JP7078865B2 - Luminous module - Google Patents

Description

The present disclosure relates to a light emitting module.

A light emitting device using a light emitting element such as a light emitting diode is widely used as a backlight for a display such as a liquid crystal display device. In particular, a direct-type backlight is used to increase the brightness of the display or to increase the contrast of the image by performing partial drive.

In recent years, in some applications, it has been required to make the thickness of the display provided with the direct-type backlight as small as possible, and therefore, the thickness of the direct-type backlight may also be required to be as small as possible. For example, Patent Document 1 discloses a light emitting module in which a lens for diffusing light is provided on a light guide plate and a light emitting element is bonded to the light guide plate. With such a configuration, a thin light emitting module can be realized.

Japanese Unexamined Patent Publication No. 2018-133304

In a light emitting module in which a light emitting element is bonded to a light guide plate, it may be required to partially adjust the light distribution characteristics of the light emitting surface. The present disclosure provides a light emitting module capable of partially adjusting the light distribution characteristics of the light emitting surface.

The light source module according to an embodiment of the present disclosure is arranged one-dimensionally or two-dimensionally with a first main surface and a second main surface located on the opposite side of the first main surface, and at least one first unit. A light source including a region, a plurality of unit regions including a plurality of second unit regions, and a plurality of first recesses located on the first main surface and corresponding to the plurality of unit regions, and the guide plate. A plurality of light sources provided on the first main surface of the optical plate, each of which is a plurality of light sources arranged in the first recess corresponding to one of the plurality of unit regions, and the plurality of light sources. In each of the unit regions, a translucent member arranged in the first recess so as to cover at least a part of the side surface of the light source is provided, and in the second unit region, the optical axis of the light source is set. It coincides with the center of the first recess on the first main surface, and in at least one first unit region, the optical axis of the light source deviates from the center of the first recess on the first main surface. In the at least one first unit region, the upper surface of the translucent member has a first recessed portion on the bottom surface side of the first recessed portion.

According to the present disclosure, there is provided a light emitting module capable of partially adjusting the light distribution characteristics of the light emitting surface.

FIG. 1A is a perspective view showing a first embodiment of a light emitting module. FIG. 1B is a top view of the light emitting module shown in FIG. 1A. FIG. 1C is a bottom view of the light emitting module shown in FIG. 1A. FIG. 2A is a top view of the light guide plate of the light emitting module shown in FIG. 1A. FIG. 2B is a bottom view of the light guide plate of the light emitting module shown in FIG. 1A. FIG. 2C is a cross-sectional view of the light guide plate of the light emitting module shown in FIG. 1A. FIG. 3A is a cross-sectional view of the first light emitting unit of the light emitting module shown in FIG. 1A. FIG. 3B is a top view of the first light emitting unit of the light emitting module shown in FIG. 1A. FIG. 3C is a cross-sectional view of the first light emitting unit of the light emitting module shown in FIG. 1A, showing another form of the light guide plate. FIG. 4A is a cross-sectional view of the second light emitting unit of the light emitting module shown in FIG. 1A. FIG. 4B is a top view of the second light emitting unit of the light emitting module shown in FIG. 1A. FIG. 5A is a cross-sectional view of the light source 20 of the light emitting module shown in FIG. 1A. FIG. 6 is a schematic cross-sectional view showing another example of a light source applicable to the light emitting unit of the light emitting module according to the embodiment of the present disclosure. FIG. 6 is a schematic cross-sectional view showing still another example of the configuration of the light source applicable to the light emitting unit. FIG. 6 is a schematic cross-sectional view showing still another example of the configuration of the light source applicable to the light emitting unit. FIG. 6 is a schematic cross-sectional view showing still another example of the configuration of the light source applicable to the light emitting unit. FIG. 6 is a schematic cross-sectional view showing still another example of the configuration of the light source applicable to the light emitting unit. FIG. 6 is a schematic cross-sectional view showing still another example of the configuration of the light source applicable to the light emitting unit. FIG. 6 is a schematic cross-sectional view showing still another example of the configuration of the light source applicable to the light emitting unit. FIG. 6 is a schematic cross-sectional view showing still another example of the configuration of the light source applicable to the light emitting unit. FIG. 6 is a schematic cross-sectional view showing still another example of the configuration of the light source applicable to the light emitting unit. FIG. 6 is a schematic cross-sectional view showing still another example of the configuration of the light source applicable to the light emitting unit. FIG. 6 is a schematic cross-sectional view showing still another example of the configuration of the light source applicable to the light emitting unit. FIG. 6 is a schematic cross-sectional view showing still another example of the configuration of the light source applicable to the light emitting unit. FIG. 6 is a schematic cross-sectional view showing still another example of the configuration of the light source applicable to the light emitting unit. FIG. 6 is a schematic cross-sectional view showing still another example of the configuration of the light source applicable to the light emitting unit. FIG. 6 is a schematic cross-sectional view showing still another example of the configuration of the light source applicable to the light emitting unit. FIG. 6A is an enlarged cross-sectional view of the first light emitting unit of the light emitting module shown in FIG. 1A. FIG. 6B is another enlarged cross-sectional view of the first light emitting unit of the light emitting module shown in FIG. 1A. FIG. 6C is an enlarged cross-sectional view of the second light emitting unit of the light emitting module shown in FIG. 1A. FIG. 6D is another enlarged cross-sectional view of the second light emitting unit of the light emitting module shown in FIG. 1A. FIG. 6E is an enlarged cross-sectional view showing another form of the first light emitting unit of the light emitting module shown in FIG. 1A. FIG. 6F is an enlarged cross-sectional view showing still another form of the first light emitting unit of the light emitting module shown in FIG. 1A. FIG. 6G is a schematic enlarged cross-sectional view showing another example of the structure of the light guide plate 10 of the first light emitting unit 101A. FIG. 6H is a schematic enlarged cross-sectional view showing another example of the structure of the light guide plate 10 of the second light emitting unit 101B. FIG. 7A is a diagram illustrating the light distribution characteristics of the first light emitting unit of the light emitting module shown in FIG. 1A. FIG. 7B is a diagram illustrating the light distribution characteristics of the second light emitting unit of the light emitting module shown in FIG. 1A. FIG. 8A is a top view showing a configuration example of the light emitting module. FIG. 8B is a top view showing another configuration example of the light emitting module. FIG. 8C is a top view showing still another configuration example of the light emitting module. FIG. 8D is a top view showing still another configuration example of the light emitting module. FIG. 9 is a top view showing an example of the backlight of the first embodiment. FIG. 10A is a schematic top view of the light emitting module according to the second embodiment of the present disclosure. FIG. 10B is a top view of the light guide plate of the light emitting module shown in FIG. 10A. FIG. 10C is an enlarged cross-sectional view of the third light emitting unit of the light emitting module shown in FIG. 10A. FIG. 11 is an enlarged cross-sectional view showing another example of the shape of the translucent member of the second light emitting unit. FIG. 12 is an enlarged cross-sectional view showing still another example of the shape of the translucent member of the second light emitting unit. FIG. 13 is an enlarged cross-sectional view showing still another example of the shape of the translucent member of the second light emitting unit.

When a light emitting unit in which a light emitting element is bonded to a light guide plate as disclosed in Patent Document 1 is used as a direct type backlight of a display, for example, one light emitting unit corresponding to the size of the screen of the display is used. Can be considered. In this case, it is necessary to arrange and join a large number of light emitting elements on one light guide plate corresponding to the size of the screen. For this reason, for example, if even one light emitting element that does not light up is joined to one light guide plate, or if the light emitting element is not arranged at an appropriate position, the light emitting unit may be defective as a whole, and the manufacturing yield may be reduced. Can be low.

In order to avoid such a decrease in manufacturing yield, it is conceivable to divide the screen of the display into a plurality of areas, manufacture a plurality of light emitting units having a size corresponding to the divided areas, and arrange the plurality of light emitting units. Will be. For example, first, a small light emitting unit is manufactured by arranging and joining a plurality of light emitting elements on a rectangular light guide plate having a side of several centimeters. After that, by arranging a plurality of small light emitting units in two dimensions, it can be used as a backlight corresponding to a large screen as a whole.

Since the number of light emitting elements bonded to this small light emitting unit is smaller than the number of light emitting elements when the light emitting elements are arranged and joined on a light guide plate having the size of the entire screen, it is possible to increase the manufacturing yield. Is. Further, by differently arranging the number of small light emitting units, it is possible to correspond to the screens of displays of various sizes, and a light emitting unit having a light guide plate of a size corresponding to each screen size can be provided. It is possible to reduce the manufacturing cost as compared with the case of preparing.

Further, since it can be used for displays of various sizes, such a light emitting module can be used for various purposes such as displaying an image and displaying information on various devices and vehicles such as automobiles. In this case, depending on the application, if the light distribution characteristics can be partially adjusted on the emission surface of the light emitting module, the light emitting module can be adapted to more various applications or provide a new usage mode different from the conventional one. It is thought to get.

The present disclosure provides a novel light emitting unit in view of such a problem. Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. The following embodiments are examples, and the light emitting module according to the present disclosure is not limited to the following embodiments. For example, the numerical values, shapes, materials, steps, the order of the steps, and the like shown in the following embodiments are merely examples, and various modifications can be made as long as there is no technical contradiction. Each embodiment described below is merely an example, and various combinations are possible as long as there is no technical contradiction.

The dimensions, shapes, etc. of the components shown in the drawings may be exaggerated for the sake of clarity, and may not reflect the dimensions, shapes, and magnitude relationships between the components in the actual light emitting module. In addition, some elements may be omitted in order to prevent the drawings from becoming excessively complicated.

In the following description, components having substantially the same function are indicated by common reference numerals, and the description may be omitted. In the following description, terms indicating a specific direction or position (eg, "top", "bottom", "right", "left" and other terms including those terms) may be used. However, those terms use relative orientation or position in the referenced drawings for clarity only. If the relative directions or positional relationships in terms such as "upper" and "lower" in the referenced drawings are the same, the drawings other than the present disclosure, actual products, manufacturing equipment, etc. are the same as the referenced drawings. It does not have to be an arrangement. In the present disclosure, "parallel" includes the case where two straight lines, sides, surfaces, etc. are in the range of about 0 ° to ± 5 ° unless otherwise specified. Further, in the present disclosure, "vertical" or "orthogonal" includes the case where two straight lines, sides, surfaces, etc. are in the range of about 90 ° to ± 5 ° unless otherwise specified.

<First Embodiment>
(Structure of light emitting module 201)
FIG. 1A is a perspective view showing a light emitting module 201 which is the first embodiment of the light emitting module of the present disclosure. 1B and 1C are a top view and a bottom view of the light emitting module 201. The light emitting module 201 has a plate shape as a whole. The light emitting module 201 includes a light guide plate 210, a plurality of light sources 20, and a light reflecting layer 220. For convenience of explanation, FIGS. 1A also show arrows indicating the X, Y, and Z directions orthogonal to each other. Other drawings of the present disclosure may also illustrate arrows pointing in these directions. The X and Y directions are also the first and second directions.

2A, 2B and 2C are a top view, a bottom view and a cross-sectional view of the light guide plate 210. The light guide plate 210 has a second main surface 210b located on the opposite side of the first main surface 210a and the first main surface 210a, and is arranged in a plurality of first recesses 11 provided in the first main surface 210a. It is provided with a light guide structure that emits light emitted from a plurality of light sources 20 to be emitted from a second main surface 210b.

The light reflecting layer 220 reflects the light emitted from the light source 20 on the first main surface 210a. The second main surface 210b is a light emitting surface of the light emitting module 201. Typically, the second main surface 210b of the light guide plate 210 has a rectangular shape. Here, the above-mentioned X and Y directions coincide with one and the other of the rectangular rectangular sides of the light guide plate 210 that are orthogonal to each other. The length of one side of the rectangular shape of the second main surface 210b is, for example, in the range of 1 cm or more and 200 cm or less. In a typical embodiment of the present disclosure, one rectangular side of the second main surface 210b of the light guide plate 210 has a length of 10 mm or more and 30 mm or less. The rectangular vertical and horizontal lengths of the second main surface 210b can be, for example, approximately 24.3 mm and 21.5 mm, respectively. Alternatively, the rectangular vertical and horizontal lengths of the second main surface 210b may be approximately 21.7 mm and 24.0 mm, respectively.

