JP2012227536A - Led light source and luminous body using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an inexpensive LED light source having large luminous flux, a thin shape, and high side radiation intensity.SOLUTION: An LED light source comprises: an LED package part 6 mounting at least one LED chip 3 on a heat dissipation substrate 1 where the LED chip 3 is sealed with sealing resin 5 that is translucent material; and a lens 7 which is arranged on the LED package part 6 to increase the thickness toward a portion immediately above each LED chip 3, and a recess part 8 recessed to the LED chip 3 side is formed near such a portion.

Description

  The present invention relates to a light emitting source applicable to various applications using a light emitting diode (LED) and a light emitting body such as a liquid crystal backlight, a lighting fixture, and a sign / advertisement lamp using the light source.

  Many LED light source structures such as an LED package having an optical lens have been invented so far. Among them, some proposals have been made on a lens and a light source structure that emit strong light (side radiation distribution) in a direction along the installation surface of the LED light source, that is, a side surface direction of the light source. For example, for an LED lens, a lens cap, and a light emitting device using the lens, a first refraction angle that is inclined with respect to the central axis of the lens, and a smooth curved surface from the bottom surface to the first refraction surface There is one in which side radiation is obtained by a lens shape having a second refracting surface extending as described above (for example, Patent Document 1).

JP 2004-133391 A

  When the light-emitting device of Document 1 designed with the LED chip as a point light source is suitable for a high-output light source (a large radiant flux or a large luminous flux), a plurality of LED chips (for example, in recent years have been widely used). A 1W class large LED chip having a surface area of 1 mm × 1 mm per unit) may be concentrated in the center of the package. However, in order to produce a light distribution effect using the characteristic lens shape of Document 1, a lens diameter that is large enough to surround the light source is required, and the area occupied by the light source is about as large as possible. It is essential to increase the lens thickness so that it is proportional.

  In the case of using a lens in which the vertical direction of the lens is compressed with the lens shape of the above-mentioned document 1 for the purpose of thinning, the reflection effect including total reflection on the lens surface is weakened along with the thinning. Therefore, the side light distribution control function (side radiation distribution) is greatly lost, and the luminous flux ratio in the front direction of the light emitting device (the direction along the central axis) increases. In addition, as the concentrated light source output at the center of the package increases, it becomes necessary to secure heat resistance as well as heat dissipation, so it is difficult to extremely reduce the thickness of this portion.

Further, in the case of using a plurality of large LED chips, an arrangement in which the arrangement intervals of the respective LED chips are widened is considered in order to suppress an increase in LED chip temperature that causes a decrease in light emission efficiency and a shortening of the lifetime. In that case, the area occupied by the LED chip will increase, so if you want to maintain the side emission characteristics, the lens size (diameter, thickness) must also be increased proportionally. It is difficult to plan. Furthermore, since the LED chip itself has a certain amount of diffused light distribution characteristics, the diffused light inside the lens shape increases as the lens volume increases, resulting in a reduction in the refraction / reflection control effect on the lens surface. Become. Further, considering the lens molding surface, it is not easy to provide a concavo-convex shape on the side surface, and the production cost during mass production is unavoidable.
From the above, it can be said that with the configuration of the above-mentioned document 1, it is very difficult to cope with thinning / compactness while maintaining the side radiation distribution under the condition that the total surface area of the LED chip is increased.

  The present invention solves the above problems, obtains a large luminous flux (large electric input), a thin, high side emission intensity, and an inexpensive LED light source, and a thin large luminous flux with good luminous efficiency using the same. It is to obtain a luminous body.

  The LED light source according to the present invention includes an LED package unit in which at least one LED chip is mounted on a heat dissipation substrate, the LED chip is sealed with a light-transmitting material, and the LED package unit is disposed on the LED package unit, A lens formed with a concave portion recessed on the LED chip side immediately above each LED chip, wherein the lens has an inverted cone having a vertex angle substantially on the central axis of the LED chip or It has an inverted polygonal pyramid shape, and has a curved shape in which the thickness of the lens gradually decreases from the start end of the concave portion toward the outer peripheral end of the lens.

  According to the present invention, the light emitted from the LED chip is spread to the side of the lens by the recess formed in the upper part of the lens, and the light is efficiently propagated to the periphery of the lens, thereby increasing the side emission component around the lens. it can. Further, when a plurality of LED chips are used, they are scattered in the mounting area of the heat dissipating substrate, and are mounted and arranged at a distance from each other, thereby improving the heat dissipating property and preventing the deterioration of the LED chip performance. Therefore, even in a large input power LED light source using a plurality of large LED chips for the purpose of a large luminous flux or a large radiant flux, a thin LED light source with high side emission intensity can be obtained while suppressing the LED chip temperature rise.

