JP6858494B2 - LED lighting device - Google Patents

Description

The present invention relates to an LED lighting device mounted on various lighting fixtures.

In recent years, a lighting device using a plurality of light emitting elements has been adopted as a light source for lighting instead of a light bulb or a fluorescent lamp. The light emitting element has lower power consumption than a light bulb or the like, but its directivity is narrow because it is a point-shaped light source. For this reason, dozens to hundreds of light emitting elements are used in the LED lighting device, and by sealing these light emitting elements with a translucent resin, a light emitting surface having uniform brightness is formed. doing.

In the above-mentioned light emitting element, since a large amount of light is emitted from the light emitting layer (PN junction) toward the upper surface of the mounting substrate, sufficient brightness in the front direction may not be obtained in some cases. In order to improve this, the light emitted in the lateral direction is emitted by forming the mounting substrate on which the LED is mounted with a material having high reflectance or by providing a reflecting member around the light emitting element on which the LED is mounted. Is reflected in the front direction to increase the brightness in the front direction.

In Patent Document 1, by forming the upper surface of the mounting substrate on which the light emitting element is mounted as a rough surface composed of a set of fine irregularities, the light directed from the light emitting layer of the light emitting element toward the upper surface of the mounting substrate is directed in the front direction. A light emitting device configured to be directed is disclosed.

Further, in Patent Document 2, by providing an electrode surface inclined at a predetermined angle on the electrode surface on which the light emitting element is mounted, the light directed from the light emitting layer of the light emitting element toward the upper surface of the mounting substrate is directed in the front direction. The light emitting device is disclosed.

Japanese Unexamined Patent Publication No. 2009-289918 Japanese Unexamined Patent Publication No. 2010-171116

In the light emitting device disclosed in Patent Document 1, the mounting surface of the mounting substrate on which the light emitting element is mounted is formed of a material having high light reflectance, or the mounting surface is formed as a rough surface. Therefore, it is possible to obtain a reflection effect toward the upper side of the mounting surface (front of the light emitting surface). However, simply selecting a member having a high light reflectance or roughening the mounting surface causes variations in the reflectance of the light toward the front surface of the light emitting, and there is a problem that uniform and high-brightness light emission cannot be obtained. ..

On the other hand, in the light emitting device disclosed in Patent Document 2, since it is necessary to provide an inclined reflecting surface separately from the mounting substrate and the electrodes, a plurality of light emitting elements are densely packed on such a reflecting surface. There is a problem that it is not suitable for mass production because it is difficult to form it on the mounting substrate to be arranged.

Therefore, an object of the present invention is to uniformly reflect the light emitted from the surroundings of each light emitting element toward the upper side of the mounting substrate in the mounting substrate on which a plurality of light emitting elements are arranged and mounted, thereby increasing the overall height. It is an object of the present invention to provide an LED lighting device capable of obtaining a uniform light emission effect with brightness and no uneven light emission or variation.

In order to solve the above problems, the LED lighting device of the present invention is an LED lighting device including a plurality of light emitting elements and a mounting substrate having a mounting surface on which the plurality of light emitting elements are mounted. Each mounted light emitting element is provided with a reflecting portion that surrounds the light emitting element, and the reflecting portion has an inclined surface that is inclined from the outer peripheral portion in four directions of the bottom surface on which the light emitting element is mounted. The upper end of the inclined surface is lower than the height of the light emitting layer of the light emitting element, and has an inclination angle for reflecting the light emitted from the light emitting layer in the direction directly above the mounting surface.

According to the LED lighting device according to the present invention, a mounting surface on which a plurality of light emitting elements are mounted is provided so as to surround each light emitting element, and has an inclined surface that inclines downward toward the light emitting element. Since it is formed by the reflecting portion, the light emitted from each light emitting element toward the mounting surface can be uniformly reflected upward toward the mounting surface. As a result, the light emitted directly upward from each of the light emitting elements and the reflected light from the periphery of each light emitting element can illuminate the upper part of the mounting surface with high brightness and uniformly.

