JP2016018893A - Light-emitting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light-emitting device capable of enhancing the condensing performance, while suppressing up-sizing of an optical system.SOLUTION: A light-emitting device 1 includes a light-emitting component 10, a condenser lens 20, and a reflection member 30. The condenser lens 20 has an emitting surface 26, a first recess 12, a second recess 14, and a first reflection surface 21. The first recess 12 is concave to the opposite side of the emitting surface 26. The first recess 12 includes a first light incident surface 22 directing the light-emitting surface 11. When the LED light from the light-emitting surface 11 impinges on the first light incident surface 22, the incident light from the first light incident surface 22 is reflected by the first reflection surface 21 to the emitting surface 26. The first recess 12 covers the light-emitting surface 11. The reflection member 30 surrounds the first reflection surface 21 from the outside of the first recess 12, receives the light having an emission angle θ in the vicinity of 90 degrees, out of the emission light of the light-emitting component 10, and reflects that light to the emitting surface 26. The reflection member 30 is arranged on the side face side of the condenser lens 20.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a light emitting device used for illumination.

  Conventionally, condensing system spotlights and downlights using LEDs are provided with one condensing lens for each LED, and multiple LEDs and condensing lens arrays are arranged by the required amount of light. The system is configured. 7-9 is a figure which shows an example of the conventional light-emitting device. The light emitting device 100 illustrated in FIG. 7 includes seven LED lens assemblies 102. The LED lens assembly 102 includes a condenser lens 104 and an LED package 106. FIG. 8 is a cross-sectional view of the LED lens assembly 102, and shows a cross section taken along line AA of FIG. The condensing lens for LED is generally composed of a convex lens portion and a reflective lens portion. FIG. 9 is a perspective view of the LED package 106. An LED element unit 108 is mounted on the substrate 110.

  10 and 11 are diagrams showing another example of a conventional light emitting device. A light emitting device 120 shown in FIG. 10 includes a condenser lens 121 and a COB (Chip On Board) type LED package 126. The LED package 126 is a package in which LED elements are surface-mounted on a substrate. FIG. 11 is a perspective view of the LED package 126, and the LED element portion 128 is provided on the substrate 130. Recently, with the advent of high-intensity COB-type LEDs, light-emitting devices using only one COB as a light source have appeared. This light-emitting device has the advantage that the graininess of appearance can be eliminated compared with the light-emitting device 100 in which a plurality of LEDs are arranged as shown in FIGS. 7 to 9, and multi-shadows generated after irradiation of an object are suppressed. There is an advantage that you can. On the other hand, as problems, there are a problem that the height dimension H of the optical system becomes large as shown in FIG. 10 and a problem that the beam angle is difficult to narrow (regardless of the type of light source, If you try to squeeze the corners, the optical system size will increase.)

  In order to solve the problem that the optical system becomes large, a technique for thinning a lens by using a Fresnel lens method is known as in Patent Document 1 below.

JP 2012-104256 A

  Light-emitting components with LEDs mounted on the surface are widespread, but this type of light-emitting component has a relatively large light-emitting surface area. When a condensing lens used for such a light-emitting component is made into a Fresnel lens, the finer the Fresnel structure, the more light that cannot be controlled unless the distance between the condensing lens and the light-emitting component is increased. . Increasing the distance between the condenser lens and the light emitting component increases the size of the optical system. In the method of converting the condensing lens into a Fresnel lens as in Patent Document 1, there is a problem that the optical system size cannot be reduced even if the thickness of the condensing lens can be reduced, and both the condensing performance and the downsizing of the optical system are compatible. From this point of view, there was still room for improvement.

  SUMMARY An advantage of some aspects of the invention is to provide a light emitting device capable of improving the light collecting performance while suppressing an increase in the size of the optical system.

