 16 and covers a part of the light reflecting member 16. Further, in this state where the translucent joining member 14 extends to a position in contact with the second main surface 1d and covers a part of the second main surface 1d, the upper surface of the translucent joining member 14 is viewed in a vertical cross section. In, an inclined surface is formed from the upper end portion of the light emitting element unit 10 toward the outside. The inclined surface of the translucent joining member 14 has an acute angle formed between the inclined surface and the outer surface of the light reflecting member 16, preferably an inclined angle of 5 ° to 85 °, and more preferably 5 ° to 50 °. Is formed like this.

The amount of the material 14a of the translucent bonding member to be applied to the recess 1b is such that the translucent bonding member 14 covering the outer surface of the light emitting element unit 10 is a light guide plate in a state where the light emitting element unit 10 is bonded to the recess 1b. The amount may be higher than the second main surface 1d of 1, that is, the amount may be such that the concave portion 1b overflows to the outside.

Next, as shown in FIG. 4D, the material 13a of the sealing member is formed so as to embed the second main surface 1d of the light guide plate 1, the plurality of light emitting element units 10, and the plurality of translucent bonding members 14. The material 13a of the sealing member is a light-reflecting member in which titanium oxide and a silicone resin are mixed. The material 13a of the sealing member is formed by, for example, transfer molding, potting, printing, spraying, or the like. At this time, the material 13a of the sealing member is thickly formed so as to completely cover the upper surface (the surface opposite to the light guide plate 1) of the electrode 11b of the light emitting element 11. Next, as shown in FIG. 4E, a part of the material 13a of the sealing member is removed to expose the electrode 11b of the light emitting element 11 to form the sealing member 13. As a method for removing the material 13a of the sealing member, grinding with a grindstone, blasting, or the like can be used.

Next, as shown in FIG. 4F, a Cu / Ni / Au metal film 15a is formed from the light guide plate 1 side on substantially the entire surface of the electrode 11b of the light emitting element 11 and the sealing member 13 by sputtering or the like.

Next, as shown in FIG. 4G, the metal film 15a is patterned by laser ablation to form the wiring 15.

Next, as shown in FIG. 4H, the wiring 15 and the wiring layer 20b of the wiring board 20 prepared separately are pressure-bonded and joined with the adhesive sheet interposed therebetween. At this time, the wiring 15 and the wiring layer 20b are electrically connected by partially melting the conductive material filled in a part (for example, via) of the wiring layer 20b by pressurization and heating.

As shown in FIG. 4I, a light-shielding scattering layer 3 is provided at a position facing the optical functional unit 2 provided on the light guide plate 1. The light-shielding scattering layer 3 is bonded to the surface of the translucent sheet 4, the translucent sheet 4 is laminated on the light guide plate 1, and is arranged at a position covering the optical functional unit 2. The translucent sheet 4 has an outer shape substantially equal to the outer shape of the light guide plate 1, for example, the rectangular light guide plate 1 is laminated with the square translucent sheet 4 at a fixed position. A part of the outer peripheral edge of the translucent sheet 4 is joined to the light guide plate 1 and laminated at a fixed position of the light guide plate 1. In the rectangular translucent sheet 4, one side of the rectangular shape is joined to the light guide plate 1 and laminated at a fixed position of the light guide plate 1. The translucent sheet 4 in which a part of the outer peripheral edge is joined to the light guide plate 1 and laminated in a fixed position does not generate wrinkles due to thermal deformation due to a temperature change, and maintains a flat shape on the surface of the light guide plate 1. Can be placed. However, the translucent sheet 4 can be laminated at a fixed position of the light guide plate 1 by joining the entire outer peripheral edge or locally at a plurality of places to the light guide plate 1.