(A) It is a top view of the LED light source which concerns on Embodiment 1. FIG. (B) It is side sectional drawing of Fig.1 (a). It is explanatory drawing explaining the effect | action of the recessed part of the lens of the LED light source of FIG. FIG. 6 is a side sectional view showing a modification of the LED light source according to Embodiment 1. FIG. 6 is a side sectional view showing another modification of the LED light source according to Embodiment 1. (A) It is a top view of another LED light source which concerns on Embodiment 1. FIG. (B) It is side sectional drawing of Fig.5 (a). (A) It is a simulation model of the LED light source of Embodiment 1. FIG. (B) It is a light distribution characteristic view of Drawing 6 (a). (A) It is the simulation model of the other LED light source of Embodiment 1. FIG. (B) It is a light distribution characteristic figure of Drawing 7 (a). (A) It is a top view which shows the modification of the LED light source which concerns on Embodiment 1. FIG. (B) It is a top view which shows another modification of the LED light source which concerns on Embodiment 1. FIG. (C) It is a top view which shows another modification of the LED light source which concerns on Embodiment 1. FIG. (D) It is a top view which shows another modification of the LED light source which concerns on Embodiment 1. FIG. (E) It is a top view which shows another modification of the LED light source which concerns on Embodiment 1. FIG. (A) It is a top view of the LED light source which concerns on Embodiment 2. FIG. (B) It is an illustration figure of the side cross section of Fig.9 (a). (C) It is an illustration figure of the side cross section of Fig.9 (a). (A) It is a top view of the LED light source which concerns on Embodiment 3. FIG. (B) It is an illustration figure of the side cross section of Fig.10 (a). (C) It is an illustration figure of the side cross section of Fig.10 (a). (A) It is an upper side figure of another LED light source which concerns on Embodiment 3. FIG. (B) It is an illustration figure of the side cross section of Fig.11 (a). (C) It is an illustration figure of the side cross section of Fig.11 (a). (D) It is an illustration figure of the side cross section of Fig.11 (a). (E) It is a figure which shows the lens of FIG.11 (d). (A) It is a top view of the planar light-emitting body based on Embodiment 4 using an LED light source. (B) It is a side view of Fig.12 (a). It is a cross-section figure of the planar light-emitting body which concerns on Embodiment 4 using an LED light source. It is a top view of the LED light source which concerns on Embodiment 4 using an LED light source. (A) It is a cross-section figure of the LED light source which concerns on Embodiment 4 using an LED light source. (B) It is another cross-section figure of the LED light source which concerns on Embodiment 4 using an LED light source. (A) It is a top view which shows the other Example of the LED light source of this invention. (B) It is sectional drawing of the AA line part of Fig.16 (a). (A) It is a simulation model of the LED light source corresponding to FIG. 16 (with a dam material). (B) It is a light distribution characteristic view of Drawing 17 (a). (A) It is the simulation model of the LED light source corresponding to FIG. 16 (no dam material). (B) It is a light distribution characteristic figure of Drawing 18 (a). (A) It is a top view which shows the other Example of the LED light source of this invention. (B) It is sectional drawing of the AA line part of Fig.19 (a). (A) It is a top view which shows the other Example of the LED light source of this invention. (B) It is a cross-sectional illustration figure of the AA line part of Fig.20 (a). (C) It is a cross-sectional illustration figure of the AA line part of Fig.20 (a). (D) It is a cross-sectional illustration figure of the AA line part of Fig.20 (a). (A) It is a simulation model of the LED light source of Embodiment 4. FIG. (B) It is a light distribution characteristic view of Drawing 21 (a). (A) It is a simulation model of the LED light source of Embodiment 4. FIG. (B) It is a light distribution characteristic view of Drawing 22 (a). (A) It is a simulation model of the LED light source of Embodiment 4. FIG. (B) It is a light distribution characteristic view of Drawing 23 (a). (E) It is a top view which shows the other Example of the LED light source of this invention. (F) It is sectional drawing of the AA line part of FIG.24 (e). (A) It is a simulation model of the LED light source of Embodiment 4. FIG. (B) It is a light distribution characteristic view of Drawing 25 (a). FIG. 10 is a side sectional view showing another modification of the light emitter according to the fourth embodiment. FIG. 10 is a side sectional view showing another modification of the light emitter according to the fourth embodiment. FIG. 10 is a side sectional view showing another modification of the light emitter according to the fourth embodiment. FIG. 10 is a side sectional view showing another modification of the light emitter according to the fourth embodiment.

Embodiment 1 FIG.
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1A is a top view of the LED light source according to Embodiment 1 of the present invention, and FIG. 1B is a cross-sectional view taken along line AA of FIG. The LED light source includes an LED package unit 6 having a heat dissipating substrate 1, which is an LED mounting substrate, a dam material 2, an LED chip 3, a fluorescent material 4, and a translucent sealing resin (translucent resin) 5. And a lens 7 provided on the upper portion of the LED package section 6. At least one LED chip 3 is mounted on the heat dissipating substrate 1, and a fluorescent material 4 having a wavelength conversion function of exciting and emitting light by the emission wavelength of the LED chip 3 is provided on the upper surface thereof. A dam material 2 is disposed around the LED chip 3, and the inside of the dam material 2 (a portion surrounded by the dam material) is filled with a light-transmitting sealing resin 5 to cover the LED chip 3. Protection and improvement of light extraction amount. The fluorescent material 4 is provided as necessary as will be described later.

  The heat dissipating substrate 1 is made of a metal material such as copper or aluminum having high thermal conductivity, or a ceramic material in order to make it thin and have high heat dissipating characteristics, and is insulated from the LED chip 3 as necessary. It is formed so as to have an insulating layer and a surface reflecting layer that maintain the resistance. In the present embodiment, the heat radiating substrate 1 is mainly made of a thin copper material. In FIG. 1, in order to avoid complication, an adhesive layer that is a fixing material of the LED chip 3 on the heat dissipation substrate 1, a wiring pattern that forms an electric circuit between the outside and the LED chip 3, and a metal wire or metal for that purpose Members such as bumps are omitted.

  The dam material 2 prevents the sealing resin 5 from flowing during manufacture, and is made of a resin, a metal material, or the like. Further, the dam material 2 may be made of the same material as the heat dissipating substrate 1. Further, when the dam material 2 is provided with a reflection or light distribution control function as a reflector, its surface is formed of a mirror surface or a diffusive highly reflective material. The inner surface of the dam material 2 and the surface of the heat-dissipating substrate 1 surrounded by the dam material 2 (hereinafter referred to as “cavity”) are mirror surfaces with high reflectivity, and the other surface of the dam material 2 is a highly reflective diffusion part.

  The LED chip 3 is, for example, an LED chip that emits light from bluish purple to blue, and the fluorescent material 4 is made of a material that emits a light color including yellow that absorbs the emission wavelength. And it is possible to set it as a white light-emitting light source by adjusting the quantity of the fluorescent material 4, and this Embodiment is set as the structural example which obtains the large luminous flux white light source by such a structure. Even when the fluorescent material 4 is not used, the effect of the present invention can be obtained as a large radiant flux LED light source that emits the emission color of the LED chip 3.

