JP7375170B2 - Linear light emitting member and planar light emitting device - Google Patents

Description

The present invention relates to a linear light emitting member and a planar light emitting device.

Conventionally, a planar light-emitting device that emits light in a planar manner has been used as a backlight for a liquid crystal display, a lighting device, or the like. A planar light emitting device includes a linear light emitting member in which light emitting elements such as LEDs (Light Emitting Diodes) are arranged in a linear manner and a light guide plate, and the light guide plate diffuses light emitted from the linear light emitting member in a planar manner. By doing so, light is emitted in a planar manner. In recent years, liquid crystal displays are sometimes used outdoors for digital signage, etc., and in order to ensure the outdoor visibility of liquid crystal displays, it is necessary to improve the brightness of linear light emitting members and planar light emitting devices. It has been demanded.

In order to improve the brightness of a linear light emitting member, it is effective to increase the density of the arrangement of light emitting elements, but from the viewpoint of power and heat dissipation, it is difficult to increase the density indefinitely. Therefore, it is required to improve the luminous efficiency of linear light emitting members and planar light emitting devices.

Japanese Patent Application Publication No. 2005-159035

Patent Document 1 describes a light-emitting device that improves luminous efficiency by providing an inclined reflector around a light-emitting diode and efficiently extracting light from the light-emitting diode. In such light emitting devices, further improvement in luminous efficiency is required.

The linear light emitting member and the planar light emitting device according to the embodiments can improve luminous efficiency.

The linear light emitting member according to the embodiment includes a mounting board extending in a predetermined direction, a circuit board disposed on the mounting board and having an opening extending in a predetermined direction, an electrode disposed on the circuit board, and an opening. A plurality of light emitting elements are arranged on a mounting board along a predetermined direction inside the section and are electrically connected to electrodes, and a circuit board is arranged to surround the plurality of light emitting elements and emit light from the light emitting elements. The light emitting device has a reflective frame body, and the frame body is characterized in that the inner circumferential surface thereof protrudes so as to be curved in the direction of the light emitting element.

In the linear light-emitting member according to the embodiment, the frame extends from the center of the upper surface of the light-emitting element in the transverse direction of the linear light-emitting member, and the elevation angle of the tangent line touching the frame is 5 degrees or more and 30 degrees or less. Preferably, it is formed as follows.

In the linear light emitting member according to the embodiment, the light emitting element has a directional characteristic such that the intensity of the light emitted in the emitting direction having a predetermined elevation angle is maximum in the transverse direction of the linear light emitting member, Preferably, the frame is formed such that a curved surface extending from the upper end of the frame to the protrusion protruding in the direction of the light emitting element is positioned in the emission direction with respect to the center of the upper surface of the light emitting element.

In the linear light emitting member according to the embodiment, the electrode has an extension extending from the inner periphery of the frame, and the plurality of light emitting elements are electrically connected to the electrode via wires joined to the extension. preferably connected to.

In the linear light emitting member according to the embodiment, the circuit board has a plurality of openings along a predetermined direction, and the extension part extends between adjacent openings among the plurality of openings. , is preferable.

In the linear light emitting member according to the embodiment, it is preferable that the upper surface of the frame is formed in a planar shape parallel to the mounting board.

In the linear light emitting member according to the embodiment, the height of the circuit board is preferably lower than at least one light emitting element among the plurality of light emitting elements.

In the linear light emitting member according to the embodiment, it is preferable that the inner circumferential surface of the frame protrudes further inward than the outer edge of the opening.

A planar light-emitting device according to an embodiment includes a linear light-emitting member according to an embodiment, an entrance surface into which light from the linear light-emitting member is incident, and an exit surface through which light incident from the entrance surface is emitted. and a case that accommodates the linear light emitting member and the light guide plate, and the frame of the linear light emitting member is in contact with the incident surface.

A planar light-emitting device according to an embodiment includes a linear light-emitting member according to an embodiment, an entrance surface into which light from the linear light-emitting member is incident, and an exit surface through which light incident from the entrance surface is emitted. a light guide plate having a light guide plate, a reflecting member that covers the surface facing the incident surface and the surface facing the output surface and reflects light from the linear light emitting member, and housing the linear light emitting member, the light guide plate, and the reflecting member. The invention is characterized by having a case in which:

According to the embodiment, the planar light emitting device and the linear light emitting member make it possible to improve light emitting efficiency. The objects and advantages of the invention will be realized and obtained by means of the components and combinations particularly pointed out in the claims. Both the foregoing general description and the following detailed description are intended to be exemplary and explanatory and are not intended to limit the invention as claimed.

1 is a perspective view of a planar light emitting device 1. FIG. 1 is an exploded perspective view of a planar light emitting device 1. FIG. 1 is a cross-sectional view of a planar light emitting device 1. FIG. FIG. 2 is a front view of a linear light emitting member 2. FIG. FIG. 2 is a front view of a linear light emitting member 2. FIG. FIG. 2 is a cross-sectional view of a linear light emitting member 2. FIG. 7 is an enlarged sectional view of the linear light emitting member 2 of FIG. 6. FIG. It is a graph showing the relationship between the height of the sealing material 26 and the intensity ratio of light. It is a graph showing the relationship between the angle of a tangent and the intensity of light. FIG. 2 is a cross-sectional view of a linear light emitting member 2a. It is a sectional view of linear light emitting member 2b. It is a front view of the linear light emitting member 2c. It is a sectional view of the linear light emitting member 2c. It is a sectional view of linear light emitting member 2d. It is a front view of the linear light emitting member 2e. FIG. 2 is a cross-sectional view of a linear light emitting member 2e. It is a sectional view of linear light emitting member 2f. It is a front view of 2 g of linear light emitting members. FIG. 2 is a cross-sectional view of a linear light emitting member 2g. It is a front view of linear light emitting member 2h. It is a front view of the linear light emitting member 2i. FIG. 1 is a perspective view of a planar light emitting device 1j. FIG. 1 is an exploded perspective view of a planar light emitting device 1j. FIG. 1 is a cross-sectional view of a planar light emitting device 1j. It is a front view of the linear light emitting member 2j. FIG. 2 is a cross-sectional view of a linear light emitting member 2j.

Hereinafter, various embodiments of the present invention will be described with reference to the drawings. However, it should be noted that the technical scope of the present invention is not limited to these embodiments, but extends to the invention described in the claims and equivalents thereof.

FIG. 1 is a perspective view of a planar light emitting device 1 according to the first embodiment, FIG. 2 is an exploded perspective view of the planar light emitting device 1, and FIG. 3 is a sectional view of the planar light emitting device 1. It is. FIG. 3 is a sectional view taken along the line III--III in FIG. The planar light emitting device 1 is used, for example, as a backlight that is used as a light source to illuminate a transmissive display panel such as a liquid crystal panel from the back. The planar light emitting device 1 may be used as a light source for a lighting device and an information display device.

The planar light emitting device 1 includes a linear light emitting member 2, a light guide plate 11, a reflective sheet 12, a diffusion sheet 13, a light condensing sheet 14, a reflective polarizing plate 15, a spacer 16, and a case 17 that accommodates these inside. The case 17 can be separated into an upper case 17a and a lower case 17b. The case upper part 17a has an opening in the center, and the reflective polarizing plate 15 is exposed to the outside through the opening. Further, the lower case 17b has an opening near its end through which the power cable 18 is inserted. The power cable 18 supplies power to the linear light emitting member 2 from an external power source.