The translucent sheet 4 is preferably a scattering sheet in which a translucent resin sheet such as PET is mixed with a white powder such as titanium oxide powder as a white powder. The light emitting module 100 in which the light-shielding scattering layer 3 is arranged on the surface facing the optical function unit 2 of the light guide plate 1 via the scattering sheet preferably has the light-shielding scattering layer 3 with the light guide plate 1 as shown in FIG. 4I. Laminate on the facing surface. The light emitting module 100 scatters the light emitted from the light guide plate 1 by the light-shielding scattering layer 3 to block light, thereby alleviating the concentration of luminance in the central portion where the light-emitting element 11 is located, and further, the light-emitting module using a scattering sheet. This is because the light emission emitted from 100 to the outside can be equalized and the uneven brightness can be suppressed more effectively. The light-shielding scattering layer 3 is formed by mixing 60% by weight or less of titanium oxide powder with a silicone resin to increase the film thickness, preferably 10 μm or more and 100 μm or less, more preferably 10 μm or more and 50 μm or less, and optimally about. A layer having a thickness of 20 μm is preferable.

The light-shielding scattering layer 3 preferably has an outer shape larger than the outer shape of the optical functional unit 2 in a plan view. The light-shielding scattering layer 3 larger than the flat surface portion 1y of the optical function unit 2 scatters and shields the transmitted light of the optical function unit 2, alleviates the luminance concentration, and suppresses the luminance unevenness.

The plurality of light emitting elements 11 may be wired so as to be driven independently of each other. Further, the light guide plate 1 is divided into a plurality of ranges, and a plurality of light emitting elements 11 mounted in one range are grouped into one group, and the plurality of light emitting elements 11 in the one group are electrically connected in series or in parallel. It may be connected to the same circuit by being connected to the same circuit, and a plurality of such light emitting element groups may be provided. By performing such grouping, it is possible to obtain a light emitting module capable of local dimming.

Examples of such a light emitting device group are shown in FIGS. 6A and 6B. In this example, as shown in FIG. 6A, the light guide plate 1 is divided into 16 regions R of 4 columns × 4 rows. This one region R is provided with 16 light emitting elements arranged in 4 columns × 4 rows, respectively. The 16 light emitting elements 11 are assembled in a circuit of 4 parallels and 4 series as shown in FIG. 6B and electrically connected, for example.

One of the light emitting modules 100 of the present embodiment may be used as a backlight of one liquid crystal display device 3000. Further, a plurality of light emitting modules 100 may be arranged side by side and used as a backlight of one liquid crystal display device 3000. By making a plurality of small light emitting modules 100 and inspecting each of them, the yield can be improved as compared with the case of making a light emitting module 100 having a large number of light emitting elements 11 mounted large.

One light emitting module 100 may be bonded to one wiring board 20. Further, a plurality of light emitting modules 100 may be joined to one wiring board 20. As a result, the electrical connection terminals (for example, the connector 20e) to the outside can be integrated (that is, it is not necessary to prepare each light emitting module), so that the structure of the liquid crystal display device 3000 can be simplified.

Further, a plurality of wiring boards 20 to which the plurality of light emitting modules 100 are joined may be arranged side by side to form a backlight of one liquid crystal display device 3000. At this time, for example, a plurality of wiring boards 20 can be placed on a frame or the like and connected to an external power source by using a connector 20e or the like.

FIG. 6 shows an example of a liquid crystal display device including such a plurality of light emitting modules 100.
In this example, four wiring boards 20 having a connector 20e to which two light emitting modules 100 are joined are provided and mounted on a frame 30. That is, eight light emitting modules 100 are arranged in 2 rows × 4 columns. By doing so, it is possible to inexpensively manufacture a backlight for a large-area liquid crystal display device.

A translucent member having a function such as diffusion may be further laminated on the light guide plate 1. In that case, when the optical functional unit 2 is a dent, the opening of the dent (that is, the portion close to the first main surface 1c of the light guide plate 1) is closed, but a translucent member is used so as not to fill the dent. It is preferable to provide. As a result, an air layer can be provided in the recess of the optical function unit 2, and the light from the light emitting element 11 can be satisfactorily spread.