It is a perspective view centering on the mounting surface of the LED lighting device of this invention. It is a perspective view which shows the whole of the said LED lighting apparatus. 1 is a plan view (a), a sectional view (b) of AA, and a sectional view (c) of BB of the mounting surface of the first embodiment. It is sectional drawing of the main part of the mounting surface of 1st Embodiment. 2 is a plan view (a), a sectional view (b) of AA, and a sectional view (c) of BB of the mounting surface of the second embodiment. 3 is a plan view (a), a sectional view (b) of AA, and a sectional view (c) of BB of the mounting surface of the third embodiment. It is sectional drawing of the main part of the mounting surface of 3rd Embodiment. 4 is a plan view (a), a sectional view (b) of AA, and a sectional view (c) of BB of the mounting surface of the fourth embodiment.

FIG. 1 shows the LED lighting device 11 of the first embodiment of the present invention. The LED lighting device 11 includes a mounting board 12 and a wiring board 13 arranged on the mounting board 12 and having a circular opening 14 in the center, and the mounting board exposed through the opening 14. A mounting surface 15 in which a plurality of light emitting portions 21 including a light emitting element 16 and an inclined reflecting portion 23 surrounding the light emitting element 16 are continuous is formed on the light emitting element 16.

The mounting substrate 12 is made of a metal material having a high light reflectance and thermal conductivity of a dozen mm to several tens of mm square depending on the lighting application and the lighting scale, and the mounting surface 15 is provided at the center thereof. Be done.

In the wiring board 13, a pair of electrode bands 14a and 14b are formed along the edge of the opening 14, and the electrode bands 14a and 14b are formed on a pair of electrode terminals 20a and 20b for electrical connection with the outside. Each is electrically connected. One of the pair of electrode bands 14a and 14b is an anode and the other is a cathode.

The light emitting element 16 mounted on the mounting surface 15 uses a blue light emitting element of the same type and size made of a gallium nitride based compound semiconductor in order to emit a white light emitting color for general lighting. This blue light emitting element is composed of a substrate made of sapphire glass and a diffusion layer in which an n-type semiconductor and a p-type semiconductor are diffused and grown on the substrate. The n-type semiconductor and the p-type semiconductor are provided with an n-type electrode and a p-type electrode on the upper surface, respectively, and are electrically connected to each other via a wire 19. In the present embodiment, a plurality of light emitting elements 16 are formed by a plurality of array groups connected in series, and the light emitting elements 16 located at both ends of each array group are connected to any of the electrode bands 14a and 14b. Then, a predetermined current is applied to each of the array groups via the pair of electrode terminals 20a and 20b.

As shown in FIG. 2, around the opening 14, a partition frame 17 made of an insulating resin along the upper surfaces of the electrode bands 14a and 14b of the wiring board 13 is formed at a predetermined height, and the partition frame 17 is formed. A translucent sealing resin 18 is formed inside. The sealing resin 18 is formed by impregnating a transparent resin base material with a predetermined amount of a fluorescent agent. For example, yttrium aluminum garnet, which is a raw material for fluorescent particles, is formed on an epoxy resin or silicone resin base material. It can be formed by mixing an appropriate amount of a fluorescent agent made of (YAG) or a dye which is a raw material of dye particles.