The light guide plate 11 has a flat, substantially rectangular parallelepiped shape. The light guide plate 11 includes an entrance surface 11a into which the light from the linear light emitting member 2 is incident, an exit surface 11b which is orthogonal to the entrance surface 11a and through which the light incident from the entrance surface 11a is exited, and an exit surface 11b. It has a reflecting surface 11c that faces each other and is provided with a fine uneven structure. Projections 11e are provided at both ends of the entrance surface 11a. The light guide plate 11 is formed using resin such as polycarbonate resin or acrylic resin. In addition, hereinafter, the direction in which the light emitting surface 11b of the light guide plate 11 is located may be referred to as the upper side of the planar light emitting device 1, and the direction in which the reflective surface 11c is located may be referred to as the bottom of the planar light emitting device 1.

The reflective sheet 12 is a thin film-like member provided below the light guide plate 11 . The reflective sheet 12 is a metal plate, film, white sheet, or the like that reflects light. The light-reflecting film is, for example, a film on which a vapor-deposited film of silver, aluminum, or the like is formed. The reflective sheet 12 has an opening near its end through which the power cable 18 is inserted.

The diffusion sheet 13 is a thin film-like member provided above the light guide plate 11. The diffusion sheet 13 is formed by, for example, dispersing silica particles in a translucent resin such as polycarbonate resin or acrylic resin. The light condensing sheet 14 is a thin film-like member provided above the diffusion sheet 13. The light condensing sheet 14 is, for example, a prism sheet. The reflective polarizing plate 15 is a thin film-like member provided above the light condensing sheet 14 . The reflective polarizing plate 15 has a multilayer structure made of resin.

The light incident on the entrance surface 11a of the light guide plate 11 travels toward the reflection surface 11c or the exit surface 11b. Light traveling from the incident surface 11a to the reflective surface 11c is reflected by the uneven structure of the reflective surface 11c or the reflective sheet 12, and travels toward the output surface 11b. Light traveling from the entrance surface 11a or the reflection surface 11c toward the exit surface 11b is emitted from the exit surface 11b.

The light emitted from the output surface 11b is sequentially incident on the diffusion sheet 13, the condensing sheet 14, and the reflective polarizing plate 15. The diffusion sheet 13 scatters the incident light and makes the distribution of the amount of light uniform. The condensing sheet 14 condenses the incident light in the direction of the reflective polarizing plate 15 . The reflective polarizing plate 15 transmits a specific polarized component of the incident light and reflects other polarized components. The reflected light is reflected by the reflective surface 11c of the light guide plate 11, the reflective sheet 12, etc., and enters the reflective polarizing plate 15 again while changing the polarization component. As a result, light having a specific polarization component and focused in a specific direction is uniformly emitted from the reflective polarizing plate 15.

A spacer 16 is provided between the opposing surface 11d of the light guide plate 11, which faces the incident surface 11a, and the side surface of the case 17. The spacer 16 has elasticity and presses the light guide plate 11 in the direction of the linear light emitting member 2 by its elastic force. The linear light emitting member 2 is a linear member on which a light emitting element is arranged, and is arranged inside the case 17 so that the light emitting element faces the incident surface 11a of the light guide plate 11. The linear light emitting member 2 is clamped and fixed between the adhesive 19 provided on the side surface of the case 17 and the protrusion 11e of the light guide plate 11 pressed by the spacer 16.

The distance between the surface of the protrusion 11e in contact with the linear light emitting member 2 and the incident surface 11a in the normal direction of the incident surface 11a is formed to be approximately the same as the thickness of the linear light emitting member 2. Thereby, as shown in FIG. 3, the linear light emitting member 2 and the entrance surface 11a come into contact.

4 and 5 are front views of the linear light emitting member 2 according to the first embodiment, and FIGS. 6 and 7 are sectional views of the linear light emitting member 2. FIG. 5 is a drawing in which the frame body 25 is not shown in FIG. 4. FIG. 6 is a sectional view taken along the line VI-VI in FIG. 4. FIG. 7 is an enlarged view of FIG. 6.

The linear light emitting member 2 roughly includes a mounting board 21 , a circuit board 22 , an electrode 23 , a plurality of light emitting elements 24 , a frame 25 , and a sealing material 26 .

The mounting board 21 is a linear member extending in the X-axis direction (see FIG. 4). The mounting board 21 has an upper surface and a lower surface that are parallel to the X-axis direction and the Y-axis direction (see FIG. 4) orthogonal to the X-axis direction. The mounting board 21 is made of, for example, aluminum or alumina. The mounting board 21 is formed to have a thickness of, for example, 0.7 mm. Further, the width L1 (see FIG. 6) of the mounting board 21 in the Y-axis direction, which is the lateral direction, is set to 10 mm or less, and is set to 5 mm, for example. Note that the X-axis direction is an example of a predetermined direction.

The circuit board 22 is arranged on the upper surface of the mounting board 21. The circuit board 22 has a flat plate shape extending in the X-axis direction and parallel to the X-axis direction and the Y-axis direction. The circuit board 22 is bonded to the mounting board 21 using an adhesive such as an adhesive sheet. The circuit board 22 is formed using electrically insulating resin such as phenol resin, epoxy resin, polyimide resin, or polyester resin. The circuit board 22 is formed to have a thickness of, for example, 0.1 mm. The circuit board 22 has one or more openings 221 extending in the X-axis direction in the center thereof, and the upper surface of the mounting board 21 is exposed from the opening 221. One or more openings 221 are provided along the X-axis direction.

The electrodes 23 are a pair of metal members extending in the X-axis direction, and both are arranged on the circuit board 22. The electrode 23 is formed by patterning a conductor such as gold or copper on the circuit board 22. The electrode 23 is formed to have a thickness of 35 μm, for example. The electrode 23 may be adhered to the circuit board 22 with an adhesive member such as an adhesive or an adhesive sheet. The adhesive member is formed to have a thickness of 25 μm, for example. Further, the upper surface of the electrode 23 may be plated with nickel. The nickel plating is formed to have a thickness of, for example, 10 μm. The electrode 23 is electrically connected to the power cable 18 via a connector 231 provided at an end, and one of the electrodes functions as an anode and the other functions as a cathode. A solder resist 222 (not shown in FIG. 4) is applied to the upper surfaces of the circuit board 22 and the electrodes 23 except for the portion where the connector 231 is provided.

A portion of the electrode 23 is provided at the bottom of the frame 25. The electrode 23 has an extending portion 232 extending from the inner periphery of the frame 25 . The extending portion 232 extends from the inner periphery of the frame body 25 between adjacent openings 221 among the plurality of openings 221 .

The light emitting element 24 is an element that emits light with a predetermined wavelength, and is, for example, a blue LED made of an InGan compound semiconductor that emits light with a wavelength of 440 to 455 nm. For example, the light emitting element 24 has a width of 0.65 mm in the X-axis direction and a width in the Y-axis direction, and a height of 0.2 mm. The plurality of light emitting elements 24 are arranged along the X-axis direction on the upper surface of the mounting board 21 exposed from the opening 221 inside the opening 221 of the circuit board 22, and are attached to the mounting board 21 by die bonding with silver paste, solder, etc. Fixed. The distance between the plurality of light emitting elements 24 in the X-axis direction is, for example, 1.4 mm.

