JP4223740B2 - Light emitting device package - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a light-emitting element of a lighting device that illuminates a switch such as a liquid crystal display device and a numeric keypad in an electronic device such as a mobile phone, and particularly relates to a package that houses the light-emitting element.
[0002]
[Prior art]
A backlight for illuminating a conventional liquid crystal display device or the like has a configuration as shown in FIG. That is, the light guide plate 4 is disposed behind the liquid crystal display panel 2, and the LED elements 6 are disposed on the side of the light guide plate 4 (in some cases, disposed on the back side of the light guide plate 4).
[0003]
The LED element 6 is mounted in the reflection frame 8 in order to collect the emitted light and irradiate it into the light guide plate 4. The reflection frame 8 has high reflection efficiency such as white, and the LED element 6 is mounted on the inner side bottom portion 8a and sealed with a transparent resin or the like. The reflection frame 8 in which the LED element 6 is mounted inside has an electrode for electrically connecting the LED element 6 and the outside, and the substrate 10 is connected to the conductive pattern on the substrate 10. To be implemented.
[0004]
In the conventional backlight having the above-described configuration, the light from the LED element 6 is collected on the inner wall of the reflection frame 8 and is irradiated into the light guide plate 4 from the side end face 4 a of the light guide plate 4. Thus, the light incident on the light guide plate 4 is reflected by a narrow groove or inner surface provided at the bottom of the light guide plate 4 and is irradiated in the direction of the liquid crystal display panel 2 on the surface side. Thereby, the liquid crystal display panel 2 is illuminated from behind.
[0005]
[Problems to be solved by the invention]
As described above, in the prior art, the light from the LED element 6 is condensed using the reflection frame 8 in order to efficiently enter the light guide plate 4. However, in order to increase the incident efficiency to the light guide plate 4 as described above, the following conditions must be satisfied. That is, the height H of the opening 8b that emits light from the reflection frame 8 and the height (thickness) of the side end face 4a of the light guide plate 4 that receives light are set to be equal, and the reflection frame 8 and the light guide plate 4 are connected to each other. It was necessary to place them as close as possible. By setting and arranging in this way, all the light emitted from the reflection frame 8 can be made incident on the light guide plate 4, and the efficiency can be increased.
[0006]
However, if the height of the reflection frame 8 and the thickness of the light guide plate 4 are set to be equal, the thickness of the light guide plate 4 is set to be larger than necessary, which hinders a reduction in thickness. Further, even if the reflection frame 8 and the light guide plate 4 are brought close to each other, the distance between the light guide plate 4 and the LED element 6 cannot be made shorter than the length of the reflection frame 8. Furthermore, since there are restrictions due to the mounting accuracy of the reflection frame 8 on the substrate 10 and the positional accuracy of the light guide plate 4 and the reflection frame 8, the distance L between the light guide plate 4 and the reflection plate 8 is less than the mounting and position error. Could not set. Therefore, it is possible to make the light guide plate 4 thinner and to place the light guide plate 4 and the LED element 6 closer to each other.
[0007]
The present invention has been made in view of the above-described problems of the prior art, and provides a light-emitting element package that can increase the efficiency of light incident on a light guide plate and further reduce the thickness of a backlight unit.