  A light-emitting device according to the present invention includes a light-emitting component having a light-emitting surface, an output surface, and a first recess having a first light incident surface that is concave on the opposite side of the output surface and faces the light-emitting surface. A first reflecting surface that reflects incident light from the first light incident surface toward the exit surface, and a condensing lens that is disposed so that the first recess faces the light emitting surface; A reflecting member that surrounds the first reflecting surface from the outside of the first recess, receives light that is not incident on the first recess among the emitted light of the light emitting component, and reflects the light toward the emitting surface; Is provided.

  According to the present invention, since the condensing lens and the reflecting member are arranged so that efficient condensing can be performed based on the light distribution, it is possible to improve the condensing performance while suppressing an increase in the size of the optical system. it can.

It is sectional drawing which shows the light-emitting device concerning embodiment of this invention. It is a figure showing the ratio of the emission angle and the amount of luminous flux according to the type of light source. It is a figure which shows the output angle of a light emitting component. It is a figure for demonstrating the structure of the light-emitting device concerning embodiment of this invention. It is a figure which shows the modification of the light-emitting device concerning embodiment of this invention. It is a figure which shows the modification of the light-emitting device concerning embodiment of this invention. It is a figure which shows an example of the conventional light-emitting device. It is a figure which shows an example of the conventional light-emitting device. It is a figure which shows an example of the conventional light-emitting device. It is a figure which shows the other example of the conventional light-emitting device. It is a figure which shows the other example of the conventional light-emitting device.

  FIG. 1 is a cross-sectional view showing a light emitting device 1 according to an embodiment of the present invention. The light emitting device 1 includes a light emitting component 10, a condenser lens 20, and a reflecting member 30. The light-emitting component 10 is a so-called COB (Chip On Board) type light-emitting component, and includes a substrate, an LED element that is surface-mounted on the substrate, and wiring that connects the substrate and the LED element. The light emitting component 10 has a light emitting surface 11 from which LED light is emitted. The light emitting device 1 is a light emitting device on which only one light emitting component 10 is mounted. The three-dimensional shape of the condenser lens 20 is obtained by rotating the cross section of the condenser lens 20 shown in FIG. 1 around the central axis.

  The condensing lens 20 has an exit surface 26, a first recess 12, a second recess 14, and a first reflecting surface 21. In the condenser lens 20, the outer surface of the first recess 12 is the first reflecting surface 21. The first recess 12 is concave on the opposite side of the emission surface 26. The condenser lens 20 is disposed immediately above the light emitting component 10, and is disposed so that the first concave portion 12 faces the light emitting surface 11. The first recess 12 includes a first light incident surface 22 facing the light emitting surface 11 side. When the LED light from the light emitting surface 11 is incident on the first light incident surface 22, the incident light is reflected by the first reflecting surface 21 toward the emission surface 26. The light emitting surface 11 and the emission surface 26 are provided substantially in parallel, and the first light incident surface 22 is substantially perpendicular to the emission surface 26. The first reflecting surface 21 is inclined so that the first recess 12 tapers as it approaches the light emitting surface 11 from the emission surface 26 side.

  The 2nd recessed part 14 is provided inside the 1st recessed part 12, and has the front-end | tip 14a. The tip 14 a is lower than the tip 12 a of the first recess 12. That is, the tip 14a protrudes smaller than the tip 12a from the emission surface 26 side. The second recess 14 includes a second light incident surface 24 facing the light emitting surface 11 side, and a second reflective surface 23 that reflects incident light from the second light incident surface 24 toward the output surface 26. The condenser lens 20 includes a convex refracting lens portion 16 facing the light emitting surface 11 inside the second concave portion 14. The convex refracting lens unit 16 includes a convex refracting surface 25 provided immediately above the light emitting surface 11.

  The condensing lens for LED is generally composed of a convex lens portion and a reflective lens portion. In this respect, in the condensing lens 20 according to the embodiment, the convex refracting lens portion 16 forms a “convex lens portion”, and the first reflecting surface 21 and the first light incident surface 22 of the first concave portion 12 are “ The second reflection surface 23 and the second light incident surface 24 included in the second concave portion 14 constitute a “second reflection lens portion”.