The light emitting element 24 is electrically connected to the electrode 23. In the example shown in FIG. 4, a plurality of light emitting elements 24 arranged along the X-axis direction are connected in series every eight through wires 241 connected to their upper surfaces. Of the eight light emitting elements, each of the light emitting elements 24 at both ends is electrically connected to the electrode 23 via a wire 241 joined to the extending portion 232 of the electrode 23.

The height of the top surface of the light emitting element 24 substantially matches the height of the top surface of the electrode 23. For example, when the thickness of the circuit board 22 is 0.1 mm, the thickness of the adhesive member is 25 μm, the thickness of the electrode 23 is 35 μm, and the thickness of the nickel plating is 10 μm, the upper surface of the electrode 23 is It is located at a height of 0.17 mm from the top surface. In this case, the height of the light emitting element 24 is formed to be 0.2 mm, so that the height of the upper surface of the light emitting element 24 substantially matches the height of the upper surface of the electrode 23. This facilitates and stabilizes the bonding of the wire 241 that electrically connects the electrode 23 and the light emitting element 24. Note that the height of the top surface of the light emitting element 24 substantially matches the height of the top surface of the electrode 23 when the difference between the height of the top surface of the light emitting device 24 and the height of the top surface of the electrode 23 is 0.05 mm or less. means.

The frame 25 is an annular member provided on the circuit board 22 so as to surround the plurality of light emitting elements 24 . The frame 25 is provided so that its inner periphery substantially coincides with the outer periphery of the opening 221 of the circuit board 22 . The frame 25 is made of a white resin that reflects light from the light emitting element 24, such as silicone resin or epoxy resin in which fine particles such as titanium oxide are dispersed. The frame 25 is formed, for example, to have a thickness of 1 mm and a height of 0.3 mm.

The inner circumferential surface of the frame body 25 protrudes in a curved manner toward the light emitting element 24 . That is, as shown in FIG. 7, the inner peripheral surface of the frame 25 is such that the distance L2 between the protrusion 251 protruding in the direction of the light emitting element 24 and the light emitting element 24 is equal to the lower end of the inner peripheral surface of the frame 25. The distance L3 between the portion 252 and the light emitting element 24 is smaller than the distance L3. For example, when the distance L3 is 0.9 mm, the distance L2 is formed to be approximately 0.8 mm.

The frame 25 is formed such that the elevation angle D1 (see FIG. 7) of a tangent to the frame 25 extending in the Y-axis direction from the center portion 242 of the upper surface of the light emitting element is 5 degrees or more and 30 degrees or less.

The frame body 25 is formed by applying a resin to the circuit board 22 and curing the resin while the inner peripheral surface is curved due to the surface tension of the resin. The frame body 25 may be arranged by bonding a resin whose inner circumferential surface is curved in advance to the circuit board 22 using a mold or the like. The frame 25 may have a curved outer peripheral surface or may have a planar shape. When the outer peripheral surface of the frame 25 has a planar shape perpendicular to the mounting board 21, the position of the outer peripheral surface of the frame 25 may coincide with the position of the outer peripheral surface of the mounting board 21 or the circuit board 22. Thereby, the width of the linear light emitting member 2 in the Y-axis direction can be minimized.

The sealing material 26 is a member that seals the plurality of light emitting elements 24. The sealing material 26 is filled into the space formed by the mounting board 21 and the frame 25 to a height such that the wire 241 connected to the upper surface of the light emitting element 24 is not exposed. The sealing material 26 is made of a material in which fluorescent material is dispersed in a resin that is transparent to the light emitted by the light emitting element 24 . When the light emitting element 24 is a blue LED, the sealing material 26 is formed of, for example, a material in which YAG (Yttrium Aluminum Garnet) is dispersed in a resin such as epoxy resin or silicone resin. Thereby, the blue light emitted by the light emitting element 24 and the yellow light emitted by YAG absorbing the blue light are emitted from the sealing material 26, and by mixing these, white light is obtained.

FIG. 8 is a graph showing the relationship between the height of the sealing material 26 and the light intensity ratio. The horizontal axis of FIG. 8 is the height H of the top surface of the sealing material 26 with respect to the top surface of the light emitting element 24, and the vertical axis is the light emission of the linear light emitting member 2, where the height H is 0.5 mm as 100%. It is a ratio of strength. Note that FIG. 8 is a graph when the distance L2 between the protrusion 251 and the light emitting element 24 is 0.325 mm.

According to FIG. 8, the height H of the upper surface of the sealing material 26 is preferably 0.1 mm or more and 0.2 mm or less. As a result, the ratio of the light emission intensity of the linear light emitting member 2 to that when the height H is 0.5 mm becomes 106% or more. Moreover, it is more preferable that the height H of the upper surface of the sealing material 26 is 0.15 mm. Thereby, the light emission intensity of the linear light emitting member 2 becomes maximum.

The encapsulant 26 also has a ratio of the height H from the upper surface of the light emitting element 24 to the upper surface of the encapsulant 26 to the distance L2 from the side surface of the light emitting element 24 to the inner peripheral surface of the frame 25 in the Y-axis direction. may be filled to a height of 0.4 or more and 0.5 or less. More preferably, the sealing material 26 may be filled to a height such that the ratio of the height H to the distance L3 is 0.45 or more and 0.47 or less. For example, when the distance L2 is 0.8 mm, the sealing material 26 is filled to a height such that the height H is 0.37 mm. Thereby, the light emission intensity of the linear light emitting member 2 increases regardless of the size of the distance L2.

As described above, in the linear light-emitting member 2, the inner peripheral surface of the frame 25 is curved in the direction of the light-emitting element 24 by having the protrusion 251 that projects in the direction of the light-emitting element 24. Thereby, the linear light emitting member 2 can improve luminous efficiency.

That is, since the inner circumferential surface of the frame 25 is curved in the direction of the light emitting element 24, the light reflected by the curved surface from the protrusion 251 to the upper end 253 of the frame 25 is reflected by the incident surface 11a of the light guide plate 11. is reflected toward the normal direction of . As a result, the proportion of light reflected by the incident surface 11a is reduced, and the efficiency of light extraction from the linear light emitting member 2 to the light guide plate 11 is improved.

Further, the light reflected by the curved surface extending from the protrusion 251 to the lower end 252 of the frame 25 is reflected toward the mounting board 21 . As a result, the light is reflected by the mounting board 21 and travels in the direction of the incident surface 11a, so that the light extraction efficiency from the linear light emitting member 2 to the light guide plate 11 is improved. If the inner circumferential surface of the frame body 25 is not curved, the light emitted from the light emitting element 24 in a direction with a low elevation angle is repeatedly reflected between the inner circumferential surfaces of the opposing frame bodies 25 and reaches the incident surface 11a. , it is attenuated by multiple reflections. Since the inner circumferential surface of the frame body 25 is curved, the light emitted in the direction of a low elevation angle is reflected once by the curved surface from the protrusion part 251 to the lower end part 252 of the frame body 25 and the mounting board 21. It becomes possible for the light to reach the incident surface 11a. Therefore, attenuation of light emitted from the light emitting element 24 in a direction with a low elevation angle due to reflection is suppressed, and light extraction efficiency is improved.

Further, since the thickness of the lower end portion 252 of the frame body 25 is thinner than the thickness of the protrusion portion 251, the area on the circuit board 22 for arranging the frame body 25 becomes smaller. Thereby, the width of the linear light emitting member 2 can be reduced, and the planar light emitting device 1 can be made thinner.