[0008]
[Means for Solving the Problems]
The package for a light-emitting element according to the present invention has a main body on which the light-emitting element is mounted, and projects from the main body in a direction in which the emission surface of the light-emitting element faces to sandwich the light-emitting element from above and below. And a light guide plate insertion portion having a pair of projecting portions set so as to be substantially equal to each other, and a light guide plate having a thickness equal to or less than the height of the light emitting surface of the light emitting element. The light guide plate insertion portion causes the center portion in the thickness direction of the light guide plate and the center portion of the emission surface of the light emitting element to face each other and the light guide plate is brought close to the emission surface of the light emitting element, or It is to be held in contact. As shown in claim 2, a reflective surface is formed on a part or the entire surface of the projecting portions of the light emitting element package opposite to each other, and the reflective surface is formed from the emission surface of the light emitting element. Light is reflected toward the inside of the light guide plate inserted between the protrusions. According to a third aspect of the present invention, the reflecting surface of the light emitting device package is an inclined surface, and the inclined surface is inclined so that the distance from the end of the emitting surface of the light emitting device is reduced. Yes. According to a fourth aspect of the present invention, a transparent resin portion is provided on the reflection surface of the light emitting element package, and the surfaces of the transparent resin portions that face each other are configured as parallel planes. Further, according to a fifth aspect of the present invention, the protruding portion of the light emitting element package is made of a transparent resin or a transparent resin containing a phosphor, and a part or the entire surface of the protruding outer surface is opposed to the protruding portion. Each of the reflecting surfaces is formed to reflect light from the emitting surface of the light emitting element toward the light guide plate inserted between the projecting portions. According to a sixth aspect of the present invention, the reflecting surface of the light emitting device package is an inclined surface, and is inclined so that the distance from each other decreases toward the tip of the protruding portion. According to a seventh aspect of the present invention, the reflection surface of the light emitting element package is formed by a reflector that covers the outer surface of the protrusion. In addition, according to an eighth aspect of the present invention, the reflective surface of the light emitting element package is formed by a reflector that covers the opposing inner surfaces of the protrusions. According to a ninth aspect of the present invention, the reflecting surface of the light emitting device package is composed of a plurality of different inclined surfaces. According to a tenth aspect of the present invention, the reflection surface of the light emitting device package is formed of a reflector having a plurality of different inclined surfaces. Further, as shown in claim 11, a resin part made of a transparent resin or a transparent resin containing a phosphor is provided on the reflective surface of the light emitting element package, and the resin parts face each other. Are constituted by parallel planes. According to a twelfth aspect of the present invention, the reflective surface of the light emitting device package is formed so as to surround the light emitting device.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
The light emitting element package of the present invention has a main body on which the light emitting element is mounted and a pair of protrusions protruding from the main body. The protrusions are positioned so as to sandwich the emission surface of the light emitting element that irradiates light to the light guide plate, and are set at an interval at which the light guide plate can be inserted. In this light emitting element package, the light emitting element is mounted on the main body, and the light emitting element package is mounted on the substrate. Here, the positional relationship between the light guide plate and the light emitting element can be set by inserting the light guide plate between the protruding portions. That is, the light guide plate faces the center portion of the light emitting element and is very close to the light emitting element exit surface with the protrusion in the center in the thickness direction of the light guide plate and the center portion of the light emitting element. Held or in contact.
[0010]
In particular, the light from the emission surface of the light emitting element can be incident on the light guide plate by reflecting the surfaces of the projecting portions facing each other, and the light from the emission surface can be used efficiently without leaving any excess. Can do. At the same time, even a light guide plate having an end surface lower than the height of the exit surface (that is, a thin sheet-like light guide plate) can take in all the light from the light emitting element and guide it in the irradiation direction. The backlight unit can be significantly reduced in thickness.
[0011]
【Example】
Embodiments of the present invention will be described below with reference to the drawings. 1 is a side view showing a light emitting device package according to an embodiment of the present invention, FIG. 2 is a perspective view of the light emitting device package shown in FIG. 1, FIG. 3 is a partially cut plan view, and FIG. 4 is a partially cut side view. FIG. 5 is a perspective view showing only the main body.
[0012]
A package 12 includes a main body 12a and a light guide plate insertion portion 12b. The main body 12a has a substrate shape made of glass epoxy resin or the like, and a pair of electrode patterns 12c and 12d are formed from the front surface to the left and right side surfaces and a part of the back surface. A light-emitting element 14 such as a light-emitting diode is mounted on the facing portion of the electrode patterns 12c and 12d provided at the front center of the main body 12a.
[0013]
On the other hand, the light guide plate insertion portion 12b is made of resin and is integrally formed on the front surface of the main body 12a. The light guide plate insertion portion 12b protrudes in a direction in which the emission surface 14a of the light emitting element 14 that irradiates light to the light guide plate 16 faces, that is, in a direction perpendicular to the front surface of the main body 12a, and sandwiches the light emitting element 14 from above and below. Has protrusions 12e and 12f. The protrusions 12e and 12f are set at intervals at which the light guide plate 16 can be inserted. That is, the interval between the projecting portions 12 e and 12 f is set to be substantially equal to the thickness of the light guide plate 16. Further, in the light guide plate insertion portion 12b in the present embodiment, the electrode patterns 12c and 12d on the front surface of the main body 12a and a part of the light emitting element 14 are covered to the base portions of the protrusions 12e and 12f and fixed to the main body 12a. A fixing portion 12g is provided.