1-1. Modification 1 of Embodiment 1
FIG. 8A is an enlarged cross-sectional view of the light emitting module 300 according to the first modification. FIG. 8B shows a plan view, a vertical sectional view, a horizontal sectional view, and a bottom view of the light guide plate 1 used in the light emitting module 300, respectively. In these figures, the light-shielding scattering layer 303 arranged so as to cover the optical function unit 2 has an outer shape substantially equal to the outer shape of the optical function unit 2. The light emitting module 300 of the first modification has a concave portion 1a of the optical function portion 2 provided on the first main surface 1c in a truncated cone shape in which the inclination angle (α) of the inclined surface is gradually increased from the outer circumference toward the center. In the optical function unit 2 having this shape, the outer peripheral portion of the inclined surface 1x approaches the flat surface portion of the first main surface 1c of the light guide plate 1 without the optical function unit 2, and thus approaches the outer peripheral portion of the optical function unit 2. The brightness concentration can be alleviated accordingly. Therefore, it is possible to suppress the luminance unevenness while making the outer shapes of the optical function unit 2 and the light-shielding scattering layer 303 substantially the same.

1-2. Modification 2 of the first embodiment
FIG. 9A is an enlarged cross-sectional view of the light emitting module 400 according to the second modification. FIG. 9B shows a plan view, a vertical sectional view, a horizontal sectional view, and a bottom view of the light guide plate 1 used in the light emitting module 400, respectively. In the second modification, the outer shape of the light-shielding scattering layer 403 is larger than the flat surface portion 1y of the optical function unit 2 and smaller than the outer shape of the optical function unit 2. With such a shape, the luminance concentration of the light transmitted through the flat surface portion 1y of the optical function unit 2 is scattered by the light-shielding scattering layer 403, and the light is shielded, so that the luminance unevenness can be suppressed. Further, the flat surface portion 1y of the optical function unit 2 provides the flat surface portion 1y to the optical function unit 2 while eliminating the luminance unevenness due to the relative positional deviation between the optical function unit 2 and the light emitting element 11 and the wavelength conversion unit 12. By providing the light-shielding scattering layer 403, the light-shielding scattering layer 403 relaxes the luminance concentration in the flat surface portion 1y, and also realizes a feature that the luminance unevenness of the light emitting module 400 can be suppressed.

1-3. Modification 3 of the first embodiment
FIG. 10A is an enlarged cross-sectional view of the light emitting module 500 according to the modified example 3. FIG. 10B shows a plan view, a vertical sectional view, a horizontal sectional view, and a bottom view of the light guide plate 501 used in the light emitting module 500, respectively. In FIG. 10B, the recess 501a of the optical function unit 2 has a truncated cone shape in which the inclination angle (α) of the inclined surface 501x is constant from the outer peripheral portion toward the central portion and the flat portion 501y is provided in the central portion, and light is shielded. The outer shape of the scattering layer 3 is made larger than the outer shape of the optical function unit 2. In this light emitting module 500, the luminance concentration of the transmitted light of the optical function unit 2 can be alleviated by the light-shielding scattering layer 3 larger than the optical function unit 2, and the luminance unevenness can be suppressed. Further, since the light-shielding scattering layer 3 is larger than the optical function unit 2, it is possible to prevent a decrease in luminance unevenness due to a relative positional deviation between the light-shielding scattering layer 3 and the optical function unit 2.

1-4. Modification 4 of Embodiment 1
FIG. 11A is an enlarged cross-sectional view of the light emitting module 600 according to the modified example 4. FIG. 11B shows a plan view, a vertical sectional view, a horizontal sectional view, and a bottom view of the light guide plate 601 used in the light emitting module 600, respectively. In FIG. 11A, the recess 601a of the optical functional unit 2 has a constant inclination angle (α) of the inclined surface 601x from the outer peripheral portion toward the central portion, and a flat surface portion is not provided in the central portion. As a form, the outer shape of the light-shielding scattering layer 3 is made larger than the outer shape of the optical function unit 2. In this light emitting module 600, the luminance concentration of the transmitted light of the optical function unit 2 can be alleviated by the light-shielding scattering layer 3 larger than the optical function unit 2, and the luminance unevenness can be suppressed. Further, since the light-shielding scattering layer 3 is larger than the optical function unit 2, it is possible to prevent a decrease in luminance unevenness due to a relative positional deviation between the light-shielding scattering layer 3 and the optical function unit 2.