Further, in the linear light emitting member 2, the electrode 23 has an extension part 232 extending from the lower part of the frame 25, and the plurality of light emitting elements 24 are connected to each other via wires 241 joined to the extension part 232. It is electrically connected to the electrode 23. This reduces the possibility that the linear light emitting member 2 will be damaged by external force.

That is, when the light emitting element 24 is joined to the electrode 23 at the lower part of the frame 25 by the wire 241, the wire 241 passes through the lower part of the frame 25. In this case, when the frame 25 receives an external force in the direction of the circuit board 22 due to contact with the light guide plate 11, the wire 241 at the bottom of the frame 25 may break and the linear light emitting member 2 may be damaged. There was sex. On the other hand, since the wire 241 is joined to the extension part 232 in the linear light emitting member 2, the wire 241 is no longer located at the lower part of the frame 25, so the linear light emitting member 2 is damaged by external force. The possibility is reduced.

Since the wires no longer pass through the lower part of the frame 25, the outer circumferential surface of the frame 25 is curved, making it possible to have a larger shape in the Y-axis direction than the mounting board 21 and the circuit board 22. It becomes easier to hold the shaped light emitting member 2. Further, it becomes possible to form the frame body 25 in advance using a mold or the like and then arrange it on the circuit board 22, which improves manufacturing efficiency.

Furthermore, in the linear light emitting member 2 , the circuit board 22 has a plurality of openings 221 , and the extending portion 232 extends between the plurality of openings 221 . Thereby, the opening portion 221 and the extension portion 232 can be arranged so as to be aligned in the X-axis direction, and the width of the linear light-emitting member 2 in the Y-axis direction can be reduced. Note that the circuit board 22 may have only one opening 221.

Further, in the planar light emitting device 1, the frame 25 is in contact with the entrance surface 11a of the light guide plate 11. This prevents light from the light emitting element 24 from leaking through the gap between the frame 25 and the entrance surface 11a, and improves the efficiency of light extraction from the linear light emitting member 2 to the light guide plate 11.

In the linear light-emitting member 2, the frame 25 extends in the Y-axis direction from the center portion 242 of the upper surface of the light-emitting element 24 so that the elevation angle of a tangent that touches the frame 25 is 5 degrees or more and 30 degrees or less. It is formed. Thereby, the linear light emitting member 2 can further improve the luminous efficiency.

Below, the relationship between the elevation angle of the tangent to the frame 25 extending in the Y-axis direction from the center portion 242 of the upper surface of the light emitting element 24 and the luminous efficiency will be described. FIG. 9 is a graph showing the relationship between the angle of the tangent to the frame 25 extending in the Y-axis direction from the center portion 242 of the upper surface of the light emitting element 24 and the light intensity ratio. FIG. 9 is a graph plotting changes in the intensity of light emitted from the linear light emitting member 2 when the angle of the tangent is changed by changing the height of the frame 25. In FIG. 9, the angle of the tangent line is shown as an angle with respect to vertically upward. In addition, the intensity of light is shown as a relative value when its maximum value is taken as 100%.

As shown in FIG. 9, when the tangent angle is 60 degrees or more, the intensity of light is 93% or more, and it can be seen that a large amount of light is extracted from the linear light emitting member 2. On the other hand, when the angle of the tangent is 85 degrees or more, the height of the upper end 253 of the frame 25 is close to the height of the upper surface of the light emitting element 24, and the sealing material 26 is connected to the upper surface of the light emitting element 24. It becomes difficult to fill the wires 241 to a height where the exposed wires 241 are not exposed. Therefore, it is preferable that the tangent line has an angle of 60 degrees or more and 85 degrees or less with respect to the vertically upward direction. That is, when converted into an elevation angle that is an angle with respect to the horizontal direction, the elevation angle of the tangent line is preferably 5 degrees or more and 30 degrees or less.

Note that the upper surface of the sealing material 26 may be formed into a concave shape in which the outer peripheral portion is higher than the central portion. Thereby, the traveling direction of the light emitted from the sealing material 26 becomes close to vertically upward, and the luminous efficiency is improved.

FIG. 10 is a cross-sectional view of a linear light emitting member 2a according to the second embodiment. FIG. 10 is a cross-sectional view similar to FIG. 6. The linear light emitting member 2a is different from the linear light emitting member 2 in the shape of the frame.

Like the frame 25, the inner peripheral surface of the frame 25a of the linear light emitting member 2a is curved so as to be convex in the direction of the light emitting element 24. For example, the frame body 25a is formed to have a thickness of 1 mm and a height of 0.9 mm.

The light emitting element 24 has a directional characteristic such that the intensity of the emitted light is maximum in the emitting direction having the elevation angle D2 in the Y-axis direction. The elevation angle D2 is, for example, 40 degrees. The frame 25a has a curved surface extending from the upper end 253 of the frame 25a to the protrusion 251 that protrudes in the direction of the light emitting element 24, and is positioned in a direction having an elevation angle D2 when viewed from the center 242 of the upper surface of the light emitting element 24. It is formed like this. Thereby, the linear light emitting member 2a can further improve the luminous efficiency.

That is, the light emitted from the light emitting element 24 and reflected by the curved surface extending from the upper end 253 of the frame 25 to the protrusion 251 travels in the direction of the incident surface 11a of the light guide plate 11, and is reflected once. The light is incident on the surface 11a. By locating such a curved surface in the emission direction having the elevation angle D2, the linear light emitting member 2a can make the light with the maximum intensity enter the incident surface 11a with one reflection, and efficiently emit light. This allows the light to enter the light guide plate 11.

FIG. 11 is a sectional view of a linear light emitting member 2b according to the third embodiment. FIG. 11 is a cross-sectional view similar to FIG. 6 . The linear light emitting member 2b is different from the linear light emitting member 2 in the shape of the frame.

Like the frame 25, the inner peripheral surface of the frame 25b of the linear light emitting member 2b is curved so as to be convex in the direction of the light emitting element 24. The upper surface 254b of the frame 25b is formed into a planar shape parallel to the mounting board 21. As a result, when the frame body 25b comes into contact with the incident surface 11a of the light guide plate 11, the incident surface 11a and the mounting board 21 tend to become parallel, and the light extraction efficiency from the linear light emitting member 2 to the light guide plate 11 is improved. Improved.

Note that the intersection between the inner circumferential surface of the frame 25b and the top surface 254b of the frame 25b may be a contact point of a tangent that extends from the center portion 242 of the top surface of the light emitting element 24 in the Y-axis direction and touches the frame 25b. preferable. Further, the frame body 25b is located such that, for example, the contact point is located at a position where the intensity ratio of the light emitted from the linear light emitting member 2b is 93% (that is, a position where the elevation angle of the tangent line is 30 degrees or less). It is preferable to have a shape such that Thereby, even if the upper surface 254b is provided, the reflection efficiency of the inner circumferential surface of the frame body 25b does not decrease, so that the luminous efficiency of the linear light emitting member 2b does not decrease. Moreover, by providing the intersection, it is possible to prevent the sealing material 26 from creeping up onto the upper surface 254b when filling the sealing material 26. Furthermore, since it becomes easier to adjust the amount of the sealing material 26 based on the intersection, it becomes easier to form the sealing material 26 into a shape with a convex bottom surface or a convex top surface.

FIG. 12 is a front view of a linear light emitting member 2c according to the fourth embodiment, and FIG. 13 is a sectional view of the linear light emitting member 2c. FIG. 13 is a sectional view taken along the line XIII-XIII in FIG. 12.