As shown in FIGS. 2A and 2B, the first main surface 210a and the second main surface 210b of the light guide plate 210 are divided into a plurality of unit regions 211 arranged one-dimensionally or two-dimensionally, and each unit region. 211 constitutes the light emitting unit 101 (see FIG. 1A). In this example, the light guide plate 210 includes 16 unit regions 211 arranged in two dimensions, and the 16 unit regions 211 are arranged in 4 rows and 4 columns. The number and arrangement of the unit regions 211 included in the light guide plate 210, that is, the number and arrangement of the light emitting units 101 included in the light emitting module 201 are arbitrary and are not limited to the configurations shown in FIGS. 1A to 1C and the like.

The plurality of light emitting units 101 includes at least one first light emitting unit 101A. In this embodiment, four first light emitting units 101A are included. Further, the plurality of light emitting units 101 include a second light emitting unit 101B. In the configurations exemplified in FIGS. 1B and 1C, the plurality of light emitting units 101 include twelve second light emitting units 101B, and these second light emitting units 101B are arranged in 3 rows and 4 columns. Here, as shown in FIGS. 2A and 2B, the plurality of unit regions 211 include four first unit regions 211A and twelve second unit regions 211B. Of the plurality of unit regions 211, the first unit region 211A corresponds to the first light emitting unit 101A, and the second unit region 211B corresponds to the second light emitting unit 101B.

3A and 3B are a cross-sectional view and a top view of the first light emitting unit 101A, and FIGS. 4A and 4B are a cross-sectional view and a top view of the second light emitting unit 101B. As will be described in detail below, the position where the light source 20 is fixed to the light guide plate 210 is different between the first light emitting unit 101A and the second light emitting unit 101B. In the second light emitting unit 101B, the center of the first recess 11 provided on the first main surface 210a of the light guide plate 210 and the optical axis of the light source 20 are substantially aligned, whereas in the first light emitting unit 101A, the optical axis is substantially aligned. The light source 20 is joined to the first main surface 210a side of the light guide plate 210 with the optical axis shifted from the center of the first recess 11. In the example shown in FIG. 3, as shown by the arrow SH in FIG. 3B, the position of the optical axis of the light source 20 (indicated by a black circle in FIG. 3B) is deviated from the center of the first recess 11 in the + Y direction of the figure. There is. As a result, the first light emitting unit 101A and the second light emitting unit 101B can realize different light distribution characteristics.

Hereinafter, the structures of the first light emitting unit 101A and the second light emitting unit 101B will be described in detail. Hereinafter, when the first light emitting unit 101A and the second light emitting unit 101B are generically referred to, they may be referred to as a light emitting unit 101. Further, when the translucent members 50A and 50B are generically referred to, these may be referred to as the translucent member 50.

The light emitting unit 101 includes a light guide plate 10, a light source 20, and a translucent member 50. The light emitting unit 101 may further include a light reflecting layer 30, a light reflecting member 40, and a wiring layer 60.

[Light guide plate 10]
The light guide plate 10 is a portion corresponding to each unit region 211 of the light guide plate 210 shown in FIG. 1A or the like. The light guide plate 10 supports the light source 20. Further, the light guide plate 10 includes a light guide structure for emitting light emitted from the light source 20 from one surface of the light guide plate 10 as uniformly as possible. Specifically, the light guide plate 10 has a first main surface 10a and a second main surface 10b located on the opposite side of the first main surface 10a, and the first main surface 10a is provided with a first recess 11. There is. The first recess 11 has, for example, a quadrangular pyramid whose upper surface is smaller than the bottom surface, and the upper surface is located at the bottom of the first recess 11. In the present embodiment, the quadrangular pyramid shape is arranged so that the four sides of the upper surface and the bottom surface are substantially parallel to the four sides of the unit region 211. However, the quadrangular pyramid shape may be arranged so that the diagonal lines of the upper surface and the bottom surface are substantially parallel to the four sides of the unit region 211. A light source 20 is arranged in the first recess 11.

The first main surface 10a of the light guide plate 10 may have a curved surface portion 10c in order to reflect light traveling toward the first main surface 10a. The curved surface portion 10c is provided, for example, in the peripheral region of each unit region 211 of the first main surface 10a. By arranging the light reflection layer 30 on the first main surface 10a, the light incident on the first main surface 10a at a shallow angle is totally reflected on the curved surface portion 10c toward the second main surface 10b, and the light is reflected. Extraction efficiency is improved.

The light guide plate 10 may include a lens structure for adjusting the light distribution of the light emitted from the second main surface 10b. Specifically, the lens structure is a second recess 12 provided on the second main surface 10b. The second recess 12 includes, for example, a first portion 12c having a conical shape and a second portion 12d having a truncated cone shape. The tip of the conical shape is located on the inner side of the light guide plate 10, and the lower surface of the conical shape of the first portion 12c is in contact with the upper surface of the truncated cone shape of the second portion 12d. In a plan view, that is, the center of the second recess 12 as seen from the second main surface 10b or the first main surface 10a preferably coincides with the center of the first recess 11.

The lens structure included in the light guide plate 10 is not limited to the above example, and the light guide plate 10 may include a lens structure having another shape. For example, as shown in FIG. 3C, the second recess 12 which is the lens structure of the light guide plate 10 may include a first portion 12c having a truncated cone shape and a second portion 12d having a truncated cone shape.

The lens structure controls the emission direction of light by utilizing the refraction of light at the boundary between the inner side surface and the bottom surface of the second recess 12 and the external environment. In the present embodiment, the light reflecting member 40 is arranged in the first portion 12c of the second recess 12.

The light guide plate 10 is formed of a thermoplastic resin such as acrylic, polycarbonate, cyclic polyolefin, polyethylene terephthalate and polyester, a thermosetting resin such as epoxy and silicone, and a translucent material such as glass. For example, using a mold having a shape corresponding to the first concave portion 11, the curved surface portion 10c, and the second concave portion 12, it is possible to form a light guide plate 210 in which a plurality of light guide plates 10 are two-dimensionally connected by injection molding or the like. .. In a typical embodiment of the present disclosure, the center of the first recess 11 and the center of the second recess 12 in a plan view are aligned. According to the molding method using a mold having a convex portion corresponding to the first concave portion 11 and the second concave portion 12 inside the cavity, the center of the first concave portion 11 and the center of the second concave portion 12 of each light emitting unit 101 It is also relatively easy to match.

[Light reflective member 40]
When the light guide plate 10 includes the second recess 12, the light reflecting member 40 may be arranged in the first portion 12c of the second recess 12. The light reflective member 40 is arranged in the first portion 12c of the second recess 12. By arranging the light reflecting member 40 above the light source 20, a part of the light emitted from the light source can be reflected to the first main surface 10a side. In the configuration exemplified in FIG. 3A, since the first portion 12c has a conical shape, the light reflected at the interface between the light guide plate 10 and the light reflecting member 40 is diffused in a wider range in the light guide plate 10. Proceed to the first main surface 10a side. Therefore, it is possible to more efficiently diffuse the light from the light source 20 into the plane of the light guide plate 10. Further, since the light reflecting member 40 is arranged so as to face the light source 20, the brightness directly above the light source 20 on the second main surface 10b of the light guide plate 10 becomes extremely high as compared with other regions. Can be suppressed. Further, since the light reflecting member 40 is selectively formed inside the first portion 12c of the second recess 12, it is possible to prevent the brightness directly above the light source 20 from being lowered more than necessary. As a result, it is possible to obtain light with improved uniformity while reducing the thickness of the entire light emitting unit 101.

The light-reflecting member 40 is formed of a light-reflecting material such as a resin material in which a light-reflective filler is dispersed. Here, in the present specification, "reflectivity" and "light reflectivity" mean that the reflectance at the emission peak wavelength of the light source 20 is 60% or more. It is more beneficial when the reflectance of the light reflective member 40 at the emission peak wavelength of the light source 20 is 70% or more, and it is even more useful when the reflectance is 80% or more.

As the base material of the resin material for forming the light-reflecting member 40, a silicone resin, a phenol resin, an epoxy resin, a BT resin, a polyphthalamide (PPA) or the like can be used. As the light-reflecting filler, metal particles or particles of an inorganic material or an organic material having a higher refractive index than the base material can be used. Examples of light-reflecting fillers include titanium dioxide, silicon oxide, zirconium dioxide, potassium titanate, aluminum oxide, aluminum nitride, boron nitride, murite, niobium oxide, barium sulfate particles, or yttrium oxide and gadolinium oxide. Particles of various rare earth oxides and the like. It is beneficial if the light-reflecting member 40 has a white color.

The distribution of the light-reflecting filler in the light-reflecting member 40 may be substantially constant in the light-reflecting member 40, or may have a bias or a gradient. For example, in the process of forming the light-reflecting member 40, the filler may settle or separate from the base material before the base material is cured, so that the distribution of the light-reflecting filler in the light-reflecting member 40 may be biased.

When the number density of fillers defined by the number of fillers per unit area in a plan view is relatively high near the center as compared with the vicinity of the outer edge of the light reflecting member 40, the brightness of the region directly above the light source 20 becomes high. It is easy to suppress the local extreme increase, which is beneficial.

[Light reflective layer 30]
The light reflecting layer 30 is a portion corresponding to each unit region 211 of the light reflecting layer 220 shown in FIG. 1A or the like, and covers the first main surface 10a of the light guide plate 10. As shown in FIG. 3A, the light reflecting layer 30 may cover the translucent member 50 located inside the first recess. The light reflecting layer 30 may cover the entire translucent member 50. The light reflecting layer 30 can be formed by using, for example, a material exemplified as the material of the light reflecting member 40. By covering the first main surface 10a with the light reflecting layer 30, the light incident on the first main surface 10a of the light guide plate 10 can be reflected to the second main surface 10b side.

[Wiring layer 60]
The wiring layer 60 is located on the first main surface 30a of the light reflecting layer 30, which corresponds to the lower surface of the light emitting unit 101, and is electrically connected to the light source 20. As shown in FIG. 1C, the wiring layer 60 electrically connects the light source 20 of each light emitting unit 101 on the first main surface 30a of the light reflecting layer 30 of the light emitting module 201. The circuit formed by the wiring layer 60 is determined according to the driving method of each light emitting unit 101 of the light emitting module 201. For example, when each light emitting unit 101 of the light emitting module 201 is driven at the same timing, eight series circuits in which two of the light sources 20 of the light emitting units 101 arranged in 4 rows and 4 columns are connected in series are connected in parallel. You may connect. Alternatively, the light sources 20 of the light emitting units 101 arranged in 4 rows and 4 columns may be divided into two or more groups, and the circuit may be configured to drive them at the same time. The wiring layer 60 can be typically composed of a single-layer film or a laminated film formed of a metal such as Cu.

[Light source 20]
FIG. 5A is a cross-sectional view of the light source 20. The light source 20 is arranged in the first recess 11 of the light guide plate 10. The light source 20 includes a light emitting element 21, a wavelength conversion member 22, a joining member 23, and a light reflecting member 24.

A typical example of the light emitting element 21 is an LED. The light emitting element 21 has a main body portion 21 m including a support substrate such as sapphire or gallium nitride and a semiconductor laminated structure on the support substrate. The semiconductor laminated structure includes an n-type semiconductor layer and a p-type semiconductor layer, and an active layer sandwiched between them. The semiconductor laminated structure may include a nitride semiconductor (In _x Ally Ga _{1-xy N} , 0 ≦ x, 0 ≦ y, x + y ≦ 1) capable of emitting light in the ultraviolet to visible region. The light emitting device 21 further has an electrode 21t electrically connected to the n-type semiconductor layer and the p-type semiconductor layer.