[0014]
The light emitting device package 12 having the above configuration is used as follows. As shown in FIGS. 1 and 6, the light emitting element package 12 is placed on a predetermined conductive pattern on the surface of the substrate 20 so that the protruding portions 12 e and 12 f are arranged in parallel to the substrate 20. Then, the electrode patterns 12c and 12d formed from the side surface to the back surface of the main body 12a are fixed to the conductive pattern of the substrate 20 with the solder 22 and connected. After mounting the light emitting element package 12 on the substrate 20 in this way, the light guide plate 16 is inserted between the projecting portions 12e and 12f.
[0015]
The light guide plate 16 inserted between the projecting portions 12e and 12f does not become inaccessible to the light emitting element 14 by abutting against the end portion of the package as in the conventional reflection frame described above. Accordingly, the side end face of the light guide plate 16 is held in a state in which the central portion in the thickness direction and the central portion of the light emitting surface 14a of the light emitting element 14 face each other and are very close to the light emitting surface 14a. It will be positioned at the optimal position. For this reason, the light emitted from the light emitting element 14 is irradiated into the light guide plate 16 from the side end face of the light guide plate 16 with high efficiency without being left behind. Then, the light incident on the light guide plate 16 is reflected by grooves and irregularities provided on the inner bottom surface of the light guide plate 16 and irradiated toward the upper liquid crystal display panel 18 to illuminate the liquid crystal display panel 18 from behind. It will be.
[0016]
In the above embodiment, as shown in FIG. 1, since the thickness of the light guide plate 16 and the height of the emission surface of the light emitting element 14 are substantially equal, almost all the light emitted from the light emitting element 14 is from the side end surface of the light guide plate 16. The light enters the light guide plate 16. However, in the case of the thinner light guide plate 16, the height of the exit surface of the light emitting element 14 is higher than the thickness of the light guide plate 16, and light from the upper and lower ends of the exit surface of the light emitting element 14 is transmitted through the light guide plate 16. Can not be taken in, the efficiency is reduced. In such a case, as shown in FIG. 7, reflecting surfaces 12h and 12i made of inclined surfaces are formed on part or all of the opposing surfaces of the protrusions 12e and 12f. The reflection surfaces 12h and 12i are inclined so that the distance between the reflection surfaces 12h and 12i decreases from the end surface of the emission surface of the light emitting element 14 toward the tips of the projecting portions 12e and 12f. In addition, the reflection surfaces 12h and 12i are improved in reflection efficiency by being mirror-finished, painted white, or subjected to metal deposition.
[0017]
By providing such reflection surfaces 12h and 12i on the protrusions 12e and 12f, the light irradiated from the upper and lower ends of the emission surface of the light emitting element 14 is reflected by the reflection surfaces 12h and 12i and is reflected on the light guide plate 16. The light enters the light guide plate 16 from the lower surface.
[0018]
Further, as shown in FIG. 7, it is desirable to provide transparent resin portions 12j and 12k on the reflecting surfaces 12h and 12i made of inclined surfaces. The transparent resin portions 12 j and 12 k are formed so that the surfaces facing each other are parallel planes, and the distance between the transparent resin portions 12 j and 12 k is equal to the thickness of the light guide plate 16. By providing such transparent resin portions 12j and 12k, the end portion of the light guide plate 16 can be reliably held without a gap between the protruding portions 12e and 12f. Thereby, the positional relationship between the light emitting element 14 and the end of the light guide plate 16 can be kept constant.
[0019]
In addition, although it is preferable to comprise the reflective surfaces 12h and 12i with an inclined surface as shown in FIG. 7, you may comprise with a parallel surface as shown in FIG.