1-5. Modification 5 of the first embodiment
FIG. 12 is an enlarged cross-sectional view of the light emitting module 700 according to the modified example 5. In the light emitting module 700 of FIG. 12, the concave portion 1a of the optical functional unit 2 has a truncated cone shape having a flat surface portion 1y in the central portion, and the light-shielding scattering layer 703 has a different transmittance between the central portion and the outer peripheral portion in the opening portion. Is provided. In the light-shielding scattering layer 703, the film thickness of the central portion is made thicker than that of the outer peripheral portion, the transmittance of the central portion is made lower than that of the outer peripheral portion, the luminance concentration in the central portion of the optical function portion 2 is relaxed, and the light emitting module is used. The brightness unevenness of 700 is suppressed. The light-shielding scattering layer 703 can be provided by applying a pigment ink containing white powder to the surface of the translucent sheet 4 with a dot printer.

1-6. Modification 6 of Embodiment 1
FIG. 13 is an enlarged cross-sectional view of the light emitting module 800 according to the modified example 6. In the light emitting module 800 of FIG. 13, the concave portion 1a of the optical functional unit 2 has a truncated cone shape having a flat surface portion 1y in the central portion, and the light-shielding scattering layer 803 is integrated with the translucent sheet 804 to form the optical functional unit 2. It is placed in a position to cover it. In this translucent sheet 804, the mixing ratio of white powder such as titanium oxide added to the translucent sheet 804 is made higher in the region of the light-shielding scattering layer 803 than in the region of the translucent sheet 804 to transmit the transmittance. The specific region of the translucent sheet 804, that is, the region covering the optical functional unit 2, is set as the light-shielding scattering layer 803, which is lower than the optical sheet 804. In the light emitting module 800, a translucent sheet 804 having a smooth surface facing the light guide plate 1 can be laminated on the light guide plate 1, and a light-shielding scattering layer 803 can be provided at a position covering the optical functional unit 2.

1-7. Modification 7 of Embodiment 1
FIG. 14 is an enlarged cross-sectional view of the light emitting module 900 according to the modified example 7. In the light emitting module 900 of FIG. 14, the concave portion 1a of the optical functional unit 2 is formed into a truncated cone shape having a flat surface portion 1y in the central portion, and the light-shielding scattering layer 903 is integrated with the translucent sheet 904 to form the optical functional unit 2. It is placed in a position to cover it. In this translucent sheet 904, the mixing ratio of white powder such as titanium oxide added to the translucent sheet 904 is set higher in the region of the light-shielding scattering layer 903 than in the region of the translucent sheet 904 to transmit the transmittance. The light-shielding scattering layer 903 is provided in a specific region of the light-transmitting sheet 904 so as to be lower than the light-transmitting sheet 4, and the light-shielding scattering layer 903 sets the mixing ratio of the white powder in the central portion covering the flat surface portion 1y from the outer peripheral portion. The transmittance of the central portion is made lower than that of the outer peripheral portion, the brightness concentration in the central portion of the optical functional portion 2 is alleviated, and the brightness unevenness is suppressed in a more preferable state.

2. 2. Embodiment 2
FIG. 15A is an enlarged cross-sectional view of the light emitting module 1000 according to the second embodiment. FIG. 15B shows a plan view, a vertical sectional view, a horizontal sectional view, and a bottom view of the light guide plate 1001 used in the light emitting module 1000, respectively. The light guide plate 1001 of the light emitting module 1000 according to the second embodiment includes a light reflection recess 1001 g on the second main surface 1001d. The light reflecting recess 1001g faces the light emitting element 11 side, and includes a light reflecting surface 1001h that reflects light from the light emitting element 11. The light reflecting surface 1001h is a curved surface, and is the deepest in the middle between the two recesses 1001b. In the second embodiment, an example is shown in which substantially the entire area of the second main surface 1001d other than the recess 1001b is a curved surface, whereby the light from the light emitting element 11 can be efficiently reflected. However, the present invention is not limited to this, and a flat surface may be provided. FIG. 15A illustrates an example in which the depth of the light reflecting recess 1001g is deeper than that of the recess 1001b. As a result, the light from the light emitting element 11 can be efficiently reflected, and uniform surface light emission can be achieved.