The light emitting element 21 may be an element that emits blue light or an element that emits white light. The light emitting elements 21 of the plurality of light emitting units 101 may include elements that emit light of different colors from each other. For example, the light emitting element 21 of the plurality of light emitting units 101 may include an element that emits red light, an element that emits blue light, and an element that emits green light. In this embodiment, an LED that emits blue light is exemplified as the light emitting element 21.

The shape of the light emitting element 21 in a plan view is typically a rectangular shape. The length of one side of the rectangular shape of the light emitting element 21 is, for example, 1000 μm or less. The vertical and horizontal dimensions of the rectangular shape of the light emitting element 21 may be 500 μm or less. Light emitting elements with vertical and horizontal dimensions of 500 μm or less are easy to procure at low cost. Alternatively, the vertical and horizontal dimensions of the rectangular shape of the light emitting element 21 may be 200 μm or less. When the length of one side of the rectangular shape of the light emitting element 21 is small, it is advantageous for high-definition image expression, local dimming operation, etc. in application to the backlight unit of the liquid crystal display device. In particular, in a light emitting element having both vertical and horizontal dimensions of 250 μm or less, the area of the upper surface is small, so that the amount of light emitted from the side surface of the light emitting element is relatively large. Therefore, it is easy to obtain a butt wing type light distribution characteristic. Here, the butt-wing type light distribution characteristic is, in a broad sense, a light emission intensity distribution in which the light emission intensity is high in the angle direction in which the absolute value is larger than 0 °, where the optical axis perpendicular to the upper surface of the light emitting element is 0 °. Refers to light distribution characteristics as defined.

The wavelength conversion member 22 is arranged on the emission surface 21b of the light emitting element 21. The wavelength conversion member 22 absorbs at least a part of the light emitted from the light emitting element 21 and emits light having a wavelength different from the wavelength of the light emitted from the light emitting element 21. For example, the wavelength conversion member 22 wavelength-converts a part of the blue light from the light emitting element 21 to emit yellow light. According to such a configuration, white light is obtained by mixing the blue light that has passed through the wavelength conversion member 22 and the yellow light emitted from the wavelength conversion member 22. Further, the light emitted from the light emitting element 21 is basically introduced into the light guide plate 10 via the wavelength conversion member 22. Therefore, the light after the color mixing is diffused inside the light guide plate 10, and it is possible to take out, for example, white light having suppressed luminance unevenness from the second main surface 10b of the light guide plate 10. In this respect, when the light source 20 of the present embodiment is used, it is advantageous for uniformizing the light as compared with the case where the light is diffused in the light guide plate and then the wavelength is converted.

The wavelength conversion member 22 is typically a member in which particles of a phosphor are dispersed in a resin. Resins that disperse particles such as phosphors include silicone resin, modified silicone resin, epoxy resin, modified epoxy resin, urea resin, phenol resin, acrylic resin, urethane resin or fluororesin, or two or more of these resins. A resin containing the above can be used. From the viewpoint of efficiently introducing light into the light guide plate 10, it is beneficial that the base material of the wavelength conversion member 22 has a lower refractive index than the material of the light guide plate 10. The wavelength conversion member 22 may be provided with a light diffusion function by dispersing a material having a refractive index different from that of the base material in the material of the wavelength conversion member 22. For example, particles such as titanium dioxide and silicon oxide may be dispersed in the base material of the wavelength conversion member 22.

Known materials can be applied to the phosphor. Examples of the fluorescent substance are a fluoride-based fluorescent substance such as a KSF-based fluorescent substance, a nitride-based fluorescent substance such as CASN, a YAG-based fluorescent substance, a β-sialon fluorescent substance, and the like. The YAG-based phosphor is an example of a wavelength-converting substance that converts blue light into yellow light, and the KSF-based phosphor and CASN are examples of wavelength-converting substances that convert blue light into red light. Is an example of a wavelength converting substance that converts blue light into green light. The phosphor may be a quantum dot phosphor.

It is not essential that the phosphor contained in the wavelength conversion member 22 is common in the plurality of light emitting modules 201. It is also possible to make the phosphor dispersed in the base material of the wavelength conversion member 22 different among the plurality of light emitting modules 201.

The joining member 23 is a translucent member that covers at least a part of the side surface 21s of the light emitting element 21 and a part of the surface of the wavelength conversion member 22 facing the light emitting element 21, and the wavelength conversion member 22 and the light emitting element 21. And join. Although not shown in FIG. 5A, the bonding member 23 may also be located between the light emitting element 21 and the wavelength conversion member 22.

As the material of the joining member 23, a resin composition containing a transparent resin material as a base material can be used. The joining member 23 has, for example, a transmittance of 60% or more with respect to the light having the emission peak wavelength of the light emitting element 21. From the viewpoint of effective use of light, it is beneficial that the transmittance of the bonding member 23 at the emission peak wavelength of the light emitting element 21 is 70% or more, and it is more beneficial if the transmittance is 80% or more.

A typical example of the base material of the joining member 23 is a thermosetting resin such as an epoxy resin or a silicone resin. As the base material of the joining member 23, a silicone resin, a silicone-modified resin, an epoxy resin, a phenol resin, a polycarbonate resin, an acrylic resin, a polymethylpentene resin or a polynorbornene resin, or a material containing two or more of these may be used. good. The joining member 23 typically has a refractive index lower than that of the light guide plate 10. The joining member 23 may have a light diffusing function, for example, by dispersing a material having a refractive index different from that of the base material.

As described above, the joining member 23 covers at least a part of the side surface 21s of the light emitting element 21. Further, the joining member 23 has an outer surface 23c which is an interface with the light reflecting member 24 described later. The light emitted from the side surface 21s of the light emitting element 21 and incident on the joining member 23 is reflected upward at the position of the outer surface 23c of the joining member 23 toward the upper side of the light emitting element 21. The shape of the outer surface 23c of the joining member 23 in a cross-sectional view is not limited to a linear shape as shown in FIG. It may be curved or the like.

The light reflecting member 24 has light reflecting property and is arranged so as to cover the light emitting element 21 and the joining member 23. The light reflecting member 24 is also located on the surface of the light emitting element 21 where the electrode 21t is provided, and the lower surface 21ta of the electrode 21t is exposed from the light reflecting member 24. As the material of the light reflecting member 24, for example, the same material as the material of the light reflecting layer 30 can be used, and for example, the material of the light reflecting member 24 and the material of the light reflecting layer 30 may be common. .. By covering the region of the lower surface 21ma of the main body 21m excluding the electrode 21t with the light reflecting member 24, it is possible to suppress light leakage to the first main surface 10a side of the light guide plate 10.

In the light source 20, for example, a plurality of light emitting elements 21 are two-dimensionally arranged on a sheet-shaped wavelength conversion member 22 by a bonding member 23, and after bonding, the light reflecting member 24 fills the space between the plurality of light emitting elements 21 and becomes a single piece. Can be obtained by doing.

The configuration of the light source applied to the light emitting unit 101 is not limited to the example shown in FIG. 5A, and various configurations can be applied in place of the above-mentioned light source 20. Hereinafter, other examples of the light source applicable to the light emitting unit 101 will be described. Each of the light sources exemplified below has a first surface 20a and a second surface 20b located on the opposite side of the first surface 20a. In each example described below, the electrode of the light source is located on the first surface 20a side as the lower surface of the light source. The second surface 20b is the upper surface of the light source.

The light source 20B shown in FIG. 5B is an example in which the above-mentioned light emitting element 21 is applied to the light source. As described with reference to FIG. 5A, the light emitting element 21 as the light source 20B has a main body portion 21m including a semiconductor laminated structure and a first surface 20a side located on the opposite side of the emission surface 21b (see FIG. 5A). It has a pair of electrodes 21t provided on the. In this example, the lower surface 21ma of the main body 21m (see FIG. 5A) corresponds to the first surface 20a of the light source 20B, and the emission surface 21b of the light emitting element 21 corresponds to the second surface 20b of the light source 20B. In this example, the side surface 21s of the light emitting element 21 constitutes the side surface of the light source 20B.

The emission peak wavelength of the light source 20B can be adjusted by the material of the semiconductor laminate included in the semiconductor laminate structure and the crystal mixture degree thereof. For example, by using GaAs, GaP, InP, or the like as the material of the semiconductor laminate, a light source that emits red light can be obtained. The shape of the main body 21m of the light emitting element 21 can also be appropriately selected according to the application of the light emitting module 201 and the like. For example, the shape of the main body portion 21 m in a plan view can be a rectangular shape such as a square or a rectangle. Alternatively, it may be a polygon such as a triangle or a hexagon. The height of the light source 20B can be, for example, 5 μm to 300 μm. The thickness of the electrode 21t can be, for example, 0.5 μm to 100 μm. As the material of the electrode 21t, Cu, Au, Ni or the like can be used.

Similar to the example described with reference to FIG. 5A, the light source applied to the light emitting unit 101 may include a member covering the light emitting element 21 in addition to the light emitting element 21. The light source 20C shown in FIG. 5C has a light emitting element 21 and a light adjusting member 27 located on the emission surface 21b of the light emitting element 21. The light adjusting member 27 may be, for example, a resin layer formed of a material containing a transparent resin as a base material and containing a light-reflecting filler.

By arranging the light adjusting member 27 above the light emitting element 21, the amount of light emitted from the second surface 20b in the substantially normal direction among the light taken out from the light source can be adjusted. As a result, for example, it is more effective to suppress that the brightness of the region directly above the light source on the second main surface 210b of the light guide plate 210, which is the light extraction surface of the light emitting module 201, becomes extremely high as compared with other regions. obtain. That is, it is possible to provide a light emitting module 201 that suppresses luminance unevenness on the light emitting surface of the light emitting module 201 and emits light having excellent uniformity. The light adjusting member 27 may contain a material having a refractive index different from that of the base material. In this case, the light adjusting member 27 functions as a light diffusion layer. The light adjusting member 27 may contain particles of a phosphor or the like.

In the example shown in FIG. 5C, the point that the lower surface 21ma of the main body 21m of the light emitting element 21 corresponds to the first surface 20a of the light source 20C is the same as the example described with reference to FIG. 5B. On the other hand, in this example, the upper surface of the light adjusting member 27 constitutes the second surface 20b of the light source 20C. In this example, the side surface 20s of the light source 20C includes the side surface 21s of the light emitting element 21 and the side surface 27s of the light adjusting member 27.

FIG. 5D shows a light source 20D having a light emitting element 21 and a translucent member 25D. As shown in FIG. 5D, the translucent member 25D covers the side surface 21s in addition to the emission surface 21b which is the upper surface of the light emitting element 21. As described above, the light source applied to the light emitting unit 101 may have a member that also covers the side surface 21s of the light emitting element 21. Here, the lower surface and the upper surface of the translucent member 25D constitute the first surface 20a and the second surface 20b of the light source 20D, respectively. Further, here, the side surface of the translucent member 25D corresponds to the side surface 20s of the light source 20D. In the configuration exemplified in FIG. 5D, the electrode 21t of the light emitting element 21 protrudes from the translucent member 25D.

The translucent member 25D has translucency by being formed from the same material as the above-mentioned joining member 23, for example. By covering the side surface 21s in addition to the upper surface of the light emitting element 21 with the translucent member 25D, the light emitted from the side surface 21s of the light emitting element 21 can be easily taken out from the side surface 20s of the light source 20D. By connecting the light source 20D to the light guide plate 10 so that at least a part of the translucent member 25D of the light source 20D having such a structure is located inside the first recess 11 of the light guide plate 10, the first recess 11 Light can be easily introduced into the light guide plate 10 from a surface other than the surface of the surface defining the shape, which faces the second surface 20b of the light source 20D. The translucent member 25D may be imparted with a function of light diffusion, for example, by containing a material having a refractive index different from that of the base material. The translucent member 25D may contain a wavelength conversion member such as particles of a phosphor.