[0020]
On the other hand, the light emitting element package 12 in the above embodiment is formed by fixing or integrally molding the light guide plate insertion portion 12b to the main body 12a. When forming the light guide plate insertion portion 12b integrally with the main body 12a, when the shape of the protrusions 12e, 12f is formed from the beginning with a mold, a rectangular parallelepiped resin portion is integrally formed with the main body 12a, Thereafter, a groove portion between the projecting portions 12e and 12f may be formed by dicing or the like. When the former mold is used, the projecting portions 12e and 12f can be formed in one step. When the latter groove portion is formed later, the interval between the projecting portions 12e and 12f can be accurately set. Can be set. Further, when the latter groove portion is formed later, a thin resin remains on the surface of the light emitting element 14 due to the manufacturing method when the groove portion is formed. Even if such a thin resin remains, the surface of the light-emitting element 14 can be protected by the resin layer and does not need to be removed in particular. It is also possible to form the main body 12a and the light guide plate insertion portion 12b as an integral part from the beginning. In this case, a lead frame is used in place of the electrode patterns 12c and 12d, the light emitting element 14 is mounted on the lead frame, and the main body 12a and the light guide plate insertion portion 12b are integrally formed around it.
[0021]
In addition, when the light guide plate insertion portion 12b is fixed to the main body 12a, as shown in FIG. 9, an upper fixing portion 12m protruding in the rearward direction may be provided at the upper end of the fixing portion 12g of the light guide plate insertion portion 12b. . By providing the upper fixing portion 12m, the fixing area can be increased by fixing the upper fixing portion 12m to the upper surface of the main body 12a, thereby increasing the fixing force. Further, as shown in FIG. 10, substantially L-shaped projections 12n and 12p are provided at the upper end of the fixing portion 12g so as to hold the main body 12a from the side surface to the back surface, and the main body 12a is held by the protrusions 12n and 12p. Or you may comprise so that it may adhere. In any structure, the upper fixing portion 12m and the protrusion 12n are not covered with the upper fixing portion 12m and the protrusions 12n and 12p below the electrode patterns 12c and 12d provided on the side surface and the back surface of the main body 12a. , 12p are positioned. Thereby, the part which solders electrode pattern 12c, 12d can be ensured under electrode pattern 12c, 12d.
[0022]
2 and 3 form the left and right portions of the light-emitting element 14 (portions connecting the protrusions 12e and 12f) if the protrusions 12e and 12f are securely fixed to or integrated with the main body 12a. It is not necessary. Further, when the fixing portion 12g is formed, if the thickness in the front direction is set to be slightly larger than the thickness of the light emitting element 14, the light guide plate 16 is inserted between the protruding portions 12e and 12f. In addition, the side end face of the light guide plate 16 abuts against the fixing portions 12g on the left and right sides of the light emitting element 14 before the light emitting element 14, so that the light emitting element 14 can be prevented from being damaged.
[0023]
FIG. 11 is a cross-sectional view showing a modified example in which the reflecting surface is formed along the outer shape of the protruding portion, and FIG. 12 is a perspective view thereof. The protrusions 12e and 12f shown in FIGS. 11 and 12 are made of a transparent resin or a transparent resin containing a phosphor. Reflecting surfaces 12r and 12s are provided on the outer surfaces of the projecting portions 12e and 12f respectively opposed to the front and back surfaces of the light guide plate 16 inserted into the light guide plate insertion portion 12b. The reflecting surfaces 12r and 12s are inclined surfaces that are inclined so that the distance between the reflecting surfaces 12r and 12s decreases from the vicinity of the light emitting element 14 toward the tips of the protruding portions 12e and 12f. On this inclined surface, a metal film or a white paint film is formed by vapor deposition, plating, painting, or the like, and a reflecting body 24 such as a metal plate is fixed, so that the reflection efficiency is increased and the reflecting surfaces 12r and 12s are formed. Has been. With such a configuration, the outer shape of the package can be further reduced, and the reflective surface can be easily formed. Moreover, the wavelength of the light emitted from the light emitting element 14 can be changed by the phosphors included in the protrusions 12e and 12f, and the light guide plate 16 can be irradiated with light having a wavelength more effective as illumination.
[0024]
Further, not only the inclined surfaces of the protrusions 12e and 12f but also the side surfaces 12t and 12u are all covered with a metal film, a white coating film, or a reflector, so that the light emitting element 14 can be surrounded by the reflecting surface. By surrounding the light emitting element 14 with the reflection surface in this manner, light emitted from the light emitting element 14 in a direction other than the light guide plate 16 can be taken into the light guide plate 16, and the incident efficiency to the light guide plate 16 can be further increased. It becomes possible.