  The LED light source of FIG. 1 uses four large LED chips 3 (each having a surface of about 1 mm × 1 mm, about 1 W) to obtain an LED light source with a large luminous flux. Then, these LED chips 3 are not densely arranged in the center, but are scattered in the mounting region (cavity) of the heat-radiating substrate 1, and are mounted and arranged with a space therebetween. That is, in FIG. 1, four LED chips 3 are arranged on the cavity of the heat dissipation substrate 1 in a ring shape at substantially equal intervals. This is because when the LED chip 3 is centrally arranged at the center of the heat-dissipating substrate 1, the temperature is likely to rise due to the heat effect between the LED chips, and the area density of the heat generation directly under the heat-dissipating substrate 1 is very high. Will become bigger. Furthermore, the LED chip 3 has the property that the light emission efficiency decreases as the temperature rises as a basic characteristic, and the peripheral components of the LED chip 3 including the sealing resin 5 and the paste material also rise in temperature and the deterioration rate tends to increase. is there. Therefore, even when there is a restriction on the size of the LED light source, if a large input power (a large luminous flux) is required, it is possible to increase the temperature of the LED chip 3 as much as possible as described above. It becomes advantageous for suppression of.

  On the other hand, when four LED chips 3 are concentrated and arranged for the lens of Patent Document 1 described above, a large LED chip requires a concentrated arrangement area of about 3 × 3 mm. Accordingly, the thickness of the lens 7 and the thickness of the device including the package base 6 are correspondingly thick, and it is difficult to realize a reduction in thickness of, for example, a total thickness of 2 mm or less that is to be realized in the present invention.

  The lens 7 is disposed on the LED package part 6 and has a curved shape in which the thickness gradually increases toward the upper part of each LED chip 3. The lens 7 has a concave part 8 recessed toward the LED chip 3 side. It was configured as follows. The recess 8 preferably has a shape in which the space cross-sectional area inside the recess gradually decreases toward the LED chip 3, and in Embodiment 1, the shape is an inverted conical shape. The shape of the recess 8 may be a shape such as a cylinder, a polygonal column, or an inverted polygonal pyramid as long as the side radiation characteristic of light from the LED chip 3 is improved. By providing such a recess 8 in the lens 7, the light traveling in the central axis direction of the LED package part 6 can be effectively changed in the side surface direction of the LED package part 6. That is, as shown in FIG. 2, the light beam from the LED chip 3 that travels upward in the center of the LED chip 3 is the total reflection component according to Snell's law on the inverted conical surface 8 a of the recess 8 (the slope of the recess 8). Therefore, the reflection component including will travel sideways. Furthermore, the light travels to the periphery of the lens due to total reflection on the curved surface of the lens 7, part of the light is emitted from the periphery of the lens 7 as it is, and part of the light travels due to the surface reflection state of the dam material 2. Change to the surface side of the lens 7. The gentle curved shape of the lens 7 can secure a wide light guide path without greatly changing the total reflection angle, and can enhance the light guide effect to the periphery of the lens 7 as compared with the case where the lens 7 is a flat surface. It has become.

  Further, the lens 7 of FIG. 1 has four curved surfaces corresponding to the four LED chips 3 on the surface, and has a surface shape with lines intersecting each curved surface. The central depression 7 also serves to suppress the intensity of light that is intended to radiate from the cavity surface center to the center of the LED light source, including internal reflection of the LED package 6.

  With the configuration as described above, the light can be effectively spread laterally by the concave portion 8 of the lens 7, and the light can be efficiently propagated to the periphery of the lens, thereby increasing the side emission components around the lens. Therefore, by the LED chip arrangement considering the heat dissipation as described above and the lens shape corresponding to the LED chip arrangement, it is possible to obtain an LED light source having good heat dissipation of the LED chip 3 and having a large light output with a high side emission component. it can.

  The lens 7 can be formed of a resin material suitable for the purpose, such as polycarbonate, epoxy, or silicone. In addition, when using a silicone resin whose weather resistance has been improved in recent years, it can be formed from soft to hard materials with n = 1.41 to n = 1.53. In the configuration of FIG. 1, for example, the sealing resin 5 is made of soft translucent silicone, and the surface lens 7 is made of hard silicone having a good light extraction property and strong against external impact and having a higher refractive index than soft. At that time, from the viewpoint of light extraction efficiency, the sealing resin 5 and the lens 7 are brought into close contact with each other so that an air layer does not enter the intermediate layer between the sealing resin 5 and the lens 7 or another soft silicone material is interposed. It is good also as such a structure. Further, the sealing resin 5 and the lens 7 may be formed of the same material by a method such as overmolding.

  FIG. 2 is an explanatory view for explaining the operation of the concave portion 8 of the lens of the LED light source of FIG. As shown in FIG. 2, when θ is 1/2 of the apex angle of the inverted conical recess, θ is set to be a total reflection angle determined by the lens refractive index n and the peripheral medium n0 or an angle close thereto. For example, when n0 = 1 (air), n = 1.41, θ = 45 °, n = 1.53, and θ = 41 °. With such a configuration, the LED chip 3 (when the fluorescent material 4 is present) A considerable amount of light radiated from the surface of the conical surface of the concave portion 8 changes its direction to the side surface of the LED light source according to Snell's law. . In order to enhance the effect, it is necessary that the concave portion 8 constituting the inverted conical shape has a certain size. Therefore, by configuring the recess 8 so that the start end (notch end) diameter is equal to or larger than the diagonal dimension of the LED chip 3, the above-mentioned reverse is applied to at least light traveling from the LED chip 3 in the vertical direction of the LED light source. It becomes possible to enter the cone-shaped inclined surface.

  With this configuration, it is possible to increase the amount of total reflection components on the inverted conical surface of the concave portion 8 of the light emitted from the LED chip 3, and as a result, effectively spread the light in the side surface direction of the lens 7. Is possible. The effect of the above configuration can be obtained even when the shape of the concave portion 8 is an inverted polygonal pyramid. If the apex angle and the size of the inverted conical cut shape of the surface of the lens 7 are configured substantially the same as the case of the inverted cone. Good. Further, in this embodiment, the inverted conical notch end of the curved surface of the lens 7 is configured to have an angle. However, the portion of this angle has a gently curved surface that continuously changes from the concave inner surface to the curved surface. In addition, the apex of the inverted cone of the recess 8 may be rounded.