Further, the light emitting module 1000 shown in FIG. 15A is provided with a flat surface portion 1001y in the central portion of the concave portion 1001a of the optical functional portion 1002 so that the inclination angle (α) of the inclined surface 1001x gradually increases from the outer circumference toward the center. It has a truncated cone shape. Further, in the light emitting module 1000, the outer shape of the light-shielding scattering layer 3 is larger than the outer shape of the optical function unit 1002, and the luminance unevenness due to the relative positional deviation between the optical function unit 1002 and the light-shielding scattering layer 3 is reduced. There is. In this light emitting module 1000, the luminance concentration of the transmitted light of the optical function unit 1002 can be alleviated by the light-shielding scattering layer 3 larger than the optical function unit 1002, and the luminance unevenness can be suppressed.

3. 3. Embodiment 3
FIG. 16A is an enlarged cross-sectional view of the light emitting module 1100 according to the third embodiment. FIG. 16B shows a plan view, a vertical sectional view, a horizontal sectional view, and a bottom view of the light guide plate 1101 used in the light emitting module 1100, respectively. Further, FIG. 16C is an enlarged view of the region surrounded by the broken line of the light guide plate 1101 shown in FIG. 16A. The light guide plate 1101 of the light emitting module 1100 according to the third embodiment is provided with one optical functional unit 1102 for one light emitting element 11, and a plurality of light reflecting recesses 1101 g are provided for one light emitting element 11. ing. The light reflecting recess 1101g faces the light emitting element 11 side, and includes a light reflecting surface 1101h that reflects light from the light emitting element 11. As the light guide plate 1101, an example including the first to fourth light reflection recesses 1101 g is shown here. The number of the light reflecting recesses 1101 g is not limited to this, and a plurality of two or more may be provided. A sealing member 13 is arranged in each light reflection recess 1101 g.

As shown in FIG. 16B, a first light reflection recess 1101ga having the largest depth from the second main surface 1101d is provided between the two recesses 1101b of the light guide plate 1101. The first light reflection recess 1101ga is provided in a square ring shape so as to surround the recess 1101b in a top view. A second light reflection recess 1101gb is arranged inside the first light reflection recess 1101ga. Further, a third light reflection recess 1101 gc is arranged inside the third light reflection recess 1101 gc. Further, a fourth light reflection recess 1101 gd is arranged inside the light emitting element 11 at a position closest to the light emitting element 11. The first to fourth light reflecting recesses each have a light reflecting surface 1101ha, 1101hb, 1101hc, 1101hd facing toward the light emitting element 11, and the light from the light emitting element 11 is transmitted by these light reflecting surfaces 1101h. It is reflected toward the first main surface 1101c side of 1101. The first light reflection recess 1101ga includes two light reflection surfaces 1101ha in order to reflect light from the two light emitting elements 11 arranged at positions sandwiching the first light reflection recess 1101ga. The second to fourth light reflection recesses include light reflection auxiliary surfaces 1101ib, 1101ic, and 1101id arranged on the side far from the light emitting element 11. These light reflection auxiliary surfaces 1101i are surfaces capable of reflecting the light reflected by the light reflection surfaces 1101h arranged at opposite positions.

The first light reflection recess 1101ga arranged at the position farthest from the light emitting element 11 is deeper than the second light reflection recess 1101gb inside the first light reflection recess 1101ga. As a result, among the light from the light emitting element 11, the light that is not blocked by the light reflecting surface of the second to fourth light reflecting recesses can be reflected. As described above, by making the depth of the light reflecting recess 1101 g arranged closer to the light emitting element 11 shallower, the light reflecting surface 1101h of each light reflecting recess 1101 g can be effectively used. The depth of the first light reflecting recess 1101ga is preferably deeper than the depth of the recess 1101b. As a result, the light from the light emitting element 11 can be efficiently reflected to obtain uniform surface light emission.