Next, the configuration of the mounting surface 15 will be described with reference to FIGS. 3 and 4. Here, FIG. 3A is a plan view of the mounting surface 15, and FIGS. 3B and 3C are a sectional view taken along the line AA and a sectional view taken along the line BB of the mounting surface 15. The plurality of light emitting portions 21 constituting the mounting surface 15 are all uniformly formed, and each light emitting portion 21 has a bottom surface 22 on which the light emitting element 16 is mounted and a mortar-shaped inclined reflection surrounding the bottom surface 22. It is provided with a unit 23. Therefore, each light emitting unit 21 constitutes one independent light emitting area by itself, and by assembling a plurality of each light emitting unit 21 on the mounting surface 15, the entire predetermined illumination region is bright and uniform. Can be illuminated. The bottom surface 22 of each light emitting portion 21 is provided at a position where the mounting substrate 12 is recessed in a rectangular shape in the thickness direction, and the reflecting portion 23 is formed in a square shape in a plan view and is mounted on the bottom surface 22. It is formed by four trapezoidal inclined surfaces 24 that incline downward toward the light emitting element 16. As shown in FIG. 4, each of the inclined surfaces 24 has its upper end 25 set at a position lower than the light emitting layer 16a of the light emitting element 16 so as to reflect the light emitted downward from the light emitting layer 16a. It has become.

As shown in FIG. 3, the mounting surface 15 is formed so that the light emitting portions 21 are continuous in a grid pattern in the vertical and horizontal directions. Therefore, the reflecting portion 23 of each light emitting portion 21 is connected to the reflecting portion 23 of the adjacent light emitting portion 21 by a ridge line 26 formed at the upper end 25 of each inclined surface 24, and is adjacent to the ridge line 26 as a boundary. The light reflected by the light emitting element 16 of the light emitting unit 21 does not affect each other.

By etching the upper surface of the mounting substrate 12, the mounting surface 15 can collectively form a plurality of light emitting portions 21 including the bottom surface 22 and the reflecting portion 23. Further, the mounting substrate 12 can also be formed by using a mold formed along the uneven shape of the mounting surface 15 composed of the arrangement of the plurality of light emitting portions 21.

As shown in FIG. 4, the inclined surface 24 constituting the reflecting portion 23 of each light emitting portion 21 is 10 to 25 degrees from the outer peripheral portion in four directions of the bottom surface 22 on which the light emitting element 16 is mounted. It is formed by the angle of inclination. As shown in FIG. 4A, when the inclination angle α1 of the inclined surface 24 is 25 degrees, the light in the range of the emission angle β1 of about 50 degrees from the light emitting layer 16a of the light emitting element 16 is said. By being reflected near the upper end 25 of the inclined surface 24, a large amount of reflected light can be obtained in a direction substantially directly above the mounting surface 15 (front surface of light emission). On the other hand, as shown in FIG. 4B, when the inclination angle α2 of the inclined surface 23 is 10 degrees, light having an emission angle β2 of about 20 degrees is emitted from the light emitting layer 16a of the light emitting element 16. By being reflected by the inclined surface 24 near the bottom surface 22, a large amount of reflected light toward the front surface of the light emitting can be obtained.

When the inclination angle of the inclined surface 24 is increased in this way, the light emitted from the light emitting layer 16a of the light emitting element 16 is reflected toward the front of the light emitting surface at a position close to the upper end 25 of the inclined surface 24. On the contrary, when the inclination angle of the inclined surface 24 is reduced, the light emitted from the light emitting layer 16a of the light emitting element 16 is directed toward the front of the light emitting near the bottom surface 22 on which the light emitting element 16 is mounted. Can be reflected. Therefore, as in the present embodiment, by setting the inclination angle of the inclined surface 24 to the range of 10 degrees to 25 degrees, the reflected light toward the front of the emitted light is increased without emission loss in each light emitting unit 21. Luminous efficiency can be increased.

Since the mounting surface 15 of the present embodiment is composed of an aggregate of light emitting parts 21 composed of rectangular reflecting parts 23 in a plan view, it is directly emitted from a light emitting element 16 mounted in the center of each reflecting part 23. The light and the reflected light having a rectangular emission contour from each reflection unit 23 are combined, and the front surface of the emission can be illuminated evenly and with high brightness.