FIG. 5E shows an example of the configuration of the light source further including the light adjusting member 27, and FIG. 5F shows an example of the configuration of the light source further including the light reflecting member 24F. The light source 20E shown in FIG. 5E includes a layered light adjusting member 27 located on the upper surface 25b of the translucent member 25D. In this example, the upper surface of the light adjusting member 27 corresponds to the second surface 20b of the light source 20E. The side surface 20s of the light source 20E includes a side surface 27s of the light adjusting member 27 and a side surface 25s of the translucent member 25D.

Similar to the light source 20D shown in FIG. 5D, in the example shown in FIG. 5E, the electrode 21t of the light emitting element 21 protrudes from the translucent member 25D, and the lower surface 21ma of the main body portion 21m of the light emitting element 21 is also transparent. It is exposed from the optical member 25D. In such a configuration, it is preferable that the thickness of the electrode 21t of the light emitting element 21 is small. This is because the thickness of the light source (that is, the distance from the lower surface 21ta of the electrode 21t to the second surface 20b of the light source) can be reduced, and as a result, the light emitting module 201 can be made thinner.

The light source 20F shown in FIG. 5F includes a light reflecting member 24F that covers the lower surface 25a side of the translucent member 25D. In the configuration exemplified in FIG. 5F, the lower surface 21ta of the electrode 21t is aligned with the lower surface of the light reflecting member 24F and is exposed from the light reflecting member 24F. The light reflecting member 24F is formed of, for example, a resin material in which a light reflecting filler is dispersed, and has light reflecting property. A light reflecting member 24F is provided on the lower surface 25a side of the translucent member 25D, and the lower surface 21ma of the main body 21m of the light emitting element 21 and the side surface of the electrode 21t are covered with the light reflecting member 24F to guide the light emitting element 21. It is possible to suppress light leakage to the first main surface 10a side of the light plate 10. That is, it is possible to avoid absorption by a wiring board or the like that may be arranged on the first main surface 10a side of the light guide plate 10 and improve the light utilization efficiency. In this example, the lower surface of the light reflecting member 24F corresponds to the first surface 20a of the light source 20F, and the side surface 20s of the light source 20F includes the side surface 25s of the translucent member 25D and the side surface 24s of the light reflecting member 24F. There is.

As illustrated in FIG. 5G, the light source may include both the light adjusting member 27 and the light reflecting member 24F. The light source 20G shown in FIG. 5G includes a light adjusting member 27 located on the upper surface 25b of the translucent member 25D as compared with the light source 20F shown in FIG. 5F. Therefore, the side surface 20s of the light source 20G includes the side surface 27s of the light adjusting member 27 in addition to the side surface 25s of the translucent member 25D and the side surface 24s of the light reflecting member 24F.

The light source 20H shown in FIG. 5H is an example of a configuration in which the translucent member 25H is provided in place of the translucent member 25D of the example described with reference to FIG. 5G. As shown in FIG. 5H, the translucent member 25H has a two-layer structure of the first translucent member 251 and the second translucent member 252. The first translucent member 251 covers the exit surface 21b and the side surface 21s of the light emitting element 21 in the same manner as the above-mentioned translucent member 25D, and the second translucent member 252 is the first translucent member 251. It is located on the upper surface 251b. That is, the second translucent member 252 is interposed between the first translucent member 251 and the light adjusting member 27. In this example, the side surface 20s of the light source 50H is the side surface 24s of the light reflecting member 24F, the side surface 27s of the light adjusting member 27, the side surface of the translucent member 25H, that is, the side surface 251s of the first translucent member 251. Includes the side surface 252s of the second translucent member 252.

As shown in FIG. 5I, it is not essential that a part of the translucent member (for example, the translucent member 25D) is interposed between the emission surface 21b of the light emitting element 21 and the light adjusting member 27. .. Compared to the light source 20G shown in FIG. 5G, the light source 20I shown in FIG. 5I has a translucent member 25I instead of the translucent member 25D. As shown in FIG. 5I, the translucent member 25I covers the side surface 21s of the light emitting element 21, but is not located on the emission surface 21b. In the example shown in FIG. 5I, the upper surface 25b of the translucent member 25I is aligned with the emission surface 21b of the light emitting element 21, and the light adjusting member 27 is formed so as to collectively cover these surfaces. .. The light adjusting member 27 may be in direct contact with the emission surface 21b of the light emitting element 21. The translucent member 25I may be imparted with a function of light diffusion, for example, by containing a material having a refractive index different from that of the base material. The translucent member 25I may contain a wavelength conversion member such as particles of a phosphor.

The light source 20J shown in FIG. 5J generally has a structure in which the wavelength conversion member 22 of the light source 20 described with reference to FIG. 5A is replaced with a plate-shaped translucent member 25J. In this example, the upper surface 24b of the light reflecting member 24 is aligned with the exit surface 21b of the light emitting element 21 and the upper surface 23b of the joining member 23, and the translucent member 25J is the light emitting element 21, the joining member 23 and the light reflection. It is located above the top surface of these members across the members 24. In this example, the lower surface of the light reflecting member 24 and the upper surface of the translucent member 25J correspond to the first surface 20a and the second surface 20b of the light source 20J, respectively. The side surface 20s of the light source 20J includes a side surface 25s of the translucent member 25J and a side surface 24s of the light reflecting member 24.

In the configuration exemplified in FIG. 5J, the emission surface 21b of the light emitting element 21 and the upper surface 23b of the joining member 23 are exposed from the light reflecting member 24 provided so as to surround the light emitting element 21. According to such a configuration, the light from the light emitting element 21 can be concentrated upward, and the light distribution in the light source 20J can be easily controlled by the translucent member 25J. Also in the configuration exemplified in FIG. 5A, since the light reflecting member 24 is provided so as to surround the light emitting element 21, the same effect can be expected.

The light source 20K shown in FIG. 5K has a configuration in which the light adjusting member 27 is further arranged on the upper surface 25b of the translucent member 25J of the light source 20J shown in FIG. 5J. Therefore, in this example, the side surface 20s of the light source 20K includes the side surface 27s of the light adjusting member 27 in addition to the side surface 25s of the translucent member 25J and the side surface 24s of the light reflecting member 24.

The light source 20L shown in FIG. 5L has a configuration in which the translucent member 25J of the light source 20K shown in FIG. 5K is replaced with the translucent member 25L. Similar to the example described with reference to FIG. 5H, the translucent member 25L has a two-layer structure of the first translucent member 251 and the second translucent member 252. However, here, the shape of the first translucent member 251 is a plate shape. The point that the side surface 20s includes the side surface 24s of the light reflecting member 24, the side surface 27s of the light adjusting member 27, the side surface 251s of the first translucent member 251 and the side surface 252s of the second translucent member 252 is a point. It is almost the same as the light source 20H shown in FIG. 5H.

The light source 20M shown in FIG. 5M has a translucent member 25M instead of the translucent member 25L as compared with the light source 20L shown in FIG. 5L. The translucent member 25M is a member in which the arrangements of the first translucent member 251 and the second translucent member 252 of the translucent member 25L are interchanged with each other. That is, in this example, the first translucent member 251 is located on the upper surface 252b of the second translucent member 252.

As described above, the arrangement of the first translucent member 251 and the second translucent member 252 in the light source is such that the first translucent member 251 is closer to the light emitting element 21 than the second translucent member 252. It is not limited to the arrangement that is located in. A wavelength conversion substance such as a phosphor may be selectively dispersed in either the first translucent member 251 or the second translucent member 252. For example, the first translucent member 241 may be a layer containing a wavelength converting substance, and the second translucent member 242 may be a layer containing substantially no wavelength converting substance.

Alternatively, each of the first translucent member 251 and the second translucent member 252 may contain a wavelength conversion substance. However, in this case, the wavelength conversion substances may be different from each other between the first translucent member 251 and the second translucent member 252, or the concentration of the wavelength conversion substance between these members while sharing the wavelength conversion substance. May be different from each other. The translucent member in the light source may have a laminated structure of three or more layers. As in the example shown in FIG. 5H, when the light emitting element 21 has a shape that covers the emission surface 21b and the side surface 21s, the translucent member is, for example, a portion that covers the emission surface 21b of the light emitting element 21. It may include two portions (for example, a plate-shaped portion) and a portion (for example, an annular portion) that covers the side surface 21s of the light emitting element 21. When the translucent member has a portion covering the emission surface 21b of the light emitting element 21 and a portion covering the side surface 21s of the light emitting element 21, these portions may be formed from the same material. Alternatively, for example, the type and / or concentration of the wavelength converting substance to be dispersed may be different between these two parts.

The light source 20N shown in FIG. 5N has a light reflecting member 24N. The light reflecting member 24N directly or indirectly covers the side surface 21s of the light emitting element 21 like the light reflecting member 24 of the light source 20J shown in FIG. 5J. However, in this example, the light reflecting member 24N also covers the side surface 25s of the translucent member 25J. Here, "indirectly covering the side surface 21s of the light emitting element 21" means covering the side surface 21s of the light emitting element 21 via another member such as a joining member 23 located on the side surface 21s of the light emitting element 21. Point to. In the example shown in FIG. 5N, the light reflecting member 24N covers not only a part of the side surface 21s of the light emitting element 21 but also the outer surface 23c of the joining member 23.

In the configuration exemplified in FIG. 5N, the upper surface 25b of the translucent member 25J is exposed from the light reflecting member 24N and is aligned with the upper surface 24b of the light reflecting member 24N. Here, the set of the upper surface 25b of the translucent member 25J and the upper surface 24b of the light reflecting member 24 constitutes the second surface 20b of the light source 20N. With such a configuration in which the side surface 25s of the translucent member 25J is covered with the light reflecting member 24N, the light emitted from the light source 20N can be concentrated above the light emitting element 21. Therefore, for example, the light distribution can be easily controlled by the light reflecting member 40 located inside the second recess 12 on the second main surface 10b side of the light guide plate 10.

In addition to the structure shown in FIG. 5N, the light source 20O shown in FIG. 5O has a light adjusting member 27 located above the upper surface 25b of the translucent member 25J. Further, here, the second translucent member 252 is arranged between the translucent member 25J and the light adjusting member 27. The second translucent member 252 collectively covers the upper surface 25b of the translucent member 25J and the upper surface 24b of the light reflecting member 24N, and the light adjusting member 27 is on the upper surface 252b of the second translucent member 252. Located in. In this example, the translucent member 25J and the second translucent member 252 realize the translucent member 25O having these two-layer structures.

In the light source 20O, the light reflecting member 24N covers the side surface 25s of the translucent member 25J on the lower layer side of the translucent member 25O having a two-layer structure, while the second translucent member 252 on the upper layer side. The side surface 252s is not covered. By covering the side surface 25s of the translucent member 25J with the light reflecting member 24N, the light emitted from the light emitting element 21 can be concentrated above the translucent member 25J. Therefore, the light adjusting member 27 on the upper surface 252b of the second translucent member 252 can be made to function more effectively, and for example, the light distribution can be easily controlled by the light adjusting member 27.

In the example described with reference to FIGS. 5J to 5O, the translucent member (translucent member 25J, 25L or 25M) and the light emitting element 21 are bonded by the joining member 23. A part of the joining member 23 may be located between the light emitting element 21 and the translucent member. The joining member 23 may be omitted.

The light source applied to the light emitting unit 101 may include two or more light emitting elements. FIG. 5P shows an example in which the light source applied to the single light emitting unit 101 includes a plurality of light emitting elements. The light source 20P shown in FIG. 5P has a total of four light emitting elements. In FIG. 5P, an exemplary appearance of the light source 20P when viewed in the normal direction of the second surface 20b and a schematic cross section when the light source 20P is cut perpendicular to the second surface 20b are combined. It is shown in one figure.