The angle of the light reflecting surface 1101h of each light reflecting recess 1101g can be designed according to various factors such as the purpose and application, the light distribution characteristics of the light emitting element 11, and the thickness of the light guide plate 1101. As an example, an example using a light guide plate 1101 made of polycarbonate having a thickness of 1.1 mm is shown. The recess 1101b is a square having a plan view of 0.5 mm × 0.5 mm and a depth of 0.1 mm. The distance between the adjacent recesses 1101b is 0.8 mm.

The first light reflecting recess 1101ga has a depth of 0.80 mm, and the light reflecting surface 1101ha is inclined 16 degrees with respect to the second main surface 1101d. The second light reflecting recess 1101 gb has a depth of 0.50 mm, and the light reflecting surface 1101 hb is inclined by 32 degrees with respect to the second main surface 1101 d. The third light reflecting recess 1101 gc has a depth of 0.31 mm, and the light reflecting surface 1101 hc is inclined by 45 degrees with respect to the second main surface 1101d. The fourth light reflecting recess 1101 gd has a depth of 0.15 mm, and the light reflecting surface 1101 hd is inclined by 58 degrees with respect to the second main surface 1101 d.

Further, the light emitting module 1100 shown in FIG. 16A has a shape in which the recess 1101a of the optical function unit 1102 has a rectangular opening and the inclination angle (α) of the inclined surface 1101x gradually increases from the outer periphery toward the center. It has a quadrangular pyramid shape with a flat surface portion 1101y provided in the center. Further, the square corner portion of the opening portion and the corner portion of the light source portion including the light emitting element 11 are arranged at positions shifted by 45 degrees with respect to the optical axis. Further, in the light emitting module 1100, the outer shape of the light-shielding scattering layer 3 is larger than the outer shape of the optical function unit 1102, and the luminance unevenness due to the relative positional deviation between the optical function unit 1102 and the light-shielding scattering layer 3 is reduced. There is. In this light emitting module 1100, the luminance concentration of the transmitted light of the optical functional unit 1102 can be alleviated by the light-shielding scattering layer 3 larger than the optical functional unit 1102, and the luminance unevenness can be suppressed.

4. Embodiment 4
FIG. 17 is an enlarged cross-sectional view of the light emitting module 1200 according to the fourth embodiment. In the light emitting module 1200 shown in this figure, the optical functional unit 1202 includes a light reflecting layer 19 made of a light reflecting material on the surface of the recess 1a of the light guide plate 1. As such a light-reflecting material, for example, a white resin can be used. The optical function unit 1202 shown in FIG. 17 is a surface of a recess 1a provided in the light guide plate 1, and a light-reflecting material is applied to a region from the central portion (upper end portion in the figure) of the inclined surface 1x to the flat surface portion 1y. The light reflecting layer 19 is provided with a predetermined thickness. However, the light reflecting layer may be provided on the entire recess or only on the flat surface. Further, although the light reflecting layer shown in the figure has a uniform overall thickness, it can be gradually increased from the outer peripheral portion to the central portion of the recess. For example, the light reflecting layer may be formed gradually thinner toward the outer peripheral portion in the region facing the inclined surface while keeping the thickness of the region facing the flat surface portion constant.
As described above, in the light emitting module 1200 provided with the light reflecting layer 19 on the surface of the recess 1a, the light reflecting layer 19 is provided in the central portion of the optical functional unit 1202, and the light-shielding scattering layer 3 covering the optical functional unit 1202 is provided. Due to the synergistic effect of, it is possible to realize the feature that the concentration of brightness in the central part can be further alleviated and the unevenness of brightness can be reduced.