FIG. 5 shows a configuration example of the mounting surface 30 of the second embodiment. The mounting surface 30 of this embodiment is formed by an aggregate of a light emitting portion 31 including a bottom surface 32 on which the light emitting element 16 is mounted and a circular mortar-shaped reflecting portion 33 surrounding the bottom surface 32. Therefore, each light emitting unit 31 constitutes one independent light emitting area by itself, and by assembling a plurality of each light emitting unit 31 on the mounting surface 30, the entire predetermined illumination region is bright and uniform. Can be illuminated.

The reflecting portion 33 forms the tilt angle of the inclined surface 34 in the range of 10 degrees to 25 degrees as in the first embodiment, so that the light emitting element 16 extends between the top 35 of the inclined surface 34. It is possible to obtain reflected light toward the front of the light emitting light that is emitted downward from the light emitting layer 16a at a predetermined angle and substantially directly above the mounting surface 30.

Since the reflecting portion 33 of each light emitting unit 31 is formed in a circular shape in a plan view centered on the light emitting element 16, the bottom surface 32 on which the light emitting element 16 is mounted is shifted by a half space as shown in FIG. By arranging them in this way, more light emitting elements 16 can be integrated in the mounting surface 30. According to this arrangement, the reflecting portions 33 of each light emitting portion 31 are connected by an arc-shaped ridge line 36 in which the reflecting portion 33 of the adjacent light emitting unit 31 and the upper end 35 of each inclined surface 34 are in contact with each other, with the ridge line 36 as a boundary. The light reflected by the light emitting element 16 of the adjacent light emitting unit 31 does not affect each other.

Further, in the present embodiment, since the reflecting portion 33 of each light emitting portion 31 is formed by a circular inclined surface 34 centered on the light emitting element 16, the inclined surface within the same range from the light emitting layer 16a of the light emitting element 16. All the light reflected by 34 can be reflected at the same angle. Therefore, concentric light emission centered on the light emitting element 16 is obtained from each light emitting unit 31, and the concentric light emission spreads over the entire mounting surface 30 to illuminate the front surface of the light emitting with evenly high-intensity light. can do.

FIG. 6 shows a configuration example of the mounting surface 40 of the third embodiment. The mounting surface 40 of this embodiment is formed by an aggregate of a light emitting portion 41 including a bottom surface 42 on which the light emitting element 16 is mounted and a reflecting portion 43 having a function as a Fresnel lens surrounding the bottom surface 42. .. Each of the light emitting units 41 constitutes one independent light emitting area by itself, and by assembling a plurality of the light emitting units 41 on the mounting surface 40, the entire predetermined illumination region is brightly and uniformly illuminated. be able to.

As shown in FIG. 7, in the reflecting portion 43, minute inclined surfaces 44 that incline downward toward each light emitting element 16 are continuously formed, and one Fresnel is formed between adjacent light emitting elements 16. It forms a lens surface. The inclination angle of each of the inclined surfaces 44 is set in the range of 10 degrees to 25 degrees as in the first and second embodiments.

Each of the plurality of inclined surfaces 44 extends stepwise around the light emitting element 16, and the upper end 45 of the inclined surface 44 located on the outermost side of each light emitting unit 41 is connected to another adjacent light emitting unit 41. It is a continuous ridge line 46 that divides the reflection area of.

The light emitted from the light emitting layer 16a of each light emitting element 16 is reflected by the plurality of inclined surfaces 44, so that a large amount of light can be reflected toward the light emitting front surface substantially directly above the mounting surface 40. Further, since the directions of inclination of the plurality of inclined surfaces 44 are reversed with the ridge line 46 as a boundary, the reflected light does not interfere with the adjacent light emitting elements 16. Therefore, even when a plurality of light emitting portions 41 are continuously formed on the mounting surface 40, the reflection regions do not overlap between the adjacent light emitting elements 16, so that the brightness in front of the light emitting is made uniform. be able to.