In the configuration exemplified in FIG. 5P, the light source 20P has one light emitting element 21G, one light emitting element 21B, and two light emitting elements 21R. As shown in the upper part of FIG. 5P, these four light emitting elements have an arrangement of two columns and two rows in a plan view. In this example, the light emitting element 21R is arranged at the positions of the first row and the first column and the second row and the second column, and the light emitting element 21G is arranged at the position of the first row and the second column. Further, the light emitting element 21B is arranged at the position of the second row and the first column. In this example, the translucent member 25J is arranged above the four emission surfaces 21b so as to collectively cover these four light emitting elements, and the light adjusting member 27 is further placed on the upper surface 25b of the translucent member 25J. Is placed. Further, the light source 20P further has a light reflecting member 24P that covers the side surface 21s of each light emitting element.

The light emitting element 21G is, for example, an LED that emits green light, and the light emitting element 21B is, for example, an LED that emits blue light. The light emitting element 21R is, for example, an LED that emits red light. When a plurality of light emitting elements having different emission peak wavelengths are arranged in a single light source to obtain the three primary colors of light as in this example, the wavelength conversion substance is not dispersed in the translucent member 25J. For example, it is possible to obtain white light. Of course, the number of light emitting elements 21 in a single light source is not limited to four. When the light source includes a plurality of light emitting elements, the light emitting wavelengths may be different among these light emitting elements, or the light emitting wavelengths may be common among these light emitting elements.

As an example described with reference to FIGS. 5A, 5F to 5I, and 5J to 5P, a light reflecting member (light reflecting member 24) covering the lower surface 21ma of the main body 21m of the light emitting element 21 and the side surface of the electrode 21t. , 24F or 24P), a wiring layer connected to the electrode 21t of the light emitting element 21 may be formed on the first surface 20a of the light source. The wiring layer on the first surface 20a is, for example, a part of the wiring layer 60 described above, and can be obtained by patterning a metal film formed by plating, sputtering, or the like. The metal film may be a single-layer film made of a material such as Ag, Ni, Au, Ru, Ti, Pt, or a laminated film. The wiring layer on the first surface 20a includes, for example, a laminated film in which Ag and Cu are sequentially deposited, a laminated film in which Ni and Au are sequentially deposited, a laminated film in which Ni, Ru and Au are sequentially deposited, and Ti, Pt and Au. It may be formed in the form of a laminated film in which Cu, Ni and Au are deposited in order, or a laminated film in which Cu, Ni and Au are deposited in order.

Any of the above-mentioned light sources 20C to 20P can be prepared by integrating the light emitting element 21 with other members such as a light adjusting member, a translucent member, and a light reflecting member. Alternatively, the light source applied to the light emitting module 201, or all or part of the members constituting the light source, may be prepared by purchase.

[Translucent members 50A, 50B]
6A and 6B are sectional views showing an enlarged view of the vicinity of the first recess 11 of the first light emitting unit 101A. FIG. 6A schematically shows a YZ cross section of the first light emitting unit 101A, and FIG. 6B schematically shows a ZX cross section of the first light emitting unit 101A. 6C and 6D are sectional views showing an enlarged view of the vicinity of the first recess 11 of the second light emitting unit 101B. 6A to 6D show the first light emitting unit 101A and the second light emitting unit with the top and bottom reversed from FIGS. 3A and 4A so that the bottom of the first recess 11 is located on the lower side for the sake of clarity. 101B is illustrated.

As shown in FIGS. 6A to 6D, the light source 20 is arranged in the first recess 11 of the light emitting unit 101, and the translucent member 50 covers at least a part of the side surface 20s of the light source 20 in the first recess 11. Placed inside. A translucent member 50A is formed in the first recess 11 of the first light emitting unit 101A, and a translucent member 50B is formed in the first recess 11 of the second light emitting unit 101B. In the following, the light source 20 shown in FIG. 5A is exemplified as the light source applied to the light emitting unit 101, but other examples described with reference to FIGS. 5B to 5P can be applied instead of the light source 20. Needless to say.

More specifically, the second surface 20b of the light source 20 (here, the main surface 22a of the wavelength conversion member 22 which is the light extraction surface and is not joined to the light emitting element 21) faces the bottom surface 11b of the first recess 11. As such, the light source 20 is arranged in the first recess 11. The translucent members 50A and 50B cover at least a part of the light source 20 and are arranged in a space not occupied by the light source 20 in the first recess 11.

See FIGS. 6A and 6B. As shown in FIGS. 6A and 6B, in the first light emitting unit 101A, the upper surface 50Aa of the translucent member 50A has a first recess 51A recessed on the bottom surface 11b side of the first recess 11. Here, whether or not the upper surface 50Aa has the first recess 51A is determined by, for example, the point 51A1 of the upper surface 50Aa in contact with the inner side surface of the first recess 11 and the point in contact with the side surface 20s of the light source 20. It can be determined whether or not the upper surface 50Aa is recessed toward the bottom surface 11b with reference to the straight line connecting the 51A2 (shown by a broken line in FIG. 6B). The first recess 51A may be arranged along the four sides of the rectangular shape of the light source 20 so as to surround the light source 20 in a plan view.

In the configurations illustrated in FIGS. 6A and 6B, the translucent member 50A is in contact with the entire inner surface of the first recess 11 and the entire side surface 20s of the light source 20. Therefore, the points 51A1 and 51A2 are located at the highest position on the inner surface of the first recess 11 and the highest position on the side surface 20s of the light source 20, respectively. However, as shown in FIG. 6E, the points 51A1 and 51A2 may be located in the middle of the inner side surface and the side surface 20s in the height direction, respectively. The translucent member 50A may be in contact with a part of the inner side surface of the first recess 11 and a part of the side surface 20s of the light source 20. This also applies to the second light emitting unit 101B, even if the translucent member 50B is in contact with a part of the inner surface of the first recess 11 and a part of the side surface 20s of the light source 20. good.

The light source 20 is fixed to the inside of the first recess 11 by the translucent member 50A. As shown in FIG. 6A, in this example, the light source 20 of the first light emitting unit 101A has an optical axis of + Y with respect to the center of the first recess 11 provided on the first main surface 10a of the light guide plate 10. It is arranged in the first recess 11 so as to be displaced in the direction. That is, as can be understood from the comparison between FIGS. 6A and 6C, for example, in the present embodiment, the optical axis of the light source 20 of the first light emitting unit 101A is deviated from the center of the first recess 11. In this example, in the ZX cross section of the first light emitting unit 101A, the optical axis of the light source 20 coincides with the center of the first recess 11 (see FIG. 6B).

Here, the optical axis of the light source 20 is an axis perpendicular to the emission surface 21b which is the upper surface of the light emitting element 21 and passing through the center of the emission surface 21b of the light emitting element 21 in a plan view, or a plane perpendicular to the upper surface of the light source 20. It refers to an axis passing through the center of the upper surface of the light source 20 in the visual sense. In the example shown in FIG. 5A, the upper surface 22b of the wavelength conversion member 22 constitutes the upper surface of the light source 20.

As shown in FIGS. 6A and 6B, here, the shape of the upper surface 50Aa of the translucent member 50A is substantially symmetrical with respect to the light source 20 in the ZX cross section, whereas the upper surface 50Aa of the translucent member 50A in the YZ cross section is shown here. The shape of is asymmetric with respect to the light source 20. By differently arranging the light source 20 with respect to the center of the first recess 11 between two different cross sections perpendicular to the first main surface 10a of the light guide plate 10, two different directions (in this example, the X direction and the X direction). With respect to the Y direction), it is possible to intentionally make a difference in the geometric shape of the upper surface 50Aa of the translucent member 50A.

As shown in FIGS. 6A and 6B, the upper surface 50Aa of the translucent member 50A is covered with the light reflecting layer 30. Therefore, anisotropy occurs in the geometric shape of the upper surface 50Aa of the translucent member 50A between the X direction and the Y direction, so that the translucent member on the first main surface 10a side of the light guide plate 10 In-plane anisotropy occurs in the reflection characteristics of 50A. That is, by arranging the light source 20 in the first recess 11 so that the optical axis deviates from the center of the first recess 11, the light source 20 is arranged in the XY plane between two different directions (for example, the X direction and the Y direction). It is possible to obtain different light distribution characteristics.

In the examples shown in FIGS. 6A and 6B, the first recess 51A is formed along the four sides of the rectangular shape of the light source 20 so as to surround the light source 20 in a plan view. However, the shape of the upper surface 50Aa of the translucent member 50A is not limited to this example. As shown in FIG. 6F, for example, the upper surface 50Aa may have different shapes on both sides of the light source 20 in a cross-sectional view. In the example shown in FIG. 6F, the upper surface 50Aa has the first recess 51A on the negative side in the Y direction with respect to the light source 20. On the other hand, the shape of the upper surface 50Aa on the positive side in the Y direction with respect to the light source 20 is linear in a cross-sectional view. In this example, a part of the translucent member 50A is located on the first main surface 10a of the light guide plate 10 on the positive side in the Y direction with respect to the light source 20. The translucent member 50 may be selectively formed inside the first recess 11, or a part thereof is located on the first main surface 10a of the light guide plate 10 as in this example. May be good.

On the other hand, as shown in FIGS. 6C and 6D, in the second light emitting unit 101B, the light source 20 is arranged in the first recess 11 so that its optical axis substantially coincides with the center of the first recess 11. To. Therefore, in this example, the shape of the upper surface 50Ba of the translucent member 50B is substantially symmetrical with respect to the light source 20 in both the YZ cross section and the ZX cross section. The point that the upper surface 50Ba of the translucent member 50B is covered with the light reflecting layer 30 is the same as that of the first light emitting unit 101A. Further, here, the center of the first recess 11 and the center of the second recess 12 in a plan view are aligned with each other. Therefore, here, in the second light emitting unit 101B, the optical axis of the light source 20 also coincides with the center of the second recess 12 which is a lens structure. That is, in the second light emitting unit 101B, there is no significant difference in the light distribution characteristics between the X direction and the Y direction.

In this way, by making the arrangement of the light source 20 in the first recess 11 different between the first light emitting unit 101A and the second light emitting unit 101B, the light distribution of the light emitted from the first unit region 211A can be obtained. , The light distribution of the light emitted from the second unit region 211B can be different from each other. In the configurations illustrated in FIGS. 6C and 6D, the upper surface 50Ba of the translucent member 50B does not have a recess and is linear in cross-sectional view. This also brings about a difference in light distribution between the first unit region 211A and the second unit region 211B.

Further, in the present embodiment, among the plurality of light emitting units 101, for the first light emitting unit 101A, the light source 20 is arranged in the first recess 11 so that the optical axis of the light source 20 is deviated from the center of the first recess 11. is doing. For example, by arranging the light source 20 biased to the positive side or the negative side in a certain direction so as to "shift" in the direction in the first concave portion 11 of the first light emitting unit 101A, a single first light emitting unit 101A It is possible to realize an asymmetric light distribution with respect to the center of the first recess 11 along the direction thereof. According to the embodiment of the present disclosure, when looking at a single first light emitting unit 101A, the light guide plate 10 is directed from the first main surface 10a to the second main surface 10b as compared with the negative side in the Y direction, for example. It is possible to increase the proportion of light on the positive side in the Y direction.

The translucent members 50A and 50B are formed from a resin composition containing a transparent resin material as a base material, similarly to the joining member 23. The material of the translucent member 50 may be different from the material of the joining member 23, or may be common. The translucent member 50 typically has a refractive index lower than that of the light guide plate 10.

As described below, the shapes of the translucent member 50A of the first light emitting unit 101A and the translucent member 50B of the second light emitting unit 101B are, for example, in consideration of the reduction in volume due to curing. It can be controlled by adjusting the position of the light source 20 arranged in the recess 11 and the amount of the uncured material of the translucent members 50A and 50B arranged in the first recess 11.