Although some embodiments of the present invention have been exemplified above, it is needless to say that the present invention is not limited to the above-described embodiments and can be arbitrary as long as it does not deviate from the gist of the present invention. ..
The disclosure of the present specification may include the following aspects.
(Aspect)
A translucent light guide plate having a first main surface that is a light emitting surface that radiates light to the outside and a second main surface that is opposite to the first main surface.
A light emitting module provided with a light emitting element arranged on the second main surface of the light guide plate and irradiating light toward the light guide plate.
The light guide plate has an optical functional unit that is larger than the light emitting surface of the light emitting element and is arranged on the optical axis of the light emitted from the light emitting element, which is the first main surface.
A light-shielding scattering layer is arranged on the optical axis of the light emitting element on the first main surface side of the light guide plate.
A light emitting module characterized in that a light-shielding scattering layer covers an optical function portion in a plan view.
(Aspect 2)
The light emitting module according to the first aspect.
The light guide plate is between the light emitting elements arranged adjacent to each other, and the partition recess is arranged on the second main surface, and the partition recess has a plurality of inclined surfaces continuous with the second main surface.
A light emitting module characterized in that the outer shape of the optical function unit is smaller than the area surrounded by the partition recesses in a plan view.
(Aspect 3)
The light emitting module according to the first or second aspect.
A wavelength conversion unit that converts the light of the light emitting element into wavelength and incidents on the light guide plate is arranged between the light emitting element and the light guide plate.
A light emitting module characterized in that the outer shape of the optical function unit is larger than the outer shape of the wavelength conversion unit in a plan view.
(Aspect 4)
The light emitting module according to any one of aspects 1 to 3.
A light emitting module characterized in that the optical functional part is a concave portion, and the inner peripheral surface of the optical functional part includes an inclined surface that approaches the light emitting element toward the central part.
(Aspect 5)
The light emitting module according to the fourth aspect.
A light emitting module characterized in that the inclined surface of the optical function portion has a shape in which the inclination angle (α) gradually increases toward the central portion.
(Aspect 6)
The light emitting module according to the fourth or fifth aspect.
A light emitting module characterized in that the optical function portion has a flat portion at the bottom.
(Aspect 7)
The light emitting module according to the sixth aspect.
A light emitting module characterized in that a flat portion of an optical function unit is arranged on the optical axis of a light emitting element.
(Aspect 8)
The light emitting module according to any one of aspects 1 to 7.
It has a translucent sheet laminated on the first main surface of the light guide plate, and has.
A light emitting module characterized in that a light-shielding scattering layer is provided on a translucent sheet.
(Aspect 9)
The light emitting module according to the eighth aspect.
A light emitting module characterized in that the translucent sheet is a scattering sheet that scatters and transmits transmitted light.
(Aspect 10)
The light emitting module according to the ninth aspect.
A light emitting module characterized in that a light-shielding scattering layer is joined to a surface facing a light guide plate of a translucent sheet.
(Aspect 11)
The light emitting module according to the sixth or seventh aspect.
A light emitting module characterized in that the outer shape of the light-shielding scattering layer is larger than the outer shape of the flat surface portion provided in the optical function portion in a plan view.
(Aspect 12)
The light emitting module according to any one of aspects 1 to 11.
A light emitting module characterized in that the outer shape of the light-shielding scattering layer is larger than the outer shape of the optical function unit in a plan view.

The light emitting module according to the present disclosure can be used, for example, as a backlight of a liquid crystal display device.