  Although the exit surface 26 is a flat surface without a step, the present invention is not limited to this, and the convex lens portion may be biconvex like the condensing lens 104. As described above, a concave portion may be formed by hollowing out the upper portion of the incident surface 125. The first reflecting surface 21 and the second reflecting surface 23 may be curved in the sectional view of FIG. 1, or may be flat surfaces in the sectional view of FIG. Further, one of the first reflecting surface 21 and the second reflecting surface 23 may be a flat surface and the other may be a curved surface. Further, in the present embodiment, the first light incident surface 22 and the second light incident surface 24 are flat surfaces in the sectional view of FIG. 1, but may be curved surfaces in the sectional view of FIG. One of the first light incident surface 22 and the second light incident surface 24 may be a flat surface and the other may be a curved surface.

  The reflection member 30 surrounds the first reflection surface 21 from the outside of the first recess 12, receives light having an emission angle θ of around 90 degrees, and reflects the light to the emission surface 26 side. To do. The reflecting member 30 is disposed on the side surface side of the condenser lens 20.

  In FIG. 1, light emitted from the light emitting component 10 is illustrated by being divided into a direction, b direction, c direction, and d direction. For the sake of convenience of explanation, the vertical direction in FIG. 1 is referred to as “vertical direction” or “height direction”.

  The light in the a direction is first reflected by the reflecting member 30, and finally, some of the light is emitted from the emission surface 26 although control is not effective. The light in the b direction is first incident on the first light incident surface 22, and most of the light enters the condenser lens 20. Then, the light is totally reflected by the first reflecting surface 21, travels in the vertical direction, and is emitted from the exit surface 26. The light in the c direction is first incident on the second light incident surface 24, and most of the light enters the condenser lens 20. Next, the light is totally reflected by the second reflecting surface 23, travels in the vertical direction, and is emitted from the exit surface 26. The light in the d direction is first incident on the convex refracting surface 25, and most of it enters the condenser lens 20. Then, the light is refracted in the vertical direction and emitted from the emission surface 26.

  In the embodiment, the inner side surface 31 of the reflecting member 30 is not perpendicular to the emission surface 26 but has an angle so that the light in the a direction can easily come out. The inner surface 31 does not contact the first reflecting surface 21 and a gap is provided between them. The reflection member 30 is preferably a highly reflective member, and the inner side surface 31 that reflects light in the direction a is preferably white or silver.

  FIG. 2 is a diagram showing the ratio of the emission angle θ and the amount of light flux. FIG. 2 shows the amount of light flux for each emission angle θ of light emitted from a general COB type light emitting component. For reference, the amount of light flux for each emission angle θ in a lighting device having a beam angle of 20 degrees is also shown. FIG. 3 is a diagram illustrating the emission angle θ of the light emitting component 10. According to FIG. 2, in the light emitting component 10, the ratio of the light traveling in the direction of the emission angle θ = 45 degrees is the highest.

  In FIG. 2, when viewing the luminous flux amount of the emission angle θ = 75 degrees to 90 degrees corresponding to the a direction, this is about 3% of the whole and is small. Even if the light having the emission angle θ = 75 degrees to 90 degrees is not controlled, the final light distribution is not greatly affected, and if the reflectance of the reflecting member 30 is high, the optical system efficiency is hardly lowered. Therefore, in the embodiment, the dimension of the tip 12a of the first recess 12 is designed so that θa is around 70 degrees to 80 degrees, where θa is an emission angle of the light beam intersecting with the point P in FIG. The FIG. 4 is a diagram for explaining the structure of the light-emitting device 1 according to the embodiment of the present invention. A point P in FIG. 4 is the tip 12 a of the first recess 12 as viewed from the light emitting component 10. Thus, by discarding the control of the light having the emission angle θ = 75 degrees to 90 degrees, the first and second light incident surfaces 22 and 24 can be moved away from the light emitting component 10, and the light collecting property is improved. As described above, the output efficiency can be improved by adjusting the position of the tip 12 a of the first recess 12 and reflecting the light in the direction a by the reflecting member 30. Therefore, the light collecting performance can be improved without increasing the size of the optical system.