[Intermediate through holes 15A, 15B]
In the configurations illustrated in FIGS. 6A to 6F, the first recess 11 and the second recess 12 provided in the light guide plate 10 of each light emitting unit 101 are spatially separated from each other by the material of the light guide plate 10. Has been done. In other words, in these examples, the light guide plate 10 of each light emitting unit 101 does not have a structure that penetrates from the first main surface 210a to the second main surface 210b of the light guide plate 210. However, the plurality of light emitting units 101 may include a light emitting unit having a structure as a part thereof that penetrates from the first main surface 210a to the second main surface 210b of the light guide plate 210.

FIG. 6G shows another example of the structure of the light guide plate 10 of the first light emitting unit 101A, and FIG. 6H shows another example of the structure of the second light emitting unit 101B. Here, both the cross section of the first light emitting unit 101A and the cross section of the second light emitting unit 101B are shown as representatives of the YZ cross section.

In the configuration exemplified in FIG. 6G, the light guide plate 10 of the first light emitting unit 101A has an intermediate through hole 15A connecting the first recess 11 and the second recess 12. As schematically shown in FIG. 6G, the intermediate through hole 15A extends from the bottom surface 11b of the first recess 11 to the side surface defining the conical shape of the first portion 12c of the second recess 12. The space inside the 1 recess 11 communicates with the space inside the second recess 12 by an intermediate through hole 15A. Similarly, in the configuration exemplified in FIG. 6H, the light guide plate 10 of the second light emitting unit 101B has an intermediate through hole 15B extending from the first recess 11 to the second recess 12.

In the examples shown in FIGS. 6G and 6H, the intermediate through holes 15A and 15B are located near the center of the light guide plate 10. The positions where the intermediate through holes 15A and 15B are provided may be any positions where the first recess 11 and the second recess 12 overlap in a plan view. The size of the intermediate through hole 15A and the size of the intermediate through hole 15B in a plan view are the first of the corresponding first recess 11, the opening 11a located on the first main surface 10a, and the corresponding second recess 12. 2 Smaller than the opening located on the main surface 10b. The center of the intermediate through hole 15A and / or 15B may be approximately aligned with the deepest portion of the first recess 11 or the deepest portion of the second recess 12. The intermediate through holes 15A and 15B can be used, for example, as alignment marks when arranging a light source (here, the light source 20) in the first recess 11.

The intermediate through holes 15A and 15B have, for example, a cylindrical shape. Of course, the shapes of the intermediate through holes 15A and 15B are not limited to this example. For example, the inner side surface defining the shapes of the intermediate through holes 15A and 15B may be inclined from the normal direction of the first main surface 10a in a cross-sectional view. The inner side surface that defines the shape of the intermediate through holes 15A and 15B is not limited to a linear shape in a cross-sectional view, and may have a shape including a curved portion, a bend, a step, or the like.

The inside of the intermediate through hole 15A may be hollow, or a part or all of the inside thereof may be filled with, for example, a translucent material. Similarly, it is not essential that the inside of the intermediate through hole 15B is hollow. For example, the material of the translucent member 50 or the material of the light reflective member 40 may be located in a part of the inside of the intermediate through hole 15A and / or the intermediate through hole 15B.

The intermediate through hole 15A may be formed in all the light guide plates 10 of at least one first light emitting unit 101A included in the light emitting module 201, or may be formed in all the light guide plates 10 of at least one first light emitting unit 101A, or may be formed as a guide for a part of at least one first light emitting unit 101A. It may be formed on the light plate 10. Similarly, it is not essential that the intermediate through holes 15B are formed in all the light guide plates 10 of the plurality of second light emitting units 101B included in the light emitting module 201. An intermediate through hole 15B may be selectively provided in a part of the light guide plate 10 among the plurality of second light emitting units 101B.

(Manufacturing method of light emitting module 201)
The light emitting module 201 can be manufactured, for example, by the following method. First, a light guide plate 210 in which the first recess 11 and the second recess 12 are formed in each unit region 211 is prepared (see FIGS. 2A to 2C). At this time, for example, a mold is used in which a cavity is formed so that the center of the first recess 11 and the center of the second recess 12 coincide with each other. The position and number of the first light emitting unit 101A or the second light emitting unit 101B can be arbitrarily determined by the shape of the cavity of the mold. In the inside of the cavity, one of the convex portion corresponding to the shape of the first concave portion 11 and the convex portion corresponding to the shape of the second concave portion 12 is provided with a portion that contacts the other, or the first concave portion is provided. Intermediate through holes 15A and 15B are formed by forming a hole that penetrates from one of the first recess 11 and the second recess 12 to the other after obtaining the shape of the light guide plate having the 11 and the second recess 12. It is possible to obtain the shape of the light guide plate 10 having the above.

Next, the uncured materials of the translucent members 50A and 50B are arranged in the first recess 11 of the light guide plate 10 by using a dispenser or the like. At this time, the amount of the uncured material of the translucent member arranged in the first recess 11 of the first unit region 211A to be the first light emitting unit 101A and the second unit region 211B to be the second light emitting unit 101B. 1 The amount of uncured material of the translucent member arranged in the recess 11 may be different. For example, in the first recess 11 of the first unit region 211A, the second unit region is formed so that the first recess 51A is formed on the upper surface 50Aa of the translucent member 50A when the light source 20 is arranged and cured. A smaller amount of uncured material may be placed as compared to the first recess 11 of 211B.

After that, the light source 20 is arranged in the first recess 11 to cure the uncured material of the translucent member. At this time, the arrangement of the light source 20 in the first recess 11 is different between the first unit region 211A and the second unit region 211B. Specifically, the light source 20 is arranged in the first recess 11 of the second unit region 211B, which is the second light emitting unit 101B, so that the center of the first recess 11 and the optical axis of the light source 20 substantially coincide with each other. do. On the other hand, in the first recess 11 of the first unit region 211A to be the first light emitting unit 101A, for example, the optical axis of the light source 20 is shifted along a certain direction (for example, the Y direction) with respect to the center of the first recess 11. As a result, the light source 20 is arranged at the center of the first recess 11 so that the optical axes of the light source 20 do not match. For example, here, the light source 20 is arranged in the first recess 11 of the first unit region 211A by shifting the optical axis of the light source 20 to the positive side in the Y direction with respect to the center of the first recess 11.

A translucent member obtained by curing an uncured material by arranging the light source 20 in the first recess 11 by shifting the optical axis of the light source 20 to the positive side in the Y direction with respect to the center of the first recess 11. The geometric shape of the upper surface 50Aa of 50A can be asymmetric with respect to the light source 20. The position and number of the first light emitting unit 101A or the second light emitting unit 101B can be arbitrarily determined by adjusting the position of the light source 20 arranged in the first recess 11. The number of the first unit regions 211A included in the light guide plate 210 of one light emitting module 201 may be one or a plurality. The plurality of unit areas 211 may have at least one first unit area 211A. When the plurality of unit regions 211 include the plurality of first unit regions 211A, it is not essential that all the first unit regions 211A are continuously arranged in one light guide plate 210.

Next, a resin material or the like in which a light-reflecting filler is dispersed is applied to the first main surface 10a side of the light guide plate 10 to cure the resin material. Further, the light-reflecting resin layer obtained by curing the resin material is polished until the electrode 21t of the light source 20 is exposed. As a result, the light reflecting layer 30 that covers the first main surface 10a of the light guide plate 10 can be formed.

After that, the wiring layer 60 is formed on the light reflecting layer 30. Further, a light reflecting member 40 is formed in the second concave portion 12 on the second main surface of the light guide plate 210 by, for example, an inkjet method or the like. This completes the light emitting module 201 including the first light emitting unit 101A and the second light emitting unit 101B.

(Light distribution characteristics of the first light emitting unit 101A and the second light emitting unit 101B)
Here, the light distribution characteristics of the first light emitting unit 101A and the second light emitting unit 101B and their differences will be described with reference to FIGS. 7A and 7B. In both the first light emitting unit 101A and the second light emitting unit 101B, the light emitted from the light source 20 is directed to the second main surface 10b of the light guide plate. A second concave portion 12 is formed on the second main surface 10b, and a part of the light directed to the second main surface 10b is first main due to the light reflecting member 40 formed in the second concave portion 12. It is reflected on the surface 10a side. The light directed to the first main surface 10a is reflected by the light reflecting layer 30 and is directed to the second main surface 10b side again.

Since the light reflecting layer 30 forms an interface with the translucent members 50A and 50B and the light guide plate 10, and the translucent members 50A and 50B are adjacent to the light emitting element 21, the translucent members 50A and 50B The reflection at the interface with the light emitting unit 101A affects the light distribution characteristics of the first light emitting unit 101A and the second light emitting unit 101B.

As described above, here, the light source 20 is arranged in the first recess 11 of the first light emitting unit 101A so as to be biased to the positive side in the Y direction in the figure. Therefore, in the cross section shown in FIG. 7A, the portion of the upper surface 50Aa of the translucent member 50A defining the first recess 51A located on the positive side in the Y direction with respect to the light source 20 is located on the negative side in the Y direction. It forms a curved surface with a larger curvature than the portion. Therefore, different reflection characteristics with respect to the light from the light source 20 can be obtained between the portion of the upper surface 50Aa of the translucent member 50A located on the left side and the portion located on the right side of the light source 20 in FIG. 7A. Specifically, as schematically shown in FIG. 7A, the light emitted to the negative side in the Y direction is likely to be reflected toward the outer edge of the light guide plate 10, but is emitted to the positive side in the Y direction. In the light emitted, more parts are reflected toward the second main surface 10b at an angle close to vertical. That is, in the first light emitting unit 101A, since the optical axis of the light source 20 is deviated from the center of the first recess 11, the light emitted from the light source 20 does not spread and is easily emitted upward.

In particular, in this example, since the optical axis of the light source 20 is deviated from the center of the first recess 11, the first recess 51A is provided on the upper surface 50Aa of the translucent member 50A. When the first recess 51A is provided, as can be seen from the comparison with the shape of the upper surface 50Ba of the translucent member 50B shown in FIG. 7B, the upper surface 50Aa of the translucent member 50A is tilted more toward the light source 20. A region is generated on the light source 20 side. Therefore, the light reflected by the upper surface 50Aa of the translucent member 50A does not spread and easily travels toward the first main surface 10a as compared with the upper surface 50Ba of the translucent member 50B having no first recess 51A. As a result, in a region where the distance between the light source 20 and the inner side surface of the first recess 11 is relatively small inside the first recess 11 of the first light emitting unit 101A, more light emitted from the light source 20 is emitted. It is possible to emit light upward.

In this example, the upper surface 50Ba of the translucent member 50B does not have a recess like the first recess 51A, so that the second light emitting unit 101B is guided as compared with the first light emitting unit 101A. It can be said that the light plate 10 has a structure that easily diffuses light in the plane. As shown in FIGS. 7A and 7B, the second light emitting unit 101B can easily obtain a wider light distribution angle than the first light emitting unit 101A. As a result, according to the present embodiment, different light distribution characteristics can be obtained between the first light emitting unit 101A and the second light emitting unit 101B, and further, the light distribution can be obtained even in a single first light emitting unit 101A. Anisotropy can be generated. As described above, according to the embodiment of the present disclosure, there is provided a light emitting module capable of partially adjusting the light distribution characteristics of the light emitting surface when viewed as a whole of a two-dimensional array of a plurality of light emitting units 101. It is possible.

(Usage form of light emitting module 201)
The light distribution characteristics of the first light emitting unit 101A and the second light emitting unit 101B are different, and the light distribution angle of the first light emitting unit 101A is typically narrower than the light distribution angle of the second light emitting unit 101B. .. Here, the "Beam Angle" refers to an angle range in which the luminous intensity is halved as compared with the one on the optical axis. Further, in the light emitting module 201, the position and the number of the first light emitting units 101A can be arbitrarily selected. By having such a feature, the light emitting module 201 can have contradictory characteristics such as versatility and light distribution characteristics according to an application. For example, the light emitting module 201 can be suitably used as a backlight of a liquid crystal display device.