3000 ... Liquid crystal display device 100, 200, 300, 400, 500, 600, 700, 800, 900,
1000, 1100, 1200 ... Light emitting module 110a ... Lens sheet 110b ... Lens sheet 110c ... Diffusion sheet 120 ... Liquid crystal panel 1, 201, 501, 601, 1001, 1101 ... Light guide plate 1a, 501a, 601a, 1001a, 1101a ... Recess 1b , 1001b, 1101b ... Recesses 1c, 1001c, 1101c ... First main surface 1d, 201d, 1001d, 1101d ... Second main surface 1e ... Sectional recesses 1001g, 1101g ... Light reflection recesses 1101ga ... First light reflection recesses 1101gb ... Second Light reflection recess 1101gc ... Third light reflection recess 1101gd ... Fourth light reflection recess 1001h, 1101h ... Light reflection surface 1101ha, 1101hb, 1101hc, 1101hd ... Light reflection surface 1101i, 1101ib, 1101ic, 1101id ... Light reflection auxiliary surface 1x, 501x , 601x, 1001x, 1101x ... Inclined surface 1y, 501y, 601y, 1001y, 1101y ... Flat surface portion 2, 502, 602, 1002, 1102, 1202 ... Optical function unit 3, 303, 403, 703, 803, 903 ... Light-shielding scattering Layers 4, 804, 904 ... Translucent sheet 10 ... Light emitting element unit 11 ... Light emitting element 11a ... Light emitting surface 11b ... Electrode 11c ... Main light emitting surface 11d ... Electrode forming surface 12 ... Wavelength conversion unit 13 ... Sealing member 13a ... Sealing Material 14 of the stop member ... Translucent joining member 14a ... Material of the translucent joining member 15 ... Wiring 15a ... Metal film 16 ... Light-reflecting member 17 ... Translucent adhesive member 19 ... Light-reflecting layer 20 ... Wiring substrate 20a ... Base material 20b ... Wiring layer 20c ... Conductive member 20e ... Connector 30 ... Frame 41 ... Base sheet 42 ... Plate

Claims (8)

Wiring board and
A translucent light guide plate having a first main surface that is a light emitting surface that radiates light to the outside and a second main surface that is opposite to the first main surface.
A light emitting module provided with a light emitting element arranged on the wiring board and irradiating light toward the light guide plate.
The light guide plate has a function of spreading light incident on the light guide plate, which is larger than the light emitting surface of the light emitting element, in the optical axis of the light emitted from the light emitting element, which is the first main surface. The optical function unit with
The optical functional portion is a concave portion, and the inner peripheral surface of the optical functional portion includes an inclined surface that approaches the light emitting element toward the central portion.
The optical functional portion has a flat portion at the bottom, and the optical functional portion has a flat portion.
It has a translucent sheet laminated on the first main surface of the light guide plate, and has a translucent sheet.
The translucent sheet is a scattering sheet that scatters and transmits transmitted light.
A light-shielding scattering layer is arranged on the optical axis of the light emitting element on the first main surface side of the light guide plate.
The light-shielding scattering layer is in the shape of a flat plate having a uniform thickness, and is joined to the surface of the translucent sheet facing the light guide plate.
A light emitting module in which the outer shape of the light-shielding scattering layer is larger than the outer shape of the flat surface portion provided in the optical functional portion in a plan view, and the light-shielding scattering layer covers the optical functional portion. The light emitting module according to claim 1.
The light guide plate is located between the light emitting elements arranged adjacent to each other, and a partition recess is arranged on the second main surface, and the partition recess has a plurality of inclinations continuous with the second main surface. Has a face,
A light emitting module in which the outer shape of the optical functional unit is smaller than the area surrounded by the compartment recess in a plan view. The light emitting module according to claim 1 or 2.
A wavelength conversion unit that converts the light of the light emitting element into wavelength and incidents on the light guide plate is arranged between the light emitting element and the light guide plate.
A light emitting module in which the outer shape of the optical function unit is larger than the outer shape of the wavelength conversion unit in a plan view. The light emitting module according to any one of claims 1 to 3.
A light emitting module having a shape in which the inclination angle α formed by the inclined surface of the optical function portion and the first main surface of the light guide plate gradually increases toward the central portion. The light emitting module according to claim 4.
A light emitting module in which the flat surface portion of the optical functional portion is arranged on the optical axis of the light emitting element. The light emitting module according to any one of claims 1 to 5.
A light emitting module in which the translucent sheet is a scattering sheet that scatters and transmits transmitted light. The light emitting module according to any one of claims 1 to 6.
A uniform flat light emitting module having a light-shielding scattering layer having a thickness of 50 μm or more and 500 μm or less . The light emitting module according to any one of claims 1 to 7.
A light emitting module in which the outer shape of the light-shielding scattering layer is larger than the outer shape of the optical functional unit in a plan view.

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