  FIG. 3 is a side sectional view showing a modification of the LED light source according to Embodiment 1 of the present invention. As shown in FIG. 3, by forming the surface of the recess 8 with the reflecting member 10, the light directly radiated from the recess 8 can be eliminated, and the light can be controlled in the direction of the side surface of the recess 8. The reflecting member 10 may be a thin film or paint, and is preferably configured as a highly reflective mirror surface or diffusing surface in order to maintain high luminous efficiency.

Further, FIG. 3 shows that the width of the lens 7 is made wider than that of the dam material 2, that is, the lens 7 is formed so that the outer peripheral portion of the lens 7 protrudes from the outer peripheral end of the LED package portion 6. By comprising in this way, light is radiated from the back surface (dam material 2 side) of the part which protruded from the edge part of the dam material 2 of the lens 7 intentionally, The light was used for the light of this invention It can be used effectively in the external application installation space.
Furthermore, as shown in FIG. 4, resin sealing is performed by a processing method of sealing without providing a dam material, and the lens bottom area is set larger than the sealing region, so that the LED chip 3 emits laterally. Light can be directly used through the sealing resin 5. Some of the light exiting from the sealing resin 5 passes upward through the lens, but a part of the light is reflected by the surface of the lens 7 and can be used as light directed toward the side or back. It is.
3 and 4 show the configuration in which the concave member 8 includes the reflecting member 10, but the configuration without the reflection member 10 still has the effect of increasing the amount of light emitted from the side of the light source to the lower portion.

  In addition, as shown in FIG. 1, when the connection portion of the outer peripheral edge of the lens 7 corresponding to each LED chip 3 is recessed in the center direction of the package portion 6, the light distribution to the side of the package portion 6 is achieved. May cause great strength. Therefore, for example, as shown in FIG. 5, a lens-shaped translucent member having a radius not less than the maximum length from the center of the package portion 6 of the lens 7 to the peripheral portion of the lens 7 is used as the lens peripheral light distribution countermeasure portion 9. It was provided as a structure to have on the back of the. With this configuration, it is possible to reduce the intensity of light distribution toward the side of the package unit 6, which is useful when the application side to be applied requires uniformity of the light distribution intensity.

  Below, the LED light source corresponding to Embodiment 1 is modeled with a commercially available light analysis simulator, and the light distribution trial calculation result is shown. FIGS. 6 and 7 are (a) perspective external views and (b) light distribution trial calculation results of a model created under the condition that the total height of the LED light source is 2 mm, which is intended to reduce the thickness of the present invention. In addition, four large LED chips were used as common conditions, and they were not concentrated on the cavity, but were arranged at a sufficient interval around the dam material periphery. Here, the cavity surface of the dam material and the heat dissipating substrate is a high reflectivity surface, the inner surface of the dam material and the cavity surface of the heat dissipating substrate are specular reflection, the other surface is diffuse reflection, and the lens refractive index is 1.51. The stop resin refractive index was 1.41, and the thickness of the heat dissipating substrate as the LED mounting substrate was 0.2 mm.

FIG. 6A is a model of the configuration of FIG. In this model, the dam material 2 has an outer diameter of 11 mm, an inner diameter of 7 mm, a height of 0.6 mm, the lens 7 has a maximum height of 0.8 mm, a maximum diameter of 11.5 mm, and a slope angle of the recess 8 of 42 °. In this model, as shown in the result of FIG. 6B, it can be seen that the light distribution characteristic is substantially centered on the LED light source and has a high lateral light emission component while suppressing the central intensity.
On the other hand, FIG. 7A is a model having the configuration described in FIGS. In this model, the dam material 2 has an outer diameter of 9 mm, an inner diameter of 7 mm, a height of 0.6 mm, the lens 7 has a maximum height of 1.08 mm, a maximum diameter of 16.6 mm, and a slope angle of the recess 8 of 42 °. In this model, as shown in the result of FIG. 7B, it can be seen that the central light emission intensity of the LED light source is considerably suppressed and the light emission intensity toward the side surface is increased. As described above, this model is intended to generate light in the downward direction of the LED light source, but the light distribution angle η shown in FIG. 7A is approximately 60 to 90 ° and approximately −60 to −−. It can be seen that it is a characteristic light source capable of obtaining a large emission intensity at 90 °. Therefore, also from the trial calculation result shown here, the thin large luminous flux LED light source configuration in consideration of the heat dissipation according to the embodiment of the present invention has the effect of increasing the side (including the lower side) light emission intensity. You can say that.

  As described above, an object of the present invention is to obtain a large luminous flux light source with good heat dissipation, and the number of LED chips 3 may be made larger than that in FIG. FIGS. 8A and 8B are configuration examples in the case of using five LED chips 3 that have a larger luminous flux than the four LED chips shown in FIG. FIG. 8A shows an example in which five LED chips are arranged on the dam material 2 side on the cavity of the heat-radiating substrate 1 in order to suppress the temperature rise of each LED chip. The same arrangement is possible with 6 or more LED chips, and when the number of LED chips is increased, the outer shape of the LED package part 6 is not necessarily circular, but it is oval, square, rectangular, etc. In addition, the lens 7 may have the characteristics described above. FIG. 8B also shows a case where there are five LED chips, one being the central arrangement and the other four being arranged at the periphery. In the case of FIG. 8B, the light flux toward the light source center slightly increases.

  On the other hand, the present invention is also applicable to the case where a light beam is not required as in FIG. For example, FIG. 8 (c) shows three LED chips arranged at the periphery, FIG. 8 (d) shows a spatial light distribution that is asymmetrical in the left and right, top and bottom, but two LED chips are arranged at the periphery, and FIG. 8 (e) This is an example in which one LED chip is arranged in the center. Although the above description is based on the assumption that a large LED chip is used, one or more regular LED chips (surface area 0.3 × 0.3 mm, about 0.07 W) and middle LED chips (large chip and regular chip) are used. It is applicable even when used.