8A-8C show exemplary sequences of the first light emitting unit 101A and the second light emitting unit 101B in the light emitting module. The light emitting module 201A shown in FIG. 8A includes a total of 16 unit regions 211 arranged in 4 rows and 4 columns, as in the example described with reference to FIG. 1B. In this example, by locating the four first light emitting units 101A in the first row, the four first unit regions 211A are arranged along the rectangular side of the second main surface 210b of the light guide plate 210. When paying attention to the first light emitting unit 101A of each first unit region 211A, here, the light source 20 is shown with respect to the center of the first recess 11 so that its optical axis does not coincide with the center of the first recess 11. It is "shifted" in the + Y direction of, for example, in the range of about 25 μm or more and 250 μm or less, and is arranged in the first recess 11. On the other hand, the remaining area of the 16 unit areas 211 is designated as the second unit area 211B by locating the second light emitting unit 101B. For the sake of clarity, in FIG. 8A, the position of the first unit area 211A among the plurality of unit areas 211 is shaded. This point is the same in FIGS. 8B and 8C described below.

In the light emitting module 201B shown in FIG. 8B, a total of seven first light emitting units 101A are arranged at the positions of the first row and the first column of 4 rows and 4 columns, and a total of 9 first light emitting units 101A are arranged at the remaining positions. 2 Light emitting units 101B are arranged. Here, of the four first light emitting units 101A located at the upper end of the light guide plate 210, that is, the first row of the fourth row and the fourth column, the three first light emitting units located in the second to fourth columns. In each of the 101A, the arrangement of the light source 20 is "shifted" in the + Y direction of the figure with respect to the center of the first recess 11, as in the example shown in FIG. 8A. Further, of the four first light emitting units 101A located at the left end of the light guide plate 210, that is, the first column of the fourth row and the fourth column, the three first light emitting units 101A located in the second to fourth rows. In each of the above, the arrangement of the light source 20 is "shifted" in the −X direction in the figure with respect to the center of the first recess 11.

In the example shown in FIG. 8B, the first light emitting unit 101A located at the rectangular corner of the light guide plate 210 among the seven first light emitting units 101A further has a light source 20 with respect to the center of the first recess 11. Is "shifted" to the positive side of the W direction, which forms an angle of 135 ° with respect to the X direction. In other words, in the first light emitting unit 101A located at the upper left corner of the light guide plate 210 in FIG. 8B, the light source in the first recess 11 so that the optical axis of the light source 20 is brought closer to the corner of the light guide plate 210. The arrangement of 20 has been adjusted. As described above, the direction of the "shift" of the light source 20 with respect to the center of the first recess 11 is not limited to the direction parallel to one side of the rectangular shape of the second main surface 210b of the light guide plate 210.

In the light emitting module 201C shown in FIG. 8C, a total of four first light emitting units 101A are arranged at the positions of the first column of 4 rows and 4 columns, and a total of 12 first light emitting units 101A are arranged at the positions of the 2nd to 4th columns. 2 Light emitting units 101B are arranged. Focusing on the first light emitting unit 101A of each first unit region 211A shown in FIG. 8C, here, the light source 20 “shifts” its optical axis with respect to the center of the first recess 11 in the −X direction of the figure. Has been done.

As described above, each of the light emitting modules 201A to 201C includes a plurality of light emitting units 101 arranged two-dimensionally in the row and column directions, and the first light emitting unit 101A is the outermost of the plurality of light emitting units 101. Multiple rows or columns are arranged. In this case, the plurality of unit regions 211 of the light guide plate 210 are arranged two-dimensionally in the row and column directions, and the first unit region 211A is a plurality of unit regions 211 in the outermost row or column of the plurality of unit regions 211. Be placed.

On the other hand, the light emitting module 201D shown in FIG. 8D includes only the second light emitting unit 101B. As described below, a plurality of light emitting modules 201A to 201C and light emitting modules 201D of the present embodiment are prepared, and by combining and arranging them two-dimensionally, a surface light emitting source having a larger light emitting surface is constructed. It is possible to do.

FIG. 9 shows an example of a backlight that can be configured by using the light emitting modules 201A to 201D. The backlight 301 shown in FIG. 9 is configured by arranging a plurality of light emitting modules including a unit region 211, each of which is arranged in 4 rows and 4 columns, in 8 rows and 16 columns. The light emitting surface of the backlight 301 has a rectangular shape as a whole. If the vertical length L and the horizontal length W of each light emitting module are, for example, approximately 24.3 mm and 21.5 mm, respectively, the backlight 301 has an aspect ratio of 16: 9, 15.6. Suitable for inch screen size LCD panels.

As shown in FIG. 9, the backlight 301 includes the above-mentioned light emitting modules 201A to 201D. In the backlight 301, the light emitting modules 201A to 201D are arranged so that the first light emitting unit 101A is close to the four sides SU, SD, SR, and SL that define the rectangular shape of the light emitting surface. Specifically, any of the light emitting modules 201A to 201C is located on the outermost circumference of the array of 8 rows and 16 columns of the light emitting modules, and the light emitting modules 201D are arranged at the remaining positions.

For example, the light emitting module 201B shown in FIG. 8B is located at the upper left corner of the backlight 301 (the angle between the side SU and the side SL). Similarly, in the lower left corner of the backlight 301 (the corner between the side SL and the side SD), the lower right corner (the corner between the side SD and the side SR), and the upper right corner (the corner between the side SR and the side SU). Also, the light emitting module 201B is located. However, the light emitting module 201B located at these corners is rotated by 90 °, 180 °, and 270 ° around the Z axis from the state shown in FIG. 8B, respectively. In other words, the light emitting module 201B in the backlight 301 is arranged in the direction in which the first light emitting unit 101A is located at the outermost position at each position. That is, the first unit region 211A of these light emitting modules 201B is located closer to the rectangular outer edge of the light emitting surface as compared with the second unit region 211B.

Six light emitting modules 201C are arranged at positions in contact with the side SL, excluding the above-mentioned corners. Six light emitting modules 201C are also arranged at positions in contact with the side SR facing the side SL, excluding the above-mentioned corners. However, at the position in contact with the side SR, the light emitting module 201C is arranged in the backlight 301 in the form of inverting the light emitting module 201C in contact with the side SL. That is, in the light emitting module 201C in which the four first unit regions 211A are arranged along one side of the rectangular shape of the second main surface 210b, the first light emitting unit 101A is located at the outermost position in the backlight 301. It is supposed to be oriented.

Fourteen light emitting modules 201A are also arranged at positions in contact with the side SU and positions in contact with the side SD. At each position, the light emitting module 201A is arranged so that the first light emitting unit 101A is located on the outermost side. Light emitting modules 201D are arranged in 6 rows and 14 columns at positions other than the outermost light emitting module.

According to the backlight 301, the light distribution angle of the light emitting unit on the outermost peripheral side is narrower than that of the other light emitting units among the plurality of light emitting units arranged two-dimensionally. Therefore, it is possible to prevent light from leaking around the backlight 301. In particular, when the backlight is used in a liquid crystal display device having a narrow frame, it is considered that it is difficult to form a structure that shields the light spreading outward from the backlight due to the narrow circumference of the liquid crystal display panel. Even in such a case, by using the backlight 301, it is possible to suppress light leakage to the periphery of the backlight 301. On the other hand, since the light emitting unit arranged at a position other than the outermost circumference has a wide light distribution angle, uneven brightness is suppressed in most regions of the light emitting surface. Therefore, by using the light emitting modules 201A to 201D, it is possible to realize the backlight 301 having such excellent light emitting characteristics.

As described above, the position and number of light emitting units having a narrow light distribution angle in each light emitting module 201 can be arbitrarily set. Further, since the light emitting unit having a narrow light distribution angle can be formed by adjusting the position of the light source 20 arranged in the first recess 11 and the amount of the uncured material of the translucent member, a part of the light emitting module in the light emitting module. In order to narrow the light distribution angle of the light emitting unit, it is not necessary to prepare a plurality of types of light guide plates according to the position and number of the light emitting units, or a plurality of types of light sources having different light distribution angles. Further, the size as a surface light source and the aspect ratio of the screen can be arbitrarily changed depending on the number of combinations of light emitting modules. Therefore, the light emitting module 201 is excellent in versatility and can provide light emitting characteristics according to the application.

When the plurality of unit regions 211 include two or more first unit regions 211A, the amount of deviation of the position of the optical axis of the light source 20 with respect to the center of the first recess 11 is common among the two or more first unit regions 211A. It may or may not be different. It is not essential in the embodiment of the present disclosure that the amount of deviation of the position of the optical axis of the light source 20 with respect to the center of the first recess 11 is common among the plurality of first unit regions 211A.

In a configuration in which a plurality of light emitting modules are arranged two-dimensionally, the light guide plate 210 typically comes into direct contact with each other between two light emitting modules adjacent to each other in the row direction or the column direction. However, a light guide structure that optically connects the two light guide plates 210 adjacent to each other may be interposed. Such a light guide structure can be formed, for example, by applying a translucent adhesive to the side surface of the light guide plate 210 and then curing the applied adhesive. Alternatively, a plurality of light emitting modules 201A to 201D are arranged two-dimensionally at intervals from each other, the region between the two light guide plates 210 adjacent to each other is filled with a translucent resin material, and then the resin material is cured. The light guide structure may be formed by. As the material of the light guide structure located between the light guide plates 210, the same material as the above-mentioned joining member 23 can be used.

The light emitting modules 201A to 201D of the backlight 301 may be electrically connected to the wiring layer 60 of each light emitting module so as to be driven simultaneously, or by driving one or a plurality of light emitting modules individually. The wiring layer 60 of each light emitting module may be electrically connected so as to realize local dimming.

<Second embodiment>
FIG. 10A is a top view of an exemplary light emitting module according to a second embodiment of the present disclosure. The light emitting module 202 shown in FIG. 10A is different from the light emitting module 201 of the first embodiment in that it includes a third light emitting unit 101C instead of the second light emitting unit 101B. That is, the light emitting module 202 includes at least one first light emitting unit 101A and a plurality of third light emitting units 101C.

FIG. 10B shows an example of the appearance of the light guide plate of the light emitting module shown in FIG. 10A as viewed from the second main surface 210b side. As shown in FIG. 10B, in the light guide plate 210 of the present embodiment, the second unit region 211C is formed at a position corresponding to the third light emitting unit 101C.

FIG. 10C is an enlarged cross-sectional view showing the vicinity of the first recess 11 of the third light emitting unit 101C. Since the structure of the first light emitting unit 101A in the present embodiment is the same as the structure of the first light emitting unit 101A of the first embodiment, illustration and description thereof will be omitted.

As shown in FIG. 10C, in the third light emitting unit 101C, the upper surface 50Ca of the translucent member 50C has a second recess 51C recessed on the bottom surface 11b side of the first recess 11. The depth dc of the second recess 51C is smaller than the depth da of the first recess 51A of the first light emitting unit 101A. Here, the depth dc is a distance measured vertically from a straight line connecting the point 51C1 of the upper surface 50Ca, which is in contact with the inner side surface of the first recess 11, and the point 51C2, which is in contact with the side surface 20s of the light source 20. Depth da is defined in the same way.

Since the depth dc of the second recess 51C of the third light emitting unit 101C is smaller than the depth da of the first recess 51A of the first light emitting unit 101A, the light distribution angle of the third light emitting unit 101C is the first. It is wider than the light distribution angle of the light emitting unit 101A. Therefore, by using the light emitting module 202 to manufacture a plurality of types of light emitting modules as shown in FIGS. 8A to 8C, for example, a backlight having the same effect as that of the first embodiment can be realized. ..

(Other forms)
The light emitting module of the present disclosure is not limited to the above embodiment, and various modifications can be made. FIG. 11 is a schematic cross-sectional view showing an enlarged cross section in the vicinity of the first recess 11 of the second light emitting unit 101B, and shows another example of the shape of the translucent member 50B. In the example described with reference to FIG. 6C, the translucent member 50B is arranged only in the first recess 11. However, the shape of the translucent member 50 is not limited to this example. As shown in FIG. 11, a part of the translucent member 50 may be located on the first main surface 10a around the first recess 11 of the light guide plate 10.