[0025]
FIG. 13 is a cross-sectional view showing a modified example in which the inner surface of the light guide plate insertion portion is formed by a combination of a plurality of surfaces and a reflective surface is formed thereon, and FIG. 14 is a cross-sectional perspective view thereof. As shown in FIGS. 13 and 14, the inner surfaces of the projecting portions 12 e and 12 f facing each other are formed at the inner end portion in the vicinity of the main body 12 a on which the light emitting element 14 is mounted and are the inner peripheral surface of the cylinder or the side surface of the truncated cone. The reflective surfaces 12v and 12w are formed of circumferential surfaces that are inclined so that the diameters are slightly expanded toward the tips of the projecting portions 12e and 12f, and the projecting portions 12e are formed at the center portion and like the side surfaces of the truncated cone. , 12f are configured by reflecting surfaces 12x, 12y made of circumferential surfaces inclined so that their diameters become narrower toward the tips, and guide holding surfaces 12z, 12zz made of parallel planes formed at the tips. On the inner surface composed of such a surface configuration, a metal film, a white coating film or the like is formed by vapor deposition, plating, painting, or the like, and the reflection efficiency is increased by fixing the reflector 24 such as a metal plate, Reflective surfaces 12v, 12w, 12x, and 12y are formed. The guide holding surfaces 12z and 12zz guide and hold the light guide plate 16 inserted between them, and are set at intervals corresponding to the thickness of the light guide plate 16.
[0026]
In the light emitting element package, light from the light emitting element 14 is directly incident on the light guide plate 16 from the end face of the light guide plate 16 inserted in the light guide plate insertion portion 12b, and the reflecting surfaces 12v, 12w, 12x, 12y. And is incident on the light guide plate 16 from the front and back surfaces of the light guide plate 16. Thereby, almost all of the light from the light emitting element 14 enters the light guide plate 16, and the incident efficiency can be improved.
[0027]
Further, in the light emitting element package shown in FIGS. 13 and 14, as shown in FIGS. 15 and 16, a transparent resin or a transparent resin containing a phosphor is used on the reflective surfaces 12v, 12w, 12x, and 12y. The resin portions 12jj and 12kk may be formed to increase the light transmission efficiency.
[0028]
The reflective surfaces 12v, 12w, 12x, and 12y may be formed by insert-molding the reflector 24 formed in the shape of the reflective surface in advance when the projecting portions 12e and 12f are molded with resin. Can be easily formed.
[0029]
【The invention's effect】
According to the present invention, since the light guide plate is inserted between the pair of protrusions provided in the light guide plate insertion portion, the light emitting element mounted on the central portion and the main body in the thickness direction of the inserted light guide plate The light guide plate can be faced in a state where it is aligned with the central portion of the light emitting surface of the light emitting device, and the light guide plate can be held very close to or in contact with the light emitting surface of the light emitting element. Can be set in an optimum state, and the light incident efficiency to the light guide plate can be increased and the light guide plate can be made thin.
[0030]
In addition, by forming an inclined surface on the opposing surface of the protruding portion, even when a light guide plate thinner than the height of the emitting surface of the light emitting element is used, the light from the emitting surface is reflected by an inclined surface or the like. All of the light can be incident on the light guide plate by being reflected by the surface. For this reason, even if it is a case where a thin light-guide plate is used, it can illuminate efficiently and can thin the light-guide plate and can make the whole illuminating device thin.
[Brief description of the drawings]
FIG. 1 is a side view showing a light emitting device package according to an embodiment of the present invention.
2 is a perspective view of the light emitting device package shown in FIG. 1. FIG.
FIG. 3 is a partially cut plan view of the light emitting device package shown in FIG. 1;
4 is a cross-sectional view of the light-emitting element package shown in FIG.
5 is a perspective view showing only the main body of the light emitting device package shown in FIG. 1; FIG.
6 is a perspective view showing a state in which the light emitting device package shown in FIG. 1 is mounted and a light guide plate is inserted. FIG.