The frame body 25c of the linear light emitting member 2c is provided on the mounting board 21 exposed from the opening 221c of the circuit board 22 so as to surround the plurality of light emitting elements 24. That is, the linear light emitting member 2c has a plurality of frames 25c by having the frame 25c inside each of the plurality of openings 221c. Each of the frames 25c has a pair of extending portions 255c facing each other and extending in the X-axis direction, and an end portion 256c joined to each of the pair of extending portions 255c.

Eight light emitting elements 24 are connected in series via wires 241c connected to the upper surface thereof. Of the eight light emitting elements, each of the light emitting elements 24 at both ends is electrically connected to the electrode 23c via a wire 241c joined to the extending portion 232c of the electrode 23c. The wire 241c joined to the light emitting element 24 and the extension part 232c at both ends passes inside or below the end part 256c of the frame body 25c.

The end portion 256c of the frame body 25c is formed by applying resin to the mounting board 21. The extending portion 255c may be formed by applying resin to the mounting board 21, or may be formed by placing a resin molded in advance using a mold or the like. That is, since the wire 241c is not provided at the lower part of the extending portion 255c, it is possible to use pre-molded resin as the extending portion 255c.

Further, the extending portion 255c may be formed higher than the end portion 256c. As a result, only the extending portion 255c through which the wire does not pass comes into contact with the incident surface 11a of the light guide plate 11, reducing the possibility that the wire will break. Note that the end portion 256c may be formed higher than the extending portion 255c, and the wire 241c may pass inside or below the extending portion 255c.

In the above description, the circuit board 22 of the linear light emitting member 2c has a plurality of openings 221c, but it may have one opening 221c.

FIG. 14 is a sectional view of a linear light emitting member 2d according to the fifth embodiment. FIG. 14 is a cross-sectional view similar to FIG. 13. The linear light emitting member 2d is different from the linear light emitting member 2c in the shape of the frame.

The frame 25d of the linear light emitting member 2d has a horizontal surface 257d formed from the inner peripheral surface toward the inside of the frame 25d above the protrusion 251, and extends upward from the end of the horizontal surface 257d. It has a vertical surface 258d. Thereby, the frame body 25d has a cross-sectional shape in which a right-angled notch is provided in the upper part. The horizontal surface 257d is formed so that its height is approximately the same as the height of the upper surface of the sealing material 26. This makes it possible to fill the sealing material 26 based on the height of the horizontal surface 257d, making it easy to fill an appropriate amount of the sealing material 26, improving manufacturing efficiency.

FIG. 15 is a front view of a linear light emitting member 2e according to the sixth embodiment, and FIG. 16 is a sectional view of the linear light emitting member 2e. FIG. 16 is a sectional view taken along the line XVI-XVI in FIG. 15. The linear light emitting member 2e is different from the linear light emitting member 2c in the shape of the frame.

The frame body 25e of the linear light emitting member 2e has a pair of extending portions 255e that face each other and extend in the X-axis direction, and end portions 256e that are joined to each of the pair of extending portions 255e. The circuit board 22e included in the linear light emitting member 2e has a shape such that both ends of the mounting board 21 in the Y-axis direction are exposed except for the area around the connector 231. The extending portions 255e of the frame body 25e are provided at both ends in the Y-axis direction of the mounting board 21 exposed by the circuit board 22e. That is, the frame body 25e is provided so that the circuit board 22e, the electrode 23, and the light emitting element 24 are located between the pair of extension parts 255e.

The sealing material 26e included in the linear light emitting member 2e seals the circuit board 22e, the electrode 23, and the light emitting element 24. Thereby, the linear light-emitting member 2e can increase the ratio of the width of the sealing material 26e in the Y-axis direction to the width of the linear light-emitting member 2e in the Y-axis direction, and it is possible to increase the area of the light-emitting surface. possible.

FIG. 17 is a cross-sectional view of a linear light emitting member 2f according to the seventh embodiment. FIG. 17 is a cross-sectional view similar to FIG. 6. Note that the vertical scale of FIG. 17 has been changed from that of FIG. 6. The linear light emitting member 2f includes a mounting board 21, a circuit board 27f, a plurality of light emitting elements 24, a frame 25f, and a sealing material 26.

The circuit board 27f is a flexible printed circuit board (FPC) arranged on the upper surface of the mounting board 21. The circuit board 27f has a base material 22f, an electrode 23f, and an insulating layer 222f.

The circuit board 27f is provided so that the height of the top surface is lower than the height of the top surface of the light emitting element 24. For example, the height of the circuit board 27f is 1/3 to 1/2 of the height of the light emitting element 24. If the height of the light emitting element 24 is 0.2 mm, the height of the circuit board 27f is, for example, 85 μm. When the heights of the plurality of light emitting elements 24 are different from each other, the circuit board 27f is provided so that the height is lower than the height of at least one light emitting element among the plurality of light emitting elements 24.

The base material 22f is a flat member that is bonded to the mounting board 21 using an adhesive member such as an adhesive sheet. The base material 22f is formed of a light transmitting material that transmits the light emitted from the light emitting element 24. The light transmitting material is, for example, a synthetic resin such as polyimide. An opening 221 extending in the X-axis direction is formed in the center of the base material 22f, and the upper surface of the mounting board 21 is exposed from the opening 221. The opening 221 is provided along the X-axis direction.

The base material 22f is formed of, for example, a colorless and transparent light transmitting material. As a result, the blue light in the wavelength band of 440 to 495 nm emitted from the light emitting element 24 can easily pass through the base material 22f, so that the blue light can be easily reflected by the highly reflective layer on the surface of the mounting board 21, so that it forms a linear shape. The light emitting efficiency of the light emitting member 2f is improved. The base material 22f may be formed of a colored transparent material such as white, yellow, or brown.

The thickness of the base material 22f is, for example, 5 μm, 7 μm, 12.5 μm, 25 μm, 50 μm, or 75 μm. The thickness of the base material 22f may be greater than 75 μm. When the thickness of the base material 22f is 25 μm or more, the dielectric strength voltage exceeds 10 kV, and therefore short circuit between the mounting board 21 and the electrode 23f is prevented.

Further, the base material 22f may be formed by stacking a plurality of light transmitting materials. Thereby, the thickness of the base material 22f can be easily adjusted. For example, even if two layers of light-transmitting material with a thickness of 12.5 μm are used as the base material 22f, the dielectric withstand voltage exceeds 10 kV, resulting in a short circuit between the mounting board 21 and the electrode 23f. is prevented.

The electrodes 23f are a pair of metal members extending in the X-axis direction, and both are arranged on the base material 22f. The electrode 23f is formed by patterning a conductor such as gold, silver, or copper on the circuit board 22. When the electrode 23f is made of silver, blue light with a wavelength of 440 nm to 495 nm emitted from the light emitting element 24 is more likely to be reflected by the electrode 23f compared to gold or copper, so that the luminous efficiency of the linear light emitting member 2f is reduced. will improve.

The electrode 23f is bonded to the base material 22f with an adhesive member such as an adhesive or an adhesive sheet. The electrode 23f is electrically connected to the power cable 18 via a connector 231 provided at an end, and one of the electrodes functions as an anode and the other functions as a cathode.