12 and 13 show other examples of the shape of the translucent member 50. 12 and 13 show an enlarged cross section in the vicinity of the first recess 11 of the second light emitting unit 101B, similarly to FIG. 11. In the example shown in FIGS. 6C and 6D, the upper surface 50Ba of the translucent member 50B is substantially flat. However, as shown in FIGS. 12 and 13, the upper surface 50Ba of the translucent member 50B has a point 51B1 of the upper surface 50Ba in contact with the inner surface of the first recess 11, and a point 51B2 in contact with the side surface 20s of the light source 20. It may rise from a straight line connecting them (indicated by a broken line in FIGS. 12 and 13). In other words, the upper surface 50Ba may have a convex shape. Also in this case, as shown in FIG. 13, a part of the translucent member 50 may be located on the first main surface 10a around the first recess 11 of the light guide plate 10.

In each of the above-mentioned examples, the light emitting unit 101 has a lens structure on the second main surface 210b side of the light guide plate 210. The optical axis of the lens structure provided corresponding to the unit region 211 is typically aligned with the center of the unit region 211 on the second main surface 210b of the light guide plate 210. In such a configuration, focusing on each first unit region 211A, it can be said that the optical axis of the light source 20 is shifted from the center of the first unit region 211A on the first main surface 210a of the light guide plate 210.

The direction of this "shift" may be any direction perpendicular to the Z direction, and may be, for example, a direction parallel to any of two adjacent sides of the rectangular shape of the first unit region 211A. Alternatively, the direction of the "shift" may be parallel to the diagonal direction of the rectangular shape of the first unit region 211A. The direction of the shift of the optical axis of the light source 20 with respect to the center of the first unit region 211A may be non-parallel to two adjacent sides of the rectangular shape of the first unit region 211A.

On the contrary, the position of the optical axis of the lens structure may be shifted from the center of the unit region 211 on the second main surface 210b of the light guide plate 210. For example, of the plurality of unit regions 211, the optical axis of the lens structure arranged in each first unit region 211A may be shifted from the center of the first unit region 211A. In such a configuration, the optical axis of the light source 20 in the first unit region 211A may be aligned with the center of the first unit region 211A in the first main surface 210a of the light guide plate 210. However, here as well, the light source 20 in the first unit region 211A is arranged in the first recess 11 with its optical axis shifted in a certain direction from the center of the first recess 11.

It is also possible to obtain light distribution characteristics with lower symmetry by shifting the position of the optical axis of the lens structure from the center of the unit region 211 on the second main surface 210b of the light guide plate 210. The optical axis of the lens structure arranged in each second unit region 211B may be shifted from the center of the second unit region 211B. Similar to the shift direction of the optical axis of the light source 20 with respect to the center of the first unit region 211A, the shift direction of the optical axis of the lens structure with respect to the center of the unit region 211 is also a direction perpendicular to the Z direction. If there is, it may be in any direction.

In addition to shifting the position of the optical axis of the light source 20 from the center of the first unit region 211A on the first main surface 210a, the optical axis of the lens structure is shifted to the center of the first unit region 211A on the second main surface 210b. You may shift from. These shifts can be opposite (antiparallel) along a direction.

Further, in each of the above-mentioned examples, the center of the first recess 11 provided in the first main surface 210a of the light source plate 210 corresponding to each unit region 211 coincides with the center of the unit region 211 in the first main surface 210a. The position of the optical axis of the light source 20 is shifted from the center of the first recess 11 in the first recess 11. In such a configuration, the optical axis of the lens structure may be shifted from the center of the first unit region 211A on the second main surface 210b of the light guide plate 210.

Alternatively, in the first unit region 211A, the optical axis of the lens structure is aligned with the center of the first unit region 211A on the second main surface 210b of the light guide plate 210, and the center of the first recess 11 is aligned with the center of the first unit region 211A. It may be shifted from the center. For example, the shift amount and shift direction of the optical axis of the light source 20, the shift amount and shift direction of the optical axis of the lens structure, and the shift amount and shift of the center of the first recess 11 with reference to the center of the unit region 211. By individually controlling the direction of the light distribution, it is possible to make finer adjustments to the light distribution characteristics.

Further, for example, the first light emitting unit 101A having a narrow light distribution angle may be arranged at a position other than the outermost rows and columns of the light emitting module. The light emitting module may include at least one first light emitting unit 101A, and the light emitting module may include only a plurality of first light emitting units 101A. Further, when the light emitting module includes a plurality of first light emitting units 101A, the plurality of first light emitting units 101A may be adjacent to each other and continuously arranged in one light emitting module, or one light emitting unit may be continuously arranged. It may be arranged discretely and isolated in the module.

In a device having a display device, the state of the device, information for operating the device, and the like can be displayed at a specific position on the screen. The light emitting module of the present disclosure is also useful as a backlight of such a display device in which specific information is displayed in a specific area on the screen. When specific information is displayed in a specific area on the screen of the display device, the characteristics of the backlight in the specific area may be different from other areas in advance. For example, when the light emitting module is configured so that the first light emitting unit 101A is arranged in a specific area, the brightness seen from the front is enhanced by the narrow light distribution angle in the specific area. Therefore, it is possible to improve the visibility of the information displayed in the specific area when viewed from the front.

The embodiments of the present disclosure are useful for surface light sources and the like for various purposes. In particular, it can be advantageously applied to a backlight unit directed to a liquid crystal display device. The light emitting module or the surface light emitting light source according to the embodiment of the present disclosure can be suitably used for a backlight for a display device of a mobile device, a surface light emitting device capable of local dimming control, and the like, which are strictly required to reduce the thickness.

10 Light guide plate 10a 1st main surface 10b 2nd main surface 10c Curved surface part 11 1st concave portion 11b Bottom surface 12 2nd concave portion 12c 1st part 12d 2nd part 15A, 15B Intermediate through hole 20, 20B to 20P Light source 20b 2nd main Surface 20s Side surface 21 Light emitting element 21b Emission surface 21s Side surface 21t Electrode 22 Frequency conversion member 22a Main surface 23 Joining member 24 Light reflecting member 30 Light reflecting layer 30a First main surface 40 Light reflecting member 50, 50A, 50B, 50C, Transparent Optical members 50Aa, 50Ba, 50Ca Upper surface 51A First concave portion 51C Second concave portion 60 Wiring layer 100 Light emitting module 101 Light emitting unit 101A First light emitting unit 101B Second light emitting unit 101C Third light emitting unit 201, 201A to 201D, 202 Light emitting module 210 Light guide plate 210a First main surface 210b Second main surface 211 Unit area 211A First unit area 211B, 211C Second unit area 220 Light reflection layer 301 Backlight

Claims (15)

The first main surface and the second main surface located on the opposite side of the first main surface are arranged one-dimensionally or two-dimensionally, and at least one first unit region and a plurality of second unit regions are formed. A light guide plate including a plurality of unit regions including, and a plurality of first recesses located on the first main surface and corresponding to the plurality of unit regions.
A plurality of light sources provided on the first main surface of the light guide plate, each of which is a plurality of light sources arranged in the first recess corresponding to one of the plurality of unit regions.
A translucent member arranged in the first recess so as to cover at least a part of the side surface of the light source in each of the plurality of unit regions.
A light reflecting layer covering the surface of the light guide plate, which is located on the side opposite to the second main surface of the light guide plate, of the first main surface and the translucent member.
Equipped with
In the second unit region, the optical axis of the light source coincides with the center of the first recess on the first main surface.
In the at least one first unit region, the optical axis of the light source is deviated from the center of the first recess on the first main surface.
In a cross-sectional view perpendicular to the second main surface, the surface of the translucent member in the at least one first unit region is in contact with the inner surface of the first recess, and the side surface of the light source. It has a first recess that is recessed toward the second main surface of the light guide plate with reference to a virtual straight line connecting the points in contact with each other.
The surface of the translucent member in the plurality of second unit regions is guided with reference to a virtual straight line connecting a point in contact with the inner side surface of the first recess and a point in contact with the side surface of the light source. A light source module that is not recessed toward the second main surface of the light plate . The first main surface and the second main surface located on the opposite side of the first main surface are arranged one-dimensionally or two-dimensionally, and at least one first unit region and a plurality of second unit regions are formed. A light guide plate including a plurality of unit regions including, and a plurality of first recesses located on the first main surface and corresponding to the plurality of unit regions.
A plurality of light sources provided on the first main surface of the light guide plate, each of which is a plurality of light sources arranged in the first recess corresponding to one of the plurality of unit regions.
A translucent member arranged in the first recess so as to cover at least a part of the side surface of the light source in each of the plurality of unit regions.
A light reflecting layer covering the surface of the light guide plate, which is located on the side opposite to the second main surface of the light guide plate, of the first main surface and the translucent member.
Equipped with
In the second unit region, the optical axis of the light source coincides with the center of the first recess on the first main surface.
In the at least one first unit region, the optical axis of the light source is deviated from the center of the first recess on the first main surface.
In a cross-sectional view perpendicular to the second main surface, the surface of the translucent member in the at least one first unit region is in contact with the inner surface of the first recess, and the side surface of the light source. It has a first recess that is recessed toward the second main surface of the light guide plate with reference to a virtual straight line connecting the points in contact with each other.
The surface of the translucent member in the plurality of second unit regions is guided with reference to a virtual straight line connecting a point in contact with the inner side surface of the first recess and a point in contact with the side surface of the light source. It has a second recess that is recessed toward the second main surface of the light plate .
The light emitting module whose depth of the second recess is smaller than the depth of the first recess. The plurality of unit areas are arranged two-dimensionally in the row and column directions.
The light emitting module according to claim 1 or 2 , wherein a plurality of the first unit regions are arranged in the outermost row or column of the plurality of unit regions. 1. A plurality of lens structures provided on the second main surface of the light guide plate, each further comprising a plurality of lens structures arranged corresponding to one of the plurality of unit regions. The light emitting module according to any one of 3 to 3 . The optical axis of the lens structure coincides with the center of the first unit region on the second main surface.
The light emitting module according to claim 4 , wherein the optical axis of the light source is shifted from the center of the first unit region on the first main surface. The optical axis of the light source coincides with the center of the first unit region on the first main surface.
The light emitting module according to claim 4 , wherein the optical axis of the lens structure is shifted from the center of the first unit region on the second main surface. The optical axis of the light source is shifted from the center of the first unit region on the first main surface, and the optical axis of the lens structure is shifted from the center of the first unit region on the second main surface. The light source module according to claim 4 . The light emitting module according to claim 7 , wherein the shift direction of the optical axis of the light source is opposite to the shift direction of the optical axis of the lens structure. In the first unit region, the center of the first recess is shifted from the center of the first unit region.
The light emitting module according to any one of claims 4 to 8 , wherein the optical axis of the lens structure coincides with the center of the first unit region on the second main surface. In the first unit region, the center of the first recess coincides with the center of the first unit region.
The light emitting module according to any one of claims 4 to 8 , wherein the optical axis of the lens structure is shifted from the center of the first unit region on the second main surface. The light emitting module according to any one of claims 5 to 10 , wherein the first unit region has a rectangular shape, and the direction of the shift is parallel to any of two adjacent sides of the rectangular shape. The light emitting module according to any one of claims 5 to 10 , wherein the first unit region has a rectangular shape, and the direction of the shift is parallel to the diagonal direction of the rectangular shape. The light emitting module according to any one of claims 5 to 10 , wherein the first unit region has a rectangular shape, and the direction of the shift is non-parallel to two adjacent sides of the rectangular shape. The light guide plate has a plurality of second recesses provided on the second main surface.
Each of the plurality of second recesses is arranged corresponding to one of the plurality of unit areas.
The light emitting module according to any one of claims 4 to 13 , wherein the plurality of lens structures are provided in the plurality of second recesses, respectively. The light emitting module according to claim 14 , wherein each of the plurality of lens structures further includes a light reflecting member arranged in the second recess.

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