7 is a cross-sectional view showing a modified example in which a reflection surface made of an inclined surface is provided on the protruding portion of the light emitting element package shown in FIG. 4;
FIG. 8 is a cross-sectional view showing a modified example in which the reflecting surface shown in FIG. 7 is formed in parallel planes.
FIG. 9 is a perspective view showing a modification in which an upper fixing portion is provided in the light emitting element package shown in FIG. 2;
10 is a perspective view showing a modified example in which protrusions are provided on the light emitting element package shown in FIG. 2. FIG.
11 is a cross-sectional view showing a modified example in which a reflective surface is provided on the outer surface of the light emitting device package shown in FIG. 2;
12 is a perspective view of the light emitting device package shown in FIG. 11. FIG.
13 is a cross-sectional view showing a modified example in which the reflecting surface of the light emitting element package shown in FIG. 7 is configured by a plurality of surfaces.
14 is a cross-sectional perspective view of the light emitting device package shown in FIG.
15 is a cross-sectional view showing a modified example in which a resin portion is provided on the reflecting surface shown in FIG.
16 is a cross-sectional perspective view of the light emitting device package shown in FIG.
FIG. 17 is a side view showing the structure of a conventional backlight.
[Explanation of symbols]
2, 18 Liquid crystal display panels 4, 16 Light guide plate 10, 20 Substrate 12 Light emitting device package 12a Main body 12b Light guide plate insertion portion 12c, 12d Electrode pattern 12e, 12f Projection portion 12g Fixing portion 12h, 12i Reflective surface 12j, 12k Transparent resin Part 12jj, 12kk resin part 12r, 12s reflecting surface 12v, 12w, 12x, 12y reflecting surface 14 light emitting element 14a emitting surface

Claims (12)

A body on which the light emitting element is mounted;
The light emitting element protrudes from the main body in a direction facing the light emitting element, and is integrally formed on the front surface of the main body so as to sandwich the light emitting element from above and below, and has a thickness equal to or less than the height of the light emitting element. A light guide plate insertion portion having a pair of protrusions set so that the distance between the optical plate and the optical plate is substantially equal ,
The light guide plate insertion portion causes the central portion in the thickness direction of the light guide plate and the central portion of the light emitting surface of the light emitting element to face each other, and the light guide plate is brought close to or in contact with the light emitting device. A package for a light-emitting element, which is held in a state of being held. Reflective surfaces are formed on the inner surfaces of the protrusions facing each other, either partially or entirely, and the reflection surfaces are inserted into the light guide plate into which light from the emission surface of the light emitting element is inserted between the protrusions. The light-emitting element package according to claim 1, wherein the light-emitting element package is reflected toward the surface. 3. The light emitting device package according to claim 2, wherein the reflecting surface is formed of an inclined surface, and the inclined surface is inclined so that a distance from each other is narrowed from an end portion of the emitting surface of the light emitting device. 4. The light emitting device package according to claim 2, wherein a transparent resin portion is provided on the reflecting surface, and the transparent resin portions are formed of planes parallel to each other. The projecting portion is made of a transparent resin or a transparent resin containing a phosphor, and a reflective surface is formed on a part or the entire surface of the outer surface of the projecting portion, the reflecting surface of the light emitting element. The light emitting device package according to claim 1, wherein light from an emission surface is reflected toward the light guide plate inserted between the projecting portions. 6. The light emitting device package according to claim 5, wherein the reflecting surface is an inclined surface, and is inclined so that a distance from each other decreases toward a tip of the protruding portion. The light emitting element package according to claim 5 or 6, wherein the reflective surface is formed of a reflector that covers an outer surface of the protruding portion. 3. The light emitting device package according to claim 2, wherein the reflective surface is formed of a reflector that covers the opposing inner surfaces of the protrusions. The light-emitting element package according to claim 2, wherein the reflection surface includes a plurality of different inclined surfaces. 3. The light emitting device package according to claim 2, wherein the reflection surface is formed of a reflector having a plurality of different inclined surfaces. The resin portion made of a transparent resin or a transparent resin containing a phosphor is provided on the reflection surface, and the resin portions are configured by planes parallel to each other. The package for light emitting elements of 9 or 10. 12. The light emitting device package according to claim 9, 10 or 11, wherein the reflecting surface is formed so as to surround the light emitting device.

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