The insulating layer 222f is formed on the upper surface of the base material 22f and the electrode 23f, excluding the portion where the connector 231 is provided. The insulating layer 222f is formed of a synthetic resin having a dielectric strength voltage lower than that of the base material 22f. For example, the insulating layer 222f is formed of a film coverlay such as polyimide resin, or a solder resist such as epoxy or silicone resin.

As explained above, in the linear light emitting member 2f, the height of the upper surface of the circuit board 27f is formed to be lower than the height of the upper surface of the plurality of light emitting elements 24. This improves the luminous efficiency of the linear light emitting member 2f. That is, by forming the height of the top surface of the circuit board 27f to be lower than the height of the top surface of the light emitting element 24, the proportion of light directed toward the side surface of the circuit board 27f among the light emitted from the side surface of the light emitting element 24 is reduced. becomes smaller, and the proportion of light directed toward the frame body 28 becomes larger. Since the reflectance of the frame 28 is greater than the reflectance of the circuit board 27f, more light is reflected by the frame 28 and emitted to the outside of the linear light emitting member 2f. This improves the luminous efficiency of the linear light emitting member 2f. Further, since the circuit board 27f is a flexible printed circuit board, it is easy to form the height of the top surface of the circuit board 27f lower than the height of the top surface of the light emitting element 24.

In addition, in the linear light emitting member 2f, the opening of the base material 22f may be provided only in the vicinity of the light emitting element 24. As a result, the electrode 23f can be placed near the light emitting element 24, so the length of the wire connecting the electrode 23f and the light emitting element 24 is shortened, reducing the possibility that the wire will break.

FIG. 18 is a plan view of a linear light emitting member 2g according to the eighth embodiment, and FIG. 19 is a sectional view of the linear light emitting member 2g. FIG. 19 is a sectional view taken along the line XIX-XIX in FIG. 18. The linear light emitting member 2g differs from the linear light emitting member 2f in that it has a circuit board 27g instead of the circuit board 27f.

The circuit board 27g is a flexible printed circuit board placed on the upper surface of the mounting board 21. The circuit board 27g includes a base material 22g, an electrode 23f, and an insulating layer 222f.

The base material 22g is a flat member that is bonded to the mounting board 21 using an adhesive. The base material 22f is formed of a light transmitting material that transmits the light emitted from the light emitting element 24. The base material 22f may be formed by stacking a plurality of light transmitting materials. The base material 22g differs from the base material 22f in that no opening is formed in the center thereof. Thereby, the plurality of light emitting elements 24 are not directly mounted on the upper surface of the mounting board 21, but are mounted on the upper surface of the base material 22g. That is, the plurality of light emitting elements 24 are mounted on the mounting board 21 via the circuit board 27g.

In this way, in the linear light emitting member 2g, the light emitting element 24 is mounted on the mounting board 21 via the circuit board 27g. This increases the proportion of light directed toward the frame body 28 among the light emitted from the side surface of the light emitting element 24, so that the linear light emitting member 2g can further improve luminous efficiency. Moreover, the linear light-emitting member 2g makes it possible to improve the dielectric strength voltage between the light-emitting element 24 and the mounting board 21 compared to the case where the light-emitting element 24 is directly mounted on the upper surface of the mounting board 21.

Further, in the linear light emitting member 2g, the circuit board 27g is a flexible printed circuit board. Thereby, the linear light emitting member 2g can further improve the dielectric strength voltage. For example, the withstand voltage of FPC is about 10 kV, and the withstand voltage of FR-4 used as a rigid circuit board is 1.32 kV. Therefore, since the circuit board 27g is a flexible printed circuit board, the withstand voltage is approximately 10 times higher than when the circuit board 27g is a rigid circuit board.

FIG. 20 is a plan view of a linear light emitting member 2h according to the ninth embodiment. The linear light emitting member 2h differs from the linear light emitting member 2f in that it has a circuit board 27h instead of the circuit board 27f.

The circuit board 27h is a flexible printed circuit board placed on the top surface of the mounting board. The circuit board 27g has a base material 22h, an electrode 23h, and an insulating layer 222h.

The base material 22h is a flat member that is bonded to the mounting board 21 using an adhesive. The base material 22h is formed of a light transmitting material that transmits light emitted from the light emitting element 24. The base material 22f may be formed by stacking a plurality of light transmitting materials. One or more openings 221 extending in the X-axis direction are formed in the center of the base material 22f, and the upper surface of the mounting board 21 is exposed from the openings 221.

The base material 22h is formed so that its width in the X-axis direction is larger than the width of the mounting board 21 in the X-axis direction. As a result, at least one end of the base material 22h in the X-axis direction further extends from the end of the upper surface of the mounting board 21 in the X-axis direction. In FIG. 20, one end E1 of the base material 22h extends further in the X-axis direction (downward in FIG. 20) from one end E2 (indicated by a dotted line in FIG. 20) of the mounting board 21 in the X-axis direction. It's out.

The electrodes 23h are a pair of metal members extending in the X-axis direction, and both are arranged on the base material 22h. The electrode 23h is formed by patterning a conductor on the upper surface of the base material 22h. The electrode 23f is bonded to the base material 22h using an adhesive member. One of the electrodes 23h functions as an anode and the other functions as a cathode. At least one end of the electrode 23h in the X-axis direction further extends from the end of the upper surface of the mounting board 21 in the X-axis direction. As a result, the circuit board 27h is arranged such that at least one end in the longitudinal direction extends from the end of the mounting board 21 and is spaced apart from the mounting board 21.

The end of the circuit board 27h extending from the mounting board 21 is led out to the outside of the planar light emitting device 1 through an opening provided in the case 17 (see FIG. 2) of the planar light emitting device 1. Since the circuit board 27h is a flexible printed circuit board, the linear light emitting member 2h can be directly connected to an external power source by using the lead-out portion as a wiring. In this way, at least one end of the circuit board 27h, which is a flexible printed circuit board, extends from the mounting board 21, so that the linear light emitting member 2h can be connected to the connector and cable for connecting the electrode 23h to an external power source. This makes it possible to reduce the manufacturing cost of the planar light emitting device 1.

The insulating layer 222h is formed on the upper surfaces of the base material 22h and the electrodes 23h, excluding the portion extending from the mounting board 21. In FIG. 20, the insulating layer 222h is formed only in the region above the dotted line indicating the end E2 of the base material 22h and the electrode 23h. The insulating layer 222h is formed of a synthetic resin having an insulator voltage lower than the insulator voltage of the base material 22f. In this manner, the insulating layer 222h is provided only on the portion of the circuit board 27h that extends from the mounting board 21, thereby making the extended portion thinner. Thereby, the linear light emitting member 2h enables easy handling of the portion of the circuit board 27h extending from the mounting board 21. In particular, when the extended portion is inserted into a connector of an external power source, the thinner extended portion facilitates insertion into the connector.

In the above description, the insulating layer 222h is formed on the upper surfaces of the base material 22h and the electrodes 23h excluding the portion extending from the mounting board 21, but the present invention is not limited to such an example. The insulating layer 222h may be formed in any region on the upper surface of the base material 22h and the electrode 23h as long as a part of the electrode 23h is exposed and the electrode 23h can be connected to an external power source.

FIG. 21 is a plan view of a linear light emitting member 2i according to the tenth embodiment. The linear light emitting member 2i differs from the linear light emitting member 2h in that it has a circuit board 27i instead of the circuit board 27h. The circuit board 27i is an FPC placed on the upper surface of the mounting board. The circuit board 27i has a base material 22h, an electrode 23i, and an insulating layer 222h.