  Further, according to FIG. 2, in the light emitting component 10, the ratio of the light traveling in the direction of the emission angle θ = 45 degrees is the highest. Therefore, in the embodiment, in addition to the “first reflective lens portion” by the first concave portion 12, a second concave portion 14 is further provided between the central convex refractive lens portion 16 and the outer peripheral first concave portion 12. A “second reflection lens portion” is provided. The condensing lens 20 is formed and arranged so that light in the b direction, c direction, and d direction among the light emitted from the light emitting component 10 can be controlled. Providing the “second reflection lens portion” by forming the second recess 14 does not require an increase in the height of the condenser lens 20. Accordingly, it is possible to reduce the size of the optical system and improve the light collecting performance.

  In order to control the light traveling in the direction of the outgoing angle θ = 45 degrees with the condenser lens 20, the outgoing angle θ of the outgoing light of the light emitting component 10 on the first light incident surface 22 is “greater than 45 degrees to θa or less”. Some light may be incident. On the other hand, for example, light having an emission angle θ of around 45 degrees may be incident on the second light incident surface 24. Alternatively, the emission angle θ of the light incident on the second light incident surface 24 may be adjusted to be equal to or less than “a predetermined angle set to 45 degrees or more”. As described above, the emission angle θa shown in FIG. 4 can be adjusted by adjusting the size of the tip 12a of the first recess 12. Similarly, the maximum value of the emission angle θ of light incident on the second recess 14 (in other words, the maximum value of the emission angle θ of light incident on the second light incident surface 24) protrudes from the tip 14a. Can be adjusted.

  The first light incident surface 22 and the second light incident surface 24 are substantially perpendicular to the light exit surface 26, and the first and second light incident surfaces 22, 24 and the first and second reflective surfaces 21, 23 are as much as possible. It is preferable to shorten the distance. As a result, the ratio of light entering from the first and second light incident surfaces 22 and 24 to the first and second reflecting surfaces 21 and 23 increases, and the first and second light incident surfaces 22 and 24 are also moved away from the light source, and the condenser lens. Loss within 20 is also reduced. However, for convenience of formability, it is preferable to have an angle of several degrees instead of being completely vertical, and the first and second recesses 12 and 14 are located outside the condensing lens 20 toward the distal ends 12a and 14a. It is preferable to incline each of the first and second light incident surfaces 22 and 24 so as to open.

  In the case of the condensing lens 121 shown in FIG. 10 described in the background art, it is difficult to control the condensing of light having an emission angle θ = 45 degrees with a large amount of light when it is thin (that is, when the height dimension H is small). . This point will be described more specifically. First, in the case of a convex lens portion, the ratio of reflecting light having a large emission angle θ by the incident surface 125 increases. Further, in the case of the reflective lens portion, the ratio that light having a small emission angle θ is reflected by the incident surface 123 increases, and the incident light does not hit the reflective surface 124 unless the height dimension H is sufficiently large. Therefore, the light near the intermediate emission angle θ = 45 ° becomes difficult to control when the height dimension H cannot be increased with the lens configuration of FIG. In this regard, the condensing lens 20 according to the embodiment includes the “second reflecting lens portion” configured by the second reflecting surface 23 and the second light incident surface 24, and thus greatly impairs the condensing performance. Therefore, the optical system can be made thinner.

  In the embodiment, one second recess 14 is provided inside the first recess 12, but the present invention is not limited to this, and the second recess 14 may be omitted. Alternatively, the number of other recesses provided inside the first recess 12 may be increased. Specifically, a third recess may be similarly provided inside the second recess 14, and another fourth recess may be further provided. Further, the tip of the third recess may be lower than the tip 14a of the second recess 14, and similarly, the tip of the fourth recess may be made lower than the tip of the third recess.