Embodiment 2. FIG.
9 shows an LED light source according to Embodiment 2 of the present invention. FIG. 9A is a top view, and FIG. 9B and FIG. 9C are cross-sectional views thereof. Here, each LED chip 3 is surrounded by the first dam material 31 so that the area is as small as possible, and the portion surrounded by the first dam material 31 is a fluorescent material-containing resin 30 mixed with the fluorescent material 4. It is an example sealed with. This embodiment is relatively easy to manufacture and less expensive than the embodiment of FIG. 1 in which the fluorescent material 4 is provided only on the surface of the LED chip 3. The first dam material 31 may be configured as a cylindrical material provided with a hole surrounding each LED chip 3. Further, another second dam material 32 may be formed on the first dam material 31 and the inside thereof may be sealed with the translucent resin 5. With such a configuration, when the entire cavity space as shown in FIG. 1 is sealed with a sealing material including the fluorescent material 4, a wide area of the entire cavity becomes a diffusion light emitting region. It is possible to suppress the lens effect from fading.

  Therefore, as shown in FIG. 9B, the fluorescent material-containing resin 30 is disposed only in the peripheral region of the LED chip 3, and the initial light emission source around the LED chip 3 is diffused so as not to be diffused light over a wide area. It is good also as a structure which restrict | limits the range of light to LED chip 3 surface vicinity. As in the configuration of FIG. 1, the shape of the lens 7 increases toward the upper part of the LED chip 3, and a concave part 8 that is recessed toward the LED chip 3 is formed in the vicinity of the upper part. At this time, by forming the surface of the concave portion 8 with the highly reflective material 10 as shown in FIG. 3, it is possible to obtain an LED light source having higher emission intensity in the lateral direction.

In FIG. 9C, an intermediate light guide material layer 35 is formed in which the upper region of the fluorescent material-containing resin 30 surrounded by the first dam material 31 is a cavity 36, and is located at a position corresponding to the upper surface of the cavity 36. In this configuration, the vertex of the concave portion of the lens is located. By making the inner surface of the cavity 36 a highly reflective material, the fluorescence conversion light is radiated along the cavity 36 regardless of the material of the intermediate light guide material layer 35. Also in this configuration, light can be efficiently emitted to the concave portion 8 of the lens 7, and the side emission intensity can be increased by changing the direction of the light on the inclined surface 8 a of the concave portion 8.
The configuration using the intermediate light guide material layer 35 in FIG. 9C can also be applied to a configuration in which the fluorescent material 4 in FIG. 1 is provided on the surface of the LED chip 3, and the LED light emission is on the high reflectance side surface. The light is efficiently emitted to the vicinity of the lens recess by suppressing the diffused light emission area to about the area of the LED chip 3 and thus has an effect of improving the light control to the side.

Embodiment 3 FIG.
FIG. 10 shows an LED light source according to Embodiment 3 of the present invention. FIG. 10 (a) is a top view, FIG. 10 (b) is a side sectional view of FIG. 10 (a), and FIG. It is a sectional side view which shows the modification of FIG.10 (b). Here, a fluorescent sheet 33 in which a fluorescent material is resin-bound is used as the fluorescent material 4. 9B, as in FIG. 9B, the inside of the first dam material 31 provided for each LED chip 3 is sealed with a light-transmitting sealing resin 5, and is positioned on the sealing resin 5. This is an example in which such a fluorescent sheet 33 is arranged. In this configuration, the second dam material 32 is further disposed on the upper portion, and the inside thereof is sealed with a light-transmitting sealing resin 5.
In FIG. 10C, the fluorescent sheet 34 covering the plurality of LED chips 3 is arranged on the first dam material 31, and the upper part corresponds to each LED chip 3 as in FIG. 9C. The intermediate light guide material layer 35 having the hollow portion 36 as a portion to be formed is formed. Even with such a configuration, the light emission area of the initial diffusion light source can be reduced, and the light control effect to the side of the LED light source can be enhanced by cooperation with the lens configuration described so far. In this case as well, by forming the highly reflective material 10 on the surface 8a of the recess 8, it is possible to obtain an LED light source having higher emission intensity in the lateral direction.

  Furthermore, as shown in FIG. 11, for example, a fluorescent material 40 in which a phosphor is mixed with a resin may be added to the lens 7 in advance. In this case, it is configured to have a fluorescent layer (fluorescent material 40) having an area substantially equal to that of the LED chip 3 at the arrangement position of the LED chip 3 on the back surface of the lens 7. Even in such a configuration, it is easy to control the light of the wavelength-converted light to the side of the inverted conical surface of the concave portion 8 without expanding the fluorescent diffused light region. In FIG. 11B, an intermediate light guide material layer 35 that surrounds the periphery of the chip 3 with a highly reflective material as in the configuration of FIG. 10 is provided, the irradiation direction of the LED light source is limited to some extent, and a fluorescent layer ( The fluorescent material 40) is arranged. In this example, the sealing portion (translucent sealing resin 5) has a slightly dome shape in order to enhance light extraction. FIG. 11C shows a fluorescent layer (fluorescent material 40) disposed on the back surface of the lens 7, and FIG. 11D shows a depression formed on the rear surface of the lens 7 and a fluorescent layer (fluorescent material 40) disposed on the region. ) Has a configuration in which a convex portion 37 is provided in a portion corresponding to the position of the LED chip 3 on the back surface of the lens 7 and a fluorescent layer (fluorescent material 40) is arranged on the surface thereof. Note that (e) shows only the lens side surface in (d).

  At this time, if this fluorescent material region is assumed to be a large region, for example, covering the entire region of the package, diffused light enters from a wide region on the back surface of the lens 7, and the light control effect by the lens 7 is greatly lost. The light distribution of the light source is close to completely diffuse light emission with less side light emission component which is not intended in the present invention. Therefore, by adopting the configuration as described above, it is possible to efficiently irradiate the fluorescence conversion region limited to about the same area as the light emitting region of the LED chip 3 and to irradiate the light emitting region of the wavelength-converted diffused light with the area of the LED chip 3. A light source that can be suppressed to a small extent and that has a high lateral light control effect can be obtained.