The electrodes 23i are a pair of metal members extending in the X-axis direction, and both are arranged on the base material 22h. The electrode 23i is formed by patterning a conductor on the upper surface of the base material 22h. The electrode 23i is bonded to the base material 22h using an adhesive member. One of the electrodes 23i functions as an anode and the other functions as a cathode. The electrode 23i differs from the electrode 23h in that its end does not extend from the end E2 of the mounting board 21.

An operator who assembles the linear light emitting member 2i into the planar light emitting device 1 can grasp the portion of the base material 22h extending from the mounting board 21. Therefore, in the linear light emitting member 2i, the end portion of the base material 22h extends from the mounting board 21, thereby making it possible to improve the efficiency of incorporating the linear light emitting member 2i into the planar light emitting device 1. .

Furthermore, by bending the portion of the base material 22h extending from the mounting board 21 after the linear light emitting member 2i is incorporated into the planar light emitting device 1, the light emitted from the light emitting element 24 can be transferred to the extended portion. It functions as a light shielding member that prevents leakage from the opening of the case 17. Thereby, the linear light-emitting member 2i prevents light from leaking from the light-emitting element 24, making it possible to improve the light-emitting efficiency of the planar light-emitting device 1.

FIG. 22 is a perspective view of a planar light emitting device 1j according to the eleventh embodiment, and FIG. 23 is an exploded perspective view of the planar light emitting device 1j. The planar light emitting device 1j is used, for example, as a light source for a display device such as a liquid crystal display or a light source for a lighting device such as a ceiling light. Although the planar light emitting device 1j shown in FIGS. 22 and 23 has a flat rectangular parallelepiped shape extending in a predetermined direction, the shape of the planar light emitting device 1j is not limited to this example, and may vary depending on the application. It may be determined accordingly.

The planar light emitting device 1j includes a linear light emitting member 2j, a light guide plate 11, a reflective sheet 12j, a diffusion sheet 13, a light condensing sheet 14, a reflective polarizing plate 15, a spacer 16, and a case 17 that accommodates these inside. The case 17 can be separated into an upper case 17a and a lower case 17b. The case upper part 17a has an opening in the center, and the reflective polarizing plate 15 is exposed to the outside through the opening. Further, the lower case 17b has an opening near its end through which the power cable 18 is inserted. The power cable 18 supplies power to the linear light emitting member 2 from an external power source (not shown).

The opening of the case upper part 17a functions as a light emitting surface of the planar light emitting device 1j. Although the shape of the light emitting surface is rectangular in the examples shown in FIGS. 22 and 23, the shape of the light emitting surface is not limited to such an example, and the shape of the light emitting surface may be any polygon, ellipse, or the like.

The planar light emitting device 1j differs from the planar light emitting device 1 in that it includes a linear light emitting member 2j and a reflective sheet 12j instead of the linear light emitting member 2 and the reflective sheet 12. Below, the reflective sheet 12j and the linear light emitting member 2j will be explained.

The reflective sheet 12j is a thin film-like member provided below the light guide plate 11. The reflective sheet 12j is a metal plate, film, white sheet, or the like that reflects light. The light-reflecting film is, for example, a film on which a vapor-deposited film of silver, aluminum, or the like is formed. As the film, for example, resin such as nylon, liquid crystal polymer, polyethylene terephthalate, etc. is used. The surface of the reflective sheet 12j may be further coated with a reflective film. The reflective sheet 12j has an opening near its end through which the power cable 18 is inserted.

The reflective sheet 12j is housed in the case 17 with its end bent along the opposing surface 11d that faces the incident surface 11a (see FIG. 2) of the light guide plate 11. Thereby, the reflective sheet 12j has a main reflective part 12j-1 that covers the reflective surface 11c (see FIG. 2) of the light guide plate 11, and an opposite reflective part 12j-2 that covers the surface facing the incident surface 11a. . The main reflecting section 12j-1 and the opposing reflecting section 12j-2 may be formed as separate bodies.

FIG. 24 is a cross-sectional view of the planar light emitting device 1j. FIG. 24 is a sectional view taken along the line XXIV-XXIV in FIG. 21.

The linear light emitting member 2j is arranged along the inner side of the side surface extending in the longitudinal direction of the case 17 so that its longitudinal direction coincides with the longitudinal direction of the case 17. That is, the light guide plate 11 is arranged in the case 17 with the incident surface 11a facing the linear light emitting member 2. The linear light emitting member 2j is adhered to the case 17 with an adhesive member such as an adhesive sheet, an adhesive tape, or an adhesive. The linear light emitting member 2j may be fixed to the case 17 with a screw or a pin.

Of the light emitted from the linear light-emitting member 2j, the light that goes toward the main reflection section 12j-1 of the reflection sheet 12j (indicated by the broken line arrow L1 in FIG. 24) is reflected by the main reflection section 12j-1. The light is emitted from the emission surface 11b. Of the light emitted from the linear light-emitting member 2j, the light (indicated by the solid line arrow L2 in FIG. 24) directed toward the opposing reflecting section 12j-2 of the reflecting sheet 12j is reflected by the opposing reflecting section 12j-2. The light enters the linear light emitting member 2j again. That is, the opposing reflecting portions 12j-2 of the reflective sheet 12j reflect the light emitted from the opposing surface 11d of the light guide plate 11, which faces the incident surface 11a, to the outside of the light guide plate 11 and return it to the light guide plate 11 side.

FIG. 25 is a front view of the linear light emitting member 2j, and FIG. 26 is a sectional view of the linear light emitting member 2j. FIG. 26 is a cross-sectional view taken along the line XXVI-XXVI in FIG. 25. The linear light emitting member 2j roughly includes a mounting board 21, a circuit board 22, an electrode 23, a plurality of light emitting elements 24, a frame 25j, and a sealing material 26. The linear light emitting member 2j differs from the linear light emitting member 2 in that it has a frame 25j instead of the frame 25. In addition, in FIG. 25, the electrode 23 provided at the lower part of the frame body 25j is shown as being visible. Furthermore, hereinafter, the area of the mounting board 21 where the light emitting elements 24 are arranged will be referred to as a light emitting area. In the example shown in FIG. 25, the area of the mounting board 21 exposed through the opening of the circuit board 22 is the light emitting area. Below, the frame 25j will be explained with reference to FIG. 26.

The frame 25j is an annular member provided on the circuit board 22 so as to surround the plurality of light emitting elements 24. The frame 25l is provided so that its inner circumference substantially matches the outer circumference of the opening 221 of the circuit board 22. The frame 25 is made of a white resin that reflects light from the light emitting element 24, such as silicone resin or epoxy resin in which fine particles such as titanium oxide are dispersed.

The frame 25j has a convex portion 25j-1 on its inner peripheral surface that protrudes toward the inner side where the light emitting element 24 is arranged, that is, toward the light emitting element 24 side. The convex portion 25j-1 extends to the inside of the outer edge of the opening 221 of the circuit board 22. That is, the apex 25j-2 of the convex portion 25j-1 that protrudes inwardly is located inside the outer edge of the opening 221 of the circuit board 22. As a result, the vertex 25j-2 is located directly above the mounting board 21 exposed from the opening 221, and faces the mounting board 21 exposed from the opening of the circuit board 22.