  FIG. 5 is a diagram showing a modification of the light emitting device 1 according to the embodiment of the present invention. The point which deform | transformed is having reduced the thickness of the condensing lens 20 by providing the flat part 27a in the convex-type refractive lens part 16. FIG. The convex refractive lens unit 16 includes a flat surface portion 27a and a curved surface portion 27b. The flat portion 27a receives light having an emission angle θ from the light emitting surface 11 of 0 degree. The curved surface portion 27b is provided around the flat surface portion 27a and protrudes toward the light emitting surface 11 side. In addition, it is preferable that the area of the flat portion 27a is equal to or smaller than the area of the light emitting surface 11, and thus the central portion can be regarded as having a small amount of light flux and the light source is surface emitting, and the change in light distribution can be reduced.

  FIG. 6 is a diagram showing a modification of the light emitting device 1 according to the embodiment of the present invention. The deformed point is that the fine structure portion 28 is provided on the surface of the emission surface 26. The fine structure portion 28 may be formed by roughening the surface of the emission surface 26 or may be formed by giving a fine lens structure. As a result, the exit surface 26 can be made diffusive, and spectral measures (that is, color breakup measures) can be taken. Instead of providing the fine structure portion 28, a light diffusion sheet may be laid on the surface of the emission surface 26.

DESCRIPTION OF SYMBOLS 1,100,120 Light-emitting device, 10 Light-emitting component, 11 Light-emitting surface, 12 1st recessed part, 12a tip, 14 2nd recessed part, 14a tip, 16 Convex-type refractive lens part, 20, 104, 121 Condensing lens, 21st 1 reflective surface, 22 first light incident surface, 23 second reflective surface, 24 second light incident surface, 25 convex refracting surface, 26 exit surface, 27a flat surface portion, 27b curved surface portion, 28 fine structure portion, 30 reflective member , 31 inner surface, 102 LED lens assembly, 106, 126 LED package, 108, 128 LED element part, 110, 130 substrate, 123, 125 incident surface, 124 reflecting surface

Claims (8)

A light emitting component having a light emitting surface;
An exit surface; a first recess having a concave shape on the opposite side of the exit surface and having a first light entrance surface facing the light emitting surface; and incident light from the first entrance surface of the exit surface. A first reflecting surface that reflects to the side, and a condenser lens that is disposed so that the first recess faces the light emitting surface;
A reflective member that surrounds the first reflective surface from the outside of the first concave portion, receives light that is not incident on the first concave portion of the emitted light of the light-emitting component, and reflects the light toward the outgoing surface;
A light emitting device comprising:   The light emitting device according to claim 1, wherein an angle of the reflecting surface of the reflecting member with respect to the light emitting surface is gentler than an angle of the first reflecting surface with respect to the light emitting surface.   3. The light emitting device according to claim 1, wherein a tip of the first recess intersects with a light beam having an angle of emission from the light emitting component of 70 degrees to 80 degrees. The condensing lens includes a second recess provided inside the first recess,
The tip of the second recess protrudes smaller than the tip of the first recess,
2. The second concave portion has a second light incident surface facing the light emitting surface, and a second reflective surface that reflects incident light from the second light incident surface toward the light emitting surface. The light-emitting device of any one of -3.   The light emitting device according to claim 4, wherein light having an emission angle near 45 ° of the light emitting component is incident on the second recess.   The light-emitting device according to claim 1, wherein the condensing lens includes a convex refracting lens portion facing the light-emitting surface inside the first concave portion.   The convex refractive lens part includes a flat part that receives light having an emission angle of 0 degrees from the light emitting surface, and a curved part that is provided around the flat part and is convex toward the light emitting surface. The light emitting device according to 1.   The light emitting device according to claim 1, wherein unevenness for diffusing light is formed on the emission surface, or a light diffusion sheet is laid on the emission surface.

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