Embodiment 4 FIG.
Next, a light emitter using the LED light source according to the present invention (hereinafter referred to as the present LED light source) will be described. The light emitter incorporating the LED light source can take various forms such as a light guide plate method, a direct illumination method that does not use a light guide plate, and an indirect illumination method. Here, a planar light emitter such as a backlight of a liquid crystal display is used here. An application to the (light guide plate) and a configuration for increasing the luminous efficiency of the light emitter will be described.
FIG. 12 shows Embodiment 4 using this LED light source, and is an example of a planar light guide plate in which the LED light source of the present invention can be incorporated. FIG. 12 (a) shows the upper surface of the surface of the light guide plate. Fig. 12 (b) is a side view of 12 (a). In FIG. 12, 15 is a light guide plate made of a translucent resin, 16 is an LED light source housing part (consisting of recesses, openings, etc.) in which the LED light source is arranged, 17 is a side surface provided around the light guide plate 15 A light guide plate case having a reflective material. When the illumination area is relatively small, the LED light source is centrally arranged as shown by a solid line, and when large area illumination is required, for example, the LED light source is arranged at a plurality of locations as indicated by dotted lines. If this LED light source is used, even when large area illumination is required, the number of use can be significantly reduced as compared with the case of using a small luminous flux LED light source.

  FIG. 13 is a cross-sectional structure diagram of a planar light emitter according to Embodiment 4 in which the LED light source is used in the side surface region Z including the recess 16 of the light guide plate 15 of FIG. The LED light source is disposed in the LED light source housing 16 provided on the light guide plate 15. A heat dissipating material 18 is provided on the back surface of the LED light source. Further, around the heat dissipating material 18, a highly reflective material 19 that reflects the light radiated in the package back surface direction and enters the light guide plate 15 is provided. By doing in this way, it can be set as the structure which is easy to radiate the heat | fever (LED chip heat_generation | fever) which this LED light source emits via the back surface of an LED light source. At this time, a heat dissipation member, a heat diffusion member, a heat transfer member, or the like may be provided on the back side of the heat dissipation material 18 to further improve the heat dissipation. Further, the laying of the highly reflective material 19 makes it possible to reflect the light distribution component downward from the side of the LED light source, and to enter the light guide plate 15. Therefore, with the structure as shown in FIG. 13, the light is incident on the light guide plate 15 with high incidence efficiency with respect to the LED light source (configuration example of FIG. 3) that has been actively designed to enhance the light distribution downward of the light source. Can be made.

  In addition, a back light control pattern laying portion 20 is provided on the back surface of the light guide plate 15 (the surface in contact with the highly reflective material 19) to provide a light transmission and diffusion carrying function. Further, in the present light emitter, the light source housing side surface light control unit 21 is provided on the side surface of the LED light source housing unit 16, and the light source housing unit lens facing surface light control unit 22 is provided on the surface of the LED light source housing unit 16 facing the lens 7. Yes. Thereby, the brightness | luminance equalization of the light-guide plate 15 surface is performed with respect to the light radiated | emitted especially above this LED light source. These control units 21 and 22 are configured by providing light control structures or materials. For example, the light guide plate surface brightness uniformity is increased by arranging thin film paint dot printing or a spatial light density modulation film in the areas of these control units 21 and 22.

  Further, as shown in FIG. 14, as the light source housing side light control unit 21 around the LED light source 23, for example, an uneven shape (fine prism shape) 24 extending in a stripe shape from the back surface of the light guide plate having a height of about several tens of μm is added. For example, the surface area may be increased to increase the incident efficiency while utilizing the light refraction effect on the surface.

Further, as shown in FIG. 15 (a), the shape of the light guide plate 15 corresponding to the light source housing side light controller 21 in FIG. 13 has a gently curved surface that follows the surface shape of the LED light source. You may comprise as follows. In that case, the air layer (light source accommodating part 16) between this LED light source and the light-guide plate 15 can be decreased, and incident efficiency can be improved. Or the part can also be comprised as the step-shaped part 26 which made the step shape like FIG.15 (b). By doing in this way, the side upward light component of light distribution (For example, light distribution shown by FIG.6 (b) and 7 (b)) can be suppressed using refraction and total reflection.
Further, on the surface of the light guide plate 15, in the region located in the direction where the light distribution intensity of the LED light source is high, or in the vicinity thereof, thin film printing of a reflective pattern, light density modulation film attachment, or direct addition of a fine uneven shape, etc. The light density adjusting unit 27 may be provided to perform luminance equalization. In addition, if the light-transmitting resin is filled in the gap between the air layers, the difference in the refractive index of the layer between the lens 7 of the LED light source and the light guide plate 15 can be reduced. Incidence efficiency to the light plate 15 is further increased and light emission efficiency is improved.

  In the first to fourth embodiments described above, the lens 7 has a configuration in which the thickness of the lens 7 becomes thinner toward the peripheral end as shown in FIGS. 1 and 3, and the outer shape of the lens 7 is slightly larger than the package diameter. Although the effect has been described with the example of the lens 7 shape as shown in FIG. 16, a flat surface (a cylindrical side surface) such that the outer diameter of the lens 7 is equal to the package diameter and the side surface of the lens 7 rises substantially vertically as shown in FIG. May be formed (see a cross-sectional view of FIG. 16B). In the case of this configuration, the light emission ratio from the side surface of the lens 7 having a large area is increased as the diameter is reduced, and thus the side light emission effect direction is provided.

  17 and 18 show a simulation model (a) and a light distribution characteristic trial calculation result (b) when the side surface of the lens 7 is a flat surface. FIG. 17 is the same as the diameter of the lens 7 in the configuration of FIG. 7, with the dam material having an outer diameter of 9 mm, an inner diameter of 7 mm, a height of 0.6 mm, the lens having a maximum height of 0.72 mm, a maximum diameter of 9 mm, and a recess. This is the result when the slope angle is 42 °. The model angle direction of FIG. 17A and the axis of the result of FIG. 17B are the same as those of FIG. 6, and it can be seen that the side light emission effect from FIG. FIG. 18 shows a configuration in the case where there is no dam material in FIG. 17, and in this case, it can be seen that the light extraction amount at the side (large angle) is increased.