The protrusion 25j-1 is provided integrally with the frame 25j over the entire inner peripheral surface of the frame 25j. The convex portions 25j-1 may be provided only on portions (both side portions) of the inner circumferential surface of the frame body 25j that face each other and extend in the longitudinal direction of the linear light emitting member 2j. The convex portion 25j-1 may be provided only on the portion facing the side surface of the light emitting element 24 among the portions extending in the longitudinal direction of the inner circumferential surface of the frame 25j.

As described using FIG. 24, a part of the light emitted from the linear light emitting member 2j is reflected by the opposing reflection section 12j-2 and enters the linear light emitting member 2j again. Of the light that enters the linear light emitting member 2j, the light that enters inside the apex 25j-2 of the frame 25j (indicated by arrow L3 in FIG. The light is reflected by the substrate 21 and emitted toward the light guide plate 11 again.

Of the light incident on the linear light emitting member 2j, the light incident on the outside of the vertex 25j-2 (indicated by arrow L4 in FIG. It is reflected multiple times between 25j-1 and reaches the mounting board 21. The light that has reached the mounting board 21 is reflected on the mounting board 21, repeats reflection again between the convex portions 25j-1, and is emitted toward the light guide plate 11. That is, since the frame 25j has the convex portion 25j-1, the average optical path length within the sealing material 26 of the light incident on the linear light emitting member 2j until it exits from the linear light emitting member 2j again becomes longer. . That is, the convex portion 25j-1 functions to guide a portion of the light reflected by the opposing reflective portion 12j-2 of the reflective sheet 12j into the sealant 26.

The linear light emitting member 2j emits mixed light of the blue light emitted from the light emitting element 24 and the yellow light emitted by exciting the phosphor contained in the sealant 26. If the intensity ratio of blue light and yellow light is appropriate, the mixed light will be white light.

The mixed light enters from the incident surface 11a of the light guide plate 11 and is gradually scattered by the light guide plate 11, the diffusion sheet 13, the condensing sheet 14, or the reflective polarizing plate 15 while traveling inside the light guide plate 11. Scattered light is emitted from the planar light emitting device 1. However, blue light is generally more easily scattered than yellow light. Therefore, even if the intensity ratio of the mixed light emitted from the linear light emitting member 2j is appropriate, a large amount of blue light is scattered immediately after entering the light guide plate 11, so that if the light guide plate 11 is close to the linear light emitting member 2j, the blue light is scattered. The light emitted from the part is more bluish than white light. Furthermore, the light emitted from a portion far from the linear light emitting member 2j is more yellowish than white light.

In the linear light-emitting member 2j, since the frame 25j has the convex portion 25j-1, the average optical path length of the light reflected by the opposing reflecting portion 12j-2 and incident on the linear light-emitting member 2j is increased, and the sealing More yellow phosphor contained in the material 26 is excited. As a result, yellowish light is incident on the light guide plate 11, so that the light emitted from the portion of the light guide plate 11 near the linear light emitting member 2j is prevented from becoming bluish light. On the other hand, since the light that has been reflected multiple times between the convex portions 25j-1 is attenuated, the proportion of this light reaching a portion of the light guide plate 11 far from the linear light emitting member 2j is small. Therefore, even if such light is incident, it is unlikely that the light emitted from a portion far from the linear light emitting member 2j will become more yellowish. As a result, the linear light emitting member 2j makes it possible to make the color of the light emitted from the planar light emitting device 1j uniform.

In the above description, it is assumed that the convex portion 25j-1 protrudes to the inside of the outer edge of the opening 221, but the present invention is not limited to such an example. The apex 25j-2 of the convex portion 25j-1 may be located outside the opening 221 of the circuit board 22 when viewed from above. Even in this case, since the light incident on the linear light emitting member 2j can be reflected between the convex portions 25j-1, the color of the light emitted from the planar light emitting device 1j is made uniform.

It should be understood that those skilled in the art can make various changes, substitutions, and modifications thereto without departing from the spirit and scope of the invention. The embodiments and modifications described above may be implemented in appropriate combinations within the scope of the present invention.

1 Planar light emitting device 11 Light guide plate 17 Case 2 Linear light emitting member 21 Mounting board 22 Circuit board 23 Electrode 24 Light emitting element 25 Frame

Claims (9)

a mounting board extending in a predetermined direction;
a circuit board disposed on the mounting board and extending in the predetermined direction, the circuit board having an opening extending in the predetermined direction;
an electrode arranged on the circuit board;
a plurality of light emitting elements arranged on the mounting board along the predetermined direction and electrically connected to the electrode;
a frame body arranged on the circuit board so as to surround the plurality of light emitting elements and reflecting light from the light emitting elements;
The frame has a protrusion on an inner circumferential surface that extends inward from an outer edge of the opening in the direction of the light emitting element.
A linear light-emitting member characterized by: The frame body is formed so that an elevation angle of a tangent line extending from the center of the upper surface of the light emitting element in the lateral direction of the linear light emitting member and touching the frame body is 5 degrees or more and 30 degrees or less, The linear light emitting member according to claim 1. The height of the top surface of the light emitting element substantially matches the height of the top surface of the electrode.
The linear light emitting member according to claim 1 or 2. The electrode has an extending portion extending from the inner periphery of the frame,
The linear light emitting member according to any one of claims 1 to 3, wherein the plurality of light emitting elements are electrically connected to the electrode via a wire joined to the extending portion. The circuit board has a plurality of the openings along the predetermined direction,
The electrode has an extending portion extending from the inner periphery of the frame between adjacent openings of the plurality of openings,
The linear light emitting member according to any one of claims 1 to 3, wherein the plurality of light emitting elements are electrically connected to the electrode via a wire joined to the extending portion. The linear light emitting member according to any one of claims 1 to 5, wherein the upper surface of the frame is formed in a planar shape parallel to the mounting board. The height of the circuit board is lower than at least one light emitting element among the plurality of light emitting elements.
The linear light emitting member according to any one of claims 1 to 6. a mounting board extending in a predetermined direction;
a circuit board placed on the mounting board and extending in the predetermined direction;
an electrode arranged on the circuit board;
a plurality of light emitting elements arranged on the mounting board along the predetermined direction and electrically connected to the electrode;
a frame body arranged on the circuit board so as to surround the plurality of light emitting elements and reflecting light from the light emitting elements;
The light emitting element has a directional characteristic such that the intensity of the emitted light is maximized in an emitting direction having a predetermined elevation angle in the lateral direction of the mounting board,
The frame has a protrusion on its inner peripheral surface that protrudes in the direction of the light emitting element, and a curved surface extending from the upper end of the frame to the protrusion that protrudes in the direction of the light emitting element is a curved surface that extends toward the light emitting element. formed so as to be located in the emission direction with respect to the central part of the upper surface;
A linear light-emitting member characterized by: case and
A mounting board having a light emitting region, a plurality of light emitting elements mounted in the light emitting region of the mounting board, a frame disposed around the plurality of light emitting elements, and a plurality of light emitting elements mounted inside the frame. a linear light emitting member including a sealing material and disposed along the inside of the case;
The interior of the case includes an entrance surface through which light from the linear light emitting member is incident, and an exit surface through which the light incident from the entrance surface is output, with the entrance surface facing the linear light emitting member. A light guide plate placed in the
a reflective sheet that reflects light emitted from the light guide plate from a surface facing the incident surface and returns it to the light guide plate,
The frame has a convex portion protruding toward the light emitting element in order to guide a portion of the light reflected by the reflective sheet into the sealing material.
A planar light emitting device characterized by:

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