FIG. 8 shows a configuration example of the mounting surface 50 of the fourth embodiment. In the mounting surface 50 of this embodiment, the reflecting portion 53 surrounding the light emitting element 16 mounted on the bottom surface 52 is formed in a circular shape in a plan view, and a plurality of minute inclined surfaces 54 similar to those in FIG. 7 are arranged concentrically. It is a thing. Therefore, each light emitting unit 51 constitutes one independent light emitting area by itself, and by assembling a plurality of each light emitting unit 51 on the mounting surface 50, the entire predetermined illumination region is bright and uniform. Can be illuminated.

Since the shapes and angles of the plurality of inclined surfaces 54 constituting the reflecting portion 53 are the same as those of the embodiment shown in FIG. 7, the description thereof will be omitted. In this embodiment, in order to arrange the light emitting unit 51 in close contact with the mounting surface 50 without any gap, as shown in FIG. 5, the light emitting elements 16 adjacent to each other in the vertical and horizontal directions are shifted by half a space. In the present embodiment, reflected light having a concentric shape centered on the light emitting element 16 and having high light collecting property is obtained from each light emitting unit 51, and the concentric reflected light spreads over the entire mounting surface 50, whereby the light emitting front surface. Can be illuminated with high-intensity light evenly.

Each of the plurality of inclined surfaces 54 spreads concentrically around the light emitting element 16, and the upper end 55 of the inclined surface 54 located on the outermost side of each light emitting portion 51 reflects with the adjacent light emitting portion 51. It is a continuous ridge line 56 that divides the area.

As described above, in the LED lighting device of the present invention, since the mounting surface is formed by aggregating independent light emitting parts including a light emitting element and a reflecting part surrounding the light emitting element, they are individually formed. There is no variation in the light emitted from the light emitting portion of the above, and uniform and high-intensity light emission can be obtained on the entire mounting surface. Further, since the reflecting portion surrounding the light emitting element has an inclined surface whose angle is set so as to direct the light emitted downward from the light emitting layer of the light emitting element toward the light emitting front surface substantially directly above the mounting surface. , A lighting effect with high light-collecting property can be obtained.

11 LED lighting device 12 Mounting board 13 Wiring board 14 Opening 14a, 14b Electrode band 15 Mounting surface 16 Light emitting element 16a Light emitting layer 17 Partition frame 18 Sealing resin 19 Wire 20a, 20b Electrode terminal 21 Light emitting part 22 Bottom surface 23 Reflecting part 24 Inclined surface 25 Upper end 26 Ridge line 30 Mounting surface 31 Light emitting part 32 Bottom surface 33 Reflecting part 34 Inclined surface 35 Upper end 36 Ridge line 40 Mounting surface 41 Light emitting part 42 Bottom surface 43 Reflecting part 44 Inclined surface 45 Upper end 46 Ridge line 50 Mounting surface 51 53 Reflector 54 Inclined surface 55 Upper end 56 Ridge line

Claims (5)

L including a plurality of light emitting elements and a mounting substrate having a mounting surface on which the plurality of light emitting elements are mounted.
In the ED lighting device
For each light emitting element to be mounted, a reflecting portion surrounding the light emitting element is provided on the mounting surface.
The reflecting portion is formed by a Fresnel lens surface composed of a plurality of minute inclined surfaces inclined from the outer peripheral portions of the bottom surface in which the light emitting element is mounted in four directions, and the upper end of the inclined surface is the light emitting layer of the light emitting element. An LED lighting device having an inclination angle that is lower than the height of the above and reflects light emitted from the light emitting layer in a direction directly above the mounting surface. The LED lighting device according to claim 1, wherein the reflecting portion is formed in a square shape in a plan view, and a light emitting element is mounted in the center thereof. The LED lighting device according to claim 1, wherein the inclined surface of the reflecting portion has an inclined angle for reflecting light emitted obliquely downward from each light emitting element toward substantially directly upward. The LED lighting device according to claim 3, wherein the inclination angle of the inclined surface is in the range of 10 degrees to 25 degrees. The LED lighting device according to claim 1, wherein the reflecting portion is connected to an adjacent reflecting portion by a ridge line formed at the upper end of an inclined surface.

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