In addition, as another lens surface shape, for example, as shown in FIG. 20, a configuration in which four LED chips 3 are mounted, and a concave portion 8 such as an inverted cone is formed immediately above the LED chip 3 in FIGS. 20 (b) and 20 (c). The side irradiation effect can be obtained even with a cylindrical configuration having the concave shape 8 in which the center of the lens 7 in FIG. 20D is thin. Here again, the inverted conical recess 8 is configured so that a half of its apex angle is a total reflection angle, and a circular area formed by the intersection of the surface and the inverted cone surrounds the LED chip 3. ing. In any case, the LED chip 3 is mounted in a depression provided in each LED chip unit (in the first dam material 31 facing the recess 8) and sealed with a sealing material 38 mixed with a phosphor. Further, as shown in the drawing, the second dam material 32 is formed as necessary, and the inside thereof is sealed with a highly transparent sealing resin.
FIG. 21 and FIG. 22 show simulation models and trial calculation results when the cavity surface is specularly reflected for these configurations. FIG. 21 is formed so that the surface of each LED chip 3 is surrounded by a highly reflective dam material 2 as shown in FIG. 16B (a disk-shaped dam material opened only at four locations around the LED chip 3). This is a configuration in which a lens having a height of 1.1 mm, a diameter of 9 mm, and a concave slope angle of 42 ° is disposed on a 0.8 mm-thick package part having a second dam material 32 formed thereon. FIG. 22 corresponds to FIG. 20D, and the surface of the lens 7 has a concave shape with a large curvature. In either case of FIG. 21 or FIG. 22, the front luminous intensity is suppressed and the side emission amount is increased.

Further, FIG. 23 shows a configuration in which the diameter is further reduced, and results when the package part diameter is 6 mm, the height is 0.4 mm, the surface flat lens height is 1.1 mm, the diameter diameter is 6 mm, and the concave slope angle is 42 °. It is. From the above results, it can be seen that the side radiation effect is maintained even when the size is reduced.
In addition, FIGS. 24E and 24F show a configuration example in the case of using one LED chip having a considerably large size (for example, 1.5 mm × 1.5 mm size). Even in such a configuration, an LED light source having a high lateral intensity and a high luminous flux can be obtained by using a heat radiating material as a package base and providing a lens having an inverted conical recess 8 under the same conditions as described above. . FIG. 25 shows the simulation model (example in which a lens having a height of 1.2 mm, a diameter of 3.0 mm, and a concave slope angle of 42 ° is arranged on a 0.8 mm-thick package part) and the light distribution trial calculation result. It can be seen that this case also has a side radiation effect.

  Further, for a cylindrical light source having a wide side surface of the lens 7 as shown in FIGS. 16 and 20, the opening of the light guide plate 15 is simply formed as a hollow surface as shown in FIG. It can be used in a configuration in which it substantially contacts the side surface. In this case, the gap formed between the lens 7 and the light guide plate 15 can be extremely reduced, and the difference in refractive index in the light traveling path can be reduced, so that the reflection light incident efficiency of the light guide plate is small. Therefore, it is possible to obtain a light emitting body having a high light emission efficiency.

  In addition, as shown in FIG. 27, only the side surface (light irradiation unit) of the lens 7 may be in contact with the light guide plate 15. When the package side face is in contact with the light guide plate opening side face as shown in FIG. 26 in a configuration that does not emit light sideways from the dam material 2 part of the package part 6, there is no opportunity for light to enter from that part, and the package part height In order to approach the surface of the light guide plate 15 only, the proportion of light emitted directly from the opening of the light guide plate 15 increases. In the structure of FIG. 27, the opening side surface region of the light guide plate 15 can be made wider than the side surface area of the lens 7, so that the opportunity for light emitted from the lens to enter the light guide plate 15 increases. Therefore, this configuration makes it possible to obtain a light emitter with high light guide plate incidence efficiency. At this time, the heat dissipating material 18 on the back surface of the package portion may be configured to have a recess that accommodates the package portion and that holds down the highly reflective material 19. With the above configuration, it is possible to improve the light emission efficiency while maintaining the package heat dissipation effect.

FIGS. 28 and 29 show configuration examples in which the LED package 6 of FIGS. 20C and 24F is disposed in the concave portion of the light guide plate 15, respectively. In this example, the surface of the package substrate of the LED package 3 is formed of a highly reflective material so that the side surface portion of the lens 7 and the side surface portion of the light guide plate 15 are in contact with the recess of the light guide plate 15 having a lens size. Since the lens 7 portion is thin and small in diameter, the opening size of the LED light source installation portion of the light guide plate 15 can be reduced with respect to the thin light guide plate 15, while suppressing the light emission intensity directly above the LED light source, and in the center direction of the LED light source. About a light component, it is comprised so that the light-diffusion effect or partial light attenuation effect may be given by the light source arrangement recessed part upper surface light control part 22 as needed, and the light emission uniformity on the surface of a light-guide plate may be raised.
In the example of FIG. 27, FIG. 28, or FIG. 29, the lens diameter of the LED light source is reduced, and the thermally conductive package portion is configured to be clearly larger than the lens diameter. With such a configuration, the heat transfer area can be widened against the large heat generated by the high-power LED chip, and the back surface of the metal light guide plate case having a large area as shown in FIGS. 27, 28, and 29. By forming a heat radiation path in close contact with each other, it is possible to obtain a light-emitting body with good luminous efficiency that suppresses the LED chip temperature rise.
Further, for a columnar LED light source such as this configuration, as shown in FIG. 19, from the surface of luminous efficiency improvement and light distribution control, for example, prisms, cylindrical stripes, etc. in the vertical direction of the side surface of the lens 7 You may comprise so that the uneven | corrugated shape 7a may be added.

  With the configuration described above, surface light emission is achieved by providing a light control function according to the light distribution characteristics of the LED light source 23 on the side surface of the light guide plate 15 facing the region where the LED light source 23 is disposed or on the surface of the light guide plate 15. It becomes possible to improve luminous efficiency and luminance uniformity as a body. In the present embodiment, the configuration relating to the improvement of the characteristics of the light emitter using the LED light source has been described by taking a planar light emitter intended for the light guide plate as an example. According to the configuration, a light emitter having good characteristics in terms of light distribution and heat can be obtained.

  As described above, the present invention relates to an LED light source having a large luminous flux, a thin shape, and a high lateral emission intensity, and a light emitting body using the LED light source. It can be used for a wide range of applications such as LCD and liquid crystal backlights.

  DESCRIPTION OF SYMBOLS 1 Heat radiation board | substrate, 2 Dam material, 3 LED chip, 4 Fluorescent material, 5 Sealing resin (translucent resin), 6 LED package part, 7 Lens, 8 Recessed part, 9 Lens periphery light distribution countermeasure part, 10 Reflective member , 15 Light guide plate, 16 LED light source accommodating portion, 17 Light guide plate case, 18 Heat radiating material, 19 Highly reflective material, 20 Back light control pattern laying portion, 21 Light source accommodating portion side light control portion, 22 Light source accommodating portion facing the lens Surface light control unit, 23 LED light source, 24 concave / convex shape (or fine prism shape), 26 stepped shape portion, 27 light density adjustment unit, 30 fluorescent material-containing resin, 31 first dam material, 32 second dam material, 33 Fluorescent material, 34 Fluorescent material, 35 Intermediate light guide material layer, 36 Opening.

Claims (30)

An LED package part in which at least one LED chip is mounted on a heat dissipating substrate, and the LED chip is sealed with a translucent material;
A lens that is disposed on the LED package part and has a concave portion formed on the LED chip side immediately above each LED chip; and
The lens is
The shape of the recess is an inverted cone or an inverted polygonal pyramid having an apex angle on a substantially central axis of the LED chip, and the thickness of the lens gradually increases from the start end of the recess toward the outer peripheral end of the lens. An LED light source characterized by having a curved shape that becomes thinner.   The LED light source according to claim 1, wherein an outer peripheral end portion of the lens is formed so as to protrude from an outer peripheral end of the LED package portion.   3. The LED light source according to claim 1, wherein the slope of the concave portion of the lens is formed of a light reflective material.   The LED light source according to any one of claims 1 to 3, wherein the lens is formed so that a lens thickness of a start end portion of the concave portion is maximized.   The LED light source according to any one of claims 1 to 4, wherein a plurality of the LED chips are scattered in a mounting region of the heat-radiating substrate and are mounted and spaced apart from each other.   The LED light source according to claim 1, wherein the plurality of LED chips are mounted and arranged in an annular shape at substantially equal intervals.   The LED light source according to claim 1, wherein the LED chip mounting side surface of the heat dissipating substrate has specular reflectivity.   8. The slope according to claim 1, wherein the slope that forms the apex angle of the inverted cone or the inverted polygonal pyramid-shaped recess is a slope that totally reflects at least part of the light emitted from the LED chip. The LED light source of crab.   The LED light source according to any one of claims 1 to 8, wherein a diameter of a start end of the concave portion of the lens is equal to or larger than a diagonal dimension of the LED chip.   The LED light source according to claim 1, wherein a flat surface is included on an outer peripheral surface of a start end of the concave portion of the lens.   The LED light source according to claim 1, wherein an outer peripheral end shape of the lens is circular.   The LED light source according to claim 11, wherein the lens includes a cylindrical shape having a flat side surface.   The LED light source according to claim 12, wherein unevenness processing is formed on a side surface of the cylindrical region of the lens including the cylindrical region.   14. The light emitting device according to any one of claims 1 to 13, wherein a dam material provided with light reflectivity is provided at least on the surface around the LED chip, and the translucent material is filled inside the dam material. The LED light source of crab.   The LED light source according to claim 1, wherein the heat dissipation substrate is a metal or a ceramic material.   The LED light source according to any one of claims 1 to 15, wherein the LED package portion includes a fluorescent material that emits light of excitation light to the LED chip and emits light of a different color or wavelength from the LED chip.   The LED light source according to claim 16, wherein the fluorescent material is a fluorescent material layer laminated on an upper surface or a side surface of the LED chip.   The LED light source according to claim 1, further comprising a fluorescent material on a back surface of a lens corresponding to the LED chip arrangement position.   The said LED package part has the dam material enclosed for every LED chip, and sealed the inner side of the said dam material with the translucent resin containing the fluorescence material of Claims 1-16 characterized by the above-mentioned. The LED light source in any one.   The LED package portion has a dam material surrounded by each LED chip, the inside of the dam material is filled with a light-transmitting resin, and a sheet-like fluorescent material is provided on the upper surface of each LED chip. The LED light source according to any one of claims 1 to 16.   The LED package portion has an opening having a size corresponding to an inner portion of the dam material on a surface facing the lens, and an intermediate light guide material layer having an inner surface of the opening as light reflectivity. 21. The LED light source according to claim 19 or 20, wherein:   The LED light source according to claim 21, wherein a convex portion that can be inserted into the opening is formed on the back surface of the lens, and a fluorescent material is provided on the surface of the convex portion.   A light emitter comprising the LED light source according to any one of claims 1 to 22 and a translucent light guide member combined.   24. The light emitter according to claim 23, wherein the translucent light guide member is a light guide plate having a recess or an opening for accommodating the LED light source.   The light emitter according to claim 24, wherein a region outside the outer peripheral edge of the back surface of the LED light source is covered with a light reflective material.   26. The light emitter according to claim 24, wherein a light control member or a light control structure that contributes to brightness uniformity of transmitted light is provided on a surface of the light transmissive light guide member facing the LED light source. .   27. The light emitter according to any one of claims 24 to 26, wherein a concavo-convex shape extending vertically in stripes is formed on a surface of the translucent light guide member facing the LED light source side end surface. .   The side surface shape of the LED light source housing part of the translucent light guide member is a curved shape or a staircase shape along the lens shape of the LED light source. Luminous body.   The light emitting body according to any one of claims 24 to 28, wherein a space formed between the translucent light guide member and the LED light source is filled with a translucent resin.   30. The light emitter according to any one of claims 24 to 29, wherein only a lens portion of the LED light source is disposed in the LED light source installation region of the light emitter.

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